WO2006082270A1

WO2006082270A1 - Novel 3-d polymer scaffold for tissue regeneration and preparation method thereof

Info

Publication number: WO2006082270A1
Application number: PCT/ES2006/000042
Authority: WO
Inventors: Laura Santos Esteve
Original assignee: Laura Santos Esteve
Priority date: 2005-02-01
Filing date: 2006-02-01
Publication date: 2006-08-10
Also published as: ES2258396B1; ES2258396A1

Abstract

The invention relates to a novel 3-D polymer scaffold for tissue regeneration, having a porous structure which is the inverse or negative of a three-dimensional porogen or template (figure 1) resulting from the sintering of stacked meshes of nylon fibres. The invention is characterised by a regular orthogonal network (figures 2 to 5) comprising aligned and interconnected pores and cylindrical channels of uniform size and free of residual porogen, with a variable porosity of more than 75 % and a variable channel and pore diameter of the µm order of magnitude. The novel polymer scaffold is obtained by: infiltration and polymerisation of the cross-linking material in the template, elimination of the porogen by means of leaching, and drying of the resulting porous matrix. Said scaffold is chemically and mechanically stable and is particularly suitable for use in the regeneration or repair of human or animal tissues.

Description

NEW 3D POLYMER SCAFFOLD FOR THE REGENERATION OF FABRICS AND

YOUR PREPARATION TECHNIQUE

OBJECT OF THE INVENTION

The present invention relates to a new three-dimensional polymeric (3D) scaffold for tissue regeneration, with a high degree of porosity and structural regularity, as well as its preparation technique.

This new support for tissue engineering based on biocompatible polymers is characterized by a highly regular three-dimensional porous architecture with a high degree of porosity, manifested by an orthogonal network of pores and channels completely interconnected, free of residual porogen, resulting in chemical and chemical stability. mechanically for the purpose it is intended for.

The ideal structural characteristics of the developed scaffolds are achieved by a novel and cheap technique, based on the use of a three-dimensional or tempered porogen produced from sintered meshes of nylon fibers or another similar polymer, which makes the matrix resulting from the infiltration and polymerization of the crosslinking material is the inverse or negative structure of the template, hence the geometric regularity of interconnected pores and channels. As a representative example of how this method can be applied, the manufacture of a scaffold made of MMA methyl methacrylate will be described. i

These architectures have been characterized by scanning electron microscopy, porosimetry and dynamic-mechanical properties.

The results have demonstrated the feasibility of the technique to prepare macroporous and microporous structures, suitable for use in tissue or tissue engineering, within what is the technical field of biotechnology, where

The invention finds applications, both ex vivo and in vivo, serving as structures to support and increase the efficiency of in vitro cell cultures, or as supports where live cells and biological fibers can grow, improving bio-integration and anchoring. of the material in the host tissue. STATE OF THE PREVIOUS TECHNIQUE

Tissue Engineering, or tissue engineering, is an interdisciplinary field that combines engineering and life sciences to develop techniques that allow the renewal, maintenance or improvement of living tissues and organs. Its fundamental objective is the creation of a natural tissue with the ability to restore the function of a lost organ or tissue, which the organism has not been able to regenerate under physiological conditions. This aims to solve the current limitations: low number of donors, rejections, etc.

Tissue engineering needs support structures (scaffolds in English) for cell growth and as a physical aid to direct the formation of new tissue. Most of the techniques used use three-dimensional polymeric scaffold (3D) structures, composed of natural or synthetic polymers.

The polymeric scaffolds are presented in structures with a complex internal architecture, with channels and pores that provide a place for the settlement and proliferation of the cells, based on a biocompatible material, which serves as a biomolecular signal to promote the rejeneration of the tissue in the instead of the implant, and also biodegradable, so that the support degrades over time after implantation, being finally replaced by the newly formed tissue.

Ideally, a polymeric scaffold for tissue engineering should have the following characteristics: 1) It must have adequate surface properties to allow cell anchoring, which facilitates cell adhesion, proliferation and differentiation, 2) it must be biocompatible, 3) highly porous , with a large area or area / volume ratio, forming a network of pores of uniform size and interconnected to facilitate both cell growth, allowing cells to develop throughout the network, as the entry and exit of nutrients and waste products, and 4) must possess sufficient mechanical strength to withstand any stress in vivo. This last requirement is difficult to combine with the high porosity in volume of the material, hence it is necessary to use polymeric matrices of special or reinforced properties, especially if the polymer is a hydrogel.

