JP2011019990A - Use of tissue repair matrix - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a porous three-dimensional tissue repair matrix which is biodegradable. <P>SOLUTION: The matrix has a shape memory, is porous, and is three-dimensionally fixed, and is biodegradable. The matrix has a biopolymer fiber which is insoluble and mineralized and a water-soluble binder which becomes insoluble by crosslinking and is in a compressed condition in the original size, shape, and porosity of the matrix. The matrix (a) introduces the delivery vehicle including the matrix into the site to be treated and (b) releases the matrix from the delivery vehicle, and the matrix returns to the original size, shape, and porosity. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to materials useful for bone tissue repair.

There are a number of materials that have been studied to initiate bone repair and / or to restore or replace missing bone, which solves the problem of stimulating bone formation at specific sites.
In the method used to solve, this problem is a configurational method, an implant material usually consisting of a metal ceramic or other inorganic material in a form intended to mimic a lost bone form Is inserted at the site where bone replacement is required. The host may reject the material or failure of integration of the implant with normal skeletal tissue may occur. Some ceramic materials, such as tricalcium phosphate ceramic, are biocompatible with the host and bone, but when used as an implant, lack sufficient mechanical properties of bone for general use. And the bone does not grow constantly and is not taken into the implant.

  Another method involves replacing lost bone tissue with a matrix that functions as a support on which new bone growth can occur. The theory is that the matrix attracts cells that are involved in the path of osteogenesis, and new bone grows in and through the matrix by a method called osteoconduction. Heterogeneous bone (non-hostbone) grafts are used in this method, but with a substantially high failure rate. Even when heterogeneous genotype grafts are tolerated by the host, healing time for integration and tolerance to mechanical stress are relatively long compared to autogenous bone (host bone) transplantation. The use of allogeneic bone also presents problems with hereditary viral drugs.

  The third method involves a process known as osteoinduction, where the substance induces new bone growth from the host's undifferentiated cells or tissue, usually around a temporary matrix. To occur. Many compounds have been found to have such capabilities. See, for example, Glowacki US Pat. No. 4,440,750, Urist et al. 4,294,753 and 4,455,256, Seyedin et al. 4,434,094 and 4,627,982. The most effective of these compounds are believed to be proteins that stimulate bone formation. However, when synthesized from natural sources, they are present in very low concentrations and require large amounts of starting material even to obtain the lowest amount of material for the experiment. The availability of such proteins by recombinant methods may ultimately make use of such proteins themselves, which have more substantial value. However, there may still be a need for such proteins to be delivered to the desired site in a suitable matrix.

Disclosed are compositions containing collagen and various forms of calcium phosphate for treatment and bone growth.
Bauer et al., US Pat. No. 5,338,772, discloses a composite material comprising calcium phosphate ceramic particles and a bioabsorbable polymer, wherein the calcium phosphate ceramic is at least 50% by weight and the particles are connected by a polymer bridge. Yes. It is disclosed that the calcium phosphate ceramic particles have a size of about 20 μm to about 5 mm.

Piez et al., US Pat. No. 4,795,467, discloses a composition comprising calcium phosphate mineral particles mixed with atelopeptide reconstituted fiber collagen. The calcium phosphate mineral particles are disclosed as having a size in the range of 100-2,000 μm.
Sauk et al., Patent 4,780,450, discloses a bone repair composition comprising granular polycrystalline calcium phosphate ceramic, phosphorin calcium salt and type I collagen in a mass ratio of 775-15: 3 to 0.1: 1. To do. The ceramic particles are disclosed as dense hydroxyapatite having a diameter of about 1-10 μm or larger dense hydroxyapatite ceramic particles having a diameter greater than about 100 μm.

  Ammann et al., PCT application WO94 / 15653, discloses a formulation comprising tricalcium phosphate (TCP), TGF-β, and optionally collagen. TCP is disclosed as a delivery vehicle for TGF-β such that TCP has a particle size greater than 5 μm, preferably greater than about 75 μm. The most preferred TCP granule size range is disclosed as 125-250 μm.

