A composite conductive hydrogel material with an artificial neural network structure and its preparation method

Abstract

The present invention discloses a composite conductive hydrogel material with an artificial neural network structure and a preparation method thereof. The method includes: 1) preparing sodium alginate fibers in a Ca<supgt;2+< / supgt; / Mg<supgt;2+< / supgt; coagulation bath, weaving them into a fiber mesh, and then impregnating the fiber mesh in an aniline / phytic acid solution to obtain a sodium alginate / polyaniline conductive fiber mesh; 2) performing surface modification on β-TCP using dopamine / Tris-HCl (pH = 8.5) and adsorbing osteogenic growth factors to obtain organic-inorganic hybrid nanoparticles; 3) formulating a pre-solution using Gelma, SilMA, and ChiMA, adding the prepared organic-inorganic hybrid β-TCP particles, and placing the sodium alginate / polyaniline conductive fiber mesh in the pre-solution for curing to obtain a composite conductive hydrogel material with an artificial neural network structure. The material has high biocompatibility, degradability, conductivity, nerve regeneration promotion property, and osteogenesis promotion property, and shows great application prospects in the field of skull repair.

Description

Technical Field

[0001] The present invention relates to the field of preparation of biomedical materials, and particularly to a composite conductive hydrogel material with an artificial neural network structure and a preparation method thereof. Background Art

[0002] Skull defects are caused in part by open craniocerebral trauma or missile penetrating wounds, and in part by surgical decompression, trephine destruction or resection of skull lesions caused by skull diseases. Currently, the commonly used clinical treatment methods are autologous bone transplantation or allogeneic bone transplantation and other techniques, but they are limited by problems such as rejection reactions or shortage of sources. In recent years, with the development of tissue engineering technology, biomedical hydrogel materials have shown great potential in the treatment of skull defects. However, traditional biomedical hydrogel materials have low bioactivity and single functions, and cannot meet the complex physiological environment requirements of skull defect sites.

[0003] As a highly vascularized and innervated organ, the internal blood vessels and neural network in the skull play a very important role in its regeneration process (such as nutrient exchange, metabolism, innervation, etc.). In recent years, there have been many studies and reports on the regulatory role and related mechanisms of vascularization on osteogenesis, but there are few reports on the impact of innervation on osteogenesis.

[0004] Conductive polymer hydrogels are three-dimensional water-containing polymer networks with conductive functions. With excellent electrical conductivity and high biocompatibility and other advantages, they have received great attention in the fields of nerve repair, spinal cord repair, etc. However, conductive polymers have poor processability and are insoluble and infusible, which greatly limits their application in this field. The human neural network is a complex network structure formed by a large number of neurons interconnected through synapses. Action potentials can occur and propagate sequentially along nerve fibers to form the conduction of nerve impulses, indicating that the neural network structure of the human body has innate advantages for the conduction of bioelectric signals.

[0005] Therefore, the present invention uses fibers as templates, in-situ introduces a conductive polymer layer on their surfaces to prepare conductive fiber materials, and realizes the three-dimensional simulation of the human neural network. Furthermore, it is nested in a hydrogel to form a composite conductive hydrogel material, and at the same time integrates functional components with osteogenic promoting effects to improve the therapeutic effect of skull defect repair. Summary of the Invention

[0006] The purpose of the present invention is to provide a composite conductive hydrogel material with an artificial neural network structure and a preparation method thereof in view of the deficiencies of the prior art and by combining the advantages of various materials and processes.

