阅读说明：本技术 一种神经修复支架及其制备方法 (Nerve repair stent and preparation method thereof ) 是由 张鹏 綦磊 于 2019-11-20 设计创作，主要内容包括：本发明公开了一种神经修复支架,其特征在于,由如下重量份的各原料制成：乙烯基改性端羟基聚(乳酸-羟基乙酸75/25)共聚物25-35份、珍珠粉0.2-0.5份、氨基修饰葡聚糖改性羧基化富勒烯0.1-0.3份、氨基修饰葡聚糖改性氧化石墨烯1-4份、致孔剂0.8-2份、脱细胞神经基质3-8份。本发明还公开了所述神经修复支架的制备方法。本发明公开的神经修复支架孔隙率大而孔径均匀,生物相容性好,抗菌消炎性能佳,机械力学性能优异,能够生物降解,具有辅助神经修复功能,可靠性高,临床实用性强。(The invention discloses a nerve repair stent which is characterized by being prepared from the following raw materials in parts by weight: 25-35 parts of vinyl modified hydroxyl-terminated poly (lactic acid-glycolic acid 75/25) copolymer, 0.2-0.5 part of pearl powder, 0.1-0.3 part of amino modified glucan modified carboxylated fullerene, 1-4 parts of amino modified glucan modified graphene oxide, 0.8-2 parts of pore-foaming agent and 3-8 parts of acellular nerve matrix. The invention also discloses a preparation method of the nerve repair scaffold. The nerve repair scaffold disclosed by the invention has the advantages of large porosity, uniform pore diameter, good biocompatibility, good antibacterial and anti-inflammatory properties, excellent mechanical properties, biodegradability, auxiliary nerve repair function, high reliability and strong clinical practicability.)

1. The nerve repair bracket is characterized by being prepared from the following raw materials in parts by weight: 25-35 parts of vinyl modified hydroxyl-terminated poly (lactic acid-glycolic acid 75/25) copolymer, 0.2-0.5 part of pearl powder, 0.1-0.3 part of amino modified glucan modified carboxylated fullerene, 1-4 parts of amino modified glucan modified graphene oxide, 0.8-2 parts of pore-foaming agent and 3-8 parts of acellular nerve matrix.

2. The nerve repair scaffold according to claim 1, wherein the pore-forming agent is at least one of polyethylene glycol, hydroxypropyl cellulose, urea, and polyvinylpyrrolidone.

3. The nerve repair scaffold according to claim 1, wherein the preparation method of the vinyl-modified poly (lactic-co-glycolic acid 75/25) copolymer comprises the following steps: adding a poly (lactic acid-glycolic acid 75/25) copolymer, 3-butenoic acid, 4-dimethylaminopyridine and N, N' -dicyclohexylcarbodiimide into an organic solvent, stirring and reacting for 3-5 hours at 25-35 ℃, then performing rotary evaporation to remove the solvent, washing the product with methanol for 3-5 times, and performing rotary evaporation to remove methanol to obtain the vinyl modified poly (lactic acid-glycolic acid 75/25) copolymer.

4. The nerve repair scaffold according to claim 3, wherein the molar ratio of the poly (lactic-co-glycolic acid 75/25) copolymer to the 3-butenoic acid to the 4-dimethylaminopyridine to the N, N' -dicyclohexylcarbodiimide to the organic solvent is 1:2 (0.3-0.6) to 0.4 (10-15).

5. The nerve repair scaffold according to claim 3, wherein the organic solvent is one of tetrahydrofuran, dichloromethane and acetone.

6. The nerve repair scaffold according to claim 1, wherein the preparation method of the amino-modified glucan-modified carboxylated fullerene comprises the following steps: dispersing MTR carboxylated fullerene in tetrahydrofuran, then adding amino modified glucan and 2-ethoxy-1-ethoxycarbonyl-1, 2-dihydroquinoline, stirring and reacting at 25-35 ℃ for 12-18 hours, and after the reaction is finished, removing the tetrahydrofuran by rotary evaporation to obtain the amino modified glucan modified carboxylated fullerene.

7. The nerve repair scaffold as claimed in claim 6, wherein the mass ratio of MTR carboxylated fullerene, tetrahydrofuran, amino modified dextran and 2-ethoxy-1-ethoxycarbonyl-1, 2-dihydroquinoline is 1 (9-15): 0.8-1.2): 0.2-0.4.