PCT application WO95 / 08304 discloses hydroxyapatite polymineralic precursor particles mixed with insoluble collagen. The particle size of the polymineral precursor particles is in the range of 0.5 μm to 5 μm. Precursor minerals are converted to hydroxyapatite by hydrolysis, and this process is believed to fuse the minerals to form monolithic hydroxyapatite.
British Patent Specification 1,271,763 of FMC Corporation discloses a complex of calcium phosphate and collagen.

  A tissue repair matrix that is porous, biodegradable, fixed in three dimensions, has shape memory, and structural integrity for a period sufficient to reinforce the post-implantation tissue replacement process And a matrix that maintains porosity.

  The matrix includes mineralized fibrous insoluble collagen, collagen derivatives, or modified gelatin bound to a binder. In one embodiment, the mineral comprises immobilized calcium phosphate within the matrix. The resulting product is lyophilized, crosslinked, dried and sterilized to form a porous matrix. This matrix can be used as a delivery vehicle for tissue repair materials and / or biologically active agents. The matrix can be implanted for bone regeneration and retains its porosity and physical integrity for a period longer than 14 days after implantation.

The matrix is produced using water-soluble biosoluble biopolymers such as collagen, collagen derivatives or modified gelatin. When gelatin is used, it can be modified insoluble in an aqueous environment. Collagen can be derived from a mineralized or non-mineralized collagen source, usually non-mineralized collagen. Therefore, the collagen bone, tendons, skin, etc., preferably be derived from type I collagen containing a combination of two alpha ₂ strands and one α1 collagen chains. Collagen is a young resource, such as calves, or can come from a mature source, such as 2 or 3 year old cattle. The collagen source may be a convenient animal source, mammal or bird, and may be a cow, pig, horse, chicken, turkey, or other domestic collagen source. The insoluble collagenous tissue used is usually dispersed in the medium at high pH values using at least about pH 8, usually about pH 11-12. Sodium hydroxide is generally used, but other hydroxides such as other alkali metal hydroxides or ammonium hydroxide may be used.

Natural collagen may be used in the present invention. Natural collagen includes a region that does not have a triglycine sequence at the end. These regions (telopeptides) are believed to be responsible for the immunogenicity associated with most collagen formulations. Immunogenicity is mitigated by digestion of these regions with proteolytic enzymes such as trypsin and pepsin to produce atelopeptide-collagen.
The concentration of collagen relative to mineralization is generally in the range of about 0.1-10% by weight, more usually about 1-5% by weight. Collagen medium is generally a base concentrate in the range of about 0.0001 to 0.1N. The pH is generally maintained during the reaction in the range of about 10-13, preferably about 12.
Insoluble fibrillar collagen is preferably used and can be prepared by conventional means. Typically this can be accomplished by first mixing with isopropanol (IPA), diethyl ether, hexane, ethyl acetate, or other suitable solvent and then separating the collagen. The pH was typically lowered to about 3, then cooled at about 4 ° C. and expanded. The resulting slurry may be homogenized until the desired viscosity is reached.

  The homogenized slurry is mixed with the solvent and stirred to raise the pH to about 7. To produce mineralized fibrillar collagen, purified insoluble collagen fibrils were homogenized and controlled with calcium chloride (typically 0.05 m) and tribasic sodium phosphate (typically 0.03 m). A reactor introduced at a stirring speed may be used. Sodium hydroxide is used to adjust the pH to 11.0 ± 0.5 when needed during this step. After mineralization, the collagen is rinsed with deionized water or phosphate buffer, mixed with a binder, and the pH is adjusted to within the range of 8.0 ± 2.0. A method for adding phosphate and calcium ions is described in US Pat. No. 5,231,269.

  The calcium phosphate may contain other ions such as carbonate, chloride, fluoride, sodium or ammonium. The presence of carbonate results in a product having the properties of darlite (carbonated hydroxyapatite), while fluoride provides a product having the properties of fluoridated apatite. The mass% of carbonate usually does not exceed 10, but the mass% of fluoride usually does not exceed 2 and is preferably in the range of 0-1. These ions may be present with calcium and / or phosphate sources so long as the ions are compatible and do not cause precipitation in the reaction solution.