[0007] The present invention is realized by adopting the following technical solutions:

[0008] The composite conductive hydrogel material with an artificial neural network structure is constructed based on a sodium alginate / polyaniline conductive fiber network, Gelma (methacrylated gelatin), SilMA (methacrylated silk fibroin), and ChiMA (methacrylated chitosan) polymer gels, as well as organic-inorganic hybrid β-TCP nanoparticles adsorbed with growth factors. In this material, the sodium alginate / polyaniline conductive fiber network is laid flat in the gel matrix, and the organic-inorganic hybrid β-TCP nanoparticles adsorbed with growth factors are uniformly dispersed in the gel matrix. This composite conductive hydrogel material with an artificial neural network structure is prepared by a multi-step method. The specific preparation steps are as follows:

[0009] 1) Prepare a sodium alginate spinning solution and a Ca 2+ / Mg 2+ coagulation bath, and use a micro-injection pump for wet spinning to obtain sodium alginate fibers. After drying with a micro-airflow, twist treatment is carried out to obtain sodium alginate fiber bundles, and then a three-dimensional fiber network is woven according to a designed specific structure;

[0010] 2) Immerse the sodium alginate fiber network prepared in step 1) (without dialysis, retaining excess free Ca 2+ / Mg 2+ ) in an aniline / phytic acid solution, and add an initiator for in-situ polymerization for 2-4 h under stirring conditions. After complete dialysis and drying, a sodium alginate / polyaniline composite fiber network is obtained;

[0011] 3) Immerse β-TCP in a dopamine / Tris-HCl (pH = 8.5) solution. After dopamine self-polymerizes for a certain time, the nanoparticles are repeatedly washed by centrifugation, and then immersed in a solution containing osteogenic growth factors to load factors in the pores of the β-TCP / polydopamine nanoparticles to obtain organic-inorganic hybrid β-TCP particles; 4) Use Gelma, SilMA, and ChiMA as raw materials, dissolve them in a photoinitiator / PBS solution, and add a certain amount of the organic-inorganic hybrid β-TCP particles prepared in step 2). After uniform dispersion, a polymer pre-solution is obtained;

[0012] 5) Pour and spread a part (such as 3 / 5 volume) of the pre-solution in a mold, then lay the sodium alginate / polyaniline composite fiber network flat on the solution. After complete infiltration, continue to pour the remaining pre-solution. After leveling, a composite conductive hydrogel material with an artificial neural network structure is obtained by in-situ ultraviolet curing.

[0013] In the above technical solution, further, the viscosity of sodium alginate (10 g / L, 20 °C) in step 1) is 0.02 - 0.1 Pa·s, and the concentration of the sodium alginate aqueous solution is 3 - 6 wt%; the rate of the micro-injection pump is 1 - 2 ml / min, the diameter of the spinning orifice is 0.1 - 0.3 mm, and the fiber obtained after drying the sodium alginate fiber using a micro-airflow drying process (using a sterile nitrogen gas flow, a porous nozzle generates a uniform planar gas flow, and the gas flow rate of 1 - 5 m / s is used for drying to prevent fiber breakage caused by drying and other processes) is a flat fiber (dried on a winding device, the fiber volume shrinks during the drying process, and at the same time is restricted by the winding device, generating a tensile force on the fiber axis to promote the improvement of the fiber tensile strength, the fiber diameter is about 100 - 200 microns, and dialysis is not performed before fiber drying to ensure fiber strength). During the fiber twisting process, 4 - 8 fibers are used to form a fiber bundle each time, and the structure of the fiber web can be as Figure 1 shown.

[0014] Further, the coagulation bath formula in the above step 1) is: Ca 2+ / Mg 2+ The total concentration is 5 - 15 wt%, sodium sulfate is 2 - 5 wt%, glycerol is 2 - 5 wt%, and the rest is a mixed solvent of water and ethanol (where the volume ratio of ethanol to water can usually be 40:60, 50:50, 60:40). Among them, Ca 2+ comes from one or several of calcium chloride, calcium nitrate, etc., and Mg 2+ comes from one or several of magnesium chloride, magnesium nitrate, etc., and the molar ratio between the two is 50:50. Among them, the introduction of Ca 2+ / Mg 2+ can not only achieve ionic cross-linking of sodium alginate, but also serve for bone formation of the subsequent material; the introduction of glycerol and ethanol can promote wet spinning and prevent fiber breakage.

