CN100335141C - Method for preparing bionic multi-layered structure cartilage implant material - Google Patents

Abstract

The invention provides a method for preparing a bionic multilayer structure cartilage implant material, which belongs to the technical field of biomedical materials or biocomposite materials. The process includes: preparation of lubricating layer, preparation of bioactive layer, preparation of multi-layer structure hydrogel, injecting PVA/bioactive component composite solution into a cylindrical or rectangular mold, then injecting PVA solution, applying pressure for compaction; injecting PVA The lubricating layer solution is pressurized and compacted; the above-mentioned mold is placed in a refrigerator at -10 to -40°C, and subjected to repeated freezing-melting for 2 to 8 times to obtain a bionic multi-layer structure cartilage implant material. The advantages are: the surface layer of the obtained cartilage implant material is a wear-resistant lubricating layer, the middle layer is a stress-bearing layer, and the bottom layer is a bone biologically active connecting layer. When rubbing without water, the surface friction coefficient is less than 0.1, and the elastic modulus is greater than 15MPa. The performance of natural cartilage, while meeting the high biomechanical performance requirements of cartilage implant materials, endows it with excellent surface lubricity and bioactive connectivity.

Description

A preparation method of a bionic multi-layer cartilage implant material

technical field

The invention belongs to the technical field of biomedical materials or biocomposite materials, and in particular provides a method for preparing a bionic multilayer structure cartilage implant material.

Background technique

In organisms, cartilage tissue bears the load of bone conduction, can absorb shocks, buffers extrusion stress and shear stress, and reduces friction and wear during articular surface movement. Cartilage is composed of chondrocytes and matrix. Normal mature chondrocytes have slow metabolism and low growth and differentiation ability. Once cartilage tissue is damaged or diseased, its self-repair and self-healing capabilities are extremely limited, and articular cartilage must be repaired and transplanted. Cartilage tissue disease is a common phenomenon in clinical orthopedic surgery. According to statistics, there are about 100,000 patients with joint disease caused by cartilage disease in my country every year. At present, the clinical treatment of articular cartilage mainly adopts autologous or allogeneic cartilage transplantation and joint prosthesis replacement. However, allogeneic cartilage transplantation has problems such as limited donor sources, potential infectious viruses, and immune rejection. Artificial cartilage materials and implants that replace the function of cartilage to meet the needs of articular cartilage treatment.

At present, the artificial cartilage materials that have been studied more mainly include metal-ultra-high molecular weight polyethylene anti-friction joint prosthesis, silicone rubber, polyurethane joint cushion material, polyvinyl alcohol hydrogel, etc. Although these cartilage prostheses can replace cartilage to a certain extent, they still have shortcomings such as easy wear and loosening, poor interface lubrication, and lack of biological activity. Especially in the singleness of composition and structure, it is difficult to truly replace cartilage. Function. For example, high crystallinity polyvinyl alcohol hydrogel elastomers can be obtained by radiation crosslinking and freeze-melt crosslinking, which have excellent strength, elasticity and ductility, as well as good biocompatibility and high water content. , microporous tissue and water permeability, its physical and chemical properties and biological properties are closer to biological tissue than other synthetic materials, and it is an ideal cartilage replacement material. However, PVA hydrogel has a smooth surface and no biological activity. When it is implanted into the joint as a cartilage prosthesis, it has poor bonding performance with the bone base, which affects the fixation and repair function of cartilage. We use PVA and bioactive hydroxyapatite to combine To solve this problem (the relevant technology has been authorized by the national invention patent), but at the same time bring about the problem of the decrease of PVA lubricity; and the existing methods for improving the surface lubricity of cartilage prosthesis may decrease its biomechanical properties. How to endow cartilage implant materials with high biomechanical properties and at the same time make them have excellent surface lubricity and bioactive connectivity is a problem that has not been solved at home and abroad.

