CA2432156A1 - Method and apparatus for manufacturing polymer fiber shells via electrospinning - Google Patents
Method and apparatus for manufacturing polymer fiber shells via electrospinning Download PDFInfo
- Publication number
- CA2432156A1 CA2432156A1 CA002432156A CA2432156A CA2432156A1 CA 2432156 A1 CA2432156 A1 CA 2432156A1 CA 002432156 A CA002432156 A CA 002432156A CA 2432156 A CA2432156 A CA 2432156A CA 2432156 A1 CA2432156 A1 CA 2432156A1
- Authority
- CA
- Canada
- Prior art keywords
- electrode
- precipitation electrode
- precipitation
- subsidiary
- polymer
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
Classifications
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61F—FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS
- A61F2/00—Filters implantable into blood vessels; Prostheses, i.e. artificial substitutes or replacements for parts of the body; Appliances for connecting them with the body; Devices providing patency to, or preventing collapsing of, tubular structures of the body, e.g. stents
- A61F2/82—Devices providing patency to, or preventing collapsing of, tubular structures of the body, e.g. stents
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61F—FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS
- A61F2/00—Filters implantable into blood vessels; Prostheses, i.e. artificial substitutes or replacements for parts of the body; Appliances for connecting them with the body; Devices providing patency to, or preventing collapsing of, tubular structures of the body, e.g. stents
- A61F2/02—Prostheses implantable into the body
- A61F2/04—Hollow or tubular parts of organs, e.g. bladders, tracheae, bronchi or bile ducts
- A61F2/06—Blood vessels
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61F—FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS
- A61F2/00—Filters implantable into blood vessels; Prostheses, i.e. artificial substitutes or replacements for parts of the body; Appliances for connecting them with the body; Devices providing patency to, or preventing collapsing of, tubular structures of the body, e.g. stents
- A61F2/82—Devices providing patency to, or preventing collapsing of, tubular structures of the body, e.g. stents
- A61F2/86—Stents in a form characterised by the wire-like elements; Stents in the form characterised by a net-like or mesh-like structure
- A61F2/90—Stents in a form characterised by the wire-like elements; Stents in the form characterised by a net-like or mesh-like structure characterised by a net-like or mesh-like structure
- A61F2/91—Stents in a form characterised by the wire-like elements; Stents in the form characterised by a net-like or mesh-like structure characterised by a net-like or mesh-like structure made from perforated sheet material or tubes, e.g. perforated by laser cuts or etched holes
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61L—METHODS OR APPARATUS FOR STERILISING MATERIALS OR OBJECTS IN GENERAL; DISINFECTION, STERILISATION OR DEODORISATION OF AIR; CHEMICAL ASPECTS OF BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES; MATERIALS FOR BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES
- A61L27/00—Materials for grafts or prostheses or for coating grafts or prostheses
- A61L27/50—Materials characterised by their function or physical properties, e.g. injectable or lubricating compositions, shape-memory materials, surface modified materials
- A61L27/507—Materials characterised by their function or physical properties, e.g. injectable or lubricating compositions, shape-memory materials, surface modified materials for artificial blood vessels
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61L—METHODS OR APPARATUS FOR STERILISING MATERIALS OR OBJECTS IN GENERAL; DISINFECTION, STERILISATION OR DEODORISATION OF AIR; CHEMICAL ASPECTS OF BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES; MATERIALS FOR BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES
- A61L27/00—Materials for grafts or prostheses or for coating grafts or prostheses
- A61L27/50—Materials characterised by their function or physical properties, e.g. injectable or lubricating compositions, shape-memory materials, surface modified materials
- A61L27/56—Porous materials, e.g. foams or sponges
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C67/00—Shaping techniques not covered by groups B29C39/00 - B29C65/00, B29C70/00 or B29C73/00
- B29C67/20—Shaping techniques not covered by groups B29C39/00 - B29C65/00, B29C70/00 or B29C73/00 for porous or cellular articles, e.g. of foam plastics, coarse-pored
-
- D—TEXTILES; PAPER
- D01—NATURAL OR MAN-MADE THREADS OR FIBRES; SPINNING
- D01D—MECHANICAL METHODS OR APPARATUS IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS
- D01D5/00—Formation of filaments, threads, or the like
- D01D5/0007—Electro-spinning
-
- D—TEXTILES; PAPER
- D01—NATURAL OR MAN-MADE THREADS OR FIBRES; SPINNING
- D01D—MECHANICAL METHODS OR APPARATUS IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS
- D01D5/00—Formation of filaments, threads, or the like
- D01D5/0007—Electro-spinning
- D01D5/0061—Electro-spinning characterised by the electro-spinning apparatus
- D01D5/0069—Electro-spinning characterised by the electro-spinning apparatus characterised by the spinning section, e.g. capillary tube, protrusion or pin
-
- D—TEXTILES; PAPER
- D01—NATURAL OR MAN-MADE THREADS OR FIBRES; SPINNING
- D01D—MECHANICAL METHODS OR APPARATUS IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS
- D01D5/00—Formation of filaments, threads, or the like
- D01D5/0007—Electro-spinning
- D01D5/0061—Electro-spinning characterised by the electro-spinning apparatus
- D01D5/0092—Electro-spinning characterised by the electro-spinning apparatus characterised by the electrical field, e.g. combined with a magnetic fields, using biased or alternating fields
-
- D—TEXTILES; PAPER
- D01—NATURAL OR MAN-MADE THREADS OR FIBRES; SPINNING
- D01D—MECHANICAL METHODS OR APPARATUS IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS
- D01D5/00—Formation of filaments, threads, or the like
- D01D5/18—Formation of filaments, threads, or the like by means of rotating spinnerets
-
- D—TEXTILES; PAPER
- D04—BRAIDING; LACE-MAKING; KNITTING; TRIMMINGS; NON-WOVEN FABRICS
- D04H—MAKING TEXTILE FABRICS, e.g. FROM FIBRES OR FILAMENTARY MATERIAL; FABRICS MADE BY SUCH PROCESSES OR APPARATUS, e.g. FELTS, NON-WOVEN FABRICS; COTTON-WOOL; WADDING ; NON-WOVEN FABRICS FROM STAPLE FIBRES, FILAMENTS OR YARNS, BONDED WITH AT LEAST ONE WEB-LIKE MATERIAL DURING THEIR CONSOLIDATION
- D04H1/00—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres
- D04H1/70—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres characterised by the method of forming fleeces or layers, e.g. reorientation of fibres
- D04H1/72—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres characterised by the method of forming fleeces or layers, e.g. reorientation of fibres the fibres being randomly arranged
- D04H1/728—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres characterised by the method of forming fleeces or layers, e.g. reorientation of fibres the fibres being randomly arranged by electro-spinning
-
- D—TEXTILES; PAPER
- D04—BRAIDING; LACE-MAKING; KNITTING; TRIMMINGS; NON-WOVEN FABRICS
- D04H—MAKING TEXTILE FABRICS, e.g. FROM FIBRES OR FILAMENTARY MATERIAL; FABRICS MADE BY SUCH PROCESSES OR APPARATUS, e.g. FELTS, NON-WOVEN FABRICS; COTTON-WOOL; WADDING ; NON-WOVEN FABRICS FROM STAPLE FIBRES, FILAMENTS OR YARNS, BONDED WITH AT LEAST ONE WEB-LIKE MATERIAL DURING THEIR CONSOLIDATION
- D04H3/00—Non-woven fabrics formed wholly or mainly of yarns or like filamentary material of substantial length
- D04H3/02—Non-woven fabrics formed wholly or mainly of yarns or like filamentary material of substantial length characterised by the method of forming fleeces or layers, e.g. reorientation of yarns or filaments
- D04H3/07—Non-woven fabrics formed wholly or mainly of yarns or like filamentary material of substantial length characterised by the method of forming fleeces or layers, e.g. reorientation of yarns or filaments otherwise than in a plane, e.g. in a tubular way
-
- D—TEXTILES; PAPER
- D04—BRAIDING; LACE-MAKING; KNITTING; TRIMMINGS; NON-WOVEN FABRICS
- D04H—MAKING TEXTILE FABRICS, e.g. FROM FIBRES OR FILAMENTARY MATERIAL; FABRICS MADE BY SUCH PROCESSES OR APPARATUS, e.g. FELTS, NON-WOVEN FABRICS; COTTON-WOOL; WADDING ; NON-WOVEN FABRICS FROM STAPLE FIBRES, FILAMENTS OR YARNS, BONDED WITH AT LEAST ONE WEB-LIKE MATERIAL DURING THEIR CONSOLIDATION
- D04H3/00—Non-woven fabrics formed wholly or mainly of yarns or like filamentary material of substantial length
- D04H3/08—Non-woven fabrics formed wholly or mainly of yarns or like filamentary material of substantial length characterised by the method of strengthening or consolidating
- D04H3/16—Non-woven fabrics formed wholly or mainly of yarns or like filamentary material of substantial length characterised by the method of strengthening or consolidating with bonds between thermoplastic filaments produced in association with filament formation, e.g. immediately following extrusion
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61F—FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS
- A61F2/00—Filters implantable into blood vessels; Prostheses, i.e. artificial substitutes or replacements for parts of the body; Appliances for connecting them with the body; Devices providing patency to, or preventing collapsing of, tubular structures of the body, e.g. stents
- A61F2/02—Prostheses implantable into the body
- A61F2/04—Hollow or tubular parts of organs, e.g. bladders, tracheae, bronchi or bile ducts
- A61F2/06—Blood vessels
- A61F2/07—Stent-grafts
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61F—FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS
- A61F2/00—Filters implantable into blood vessels; Prostheses, i.e. artificial substitutes or replacements for parts of the body; Appliances for connecting them with the body; Devices providing patency to, or preventing collapsing of, tubular structures of the body, e.g. stents
- A61F2/02—Prostheses implantable into the body
- A61F2/04—Hollow or tubular parts of organs, e.g. bladders, tracheae, bronchi or bile ducts
- A61F2/06—Blood vessels
- A61F2/07—Stent-grafts
- A61F2002/072—Encapsulated stents, e.g. wire or whole stent embedded in lining
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61F—FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS
- A61F2210/00—Particular material properties of prostheses classified in groups A61F2/00 - A61F2/26 or A61F2/82 or A61F9/00 or A61F11/00 or subgroups thereof
- A61F2210/0076—Particular material properties of prostheses classified in groups A61F2/00 - A61F2/26 or A61F2/82 or A61F9/00 or A61F11/00 or subgroups thereof multilayered, e.g. laminated structures
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61F—FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS
- A61F2250/00—Special features of prostheses classified in groups A61F2/00 - A61F2/26 or A61F2/82 or A61F9/00 or A61F11/00 or subgroups thereof
- A61F2250/0014—Special features of prostheses classified in groups A61F2/00 - A61F2/26 or A61F2/82 or A61F9/00 or A61F11/00 or subgroups thereof having different values of a given property or geometrical feature, e.g. mechanical property or material property, at different locations within the same prosthesis
- A61F2250/0023—Special features of prostheses classified in groups A61F2/00 - A61F2/26 or A61F2/82 or A61F9/00 or A61F11/00 or subgroups thereof having different values of a given property or geometrical feature, e.g. mechanical property or material property, at different locations within the same prosthesis differing in porosity
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61F—FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS
- A61F2250/00—Special features of prostheses classified in groups A61F2/00 - A61F2/26 or A61F2/82 or A61F9/00 or A61F11/00 or subgroups thereof
- A61F2250/0058—Additional features; Implant or prostheses properties not otherwise provided for
- A61F2250/0067—Means for introducing or releasing pharmaceutical products into the body
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T428/00—Stock material or miscellaneous articles
- Y10T428/13—Hollow or container type article [e.g., tube, vase, etc.]
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T428/00—Stock material or miscellaneous articles
- Y10T428/13—Hollow or container type article [e.g., tube, vase, etc.]
- Y10T428/1352—Polymer or resin containing [i.e., natural or synthetic]
- Y10T428/1372—Randomly noninterengaged or randomly contacting fibers, filaments, particles, or flakes
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T428/00—Stock material or miscellaneous articles
- Y10T428/13—Hollow or container type article [e.g., tube, vase, etc.]
- Y10T428/1352—Polymer or resin containing [i.e., natural or synthetic]
- Y10T428/139—Open-ended, self-supporting conduit, cylinder, or tube-type article
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T428/00—Stock material or miscellaneous articles
- Y10T428/13—Hollow or container type article [e.g., tube, vase, etc.]
- Y10T428/1352—Polymer or resin containing [i.e., natural or synthetic]
- Y10T428/139—Open-ended, self-supporting conduit, cylinder, or tube-type article
- Y10T428/1393—Multilayer [continuous layer]
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T442/00—Fabric [woven, knitted, or nonwoven textile or cloth, etc.]
- Y10T442/60—Nonwoven fabric [i.e., nonwoven strand or fiber material]
- Y10T442/608—Including strand or fiber material which is of specific structural definition
- Y10T442/614—Strand or fiber material specified as having microdimensions [i.e., microfiber]
Abstract
An apparatus for manufacturing a polymer fiber shell from liquefied polymer is provided. The apparatus includes: (a) a precipitation electrode being for generating the polymer fiber shell thereupon; (b) a dispenser, being at a first potential relative to the precipitation electrode so as to generate an electric field between the precipitation electrode and the dispenser, the dispenser being for: (i) charging the liquefied polymer thereby providing a charged liquefied polymer; and (ii) dispensing the charged liquefied polymer in a direction of the precipitation electrode; and (c) a subsidiary electrode being at a second potential relative to the precipitation electrode, the subsidiary electrode being for modifying the electric field between the precipitation electrode and the dispenser.
Description
METHOD AND APPARATUS FOR MANUFACTURING POLYMER
FIBER SHELLS VIA ELECTROSP~G
FIELD AND BACKGROUND OF THE INVENTION
The present invention relates to a method and apparatus for manufacturing polymer fiber shells via electrospinning.
Polymer fiber shells such as tubular shaped products, are used in the medical industry for various utilities including esophageal grafts, vascular grafts, stmt coats and like.
Numerous methods for manufacturing polymer fiber shells suitable for medical applications are known in the art, including, for example, various injection molding methods, mandrel assisted extrusion or formation and various weaving techniques.
Production of polymer fiber shells suitable for use as vascular grafts - is particylarly difficult, since such grafts must withstand high and pulsatile blood pressures while, at the same time, be elastic and biocompatible.
Vascular grafts known in the art typically have a microporous structure that in general allows tissue growth and cell endothelization, thus contributing to long term engraftment and patency of the graft.
In vascular grafts, tissue ingrowth and cell endothelization is typically enhanced with increased in grafts exhibiting increased porosity.
However, increasing the porosity of vascular grafts leads to a considerable reduction of the mechanical and tensile strength of the graft, and as a consequence to a reduction in the functionality thereof.
Electrospinning has been used for generating various products for medical applications, e.g., wound dressings, prosthetic devices, and vascular grafts as well as for industrial use, e.g., electrolytic cell diaphragms, battery separators, and fuel cell components It has already been proposed to produce by electrospinning products having the appearance of shells. For example, U.S. Patent No. 4,323,525 discloses a method of preparing a tubular product by electrostatically spinning a fiber forming material and collecting the resulting spun fibers on a rotating mandrel. U.S. Patent No. 4,552,707 discloses a varying rotation rate mandrel which controls the "anisotropy extent" of fiber orientation of the final product. Additional examples of tubular shaped products and a like .
are disclosed, e.g., in U.S. Patent Nos. 4,043,331, 4,127,706, 4,143,196, 4,223,101, 4,230,650 and 4,345,414.
The process of electrospinning creates a fine stream or jet of liquid that upon proper evaporation yields a non-woven fiber structure. The fine stream of liquid is produced by pulling a small amount of a liquefied polymer (either polymer dissolved in solvent (polymer solution) or melted polymer) through space using electrical forces. The produced fibers are then collected on a suitably located precipitation device, such as a mandrel to form tubular structures. In the case of a melted polymer which is normally solid at room temperature, the hardening procedure may be mere cooling, however other procedures such as chemical hardening or evaporation of solvent may also be employed.
In electrospinning, an electric field with high filed lines density (i.e., having large magnitude per unit volume) may results in a corona discharge near the precipitation device, and consequently prevent fibers from being collected by the precipitation device. The filed lines density of an electric field is determined i~te~ alia by the geometry of the precipitation device; in particular, sharp edges on the precipitation device increase the effect of corona discharge.
In addition, due to the effect of electric dipole rotation along the electric field maximal strength vector in the vicinity of the mandrel, products with at least a section with a small radius of curvature are coated coaxially by the fibers. Such structural fiber formation considerably reduces the radial tensile strength of a spun product, which, in the case of vascular grafts, is necessary for withstanding pressures generated by blood flow.
Various electrospinning based manufacturing methods for generating vascular grafts are known in the prior art, see, for example, U.S. Patent Nos.
FIBER SHELLS VIA ELECTROSP~G
FIELD AND BACKGROUND OF THE INVENTION
The present invention relates to a method and apparatus for manufacturing polymer fiber shells via electrospinning.
Polymer fiber shells such as tubular shaped products, are used in the medical industry for various utilities including esophageal grafts, vascular grafts, stmt coats and like.
Numerous methods for manufacturing polymer fiber shells suitable for medical applications are known in the art, including, for example, various injection molding methods, mandrel assisted extrusion or formation and various weaving techniques.
Production of polymer fiber shells suitable for use as vascular grafts - is particylarly difficult, since such grafts must withstand high and pulsatile blood pressures while, at the same time, be elastic and biocompatible.
Vascular grafts known in the art typically have a microporous structure that in general allows tissue growth and cell endothelization, thus contributing to long term engraftment and patency of the graft.
In vascular grafts, tissue ingrowth and cell endothelization is typically enhanced with increased in grafts exhibiting increased porosity.
However, increasing the porosity of vascular grafts leads to a considerable reduction of the mechanical and tensile strength of the graft, and as a consequence to a reduction in the functionality thereof.
Electrospinning has been used for generating various products for medical applications, e.g., wound dressings, prosthetic devices, and vascular grafts as well as for industrial use, e.g., electrolytic cell diaphragms, battery separators, and fuel cell components It has already been proposed to produce by electrospinning products having the appearance of shells. For example, U.S. Patent No. 4,323,525 discloses a method of preparing a tubular product by electrostatically spinning a fiber forming material and collecting the resulting spun fibers on a rotating mandrel. U.S. Patent No. 4,552,707 discloses a varying rotation rate mandrel which controls the "anisotropy extent" of fiber orientation of the final product. Additional examples of tubular shaped products and a like .
are disclosed, e.g., in U.S. Patent Nos. 4,043,331, 4,127,706, 4,143,196, 4,223,101, 4,230,650 and 4,345,414.
The process of electrospinning creates a fine stream or jet of liquid that upon proper evaporation yields a non-woven fiber structure. The fine stream of liquid is produced by pulling a small amount of a liquefied polymer (either polymer dissolved in solvent (polymer solution) or melted polymer) through space using electrical forces. The produced fibers are then collected on a suitably located precipitation device, such as a mandrel to form tubular structures. In the case of a melted polymer which is normally solid at room temperature, the hardening procedure may be mere cooling, however other procedures such as chemical hardening or evaporation of solvent may also be employed.