[0015] Further, the concentration of the aniline / phytic acid solution in the above step 2) is: aniline 0.005 - 0.02 g / ml, phytic acid 0.04 - 0.1 g / ml, Ca 2+ 0.05 - 0.15 g / ml, and the initiator is 0.002 - 0.01 g / ml. Among them, Ca 2+ comes from one or several of calcium chloride, calcium nitrate, etc., and the initiator is one of potassium persulfate, sodium persulfate, and ammonium persulfate; since sodium alginate is physically cross-linked using metal ions, the fiber dissolves under high phytic acid concentration conditions, and aniline needs to be protonated under acidic conditions to dissolve in water. Therefore, the dosage of aniline / phytic acid in the present invention is limited. In the above formula of the present invention, it not only ensures the smooth dissolution of aniline but also ensures that the sodium alginate fiber does not dissolve; at the same time, when the sodium alginate fiber web was woven in the early stage, dialysis was not performed (retaining Ca 2+ / Mg2+ and other solute components), as well as Ca 2+ The introduction of can further ensure that the sodium alginate fiber does not dissolve during the aniline polymerization process.

[0016] Furthermore, in the above step 3), the concentration of β-TCP added to the dopamine / Tris-HCl solution is 0.001 - 0.005 g / ml, the dopamine concentration is 2 - 6 mg / ml, and the reaction time is 6 - 48 hours; the centrifugation and washing rate is 10000 - 15000 revolutions per minute, the centrifugation time for each time is 10 - 15 minutes, and the number of centrifugations is 3 - 5 times;

[0017] Furthermore, the conditions for the loading factor of the mineralized β-TCP nanoparticles in the above step 3) are: adding nanoparticles with a concentration of 0.002 - 0.005 g / ml and a growth factor concentration of 5 - 20 μg / ml in a solution containing osteogenic growth factors. The osteogenic growth factors can be BMP-2, RGD peptides, etc., the impregnation time is 2 - 4 h, the temperature is 4 degrees, and the magnetic stirring condition is 200 - 400 r / min;

[0018] Furthermore, the grafting degrees of Gelma, SilMA, and ChiMA in the above step 4) can be 30 - 90%, the total concentration is 10 - 30 wt%, the mass ratio of Gelma, SilMA, and ChiMA is 1:1:1, and they are dissolved in a 60°C water bath; the concentration of the mineralized β-TCP nanoparticles adsorbed with factors is 0.05 - 0.2 wt%, and they are added and mixed evenly when the above polymer solution is dissolved and cooled to 40°C; the photoinitiator can be one or several of LAP, I2959, etc., with a concentration of 0.2 - 0.5 wt%, and the whole process is carried out in the dark.

[0019] Furthermore, the wavelength of the ultraviolet light curing light source in the above step 5) is 405 nm, and the light curing time is 30 seconds - 20 minutes.

[0020] Compared with the prior art, the present invention has the following advantages / innovations:

[0021] 1) The composite conductive hydrogel in this invention uses Gelma, SilMA, ChiMA, sodium alginate, aniline, phytic acid, β-TCP (β-tricalcium phosphate), dopamine, osteogenic growth factors, etc. as raw materials, and uses a combination of processes such as wet spinning, fiber twisting, fiber braiding, impregnation process, in-situ free radical polymerization, adsorption process, in-situ casting, and ultraviolet light curing to successfully prepare a composite conductive hydrogel material with high biocompatibility, degradability, conductivity, nerve regeneration promotion property, and osteogenesis promotion property.

[0022] 2) The raw materials used in the hydrogel material of this invention play different roles in this system, providing various functions for the hydrogel material: Gelma, SilMA, ChiMA, etc. are in-situ photocured to form a gel matrix. The three polymers provide good high biocompatibility and biodegradability for the matrix, and by forming a triple gel network structure, significantly enhance the mechanical strength of the hydrogel; The organic-inorganic hybrid β-TCP nanoparticles adsorbed with factors are uniformly dispersed in the matrix by virtue of the surface polydopamine coating, and the adsorbed osteogenic growth factors are slowly released to promote bone tissue regeneration. At the same time, β-TCP can rely on supplementing calcium and phosphate ions from body fluids to help form new bone during degradation; The sodium alginate / polyaniline conductive fiber network is laid flat in the matrix to simulate the neural network structure, achieving secondary enhancement of the mechanical strength of the hydrogel while also providing excellent electrical conductivity to promote nerve regeneration, and nerve regeneration synergizes with osteogenesis. And Ca 2+ and Mg 2+ are released during the degradation of the fiber and also have the function of promoting osteogenesis. The triple osteogenic design provides a new strategy for the regenerative repair of cranial defects.

