Medical implant, preparation method thereof and artificial knee joint

Abstract

The invention provides a medical implant, a preparation method thereof and an artificial knee joint. The medical implant comprises a macromolecular porous stent and a hydrogel composite material at least filled in pores of the macromolecular porous stent, and the material of the macromolecular porous stent comprises a degradable macromolecular material and carbon nanotubes distributed in the degradable macromolecular material. The hydrogel composite material comprises a hydrogel material matrix and seed cells distributed in the hydrogel material matrix. According to the invention, the degradable high polymer material and the hydrogel material are combined, the carbon nanotubes are introduced into the degradable high polymer material, and meanwhile, seed cells are arranged in a hydrogel material matrix, so that the implantable stent material which has proper degradation performance and good mechanical properties and is renewable is provided.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of medical devices, in particular to a medical implant, a preparation method thereof and an artificial knee joint. BACKGROUND

[0002] Meniscus, as a semilunar fibrocartilage tissue between femoral condyle and tibial plateau, helps to bear and transmit external force on the joint, and has the functions of stabilizing the joint and shock absorption. The incidence of meniscus injury is high, and once the meniscus injury is large, surgical resection is needed, which can cause early joint cartilage damage and eventually lead to early osteoarthritis. Artificial meniscus replacement is an effective treatment method.

[0003] At present, there are three types of artificial synthetic meniscus approved for marketing worldwide. One is artificial collagen meniscus implant (CMI), which has good biocompatibility, but the collagen degrades too fast, causing the meniscus scaffold to collapse, ultimately leading to failure of meniscus repair. The second is polyurethane meniscus (Actifit), which has good degradation performance, but its mechanical properties do not match, resulting in a high early failure rate after meniscus scaffold implantation. The third is polycarbonate reinforced polyurethane meniscus scaffold (NUSurface), which has good mechanical bionic performance, but its material does not degrade basically, and has no porous structure for cell ingrowth. Therefore, it is very urgent to develop a medical implant suitable for artificial meniscus, which has appropriate degradation performance, good mechanical properties and is regenerative. SUMMARY

[0004] Therefore, it is necessary to provide a medical implant with appropriate degradation performance, good mechanical properties and regenerative ability, a preparation method thereof and an artificial knee joint.

[0005] In one aspect of the present application, a medical implant is provided, which comprises a high molecular porous scaffold and a hydrogel composite material filled in the pores of the high molecular porous scaffold, the material of the high molecular porous scaffold comprises a degradable high molecular material and carbon nanotubes distributed in the degradable high molecular material, and the hydrogel composite material comprises a hydrogel material matrix and seed cells distributed in the hydrogel material matrix.

[0006] The application combines degradable polymer materials and hydrogel materials, and introduces carbon nanotubes (CNT) into the degradable polymer materials, thereby improving the mechanical properties of the degradable polymer materials, adjusting the degradation performance of the degradable polymer materials, and improving the cell compatibility of the degradable polymer materials. Meanwhile, by arranging seed cells in the hydrogel material matrix, the survival conditions of the cells are ensured, so that the medical implant is beneficial to the repair and regeneration of meniscus and other tissues. Therefore, the medical implant is an implant material with appropriate degradation performance, good mechanical properties and regeneration.

[0007] In the medical implant, the hydrogel material matrix and the seed cells distributed in the hydrogel material matrix play a role in promoting tissue repair and regeneration, and the degradable polymer serves as a mechanical support for the meniscus scaffold and realizes the creeping replacement of the medical implant for tissue repair through adjustable degradation performance.

[0008] The medical implant can be used not only for artificial meniscus but also for other medical implants, realizes meniscus repair treatment, and is applied to other regeneration and repair fields. As an example, the medical implant is an artificial meniscus, i.e., a meniscus implant.

[0009] In some embodiments, the polymer porous scaffold includes a plurality of ribs connected to each other to form a three-dimensional network structure.

[0010] In some embodiments, the ribs have a concave-convex surface structure.

[0011] In some embodiments, the medical implant satisfies at least one of the following characteristics:

[0012] (1) The degradable polymer material includes at least one of polycaprolactone, polyurethane, polylactic acid, poly(lactic-co-glycolic acid), poly(lactic-co-caprolactone), and polyglycolic acid;

[0013] (2) The preparation raw material of the hydrogel material matrix includes one or more of methacrylated gelatin, collagen, chitosan, hyaluronic acid, and sodium alginate;

[0014] (3) The polymer porous scaffold is formed by 3D printing;

[0015] (4) The filling volume ratio of the hydrogel composite in the medical implant is 44% to 55%;

[0016] (5) The mass ratio of the carbon nanotubes to the degradable polymer material is (0.2 to 2): 100;

[0017] (6) The porosity of the polymer porous scaffold is 44% to 55%.