In electrospinning, an electric field with high filed lines density (i.e., having large magnitude per unit volume) may results in a corona discharge near the precipitation device, and consequently prevent fibers from being collected by the precipitation device. The filed lines density of an electric field is determined i~te~ alia by the geometry of the precipitation device; in particular, sharp edges on the precipitation device increase the effect of corona discharge.
In addition, due to the effect of electric dipole rotation along the electric field maximal strength vector in the vicinity of the mandrel, products with at least a section with a small radius of curvature are coated coaxially by the fibers. Such structural fiber formation considerably reduces the radial tensile strength of a spun product, which, in the case of vascular grafts, is necessary for withstanding pressures generated by blood flow.
Various electrospinning based manufacturing methods for generating vascular grafts are known in the prior art, see, for example, U.S. Patent Nos.
4,044,404, 4,323,525, 4,738,740, 4,743,252, and 5,575,818. However, such methods suffer from the above inherent limitations which limit the use thereof when generating intricate profile fiber shells.
Hence, although electrospinning can be efficiently used for generating large diameter shells, the nature of the electrospinning process prevents efficient generation of products having an intricate profile and/or small diameter, such as vascular grafts. In particular, since porosity and radial strength are conflicting, prior art electrospinning methods cannot be effectively used for manufacturing vascular grafts having both characteristics.
There is thus a widely recognized need for, and it would be highly advantageous to have, a method and apparatus for manufacturing polymer fiber shells via electrospinning devoid of the above limitations.
SUl~~VIARY OF THE INVENTION
According to one aspect of the present invention there is provided an apparatus for manufacturing polymer fiber shells from liquefied polymer, the apparatus comprising: (a) a precipitation electrode being for generating the polymer fiber shell thereupon; (b) a dispenser, being at a first potential relative to the precipitation electrode so as to generate an electric field between the precipitation electrode and the dispenser, the dispenser being for: (i) charging the liquefied polymer thereby providing a charged liquefied polymer; and (ii) dispensing the charged liquef ed polymer in a direction of the precipitation electrode; and (c) a subsidiary electrode being at a second potential relative to the precipitation electrode, the subsidiary electrode being for modifying the electric field between the precipitation electrode and the dispenser.
According to another aspect of the present invention there is provided a method for forming a liquefied polymer into a non-woven S polymer fiber shells, the method comprising: (a) charging the liquefied polymer thereby producing a charged liquefied polymer; (b) subjecting the charged liquefied polymer to a first electric field; (c) dispensing the charged liquefied polymer within the first electric field in a direction of a precipitation electrode, the precipitation electrode being designed and configured for generating the polymer fiber shell; (d) providing a second electric field being for modifying the first electric field; and (e) using the precipitation electrode to collect the charged liquefied polymer thereupon, thereby forming the non-woven polymer fiber shell.
According to further features in preferred embodiments of the 1 S invention described below, the first electric field is defined between the precipitation electrode and a dispensing electrode being at a first potential relative to the precipitation electrode.
According to still further features in the described preferred embodiments step (c) is effected by dispensing the charged liquefied polymer from the dispensing electrode.
According to still further features in the described preferred embodiments the second electric field is defined by a subsidiary electrode being at a second potential relative to the precipitation electrode.
According to still further features in the described preferred embodiments the subsidiary electrode serves for reducing non-uniformities in the first electric field According to still further features in the described preferred embodiments the subsidiary electrode serves for controlling fiber orientation of the polymer f ber shell generated upon the precipitation electrode.
S
According to still further features in the described preferred embodiments the subsidiary electrode serves to minimize a volume charge generated between the dispenser and the precipitation electrode.
According to still further features in the described preferred embodiments the method further comprising moving the subsidiary electrode along the precipitation electrode during step (e).
According to still further features in the described preferred embodiments the method further comprising moving the dispensing electrode along the precipitation electrode during step (c).
According to still further features in the described preferred embodiments the method further comprising synchronizing the motion of the dispensing electrode and the subsidiary electrode along the precipitation electrode.
According to still further features in the described preferred embodiments the dispenser comprises a mechanism for forming a jet of the charged liquefied polymer.
According to still further features in the described preferred embodiments the apparatus further comprising a bath for holding the liquefied polymer.
According to still further features in the described preferred embodiments the mechanism for forming a jet of the charged liquefied polymer includes a dispensing electrode.
According to still further features in the described preferred embodiments the dispenser is operative to move along a length of the precipitation electrode.
According to still further features in the described preferred embodiments the precipitation electrode includes at least one rotating mandrel.
According to still further features in the described preferred embodiments the rotating mandrel is a cylindrical mandrel.
According to still further features in the described preferred embodiments the rotating mandrel is an intricate-profile mandrel.
According to still further features in the described preferred embodiments the intricate-profile mandrel includes sharp structural elements.
According to still further features in the described preferred embodiments the cylindrical mandrel is of a diameter selected from a range of 0.1 to 20 millimeters.
According to still further features in the described preferred embodiments the precipitation electrode includes at least one structural element selected from the group consisting of a protrusion, an orifice, a groove, and a grind.
According to still further features in the described preferred embodiments the subsidiary electrode is of a shape selected from the group consisting of a plane, a cylinder, a torus and a wire.
According to still further features in the described preferred embodiments the subsidiary electrode is operative to move along a length of the precipitation electrode.
According to still further features in the described preferred embodiments the subsidiary electrode is tilted at angle with respect to a longitudinal axis of the precipitation electrode, the angle is ranging between 45 and 90 degrees.
According to still further features in the described preferred embodiments the subsidiary electrode is positioned at a distance of 5 - 70 millimeters from the precipitation electrode.
According to still further features in the described preferred embodiments the subsidiary electrode is positioned at a distance ~ from the precipitation electrode, 8 being equal to 12(3R(1-V21V1), where ~i is a constant ranging between about 0.7 and about 0.9, R is the curvature-radius of the polymer fiber shell formed on the precipitation electrode, V1 is the first potential and V2 is the second potential.
According to yet another aspect of the present invention there is provided an apparatus for manufacturing a polymer fiber shells from liquefied polymer, the apparatus comprising: (a) a dispenser, for: (i) charging the liquefied polymer thereby providing a charged liquefied polymer; and (ii) dispensing the charged liquefied polymer; and (b) a precipitation electrode being at a potential relative to the dispenser thereby generating an electric field between the precipitation electrode and the dispenser, the precipitation electrode being for collecting the charged liquefied polymer drawn by the electric field, to thereby form the polymer fiber shell thereupon, wherein the precipitation electrode is designed so as to reduce non-uniformities in the electric field.
According to still further features in the described preferred embodiments the precipitation electrode is formed from a combination of electroconductive and non-electroconductive materials.
According to still further features in the described preferred embodiments a surface of the precipitation electrode is formed by a predetermined pattern of the electroconductive and non-electroconductive materials.
According to still further features in the described preferred embodiments the precipitation electrode is formed from at least two layers.
According to still further features in the described preferred embodiments the at least two layers include an electroconductive layer and a partial electroconductive layer.
According to still further features in the described preferred embodiments the partial electroconductive layer is partial electroconductive layer is formed from a combination of an electroconductive material and at least one dielectric material.
According to still further features in the described preferred embodiments the dielectric material is selected from a group consisting of polyamide and polyacrylonitrile and polytetrafluoroethylene.
According to still further features in the described preferred embodiments the dielectric material is Titanium Nitride.
According to still further features in the described preferred embodiments the partial electroconductive layer, is selected of a thickness ranging between 0.1 to 90 microns.
The present invention successfully addresses the shortcomings of the presently known configurations by providing an electrospinning apparatus and method capable of fabricating a non-woven polymer fiber shell which can be used in vascular grafts.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention is herein described, by way of example only, with reference to the accompanying drawings. With specific reference now to the drawings in detail, it is stressed that the particulars shown are by way of example and for purposes of illustrative discussion of the preferred embodiments of the present invention only, and are presented in the cause of providing what is believed to be the most useful and readily understood description of the principles and conceptual aspects of the invention. In this regard, no attempt is made to show structural details of the invention in more detail than is necessary for a fundamental understanding of the invention, the description taken with the drawings making apparent to those skilled in the art how the several forms of the invention may be embodied in practice.
In the drawings:
FIG. 1 is a schematic illustration of a prior art electrospinning apparatus;
FIG. 2 is a schematic illustration of an electrospinning apparatus which includes a subsidiary electrode according to the teachings of the present invention;
FIG. 3 is a schematic illustration of an electrospirming apparatus which includes a planar subsidiary electrode according to the teachings of the present invention;
FIG. 4 is a schematic illustration of an electrospinning apparatus which includes a cylindrical subsidiary electrode according to the teachings of the present invention;
FIG. 5 is a schematic illustration of an electrospinning apparatus which includes a linear subsidiary electrode according to the teachings of the present invention;
FIG. 6 is a schematic illustration of an electrospinning apparatus which includes a composite subsidiary electrode according to the teachings of the present invention;
FIG. 7 is an electron microscope image of material spun using conventional electrospinning techniques;
FIG. 8 is an electron microscope image of material spun using an apparatus which incorporates a flat subsidiary electrode, positioned 20 millimeters from the mandrel, according to the teachings of the present invention;
FIG. 9 is an electron microscope image of material spun using an apparatus which incorporates a flat subsidiary electrode, positioned 9 millimeters from the mandrel, according to the teachings of the present invention; and FIG. 10 is an electron microscope image of polar-oriented material spun using an apparatus which incorporates a linear subsidiary electrode according to the teachings of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention is of a method and an apparatus for manufacturing a polymer fiber shell using electrospinning. Specifically, the present invention can be used to manufacture intricate-profile products and 5 vascular grafts of small to large diameter via electrospinning.
For purposes of better understanding the present invention, as illustrated in Figures 2-10 of the drawings, reference is first made to the construction and operation of a conventional (i.e., prior art) electrospinning apparatus as illustrated in Figure 1.
10 Figure 1 illustrates an apparatus for manufacturing a tubular structure using a conventional electrospinning apparatus, which is referred to herein as apparatus 10.
Apparatus 10 includes a dispenser 12 which can be, for example, a bath provided with capillary apertures 14. Dispenser 12 serves for storing the polymer to be spun in a liquid form. Dispenser 12 is positioned at a predetermined distance from a precipitation electrode 16.
Precipitation electrode 16 serves for generating the tubular structure thereupon. Precipitation electrode 16 is typically manufactured in the form of a mandrel or any other cylindrical structure. Precipitation electrode 16 is rotated by a mechanism such that a tubular structure is formed when coated with the polymer.
Dispenser 12 is typically grounded, while precipitation electrode 16 is connected to a source of high voltage preferably of negative polarity, thus forming an electric field between dispenser 12 and precipitation electrode 16. Alternatively, precipitation electrode 16 can be grounded while dispenser 12 is connected to a source of high voltage, preferably with positive polarity.
To generate a tubular structure, a liquefied polymer (e.g., melted polymer or dissolved polymer) is extruded, for example under the action of hydrostatic pressure, through capillary apertures 14 of dispenser 12. As soon as meniscus forms from the extruded liquefied polymer, a process of solvent evaporation or cooling starts which is accompanied by the creation of capsules with a semi-rigid envelope or crust. An electric field, occasionally accompanied a by unipolar corona discharge in the area of dispenser 12, is generated by the potential difference between dispenser 12 and precipitation electrode 16. Because the liquefied polymer possesses a certain degree of electrical conductivity, the above-described capsules become charged. Electric forces of repulsion within the capsules lead to a drastic increase in hydrostatic pressure. The semi-rigid envelopes are stretched, and a number of point micro-ruptures are formed on the surface of each envelope leading to spraying of ultra-thin jets of liquefied polymer from dispenser 12.
The charges tend to distribute along the jets, thus preventing existence of any non-zero component of electric field inside the jet. Thus, a conduction current flows along the jets, which results in the accumulation of (different sign) free charges on the liquefied polymer surface.
Under the effect of a Coulomb force, the jets depart from the dispenser 12 and travel towards the opposite polarity electrode, i. e., precipitation electrode 16. Moving with high velocity in the inter-electrode space, the jet cools or solvent therein evaporates, thus forming fibers which are collected on the surface of precipitation electrode 16. Since electrode 16 is rotating the charged fibers form a tubular shape.
When using mandrels being at least partially with small radius of curvature, the orientation of the electric field maximal strength vector is ~5 such that precipitation electrode 16 is coated coaxially by the fibers.
Thus, small diameter products, have limited radial strength when manufactured via existing electrospinning methods, as described above.
When using mandrels with sharp edges and/or variously shaped and sized recesses, the electric field magnitude in the vicinity of precipitation electrode 16 may exceed the air electric strength (about 30 kV/cm), and a corona discharge may develop in the area of precipitation electrode 16. The effect of corona discharge decreases the coating efficiency of the process as described hereinbelow, and may even resultant in a total inability of fibers to be collected upon precipitation electrode 16.
Corona discharge initiation is accompanied by the generation of a considerable amount of air ions having opposite charge sign with respect to the charged fibers. Since an electric force is directed with respect to the polarity of charges on which it acts, theses ions start to move at the opposite direction to fibers motion i.e., from precipitation electrode 16 towards dispenser 12. Consequently, a portion of these ions generate a volume charge (ion cloud), non-uniformly distributed in the inter-electrode space, thereby causing electric field lines to partially close on the volume charge rather than on precipitation electrode 16. Moreover, the existence of an opposite volume charge in the inter-electrode space, decreases the electric force on the fibers, thus resulting in a large amount of fibers accumulating in the inter-electrode space and gradually settling under gravity force. It will be appreciated that such an effect leads to a low-efficiency process of fiber coating.
Using an infinite-length/radius cylinder as a precipitation electrode 16 diminishes the effect described above. However, this effect is severe and limiting when small radii or complicated mandrels are employed for fabricating small radius or intricate-profile structures.
Before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement .of the components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments or of being practiced or carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein is for the purpose of description and should not be regarded as limiting.
While reducing the present invention to practice, it was uncovered that the use of a third electrode within an electrospinning apparatus enables to control the electric field generated between the dispenser and precipitation electrode. Specifically, a third electrode may either substantially decreases non-uniformities in the electric field or provides for controlled fiber orientation upon deposition.
Thus, according to the present invention there is provided an apparatus for manufacturing a polymer fiber shell from a liquefied polymer, which apparatus is referred to herein as apparatus 20.
As shown in Figure 2, apparatus 20 includes a precipitation electrode 22 which serves for generating the polymer fiber shell thereupon.
Precipitation electrode 22 can be, for example, a mandrel of uniform or varying radius, which may include some structural elements such as, but not limited to, protrusions, orifices and grooves. The surface of precipitation electrode 22 may also contain grinds. The diameter of the mandrel may vary from about 0.1 millimeter up to about 20 millimeters depending on the diameter of the polymer fiber shell to be spun thereupon.
Apparatus 20 further includes a dispenser 24, which is at a first potential relative to precipitation electrode 22. Such a potential can be generated by grounding dispenser 24, and connecting a source of high voltage with negative polarity to precipitation electrode 22.
Alternatively, precipitation electrode 22 can be grounded while dispenser 24 is connected to a source of high voltage with positive polarity.
In any case, an absolute value for the potential difference between dispenser 24 and precipitation electrode 22 may range between about 10 kV and about 100 kV.
The potential difference between dispenser 24 and precipitation electrode 22 ensures that an electric field is maintained therebetween, which electric field is important for the electrospinning process as described hereinabove.
Dispenser 24 serves for charging the liquefied polymer, thereby providing a charged liquefied polymer and dispensing the charged liquefied polymer in a direction of precipitation electrode 22. Dispenser 24 may also include a mechanism for moving it along a longitudinal axis of precipitation electrode 22, thus enabling dispensing of the charged liquefied polymer at various points along the longitudinal axis of precipitation electrode 22.
The charged liquefied polymer may be, for example polyurethane, polyester, polyolefin, polymethyl methacrylate, polyvinyl aromatic, polyvinyl ester, polyamide, polyimide, polyether, polycarbonate, polyacrilonitrile, polyvinyl pyrrolidone, polyethylene oxide, poly (L-lactic acid), poly (lactide-CD-glycoside), polycaprolactone, polyphosphate ester, poly (glycolic acid), poly (DL-lactic acid), and some copolymers.
Biolmolecules such as DNA, silk, chitozan and cellulose may also be used.
Improved charging of the polymer may also be required. Improved charging is effected according to the present invention by mixing the liquefied polymer with a charge control agent (e.g., a Bipolar additive) to form, for example, a polymer-Bipolar additive complex which apparently better interacts with ionized air molecules formed under the influence of the electric field. It is assumed, in a non-limiting fashion, that the extra-charge attributed to the newly formed fibers is responsible for their more homogenous precipitation on the precipitation electrode, wherein a fiber is better attracted to a local maximum, which is a local position most under represented by older precipitated fibers, which keep their charge for 5-10 minutes. The charge control agent is typically added in the grams equivalent per liter range, say, in the range of from about 0.001 N to about 0.1 N, depending on the respective molecular weights of the polymer and the charge control agent used.
U.S. Pat. Nos. 5,726,107; 5,554,722; and 5,558,809 teach the use of charge control agents in combination with polycondensation processes in the production of electret fibers, which are fibers characterized in a permanent electric charge, using melt spinning and other processes devoid of the use of an precipitation electrode. A charge control agent is added in such a way that it is incorporated into the melted or partially melted fibers and remains incorporated therein to provide the fibers with electrostatic 5 charge which is not dissipating for prolonged time periods, say months.
In a preferred embodiment of the present invention, the charge control agent transiently binds to the outer surface of the fibers and therefore the charge dissipates shortly thereafter (within minutes). This is because polycondensation is not exercised at all such the chemical 10 intereaction between the agent and the polymer is absent, and further due to the low concentration of charge control agent employed. The resulting shell is therefore substantially charge free.
Suitable charge control agents include, but are not limited to, mono-and poly-cyclic radicals that can bind to the polymer molecule via, for 15 example, -C=C-, =C-SH- or -CO-NH- groups, including biscationic amides, phenol and uryl sulfide derivatives, metal complex compounds, triphenylmethanes, dimethylmidazole and ethoxytrimethylsians.
Typically, the charged liquefied polymer is dispensed as a liquid jet, moving at high velocity under electrical forces caused by the electric field.
Thus, dispenser 24 typically includes a bath for holding the liquefied polymer and a mechanism for forming a jet, which mechanism may be, for example, a dispensing electrode.
Apparatus 20 further includes at least one subsidiary electrode 26 which is at a second potential relative to precipitation electrode 22.
Subsidiary electrode 26 serves for controlling the direction and magnitude of the electric field between precipitation electrode 22 and dispenser 24 and as such, subsidiary electrode 26 can be used to control the orientation of polymer fibers deposited on precipitation electrode 22. In some embodiments, subsidiary electrode 26 serves as a supplementary screening electrode. Broadly stated, use of screening results in decreasing the coating precipitation factor, which is particularly important upon mandrels having at least a section of small radii of curvature.
The size, shape, position and number of subsidiary electrode 26 is selected so as to maximize the coating precipitation factor, while minimizing the effect of corona discharge in the area of precipitation electrode 22 and/or so as to provide for controlled fiber orientation upon deposition.
According to one preferred embodiment of the present invention, subsidiary electrode 26 is positioned 5-70 mm away from precipitation electrode 22.