The rate of addition of calcium and phosphate ions is typically about 1 hour and at most about 72 hours to obtain a particle size of about 5 microns or less. In general, the addition time ranges from about 2 to 18 hours, usually from about 4 to 16 hours. Mild temperatures are used, usually below about 40 ° C, preferably in the range of about 15 ° C to 30 ° C. The mass ratio of collagen to calcium phosphate mineral is generally about 20: 1 to 1: 1, typically about 7: 3.
Other additives such as non-collagenous proteins, factors or drugs, such as BMP, TGF-β, calcitonin, antibiotics, are formulated into the matrix by adding them to the collagen slurry before or after the addition of calcium and phosphate. May be. The amount of such additives ranges from about 0.0001 to 2% by weight based on biopolymers commonly used as matrices, such as collagen.

The amount of collagen present in the mineralized product will be about 95% to 30% based on the mass of collagen fibers excluding the binder.
Mineralized biopolymer fibers are mixed with a binder to form a porous, shape-memory, three-dimensional fixed tissue repair matrix.
Preferably, the purified soluble collagen is used as a binder by first mixing the soluble collagen with a solvent, such as isopropanol (IPA), and separating the collagen. When the pH is lowered to about 3.0 and the collagen is dissolved, the pH is raised to 5.0 and washed twice with a solvent, rinsed with deionized water, sieved and lyophilized.

  Other binders that can be used are gelatin, polylactic acid, polyglycolic acid, copolymers of lactic acid and glycolic acid, polycaprolactam, carboxymethylcellulose, cellulose esters (eg methyl and ethyl esters), cellulose acetate, glucose, dextran, Examples include, but are not limited to, chitosan, hyaluronic acid, ficol, chondroitin sulfate, polyvinyl alcohol, polyacrylic acid, polypropylene glycol, polyethylene glycol, water-soluble methacrylate or acrylate polymer.

To prepare the porous matrix, the preferred soluble collagen binder is added to the mineralized biopolymer slurry and mixed. Preferably, the insoluble collagen is a biopolymer and a ratio of about 10% (wt: wt) soluble collagen to insoluble collagen is used. The pH is adjusted to 8.0 ± 2.0 as needed. When the desired mixing level is obtained, the dispersion is frozen at -20 ° C to -80 ° C.
The frozen slurry is lyophilized. The porous matrix may be cross-linked to increase physical stability, to increase the absorption time of the matrix, and to simplify the handling of the final product. The lyophilized matrix is preferably cross-linked using glutaraldehyde in solution (typically 0.01%) or steam. If a solution is used, after removing excess reagent, the matrix is dried by lyophilization.

The porous matrix is also formed by filtering a slurry of mineralized collagen fibers and binder to form a web. Thereafter, the dried web may be cross-linked.
Further porous structures are obtained by mixing biopolymer collagen fibers, binders and leachable particles (soluble salts such as sodium chloride) and / or high vapor pressure solids that can be removed later by sublimation. The slurry can be dried and then the leachable or sublimable particles removed to form a porous structure. The porous matrix may be cross-linked.

Other advantages of the cross-linked matrix include greater implantation residence time and shape retention (without implant degradation). This matrix has shape memory and can be compressed from its initial size, shape and porosity, and can return from its compressed state to its initial size, shape and porosity. Furthermore, this can occur without substantial loss of fiber or binder. This matrix will maintain porosity in physical integrity even more than about 14 days after implantation, especially when used for bone growth.
Other crosslinking methods and crosslinking agents such as formaldehyde, chromium salts, diisocyanates, carbodiimides, difunctional acid chlorides, difunctional anhydrides, difunctional succinimides, dibromoisopropanol, epichlorohydrin, diepoxides, dihydrothermal crosslinking UV radiation when dry, or E-beam or gamma radiation in aqueous solution may also be used.
Stabilization of the final product can be obtained by using gamma radiation, E-beam radiation, dry heat or ethylene oxide.