[0018] In some embodiments, the medical implant satisfies at least one of the following features:

[0019] (1) the degradable polymer material comprises polycaprolactone, and the molecular weight of the polycaprolactone is 10,000-10,000,000;

[0020] (2) the 3D printing comprises a fused deposition modeling technique.

[0021] In some embodiments, the medical implant satisfies at least one of the following features:

[0022] (1) the seed cells comprise at least one of embryonic stem cells, umbilical cord mesenchymal stem cells, bone marrow mesenchymal stem cells, and chondrocytes;

[0023] (2) the medical implant is an artificial meniscus.

[0024] Another aspect of the present application provides a preparation method of the medical implant as described above, comprising the following steps:

[0025] mixing the dispersion liquid of the carbon nanotubes with the degradable polymer material, and then drying to prepare a polymer composite material;

[0026] using the polymer composite material as a raw material to prepare a polymer porous scaffold;

[0027] applying a cell suspension for forming the hydrogel composite material to the polymer porous scaffold, and then performing ultraviolet curing crosslinking to obtain the medical implant; the cell suspension comprises hydrogel preparation raw materials, seed cells, and a photoinitiator.

[0028] In some embodiments, the preparation method satisfies at least one of the following features:

[0029] (1) before the cell suspension is applied, the following step is further included: immersing the polymer porous scaffold in an alkaline solution to perform surface etching to form a concave-convex surface structure;

[0030] (2) using the polymer composite material as a raw material to prepare the polymer porous scaffold through 3D printing;

[0031] (3) in the step of preparing the polycaprolactone composite material, the mass ratio of the carbon nanotubes in the carbon nanotube dispersion liquid to the polycaprolactone is (0.2-2):100.

[0032] In some embodiments, the preparation method satisfies at least one of the following features:

[0033] (1) the 3D printing is a fused deposition modeling technology; the printing condition of the 3D printing includes: an extrusion temperature of 60-100℃, an extrusion speed of 0.01-0.3 mm / s, a printing speed of 1-10 mm / s, a platform temperature of 25-50℃, an inner diameter of a printing nozzle of 0.1-0.5 mm, and a diameter wire spacing of 0.3-1 mm, wherein the inner diameter of the printing nozzle is less than the diameter wire spacing;

[0034] (2) the ultraviolet light intensity for the ultraviolet curing crosslinking is 10-30 mW / cm 2 ~30mW / cm 2 , and the processing time is 40-60 s.

[0035] In some embodiments, the preparation method satisfies at least one of the following features:

[0036] (1) in the cell suspension, the mass-volume ratio of the hydrogel preparation monomer to solvent water is (5-12) g / 100 mL, the concentration of the seed cells is (1-6)×10 6 cells / mL, and the mass-volume ratio of the photoinitiator to solvent water is (0.1-1) g / 100 mL;

[0037] (2) the degradable high molecular material includes polycaprolactone, and the molecular weight of the polycaprolactone is 10-1,000,000;

[0038] (3) the hydrogel preparation raw material includes one or more of methyl methacrylate gelatin, collagen, chitosan, hyaluronic acid, and sodium alginate;

[0039] (4) the photoinitiator includes a phenyl (2,4,6-trimethylbenzoyl) lithium phosphate salt;

[0040] (5) the application amount of the cell suspension is determined according to the infiltration of all pores of the high molecular porous scaffold or the upper surface of the high molecular porous scaffold.

[0041] In another aspect of the present application, an artificial knee joint is provided, which includes any of the above medical implants, and the medical implant serves as an artificial meniscus of the artificial knee joint. BRIEF DESCRIPTION OF DRAWINGS

[0042] Figure 1 A 3D model of a bionic lateral meniscus of a rabbit;

[0043] Figure 2 A physical diagram of a meniscus high molecular porous scaffold prepared by the embodiment of the present application;

[0044] Figure 3Figure 1.1 is a Fourier transform infrared spectrogram of pure PCL material in Step 1.1 of the present application;

[0045] Figure 4 Figure 1.2 is a Fourier transform infrared spectrogram of 0.5CNT / PCL prepared in Step 1.1 of the present application;

[0046] Figure 5 Figure 1.3 is a Fourier transform infrared spectrogram of 1CNT / PCL prepared in Step 1.1 of the present application;

[0047] Figure 6 Figure 1.4 is a Fourier transform infrared spectrogram of 2CNT / PCL prepared in Step 1.1 of the present application;

[0048] Figure 7 Figure 1.5 is a result graph of degradation performance of different carbon nanotube / poly caprolactone composite materials of the present application;