The design of the polymeric scaffolds depends on the applications considered, but in any case structures must be obtained with the indicated characteristics necessary for their correct function. Achieving it successfully is fundamentally conditioned by two factors: For the materials used, both for the porogen, which is the mold used, and for the cross-linking polymer, which is infiltrated into the porogen to constitute the scaffold; and, as a second factor, by the structural architecture, external and internal, of the shaped support material, manifested basically by the degree of porosity (surface / volume fraction) and by the geometry and size of the pores, always counting also with the scaffolds They must be easily processable in 3D 3D shapes.

The materials used in the porogenic or porogenic system may be poly (methyl methacrylate) and poly (ethyl methacrylate) grains, polyamide 6.6 and poly (acrylonitrile) fibers and meshes. As for the scaffolds, these can be based on hydrophilic, hydrophobic or hydrogel polymers, or a combination of them in the form of copolymers or interpenetrated polymer networks, which are elastomeric or rigid at body temperature, and which have a Porous structure of controllable characteristic size and topology.

Polymers based on polylactic acid (PLA), polyglycolic acid (PGA) and their copolymers (PLGA) are the most widely investigated biocompatible polymers for tissue engineering scaffolds and for bioimplants (Rothen-Weinhold et al. 1999; Stancari et al. 2000) and controlled and nutrient-free delivery devices (Putney, 1999). Combinations of these polymers with hydroxyapatila (FLA) are currently being investigated as bone fixation devices in orthopedic, craniofacial, maxillofacial and reconstructive surgery (Furukawa et al. 2000). Polyanhydrides, polyorthoesters, polycaprolactones, polyfumarates, polycarbonates, and bioactive crystals (Stamboulis et al. 2002) between a multitude of other synthetic biomaterials are being investigated for tissue engineering scaffolds and also controlled nutrient distribution.

Acrylic and methacrylic monomers are also used as a constituent of the scaffolds.

Based on this wide range of polymeric materials, various techniques have been developed for the structural design of 3D scaffolds for tissue implantation engineering, among which are: a) Phase separation, b) Foaming gas, c) Fiber bonding, d) Photolithography, e) Solid free form (SFF), f) Solvent cast in combination with partióle leaching, among others.

However, none of these techniques has managed to achieve an ideal three-dimensional architecture model so that the scaffold can fulfill its purpose in the desired way, even using high-cost equipment, for the reasons discussed below.

Thus, by means of the known phase separation technique, porous structures can be easily obtained by adjusting thermodynamic and kinetic parameters, but, due to the complexity of the variables involved in the process, the porous structure cannot be easily controlled.

It is also difficult to obtain large pores and may exhibit lack of interconnection.

Gaseous foaming (gas foaming) has the advantage of processing at room temperature, but produces a non-porous outer layer, and a mixture of open and closed pores in the center of the scaffold, leaving the interconnectivity incomplete. The main disadvantage of the method is that it often results in a cellular structure not connected within the scaffold.

The fiber crosslinking technique (fiber bonding) provides a large area for cell adhesion and rapid diffusion of nutrients, in favor of cell growth and survival. However, these scaffolds, such as those formed by firm networks of polyglycolic acid (PGA) fibers, lack the necessary structural stability. In addition, the technique does not lend itself to an easy and independent control of the porosity and pore size. Photolithography (photollthography) has also been used for the design of scaffolds, allowing to obtain structural arrangements with great precision, although it is not always required. In any case, the drawback of this technique lies in the high cost of the equipment necessary to apply it.

SFF scaffolds manufacturing methods (solid free form or Solid free form) provide excellent control over the external shape, geometry and internal interconnectivity of the pores, but offer a limited resolution at micrometric scale, in addition to the minimum size of the Global pores is 100 μm. It also requires a complicated correction of the scaffold design due to the anisotropic contraction during manufacturing, and somewhat expensive equipment.