An advantage of the present invention is that the collagen fibers and the immobilized calcium phosphate mineral form a matrix that is particularly advantageous for bone replacement or augmentation. This matrix, in the case of bone exchange, maintains physical integrity and its porosity for a period longer than about 14 days after implantation in a physiological environment. Physical integrity means that the matrix further maintains its porosity, which is important for the tissue exchange or augmentation process. Furthermore, the matrix also has the shape memory described above. This is advantageous in that the matrix can be compressed into a delivery vehicle, such as a cannula, and the delivery vehicle can be introduced at the site of desired tissue growth. By releasing the matrix from the delivery vehicle at that site, the matrix returns to its initial size, shape and porosity without substantial loss of its fibers and binder. This is in contrast to compositions that collapse into amorphous, non-porous masses and lose minerals immediately or immediately after implantation.
The matrix of the present invention is ultimately biodegraded or absorbed and porosity and physical integrity cannot be maintained for a limited period of time. This process usually depends on the size of the matrix to be implanted, of course on average about 2-12 weeks. However, the rate of biodegradation is sufficient as long as complete resorption or biodegradation of the matrix does not occur prior to the bone replacement or augmentation step.

  It is a feature of the present invention that the calcium phosphate mineral, typically present as hydroxyapatite, is immobilized on the matrix as opposed to being free to move through the matrix. The calcium phosphate mineral of the present invention is known to be fixed within the matrix. The cellular response can change in that phagocytic cells such as giant cells and macrophages are more prevalent around the particulate material and often form granulomas. Particles that are small enough to be phagocytosed and sized below about 3-5 μm (microns) are further engulfed by phagocytic cells that stimulate localized tissue reactions. For example, during bone healing, particulate wear debris associated with artificial joints are found in macrophages in adjacent tissues and may be related to increased bone resorption in animal models in a dose-dependent manner. Observed (“Macrophage / particle interactions: effect of size, composition, and surface area”, Shanbhag AS et al., J. Biomed. Mater. Res. 28 (1), 81-90 (1994)). Therefore, it is an advantage of the present invention that the immobilized calcium phosphate mineral is released over time as particles of 5 μm (microns) or less, which is the ideal size absorbed by phagocytic cells. Furthermore, it is a further advantage of the present invention that the release of calcium phosphate mineral is controlled, which is the result of minerals immobilized in the matrix. The advantages of particle size and immobilization are shown in Example 3 below.

  The matrix material has applications as spinal fusion, bone defect filling, fracture repair and tissue or cartilage repair for transplanted periodontal defects, or as an osteosynthesis material. Bone induction and bone growth by combining the compositions of the present invention with osteogenic substances such as autogenous or autogenous aspirate bone marrow, or osteoinductive bone growth factor, BMP, calcitonin or other growth factors Can be further increased. Furthermore, the composition of the invention may contain other additives such as drugs, in particular antibiotics. Furthermore, the matrix provides a substrate to which growth factors can bind, and factors created by the host or introduced externally gather in the matrix. The compositions of the present invention find application in tissue or cartilage repair, fracture repair, maxifacial reconstruction, spinal fusion, indirect reconstruction, and other orthopedic applications.

  The following examples are provided for illustrative purposes, and are not intended to limit the scope of the invention in any way.

Implantation in bone The mineralized collagen matrix according to the invention is implanted in a defect made in the parietal bone of an 8-week-old rat. Histological evaluation is performed on days 14 and 28. After 14 days, bone growth from the cut end of the defect to the collagen matrix is observed. Newly formed fibrous bone surrounds the remaining pieces of matrix and areas of loose connective tissue that are clearly vascularized. By day 28, significant remodeling has occurred and bone cells are present throughout the new bone. The connective tissue cavity seen on day 14 decreased in size as bone growth continued.

Bone Marrow or Autogenous Graft Bone Transplantation The calcium phosphate mineralized collagen matrix from Example 1 was implanted and the bone marrow was added to mature male New Zealand white rabbits (3.7-4.1 kilograms). An incision was made at the midline on the anterior middle surface of the right forearm to expose the ribs. A critical defect was made by removing a 1.5 centimeter piece of ribs using an air drill. During bone cutting, water was flushed to minimize overheating and damage to the bone. This defect was filled with mineralized collagen matrix mixed with bone marrow or autogenous graft. Bone marrow was aspirated from the tibia of the same animal. The autogenous graft was cancellous bone collected from the iliac crest similar to modern bone augmentation or grafting processes. After surgery, the animals were observed daily and radiographic pictures of the operated ribs were taken every 2 weeks for the first 8 weeks and monthly until the 12th week of autopsy. Rabbits were planned to survive 12 and 24 weeks after surgery.