[0049] Figure 8 Figure 1.6 is a result graph of MC3T3-E1 cells after being cultured in different carbon nanotube / poly caprolactone composite material leaching liquor for 1 day in the example of the present application;

[0050] Figure 9 Figure 1.7 is a result graph of MC3T3-E1 cells after being cultured in different carbon nanotube / poly caprolactone composite material leaching liquor for 3 days in the example of the present application;

[0051] Figure 10 Figure 1.8 is a result graph of the stiffness of 5% and 10% (w / v) GelMA solution changing with the increase of UV irradiation time;

[0052] Figure 11 Figure 1.9 is a result graph of the viscosity of 10% (w / v) GelMA solution and 10% (w / v) GelMA+MC3T3-E1 cells solution changing with the change of temperature;

[0053] Figure 12 Figure 1.10 is a result graph of the stiffness of 10% (w / v) GelMA+MC3T3-E1 cells solution changing with the increase of different intensity UV irradiation and different UV irradiation time;

[0054] Figure 13 Figure 1.11 is a light microscope result graph of MC3T3-E1 cells after being cultured on the surface of GelMA hydrogel and the surface of a culture plate for 2 days;

[0055] Figure 14 Figure 1.12 is a staining result graph of MC3T3-E1 cells after being cultured in three different concentrations (5% (w / v) (left), 6.6% (w / v) (middle) and 10% (w / v) (right)) of GelMA hydrogel for 3 days;

[0056] Figure 15 Fig. 2 is a graph showing the growth of umbilical cord mesenchymal stem cells in the GelMA / CNT / PCL scaffolds prepared in Examples 1-2 after 7 days of culture;

[0057] Figure 16 Fig. 3 is a graph showing the growth of umbilical cord mesenchymal stem cells in the GelMA / CNT / PCL meniscus scaffolds prepared in Examples 2, 4 and Comparative Example 2 after 7 days of culture. DETAILED DESCRIPTION

[0058] For the purpose of promoting an understanding of the application, the application will now be described in greater detail with reference to the relevant drawings. The preferred embodiments of the application are illustrated in the drawings. However, the application can be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. It should be understood that these embodiments have been provided merely for the purposes of illustration.

[0059] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description of the application herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0060] In the description of the application, the meaning of "a plurality of" is two or more, unless otherwise explicitly specified.

[0061] An embodiment of the application provides a medical implant, comprising a polymer porous scaffold and a hydrogel composite material filled in at least the pores of the polymer porous scaffold. The material of the polymer porous scaffold comprises a degradable polymer material and carbon nanotubes distributed in the degradable polymer material, and the hydrogel composite material comprises a hydrogel material matrix and seed cells distributed in the hydrogel material matrix.

[0062] Hydrogels are widely used as cartilage and meniscus tissue engineering scaffold materials. Due to its special network structure, hydrogels provide sufficient growth space for cells, and its high water content provides suitable living conditions for cells. However, the high porosity of hydrogels often leads to poor mechanical properties, and medical implants such as meniscus require good mechanical properties for stress support and transmission.

[0063] The application combines degradable polymer materials and hydrogel materials, and introduces carbon nanotubes (CNT) into the degradable polymer materials, thereby improving the mechanical properties of the degradable polymer materials, adjusting the degradation performance of the degradable polymer materials, and improving the cell compatibility of the degradable polymer materials. Meanwhile, by arranging seed cells in the hydrogel material matrix, the survival conditions of the cells are ensured, so that the medical implant is beneficial to the repair and regeneration of meniscus and other tissues. Therefore, the medical implant is an implant material with appropriate degradation performance, good mechanical properties and regeneration.

[0064] In the medical implant, the hydrogel material matrix and the seed cells distributed in the hydrogel material matrix play a role in promoting tissue repair and regeneration. The degradable polymer serves as a mechanical support for the meniscus scaffold on one hand, and realizes the creeping replacement of the medical implant for tissue repair on the other hand through adjustable degradation performance.

[0065] The medical implant can be used not only for artificial meniscus to realize meniscus repair treatment, but also for other medical implants and applied to other regeneration and repair fields. As an example, the medical implant is an artificial meniscus, i.e., a meniscus implant.

[0066] It can be understood that the selection of the seed cells includes but is not limited to at least one of embryonic stem cells, umbilical cord mesenchymal stem cells, bone marrow mesenchymal stem cells and chondrocytes, which can differentiate into chondrocytes, and these cells are widely used in meniscus repair tissue engineering. These can be sourced from commercial purchases.

[0067] Among them, the selection of seed cells is based on different animal models or purposes, such as mouse, rabbit, pig, human embryonic stem cells, umbilical cord mesenchymal stem cells, bone marrow mesenchymal stem cells and chondrocytes.

[0068] Alternatively, the seed cells include umbilical cord mesenchymal stem cells.