Preferably, such a distance is selected according to the following:
b=l2~iR(1-V2/Vl) (Eq.l) where (3 is a dimensionless constant named a fiber-charge accounting factor, which ranges between about 0.7 and about 0.9, R is the curvature-radius of precipitation electrode 22, Vl is the potential difference between dispenser 24 and precipitation electrode 22 and VZ is the potential difference between subsidiary electrode 26 and precipitation electrode 22.
Subsidiary electrode 26 may include a mechanism for moving it along a longitudinal axis of precipitation electrode 22. Such a mechanism may be in use when enhanced control over fiber orientation is required.
It will be appreciated that in an apparatus in which both dispenser 24 and subsidiary electrode 26 are capable of such longitudinal motion, such motion may be either independent or synchronized.
Subsidiary electrode 26 may also be tilted through an angle of 45-90 degrees with respect to the longitudinal axis of precipitation electrode 22.
Such tilting may be used to provide for controlled fiber orientation upon deposition, hence to control the radial strength of the manufactured shell;
specifically, large angles result in higher radial strength.
In addition to positioning, the shape and size of electrode 26 may also determine the quality of the shell formed by apparatus 20. Thus, electrode 26 may be fabricated in a variety of shapes each serving a specific purpose. Electrode shapes which can be used with apparatus 20 of the present invention include, but are not limited to, a plane, a cylinder, a torus a rod, a knife, an arc or a ring.
An apparatus 20 which includes a subsidiary electrode 26 of a cylindrical (Figure 4) or a flat shape (Figure 3) enables manufacturing intricate-profile products being at least partially with small radius of curvature, which radius may range between 0.025 millimeters and 5 millimeters. As can be seen in Figures 8-9 (further described in the Examples section), the coating of such structures is characterized by random-oriented (Figure 8) or even polar-oriented (Figure 9) fibers, as opposed to an axial coating which is typical for small curvature products manufactured via existing electrospinning methods as demonstrated in Figure 7 (further described in the Examples section).
Preferably, when a surface of large curvature is used as subsidiary electrode 26, as is the case above, the distance between subsidiary electrode 26 and precipitation electrode 22 can be determined as 8/x where x is a factor ranging between 1.8 and 2, and where 8 is as defined by Equation 1 above.
Thus, positioning and/or shape of electrode 26 determines fiber orientation in the polymer fiber shell formed.
The ability to control fiber orientation is important when fabricating vascular grafts in which a high radial strength and elasticity is important.
It will be appreciated that a polar oriented structure can generally be obtained also by wet spinning methods, however in wet spinning methods the fibers are thicker than those .used by electrospinning by at least an order of magnitude.
Control over fiber orientation is also advantageous when fabricating composite polymer fiber shells which are manufactured by sequential deposition of several different fiber materials.
Reference is now made to Figure 5, which illustrates an apparatus 20 which utilizes a linear (e.g., a rod, a knife, an arc or a ring) subsidiary electrode 26.
The effect of subsidiary electrode 26 of linear shape is based on the distortion it introduces to the electric field in an area adjacent to precipitation electrode 22. For maximum effect the diameter of subsidiary electrode 26 must be considerably smaller than that of precipitation electrode 22, yet large enough to avoid generation of a significant corona discharge. Fiber coating generated by apparatus 20 utilizing a linear subsidiary electrode 26 is illustrated by Figure 10 which is further described in the Examples section hereinunder.
Thus, the present invention provides an electrospinning apparatus in which the electric field is under substantial control, thereby providing either random or predetermined fibers orientation.
Although the use of at least one subsidiary electrode is presently preferred, field non-uniformities can also be at least partially overcome by providing a composite precipitation electrode.
As illustrated in Figure 6, precipitation electrode 34 of apparatus 30 having a dispenser 32 can be designed and configured so as to reduce non-uniformities in the electric field.
To overcome field non-uniformities, precipitation electrode 34 is fabricated from at least two layers of materials, an inner layer 36 made of electroconductive material and an outer layer 38 made of a material having high dielectric properties. Such a fabrication design results in a considerable increase of corona discharge threshold thus considerably reducing corona discharge from precipitation electrode 34.
Materials suitable for use with outer layer 38 of precipitation electrode 34, can be ceramic materials e.g., Titanium Nitride, Aluminum Oxide and the like, or polymer materials e.g., polyamide, polyacrylonitrile, polytetrafluoroethylene and the like. The thickness of outer layer 38 depends on the dielectric properties of the material from which it is made and can vary from less than one micron, in the case of, for example, a Titanium Nitride Layer, or tens of microns, in the case of, for example, polytetrafluoroethylene, polyamide or polyacrylonitrile layer. In addition to diminishing corona discharge this precipitation electrode configuration enables easier separation of formed structures therefrom. Thus; according to this configuration outer layer 38 of precipitation electrode 34 can also be configured for facilitating the removal of the final product from the mandrel.
Additional objects, advantages, and novel features of the present invention will become apparent to one ordinarily skilled in the art upon examination of the following' examples, which are not intended to be limiting. Additionally, each of the various embodiments and aspects of the present invention as delineated hereinabove and as claimed in the claims section below finds experimental support in the following examples.
EXAMPLES
Reference is now made to the following examples, which together with the above descriptions, illustrate the invention in a non limiting fashion.
Electrospinniszg Material A polycarbonate resin grade Caliper 2071 was purchased from Daw Chemical Co. This Polymer is characterized as having good fiber forming abilities and is convenient for electrospinning. Chloroform was used as solvent in all of the examples described hereinbelow.
5 Axial Covering Using Conventional Electrospinnisig Method Reference is now made to Figure 7, which is an example of non-randomized covering of thin mandrels via conventional electrospinning. A 3-mm cylindrical mandrel was covered by polycarbonate fiber using prior art electrospinning approaches. Figure 7 is 10 an electron microscope image of the final product, in which axial fiber orientation is well evident. Due to non-uniformities in the electric field, the fibers, while still in motion in the inter-electrode space, are oriented in conformity with the field configuration, and the obtained tubular structure exhibits axial orientation of fibers, and as such is characterized by axial, as 15 opposed to radial strength.
Random Covering Using Flat Subsidiary Electrode An apparatus constructed and operative in accordance with the 20 teachings of the present invention incorporating a flat subsidiary electrode positioned 20 millimeters from the mandrel and having the same potential as the mandrel was used to spin a polycarbonate tubular structure of a 3 mm radius. As is evident from Figure 8, the presence of a subsidiary electrode randomizes fibers orientation.
Polar-Oriented Covering Using Flat Subsidiary electrode An apparatus constructed and operative in accordance with the teachings of the present invention incorporating a flat subsidiary electrode positioned 9 millimeters from the mandrel and being at a potential difference of 5 kV from the mandrel was used to spin a polycarbonate tubular structure of a 3 mm radius.
As illustrated by Figure 9, reduction of equalizing electrode-mandrel distance results in polar-oriented covering. Thus, by keeping subsidiary electrode and mandrel within a relatively small distance, while providing a non-zero potential difference therebetween, leads to slow or no fiber charge dissipation and, as a result, the inter-electrode space becomes populated with fiber which are held statically in a stretched position, oriented perpendicular to mandrel symmetry axis. Once stretched, the fibers are gradually coiled around the rotating mandrel, generating a polar-oriented structure.
E~IlVIPLE 4 Predefined Oriented Coveri~ag UsifZg Linear Subsidiary electrode Figure 10 illustrates result obtained from an apparatus configuration which may be employed in order to obtain a predefined oriented structural fiber covering.
An apparatus which includes an elliptical subsidiary electrode and a dispenser both moving along the longitudinal axis of the mandrel in a reciprocating synchronous movement was used to coat a 3-mm cylindrical mandrel with polycarbonate fiber. The subsidiary electrode had a large diameter of 120 mm, a small diameter of 117.6 mm and a thickness of 1.2 mm. The subsidiary electrode was positioned 15 mm from the mandrel, at an 80 ° tilt with respect to the mandrel symmetry axis.
It is appreciated that certain features of the invention, which are, for clarity, described in the context of separate embodiments, may also be provided in combination in a single embodiment. Conversely, various features of the invention, which are, for brevity, described in the context of a single embodiment, may also be provided separately or in any suitable subcombination.
Although the invention has been described in conjunction with specific embodiments thereof, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art.
Accordingly, it is intended to embrace all such alternatives, modifications and variations that fall within the spirit and broad scope of the appended claims. All publications, patents and patent applications mentioned in this specification are herein incorporated in their entirety by reference into the specification, to the same extent as if each individual publication, patent or patent application was specifically and individually indicated to be incorporated herein by reference. In addition, citation or identification of any reference in this application shall not be construed as an admission that such reference is available as prior art to the present invention.
Hence, although electrospinning can be efficiently used for generating large diameter shells, the nature of the electrospinning process prevents efficient generation of products having an intricate profile and/or small diameter, such as vascular grafts. In particular, since porosity and radial strength are conflicting, prior art electrospinning methods cannot be effectively used for manufacturing vascular grafts having both characteristics.
There is thus a widely recognized need for, and it would be highly advantageous to have, a method and apparatus for manufacturing polymer fiber shells via electrospinning devoid of the above limitations.
SUl~~VIARY OF THE INVENTION
According to one aspect of the present invention there is provided an apparatus for manufacturing polymer fiber shells from liquefied polymer, the apparatus comprising: (a) a precipitation electrode being for generating the polymer fiber shell thereupon; (b) a dispenser, being at a first potential relative to the precipitation electrode so as to generate an electric field between the precipitation electrode and the dispenser, the dispenser being for: (i) charging the liquefied polymer thereby providing a charged liquefied polymer; and (ii) dispensing the charged liquef ed polymer in a direction of the precipitation electrode; and (c) a subsidiary electrode being at a second potential relative to the precipitation electrode, the subsidiary electrode being for modifying the electric field between the precipitation electrode and the dispenser.
According to another aspect of the present invention there is provided a method for forming a liquefied polymer into a non-woven S polymer fiber shells, the method comprising: (a) charging the liquefied polymer thereby producing a charged liquefied polymer; (b) subjecting the charged liquefied polymer to a first electric field; (c) dispensing the charged liquefied polymer within the first electric field in a direction of a precipitation electrode, the precipitation electrode being designed and configured for generating the polymer fiber shell; (d) providing a second electric field being for modifying the first electric field; and (e) using the precipitation electrode to collect the charged liquefied polymer thereupon, thereby forming the non-woven polymer fiber shell.
According to further features in preferred embodiments of the 1 S invention described below, the first electric field is defined between the precipitation electrode and a dispensing electrode being at a first potential relative to the precipitation electrode.
According to still further features in the described preferred embodiments step (c) is effected by dispensing the charged liquefied polymer from the dispensing electrode.
According to still further features in the described preferred embodiments the second electric field is defined by a subsidiary electrode being at a second potential relative to the precipitation electrode.
According to still further features in the described preferred embodiments the subsidiary electrode serves for reducing non-uniformities in the first electric field According to still further features in the described preferred embodiments the subsidiary electrode serves for controlling fiber orientation of the polymer f ber shell generated upon the precipitation electrode.
S
According to still further features in the described preferred embodiments the subsidiary electrode serves to minimize a volume charge generated between the dispenser and the precipitation electrode.
According to still further features in the described preferred embodiments the method further comprising moving the subsidiary electrode along the precipitation electrode during step (e).
According to still further features in the described preferred embodiments the method further comprising moving the dispensing electrode along the precipitation electrode during step (c).
According to still further features in the described preferred embodiments the method further comprising synchronizing the motion of the dispensing electrode and the subsidiary electrode along the precipitation electrode.
According to still further features in the described preferred embodiments the dispenser comprises a mechanism for forming a jet of the charged liquefied polymer.
According to still further features in the described preferred embodiments the apparatus further comprising a bath for holding the liquefied polymer.
According to still further features in the described preferred embodiments the mechanism for forming a jet of the charged liquefied polymer includes a dispensing electrode.
According to still further features in the described preferred embodiments the dispenser is operative to move along a length of the precipitation electrode.
According to still further features in the described preferred embodiments the precipitation electrode includes at least one rotating mandrel.
According to still further features in the described preferred embodiments the rotating mandrel is a cylindrical mandrel.
According to still further features in the described preferred embodiments the rotating mandrel is an intricate-profile mandrel.
According to still further features in the described preferred embodiments the intricate-profile mandrel includes sharp structural elements.
According to still further features in the described preferred embodiments the cylindrical mandrel is of a diameter selected from a range of 0.1 to 20 millimeters.
According to still further features in the described preferred embodiments the precipitation electrode includes at least one structural element selected from the group consisting of a protrusion, an orifice, a groove, and a grind.
According to still further features in the described preferred embodiments the subsidiary electrode is of a shape selected from the group consisting of a plane, a cylinder, a torus and a wire.
According to still further features in the described preferred embodiments the subsidiary electrode is operative to move along a length of the precipitation electrode.
According to still further features in the described preferred embodiments the subsidiary electrode is tilted at angle with respect to a longitudinal axis of the precipitation electrode, the angle is ranging between 45 and 90 degrees.
According to still further features in the described preferred embodiments the subsidiary electrode is positioned at a distance of 5 - 70 millimeters from the precipitation electrode.
According to still further features in the described preferred embodiments the subsidiary electrode is positioned at a distance ~ from the precipitation electrode, 8 being equal to 12(3R(1-V21V1), where ~i is a constant ranging between about 0.7 and about 0.9, R is the curvature-radius of the polymer fiber shell formed on the precipitation electrode, V1 is the first potential and V2 is the second potential.
According to yet another aspect of the present invention there is provided an apparatus for manufacturing a polymer fiber shells from liquefied polymer, the apparatus comprising: (a) a dispenser, for: (i) charging the liquefied polymer thereby providing a charged liquefied polymer; and (ii) dispensing the charged liquefied polymer; and (b) a precipitation electrode being at a potential relative to the dispenser thereby generating an electric field between the precipitation electrode and the dispenser, the precipitation electrode being for collecting the charged liquefied polymer drawn by the electric field, to thereby form the polymer fiber shell thereupon, wherein the precipitation electrode is designed so as to reduce non-uniformities in the electric field.
According to still further features in the described preferred embodiments the precipitation electrode is formed from a combination of electroconductive and non-electroconductive materials.
According to still further features in the described preferred embodiments a surface of the precipitation electrode is formed by a predetermined pattern of the electroconductive and non-electroconductive materials.
According to still further features in the described preferred embodiments the precipitation electrode is formed from at least two layers.
According to still further features in the described preferred embodiments the at least two layers include an electroconductive layer and a partial electroconductive layer.
According to still further features in the described preferred embodiments the partial electroconductive layer is partial electroconductive layer is formed from a combination of an electroconductive material and at least one dielectric material.
According to still further features in the described preferred embodiments the dielectric material is selected from a group consisting of polyamide and polyacrylonitrile and polytetrafluoroethylene.
According to still further features in the described preferred embodiments the dielectric material is Titanium Nitride.
According to still further features in the described preferred embodiments the partial electroconductive layer, is selected of a thickness ranging between 0.1 to 90 microns.
The present invention successfully addresses the shortcomings of the presently known configurations by providing an electrospinning apparatus and method capable of fabricating a non-woven polymer fiber shell which can be used in vascular grafts.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention is herein described, by way of example only, with reference to the accompanying drawings. With specific reference now to the drawings in detail, it is stressed that the particulars shown are by way of example and for purposes of illustrative discussion of the preferred embodiments of the present invention only, and are presented in the cause of providing what is believed to be the most useful and readily understood description of the principles and conceptual aspects of the invention. In this regard, no attempt is made to show structural details of the invention in more detail than is necessary for a fundamental understanding of the invention, the description taken with the drawings making apparent to those skilled in the art how the several forms of the invention may be embodied in practice.
In the drawings:
FIG. 1 is a schematic illustration of a prior art electrospinning apparatus;
FIG. 2 is a schematic illustration of an electrospinning apparatus which includes a subsidiary electrode according to the teachings of the present invention;
FIG. 3 is a schematic illustration of an electrospirming apparatus which includes a planar subsidiary electrode according to the teachings of the present invention;
FIG. 4 is a schematic illustration of an electrospinning apparatus which includes a cylindrical subsidiary electrode according to the teachings of the present invention;
FIG. 5 is a schematic illustration of an electrospinning apparatus which includes a linear subsidiary electrode according to the teachings of the present invention;
FIG. 6 is a schematic illustration of an electrospinning apparatus which includes a composite subsidiary electrode according to the teachings of the present invention;
FIG. 7 is an electron microscope image of material spun using conventional electrospinning techniques;
FIG. 8 is an electron microscope image of material spun using an apparatus which incorporates a flat subsidiary electrode, positioned 20 millimeters from the mandrel, according to the teachings of the present invention;
FIG. 9 is an electron microscope image of material spun using an apparatus which incorporates a flat subsidiary electrode, positioned 9 millimeters from the mandrel, according to the teachings of the present invention; and FIG. 10 is an electron microscope image of polar-oriented material spun using an apparatus which incorporates a linear subsidiary electrode according to the teachings of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention is of a method and an apparatus for manufacturing a polymer fiber shell using electrospinning. Specifically, the present invention can be used to manufacture intricate-profile products and 5 vascular grafts of small to large diameter via electrospinning.
For purposes of better understanding the present invention, as illustrated in Figures 2-10 of the drawings, reference is first made to the construction and operation of a conventional (i.e., prior art) electrospinning apparatus as illustrated in Figure 1.
10 Figure 1 illustrates an apparatus for manufacturing a tubular structure using a conventional electrospinning apparatus, which is referred to herein as apparatus 10.
Apparatus 10 includes a dispenser 12 which can be, for example, a bath provided with capillary apertures 14. Dispenser 12 serves for storing the polymer to be spun in a liquid form. Dispenser 12 is positioned at a predetermined distance from a precipitation electrode 16.
Precipitation electrode 16 serves for generating the tubular structure thereupon. Precipitation electrode 16 is typically manufactured in the form of a mandrel or any other cylindrical structure. Precipitation electrode 16 is rotated by a mechanism such that a tubular structure is formed when coated with the polymer.
Dispenser 12 is typically grounded, while precipitation electrode 16 is connected to a source of high voltage preferably of negative polarity, thus forming an electric field between dispenser 12 and precipitation electrode 16. Alternatively, precipitation electrode 16 can be grounded while dispenser 12 is connected to a source of high voltage, preferably with positive polarity.
To generate a tubular structure, a liquefied polymer (e.g., melted polymer or dissolved polymer) is extruded, for example under the action of hydrostatic pressure, through capillary apertures 14 of dispenser 12. As soon as meniscus forms from the extruded liquefied polymer, a process of solvent evaporation or cooling starts which is accompanied by the creation of capsules with a semi-rigid envelope or crust. An electric field, occasionally accompanied a by unipolar corona discharge in the area of dispenser 12, is generated by the potential difference between dispenser 12 and precipitation electrode 16. Because the liquefied polymer possesses a certain degree of electrical conductivity, the above-described capsules become charged. Electric forces of repulsion within the capsules lead to a drastic increase in hydrostatic pressure. The semi-rigid envelopes are stretched, and a number of point micro-ruptures are formed on the surface of each envelope leading to spraying of ultra-thin jets of liquefied polymer from dispenser 12.
The charges tend to distribute along the jets, thus preventing existence of any non-zero component of electric field inside the jet. Thus, a conduction current flows along the jets, which results in the accumulation of (different sign) free charges on the liquefied polymer surface.