At necropsy, the right and left ribs were removed, and the operated ribs were evaluated for overall signs of healing (callus formation and fusion). Assessments included the presence of bone that showed union or the presence of cartilage, soft tissue, or cracks within the defect that showed possible unstable union.
The ribs were then fixed in 10% neutral buffered formalin and processed for histological and morphometric evaluation.
Radiographic photographs taken at 0, 2, 4, 6, 8, and 12 weeks showed a strong healing response two weeks earlier, the defect site improved and continued to rebuild the natural cortex of the ribs. The observed healing healing is consistent between the treated group calcium phosphate collagen matrix and the control group autograft. There was little difference in radiographic fusion between the two bridging groups.
In initial studies, it was found that empty or untreated defects (negative controls) contained little or no new bone. In this study, autografts (positive controls) formed stable bone healing. Defects including bone marrow treated with calcium phosphate collagen further showed stable cross-linking with new bone compared to that seen with autografts.

Comparative Experiment A calcium phosphate mineral batch was prepared without the addition of collagen. This mineral was collected, washed, and lyophilized to a dry powder. The infrared spectrum showed that it was characteristic of hydroxyapatite.
A mixed matrix was prepared by mixing insoluble fibrillar collagen fibers with soluble collagen in a 9/1 weight ratio with 4 wt% total solids. This slurry was mixed by hand and free mineral was added to form 25% by weight of total solids. The slurry was poured into a 5.08 cm (2 inch) square flat Teflon mold to a depth of about 5 mm, frozen at -80 ° C. and lyophilized. The dried matrix was cross-linked using glutaraldehyde for 30 minutes, washed and lyophilized. The resulting matrix was approximately 4 mm thick, and 8 mm diameter punched samples were made from the matrix for implantation. For comparison, a 8 mm diameter punched implant was prepared using a recently prepared batch of mineralized collagen (immobilized mineral) containing 28 wt% ash.
Implants were placed subcutaneously in the pectoral fascia and two implant materials of the same type were placed bilaterally in 4 rats on days 3, 7 and 14 at the time of implantation. At necropsy, the implants were evaluated for tissue reaction and tissue blocks were obtained for histology. H & E stained parts of the implant and examined surrounding tissue in each animal at each time point to characterize tissue response and tissue integrity.
Observation at autopsy

  Clinical observations at necropsy show a greater inflammatory response and degradable effect in the mixed formulation compared to immobilized mineralized collagen in the rat subcutaneous implant model. Observation shows a weak implant on day 3. As observed histologically, on days 7 and 14, a thickened implant was observed, possibly due to the dramatic fibrous capsule response of the mixed formulation. Formulations with immobilized minerals showed clear surrounding tissue and normal implant appearance at three time points in comparison.

Histological examination shows that the combined formulation results in high levels of acute and chronic inflammation, as indicated by slow (14 days) PMN activity and early (3 days) giant cell activity. Giant cells show that phagocytic activity is probably organized into large amounts of loosely bound mineral particles. Fibroblast invasion was further observed and tissue necrosis was not evident.
In contrast, formulations with mineral particles immobilized on collagen fibers show a typical implant-tissue reaction. At the third day, acute inflammation was observed, which resulted in a rapid chronic transplant response on day 7, a mild inflammation during fibroblast invasion, and neovascularization around the implant . On day 14, signs of increased inflammation are visible, indicating that the added minerals are probably released from the collagen fibers due to collagen degradation.

  A blended formulation of collagen and hydroxyapatite mineral composition exhibits a marked acute inflammatory response in subcutaneous rat implants. Immobilization of mineral components in the mineralized collagen composition reduces mineral bioavailability while reducing inflammation while continuing to support fiber integration during wound healing.

Transplantation at the soft tissue site The mineralized collagen matrix of the present invention was implanted into the subcutaneous tissue of 5-6 week old male SD rats and evaluated after 4 and 8 weeks by histological methods. After 4 weeks, ingrowth of fibrous tissue into the oval mass of the eosinophilic implant was observed. Significant chronic responses were observed from moderate to moderate with lymphocyte infiltration. Peripheral dense fibrous tissue and multinucleated giant cells were present. The appropriate amount of mineralized collagen implant remained at this point. At 8 weeks, the mineralized collagen implant showed a delicate and dense fibrous structure and small voids. Mild inflammation, mainly in the periphery, was observed with chronic inflammatory cell infiltrates and scattered meganuclear cells. Three of the six samples showed a small amount of residual implant material, while the remaining three implant sites contained only trace amounts of implant.