[0023] 3) The conductive fiber network material in the preparation process of this composite hydrogel is wet-spun through a special coagulation bath, and then dried by a micro-airflow drying process in an undialyzed state. The obtained sodium alginate fibers are twisted and woven to obtain a fiber network with a specific structure; Further, in-situ radical polymerization is carried out in an aniline / phytic acid prepolymerization solution containing Ca 2+ to obtain a sodium alginate / polyaniline conductive fiber network material, which is reported for the first time in this invention.

[0024] 4) This conductive hydrogel material successfully realizes the bionic simulation of the neural network structure: A sodium alginate / polyaniline conductive fiber network with a three-dimensional network structure is innovatively introduced into the hydrogel matrix, and at the same time, mineralized β-TCP nanoparticle fillers loaded with factors are introduced into the prepolymerization solution. Secondary composite is carried out from the microscopic and macroscopic structures, enabling the sodium alginate / polyaniline conductive fiber network to simulate the neural network structure, and at the same time, the hydrogel material with nanoparticles around it simulates human tissues. Description of the Drawings

[0025] Figure 1 It is a schematic diagram of a partially woven structure of the fiber network (including but not limited to the woven structure in the schematic diagram);

[0026] Figure 2 They are photos of (a) sodium alginate fiber network and (b) sodium alginate / polyaniline conductive fiber network;

[0027] Figure 3SEM images of (a) sodium alginate fiber network and (b) sodium alginate / polyaniline conductive fiber network;

[0028] Figure 4 Photograph of the composite conductive hydrogel material with an artificial neural network structure;

[0029] Figure 5 Fluorescent live / dead cell staining photograph of the composite conductive hydrogel material with an artificial neural network structure after culturing with bone marrow mesenchymal stem cells (indicating excellent biocompatibility of the material). Detailed implementation mode

[0030] The technical solution of the present invention will be further described below in conjunction with the accompanying drawings and specific examples.

[0031] Example 1:

[0032] 1) Prepare a 4wt% sodium alginate spinning solution, centrifuge and degas it for later use. Prepare a coagulation bath (5wt% calcium chloride, 5wt% magnesium chloride, 2wt% sodium sulfate, 2wt% glycerol, and the rest is a mixed solvent of water and ethanol (where the volume ratio of ethanol to water is 50:50)), and use a micro-injection pump for wet spinning (injection rate 1ml / min, spinning orifice diameter 0.2mm, winding rate of the collection device 50 revolutions per minute) to obtain sodium alginate fibers. After drying with a micro-airflow (drying with a gas at 2m / s for 1 hour), twist 4 fibers as a unit to obtain a sodium alginate fiber bundle, and then weave it according to the designed specific structure to obtain a three-dimensional fiber network ( Figure 2 a); 2) Immerse the sodium alginate fiber network prepared in step 1) (without dialysis, retaining excess free Ca 2+ / Mg 2 + ) in an aniline / phytic acid solution (0.01g / ml aniline, 0.1g / ml phytic acid, 0.15g / ml calcium chloride), add an ammonium persulfate initiator (0.003g / ml) under stirring conditions for in-situ polymerization for 4h, dialyze completely, and dry at 37°C at low temperature to obtain a sodium alginate / polyaniline composite fiber network;

[0033] 3) Immerse 0.002g / ml β-TCP in a 2mg / ml dopamine / Tris-HCl (pH = 8.5) solution. After self-polymerization of dopamine for 6 hours, centrifuge at 10,000 revolutions per minute for 10 minutes, wash the nanoparticles repeatedly 3 times, and immerse it in a 5μg / ml BMP-2 solution to load factors in the pores of the β-TCP / polydopamine nanoparticles, and centrifuge at 10,000 revolutions per minute for 10 minutes to obtain organic-inorganic hybrid β-TCP particles;