Under the effect of a Coulomb force, the jets depart from the dispenser 12 and travel towards the opposite polarity electrode, i. e., precipitation electrode 16. Moving with high velocity in the inter-electrode space, the jet cools or solvent therein evaporates, thus forming fibers which are collected on the surface of precipitation electrode 16. Since electrode 16 is rotating the charged fibers form a tubular shape.
When using mandrels being at least partially with small radius of curvature, the orientation of the electric field maximal strength vector is ~5 such that precipitation electrode 16 is coated coaxially by the fibers.
Thus, small diameter products, have limited radial strength when manufactured via existing electrospinning methods, as described above.
When using mandrels with sharp edges and/or variously shaped and sized recesses, the electric field magnitude in the vicinity of precipitation electrode 16 may exceed the air electric strength (about 30 kV/cm), and a corona discharge may develop in the area of precipitation electrode 16. The effect of corona discharge decreases the coating efficiency of the process as described hereinbelow, and may even resultant in a total inability of fibers to be collected upon precipitation electrode 16.
Corona discharge initiation is accompanied by the generation of a considerable amount of air ions having opposite charge sign with respect to the charged fibers. Since an electric force is directed with respect to the polarity of charges on which it acts, theses ions start to move at the opposite direction to fibers motion i.e., from precipitation electrode 16 towards dispenser 12. Consequently, a portion of these ions generate a volume charge (ion cloud), non-uniformly distributed in the inter-electrode space, thereby causing electric field lines to partially close on the volume charge rather than on precipitation electrode 16. Moreover, the existence of an opposite volume charge in the inter-electrode space, decreases the electric force on the fibers, thus resulting in a large amount of fibers accumulating in the inter-electrode space and gradually settling under gravity force. It will be appreciated that such an effect leads to a low-efficiency process of fiber coating.
Using an infinite-length/radius cylinder as a precipitation electrode 16 diminishes the effect described above. However, this effect is severe and limiting when small radii or complicated mandrels are employed for fabricating small radius or intricate-profile structures.
Before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement .of the components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments or of being practiced or carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein is for the purpose of description and should not be regarded as limiting.
While reducing the present invention to practice, it was uncovered that the use of a third electrode within an electrospinning apparatus enables to control the electric field generated between the dispenser and precipitation electrode. Specifically, a third electrode may either substantially decreases non-uniformities in the electric field or provides for controlled fiber orientation upon deposition.
Thus, according to the present invention there is provided an apparatus for manufacturing a polymer fiber shell from a liquefied polymer, which apparatus is referred to herein as apparatus 20.
As shown in Figure 2, apparatus 20 includes a precipitation electrode 22 which serves for generating the polymer fiber shell thereupon.
Precipitation electrode 22 can be, for example, a mandrel of uniform or varying radius, which may include some structural elements such as, but not limited to, protrusions, orifices and grooves. The surface of precipitation electrode 22 may also contain grinds. The diameter of the mandrel may vary from about 0.1 millimeter up to about 20 millimeters depending on the diameter of the polymer fiber shell to be spun thereupon.
Apparatus 20 further includes a dispenser 24, which is at a first potential relative to precipitation electrode 22. Such a potential can be generated by grounding dispenser 24, and connecting a source of high voltage with negative polarity to precipitation electrode 22.
Alternatively, precipitation electrode 22 can be grounded while dispenser 24 is connected to a source of high voltage with positive polarity.
In any case, an absolute value for the potential difference between dispenser 24 and precipitation electrode 22 may range between about 10 kV and about 100 kV.
The potential difference between dispenser 24 and precipitation electrode 22 ensures that an electric field is maintained therebetween, which electric field is important for the electrospinning process as described hereinabove.
Dispenser 24 serves for charging the liquefied polymer, thereby providing a charged liquefied polymer and dispensing the charged liquefied polymer in a direction of precipitation electrode 22. Dispenser 24 may also include a mechanism for moving it along a longitudinal axis of precipitation electrode 22, thus enabling dispensing of the charged liquefied polymer at various points along the longitudinal axis of precipitation electrode 22.
The charged liquefied polymer may be, for example polyurethane, polyester, polyolefin, polymethyl methacrylate, polyvinyl aromatic, polyvinyl ester, polyamide, polyimide, polyether, polycarbonate, polyacrilonitrile, polyvinyl pyrrolidone, polyethylene oxide, poly (L-lactic acid), poly (lactide-CD-glycoside), polycaprolactone, polyphosphate ester, poly (glycolic acid), poly (DL-lactic acid), and some copolymers.
Biolmolecules such as DNA, silk, chitozan and cellulose may also be used.
Improved charging of the polymer may also be required. Improved charging is effected according to the present invention by mixing the liquefied polymer with a charge control agent (e.g., a Bipolar additive) to form, for example, a polymer-Bipolar additive complex which apparently better interacts with ionized air molecules formed under the influence of the electric field. It is assumed, in a non-limiting fashion, that the extra-charge attributed to the newly formed fibers is responsible for their more homogenous precipitation on the precipitation electrode, wherein a fiber is better attracted to a local maximum, which is a local position most under represented by older precipitated fibers, which keep their charge for 5-10 minutes. The charge control agent is typically added in the grams equivalent per liter range, say, in the range of from about 0.001 N to about 0.1 N, depending on the respective molecular weights of the polymer and the charge control agent used.
U.S. Pat. Nos. 5,726,107; 5,554,722; and 5,558,809 teach the use of charge control agents in combination with polycondensation processes in the production of electret fibers, which are fibers characterized in a permanent electric charge, using melt spinning and other processes devoid of the use of an precipitation electrode. A charge control agent is added in such a way that it is incorporated into the melted or partially melted fibers and remains incorporated therein to provide the fibers with electrostatic 5 charge which is not dissipating for prolonged time periods, say months.
In a preferred embodiment of the present invention, the charge control agent transiently binds to the outer surface of the fibers and therefore the charge dissipates shortly thereafter (within minutes). This is because polycondensation is not exercised at all such the chemical 10 intereaction between the agent and the polymer is absent, and further due to the low concentration of charge control agent employed. The resulting shell is therefore substantially charge free.
Suitable charge control agents include, but are not limited to, mono-and poly-cyclic radicals that can bind to the polymer molecule via, for 15 example, -C=C-, =C-SH- or -CO-NH- groups, including biscationic amides, phenol and uryl sulfide derivatives, metal complex compounds, triphenylmethanes, dimethylmidazole and ethoxytrimethylsians.
Typically, the charged liquefied polymer is dispensed as a liquid jet, moving at high velocity under electrical forces caused by the electric field.
Thus, dispenser 24 typically includes a bath for holding the liquefied polymer and a mechanism for forming a jet, which mechanism may be, for example, a dispensing electrode.
Apparatus 20 further includes at least one subsidiary electrode 26 which is at a second potential relative to precipitation electrode 22.
Subsidiary electrode 26 serves for controlling the direction and magnitude of the electric field between precipitation electrode 22 and dispenser 24 and as such, subsidiary electrode 26 can be used to control the orientation of polymer fibers deposited on precipitation electrode 22. In some embodiments, subsidiary electrode 26 serves as a supplementary screening electrode. Broadly stated, use of screening results in decreasing the coating precipitation factor, which is particularly important upon mandrels having at least a section of small radii of curvature.
The size, shape, position and number of subsidiary electrode 26 is selected so as to maximize the coating precipitation factor, while minimizing the effect of corona discharge in the area of precipitation electrode 22 and/or so as to provide for controlled fiber orientation upon deposition.
According to one preferred embodiment of the present invention, subsidiary electrode 26 is positioned 5-70 mm away from precipitation electrode 22.
Preferably, such a distance is selected according to the following:
b=l2~iR(1-V2/Vl) (Eq.l) where (3 is a dimensionless constant named a fiber-charge accounting factor, which ranges between about 0.7 and about 0.9, R is the curvature-radius of precipitation electrode 22, Vl is the potential difference between dispenser 24 and precipitation electrode 22 and VZ is the potential difference between subsidiary electrode 26 and precipitation electrode 22.
Subsidiary electrode 26 may include a mechanism for moving it along a longitudinal axis of precipitation electrode 22. Such a mechanism may be in use when enhanced control over fiber orientation is required.
It will be appreciated that in an apparatus in which both dispenser 24 and subsidiary electrode 26 are capable of such longitudinal motion, such motion may be either independent or synchronized.
Subsidiary electrode 26 may also be tilted through an angle of 45-90 degrees with respect to the longitudinal axis of precipitation electrode 22.
Such tilting may be used to provide for controlled fiber orientation upon deposition, hence to control the radial strength of the manufactured shell;
specifically, large angles result in higher radial strength.
In addition to positioning, the shape and size of electrode 26 may also determine the quality of the shell formed by apparatus 20. Thus, electrode 26 may be fabricated in a variety of shapes each serving a specific purpose. Electrode shapes which can be used with apparatus 20 of the present invention include, but are not limited to, a plane, a cylinder, a torus a rod, a knife, an arc or a ring.
An apparatus 20 which includes a subsidiary electrode 26 of a cylindrical (Figure 4) or a flat shape (Figure 3) enables manufacturing intricate-profile products being at least partially with small radius of curvature, which radius may range between 0.025 millimeters and 5 millimeters. As can be seen in Figures 8-9 (further described in the Examples section), the coating of such structures is characterized by random-oriented (Figure 8) or even polar-oriented (Figure 9) fibers, as opposed to an axial coating which is typical for small curvature products manufactured via existing electrospinning methods as demonstrated in Figure 7 (further described in the Examples section).
Preferably, when a surface of large curvature is used as subsidiary electrode 26, as is the case above, the distance between subsidiary electrode 26 and precipitation electrode 22 can be determined as 8/x where x is a factor ranging between 1.8 and 2, and where 8 is as defined by Equation 1 above.
Thus, positioning and/or shape of electrode 26 determines fiber orientation in the polymer fiber shell formed.
The ability to control fiber orientation is important when fabricating vascular grafts in which a high radial strength and elasticity is important.
It will be appreciated that a polar oriented structure can generally be obtained also by wet spinning methods, however in wet spinning methods the fibers are thicker than those .used by electrospinning by at least an order of magnitude.
Control over fiber orientation is also advantageous when fabricating composite polymer fiber shells which are manufactured by sequential deposition of several different fiber materials.
Reference is now made to Figure 5, which illustrates an apparatus 20 which utilizes a linear (e.g., a rod, a knife, an arc or a ring) subsidiary electrode 26.
The effect of subsidiary electrode 26 of linear shape is based on the distortion it introduces to the electric field in an area adjacent to precipitation electrode 22. For maximum effect the diameter of subsidiary electrode 26 must be considerably smaller than that of precipitation electrode 22, yet large enough to avoid generation of a significant corona discharge. Fiber coating generated by apparatus 20 utilizing a linear subsidiary electrode 26 is illustrated by Figure 10 which is further described in the Examples section hereinunder.
Thus, the present invention provides an electrospinning apparatus in which the electric field is under substantial control, thereby providing either random or predetermined fibers orientation.
Although the use of at least one subsidiary electrode is presently preferred, field non-uniformities can also be at least partially overcome by providing a composite precipitation electrode.
As illustrated in Figure 6, precipitation electrode 34 of apparatus 30 having a dispenser 32 can be designed and configured so as to reduce non-uniformities in the electric field.
To overcome field non-uniformities, precipitation electrode 34 is fabricated from at least two layers of materials, an inner layer 36 made of electroconductive material and an outer layer 38 made of a material having high dielectric properties. Such a fabrication design results in a considerable increase of corona discharge threshold thus considerably reducing corona discharge from precipitation electrode 34.
Materials suitable for use with outer layer 38 of precipitation electrode 34, can be ceramic materials e.g., Titanium Nitride, Aluminum Oxide and the like, or polymer materials e.g., polyamide, polyacrylonitrile, polytetrafluoroethylene and the like. The thickness of outer layer 38 depends on the dielectric properties of the material from which it is made and can vary from less than one micron, in the case of, for example, a Titanium Nitride Layer, or tens of microns, in the case of, for example, polytetrafluoroethylene, polyamide or polyacrylonitrile layer. In addition to diminishing corona discharge this precipitation electrode configuration enables easier separation of formed structures therefrom. Thus; according to this configuration outer layer 38 of precipitation electrode 34 can also be configured for facilitating the removal of the final product from the mandrel.
Additional objects, advantages, and novel features of the present invention will become apparent to one ordinarily skilled in the art upon examination of the following' examples, which are not intended to be limiting. Additionally, each of the various embodiments and aspects of the present invention as delineated hereinabove and as claimed in the claims section below finds experimental support in the following examples.
EXAMPLES
Reference is now made to the following examples, which together with the above descriptions, illustrate the invention in a non limiting fashion.
Electrospinniszg Material A polycarbonate resin grade Caliper 2071 was purchased from Daw Chemical Co. This Polymer is characterized as having good fiber forming abilities and is convenient for electrospinning. Chloroform was used as solvent in all of the examples described hereinbelow.
5 Axial Covering Using Conventional Electrospinnisig Method Reference is now made to Figure 7, which is an example of non-randomized covering of thin mandrels via conventional electrospinning. A 3-mm cylindrical mandrel was covered by polycarbonate fiber using prior art electrospinning approaches. Figure 7 is 10 an electron microscope image of the final product, in which axial fiber orientation is well evident. Due to non-uniformities in the electric field, the fibers, while still in motion in the inter-electrode space, are oriented in conformity with the field configuration, and the obtained tubular structure exhibits axial orientation of fibers, and as such is characterized by axial, as 15 opposed to radial strength.
Random Covering Using Flat Subsidiary Electrode An apparatus constructed and operative in accordance with the 20 teachings of the present invention incorporating a flat subsidiary electrode positioned 20 millimeters from the mandrel and having the same potential as the mandrel was used to spin a polycarbonate tubular structure of a 3 mm radius. As is evident from Figure 8, the presence of a subsidiary electrode randomizes fibers orientation.
Polar-Oriented Covering Using Flat Subsidiary electrode An apparatus constructed and operative in accordance with the teachings of the present invention incorporating a flat subsidiary electrode positioned 9 millimeters from the mandrel and being at a potential difference of 5 kV from the mandrel was used to spin a polycarbonate tubular structure of a 3 mm radius.
As illustrated by Figure 9, reduction of equalizing electrode-mandrel distance results in polar-oriented covering. Thus, by keeping subsidiary electrode and mandrel within a relatively small distance, while providing a non-zero potential difference therebetween, leads to slow or no fiber charge dissipation and, as a result, the inter-electrode space becomes populated with fiber which are held statically in a stretched position, oriented perpendicular to mandrel symmetry axis. Once stretched, the fibers are gradually coiled around the rotating mandrel, generating a polar-oriented structure.
E~IlVIPLE 4 Predefined Oriented Coveri~ag UsifZg Linear Subsidiary electrode Figure 10 illustrates result obtained from an apparatus configuration which may be employed in order to obtain a predefined oriented structural fiber covering.
An apparatus which includes an elliptical subsidiary electrode and a dispenser both moving along the longitudinal axis of the mandrel in a reciprocating synchronous movement was used to coat a 3-mm cylindrical mandrel with polycarbonate fiber. The subsidiary electrode had a large diameter of 120 mm, a small diameter of 117.6 mm and a thickness of 1.2 mm. The subsidiary electrode was positioned 15 mm from the mandrel, at an 80 ° tilt with respect to the mandrel symmetry axis.
It is appreciated that certain features of the invention, which are, for clarity, described in the context of separate embodiments, may also be provided in combination in a single embodiment. Conversely, various features of the invention, which are, for brevity, described in the context of a single embodiment, may also be provided separately or in any suitable subcombination.
Although the invention has been described in conjunction with specific embodiments thereof, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art.
Accordingly, it is intended to embrace all such alternatives, modifications and variations that fall within the spirit and broad scope of the appended claims. All publications, patents and patent applications mentioned in this specification are herein incorporated in their entirety by reference into the specification, to the same extent as if each individual publication, patent or patent application was specifically and individually indicated to be incorporated herein by reference. In addition, citation or identification of any reference in this application shall not be construed as an admission that such reference is available as prior art to the present invention.
Claims (58)
1. An apparatus for manufacturing polymer fiber shell from liquefied polymer, the apparatus comprising:
(a) a precipitation electrode being for generating the polymer fiber shell thereupon;
(b) a dispenser, being at a first potential relative to said precipitation electrode so as to generate an electric field between said precipitation electrode and said dispenser, said dispenser being for:
(i) charging the liquefied polymer thereby providing a charged liquefied polymer; and (ii) dispensing said charged liquefied polymer in a direction of said precipitation electrode; and (c) a subsidiary electrode being at a second potential relative to said precipitation electrode, said subsidiary electrode being for modifying said electric field between said precipitation electrode and said dispenser.
(a) a precipitation electrode being for generating the polymer fiber shell thereupon;
(b) a dispenser, being at a first potential relative to said precipitation electrode so as to generate an electric field between said precipitation electrode and said dispenser, said dispenser being for:
(i) charging the liquefied polymer thereby providing a charged liquefied polymer; and (ii) dispensing said charged liquefied polymer in a direction of said precipitation electrode; and (c) a subsidiary electrode being at a second potential relative to said precipitation electrode, said subsidiary electrode being for modifying said electric field between said precipitation electrode and said dispenser.
2. The apparatus of claim 1, wherein said subsidiary electrode serves for reducing non-uniformities in said electric field between said precipitation electrode and said dispenser.
3. The apparatus of claim 1, wherein said subsidiary electrode serves for controlling fiber orientation of said polymer fiber shell generated upon said precipitation electrode.
4. The apparatus according to claim 1, wherein said dispenser comprises a mechanism for forming a jet of said charged liquefied polymer.
5. The apparatus according to claim 1, further comprising a bath for holding the liquefied polymer.
6. The apparatus according to claim 4, wherein said mechanism for forming a jet of said charged liquefied polymer includes a dispensing electrode.
7. The apparatus according to claim 1, wherein said dispenser is operative to move along a longitudinal axis of said precipitation electrode.
8. The apparatus according to claim 1, wherein said precipitation electrode includes at least one rotating mandrel.
9. The apparatus according to claim 8, wherein said rotating mandrel is a cylindrical mandrel.
10. The apparatus according to claim 9, wherein said cylindrical mandrel is of a diameter selected from a range of 0.1 to 20 millimeters.
11. The apparatus according to claim 8, wherein said rotating mandrel is an intricate-profile mandrel.
12. The apparatus according to claim 11, wherein said intricate-profile mandrel includes sharp structural elements.
13. The apparatus according to claim 1, wherein said precipitation electrode includes at least one structural element selected from the group consisting of a protrusion, an orifice, a groove, and a grind.
14. The apparatus according to claim 1, wherein said subsidiary electrode is of a shape selected from the group consisting of a plane, a cylinder, a torus and a wire.
15. The apparatus according to claim 1, wherein said subsidiary electrode is operative to move along a longitudinal axis of said precipitation electrode.
16. The apparatus according to claim 1, wherein said subsidiary electrode is tilted at angle with respect to a longitudinal axis of said precipitation electrode, said angle is ranging between 45 and 90 degrees.
17. The apparatus according to claim 1, wherein said subsidiary electrode is positioned at a distance of 5 - 70 millimeters from said precipitation electrode.