[0069] As an example, human umbilical cord mesenchymal stem cells are selected, and the extraction and culture scheme is as follows: human umbilical cord tissue is taken from a woman who gave birth on the same day, and is stored in α-MEM at 4 ℃ for 12-18 hours. Then the umbilical cord tissue is soaked in 70% alcohol for 15-60 seconds, and then the umbilical cord is rinsed with PBS three times. After removing the three blood vessels in the umbilical cord, the Wharton's jelly in the umbilical cord is taken, cut into small pieces with a width of 2-6 mm. The cut Wharton's jelly pieces are rinsed with PBS three times, and then the tissue pieces are placed in a culture dish and cultured in αMEM medium containing 10% FBS, 2mM L-glutamine and 100U / ml penicillin / streptomycin. The medium is changed twice a week. When the cell confluence in the dish is about 80-90%, the cells are digested with 0.25% trypsin-EDTA for 5 minutes and passaged. When the cells are passed to the fourth generation, they are digested with trypsin for standby use.

[0070] In some embodiments, the mass ratio of the carbon nanotubes to the degradable polymer material is (0.2-2):100.

[0071] As an example, the mass ratio can be 0.2:100, 0.3:100, 0.4:100, 0.5:100, 0.6:100, 0.8:100, 1:100, 1.2:100, 1.5:100, 1.6:100, 1.8:100, 2:100. In some embodiments, the mass ratio can also be a range formed by any two of the above point values as end values, for example, it can be (0.5-2):100 or (0.8-1.5):100, and the like below. Controlling the mass ratio of the carbon nanotubes to the degradable polymer material within this further range not only makes the polymer scaffold have better mechanical properties, but also has better cell compatibility.

[0072] In some embodiments, the degradable polymer material includes at least one of polycaprolactone, polyurethane, polylactic acid, polylactic acid-glycolic acid copolymer, polylactic acid-polycaprolactone copolymer, polyamino acid, and polyglycolic acid.

[0073] As an example, the degradable polymer material includes polycaprolactone, and the molecular weight of the polycaprolactone is 10,000-10 million.

[0074] In some embodiments, the hydrogel material matrix includes one or more of methacrylated gelatin, collagen, chitosan, hyaluronic acid, and sodium alginate.

[0075] As an example, the raw material for preparing the hydrogel material matrix includes methacrylated gelatin.

[0076] In some embodiments, the method for preparing the methacrylated gelatin includes steps S11-S12.

[0077] S11, dissolving gelatin in an aqueous solution of sodium bicarbonate and sodium carbonate to obtain a gelatin solution. A specific example is as follows: 10 g of gelatin is completely dissolved in 100 mL of a Carbonate-bicarbonate solution (12.5 mM sodium bicarbonate + 87.5 mM sodium carbonate) at 50-55 °C to obtain a gelatin solution.

[0078] S12, adding methacrylic anhydride (MA) to the gelatin solution according to a ratio of 0.05-0.3 mL: 1 g of gelatin, and then reacting at 50-55 °C under stirring at 400-600 rpm for 1-3 h; adjusting the pH of the solution to 7.4 with 1 M HCl to terminate the reaction; collecting the supernatant by centrifugation at 4000 rpm for 5-10 min at room temperature, and then dialyzing the supernatant at 40 °C using a 14 kDa dialysis membrane for 72 h, and finally freeze-drying to obtain GelMA (methacrylated gelatin).

[0079] The grafting degree of the methacrylated gelatin prepared by the preparation process is relatively high.

[0080] Another embodiment of the present application provides a preparation method of the medical implant described above, comprising the following steps S21-S23. It should be noted that some features have been described in detail above and will not be expanded here.

[0081] S21, mixing a dispersion liquid of carbon nanotubes with a degradable high polymer material and drying to prepare a high polymer composite material.

[0082] In some embodiments, the mass ratio of the carbon nanotubes to the degradable high polymer material in step S21 is (0.2-2): 100.

[0083] In some embodiments, the solvent of the dispersion liquid of the carbon nanotubes includes volatile organic solvents such as dichloromethane.

[0084] In some embodiments, the mixing in step S21 is performed by stirring, for example, shaking at a speed of 100 rpm (revolutions per minute) to 300 rpm for 3-8 h.

[0085] In some embodiments, the drying in step S21 can be performed by at least one of natural air drying and vacuum drying, for example, natural air drying followed by vacuum oven drying at room temperature for 1-4 h.

[0086] S22, using the high polymer composite material as a raw material to prepare a high polymer porous scaffold.

[0087] In some embodiments, the polymer porous scaffold is formed by 3D printing of the polymer composite material. It is understood that other manufacturing processes can also be used to form the polymer porous scaffold. Further, the 3D printing includes, but is not limited to, fused deposition modeling.