It is well known that mature articular cartilage can be divided into superficial, middle, deep and calcified layers according to structural and functional changes. Among them, the cells in the superficial layer are spindle-shaped, the long axis is parallel to the articular surface, and the collagen fibers are arranged in the tangential direction, which mainly bear the shear load and lubrication; the chondrocytes in the middle and deep layers gradually become oval, round, and even columnar. Collagen fibers are thick and vertically arranged, and mainly bear the compressive load; the calcified matrix of the calcified layer and some longitudinal fibers in the deep layer play the role of firmly fixing the articular cartilage surface to the subchondral bone. Its different levels of structure and function ensure the biomechanical properties and physiological functions of cartilage. For this reason, according to the structure of natural cartilage, the present invention proposes a preparation method of a novel bionic multilayer structure cartilage implant material whose surface layer is a wear-resistant lubricating layer, the middle layer is a stress layer, and the bottom layer is a bone bioactive connecting layer.

Contents of the invention

The purpose of the present invention is to provide a method for preparing a bionic multi-layer structure cartilage implant material, through which a bionic bionic layer in which the surface layer is a wear-resistant lubricating layer, the middle layer is a stress-bearing layer, and the bottom layer is a bone bioactive connecting layer can be obtained. The multi-layer structure composite hydrogel artificial cartilage implant material fundamentally solves the problem that the existing hydrogel cartilage materials are difficult to meet lubricity, bioactivity and biomechanical properties at the same time, making the artificial cartilage material comparable in structure and function. Natural cartilage is closer.

The preparation process of the present invention is as follows:

a. After refining the analytically pure polyvinyl alcohol (PVA), dissolve it in double distilled water in a constant temperature water bath of 85～95°C or in a pressure cooker of 110～150MPa, prepare a homogeneous aqueous solution (solution I) with a concentration of 15～30% by weight ).

B, preparation of lubricating layer: add polyvinylpyrrolidone (PVP), chitosan, hyaluronic acid or sodium hyaluronate (HA) respectively in PVA aqueous solution, wherein the addition of polyvinylpyrrolidone and chitosan is 5% of PVA weight ～40%, chitosan should be dissolved in 0.1～20% dilute acid solution for 2～48 hours and then added to PVA solution; The concentration in the PVA solution is 0.1-3% by weight. After the above mixed solution is fully stirred at 85-95°C, it is left to stand for 12-48 hours or vacuum exhausted for 2-8 hours until the bubbles are completely removed (solution II).

c. Preparation of bioactive layer: use hydroxyapatite, coral hydroxyapatite, β-tricalcium phosphate, bioactive glass, and allogeneic bone particles or blocks to compound with PVA aqueous solution, and one of the following methods can be used (1) Grind hydroxyapatite, coral hydroxyapatite, β-tricalcium phosphate, bioactive glass, and allogeneic bone to less than 30 μm respectively, and add them to PVA aqueous solution at 85-95°C. The content is 5-20% of the weight of PVA, and it is treated with an ultrasonic disperser for more than 1-5 hours to obtain a uniform suspension solution III. (2) Add the calcium ethylate solution with a weight percentage concentration of 2% to 20% into the PVA solution under vigorous stirring; prepare a H ₃ PO ₄ absolute ethanol solution with a Ca/P ratio of 1.0 to 3.0, shake and stir evenly Finally, slowly add it dropwise into the above-mentioned PVA solution, stir and react fully to obtain a PVA/nano-hydroxyapatite or PVA/nano-tricalcium phosphate composite solution (solution III). (3) Cut porous hydroxyapatite, coral hydroxyapatite, β-tricalcium phosphate, bioactive glass and allogeneic bone into cubes or cylinders, and place them in a mold with a piston , inject the PVA solution and use the piston action to completely fill it into the porous material to obtain a liquid-solid composite mixed solution (Solution III).

d. Preparation of multi-layer structure hydrogel: inject solution III into a cylindrical or rectangular mold with a thickness of 0.1-10 mm, and apply a pressure of 0.1-10 MPa for compaction; then inject solution I with a thickness of 1-20 mm; apply pressure Compaction: Inject solution II with a thickness of 0.05-5 mm, pressurize and compact.

e. Put the mold above into a refrigerator at -10 to -40°C, freeze for 3 to 24 hours, then melt at 15 to 40°C for 2 to 10 hours, and repeat freezing and melting for 2 to 8 times to obtain a bionic Multilayer structural cartilage implant material.