8. The nerve repair scaffold as claimed in claim 1, wherein the preparation method of the amino-modified glucan-modified graphene oxide comprises the following steps: dispersing graphene oxide in tetrahydrofuran, then adding amino modified glucan and an alkaline catalyst, stirring and reacting for 4-6 hours at 80-90 ℃, removing the tetrahydrofuran by rotary evaporation after the reaction is finished, washing a product for 3-6 times by water, and then drying the product in a vacuum drying oven at 85-95 ℃ to constant weight to obtain the amino modified glucan modified graphene oxide.

9. The nerve repair scaffold as claimed in claim 1, wherein the mass ratio of the graphene oxide to the tetrahydrofuran to the amino-modified glucan to the basic catalyst is (3-5): (10-15):1 (0.3-0.5); the alkaline catalyst is at least one of sodium hydroxide, sodium carbonate, potassium hydroxide and potassium carbonate.

10. The nerve repair scaffold according to any one of claims 1-9, wherein the method of making the nerve repair scaffold comprises the steps of: uniformly mixing the raw materials to obtain a mixture, adding ultrapure water with the mass 5-10 times of that of the mixture, dispersing for 15-25 minutes by using ultrasonic, centrifuging for 10-30 minutes at the rotating speed of 2000-5000rmp, removing excessive water to obtain uniform paste slurry, adding the slurry into a mold, drying for 15-40 hours at-80 ℃ by using a freeze dryer, spraying a photoinitiator solution with the mass fraction of 0.2-0.5% on the surface of the obtained material, irradiating for 35-45 minutes under ultraviolet light with the wavelength of 220-260nm, washing the product for 3-5 times by using water, finally placing the product in the freeze dryer, freeze-drying for 30-42 hours at-80 ℃, and irradiating and sterilizing by using cobalt 60 to obtain the nerve repair stent; the photocatalyst solution is an ethanol solution of benzoin.

Technical Field

The invention relates to the technical field of medical instruments, in particular to a nerve repair stent and an ester method thereof.

Background

The nervous system is a functional regulatory system that plays a leading role in the human body and plays a very important role in human life activities. Because of the limited ability of the nervous system to repair after damage, the treatment of nerve damage and degenerative diseases is a major medical problem. Nerve damage, which is often caused by trauma and other conditions, is a type of injury that is common and frequent in clinical practice, often causes sensory and motor dysfunction or loss in patients, and seriously affects the daily lives and tasks of patients. It is very necessary to repair the nerve of the patient.

Among the neural repair protocols, neural scaffold repair is most common. The basic strategy of the scaffold repair of the human nerve is to construct a three-dimensional skeleton with bioactivity in advance in vitro and implant the three-dimensional skeleton into a damaged part of a tissue, and create conditions for the growth of the tissue by simulating an extracellular matrix environment so as to repair the function of the damaged nerve. It can be seen that the repair effect of this nerve repair approach depends largely on the quality of the nerve repair scaffold. The development of the nerve repair scaffold with excellent comprehensive performance is very important.

Currently, there are three types of neural repair scaffold materials: 1. a natural scaffold material; mainly uses autologous or allogeneic nerves, veins, skeletal muscles, amnion and the like, but the materials are difficult to obtain due to limited sources and have the danger of cross transmission of pathogenic microorganisms, so that the mass production is difficult. 2. A natural biological material; mainly comprises collagen, gelatin, chitosan, alginate, cellulose, hyaluronic acid, aminodextran, liposome, acellular extracellular matrix and the like, and the materials mainly have the advantages of good biocompatibility and low antigenicity, and part of the materials have natural pore structure systems, are beneficial to cell adhesion, growth and proliferation, but have poor mechanical properties and lack of sufficient physical strength. 3. A non-biologically active raw material; the prepared tissue engineering nerve scaffold can obtain better physical properties, and the commonly used materials mainly comprise polyglycolic acid, polylactic acid and the like. However, the non-biological active material lacks various biological signals, the cell adhesion is poor, the degradation products also often cause inflammatory reaction locally, and the like.