Residence Time of Implanted Mineralized Collagen Matrix The mineralized collagen matrix of the present invention combined with autologous bone marrow and was implanted into a 1.5 cm fragment defect of the ribs of a New Zealand white rabbit. After 12 weeks, the implant site was evaluated histologically and residual mineralized collagen matrix was present in close proximity to the bone matrix.

Release of MP52 The mineralized collagen matrix of the present invention was hydrated with morphogenic protein-52 (MP52) at a concentration of 0.1 mg MP52 / cc matrix. The hydrated matrix was lyophilized. The lyophilized matrix was placed in PBS at 37 ° C. and the release of MP52 from the matrix was measured. At the following time points, 15 minutes, 30 minutes, 1 hour and 18 hours, the cumulative release was 5%, 7%, 9% and 10%, respectively. After 18 hours, 90% loaded MP52 was recovered from the matrix.

Antibiotic Release The mineralized collagen matrix of the present invention was hydrated with vancomycin at a concentration of 10 mg vancomycin / cc matrix. The hydrated matrix was lyophilized. The lyophilized matrix was placed in PBS at 37 ° C. and the release of vancomycin from the matrix was measured. At the following time points, 6 hours, 24 hours, 51 hours, 73 hours, and 97 hours, the cumulative releases were 40%, 63%, 72%, 80%, and 83%, respectively.

Shape Memory The mineralized collagen matrix of the present invention can be easily hydrated by placing the matrix in a fluid. After hydration, this matrix maintains its integrity and shape. The hydrated matrix can be compressed and manually inserted through a narrow hole, but upon rehydration it will return to its original size and shape. During operation and compression, this matrix maintains its integrity without any substantial loss of fiber.

Several embodiments of the present invention are described below.
1. Implantable, porous, and biodegradable, shape-memory three-dimensional anchored matrix, a network of water-insoluble mineralized biopolymer fibers, drugs, and crosslinks And a water-soluble binder that becomes insoluble by the matrix.
2. About 14 days after transplantation into a physiological environment where bone growth is required in a three-dimensionally fixed matrix that is implantable and porous for bone growth and biodegradable A three-dimensionally fixed matrix having a shape memory that maintains its porosity for a long period of time, comprising an insoluble and mineralized biopolymer fiber, a drug, and a water-soluble binder that becomes insoluble by crosslinking A matrix characterized by that.
3. 3. The matrix according to claim 1 or 2, wherein the matrix is compressible from its initial size, shape and porosity, and returns from the compressed state without substantial loss of the fibers or binder.

4). 3. The matrix according to 1 or 2 above, wherein the drug is an antibiotic.
5. The matrix according to 1 or 2 further comprising a growth factor.
6). The matrix according to 1 or 2 further comprising bone marrow.
7). The binder is soluble collagen, gelatin, polylactic acid, polyglycolic acid, a copolymer of lactic acid and glycolic acid, polycaprolactam, carboxymethylcellulose, cellulose ester, dextrose, dextran, chitosan, hyaluronic acid, ficoll, chondroitin sulfate, polyvinyl alcohol, 3. The matrix according to 1 or 2 above, which is selected from the group consisting of polyacrylic acid, polypropylene glycol, polyethylene glycol, water-soluble polyacrylate and water-soluble polymethacrylate.
8). 3. The matrix according to 1 or 2 above, wherein the biopolymer comprises fibrillar collagen.

9. 3. The matrix according to 1 or 2 above, wherein the mineral is made of hydroxyapatite.
10. 3. The matrix according to 2 above, wherein the mineral is released into the physiological environment while replacing bone with sustained release that maintains the porosity.
11. 3. The matrix according to 1 or 2 above, wherein the mineralized biopolymer fiber takes the form of mineralized collagen containing about 30 to 95% by mass of collagen.
12 Furthermore, the matrix of said 1 or 2 containing an autogenous bone.
13. A method of repairing fibrous or cartilage tissue, which is a three-dimensionally fixed, porous and biodegradable, shape memory with an effective amount sufficient to promote the formation of new fibrous or cartilage tissue A method comprising introducing a composition comprising a matrix to a target site for repair, wherein the matrix comprises a mineralized biopolymer fiber and a water-soluble binder that becomes insoluble by crosslinking.