[0088] In an example, the polymer porous scaffold is formed by fused deposition modeling of the polymer composite material. Fused deposition modeling is a process of melting low-melting-point filament material into liquid through an extrusion head of a heater, extruding the melted thermoplastic filament through a nozzle, accurately moving the extrusion head along the profile of each cross-section of the part, depositing and solidifying the semi-liquid thermoplastic material into precise layers of the actual part, covering the already built part, and quickly solidifying, and after each layer is formed, the worktable is lowered by one layer height, and the nozzle sprays the next layer of cross-section, and so on, until the last layer, and thus the layers are stacked from bottom to top to form a solid model or part. The polymer porous scaffold formed in this way includes a plurality of ribs connected to each other to form a three-dimensional network structure.

[0089] It is understood that the ribs in the three-dimensional network structure are formed by the thermoplastic filament material, and the pores in the polymer porous scaffold are the network pores in the three-dimensional network structure formed between the plurality of ribs.

[0090] In some embodiments, the porosity of the polymer porous scaffold is 44% to 55%. As an example, the porosity of the polymer porous scaffold can be 44%, 45%, 46%, 48%, 50%, 52%, 54%, 55%. It is understood that the porosity of the polymer porous scaffold refers to the porosity before the hydrogel composite material is filled, and the porosity of the polymer porous scaffold provides space for the hydrogel composite material to be filled.

[0091] Further, the inner diameter of the printing nozzle in the printing condition of the fused deposition modeling is less than the filament diameter, so that the obtained scaffold has a porous structure.

[0092] Further, the printing condition of the fused deposition modeling includes: the extrusion temperature is 60°C to 100°C, the extrusion speed is 0.01 mm / s to 0.3 mm / s, the printing speed is 1 mm / s to 10 mm / s, the platform temperature is 25°C to 50°C, the inner diameter of the printing nozzle (i.e. the filament diameter) is 0.1 mm to 0.5 mm, the filament spacing (i.e. the pore diameter) is 0.3 mm to 1 mm, and the inner diameter of the printing nozzle is less than the filament spacing.

[0093] In some embodiments, a printing model design step is also required before 3D printing, for example, the meniscus model is designed according to the original meniscus of the organism, and the medial meniscus is shaped like an "O", and the lateral meniscus is shaped like a "C".

[0094] S23, applying the cell suspension for forming the hydrogel composite into the high-molecular porous scaffold, and then performing ultraviolet curing crosslinking to obtain the medical implant; the cell suspension comprises hydrogel preparation monomers, seed cells, and a photoinitiator.

[0095] In some embodiments, the mass-volume ratio of the hydrogel preparation monomers to solvent water in the cell suspension is (5-12) g / 100 mL; for example, it can be 5 g / 100 mL, 6 g / 100 mL, 8 g / 100 mL, 10 g / 100 mL, 11 g / 100 mL, 12 g / 100 mL, and further, it can be (8-10) g / 100 mL.

[0096] In some embodiments, the concentration of the seed cells in the cell suspension is (1-6) ×10 6 cells / mL. For example, it can be 1 ×10 6 cells / mL, 2 ×10 6 cells / mL, 3 ×10 6 cells / mL, 4 ×10 6 cells / mL, 5 ×10 6 cells / mL, or 6 ×10 6 cells / mL.

[0097] In some embodiments, the mass-volume ratio of the photoinitiator to solvent water is (0.1-1) g / 100 mL; for example, it can be 0.1 g / 100 mL, 0.2 g / 100 mL, 0.25 g / 100 mL, 0.3 g / 100 mL, 0.5 g / 100 mL, 0.6 g / 100 mL, 0.8 g / 100 mL, or 1 g / 100 mL, and further, it can be (0.25-0.5) g / 100 mL. Further, the photoinitiator comprises lithium phenyl (2,4,6-trimethylbenzoyl) phosphate (LAP for short).

[0098] In a specific example, the cell suspension is prepared as follows: 5%-12% (w / v) GelMA aqueous solution containing 0.1-1% (w / v) LAP is filtered through a 0.22-μm filter to remove bacteria, and then mixed with cells to obtain a cell suspension with a cell concentration of (1-6) ×10 6 cells / mL. It should be noted that (w / v) in the embodiments of the present application refers to the mass-volume ratio, and the unit is g / mL, and the volume refers to the volume of the solvent, for example, the volume of water.

[0099] In some embodiments, the degradable polymer material comprises polycaprolactone with a molecular weight of 10,000 to 1,000,000; the preparation raw material of the hydrogel material matrix comprises methacrylated gelatin; and the photoinitiator comprises phenyl (2,4,6-trimethylbenzoyl) lithium phosphate.