Compared with the prior art, the present invention has the following advantages and beneficial effects:

By adopting the preparation method provided by the present invention, a new type of bionic multi-layer structure cartilage implant material can be obtained, the surface layer is a wear-resistant lubricating layer, the middle layer is a stress layer, and the bottom layer is a bone bioactive connecting layer, which is similar to the structure and structure of natural cartilage. The functions are similar, and its different levels of structure and function ensure the biomechanical properties and physiological functions of cartilage. The surface friction coefficient of the cartilage implant material obtained by this method can be less than 0.1 and the elastic modulus can be greater than 15MPa when it is rubbed without water. , reaching or even surpassing the performance of natural cartilage; after 8 weeks of implanting animal cartilage, it can be observed that there is bone tissue growing into the cartilage implant, that is, the cartilage material and the bone base have formed a firm bony connection, and the cartilage implant has been satisfied. While meeting the high biomechanical performance requirements of the material, it also endows it with excellent surface lubricity and bioactive connectivity. In addition, the multi-layer material obtained by the method is tightly bonded between the layers, and there is no obvious boundary or peeling between the layers before the main body material is destroyed, and has good structure and performance stability.

Detailed ways

Example 1

a. After refining the analytically pure polyvinyl alcohol (PVA), prepare a homogeneous aqueous solution (solution I) with a concentration of 15% by weight in a 90° C. constant temperature water bath.

b. Preparation of lubricating layer: Add polyvinylpyrrolidone (PVP) to the PVA aqueous solution, the addition amount is 10% of the PVA weight, after the mixed solution is fully stirred at 90°C, let it stand for 24 hours until the bubbles are completely eliminated to obtain solution II .

c. Preparation of biologically active layer: Grind coral hydroxyapatite to below 30 μm, add it to 90°C PVA aqueous solution, the content of coral hydroxyapatite is 10% of the weight of PVA, and treat it with an ultrasonic disperser for 3 hours to obtain a uniform Suspension solution III.

d. Preparation of multilayer structure hydrogel: inject solution III into a cylindrical or square mold with a thickness of 1 mm, and apply a pressure of 0.3 MPa for compaction; then inject solution I with a thickness of 2 mm; apply pressure for compaction; inject the solution II, the thickness is 0.5mm, pressurized and compacted.

e. Put the mold above into a refrigerator at -20°C, freeze for 6 hours, then melt at 25°C for 8 hours, and repeat freezing and melting for 4 times to obtain a bionic multi-layer cartilage implant material.

Example 2

a. After refining the analytically pure polyvinyl alcohol (PVA), prepare a homogeneous aqueous solution (solution I) with a concentration of 30% by weight in a constant temperature water bath at 95°C.

b. Preparation of lubricating layer: after dissolving chitosan in 0.5% dilute acetic acid solution for 24 hours, add it to the PVA solution. The amount of chitosan added is 8% of the weight of PVA; after fully stirring the mixed solution at 95°C , evacuated for 6 hours until the air bubbles were completely removed to obtain solution II.

c. Preparation of bioactive layer: Grind the bioactive glass to below 30 μm, add it to 95° C. PVA aqueous solution, its content is 15% of the weight of PVA, and treat it with an ultrasonic disperser for more than 5 hours to obtain a uniform suspension solution III.

d. Preparation of multilayer structure hydrogel: inject solution III into a cylindrical mold with a thickness of 3 mm, and apply a pressure of 3 MPa for compaction; then inject solution I with a thickness of 5 mm; apply pressure for compaction; inject solution II with a thickness of 5 mm 1mm, pressurized and compacted.

e. Put the above-mentioned mold in a refrigerator at -30°C, freeze for 4 hours, then melt at 30°C for 10 hours, and repeat freezing-melting 6 times to obtain a bionic multi-layer structure cartilage implant material.