18. The apparatus according to claim 1, wherein said subsidiary electrode is positioned at a distance ~ from said precipitation electrode, ~
being equal to 12.beta.R(1-V2/V1), where .beta. is a constant ranging between about 0.7 and about 0.9, R is a curvature-radius of the polymer fiber shell formed on said precipitation electrode, V1 is said first potential and V2 is said second potential.
being equal to 12.beta.R(1-V2/V1), where .beta. is a constant ranging between about 0.7 and about 0.9, R is a curvature-radius of the polymer fiber shell formed on said precipitation electrode, V1 is said first potential and V2 is said second potential.
19. A method for forming a liquefied polymer into a non-woven polymer fiber shell, the method comprising:
(a) charging the liquefied polymer thereby producing a charged liquefied polymer;
(b) subjecting said charged liquefied polymer to a first electric field;
(c) dispensing said charged liquefied polymer within said first electric field in a direction of a precipitation electrode, said precipitation electrode being designed and configured for generating the polymer fiber shell thereupon;
(d) providing a second electric field being for modifying said first electric field; and (e) using said precipitation electrode to collect said charged liquefied polymer thereupon, thereby forming the non-woven polymer fiber shells.
(a) charging the liquefied polymer thereby producing a charged liquefied polymer;
(b) subjecting said charged liquefied polymer to a first electric field;
(c) dispensing said charged liquefied polymer within said first electric field in a direction of a precipitation electrode, said precipitation electrode being designed and configured for generating the polymer fiber shell thereupon;
(d) providing a second electric field being for modifying said first electric field; and (e) using said precipitation electrode to collect said charged liquefied polymer thereupon, thereby forming the non-woven polymer fiber shells.
20. The method according to claim 19, wherein said first electric field is defined between said precipitation electrode and a dispensing electrode being at a first potential relative to said precipitation electrode.
21. The method according to claim 20, wherein step (c) is effected by dispensing said charged liquefied polymer from said dispensing electrode.
22. The method according to claim 19, further comprising moving said dispensing electrode along a longitudinal axis of said precipitation electrode during step (c).
23. The method according to claim 19, wherein said precipitation electrode includes at least one rotating mandrel.
24. The method according to claim 23, wherein said rotating mandrel is a cylindrical mandrel.
25. The method according to claim 24, wherein said cylindrical mandrel is of a diameter selected from a range of 0.1 to 20 millimeters.
26. The method according to claim 23, wherein said rotating mandrel is an intricate-profile mandrel.
27. The method according to claim 26, wherein said intricate-profile mandrel includes sharp structural elements.
28. The method according to claim 25, wherein said precipitation electrode includes at least one structural element selected from the group consisting of a protrusion, an orifice, a groove, and a grind.
29. The method according to claim 20, wherein said second electric field is defined by a subsidiary electrode being at a second potential relative to said precipitation electrode.
30. The method according to claim 29, wherein said subsidiary electrode serves for reducing non-uniformities in said first electric field.
31. The method according to claim 19, wherein said subsidiary electrode serves for controlling fiber orientation of said polymer fiber shell generated upon said precipitation electrode.
32. The method according to claim 29, wherein said subsidiary electrode is of a shape selected from the group consisting of a plane, a cylinder, a torus and a wire.
33. The method according to claim 29, further comprising moving said subsidiary electrode along said precipitation electrode during step (e).
34. The method according to claim 29, further comprising tilting said subsidiary electrode at angle with respect to a longitudinal axis of said precipitation electrode, said angle ranging between 45 and 90 degrees.
35. The method according to claim 29, wherein said subsidiary electrode is positioned at a distance of 5 - 50 millimeters from said precipitation electrode.
36. The method according to claim 29, wherein said subsidiary electrode is positioned at a distance ~ from said precipitation electrode, ~
being equal to 12.beta.R(1-V2/V1), where .beta. is a constant ranging between about 0.7 and about 0.9, R is a curvature-radius of the polymer fiber shell formed on said precipitation electrode, V1 is said first potential and V2 is said second potential.
being equal to 12.beta.R(1-V2/V1), where .beta. is a constant ranging between about 0.7 and about 0.9, R is a curvature-radius of the polymer fiber shell formed on said precipitation electrode, V1 is said first potential and V2 is said second potential.
37. An apparatus for manufacturing a polymer fiber shell from liquefied polymer, the apparatus comprising:
(a) a dispenser, for:
(i) charging the liquefied polymer thereby providing a charged liquefied polymer; and (ii) dispensing said charged liquefied polymer; and (b) a precipitation electrode being at a potential relative to said dispenser thereby generating an electric field between said precipitation electrode and said dispenser, said precipitation electrode being for collecting said charged liquefied polymer drawn by said electric field, to thereby form the polymer fiber shell thereupon, wherein said precipitation electrode is designed so as to reduce non-uniformities in said electric field.
(a) a dispenser, for:
(i) charging the liquefied polymer thereby providing a charged liquefied polymer; and (ii) dispensing said charged liquefied polymer; and (b) a precipitation electrode being at a potential relative to said dispenser thereby generating an electric field between said precipitation electrode and said dispenser, said precipitation electrode being for collecting said charged liquefied polymer drawn by said electric field, to thereby form the polymer fiber shell thereupon, wherein said precipitation electrode is designed so as to reduce non-uniformities in said electric field.
38. The apparatus according to claim 37, wherein said dispenser comprises a mechanism for forming a jet of said charged liquefied polymer.
39. The apparatus according to claim 37, further comprising a bath for holding the liquefied polymer.
40. The apparatus according to claim 38, wherein said mechanism for forming a jet of said charged liquefied polymer includes a dispensing electrode.
41. The apparatus according to claim 37, wherein said precipitation electrode is formed from a combination of electroconductive and non-electroconductive materials.
42. The apparatus according to claim 41, wherein a surface of said precipitation electrode is formed from a predetermined pattern of said electroconductive and non-electroconductive materials.
43. The apparatus according to claim 37, wherein said precipitation electrode is formed from at least two layers.
44. The apparatus according to claim 43, wherein said at least two layers include an electroconductive layer and a partial electroconductive layer.
45. The apparatus according to claim 44, wherein said partial electroconductive layer is formed from a combination of an electroconductive material and at least one dielectric material.
46. The apparatus according to claim 45, wherein said dielectric material is selected from a group consisting of polyamide, polytetrafluoroethylene and polyacrylonitrile.
47. The apparatus according to claim 45, wherein said dielectric material is Titanium Nitride.
48. The apparatus according to claim 44, wherein said partially electroconductive layer, is of a thickness selected from a range of 0.1 to 90 microns.
49. The apparatus according to claim 37, wherein said precipitation electrode is of a diameter selected from a range of 0.1 to 20 millimeters.
50. The apparatus according to claim 37, wherein said precipitation electrode includes at least one rotating mandrel.
51. The apparatus according to claim 50, wherein said rotating mandrel is a cylindrical mandrel.
52. A tubular structure manufactured by the apparatus of claim 1.
53. A tubular structure manufactured by the method of claim 29.
54. A tubular structure manufactured by the apparatus of claim 37.
55. The apparatus of claim 1, wherein said subsidiary electrode serves to minimize a volume charge generated between said dispenser and said precipitation electrode.
56. The method according to claim 29, wherein said subsidiary electrode serves to minimize a volume charge generated between said precipitation electrode and said dispensing electrode.
57. The apparatus according to claim 1, wherein said dispenser and said subsidiary electrode are operative to move synchronically along a longitudinal axis of said precipitation electrode.
58. The method according to claim 29, further comprising synchronically moving both said dispensing electrode and said subsidiary electrode along said precipitation electrode.
Applications Claiming Priority (7)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US25632300P | 2000-12-19 | 2000-12-19 | |
US60/256,323 | 2000-12-19 | ||
US27695601P | 2001-03-20 | 2001-03-20 | |
US60/276,956 | 2001-03-20 | ||
US09/982,017 | 2001-10-19 | ||
US09/982,017 US20020084178A1 (en) | 2000-12-19 | 2001-10-19 | Method and apparatus for manufacturing polymer fiber shells via electrospinning |
PCT/IL2001/001168 WO2002049678A2 (en) | 2000-12-19 | 2001-12-17 | Method and apparatus for manufacturing polymer fiber shells via electrospinning |
Publications (1)
Publication Number | Publication Date |
---|---|
CA2432156A1 true CA2432156A1 (en) | 2002-06-27 |
Family
ID=27400942
Family Applications (3)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
CA002432159A Abandoned CA2432159A1 (en) | 2000-12-19 | 2001-12-17 | Medicated polymer-coated stent assembly |
CA2432164A Expired - Fee Related CA2432164C (en) | 2000-12-19 | 2001-12-17 | Improved vascular prosthesis and method for production thereof |
CA002432156A Abandoned CA2432156A1 (en) | 2000-12-19 | 2001-12-17 | Method and apparatus for manufacturing polymer fiber shells via electrospinning |
Family Applications Before (2)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
CA002432159A Abandoned CA2432159A1 (en) | 2000-12-19 | 2001-12-17 | Medicated polymer-coated stent assembly |
CA2432164A Expired - Fee Related CA2432164C (en) | 2000-12-19 | 2001-12-17 | Improved vascular prosthesis and method for production thereof |
Country Status (12)
Country | Link |
---|---|
US (5) | US20020084178A1 (en) |
EP (3) | EP1353606B1 (en) |
JP (3) | JP2004532665A (en) |
CN (3) | CN1599582A (en) |
AT (2) | ATE462371T1 (en) |
AU (4) | AU2002222494A8 (en) |
CA (3) | CA2432159A1 (en) |
DE (2) | DE60141710D1 (en) |
HK (1) | HK1080347A1 (en) |
IL (5) | IL156512A0 (en) |
MX (3) | MXPA03005552A (en) |
WO (3) | WO2002049535A2 (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN104713909A (en) * | 2015-04-10 | 2015-06-17 | 湖南农业大学 | Simple method for authenticating fluorine injury of plants |
Families Citing this family (285)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US8382821B2 (en) | 1998-12-03 | 2013-02-26 | Medinol Ltd. | Helical hybrid stent |
US20070219642A1 (en) * | 1998-12-03 | 2007-09-20 | Jacob Richter | Hybrid stent having a fiber or wire backbone |
US20040267349A1 (en) | 2003-06-27 | 2004-12-30 | Kobi Richter | Amorphous metal alloy medical devices |
US20020081732A1 (en) * | 2000-10-18 | 2002-06-27 | Bowlin Gary L. | Electroprocessing in drug delivery and cell encapsulation |
WO2002018441A2 (en) * | 2000-09-01 | 2002-03-07 | Virginia Commonwealth University Intellectual Property Foundation | Electroprocessed fibrin-based matrices and tissues |
US7615373B2 (en) * | 1999-02-25 | 2009-11-10 | Virginia Commonwealth University Intellectual Property Foundation | Electroprocessed collagen and tissue engineering |
US6743273B2 (en) * | 2000-09-05 | 2004-06-01 | Donaldson Company, Inc. | Polymer, polymer microfiber, polymer nanofiber and applications including filter structures |
US7270693B2 (en) * | 2000-09-05 | 2007-09-18 | Donaldson Company, Inc. | Polymer, polymer microfiber, polymer nanofiber and applications including filter structures |
US20070031607A1 (en) * | 2000-12-19 | 2007-02-08 | Alexander Dubson | Method and apparatus for coating medical implants |
US20020084178A1 (en) * | 2000-12-19 | 2002-07-04 | Nicast Corporation Ltd. | Method and apparatus for manufacturing polymer fiber shells via electrospinning |
RU2300543C2 (en) * | 2001-05-31 | 2007-06-10 | Дональдсон Компани, Инк. | Fine fiber compositions, methods for preparation thereof, and a method of manufacturing fine-fiber material |
WO2003087443A1 (en) * | 2002-04-11 | 2003-10-23 | Secant Medical, Inc. | Covering process using electrospinning of very small fibers |
JP5445649B2 (en) * | 2002-08-23 | 2014-03-19 | 独立行政法人国立循環器病研究センター | Stent |
GB0223870D0 (en) * | 2002-10-14 | 2002-11-20 | Cathnet Science Holding As | Stent assembly |
US6949916B2 (en) * | 2002-11-12 | 2005-09-27 | Power-One Limited | System and method for controlling a point-of-load regulator |
US20040098023A1 (en) * | 2002-11-15 | 2004-05-20 | Scimed Life Systems, Inc. | Embolic device made of nanofibers |
JP4047739B2 (en) * | 2003-02-04 | 2008-02-13 | 日本バイリーン株式会社 | Electrostatic spinning method and electrostatic spinning apparatus |
JP2004256974A (en) * | 2003-02-27 | 2004-09-16 | Japan Vilene Co Ltd | Method for electrospinning and device for electrospinning |
JP4047744B2 (en) * | 2003-02-27 | 2008-02-13 | 日本バイリーン株式会社 | Electrostatic spinning method and electrostatic spinning apparatus |
US7658747B2 (en) | 2003-03-12 | 2010-02-09 | Nmt Medical, Inc. | Medical device for manipulation of a medical implant |
JP4496360B2 (en) * | 2003-04-24 | 2010-07-07 | 国立大学法人九州大学 | Medical Polymer Nano / Microfiber |
US7452374B2 (en) * | 2003-04-24 | 2008-11-18 | Maquet Cardiovascular, Llc | AV grafts with rapid post-operative self-sealing capabilities |
JP4971580B2 (en) * | 2003-06-05 | 2012-07-11 | テルモ株式会社 | Stent and method for manufacturing stent |
US9039755B2 (en) | 2003-06-27 | 2015-05-26 | Medinol Ltd. | Helical hybrid stent |
US9155639B2 (en) | 2009-04-22 | 2015-10-13 | Medinol Ltd. | Helical hybrid stent |
FR2858543B1 (en) * | 2003-08-08 | 2006-02-03 | Assist Publ Hopitaux De Paris | AORTIC AND ANCILLARY RING FOR ITS INSTALLATION |
CZ294274B6 (en) * | 2003-09-08 | 2004-11-10 | Technická univerzita v Liberci | Process for producing nanofibers from polymeric solution by electrostatic spinning and apparatus for making the same |
EP1691856A2 (en) * | 2003-10-14 | 2006-08-23 | Cube Medical A/S | Medical device with electrospun nanofibers |
DE10350287A1 (en) | 2003-10-24 | 2005-05-25 | Deutsche Institute für Textil- und Faserforschung Stuttgart - Stiftung des öffentlichen Rechts | Cardiovascular implant, for use as a vascular or heart valve replacement, comprises a non-resorbable polymer formed as a microfiber fleece that allows colonization by a cells |
WO2005042813A1 (en) * | 2003-10-30 | 2005-05-12 | Clean Air Technology Corp. | Electrostatic spinning equipment and method of preparing nano fiber using the same |
WO2005055834A1 (en) * | 2003-11-20 | 2005-06-23 | Nmt Medical, Inc. | Device, with electrospun fabric, for a percutaneous transluminal procedure, and methods thereof |
WO2005064048A1 (en) * | 2003-12-30 | 2005-07-14 | Raisio Chemicals Korea Inc. | A method manufacturing nano-fibers with excellent fiber formation |
WO2005065578A2 (en) * | 2004-01-06 | 2005-07-21 | Nicast Ltd. | Vascular prosthesis with anastomotic member |
WO2005073441A1 (en) * | 2004-01-30 | 2005-08-11 | Raisio Chemicals Korea Inc. | A bottom-up electrospinning devices, and nanofibers prepared by using the same |
US8262694B2 (en) | 2004-01-30 | 2012-09-11 | W.L. Gore & Associates, Inc. | Devices, systems, and methods for closure of cardiac openings |
EP1718245A4 (en) | 2004-02-12 | 2008-03-19 | Univ Akron | Mechanically attached medical device coatings |
US7901447B2 (en) * | 2004-12-29 | 2011-03-08 | Boston Scientific Scimed, Inc. | Medical devices including a metallic film and at least one filament |
US20060142838A1 (en) * | 2004-12-29 | 2006-06-29 | Masoud Molaei | Medical devices including metallic films and methods for loading and deploying same |
US8998973B2 (en) * | 2004-03-02 | 2015-04-07 | Boston Scientific Scimed, Inc. | Medical devices including metallic films |
US20050197687A1 (en) * | 2004-03-02 | 2005-09-08 | Masoud Molaei | Medical devices including metallic films and methods for making same |
US8992592B2 (en) * | 2004-12-29 | 2015-03-31 | Boston Scientific Scimed, Inc. | Medical devices including metallic films |
US8632580B2 (en) * | 2004-12-29 | 2014-01-21 | Boston Scientific Scimed, Inc. | Flexible medical devices including metallic films |