[0100] In some embodiments, the intensity of the ultraviolet light for ultraviolet curing crosslinking is 10 mW / cm 2 ~30 mW / cm 2 , for example, 10 mW / cm 2 , 15 mW / cm 2 , 20 mW / cm 2 , 25 mW / cm 2 , 30 mW / cm 2 ; further, 10 mW / cm 2 ~15 mW / cm 2 In some embodiments, the processing time for ultraviolet curing crosslinking is 10 s to 60 s, for example, 10 s, 20 s, 30 s, 40 s, 50 s, or 60 s. In some embodiments, the wavelength of the ultraviolet light used for ultraviolet curing crosslinking can be 405 nm.

[0101] In some embodiments, before the step S23 of applying the cell suspension, the following step is further included: the polymer porous scaffold prepared in the step S22 is soaked in an alkaline solution for surface etching to form a concave-convex surface structure. The ribs of the polymer porous scaffold thus formed have a concave-convex surface structure. The concave-convex surface structure on the ribs is conducive to the adsorption and adhesion of the hydrogel preparation raw material and the seed cells in the cell suspension, and is conducive to improving the mechanical properties of the medical implant.

[0102] Further, the alkaline solution includes but is not limited to sodium hydroxide solution, and the concentration of the alkaline solution can be 1 to 10 mol / L, and the etching time can be 0.3 to 12 h of oscillation.

[0103] Further, the specific steps of surface etching include: completely immersing the polymer porous scaffold in a 1 to 10 mol / L NaOH solution, and then oscillating at 100 to 500 rpm for 0.3 to 12 h. After the end, washing with sterile deionized water for 3 times, each for 15 min, and then washing with sterile phosphate buffer for 3 times, each for 15 min. After natural air drying, ultraviolet irradiation for 12 h is used for sterilization.

[0104] In some embodiments, the filling volume ratio of the hydrogel composite material in the medical implant is 44% to 55%.

[0105] In some embodiments, the hydrogel composite has a filling volume ratio in the medical implant comparable to the porosity of the polymer porous scaffold. In actual operation, the amount of cell suspension applied is determined by the amount of infiltration of the entire pores of the polymer porous scaffold or the upper surface of the polymer porous scaffold.

[0106] Another embodiment of the present application also provides an artificial knee joint comprising any of the medical implants described above, and the medical implant serves as an artificial meniscus of the artificial knee joint.

[0107] In some embodiments, the medical implant can be a medial meniscus and / or a lateral meniscus.

[0108] In some embodiments, the artificial knee joint can further comprise at least one of a femoral prosthesis, a tibial prosthesis, and a patellar prosthesis. The artificial knee joint comprises a femoral prosthesis, a tibial prosthesis, and a patellar prosthesis. There is a cartilage disc between the femoral prosthesis and the tibial prosthesis, respectively referred to as the medial meniscus and the lateral meniscus.

[0109] In order to make the purpose, technical scheme and advantages of the present application more concise and clear, the present application is described by the following specific embodiments, but the present application is not limited to these embodiments. The embodiments described below are only better embodiments of the present application, which can be used to describe the present application, and cannot be understood as limiting the scope of the present application. It should be noted that any modification, equivalent replacement and improvement made within the spirit and principle of the present application shall be included in the protection scope of the present application.

[0110] In order to better illustrate the present application, the content of the present application is further described below in combination with embodiments. The following are specific embodiments.

[0111] 1.1 Preparation of carbon nanotube / polycaprolactone composite (CNT / PCL)

[0112] 25 mg, 50 mg, 100 mg of CNT (carbon nanotube, MACKLIN) were added to 50 mL of dichloromethane and ultrasonicated for 5-20 min to obtain a CNT solution. Then 5 g of PCL (polycaprolactone, MACKLIN) was added to the CNT solution and shaken at a speed of 200 rpm for 6 h to obtain a mixed solution. The mixed solution was naturally air-dried and then dried in a vacuum oven at room temperature for 4 h. Finally, the product was named according to the mass ratio of CNT and PCL.

[0113] Table 1

[0114]

[0115] 1.2 Design of 3D-printed meniscus model

[0116] The meniscus model is designed according to the native meniscus of the organism. The medial meniscus is shaped like an "O", and the lateral meniscus is shaped like a "C". The 3D graph of the bionic meniscus of a rabbit is shown in FIG. 1. Figure 1

[0117] 1.3 Printing of meniscus polymer porous scaffold

[0118] A high-temperature melt extrusion 3D printing method (fused deposition modeling technology, FDM) is used to print a bionic meniscus polymer porous scaffold (CNT / PCL porous scaffold) according to the 3D model of the bionic meniscus. The product is shown in FIG. 2. Figure 1 Figure 2 The printing material is CNT / PCL prepared in step 1.1 above.