Patent CN 107823704a discloses a double-layer porous mesh material composed of polyethylene oxide, polyvinyl alcohol, type i collagen, hydroxyapatite and modified sodium alginate, which can repair damaged periodontal tissues, but has relatively poor mechanical strength. Patent CN 107007882a discloses a porous scaffold for nerve repair, which has two states of sheet and tube, but fails to satisfy the growth condition of nerve cell orientation spreading. Patent CN 108187147a discloses an electrospun three-layer stent catheter, which has a response mechanism after electrical stimulation with conductivity, but fails to maintain the spatial position between cells effectively when a plurality of cells are assembled in the biomaterial.

Therefore, the development of the nerve repair scaffold which has the advantages of large porosity, uniform pore diameter, good biocompatibility, good antibacterial and anti-inflammatory properties, excellent mechanical properties, biodegradability and auxiliary nerve repair function meets the market demand and has very important significance for promoting nerve repair.

Disclosure of Invention

In view of the above, the invention aims to provide a nerve repair scaffold and a preparation method thereof, wherein the preparation method is simple and easy to operate, and has high preparation efficiency and high finished product qualification rate; the prepared nerve repair scaffold has the advantages of large porosity, uniform pore diameter, good biocompatibility, good antibacterial and anti-inflammatory properties, excellent mechanical properties, biodegradability, auxiliary nerve repair function, high reliability and strong clinical practicability.

In order to achieve the purpose, the invention adopts the technical scheme that:

the nerve repair bracket is characterized by being prepared from the following raw materials in parts by weight: 25-35 parts of vinyl modified hydroxyl-terminated poly (lactic acid-glycolic acid 75/25) copolymer, 0.2-0.5 part of pearl powder, 0.1-0.3 part of amino modified glucan modified carboxylated fullerene, 1-4 parts of amino modified glucan modified graphene oxide, 0.8-2 parts of pore-foaming agent and 3-8 parts of acellular nerve matrix.

Further, the pore-foaming agent is at least one of polyethylene glycol, hydroxypropyl cellulose, urea and polyvinylpyrrolidone.

Further, the preparation method of the vinyl modified poly (lactic-co-glycolic acid 75/25) copolymer comprises the following steps: adding a poly (lactic acid-glycolic acid 75/25) copolymer, 3-butenoic acid, 4-dimethylaminopyridine and N, N' -dicyclohexylcarbodiimide into an organic solvent, stirring and reacting for 3-5 hours at 25-35 ℃, then performing rotary evaporation to remove the solvent, washing the product with methanol for 3-5 times, and performing rotary evaporation to remove methanol to obtain the vinyl modified poly (lactic acid-glycolic acid 75/25) copolymer.

Preferably, the molar ratio of the poly (lactic acid-glycolic acid 75/25) copolymer to the 3-butenoic acid to the 4-dimethylaminopyridine to the N, N' -dicyclohexylcarbodiimide to the organic solvent is 1:2 (0.3-0.6) to 0.4 (10-15).

Preferably, the organic solvent is one of tetrahydrofuran, dichloromethane and acetone.

Further, the preparation method of the amino-modified glucan modified carboxylated fullerene comprises the following steps: dispersing MTR carboxylated fullerene in tetrahydrofuran, then adding amino modified glucan and 2-ethoxy-1-ethoxycarbonyl-1, 2-dihydroquinoline, stirring and reacting at 25-35 ℃ for 12-18 hours, and after the reaction is finished, removing the tetrahydrofuran by rotary evaporation to obtain the amino modified glucan modified carboxylated fullerene.

Preferably, the mass ratio of the MTR carboxylated fullerene, the tetrahydrofuran, the amino modified glucan and the 2-ethoxy-1-ethoxycarbonyl-1, 2-dihydroquinoline is 1 (9-15): (0.8-1.2): (0.2-0.4).

Further, the preparation method of the amino modified glucan modified graphene oxide comprises the following steps: dispersing graphene oxide in tetrahydrofuran, then adding amino modified glucan and an alkaline catalyst, stirring and reacting for 4-6 hours at 80-90 ℃, removing the tetrahydrofuran by rotary evaporation after the reaction is finished, washing a product for 3-6 times by water, and then drying the product in a vacuum drying oven at 85-95 ℃ to constant weight to obtain the amino modified glucan modified graphene oxide.