Finally, the casting of solids in combination of leachate (solvent casting in combination with particulate leaching), which involves the smelting / emptying of a mixture of monomers and the solution of the initiator and a porogen in a mold, the polymerization, followed of leachate to extract the porogen with the appropriate solvent to generate the pores, it is a cheap method, but it still has to overcome some disadvantages to find engineering applications, mainly the problem of porogen remains, irregular pore shapes and insufficient interconnectivity , among others.

In view of all these difficulties, the objective of the present invention is to present a new model of porous scaffolds of 3D architecture for tissue engineering, with structural features unmatched to fulfill its purpose, achieved by a technique, also claimed as of own invention, which is simple and cheap, and that overcomes the problems of the aforementioned techniques.

The new technique is based on using a three-dimensional or tempered porogen obtained from sintered meshes of nylon fibers, although it can also be created using sintered meshes of other polymeric materials of similar characteristics to nylon or polyamide, so that the scafold that results of the infiltration and polymerization of the constitution material in said tempera be

The inverse or negative structure thereof, which presents a geometric regularity of interconnected pores and channels so far not achieved. Scaffols 3D for engineering of fabrics using nylon are disclosed in previous patents, for example, for US patents with publication numbers US5736372, US6596296, US5266480 or US6471993, among others, which obtain the product by some of the techniques mentioned above, but the difference is that in all of them nylon is used as a scaffold, when the material that is claimed below is a negative that does not have to be made of nylon, because what really is of invention is its three-dimensional structure, of suitable geometry , created from a different technique.

DESCRIPTION OF THE INVENTION

The new 3D polymeric scaffold for tissue regeneration developed is constituted by a biocompatible polymer of hydrophobic, rigid or flexible type, or of rigid hydrophilic type, or a combination of both types of polymers in the form of copolymers or interpenetrated polymer networks, plus a cross-linking agent, and is characterized by being the inverse or "negative" structure of a three-dimensional or "tempered" porogen, resulting from the sintering of superimposed meshes of synthetic polyamide or nylon fibers, or other similar polymeric material, and which is eliminated after the polymerization of the crosslinking material thereon, presenting a regular three-dimensional network of pores and orthogonal cylindrical channels of uniform size and clean of residual porogen, alienated and interconnected transversely through a succession of uniformly distributed parallel layers, practically superimposable, with a variable porosity above 75% (pore volume fraction), depending on the pressure and temperature conditions of the sintering process, and with a pore and channel diameter that can vary in order of magnitude μm for each matrix obtained, depending on the polymeric material used in obtaining the three-dimensional porogen.

The resulting support structure is quite stable, even during the leaching of the porogen, and can be obtained with different degrees of porosity and channel size, depending on the porogenic material used and the sintering conditions. of the same to get the temple. In addition, the structure can be produced in different combinations of polymeric materials, thus adjusting the ratio of hydrophilic / hydrophobic behavior of the scaffold. In fact, the structure has been obtained based on copolymers of various compositions (pEA-co-pHEMA) and IPN's.

In a preferred embodiment, the porogenic material of the three-dimensional tempera is nylon fabric 6,6, and the resulting cross-linking material of the resulting porous matrix is methyl methacrylate (MMA, 99%), together with ethylene glycol dimethacrylate (EGDMA, 98 %) as a crosslinking agent, Io leads to a scafold with 80% porosity and an average pore and channel diameter of 72 ± 6 μm.

The method by which this new porous structure support for tissue engineering is obtained, basically consists in creating a template using sintered meshes of nylon fibers or another equivalent polymer, such as a three-dimensional structure of porogenic material, which is removed after polymerization. of the matrix. In this way, the resulting scaffold has the inverse structure of the template, which is a structure with orthogonal pores and cylindrical channels uniformly distributed and interconnected, with a level of porosity or surface / volume ratio around 80%.