[0034] 4) Using 5 wt% Gelma, 5 wt% SilMA, and 5 wt% ChiMA as raw materials, dissolve them in a 0.25 wt% LAP / PBS solution in a 60 °C water bath, and add 0.05 g / ml of organic-inorganic hybrid β-TCP particles at 40 °C. After uniform dispersion, a polymer pre-solution is obtained;

[0035] 5) Pour and spread 3 / 5 volume of the pre-solution into a mold, then lay the sodium alginate / polyaniline composite fiber mesh flat on the solution. After complete infiltration, continue to pour the remaining pre-solution. After leveling, in-situ ultraviolet light curing is carried out for 5 minutes to obtain a composite conductive hydrogel material with an artificial neural network structure;

[0036] 6) The conductivity of the hydrogel is 1.89 S / cm, and it degrades by 92.2% in 28 days. The fiber is a flat filament with a diameter of about 122.6 microns. The fluorescence staining results of live and dead cells after co-culturing the composite conductive hydrogel and bone marrow mesenchymal stem cells prove that the material has excellent biocompatibility.

[0037] Example 2:

[0038] 1) Prepare a 6 wt% sodium alginate spinning solution, centrifuge and defoam it for later use. Prepare a coagulation bath (5 wt% calcium chloride, 5 wt% magnesium chloride, 2 wt% sodium sulfate, 2 wt% glycerol, and the rest is a mixed solvent of water and ethanol (where the volume ratio of ethanol to water is 50:50)), and carry out wet spinning using a micro-injection pump (injection rate 1 ml / min, spinning nozzle diameter 0.2 mm, collection device winding rate 50 revolutions per minute) to obtain sodium alginate fibers. After drying with a micro-airflow (drying with a gas at 2 m / s for 1 hour), twist 4 fibers as a unit to obtain a sodium alginate fiber bundle, and then weave it according to the designed specific structure to obtain a three-dimensional fiber network ( Figure 2 a); 2) Immerse the sodium alginate fiber network prepared in step 1) (without dialysis, retaining excess free Ca 2+ / Mg 2 + ) in an aniline / phytic acid solution (0.02 g / ml aniline, 0.10 g / ml phytic acid, 0.05 g / ml calcium chloride), and add an ammonium persulfate initiator (0.003 g / ml) under stirring conditions for in-situ polymerization for 4 h. After complete dialysis and low-temperature drying at 37 °C, a sodium alginate / polyaniline composite fiber network is obtained;

[0039] 3) Immerse 0.002 g / ml β-TCP in 2 mg / ml dopamine / Tris-HCl (pH = 8.5) solution. After 6 hours of self-polymerization of dopamine, centrifuge at 10,000 revolutions per minute for 10 minutes, wash the nanoparticles repeatedly 3 times, and immerse them in 5 μg / ml BMP-2 solution to load factors in the pores of β-TCP / polydopamine nanoparticles. Centrifuge at 10,000 revolutions per minute for 10 minutes to obtain organic-inorganic hybrid β-TCP particles;

[0040] 4) Use 5 wt% Gelma, 5 wt% SilMA, and 5 wt% ChiMA as raw materials, dissolve them in 0.25 wt% LAP / PBS solution in a 60°C water bath, and add 0.05 g / ml organic-inorganic hybrid β-TCP particles at 40°C. After uniform dispersion, obtain a polymer pre-solution;

[0041] 5) Pour 3 / 5 volume of the pre-solution onto a mold, then lay the sodium alginate / polyaniline composite fiber mesh on top of the solution. After complete infiltration, continue to pour the remaining pre-solution. After leveling, cure in situ with ultraviolet light for 5 minutes to obtain a composite conductive hydrogel material with an artificial neural network structure;

[0042] 6) Compared with Example 1, the concentrations of aniline, phytic acid, and calcium chloride were increased. The conductivity of the hydrogel was 2.19 S / cm, and 87.8% was degraded in 28 days. The fibers were flat filaments with a diameter of about 119.7 microns. The results of live-dead cell fluorescence staining after co-culturing the composite conductive hydrogel and bone marrow mesenchymal stem cells proved excellent biocompatibility of the material.