US8591568B2 (en) * | 2004-03-02 | 2013-11-26 | Boston Scientific Scimed, Inc. | Medical devices including metallic films and methods for making same |
KR20060130740A (en) | 2004-03-16 | 2006-12-19 | 유니버시티 오브 델라웨어 | Active and adaptive photochromic fibers, textiles and membranes |
JP4312090B2 (en) * | 2004-03-18 | 2009-08-12 | 日本バイリーン株式会社 | Method for manufacturing fiber assembly and apparatus for manufacturing fiber assembly by electrostatic spinning |
WO2005095684A1 (en) * | 2004-03-25 | 2005-10-13 | Massachusetts Institute Of Technology | Production of submicron diameter fibers by two-fluid electrospinning process |
JP2005278993A (en) * | 2004-03-30 | 2005-10-13 | Terumo Corp | Stent for indwelling in living body, and production method of the same |
US7134857B2 (en) * | 2004-04-08 | 2006-11-14 | Research Triangle Institute | Electrospinning of fibers using a rotatable spray head |
US7762801B2 (en) | 2004-04-08 | 2010-07-27 | Research Triangle Institute | Electrospray/electrospinning apparatus and method |
US7297305B2 (en) * | 2004-04-08 | 2007-11-20 | Research Triangle Institute | Electrospinning in a controlled gaseous environment |
US7592277B2 (en) * | 2005-05-17 | 2009-09-22 | Research Triangle Institute | Nanofiber mats and production methods thereof |
NL1026076C2 (en) * | 2004-04-29 | 2005-11-01 | Univ Eindhoven Tech | Molded part manufactured by means of electro-spinning and a method for the manufacture thereof as well as the use of such a molded part. |
JP2007534389A (en) * | 2004-04-29 | 2007-11-29 | キューブ・メディカル・アクティーゼルスカブ | Balloon used for angiogenesis |
US20060012084A1 (en) * | 2004-07-13 | 2006-01-19 | Armantrout Jack E | Electroblowing web formation process |
US8313524B2 (en) * | 2004-08-31 | 2012-11-20 | C. R. Bard, Inc. | Self-sealing PTFE graft with kink resistance |
US9801982B2 (en) | 2004-09-28 | 2017-10-31 | Atrium Medical Corporation | Implantable barrier device |
WO2006036982A2 (en) | 2004-09-28 | 2006-04-06 | Atrium Medical Corporation | Drug delivery coating for use with a stent |
US9000040B2 (en) | 2004-09-28 | 2015-04-07 | Atrium Medical Corporation | Cross-linked fatty acid-based biomaterials |
US9012506B2 (en) | 2004-09-28 | 2015-04-21 | Atrium Medical Corporation | Cross-linked fatty acid-based biomaterials |
WO2006036969A2 (en) | 2004-09-28 | 2006-04-06 | Atrium Medical Corporation | Formation of barrier layer |
US20090202616A1 (en) * | 2004-09-29 | 2009-08-13 | National University Of Singapore | Composite, Method of Producing the Composite and Uses of the Same |
US7390760B1 (en) * | 2004-11-02 | 2008-06-24 | Kimberly-Clark Worldwide, Inc. | Composite nanofiber materials and methods for making same |
US20060094320A1 (en) * | 2004-11-02 | 2006-05-04 | Kimberly-Clark Worldwide, Inc. | Gradient nanofiber materials and methods for making same |
US8029563B2 (en) * | 2004-11-29 | 2011-10-04 | Gore Enterprise Holdings, Inc. | Implantable devices with reduced needle puncture site leakage |
US7922761B2 (en) * | 2005-01-25 | 2011-04-12 | Nicast Ltd. | Artificial vascular prosthesis |
US10328032B2 (en) * | 2005-03-04 | 2019-06-25 | Biosurfaces, Inc. | Nanofibrous materials as drug, protein, or genetic release vehicles |
US8574713B2 (en) * | 2005-03-10 | 2013-11-05 | Massachusetts Institute Of Technology | Superhydrophobic fibers and methods of preparation and use thereof |
US7737131B2 (en) * | 2005-03-31 | 2010-06-15 | University Of Delaware | Multifunctional and biologically active matrices from multicomponent polymeric solutions |
US8415325B2 (en) * | 2005-03-31 | 2013-04-09 | University Of Delaware | Cell-mediated delivery and targeted erosion of noncovalently crosslinked hydrogels |
US8367639B2 (en) | 2005-03-31 | 2013-02-05 | University Of Delaware | Hydrogels with covalent and noncovalent crosslinks |
US7732427B2 (en) * | 2005-03-31 | 2010-06-08 | University Of Delaware | Multifunctional and biologically active matrices from multicomponent polymeric solutions |
US8871237B2 (en) | 2005-04-04 | 2014-10-28 | Technion Research & Development Foundation Limited | Medical scaffold, methods of fabrication and using thereof |
US7854760B2 (en) * | 2005-05-16 | 2010-12-21 | Boston Scientific Scimed, Inc. | Medical devices including metallic films |
EP1885282A4 (en) * | 2005-05-17 | 2010-05-05 | Nicast Ltd | Electrically charged implantable medical device |
US8267993B2 (en) | 2005-06-09 | 2012-09-18 | Coroneo, Inc. | Expandable annuloplasty ring and associated ring holder |
JP2009501027A (en) * | 2005-06-17 | 2009-01-15 | シー・アール・バード・インコーポレイテツド | Vascular graft with kinking resistance after tightening |
GB2427382A (en) * | 2005-06-21 | 2006-12-27 | Univ Sheffield | Electrospinning of fibres |
CN100531685C (en) * | 2005-07-20 | 2009-08-26 | 同济大学 | Tissue engineering blood vessel and method of construction in vitro |
FR2898502B1 (en) * | 2006-03-16 | 2012-06-15 | Sofradim Production | THREE DIMENSIONAL PROTHETIC FABRIC WITH RESORBABLE DENSE FACE |
US20070036842A1 (en) * | 2005-08-15 | 2007-02-15 | Concordia Manufacturing Llc | Non-woven scaffold for tissue engineering |
US7582247B2 (en) * | 2005-08-17 | 2009-09-01 | E. I. Du Pont De Nemours And Company | Electroblowing fiber spinning process |
US7465159B2 (en) * | 2005-08-17 | 2008-12-16 | E.I. Du Pont De Nemours And Company | Fiber charging apparatus |
WO2007030302A2 (en) * | 2005-09-01 | 2007-03-15 | Prescient Medical, Inc. | Drugs coated on a device to treat vulnerable plaque |
EP1929074A4 (en) * | 2005-09-26 | 2009-09-02 | Hak-Yong Kim | Conjugate electrospinning devices, conjugate nonwoven and filament comprising nanofibers prepared by using the same |
US8574627B2 (en) | 2006-11-06 | 2013-11-05 | Atrium Medical Corporation | Coated surgical mesh |
US9427423B2 (en) | 2009-03-10 | 2016-08-30 | Atrium Medical Corporation | Fatty-acid based particles |
US9278161B2 (en) | 2005-09-28 | 2016-03-08 | Atrium Medical Corporation | Tissue-separating fatty acid adhesion barrier |
CA2626030A1 (en) | 2005-10-15 | 2007-04-26 | Atrium Medical Corporation | Hydrophobic cross-linked gels for bioabsorbable drug carrier coatings |
US20070173787A1 (en) * | 2005-11-01 | 2007-07-26 | Huang Mark C T | Thin-film nitinol based drug eluting stent |
US8636794B2 (en) | 2005-11-09 | 2014-01-28 | C. R. Bard, Inc. | Grafts and stent grafts having a radiopaque marker |
CA2631419A1 (en) * | 2005-11-28 | 2007-05-31 | University Of Delaware | Method of producing polyolefin microfibers by solution electrospinning and fibers produced |
EP1957695B1 (en) * | 2005-12-07 | 2011-02-09 | Ramot at Tel-Aviv University Ltd. | Drug-delivering composite structures |
US20070155273A1 (en) * | 2005-12-16 | 2007-07-05 | Cornell Research Foundation, Inc. | Non-woven fabric for biomedical application based on poly(ester-amide)s |
US20070148365A1 (en) * | 2005-12-28 | 2007-06-28 | Knox David E | Process and apparatus for coating paper |
JP4778797B2 (en) * | 2006-01-25 | 2011-09-21 | 株式会社Espinex | Nanofiber |
US20070269481A1 (en) * | 2006-01-27 | 2007-11-22 | The Regents Of The University Of California | Biomimetic Scaffolds |
US20080220042A1 (en) * | 2006-01-27 | 2008-09-11 | The Regents Of The University Of California | Biomolecule-linked biomimetic scaffolds |
US20070203564A1 (en) * | 2006-02-28 | 2007-08-30 | Boston Scientific Scimed, Inc. | Biodegradable implants having accelerated biodegradation properties in vivo |
US7737060B2 (en) * | 2006-03-31 | 2010-06-15 | Boston Scientific Scimed, Inc. | Medical devices containing multi-component fibers |
WO2008020326A2 (en) * | 2006-04-07 | 2008-02-21 | Victor Barinov | Controlled electrospinning of fibers |
US7689291B2 (en) * | 2006-05-01 | 2010-03-30 | Cardiac Pacemakers, Inc. | Lead with fibrous matrix coating and methods related thereto |
JP2008011942A (en) * | 2006-07-03 | 2008-01-24 | Univ Kansai Medical | Medical tube |
CN101484619A (en) * | 2006-07-05 | 2009-07-15 | 松下电器产业株式会社 | Method and apparatus for producing nanofiber and polymeric web |
US9198749B2 (en) | 2006-10-12 | 2015-12-01 | C. R. Bard, Inc. | Vascular grafts with multiple channels and methods for making |
US9492596B2 (en) | 2006-11-06 | 2016-11-15 | Atrium Medical Corporation | Barrier layer with underlying medical device and one or more reinforcing support structures |
US9622888B2 (en) | 2006-11-16 | 2017-04-18 | W. L. Gore & Associates, Inc. | Stent having flexibly connected adjacent stent elements |
JP4809203B2 (en) * | 2006-12-13 | 2011-11-09 | パナソニック株式会社 | Nonwoven fabric manufacturing apparatus and nonwoven fabric manufacturing method |
TW200848561A (en) * | 2006-12-22 | 2008-12-16 | Body Organ Biomedical Corp | Device for manufacturing fibrils |
ATE481435T1 (en) * | 2007-01-12 | 2010-10-15 | Dow Corning | COMPOSITION CONTAINING SILICONE |
EP2478924A1 (en) | 2007-02-01 | 2012-07-25 | Technion Research & Development Foundation | Albumin fibers and fabrics and methods of generating and using same |
US20080208325A1 (en) * | 2007-02-27 | 2008-08-28 | Boston Scientific Scimed, Inc. | Medical articles for long term implantation |
JP2008253297A (en) * | 2007-03-30 | 2008-10-23 | Univ Kansai Medical | Medical tube |
US20090042029A1 (en) * | 2007-04-13 | 2009-02-12 | Drexel University | Polyamide nanofibers and methods thereof |
WO2008151117A1 (en) * | 2007-06-01 | 2008-12-11 | United States Of America As Represented By The Administrator Of The National Aeronautics And Space Administration | Method and system for aligning fibers during electrospinning |
US20100331957A1 (en) * | 2007-06-11 | 2010-12-30 | Nanovasc, Inc. | Implantable medical device |
AU2008261691A1 (en) * | 2007-06-11 | 2008-12-18 | Nanovasc, Inc. | Stents |
US20100070020A1 (en) | 2008-06-11 | 2010-03-18 | Nanovasc, Inc. | Implantable Medical Device |
CA2692143C (en) * | 2007-06-19 | 2015-07-07 | Abdellah Ajji | Non-woven mat and method of producing same |
US20090004455A1 (en) * | 2007-06-27 | 2009-01-01 | Philippe Gravagna | Reinforced composite implant |
JP5142607B2 (en) * | 2007-07-03 | 2013-02-13 | 兵庫県 | Cover stent and manufacturing method thereof |
US20090030504A1 (en) * | 2007-07-27 | 2009-01-29 | Boston Scientific Scimed, Inc. | Medical devices comprising porous inorganic fibers for the release of therapeutic agents |
RU2489993C2 (en) * | 2007-10-10 | 2013-08-20 | Уэйк Форест Юниверсити Хелс Сайенсиз | Device and method of treating spinal cord tissue |
BRPI0817372A2 (en) * | 2007-11-09 | 2017-06-13 | Du Pont | "process for removing spinning solvent" |
US9308068B2 (en) | 2007-12-03 | 2016-04-12 | Sofradim Production | Implant for parastomal hernia |
US8926688B2 (en) | 2008-01-11 | 2015-01-06 | W. L. Gore & Assoc. Inc. | Stent having adjacent elements connected by flexible webs |
WO2009117356A1 (en) * | 2008-03-17 | 2009-09-24 | The Board Of Regents Of The University Of Taxes System | Methods and apparatuses for making superfine fibers |
US8252048B2 (en) | 2008-03-19 | 2012-08-28 | Boston Scientific Scimed, Inc. | Drug eluting stent and method of making the same |
WO2009150644A2 (en) * | 2008-06-10 | 2009-12-17 | Technion Research & Development Foundation Ltd. | Nonwoven structure and method of fabricating the same |
US9242026B2 (en) * | 2008-06-27 | 2016-01-26 | Sofradim Production | Biosynthetic implant for soft tissue repair |
US8076529B2 (en) | 2008-09-26 | 2011-12-13 | Abbott Cardiovascular Systems, Inc. | Expandable member formed of a fibrous matrix for intraluminal drug delivery |
US8226603B2 (en) * | 2008-09-25 | 2012-07-24 | Abbott Cardiovascular Systems Inc. | Expandable member having a covering formed of a fibrous matrix for intraluminal drug delivery |
US8049061B2 (en) * | 2008-09-25 | 2011-11-01 | Abbott Cardiovascular Systems, Inc. | Expandable member formed of a fibrous matrix having hydrogel polymer for intraluminal drug delivery |
US8500687B2 (en) | 2008-09-25 | 2013-08-06 | Abbott Cardiovascular Systems Inc. | Stent delivery system having a fibrous matrix covering with improved stent retention |
EP2962704A1 (en) | 2008-10-07 | 2016-01-06 | Nanonerve, Inc. | Multilayer fibrous polymer scaffolds, methods of production and methods of use |
AU2009304600B2 (en) * | 2008-10-17 | 2016-05-12 | Newtech Textile Technology Development (Shanghai) Co., Ltd. | Electrostatic spinning assembly |
US9427304B2 (en) * | 2008-10-27 | 2016-08-30 | St. Jude Medical, Cardiology Division, Inc. | Multi-layer device with gap for treating a target site and associated method |
PL2384375T3 (en) | 2009-01-16 | 2017-12-29 | Zeus Industrial Products, Inc. | Electrospinning of ptfe with high viscosity materials |
US20130268062A1 (en) * | 2012-04-05 | 2013-10-10 | Zeus Industrial Products, Inc. | Composite prosthetic devices |
US8425810B2 (en) | 2009-02-05 | 2013-04-23 | Panasonic Corporation | Nanofiber production device and nanofiber production method |
CN102405061B (en) | 2009-03-19 | 2015-12-09 | Emd密理博公司 | Nanofiber filter media is used to remove microorganism from fluid sample |
US8346374B2 (en) * | 2009-07-09 | 2013-01-01 | Cardiac Pacemakers, Inc. | Laminate distal lead seal with tissue ingrowth feature |
JP5456892B2 (en) | 2009-08-07 | 2014-04-02 | ゼウス インダストリアル プロダクツ インコーポレイテッド | Multilayer composite |
US20110038910A1 (en) | 2009-08-11 | 2011-02-17 | Atrium Medical Corporation | Anti-infective antimicrobial-containing biomaterials |
FR2949688B1 (en) | 2009-09-04 | 2012-08-24 | Sofradim Production | FABRIC WITH PICOTS COATED WITH A BIORESORBABLE MICROPOROUS LAYER |
DE102009047925A1 (en) | 2009-10-01 | 2011-06-16 | Qualimed Innovative Medizinprodukte Gmbh | Endoluminal tubular stent graft |
EP2314739A1 (en) * | 2009-10-22 | 2011-04-27 | Gyeong-Man Kim | Anti-migration casing for transponders |
US9005604B2 (en) | 2009-12-15 | 2015-04-14 | The United States Of America As Represented By The Administrator Of The National Aeronautics And Space Administration | Aligned and electrospun piezoelectric polymer fiber assembly and scaffold |
EP2519188A4 (en) * | 2009-12-31 | 2017-03-22 | Neograft Technologies, Inc. | Graft devices and methods of fabrication |
CZ303024B6 (en) * | 2010-03-05 | 2012-02-29 | Šafár@Václav | Process for producing nanofibers by electrostatic spinning of polymeric solution and apparatus for making the same |
AU2011257663A1 (en) * | 2010-05-27 | 2012-10-04 | Hemoteq Ag | Coating of endoprostheses with a coating consisting of a tight mesh of polymer fibres |
EP3508641B1 (en) | 2010-06-17 | 2020-08-05 | Washington University | Biomedical patches with aligned fibers |
US10322213B2 (en) | 2010-07-16 | 2019-06-18 | Atrium Medical Corporation | Compositions and methods for altering the rate of hydrolysis of cured oil-based materials |
ES2774949T3 (en) | 2010-08-10 | 2020-07-23 | Emd Millipore Corp | Retrovirus removal method |
JP2013520584A (en) | 2010-10-14 | 2013-06-06 | ゼウス インダストリアル プロダクツ インコーポレイテッド | Antibacterial substrate |
US9168231B2 (en) | 2010-12-05 | 2015-10-27 | Nanonerve, Inc. | Fibrous polymer scaffolds having diametrically patterned polymer fibers |
KR101187212B1 (en) | 2010-12-30 | 2012-10-02 | 주식회사 엠아이텍 | Method for manufacturing drug eluting stent for benign biliary structure using electrospinning |
RU2581871C2 (en) * | 2011-01-28 | 2016-04-20 | Мерит Медикал Системз, Инк. | Electrospun ptfe coated stent and method of use |
US8778240B2 (en) | 2011-02-07 | 2014-07-15 | Fiberio Technology Corporation | Split fiber producing devices and methods for the production of microfibers and nanofibers |
DE102011012501A1 (en) * | 2011-02-25 | 2012-08-30 | Phenox Gmbh | Implant with fiber fleece |
FR2972626B1 (en) | 2011-03-16 | 2014-04-11 | Sofradim Production | PROSTHETIC COMPRISING A THREE-DIMENSIONAL KNIT AND ADJUSTED |
US10227568B2 (en) | 2011-03-22 | 2019-03-12 | Nanofiber Solutions, Llc | Fiber scaffolds for use in esophageal prostheses |
US11154821B2 (en) | 2011-04-01 | 2021-10-26 | Emd Millipore Corporation | Nanofiber containing composite membrane structures |
CZ303380B6 (en) | 2011-06-27 | 2012-08-22 | Contipro Biotech S.R.O. | Process for producing materials exhibiting anisotropic properties and composed of nanofibers or microfibers and apparatus for making the same |
FR2977789B1 (en) | 2011-07-13 | 2013-07-19 | Sofradim Production | PROSTHETIC FOR UMBILIC HERNIA |
FR2977790B1 (en) | 2011-07-13 | 2013-07-19 | Sofradim Production | PROSTHETIC FOR UMBILIC HERNIA |
US9163333B2 (en) | 2011-07-15 | 2015-10-20 | Cook Medical Technologies Llc | Method for electrospinning a graft layer |
WO2013011511A1 (en) | 2011-07-18 | 2013-01-24 | Mor Research Applications Ltd. | A device for adjusting the intraocular pressure |
CN102358959B (en) * | 2011-08-16 | 2013-11-06 | 中山大学 | Method and device for preparing electrospinning fiber bracket with three-dimensional structure |
CN102973339A (en) * | 2011-09-05 | 2013-03-20 | 上海市第十人民医院 | Cardia stent with drug coating |
CN102973989A (en) * | 2011-09-05 | 2013-03-20 | 上海市第十人民医院 | Method for preparing surface fiber membrane of cardia stent |
CN102973340A (en) * | 2011-09-05 | 2013-03-20 | 上海市第十人民医院 | Biodegradable cardia support |
EP2760494B1 (en) | 2011-09-30 | 2017-04-19 | Sofradim Production | Reversible stiffening of light weight mesh |
US10239262B2 (en) | 2011-11-21 | 2019-03-26 | Nanofiber Solutions, Llc | Fiber scaffolds for use in tracheal prostheses |