Example 3

a. After refining the analytically pure polyvinyl alcohol (PVA), dissolve it in double-distilled water in a 125MPa pressure cooker to prepare a homogeneous aqueous solution (solution I) with a concentration of 20% by weight.

b. Preparation of lubricating layer: dissolve hyaluronic acid (HA) in physiological saline to prepare a homogeneous solution, add it to PVA aqueous solution, and the concentration of HA in the PVA solution is 0.15% by weight. After the above mixed solution was fully stirred at 95°C, it was left to stand for 48 hours until the bubbles were completely removed to obtain solution II.

c. Preparation of biologically active layer: add calcium ethoxide solution with a concentration of 5% by weight into the PVA solution under vigorous stirring; prepare H ₃ PO ₄ absolute ethanol solution with a concentration of H 3 PO 4 according to a Ca/P ratio of 2.0, shake and stir evenly , was slowly added dropwise to the above PVA solution, and the PVA/nano tricalcium phosphate composite solution (solution III) was obtained after the reaction was fully stirred.

d. Preparation of multilayer structure hydrogel: inject solution III into a rectangular mold with a thickness of 5 mm, and apply a pressure of 5 MPa for compaction; then inject solution I with a thickness of 8 mm; apply pressure for compaction; inject solution II with a thickness of 2 mm , pressurized and compacted.

e. Put the mold above into a refrigerator at -20°C, freeze for 10 hours, then melt at 25°C for 8 hours, and repeat freezing-melting 8 times to obtain a bionic multi-layer cartilage implant material.

Example 4

a. After refining the analytically pure polyvinyl alcohol (PVA), dissolve it in double-distilled water in a 115MPa pressure cooker to prepare a 25% homogeneous aqueous solution (solution I) with a weight percent concentration.

b. Preparation of lubricating layer: Sodium hyaluronate (HA) was dissolved in physiological saline to prepare a uniform solution, and then added into PVA aqueous solution, the concentration of HA in PVA solution was 2.5% by weight. After the above mixed solution was fully stirred at 90°C, it was vacuum exhausted for 8 hours until the bubbles were completely removed to obtain solution II.

c. Preparation of bioactive layer: the porous allogeneic bone block is cut into a cube, placed in a mold with a piston, injected with PVA solution and fully filled with the porous material by the action of the piston, to obtain a liquid-solid composite mixed solution ( Solution III).

d. Preparation of multilayer structure hydrogel: inject solution III into a rectangular mold with a thickness of 8 mm, and apply a pressure of 9 MPa for compaction; then inject solution I with a thickness of 15 mm; apply pressure for compaction; inject solution II with a thickness of 5 mm, Pressurize and compact.

e. Put the mold above into a refrigerator at -35°C, freeze it for 20 hours, then melt it at 35°C for 8 hours, and repeat freezing-melting 6 times to obtain a bionic multi-layer cartilage implant material.

Example 5

a. After refining the analytically pure polyvinyl alcohol (PVA), prepare a homogeneous aqueous solution (solution I) with a concentration of 25% by weight in a 95° C. constant temperature water bath.

b. Preparation of lubricating layer: Add polyvinylpyrrolidone (PVP) to the PVA aqueous solution, the addition amount is 20% of the PVA weight, after the mixed solution is fully stirred at 95°C, vacuum pump for 6 hours until the bubbles are completely eliminated to obtain the solution II.

c. Preparation of biologically active layer: Preparation of biologically active layer: add calcium ethoxide solution with a concentration of 5% by weight into the PVA solution under vigorous stirring; prepare H ₃ PO ₄ absolute ethanol solution with a concentration of 1.67 according to the Ca/P ratio After oscillating and stirring evenly, slowly add it dropwise into the above-mentioned PVA solution, and obtain a PVA/nano-hydroxyapatite composite solution (solution III) after fully stirring and reacting.

d. Preparation of multilayer structure hydrogel: inject solution III into a cylindrical mold with a thickness of 4 mm, and apply a pressure of 1 MPa for compaction; then inject solution I with a thickness of 8 mm; apply pressure for compaction; inject solution II with a thickness of 2mm, pressurized and compacted.

e. Put the mold above into a refrigerator at -20°C, freeze for 6 hours, then melt at 30°C for 8 hours, and repeat freezing-melting 4 times to obtain a bionic multilayer cartilage implant material.