[0043] Example 3:

[0044] 1) Prepare a 4 wt% sodium alginate spinning solution, centrifuge to remove bubbles for later use. Prepare a coagulation bath (5 wt% calcium chloride, 5 wt% magnesium chloride, 2 wt% sodium sulfate, 2 wt% glycerol, and the rest is a mixed solvent of water and ethanol (where the volume ratio of ethanol to water is 50:50)), and use a micro-injection pump for wet spinning (injection rate 1 ml / min, spinning orifice diameter 0.2 mm, winding rate of the collection device 50 revolutions per minute) to obtain sodium alginate fibers. After drying with a micro-airflow (drying with a gas at 2 m / s for 1 hour), twist 4 fibers as a unit to obtain a sodium alginate fiber bundle, and then weave according to the designed specific structure to obtain a three-dimensional fiber network ( Figure 2 a); 2) The sodium alginate fiber network prepared in step 1) (without dialysis, retaining excess free Ca 2+ / Mg 2 +) Immerse in aniline / phytic acid solution (0.01 g / ml aniline, 0.1 g / ml phytic acid, 0.15 g / ml calcium chloride), add ammonium persulfate initiator (0.003 g / ml) under stirring conditions for in-situ polymerization for 4 h. After complete dialysis and low-temperature drying at 37 °C, a sodium alginate / polyaniline composite fiber network is obtained;

[0045] 3) Immerse 0.002 g / ml β-TCP in 2 mg / ml dopamine / Tris-HCl (pH = 8.5) solution. After dopamine self-polymerization for 6 hours, centrifuge at 10,000 revolutions per minute for 10 minutes, wash the nanoparticles repeatedly 3 times, and immerse them in 5 μg / ml BMP-2 solution to load factors in the pores of β-TCP / polydopamine nanoparticles. Centrifuge at 10,000 revolutions per minute for 10 minutes to obtain organic-inorganic hybrid β-TCP particles;

[0046] 4) Use 10 wt% Gelma, 10 wt% SilMA, and 10 wt% ChiMA as raw materials, dissolve them in 0.50 wt% LAP / PBS solution in a 60 °C water bath, and add 0.05 g / ml organic-inorganic hybrid β-TCP particles at 40 °C. After uniform dispersion, a polymer pre-solution is obtained;

[0047] 5) Pour 3 / 5 volume of the pre-solution onto a mold, then lay the sodium alginate / polyaniline composite fiber network flat on the solution. After complete infiltration, continue to pour the remaining pre-solution. After leveling, cure in-situ with ultraviolet light for 5 minutes to obtain a composite conductive hydrogel material with an artificial neural network structure;

[0048] 6) Compared with Example 1, the concentrations of Gelma, SilMA, and ChiMA are increased. The conductivity of the hydrogel is 1.54 S / cm, and it degrades 84.3% in 28 days. The fibers are flat filaments with a diameter of about 122.6 microns. The results of live-dead cell fluorescence staining after co-culturing the composite conductive hydrogel and bone marrow mesenchymal stem cells prove that the material has excellent biocompatibility.

[0049] Example 4:

[0050] 1) Prepare a 6 wt% sodium alginate spinning solution, centrifuge to remove bubbles and set aside. Prepare a coagulation bath (5 wt% calcium chloride, 5 wt% magnesium chloride, 2 wt% sodium sulfate, 2 wt% glycerol, and the rest is a mixed solvent of water and ethanol (where the volume ratio of ethanol to water is 50:50)), and use a micro-injection pump for wet spinning (injection rate 1 ml / min, spinning nozzle diameter 0.4 mm, winding rate of the collection device 50 revolutions per minute) to obtain sodium alginate fibers. After drying with a micro-airflow (drying with a gas at 2 m / s for 1 hour), twist 4 fibers as a unit to obtain a sodium alginate fiber bundle, and then weave according to the designed specific structure to obtain a three-dimensional fiber network (Figure 2 a); 2) Immerse the alginate fiber mesh prepared in step 1) (without dialysis, retaining the excess free Ca 2+ / Mg 2 + ) in an aniline / phytic acid solution (0.01 g / ml aniline, 0.1 g / ml phytic acid, 0.15 g / ml calcium chloride), add ammonium persulfate initiator (0.003 g / ml) under stirring conditions for in-situ polymerization for 4 h, and obtain an alginate / polyaniline composite fiber mesh after complete dialysis and low-temperature drying at 37 °C;