[0119] In order to provide a hydrogel and a cell growth space, the meniscus scaffold is a porous scaffold. The printing conditions are as follows: extrusion temperature: 60-100 ℃, extrusion speed: 0.01-0.3 mm / s, printing speed: 1-10 mm / s, platform temperature: 25-50 ℃, printing nozzle inner diameter (i.e. filament diameter): 0.1-0.5 mm, and filament spacing (i.e. porous pore size): 0.3-1 mm.

[0120] 1.4 Preparation of methacrylated gelatin (GelMA)

[0121] 10 g of gelatin was completely dissolved in 100 mL of Carbonate-bicarbonate solution (12.5 mM sodium bicarbonate + 87.5 mM sodium carbonate) at 50-55 ℃ to obtain a gelatin solution.

[0122] MA was added to the gelatin solution at a ratio of methacrylic anhydride (MA): gelatin = 0.05-0.3 mL: 1 g, and then reacted at 50-55 ℃ under stirring at 400-600 rpm for 1-3 h. The pH of the solution was adjusted to 7.4 using 1 M HCl to terminate the reaction. The supernatant was collected by centrifugation at 4000 rpm for 5-10 min at room temperature, and then the supernatant was dialyzed using a 14 kDa dialysis membrane at 40 ℃ for 72 h, and finally freeze-dried to obtain GelMA.

[0123] 1.5 Method for preparing a composite meniscus scaffold (artificial meniscus)

[0124] ​​Pre-treatment of CNT / PCL scaffold: The porous polymer scaffold prepared in 1.3 was completely immersed in 1-10 mol / L NaOH solution, and then oscillated at 100-500 rpm for 0.3-12 h. After the end, it was washed with sterile deionized water for 3 times, 15 min each time, and then washed with sterile phosphate buffer for 3 times, 15 min each time. After natural air drying, it was sterilized by ultraviolet irradiation for 12 h.

[0125] Preparation of cell-containing GelMA solution: 5%-12 % (w / v) GelMA containing 0.1-1% (w / v) LAP (Chinese: phenyl(2,4,6-trimethylbenzoyl) lithium phosphate salt) was sterilized by 0.22 μm filter membrane, and then mixed with cells to obtain a cell suspension with a cell concentration of (1-6) x 10 6 cells / mL.

[0126] The type of cells in the cell-containing GelMA solution is selected as needed, and in a specific example, umbilical cord stem cells are used as seed cells. The extraction and culture scheme of umbilical cord mesenchymal stem cells is as follows: human umbilical cord tissue is taken from a woman who delivered on the same day, and stored in α-MEM at 4 ℃ for 12-18 hours. Then the umbilical cord tissue is soaked with 70% alcohol for 15-60 seconds, and then rinsed with PBS for three times. After removing the three blood vessels in the umbilical cord, the Wharton's jelly in the umbilical cord is taken and cut into small pieces with a width of 2-6 mm. The cut Wharton's jelly fragments are rinsed with PBS for 3 times, and then the tissue fragments are placed in a culture dish and cultured with αMEM medium containing 10% FBS, 2 mM L-glutamine and 100 U / ml penicillin / streptomycin. The medium is changed twice a week. When the confluence of cells in the dish is about 80-90%, digest with 0.25% trypsin-EDTA for 5 minutes and subculture. When the cells are subcultured to the fourth generation, they are digested with trypsin for standby.

[0127] Preparation of composite meniscus scaffold: The cell suspension was added dropwise to the polymer meniscus scaffold, and after the suspension filled the entire meniscus pores, the meniscus scaffold surface cell suspension was removed. After the solution was completely cross-linked by 405 nm ultraviolet light irradiation (ultraviolet light intensity was 15 mW / cm 2 , treatment time was 60 s).

[0128] Example 1

[0129] Step 1.2 and 1.3 were performed with 0.5CNT / PCL compounded in Step 1.1, wherein the printing conditions in Step 1.3 were: extrusion temperature: 95 ℃, extrusion speed: 0.15 mm / s, printing speed: 5 mm / s, platform temperature: 30 ℃, printing nozzle inner diameter (i.e. filament diameter): 0.3 mm, filament spacing (i.e. pore diameter): 0.7 mm; a polymer porous scaffold was obtained.

[0130] Step 1.4 was performed with the polymer porous scaffold prepared above, wherein the ratio of methacrylic anhydride (MA) to gelatin was 0.15 mL: 1 g, the reaction was performed at 52 ℃ for 2 h under 500 rpm stirring; the solution was adjusted to pH 7.4 with 1 M HCl to terminate the reaction; the supernatant was collected by centrifugation at 4000 rpm for 8 min at room temperature, and then the supernatant was dialyzed at 40 ℃ for 72 h using a 14 kDa dialysis membrane, and finally freeze-dried to obtain GelMA.