Specifically, the preparation technique of the new 3D polymeric scaffold comprises the following stages:

The first and fundamental is the preparation of the three-dimensional porogen mesh, by stacking and, if necessary, pressing, of rectangular layers of nylon fiber fabrics or other equivalent polymer, to be subjected to isothermal sintering and pressure in an electric oven , resulting in a stable three-dimensional mesh, with a reticular size that depends on the pressure, temperature and time used during the sintering process. Thus, for nylon 6,6 used as a porogenic material, an ideal template is achieved by stacking eight layers of fiber fabrics of that polyamide and its isothermal sintering at 220 ⁰ C 'for ten minutes, being necessary a final roughing for eliminate irregularities

However, when the matter! used as a porogen are poly (acrylonitrile) fibers, the preparation of the three-dimensional mesh or template is not performed by thermal sintering, but the stacking of fiber fabrics of said material is subjected to pressure in the atmosphere of a suitable solvent, such as, for example, dimethylformamide.

Obtained the three-dimensional porogenic system or template, the polymeric material constituting the structural matrix is infiltrated therein, using a glass mold of suitable size, after which the system is subjected to polymerization under a nitrogen atmosphere. When the polymeric material is methyl methacrylate (MMA), together with ethylene glycol dimethacrylate (EGDMA) as a cross-linking agent and azo-bis-isobutyronitrile (AZBN) as initiator, polymerization is carried out at 65 ° C in a thermostatic bath and nitrogen atmosphere during 30 minutes, and then at 65 ° C in the oven for 4 hours and at 75 ° C for the next 24 hours.

After the polymerization, the removal of the porogen is carried out by leaching in nitric acid as an extracting agent, and subsequent washing in ethanol.

Finally, the resulting porous matrix is subjected to two-stage drying: first in air for 24 hours and then under vacuum at a suitable temperature for 48 hours, obtaining the 3D polymeric scaffold, with an inverse structure to that of the temple used as a porogen, which It is kept in a desiccator, being ready for characterization and use.

This new technique allows to obtain in an economic way scaffolds that, as it has been seen, present highly regular pore shapes and arrangements, with a complete interconnection, giving rise to mechanically stable structures without porogen residues.

This solves a problem that was pending, since although there were characterized polymeric materials more or less suitable for scaffolds, with adequate, biocompatible and biodegradable surface properties, the most important factor so that these structural supports can fulfill their purpose in Tissue engineering, which is the high porosity required, with regularly interconnected pore networks and channels, was not completely resolved, having now been fully satisfied by the structural characteristics of the new support achieved. In addition, the costs of the procedure are many cheaper than those of the techniques that allow obtaining acceptable structures, such as the photolithography or the Solid free form (SFF), already mentioned.

BRIEF DESCRIPTION OF THE FIGURES

By making a brief reference to the drawings, such structural characteristics suitable for the scaffold presented can be seen.

Figure 1 is an SEM micrograph (scanning electron microscopy of the standard electron) of the three-dimensional temple or porogen formed by the sintered nylon fabrics, which serves as an architectural template for the formation of the polymeric scaffold, which is the key to its unique structure. Figure 2 is a SEM micrograph of the front surface of the methyl methacrylate scaffold (PMMA) formed.

Figure 3 is an enlargement of the same sample that shows in detail the parallel channels and the normal interconnecting pores.

Figures 4 and 5 correspond to SEM micrographs of the lateral surface (cross section) of the methyl methacrylate scaffold (PMMA), Ia 4 in a general view and Ia 5 in enlarged detail, where the absence of residual porogen in Ia network of pores and interconnected channels.

In all these micrographs it is observed that the regularity of the new support is absolute, within an orthogonal three-dimensional system. In addition, the mechanical properties are not left behind, as shown in the graphs of Figures 6 and 7, which are a comparison of the mechanical properties of the porous support obtained from methyl methacrylate against the bulk thereof, without treatment.

The graph of Figure 6 represents the variation of the dynamic storage modulus E 'as a function of temperature at 1 Hz for methyl methacrylate, ^both' bulk, nonporous (line circles) and in the porous architecture of the scaffold formed (line of squares), while that of Figure 7 represents the tangent of dynamic-mechanical losses Tan δ as a function of the temperature at 1 Hz for methyl methacrylate, both in bulk, not porous (line of circles), and in the porous architecture of the scaffold formed (line of squares).