[0051] 3) Immerse 0.002 g / ml β-TCP in a 2 mg / ml dopamine / Tris-HCl (pH = 8.5) solution. After 6 hours of self-polymerization of dopamine, centrifuge at 10,000 revolutions per minute for 10 minutes, wash the nanoparticles 3 times repeatedly, and immerse them in a 5 μg / ml BMP-2 solution to load factors in the pores of the β-TCP / polydopamine nanoparticles, and obtain organic-inorganic hybrid β-TCP particles by centrifuging at 10,000 revolutions per minute for 10 minutes;

[0052] 4) Use 5 wt% Gelma, 5 wt% SilMA, and 5 wt% ChiMA as raw materials, dissolve them in a 0.25 wt% LAP / PBS solution in a 60 °C water bath, and add 0.05 g / ml organic-inorganic hybrid β-TCP particles at 40 °C. After dispersing evenly, obtain a polymer pre-solution;

[0053] 5) Pour 3 / 5 volume of the pre-solution into a mold and spread it out, then lay the alginate / polyaniline composite fiber mesh flat on the solution. After complete infiltration, continue to pour the remaining pre-solution, and obtain a composite conductive hydrogel material with an artificial neural network structure after leveling and in-situ ultraviolet light curing for 5 minutes;

[0054] 6) Compared with Example 1, increasing the spinning solution concentration and the spinneret aperture, the conductivity of the hydrogel is 1.64 S / cm, and it degrades 89.4% in 28 days. The fiber is a flat filament with a diameter of about 243.5 microns. The results of live-dead cell fluorescence staining after co-culturing the composite conductive hydrogel and bone marrow mesenchymal stem cells prove that the material has excellent biocompatibility.

Claims

1. A composite conductive hydrogel material with an artificial neural network structure, characterized in that: The material is constructed by combining a sodium alginate / polyaniline conductive fiber network, Gelma, SilMA, and ChiMA polymer gel matrices, and organic-inorganic hybrid β-TCP nanoparticles adsorbed with growth factors. In this material, the sodium alginate / polyaniline conductive fiber network is laid flat in the gel matrix, and the organic-inorganic hybrid β-TCP nanoparticles adsorbed with growth factors are uniformly dispersed in the gel matrix; The preparation steps of this composite conductive hydrogel material are as follows: 1) Preparation of sodium alginate spinning solution and Ca 2+ / Mg 2+ A coagulation bath is used, and a micro-syringe pump is used for wet spinning to obtain sodium alginate fibers, and after micro-airflow drying, the fibers are twisted to obtain sodium alginate fiber bundles, and then woven according to the designed structure to obtain a three-dimensional fiber web; 2) Without dialysis, directly immerse the sodium alginate fiber network prepared in step 1) in an aniline / phytic acid solution, add an initiator for in-situ polymerization for 2 - 4 h under stirring conditions, and after complete dialysis and drying, obtain a sodium alginate / polyaniline composite fiber network; 3) Immerse β-TCP in a dopamine / Tris-HCl solution with a solution pH of 8.

5. After dopamine self-polymerizes for a certain time, repeatedly wash the nanoparticles by centrifugation, and immerse them in a solution containing an osteogenic growth factor to load the factor in the pores of the β-TCP / polydopamine nanoparticles, obtaining organic-inorganic hybrid β-TCP particles; 4) Use Gelma, SilMA, and ChiMA as raw materials, dissolve them in a photoinitiator / PBS solution, and add the organic-inorganic hybrid β-TCP particles prepared in step 2). After uniform dispersion, obtain a polymer pre-solution; 5) Pour and spread part of the pre-solution into a mold, then lay the sodium alginate / polyaniline composite fiber network flat on the solution. After complete infiltration, continue to pour the remaining pre-solution. After leveling, obtain a composite conductive hydrogel material with an artificial neural network structure through in-situ ultraviolet curing.