DE102012008656A1 (en) * | 2011-12-29 | 2013-07-04 | Nonwotecc Medical Gmbh | Structure with fibers glued together in places |
FR2985170B1 (en) | 2011-12-29 | 2014-01-24 | Sofradim Production | PROSTHESIS FOR INGUINAL HERNIA |
FR2985271B1 (en) | 2011-12-29 | 2014-01-24 | Sofradim Production | KNITTED PICOTS |
WO2013106822A1 (en) | 2012-01-12 | 2013-07-18 | Johnson Jed K | Nanofiber scaffolds for biological structures |
WO2013109528A1 (en) | 2012-01-16 | 2013-07-25 | Merit Medical Systems, Inc. | Rotational spun material covered medical appliances and methods of manufacture |
CA2863980A1 (en) * | 2012-02-14 | 2013-08-22 | Neograft Technologies, Inc. | Kink resistant graft devices and related systems and methods |
PL231639B1 (en) | 2012-04-17 | 2019-03-29 | Politechnika Lodzka | Medical material for the reconstruction of blood vessels, a method for producing the medical material and medical material applied to the reconstruction of blood vessels |
US9867880B2 (en) | 2012-06-13 | 2018-01-16 | Atrium Medical Corporation | Cured oil-hydrogel biomaterial compositions for controlled drug delivery |
FR2994185B1 (en) | 2012-08-02 | 2015-07-31 | Sofradim Production | PROCESS FOR THE PREPARATION OF A POROUS CHITOSAN LAYER |
EP2887994B1 (en) | 2012-08-24 | 2019-02-20 | Boston Scientific Corporation | Device for improving brachytherapy |
CN102784015B (en) * | 2012-08-30 | 2015-06-03 | 广州迈普再生医学科技有限公司 | Artificial blood vessel loaded with pseudo-ginseng medicines, and preparation method and application for artificial blood vessel |
US20140081386A1 (en) * | 2012-09-14 | 2014-03-20 | Cook Medical Technologies Llc | Endoluminal prosthesis |
US11541154B2 (en) | 2012-09-19 | 2023-01-03 | Merit Medical Systems, Inc. | Electrospun material covered medical appliances and methods of manufacture |
EP3824853B1 (en) | 2012-09-21 | 2023-07-26 | Washington University | Biomedical patches with spatially arranged fibers |
US9198999B2 (en) | 2012-09-21 | 2015-12-01 | Merit Medical Systems, Inc. | Drug-eluting rotational spun coatings and methods of use |
FR2995779B1 (en) | 2012-09-25 | 2015-09-25 | Sofradim Production | PROSTHETIC COMPRISING A TREILLIS AND A MEANS OF CONSOLIDATION |
FR2995778B1 (en) | 2012-09-25 | 2015-06-26 | Sofradim Production | ABDOMINAL WALL REINFORCING PROSTHESIS AND METHOD FOR MANUFACTURING THE SAME |
FR2995788B1 (en) | 2012-09-25 | 2014-09-26 | Sofradim Production | HEMOSTATIC PATCH AND PREPARATION METHOD |
AU2013322268B2 (en) | 2012-09-28 | 2017-08-31 | Sofradim Production | Packaging for a hernia repair device |
US10582998B1 (en) * | 2012-10-17 | 2020-03-10 | Medshape, Inc. | Shape memory polymer fabrics |
US9091007B2 (en) * | 2012-12-10 | 2015-07-28 | Taipei Medical University | Electrospinning apparatus with a sideway motion device and a method of using the same |
US8992817B2 (en) * | 2012-12-10 | 2015-03-31 | Abbott Cardiovascular Systems, Inc. | Process of making a medical balloon |
US10154918B2 (en) * | 2012-12-28 | 2018-12-18 | Cook Medical Technologies Llc | Endoluminal prosthesis with fiber matrix |
WO2014159399A1 (en) | 2013-03-13 | 2014-10-02 | Merit Medical Systems, Inc. | Methods, systems, and apparatuses for manufacturing rotational spun appliances |
US10799617B2 (en) | 2013-03-13 | 2020-10-13 | Merit Medical Systems, Inc. | Serially deposited fiber materials and associated devices and methods |
EP3950019A1 (en) | 2013-03-15 | 2022-02-09 | Nanofiber Solutions, LLC | Biocompatible fiber textiles for implantation |
US10660645B2 (en) | 2013-03-15 | 2020-05-26 | Embo Medical Limited | Embolization systems |
US10675039B2 (en) | 2013-03-15 | 2020-06-09 | Embo Medical Limited | Embolisation systems |
NZ751703A (en) | 2013-03-15 | 2019-12-20 | Embo Medical Ltd | Embolisation systems |
FR3006581B1 (en) | 2013-06-07 | 2016-07-22 | Sofradim Production | PROSTHESIS BASED ON TEXTILE FOR LAPAROSCOPIC PATHWAY |
FR3006578B1 (en) | 2013-06-07 | 2015-05-29 | Sofradim Production | PROSTHESIS BASED ON TEXTILE FOR LAPAROSCOPIC PATHWAY |
CN103432631B (en) * | 2013-06-26 | 2014-12-31 | 上海大学 | Novel biodegradable vascular stent preparation method |
CN103418023B (en) * | 2013-07-29 | 2014-09-03 | 大连医科大学 | Multilayer composite hemostatic material and preparation method thereof |
EP3049121B1 (en) | 2013-09-25 | 2021-12-29 | Nanofiber Solutions, LLC | Fiber scaffolds for use creating implantable structures |
JP2015068986A (en) * | 2013-09-27 | 2015-04-13 | キヤノン株式会社 | Manufacturing method of conductive member for electrophotography |
KR101501383B1 (en) * | 2013-10-30 | 2015-03-10 | 가톨릭대학교 산학협력단 | Nanofiber scaffold with an aligned structure and method thereof |
CA2931151C (en) * | 2013-11-20 | 2022-02-15 | Ryan Joaquin GERAKOPULOS | Method and system for forming composites |
US9814560B2 (en) | 2013-12-05 | 2017-11-14 | W. L. Gore & Associates, Inc. | Tapered implantable device and methods for making such devices |
CA2935128A1 (en) * | 2013-12-27 | 2015-07-02 | Neograft Technologies, Inc. | Artificial graft devices and related systems and methods |
JP2017506921A (en) * | 2014-02-21 | 2017-03-16 | ヒーリオニクス・コーポレイションHealionics Corporation | Vascular graft and method for maintaining its patency |
US9675361B2 (en) | 2014-02-28 | 2017-06-13 | Cook Medical Technologies Llc | Coil occlusion device |
EP3000489B1 (en) | 2014-09-24 | 2017-04-05 | Sofradim Production | Method for preparing an anti-adhesion barrier film |
EP3000432B1 (en) | 2014-09-29 | 2022-05-04 | Sofradim Production | Textile-based prosthesis for treatment of inguinal hernia |
EP3000433B1 (en) | 2014-09-29 | 2022-09-21 | Sofradim Production | Device for introducing a prosthesis for hernia treatment into an incision and flexible textile based prosthesis |
CN104383606B (en) * | 2014-10-27 | 2016-02-17 | 北京航空航天大学 | A kind of high-strength high-elasticity intravascular stent and preparation method thereof |
US10299948B2 (en) | 2014-11-26 | 2019-05-28 | W. L. Gore & Associates, Inc. | Balloon expandable endoprosthesis |
EP3029189B1 (en) | 2014-12-05 | 2021-08-11 | Sofradim Production | Prosthetic porous knit, method of making same and hernia prosthesis |
US20160175082A1 (en) * | 2014-12-23 | 2016-06-23 | Novus Scientific Ab | Resorbable medical mesh implant for repair or prevention of parastomal hernia |
EP3059255B1 (en) | 2015-02-17 | 2020-05-13 | Sofradim Production | Method for preparing a chitosan-based matrix comprising a fiber reinforcement member |
JP6777642B2 (en) | 2015-02-26 | 2020-10-28 | メリット・メディカル・システムズ・インコーポレイテッドMerit Medical Systems,Inc. | Layered medical devices and methods |
US10583004B2 (en) | 2015-02-27 | 2020-03-10 | University of Pittsburgh — Of the Commonwealth System of Higher Education | Retrievable self-expanding non-thrombogenic low-profile percutaneous atrioventricular valve prosthesis |
JP6974916B2 (en) * | 2015-02-27 | 2021-12-01 | ユニバーシティ オブ ピッツバーグ − オブ ザ コモンウェルス システム オブ ハイヤー エデュケイション | Dual component mandrel for electrospun stentless fabrication of multi-valve valve |
FR3033494B1 (en) * | 2015-03-10 | 2017-03-24 | Carmat | TISSUE STENT AND METHOD FOR PRODUCING THE SAME |
CN107530639B (en) | 2015-04-17 | 2021-02-09 | Emd密理博公司 | Method for purifying target biological material in sample using nanofiber ultrafiltration membrane operating in tangential flow filtration mode |
EP3085337B1 (en) | 2015-04-24 | 2022-09-14 | Sofradim Production | Prosthesis for supporting a breast structure |
US10166315B2 (en) | 2015-05-04 | 2019-01-01 | Nanofiber Solutions, Inc. | Chitosan-enhanced electrospun fiber compositions |
US10357385B2 (en) | 2015-06-05 | 2019-07-23 | W. L. Gore & Associates, Inc. | Low bleed implantable prosthesis with a taper |
MX366842B (en) | 2015-06-08 | 2019-07-26 | Corneat Vision Ltd | Keratoprosthesis and uses thereof. |
ES2676072T3 (en) | 2015-06-19 | 2018-07-16 | Sofradim Production | Synthetic prosthesis comprising a knitted fabric and a non-porous film and method of forming it |
CN105113029A (en) * | 2015-09-23 | 2015-12-02 | 厦门大学 | Linear nozzle for electrostatic spinning |
CN108136078B (en) * | 2015-10-01 | 2021-10-12 | 谢尔蒂斯股份公司 | Method for electrospinning coating and laminating endoluminal prostheses |
WO2017070147A1 (en) | 2015-10-23 | 2017-04-27 | Boston Scientific Scimed, Inc. | Radioactive stents |
EP3370788A4 (en) | 2015-11-02 | 2019-07-31 | Nanofiber Solutions, LLC | Electrospun fibers having contrast agents and methods of making the same |
CN108778703A (en) * | 2016-01-08 | 2018-11-09 | 克拉考公司 | The use of microfibre and/or nanofiber in clothes and footwear |
EP3195830B1 (en) | 2016-01-25 | 2020-11-18 | Sofradim Production | Prosthesis for hernia repair |
WO2017156530A1 (en) * | 2016-03-11 | 2017-09-14 | The Johns Hopkins University | Partially degradable stents for controlled reduction of intraocular pressure |
KR101795923B1 (en) * | 2016-04-15 | 2017-11-10 | 연세대학교 산학협력단 | Stent for releasing nano-particle including biodegradable polymer, hydrophilic drug and hydrophobic drug |
US10632228B2 (en) | 2016-05-12 | 2020-04-28 | Acera Surgical, Inc. | Tissue substitute materials and methods for tissue repair |
US10568752B2 (en) | 2016-05-25 | 2020-02-25 | W. L. Gore & Associates, Inc. | Controlled endoprosthesis balloon expansion |
CN106319647A (en) * | 2016-10-21 | 2017-01-11 | 上海工程技术大学 | Method for preparing nanofiber aggregate and pretreatment device |
EP3312325B1 (en) | 2016-10-21 | 2021-09-22 | Sofradim Production | Method for forming a mesh having a barbed suture attached thereto and the mesh thus obtained |
WO2018081554A1 (en) * | 2016-10-27 | 2018-05-03 | North Carolina State University | 3d printing of fibrous structures |
US10898608B2 (en) | 2017-02-02 | 2021-01-26 | Nanofiber Solutions, Llc | Methods of improving bone-soft tissue healing using electrospun fibers |
US10368991B2 (en) * | 2017-02-06 | 2019-08-06 | C. R. Bard, Inc. | Device and associated percutaneous minimally invasive method for creating a venous valve |
EP3398554A1 (en) | 2017-05-02 | 2018-11-07 | Sofradim Production | Prosthesis for inguinal hernia repair |
GB201708025D0 (en) * | 2017-05-18 | 2017-07-05 | Clearstream Tech Ltd | A laminate membrane, an implant comprising the laminate membrane and a method of manufacturing the same |
TW201904527A (en) * | 2017-06-23 | 2019-02-01 | 鴻海精密工業股份有限公司 | Artificial blood vessel and method for making the same |
EP3427764A1 (en) | 2017-07-12 | 2019-01-16 | Université de Technologie de Compiègne | Fibrous polymer material comprising fibroin and polymer scaffolds comprising thereof |
EP3679181A4 (en) | 2017-09-08 | 2021-05-12 | The Board of Regents of The University of Texas System | Mechanoluminescence polymer doped fabrics and methods |
NL2019763B1 (en) * | 2017-10-19 | 2019-04-29 | Innovative Mechanical Engineering Tech B V | Electro hydrodynamic production method and system |
US20200337837A1 (en) * | 2017-10-30 | 2020-10-29 | Endoluminal Sciences Pty Ltd. | Expandable sealing skirt technology for leak-proof endovascular prostheses |
US11174570B2 (en) | 2018-02-05 | 2021-11-16 | Fermi Research Alliance, Llc | Methods and systems for electrospinning using low power voltage converter |
GB2573092A (en) * | 2018-03-02 | 2019-10-30 | The Electrospinning Company Ltd | Porous scaffold for the delivery of therapeutic agents |
CN110512292B (en) * | 2018-05-21 | 2023-02-17 | 武汉纺织大学 | Radial electrospinning nozzle based on rectangular blades |
CZ309078B6 (en) | 2018-05-28 | 2022-01-19 | Contipro A.S. | Device and method of producing nano- and / or microfibrous layers with increased thickness uniformity |
CN108939267B (en) * | 2018-05-28 | 2021-04-16 | 苏州大学 | Controlled drug release device and method |
MX2020013230A (en) * | 2018-06-05 | 2021-02-22 | Corneat Vision Ltd | A synthetic ophthalmic graft patch. |
CN109248340B (en) * | 2018-09-18 | 2021-04-23 | 武汉纺织大学 | Preparation method of fiber-based artificial blood vessel |
EP3653171A1 (en) | 2018-11-16 | 2020-05-20 | Sofradim Production | Implants suitable for soft tissue repair |
TW202031958A (en) * | 2018-12-05 | 2020-09-01 | 奧地利商蘭仁股份有限公司 | Method and device for producing tubular cellulosic spunbonded nonwoven fabrics |
DE102018131269B4 (en) | 2018-12-07 | 2021-08-05 | Acandis Gmbh | Medical device for insertion into a hollow body organ and manufacturing process |
WO2020123619A1 (en) | 2018-12-11 | 2020-06-18 | Nanofiber Solutions, Llc | Methods of treating chronic wounds using electrospun fibers |
EP3924031A4 (en) * | 2019-02-14 | 2022-11-23 | Technion Research & Development Foundation Limited | Composition, drug delivery device and method for local delivery of an active agent |
US11427937B2 (en) | 2019-02-20 | 2022-08-30 | The Board Of Regents Of The University Of Texas System | Handheld/portable apparatus for the production of microfibers, submicron fibers and nanofibers |
CN110067080B (en) * | 2019-03-07 | 2021-05-25 | 江苏大学 | Janus infrared radiation film for human body heat preservation and preparation method thereof |
CN109908401A (en) * | 2019-03-11 | 2019-06-21 | 武汉杨森生物技术有限公司 | A kind of production method of artificial blood vessel and products thereof for promoting endothelial cell to seek connections with |
CN110215540B (en) * | 2019-04-09 | 2021-07-27 | 盐城工业职业技术学院 | Silk fibroin/polymer based tubular stent with three-dimensional ordered and disordered double-network structure and preparation and use methods thereof |
EP3958787A1 (en) | 2019-04-25 | 2022-03-02 | Corneat Vision Ltd. | Keratoprosthesis devices and kits and surgical methods of their use |
EP3976864A4 (en) * | 2019-05-30 | 2023-09-06 | Skinner, Jack, L. | Device for polymer materials fabrication using gas flow and electrostatic fields |
CN110141760B (en) * | 2019-06-05 | 2021-10-08 | 山东百多安医疗器械股份有限公司 | Centrum forming expansion balloon with drug loaded on surface and preparation method thereof |
DE102019121562B4 (en) | 2019-08-09 | 2024-01-11 | Acandis Gmbh | Medical device for treating aneurysms |
DE102019121559A1 (en) * | 2019-08-09 | 2021-02-11 | Acandis Gmbh | Medical device for insertion into a hollow body organ and method for producing a medical device |
CA3146072C (en) | 2019-08-12 | 2024-01-02 | Gilad LITVIN | Synthetic gingival patch graft comprising micropores |
JPWO2021044858A1 (en) * | 2019-09-04 | 2021-03-11 | ||
CN110743033B (en) * | 2019-10-23 | 2021-12-28 | 辽宁燕阳医疗设备有限公司 | Medical dressing |
TWI749395B (en) * | 2019-11-08 | 2021-12-11 | 高鼎精密材料股份有限公司 | Method for fabricating polymer fiber tubular structure with high patency rate |
DE102019135502B4 (en) * | 2019-12-20 | 2022-07-14 | Acandis Gmbh | Medical set, medical system and covering device for the treatment of aneurysms |
CN111139541B (en) * | 2020-03-10 | 2023-06-30 | 苏州大学 | Stirring type large-batch free liquid level electrostatic spinning device and method |
CN214712943U (en) * | 2020-09-30 | 2021-11-16 | 普利瑞医疗科技(苏州)有限公司 | Medical drug stent |
CN114176597A (en) * | 2021-12-17 | 2022-03-15 | 广东思谷智能技术有限公司 | All-electric spinning high-air-permeability high-hydrophobicity friction nano sensor and preparation method thereof |
WO2023161945A1 (en) | 2022-02-27 | 2023-08-31 | Corneat Vision Ltd. | Implantable sensor |
WO2024075118A1 (en) | 2022-10-03 | 2024-04-11 | Corneat Vision Ltd. | Dental and subperiosteal implants comprising biocompatible graft |
Family Cites Families (109)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2491889A (en) * | 1942-01-21 | 1949-12-20 | Owens Corning Fiberglass Corp | Production of coated glass and the like products |
US3280229A (en) | 1963-01-15 | 1966-10-18 | Kendall & Co | Process and apparatus for producing patterned non-woven fabrics |
DE1491218C3 (en) | 1963-06-15 | 1973-01-04 | Spofa Sdruzheni Podniku Pro Zdravotnickou Vyrobu, Prag | Blood vessel prosthesis and method for making the same |
US3625745A (en) * | 1970-03-18 | 1971-12-07 | Gen Electric | Antithrombogenic article and process |
US3688317A (en) * | 1970-08-25 | 1972-09-05 | Sutures Inc | Vascular prosthetic |
US3860369A (en) * | 1972-11-02 | 1975-01-14 | Du Pont | Apparatus for making non-woven fibrous sheet |
GB1527592A (en) | 1974-08-05 | 1978-10-04 | Ici Ltd | Wound dressing |
FR2382688A1 (en) | 1977-03-04 | 1978-09-29 | Oreal | HARDNESS MEASURING DEVICE |
EP0005035B1 (en) * | 1978-04-19 | 1981-09-23 | Imperial Chemical Industries Plc | A method of preparing a tubular product by electrostatic spinning |
US4223101A (en) * | 1978-07-17 | 1980-09-16 | Inmont Corporation | Method of producing fibrous structure |
DE2965672D1 (en) * | 1978-10-10 | 1983-07-21 | Ici Plc | Production of electrostatically spun products |
EP0011437B1 (en) | 1978-11-20 | 1983-06-22 | Imperial Chemical Industries Plc | A process for setting a product comprising electrostatically spun fibres, and products prepared according to this process |
FI70586C (en) * | 1979-05-03 | 1986-09-24 | Le I Textilnoi | POROEST FYLLMEDELINNEHAOLLANDE REACTIVE MATERIAL VID OEPPNA CELER OCH FOERFARANDE FOER FRAMSTAELLNING AV DETTA |
FR2511014B1 (en) * | 1981-08-10 | 1987-02-06 | Ethicon Inc | PROCESS FOR THE PREPARATION OF A POLYURETHANE RESIN SUITABLE FOR ELECTROSTATIC SPINNING |
US4475972A (en) | 1981-10-01 | 1984-10-09 | Ontario Research Foundation | Implantable material |
GB2142870B (en) * | 1983-07-06 | 1986-06-04 | Ethicon Inc | Manufacturing vascular prostheses by electrostatic spinning |