PREFERRED EMBODIMENT OF THE INVENTION

An example of the technique for preparing the new 3D polymeric scaffold object of this invention, not limiting thereof, while, as noted above, it can be played with different types of starting polymeric materials and under different sintering conditions of the Porogen, set out below.

As a porogenic material, polyamide 6.6 (nylon 6.6) fabric is chosen, and as a crosslinking material for scaffold, methyl methacrylate (MMA, 99%) and ethylene glycol dimethacrylate (EGDMA, 98%), the latter as agent crosslinker, using azo-bis-isobutyronitrile (AZBN) as initiator.

60% nitric acid (for analysis), 99.7% ethanol (quality / degree of synthesis), distilled water, 99% purity n-octane (p _n - _O c _t a _n o = 0.7 g / cm ³ ), are also necessary.

With these starting materials and products, the stages are as follows:

1. Preparation of the three-dimensional porogen mesh. -

Eight rectangular layers of nylon fiber fabrics are stacked and sintered by an isothermal process at 22O ⁰ C for ten minutes in an electric oven.

To sinter the two-dimensional fabrics to a three-dimensional mesh, programs at various temperatures were tested. Below 200 ⁰ C samples were not sintered nylon and above 235 ⁰ C samples melted because the temperature at which the nylon melts.

The heat treatment at 220 ⁰ C of the sintering program described a consistent attachment between the sheets of stacked material, probably due to a process that involved the fusion of small crystals and the recrystallization of individual fibers in contact with each other. This is seen in the small peak of endothermic fusion between 230 and 240 ⁰ C, prior to the melting zone of the material (maximum of the melting endotherm 260 ⁰ C) that is characteristic of a fraction of small crystals, probably created in the isothermal step of the treatment, since the endotherm is absent in the thermogram of the natural fabric. Thus, a three-dimensional mesh of stable porogenic material is obtained, with a network of truly connected channels and pores, as can be seen in the SEM micrograph of Figure 1.

2. Manufacture of scaffold, -

The three-dimensional sintered mesh is placed between two glass plates covered with a cellophane film and sealed with rubber spacers. The appropriate amounts of MMA, crosslinker EGDMA (1% by weight) and AZBN as a free radical-thermal initiator (0.2% by weight) are mixed in a beaker. The liquid and homogeneous mixture of monomer, initiator and crosslinking agent is poured into the glass mold where the nylon mesh is located. The polymerization is conducted at 6'5 ⁰ C in a thermostatic bath for 30 minutes under nitrogen. Then, the mold is placed in an oven at 65 ° C for four hours followed by an increase in temperature at 75 ° C for 24 hours.

Once the polymerization process is completed, the sample is extracted from the mold and sanded in a polishing machine.

To remove the porogen, the sample is immersed at room temperature for 5 days in nitric acid to dissolve the nylon mesh, then the material is washed in a Soxhlet extractor, using ethanol as solvent and for 48 hours, to extract substances from Low molecular weight and remove the remains of nitric acid.

Finally, the sample is dried at ambient conditions for one day, allowing it to shrink slowly, but prevent coiling and flexing at the beginning of drying, finally, dried at vacuum at 120 ⁰ C for 48 hours. The resulting scaffold is stored in a desiccator until it is characterized. After leaching with nitric acid from the porogen mesh, the scaffold already shows its characteristic porous structure, through an orthogonal network of interconnected pores and channels, but must be subjected to a final drying phase to extract low molecular weight substances and remove The remains of acid. The final structure of the scaffold is clearly seen in Figures 2 to 4.

Figure 2 shows the outer surface of the scaffold, showing its highly regular structure, with an arrangement of identical pores in an orthogonal assembly of cylindrical channels. Figure 3 is an enlargement of the same sample. The darkest circular points are the transverse interconnections between the layers, which are uniformly distributed in the matrix, with a regular, almost superimposable shape. The average diameter is 67 ± 5 μm.

Figures 4 and 5 show side views of the scaffold. The deep inspection inside the samples demonstrates the absence of the residual porogen. In Figure 4 the detail of the external surface can be observed, in the left part of the image, where again the high regularity is appreciated. The diameters of the scaffold pore channels were measured in the enlarged view of the cross section of Figure 5. The average diameter is 72 ± 6 μm.