2. The composite conductive hydrogel material with an artificial neural network structure according to claim 1, characterized in that: In step 1), the viscosity of sodium alginate with a concentration of 10 g / L at 20 °C is 0.02 - 0.1 Pa·s, and the concentration of the sodium alginate aqueous solution is 3 - 6 wt%; the rate of the micro-injection pump is 1 - 2 ml / min, the diameter of the spinning nozzle is 0.1 - 0.3 mm, and the micro-airflow drying process uses a sterile nitrogen gas flow. The porous nozzle generates a uniform planar airflow, and the gas flow rate for drying is 1 - 5 m / s.

3. The preparation method of the composite conductive hydrogel material with an artificial neural network structure according to claim 1, wherein: The coagulation bath formulation in Step 1) is: Ca 2+ / Mg 2+ with a concentration of 5-15 wt%, sodium sulfate 2-5 wt%, glycerol 2-5 wt%, and the balance being a mixed solvent of water and ethanol; wherein the molar ratio between Ca 2+ and Mg 2+ is 50:

50.

4. The composite conductive hydrogel material with an artificial neural network structure according to claim 1, characterized in that: The concentration of the aniline / phytic acid solution described in step 2) is as follows: aniline 0.005 - 0.02 g / ml, phytic acid 0.04 - 0.1 g / ml, Ca 2+ 0.05 - 0.15 g / ml, initiator 0.002 - 0.01 g / ml; where Ca 2+ is one or more of calcium chloride and calcium nitrate, and the initiator is one of potassium persulfate, sodium persulfate, and ammonium persulfate.

5. The composite conductive hydrogel material with an artificial neural network structure according to claim 1, characterized in that: In the dopamine / Tris-HCl solution in step 3), the concentration of β-TCP added is 0.001 - 0.005 g / ml, the concentration of dopamine is 2 - 6 mg / ml, and the reaction time is 6 - 48 hours; the rate of centrifugal cleaning is 10000 - 15000 revolutions per minute, the centrifugation time for each time is 10 - 15 minutes, and the number of centrifugations is 3 - 5 times.

6. The composite conductive hydrogel material with an artificial neural network structure according to claim 1, characterized in that: In step 3), immerse in a solution containing an osteogenic growth factor, where the concentration of nanoparticles is 0.002 - 0.005 g / ml, the concentration of growth factor is 5 - 20 μg / ml, the immersion time is 2 - 4 h, the temperature is 4 °C, and the magnetic stirring condition is 200 - 400 r / min.

7. The composite conductive hydrogel material with an artificial neural network structure according to claim 1, characterized in that: The grafting degrees of Gelma, SilMA, and ChiMA in step 4) are 30-90%, the total concentration is 10-30 wt%, the mass ratio of Gelma, SilMA, and ChiMA is 1:1:1, and they are dissolved in a 60°C water bath; the concentration of organic-inorganic hybrid β-TCP particles is 0.05-0.2 wt%, and it is added and mixed evenly when the above polymer solution is dissolved and cooled to 40°C; the concentration of the photoinitiator is 0.2-0.5 wt%, and the operation is carried out in the dark throughout the process.

8. The composite conductive hydrogel material with an artificial neural network structure according to claim 1, characterized in that: In step 5), the wavelength of the ultraviolet curing light source is 405 nm, and the light curing time is 30 seconds to 20 minutes.

9. The application of the composite conductive hydrogel material with an artificial neural network structure as claimed in claim 1, wherein: In the composite conductive hydrogel material, the alginate / polyaniline fiber network simulates the neural network structure as the conduction network of bioelectricity in the body, and the rest of the gel matrix simulates the tissue microenvironment, promoting nerve repair on the one hand and osteogenesis on the other hand. The composite conductive hydrogel material is used as a bone repair material or a bone tissue engineering material.

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