14 A method for repairing fibrous tissue, cartilage tissue or bone, comprising the following steps:
(a) introducing a delivery vehicle to a target site for repair, wherein the vehicle comprises a three-dimensional fixed matrix that is porous and biodegradable and has shape memory, Including an insoluble mineralized biopolymer fiber and a water-soluble binder that becomes insoluble by crosslinking in a compressed state with respect to the initial size, shape and porosity of the matrix; and
(b) releasing the matrix from the delivery vehicle so that the matrix returns to the initial size, shape and porosity;
Including methods.
15. 15. The method of claim 13 or 14, wherein the matrix reverts to the size, shape and porosity without substantial loss of the fibers and binder.
16. 15. The method according to 13 or 14 above, wherein the matrix further comprises an additive.
17. The method according to 16 above, wherein the additive comprises a drug.
18. 18. The method according to 17 above, wherein the drug comprises an antibiotic.
19. The method according to 16 above, wherein the additive comprises a growth factor.
20. 15. The method according to 13 or 14 above, wherein the matrix further comprises bone marrow.

21. The binder is soluble collagen, gelatin, polylactic acid, polyglycolic acid, a copolymer of lactic acid and glycolic acid, polycaprolactam, carboxymethylcellulose, cellulose ester, dextrose, dextran, chitosan, hyaluronic acid, ficoll, chondroitin sulfate, polyvinyl alcohol, 15. The method according to 13 or 14 above, which is selected from the group consisting of polyacrylic acid, polypropylene glycol, polyethylene glycol, water-soluble polyacrylate and water-soluble polymethacrylate.
22. 15. The method according to 13 or 14 above, wherein the biopolymer comprises fiber collagen.
23. 15. The method according to 13 or 14 above, wherein the mineral of the mineralized biopolymer fiber comprises hydroxyapatite.
24. 15. The method of claim 13 or 14, wherein the matrix comprises collagen and immobilized calcium phosphate in the form of mineralized collagen containing about 30-95% by weight collagen.
25. 15. The method according to 13 or 14 above, wherein the matrix further comprises autogenous bone.
26. The method according to 21 above, wherein the binder comprises soluble collagen.

Claims (12)

Use of a three-dimensionally fixed matrix that has a shape memory and is porous and biodegradable, wherein the matrix is insoluble and mineralized biopolymer fibers and water that becomes insoluble by crosslinking. A soluble binder and is in compression with respect to the initial size, shape and porosity of the matrix, the matrix comprising the following steps:
(a) introducing a delivery vehicle comprising the matrix into a target site for treatment; and
(b) releasing the matrix from the delivery vehicle so that the matrix returns to the initial size, shape and porosity;
For the manufacture of a medicament for the treatment of damaged or defective fibrous or cartilage tissue.   Use according to claim 1, wherein the matrix returns to the size, shape and porosity without a substantial loss of the fibers and binder.   The use according to claim 1, wherein the matrix further comprises an additive.   The use according to claim 3, wherein the additive comprises a drug.   Use according to claim 4, wherein the drug consists of antibiotics.   4. Use according to claim 3, wherein the additive consists of a growth factor.   The use according to claim 1, wherein the matrix further comprises bone marrow.   The binder is soluble collagen, gelatin, polylactic acid, polyglycolic acid, a copolymer of lactic acid and glycolic acid, polycaprolactam, carboxymethylcellulose, cellulose ester, dextrose, dextran, chitosan, hyaluronic acid, ficoll, chondroitin sulfate, polyvinyl alcohol, Use according to claim 1, selected from the group consisting of polyacrylic acid, polypropylene glycol, polyethylene glycol, water-soluble polyacrylate and water-soluble polymethacrylate.   The use according to claim 1, wherein the biopolymer comprises fiber collagen.   The use according to claim 1, wherein the mineral of the mineralized biopolymer fiber comprises hydroxyapatite.   The use according to claim 1, wherein the matrix comprises collagen and immobilized calcium phosphate in the form of mineralized collagen comprising about 30-95% by weight collagen.   Use according to claim 8, wherein the binder consists of soluble collagen.