3. Characterization of scaffolds.-

The scaffolds resulting from the new procedure described were characterized by scanning electron microscopy (SEM); The mechanical characteristics and the porosity were also measured.

Differential scanning calorimetry (DSC), -

The DSC measurements were taken on the samples of the nylon fabric in a Pyris 1 instrument (Perkin Elmer). The melting and glass transition temperature, T ₉ , of commercial nylon was determined in explorations consisting of heating from 25 ° C to 280 ⁰ C with a heating rate of 10 ° C / min. To determine possible changes in the initial nylon during the manufacture of the template, the samples were by heating steps of 25 ° C to 220 ⁰ C to 10 ° C / min, followed by an isothermal step 220 ⁰ C for 10 minutes. The next step was cooling from that temperature to 25 ° C to 10 ° C / min, followed For another step ¡sotherm of 25 ° C for one minute, and finally a heating of 25 ° C to 280 ⁰ C at 10 ° C / min. All measurements were repeated three times.

Scanning electron microscopy (SEM) analysis .-

Scanning electron microscopy (JEOL JSM6300) was used at 10 KV to study the morphology of the samples. For this purpose the samples were cut transversely with a hot razor blade. The samples were previously coated with gold using a sputter coater (Baltec Sed 005).

All dimensions were measured with respect to the bar of the scale in each SEM micrograph, using the image tools of the program.

Determination of the porosity. -

The porosity was determined with the measure of the apparent density of the scaffold. For this, distilled water was used as filler of the porous structure. The dried sample was weighed and placed in a glass tube connected to a vacuum pump, and filled with distilled water before removing the vacuum. Then the matrix filled with water was weighed again and the porosity calculated as:

In ₁ / π (%) = ^ - 100 = ' ^Pι -100

where π is the porosity, v _p and v _t are the volume occupied by the pores and the volume of the matrix, respectively, p is the density of the liquid, p _m is the density of the filler material (PMMA in this case), m, and _{m m} are the liquid mass (wet) and the dry mass of the matrix respectively.

The density of the dry non-porous crosslinked mesh of PMMA was determined by weighing the samples in the air (m _a ) and n-octane (m ₀ ), and applying the following expression: r PMMA Pn-oc tanning tan om _a + m ₀

A Mettler Toledo AX205 balance with a sensitivity of 0.00001 g and a kit for density determination for AT / AX balances were used for the measurements.

The porosity of the scaffold was determined according Io described above, equation (1), with a value of Ea-u pp _MMAentr ado _z = _1/18 g / cm ³ determined by equation (2). An average scaffold porosity of 80% was thus obtained.

All samples were easy to handle and physically stable.

Dynamic-mechanical properties.-

Samples of PMMA bulk and porous architectures are cut into bars and measured on an instrument DMS210 (Seiko) from 30 ⁰ C to 25O ⁰ C at a heating rate of 2 degrees / min and a frequency of IHZ.

The mechanical characteristics of the scaffolds depend on the porosity. Figure 6 (Paper inventor) compares the dynamic module E 'of a scaffold with that of the thickness of PMMA, that is, with a non-porous matrix of this polymer, obtained by the same procedure but without infiltration into the template. The effect of the porosity is a vertical change of the curve, which corresponds to a decrease in the rubber and vitreous modules of the scaffold by a factor of ten compared to the bulk modules. This is due to the decrease in the effective area of the cross section due to the porosity. It is notable, however, that the porous structure retains the rest of the mechanical characteristics of the bulk material, which is not altered by the production process: the fall of the module in the region of the glass-rubber transition is practically the same as in the bulk material, as well as the glass transition temperature. This can be seen more clearly in Figure 7 (Paper inventor), where the loss tangent factor δ is represented. There the coincidence in the temperature and the intensity of the main transition is evident for both materials. The dispersion of the data of E 'and tan δ after the vitreous transition are expected characteristics of Ia measurement in porous structures probably due to factors such as poorer adhesion in the clamps of the apparatus.

IN DUSTRIAL APPLICATION-

The scaffolds developed by means of the new described technique, with notably improved structural characteristics, find perfect application in tissue engineering, in the manufacture of the support structures for the regeneration or repair of human or animal tissues.