Preferably, the mass ratio of the graphene oxide to the tetrahydrofuran to the amino-modified glucan to the basic catalyst is (3-5): (10-15):1: (0.3-0.5).

Preferably, the alkaline catalyst is at least one of sodium hydroxide, sodium carbonate, potassium hydroxide and potassium carbonate.

Preferably, the acellular nerve matrix is prepared in advance, and the preparation method refers to embodiment 1 of Chinese patent 201811545274.3; the hydroxyl-terminated poly (lactic acid-glycolic acid 75/25) copolymer is a hydroxyl-terminated poly (lactic acid-glycolic acid) copolymer OH-PLGA-OH75/25, has the weight-average molecular weight of 12 ten thousand, and is purchased from Dalian Meiren biotechnology Limited company; the weight average molecular weight of the amino modified glucan is 10 ten thousand, and the amino modified glucan is purchased from Xian Kai New Biotechnology Co.

Another object of the present invention is to provide a method for preparing the nerve repair scaffold, which comprises the following steps: uniformly mixing the raw materials to obtain a mixture, adding ultrapure water with the mass 5-10 times of that of the mixture, dispersing for 15-25 minutes by using ultrasonic, centrifuging for 10-30 minutes at the rotating speed of 2000-5000rmp, removing excessive water to obtain uniform paste slurry, adding the slurry into a mold, drying for 15-40 hours at the temperature of-80 ℃ by using a freeze dryer, spraying a photoinitiator solution with the mass fraction of 0.2-0.5% on the surface of the obtained material, irradiating for 35-45 minutes under ultraviolet light with the wavelength of 220-260nm, washing the product for 3-5 times by using water, finally placing the product in the freeze dryer, freeze-drying for 30-42 hours at the temperature of-80 ℃, and irradiating and sterilizing by using cobalt 60 to obtain the nerve repair stent.

Preferably, the photocatalyst solution is an ethanol solution of benzoin.

Adopt the produced beneficial effect of above-mentioned technical scheme to lie in:

(1) the nerve repair stent provided by the invention has the advantages of simple preparation method and process, convenience in operation, low preparation cost, high preparation efficiency and finished product qualification rate and strong clinical practicability.

(2) The nerve repair scaffold provided by the invention overcomes the defects that the nerve repair scaffold in the prior art has more or less limited sources, difficult material taking, danger of cross transmission of pathogenic microorganisms and difficult batch production; the mechanical property is poor, and the sufficient physical strength is lacked; the biological membrane has the advantages of large porosity, uniform pore diameter, good biocompatibility, good antibacterial and anti-inflammatory properties, excellent mechanical properties, biodegradability, auxiliary nerve repair function, high reliability, and high economic and social values.

(3) The nerve repair scaffold provided by the invention is non-toxic and harmless in selected materials, biodegradable, free of inflammation caused by degradation products, good in tissue biocompatibility, and due to the addition of the vinyl modified hydroxyl-terminated poly (lactic-glycolic acid 75/25) copolymer, reaction sites are provided by photocuring at a subsequent stage due to the introduction of vinyl, so that the mechanical properties of the nerve repair scaffold are improved; the pearl powder is introduced to play a role in enhancing the nerve repair stent on one hand, and has a better health care effect on the other hand, so that the pearl powder is beneficial to the health after being degraded in a human body; the addition of the amino modified glucan modified carboxylated fullerene and the amino modified glucan modified graphene oxide enhances the lubricity and the hydrophilicity of the wall of the stent tube on the one hand, and endows the stent with good conductivity on the other hand, and can form a micro-current path with nerve tissues or nerve cells, thereby being beneficial to the repair of damaged nerves; the acellular nerve matrix can endow the material with bionic characteristics, and all raw materials have synergistic effect, so that the obtained nerve repair scaffold has high water content, excellent comprehensive mechanical property and stability, biological activity and electric activity, and has the advantages of being beneficial to promoting the growth and proliferation of the Schwann cells and guiding the regeneration of axons.

Detailed Description

In order to make the technical solutions of the present invention better understood and make the above features, objects, and advantages of the present invention more comprehensible, the present invention is further described with reference to the following examples. The examples are intended to illustrate the invention only and are not intended to limit the scope of the invention.