US4759757A (en) | 1984-04-18 | 1988-07-26 | Corvita Corporation | Cardiovascular graft and method of forming same |
US4657793A (en) * | 1984-07-16 | 1987-04-14 | Ethicon, Inc. | Fibrous structures |
US5679967A (en) * | 1985-01-20 | 1997-10-21 | Chip Express (Israel) Ltd. | Customizable three metal layer gate array devices |
US4798606A (en) | 1985-02-26 | 1989-01-17 | Corvita Corporation | Reinforcing structure for cardiovascular graft |
US4880002A (en) * | 1985-05-30 | 1989-11-14 | Corvita Corporation | Stretchable porous sutures |
GB2181207B (en) * | 1985-10-04 | 1990-05-23 | Ethicon Inc | Improvements in electrostatically produced structures and methods of manufacturing thereof |
US4738740A (en) * | 1985-11-21 | 1988-04-19 | Corvita Corporation | Method of forming implantable vascular grafts |
US4739013A (en) | 1985-12-19 | 1988-04-19 | Corvita Corporation | Polyurethanes |
US4743252A (en) * | 1986-01-13 | 1988-05-10 | Corvita Corporation | Composite grafts |
GB2189738B (en) * | 1986-03-24 | 1989-11-15 | Ethicon Inc | Apparatus for producing fibrous structures electrostatically |
GB8617527D0 (en) | 1986-07-17 | 1986-08-28 | Ici Plc | Spraying process |
US4802145A (en) | 1986-08-01 | 1989-01-31 | Amoco Corporation | Method and apparatus for determining cement conditions |
US5084085A (en) | 1986-08-20 | 1992-01-28 | Fmc Corporation | Herbicidal aryloxyphenyltriazolinones and related compounds |
US4769030A (en) | 1987-04-28 | 1988-09-06 | Corvita Corporation | Monomer and use thereof in crack prevention of implanted prostheses |
US4872455A (en) * | 1987-11-25 | 1989-10-10 | Corvita Corporation | Anastomosis trimming device and method of using the same |
US4997600A (en) * | 1988-05-24 | 1991-03-05 | Mitsubishi Monsanto Chemical Company, Ltd. | Process for preparation of thermoplastic resin sheets |
US4965110A (en) * | 1988-06-20 | 1990-10-23 | Ethicon, Inc. | Electrostatically produced structures and methods of manufacturing |
US5092877A (en) | 1988-09-01 | 1992-03-03 | Corvita Corporation | Radially expandable endoprosthesis |
US5226913A (en) | 1988-09-01 | 1993-07-13 | Corvita Corporation | Method of making a radially expandable prosthesis |
US5019090A (en) * | 1988-09-01 | 1991-05-28 | Corvita Corporation | Radially expandable endoprosthesis and the like |
US4904174A (en) * | 1988-09-15 | 1990-02-27 | Peter Moosmayer | Apparatus for electrically charging meltblown webs (B-001) |
US5024671A (en) | 1988-09-19 | 1991-06-18 | Baxter International Inc. | Microporous vascular graft |
US5024789A (en) * | 1988-10-13 | 1991-06-18 | Ethicon, Inc. | Method and apparatus for manufacturing electrostatically spun structure |
US5298255A (en) * | 1988-10-28 | 1994-03-29 | Terumo Kabushiki Kaisha | Antithrombic medical material, artificial internal organ, and method for production of antithrombic medical material |
US4905367A (en) * | 1988-11-08 | 1990-03-06 | Corvita Corporation | Manufacture of stretchable porous sutures |
US4990158A (en) | 1989-05-10 | 1991-02-05 | United States Surgical Corporation | Synthetic semiabsorbable tubular prosthesis |
US5084065A (en) * | 1989-07-10 | 1992-01-28 | Corvita Corporation | Reinforced graft assembly |
US5545208A (en) * | 1990-02-28 | 1996-08-13 | Medtronic, Inc. | Intralumenal drug eluting prosthesis |
US6004346A (en) | 1990-02-28 | 1999-12-21 | Medtronic, Inc. | Intralumenal drug eluting prosthesis |
CA2038605C (en) | 1990-06-15 | 2000-06-27 | Leonard Pinchuk | Crack-resistant polycarbonate urethane polymer prostheses and the like |
US5147725A (en) * | 1990-07-03 | 1992-09-15 | Corvita Corporation | Method for bonding silicone rubber and polyurethane materials and articles manufactured thereby |
US6117425A (en) | 1990-11-27 | 2000-09-12 | The American National Red Cross | Supplemented and unsupplemented tissue sealants, method of their production and use |
US5116360A (en) * | 1990-12-27 | 1992-05-26 | Corvita Corporation | Mesh composite graft |
GB9115276D0 (en) | 1991-07-15 | 1991-08-28 | Unilever Plc | Skin treatment system |
US5376117A (en) * | 1991-10-25 | 1994-12-27 | Corvita Corporation | Breast prostheses |
US5599352A (en) | 1992-03-19 | 1997-02-04 | Medtronic, Inc. | Method of making a drug eluting stent |
US5383928A (en) * | 1992-06-10 | 1995-01-24 | Emory University | Stent sheath for local drug delivery |
BE1006440A3 (en) * | 1992-12-21 | 1994-08-30 | Dereume Jean Pierre Georges Em | Luminal endoprosthesis AND METHOD OF PREPARATION. |
US5419760A (en) | 1993-01-08 | 1995-05-30 | Pdt Systems, Inc. | Medicament dispensing stent for prevention of restenosis of a blood vessel |
EP0623941B1 (en) * | 1993-03-09 | 1997-08-06 | Hoechst Celanese Corporation | Polymer electrets with improved charge stability |
US5334201A (en) | 1993-03-12 | 1994-08-02 | Cowan Kevin P | Permanent stent made of a cross linkable material |
US5383922A (en) * | 1993-03-15 | 1995-01-24 | Medtronic, Inc. | RF lead fixation and implantable lead |
JPH08507715A (en) * | 1993-03-18 | 1996-08-20 | シーダーズ サイナイ メディカル センター | Drug-inducing and releasable polymeric coatings for bioartificial components |
US5824048A (en) | 1993-04-26 | 1998-10-20 | Medtronic, Inc. | Method for delivering a therapeutic substance to a body lumen |
US5464650A (en) * | 1993-04-26 | 1995-11-07 | Medtronic, Inc. | Intravascular stent and method |
US5360397A (en) * | 1993-07-02 | 1994-11-01 | Corvita Corporation | Hemodiaylsis catheter and catheter assembly |
DE4327595A1 (en) * | 1993-08-17 | 1995-02-23 | Hoechst Ag | Compositions with improved electrostatic properties containing aromatic polyamides, molded articles made therefrom and their use and process for their production |
US5639278A (en) | 1993-10-21 | 1997-06-17 | Corvita Corporation | Expandable supportive bifurcated endoluminal grafts |
US5723004A (en) | 1993-10-21 | 1998-03-03 | Corvita Corporation | Expandable supportive endoluminal grafts |
US5632772A (en) | 1993-10-21 | 1997-05-27 | Corvita Corporation | Expandable supportive branched endoluminal grafts |
US5855598A (en) * | 1993-10-21 | 1999-01-05 | Corvita Corporation | Expandable supportive branched endoluminal grafts |
US5549663A (en) | 1994-03-09 | 1996-08-27 | Cordis Corporation | Endoprosthesis having graft member and exposed welded end junctions, method and procedure |
US5415664A (en) | 1994-03-30 | 1995-05-16 | Corvita Corporation | Method and apparatus for introducing a stent or a stent-graft |
US6001123A (en) * | 1994-04-01 | 1999-12-14 | Gore Enterprise Holdings Inc. | Folding self-expandable intravascular stent-graft |
EP0689805B1 (en) | 1994-06-27 | 2003-05-28 | Corvita Corporation | Bistable luminal graft endoprostheses |
US5629077A (en) * | 1994-06-27 | 1997-05-13 | Advanced Cardiovascular Systems, Inc. | Biodegradable mesh and film stent |
DE9414040U1 (en) * | 1994-08-30 | 1995-01-19 | Hoechst Ag | Nonwovens made from electret fiber blends with improved charge stability |
WO1996011720A1 (en) | 1994-10-17 | 1996-04-25 | Kabushikikaisha Igaki Iryo Sekkei | Drug-releasing stent |
US5637113A (en) * | 1994-12-13 | 1997-06-10 | Advanced Cardiovascular Systems, Inc. | Polymer film for wrapping a stent structure |
US5755722A (en) * | 1994-12-22 | 1998-05-26 | Boston Scientific Corporation | Stent placement device with medication dispenser and method |
US5575818A (en) * | 1995-02-14 | 1996-11-19 | Corvita Corporation | Endovascular stent with locking ring |
EP0810845A2 (en) | 1995-02-22 | 1997-12-10 | Menlo Care Inc. | Covered expanding mesh stent |
US6579314B1 (en) * | 1995-03-10 | 2003-06-17 | C.R. Bard, Inc. | Covered stent with encapsulated ends |
BE1009277A3 (en) | 1995-04-12 | 1997-01-07 | Corvita Europ | Guardian self-expandable medical device introduced in cavite body, and method of preparation. |
BE1009278A3 (en) * | 1995-04-12 | 1997-01-07 | Corvita Europ | Guardian self-expandable medical device introduced in cavite body, and medical device with a stake as. |
US5700269A (en) * | 1995-06-06 | 1997-12-23 | Corvita Corporation | Endoluminal prosthesis deployment device for use with prostheses of variable length and having retraction ability |
CA2178541C (en) * | 1995-06-07 | 2009-11-24 | Neal E. Fearnot | Implantable medical device |
US5609629A (en) | 1995-06-07 | 1997-03-11 | Med Institute, Inc. | Coated implantable medical device |
JPH11511247A (en) | 1995-06-08 | 1999-09-28 | インスティトゥート・フォール・ミリュー−アン・アフリテクニーク | How to determine the degree of cure of the material |
US5627368A (en) | 1995-07-05 | 1997-05-06 | Gas Research Institute | Four-detector formation-density tool for use in cased and open holes |
US5628788A (en) * | 1995-11-07 | 1997-05-13 | Corvita Corporation | Self-expanding endoluminal stent-graft |
US5800512A (en) | 1996-01-22 | 1998-09-01 | Meadox Medicals, Inc. | PTFE vascular graft |
US5749921A (en) | 1996-02-20 | 1998-05-12 | Medtronic, Inc. | Apparatus and methods for compression of endoluminal prostheses |
CA2199890C (en) | 1996-03-26 | 2002-02-05 | Leonard Pinchuk | Stents and stent-grafts having enhanced hoop strength and methods of making the same |
US6252129B1 (en) | 1996-07-23 | 2001-06-26 | Electrosols, Ltd. | Dispensing device and method for forming material |
US5741331A (en) * | 1996-07-29 | 1998-04-21 | Corvita Corporation | Biostable elastomeric polymers having quaternary carbons |
US5797887A (en) * | 1996-08-27 | 1998-08-25 | Novovasc Llc | Medical device with a surface adapted for exposure to a blood stream which is coated with a polymer containing a nitrosyl-containing organo-metallic compound which releases nitric oxide from the coating to mediate platelet aggregation |
SE509834C2 (en) | 1996-09-09 | 1999-03-15 | Bandak As | Filter element for pressure filter |
IL119809A (en) | 1996-12-11 | 2001-06-14 | Nicast Ltd | Device for manufacture of composite filtering material and method of its manufacture |
US5980972A (en) * | 1996-12-20 | 1999-11-09 | Schneider (Usa) Inc | Method of applying drug-release coatings |
US5980551A (en) | 1997-02-07 | 1999-11-09 | Endovasc Ltd., Inc. | Composition and method for making a biodegradable drug delivery stent |
US5843172A (en) | 1997-04-15 | 1998-12-01 | Advanced Cardiovascular Systems, Inc. | Porous medicated stent |
US6371982B2 (en) * | 1997-10-09 | 2002-04-16 | St. Jude Medical Cardiovascular Group, Inc. | Graft structures with compliance gradients |
US6106913A (en) * | 1997-10-10 | 2000-08-22 | Quantum Group, Inc | Fibrous structures containing nanofibrils and other textile fibers |
US5938697A (en) | 1998-03-04 | 1999-08-17 | Scimed Life Systems, Inc. | Stent having variable properties |
US6019789A (en) * | 1998-04-01 | 2000-02-01 | Quanam Medical Corporation | Expandable unit cell and intraluminal stent |
US6013099A (en) * | 1998-04-29 | 2000-01-11 | Medtronic, Inc. | Medical device for delivering a water-insoluble therapeutic salt or substance |
US6265333B1 (en) * | 1998-06-02 | 2001-07-24 | Board Of Regents, University Of Nebraska-Lincoln | Delamination resistant composites prepared by small diameter fiber reinforcement at ply interfaces |
US20020081732A1 (en) * | 2000-10-18 | 2002-06-27 | Bowlin Gary L. | Electroprocessing in drug delivery and cell encapsulation |
US6306424B1 (en) * | 1999-06-30 | 2001-10-23 | Ethicon, Inc. | Foam composite for the repair or regeneration of tissue |
US6682004B2 (en) | 1999-08-18 | 2004-01-27 | The Procter & Gamble Company | Electrostatic spray device |
US6270793B1 (en) | 1999-09-13 | 2001-08-07 | Keraplast Technologies, Ltd. | Absorbent keratin wound dressing |
US20020084178A1 (en) * | 2000-12-19 | 2002-07-04 | Nicast Corporation Ltd. | Method and apparatus for manufacturing polymer fiber shells via electrospinning |
-
2001
- 2001-10-19 US US09/982,017 patent/US20020084178A1/en not_active Abandoned
- 2001-12-17 US US10/433,621 patent/US7112293B2/en not_active Expired - Fee Related
- 2001-12-17 CA CA002432159A patent/CA2432159A1/en not_active Abandoned
- 2001-12-17 CN CNA018226671A patent/CN1599582A/en active Pending
- 2001-12-17 IL IL15651201A patent/IL156512A0/en unknown
- 2001-12-17 IL IL15651401A patent/IL156514A0/en unknown
- 2001-12-17 MX MXPA03005552A patent/MXPA03005552A/en unknown
- 2001-12-17 DE DE60141710T patent/DE60141710D1/en not_active Expired - Lifetime
- 2001-12-17 MX MXPA03005553A patent/MXPA03005553A/en unknown
- 2001-12-17 AU AU2002222494A patent/AU2002222494A8/en not_active Abandoned
- 2001-12-17 CN CNA018227031A patent/CN1635861A/en active Pending
- 2001-12-17 MX MXPA03005551A patent/MXPA03005551A/en unknown
- 2001-12-17 EP EP01271185A patent/EP1353606B1/en not_active Expired - Lifetime
- 2001-12-17 AT AT01271185T patent/ATE462371T1/en not_active IP Right Cessation
- 2001-12-17 IL IL15651301A patent/IL156513A0/en active IP Right Grant
- 2001-12-17 EP EP01271184A patent/EP1578306A2/en not_active Withdrawn
- 2001-12-17 CA CA2432164A patent/CA2432164C/en not_active Expired - Fee Related
- 2001-12-17 CA CA002432156A patent/CA2432156A1/en not_active Abandoned
- 2001-12-17 AU AU2002222494A patent/AU2002222494A1/en not_active Abandoned
- 2001-12-17 AU AU2002216342A patent/AU2002216342A1/en not_active Abandoned
- 2001-12-17 AT AT01271232T patent/ATE460903T1/en not_active IP Right Cessation
- 2001-12-17 CN CNA018226612A patent/CN1489513A/en active Pending
- 2001-12-17 JP JP2002550881A patent/JP2004532665A/en active Pending
- 2001-12-17 WO PCT/IL2001/001171 patent/WO2002049535A2/en active Application Filing
- 2001-12-17 WO PCT/IL2001/001168 patent/WO2002049678A2/en active Application Filing
- 2001-12-17 US US10/433,622 patent/US7115220B2/en not_active Expired - Fee Related
- 2001-12-17 AU AU2002216340A patent/AU2002216340A1/en not_active Abandoned
- 2001-12-17 WO PCT/IL2001/001172 patent/WO2002049536A2/en active Application Filing
- 2001-12-17 JP JP2002551015A patent/JP2005507464A/en active Pending
- 2001-12-17 JP JP2002550882A patent/JP4145143B2/en not_active Expired - Fee Related
- 2001-12-17 DE DE60141607T patent/DE60141607D1/en not_active Expired - Lifetime
- 2001-12-17 EP EP01271232A patent/EP1355677B1/en not_active Expired - Lifetime
-
2002
- 2002-03-19 US US10/471,276 patent/US7276271B2/en not_active Expired - Fee Related
- 2002-03-19 US US10/471,277 patent/US7244116B2/en not_active Expired - Fee Related
-
2003
- 2003-06-18 IL IL156513A patent/IL156513A/en not_active IP Right Cessation
- 2003-06-18 IL IL156514A patent/IL156514A/en not_active IP Right Cessation
-
2006
- 2006-01-04 HK HK06100173.3A patent/HK1080347A1/en unknown
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN104713909A (en) * | 2015-04-10 | 2015-06-17 | 湖南农业大学 | Simple method for authenticating fluorine injury of plants |
Also Published As
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US7112293B2 (en) | Method and apparatus for manufacturing polymer fiber shells via electrospinning | |
EP1377421A2 (en) | Polymer fiber tubular structure having improved kinking resistance | |
US20070031607A1 (en) | Method and apparatus for coating medical implants | |
Bera | Literature review on electrospinning process (a fascinating fiber fabrication technique) | |
US20090091065A1 (en) | Electrospinning Apparatus For Producing Nanofibers and Process Thereof | |
Moroni et al. | Fiber diameter and texture of electrospun PEOT/PBT scaffolds influence human mesenchymal stem cell proliferation and morphology, and the release of incorporated compounds | |
Park et al. | Apparatus for preparing electrospun nanofibers: designing an electrospinning process for nanofiber fabrication | |
KR101201412B1 (en) | Preparation method for highly porous core-shell nanoweb | |
GB2427382A (en) | Electrospinning of fibres | |
JPS6043981B2 (en) | Tubular fibril product for in-vivo conduit prosthesis and its manufacturing method | |
WO2002092888A1 (en) | Apparatus and methods for electrospinning polymeric fibers and membranes | |
US20080211121A1 (en) | Device for manufacturing fabrils and method thereof | |
US20050048274A1 (en) | Production of nanowebs by an electrostatic spinning apparatus and method | |
WO2006018838A2 (en) | Method and system for manufacturing electrospun structures | |
Bowlin et al. | Electrospinning of polymer scaffolds for tissue engineering | |
WO2009102365A2 (en) | Production of electrospun fibers with controlled aspect ratio | |
KR20120111381A (en) | A double-layered tube-type porous scaffold comprising biodegradable polymer and manufacturing method thereof | |
US20240018692A1 (en) | Device and method for producing an anisotropic fibre structure by electrospinning | |
CN113710835B (en) | Electrospinning apparatus and method for forming oriented fibers | |
Nayak et al. | Review of literature: Melt electrospinning | |
JP2004290133A (en) | Cell culture substrate and method for producing the same | |
CN113288509A (en) | Preparation method and device of PTFE (Polytetrafluoroethylene) covered stent | |
KR101847478B1 (en) | Nanofiber electrospinning device for spinning nanofibers on an insulating layer and manufacturing method thereof | |
Buchko et al. | Electric field mediated deposition of bioactive polypeptides on neural prosthetic devices | |
Hsu | Electrospinning of Poly ([epsilon]-Caprolactone). |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
EEER | Examination request | ||
FZDE | Discontinued |