The three-dimensional porous architectures object of the biotechnology industry and which are then formally claimed, are useful in medical applications such as physical supports for cell cultures, support ring for corneal prosthesis, nerve regeneration, chondrocyte culture and systems of controlled release of drugs, among others. They could also find use in other areas in which pore morphology can play an essential role, such as in membranes and filters.

Claims

1. New 3D polymeric scaffold for tissue regeneration, consisting of a biocompatible polymer of the hydrophobic, rigid or flexible type, or of the rigid hydrophilic type, or a hydrogel, or a combination of these types of polymers in the form of copolymers or networks interpenetrated with polymer, plus a cross-linking agent, essentially characterized by being the inverse or "negative" structure of a three-dimensional or "templated" porogen (figure 1) resulting from the sintering of superimposed meshes of synthetic polyamide or nylon fibers, or other polymeric material similar, and that is eliminated after the polymerization of the crosslinking material thereon, this new structure presenting a regular three-dimensional network (figures 2 to 5) of orthogonal cylindrical channels and channels of uniform size and clean of residual porogen, alienated and interconnected transversely through a succession of uniformly distributed parallel layers (figures 4 and 5), practically superimposable, with a variable porosity above 75% (fraction of pore volume), depending on the pressure and temperature conditions of the sintering process, and with a pore and channel diameter that can vary in order of magnitude μm for each matrix obtained, according to the polymeric material used in obtaining the three-dimensional porogen.

2. New 3D polymeric scaffold for tissue regeneration, according to claim 1, wherein the porogenic material of the three-dimensional tempera is nylon fabric 6.6, and the cross-linking material is methyl methacrylate (MMA, 99%), together with ethylene glycol dimethacrylate (EGDMA, 98%) as a crosslinking agent, the structure having a porosity degree of 80% and an average pore and channel diameter of 72 ± 6 μm.

3. Preparation technique of the new three-dimensional polymeric scaffold of the first claim, characterized in that it comprises the following steps: i) Preparation of the three-dimensional porogen mesh, by stacking layers of nylon fiber fabrics or equivalent polymeric material, and sintering Isotherm and pressure thereof in an electric oven, resulting in a stable three-dimensional mesh or template, with a reticular size that depends on the pressure, temperature and time used during e! sintering process, ii) infiltration in the template obtained from the polymeric material constituting the matrix structure, and subsequent polymerization in a nitrogen atmosphere, iii) removal of the porogen by leaching as an extracting agent and subsequent washing in ethanol, and iv) drying of the resulting porous matrix in air for 24 hours and then under vacuum at a suitable temperature for 48 hours.

4. Preparation technique of the new three-dimensional polymeric scaffold of the first claim, according to the preceding claim, characterized in that when the material used as a porogen is poly (acπlonitπlo) fibers, the preparation of the three-dimensional mesh or template is carried out under pressure in an atmosphere of a suitable solvent, such as dimethylformamide.

5. Preparation technique of the new three-dimensional polymeric scaffold of the second claim, consisting of a porous matrix of methyl methacrylate MMA and ethylene glycol dimethacrylate, as negative of a three-dimensional porogen based on nylon 6,6, characterized in that it comprises the following stages: i) Preparation of the three-dimensional porogen mesh, by stacking eight rectangular layers of 6,6 nylon fiber fabrics, and isothermal sintering at 220 ⁰ C and under pressure for ten minutes in an electric oven, with the resulting tempering of the resulting template eliminate irregularities, ii) infiltration in the template of a mixture of methyl methacrylate MMA, ethylene glycol dimethacrylate EGDMA (1% by weight) as crosslinking agent, and azo-bis-isobutyronitrile AZBN (0.2% by weight) as initiator and subsequent polymerization at 65 ⁰ C in water bath and nitrogen atmosphere for 30 minutes, then at 65 ° C oven for 4 hours and 75 ° C for the next 24 hours,. iii) elimination of the porogen leaching in nitric acid as an extracting agent and subsequent washing in ethanol, and iv) drying the resulting porous matrix to air for 24 hours and then under vacuum at 12O ⁰ C temperature for 48 hours.