Claims (4)

1. A method for preparing a bionic multilayer structure cartilage implant material, characterized in that: the preparation process is: a. Preparation of lubricating layer: after refined analytically pure polyvinyl alcohol PVA is dissolved in double-distilled water in a constant temperature water bath at 85-95°C or in a pressure cooker at 110-150MPa, it is prepared as a uniform aqueous solution with a concentration of 15-30% by weight; Add polyvinylpyrrolidone PVP, chitosan, hyaluronic acid or sodium hyaluronate HA in the PVA aqueous solution, called solution I, wherein the addition of polyvinylpyrrolidone and chitosan is 5 to 40% of the weight of PVA, and the shell Polysaccharides should be dissolved in 0.1-20% dilute acid solution for 2-48 hours before adding to PVA solution; HA should be dissolved in physiological saline to prepare a uniform solution, and then added to PVA aqueous solution, the concentration of HA in PVA solution It is 0.1-3% by weight; after the above mixed solution is fully stirred at 85-95°C, it is left to stand for 12-48 hours or vacuum exhausted for 2-8 hours, until the bubbles are completely eliminated to obtain solution II; b. Preparation of bioactive layer: use hydroxyapatite, coral hydroxyapatite, β-tricalcium phosphate, bioactive glass, and allogeneic bone particles or blocks to compound with PVA aqueous solution to obtain PVA/bioactive components Composite solution, called solution III; c. Preparation of multi-layer structure hydrogel: inject solution III into a cylindrical or rectangular mold with a thickness of 0.1-10 mm, and apply a pressure of 0.1-10 MPa for compaction; then inject solution I with a thickness of 1-20 mm; apply pressure Compaction; inject solution II, the thickness is 0.05-5mm, pressurize and compact; d. Put the mold above into a refrigerator at -10 to -40°C, freeze for 3 to 24 hours, then melt at 15 to 40°C for 2 to 10 hours, and repeat freezing and melting for 2 to 8 times to obtain a bionic multi- Layer structure cartilage implant material. 2. The preparation method according to claim 1, characterized in that the preparation method of the biologically active layer solution III is as follows: separately mix hydroxyapatite, coral hydroxyapatite, β-tricalcium phosphate, bioactive glass and the same Allogeneic bone is ground to less than 30 μm, added to 85-95°C PVA aqueous solution, the content of bioactive components is 5-20% of the weight of PVA, and treated with an ultrasonic disperser for 1-5 hours to obtain a uniform suspension solution III. 3. The preparation method according to claim 1, characterized in that, the preparation method of the biologically active layer solution III is: adding calcium ethylate solution with a concentration of 2% to 20% by weight into the PVA solution under vigorous stirring; The Ca/P ratio is 1.0-3.0 and the concentration of H ₃ PO ₄ absolute ethanol solution is prepared. After shaking and stirring evenly, slowly add it to the above PVA solution. After fully stirring and reacting, PVA/nano hydroxyapatite or PVA/nano Tricalcium phosphate complex solution. 4. The preparation method according to claim 1, characterized in that: the preparation method of the bioactive layer solution III is as follows: separately mix porous hydroxyapatite, coral hydroxyapatite, β-tricalcium phosphate, and bioactive glass Cut the allogeneic bone block into a cube or cylinder, place it in a mold with a piston, inject the PVA solution and completely fill it into the porous material under the action of the piston, and obtain a liquid-solid composite mixed solution.