[0131] Step 1.5 was as follows.

[0132] CNT / PCL scaffold pretreatment: the polymer porous scaffold prepared in Step 1.3 was completely immersed in a 5 mol / L NaOH solution, and then oscillated at 300 rpm for 6 h. After completion, it was washed 3 times with sterile deionized water for 15 min each time, and then washed 3 times with sterile phosphate buffer for 15 min each time. After natural air drying, it was sterilized by ultraviolet irradiation for 12 h.

[0133] Cell-containing GelMA solution preparation: GelMA was dissolved in a PBS solution containing 0.45% (w / v, g / mL) LAP (Chinese: phenyl (2,4,6-trimethylbenzoyl) lithium phosphate) to obtain a 10% (w / v, g / mL) GelMA solution; then, after sterilization by filtration with a 0.22 μm filter, it was mixed with cells to obtain a cell suspension with a cell concentration of 4×10 6 cells / mL; wherein the cells were umbilical cord stem cells.

[0134] Compound meniscus scaffold preparation: the above cell suspension was added dropwise to the polymer meniscus scaffold, and after the suspension filled the entire meniscus pores, the cell suspension on the surface of the meniscus scaffold was removed. After the solution was completely cross-linked by 405 nm ultraviolet light irradiation (ultraviolet light intensity was 15 mW / cm 2 , treatment time was 60 s).

[0135] Example 2

[0136] It was basically the same as Example 1, except that Step 1.2 and 1.3 were performed with 1CNT / PCL compounded in Step 1.1.

[0137] Example 3

[0138] The same as Example 1, except that the step 1.2 and 1.3 were performed with the composite 2CNT / PCL prepared in step 1.1.

[0139] Example 4

[0140] The same as Example 2, except that the step 1.5 of CNT / PCL scaffold pretreatment in NaOH solution was not performed before the cell suspension was added in Example 4.

[0141] Comparative Example 1

[0142] The same as Example 1, except that the step 1.2 and 1.3 were performed with the pure PCL without composite prepared in step 1.1.

[0143] Comparative Example 2

[0144] The same as Example 2, except that the preparation process of the polymer meniscus scaffold used in Comparative Example 2 was different, which was as follows:

[0145] The printing conditions of fused deposition modeling included: extrusion temperature: 95 ℃, extrusion speed: 0.15 mm / s, printing speed: 5 mm / s, platform temperature: 30 ℃, printing nozzle inner diameter (i.e. filament diameter): 0.3 mm, and filament spacing was 0.3 mm.

[0146] Table 2

[0147]

[0148] The following is the performance test.

[0149] (I) The CNT / PCL prepared in step 1.1 was subjected to the following performance tests.

[0150] 1) The chemical structure was characterized by Fourier infrared spectroscopy.

[0151] The results are shown in Table 2. Figures 3 to 6 As shown in Table 2, there was no significant difference in the Fourier infrared spectroscopy results of PCL, 0.5CNT / PCL, 1CNT / PCL and 2CNT / PCL, which was mainly due to the overlapping of the characteristic peak position of CNT and the characteristic peak position of PCL, and also indicated that the introduction of CNT would not change the chemical structure of PCL.

[0152] 2) The mechanical properties were characterized by a universal mechanical testing machine.

[0153] The CNT / PCL material was prepared into standard test bars, and then its mechanical properties were examined by tensile test, and the results are shown in the following table.

[0154] Table 3

[0155]

[0156] As known from the above table, the addition of CNTs significantly improves the Young's modulus, elongation at break and breaking strength of PCL, and with the increase of CNTs, the mechanical properties such as Young's modulus, elongation at break and breaking strength are gradually improved. After the PCL material is prepared into a porous scaffold, its mechanical properties are highly matched with the mechanical properties of human meniscus. However, the pressure on the meniscus during the movement of a person can be as high as 10 times the body weight of the person, so higher requirements are needed for the mechanical properties of the meniscus scaffold. Therefore, compared with PCL, CNT / PCL can be better applied in the field of meniscus repair.

[0157] 3) Degradation performance was verified by accelerated degradation through immersion in 2.5 M NaOH or 0.1 M HC1 solution.

[0158] The degradation performance of the above PCL and different CNT / PCL test bars was characterized by accelerated degradation by immersion in 2.5 M NaOH solution. The immersion conditions were: 37±1 ℃, 200 rpm, immersion liquid volume (mL): test sample weight (g) = 30. After immersion for 3 d, 7 d and 14 d, 3 samples were taken out from each group to calculate the weight loss rate, and the calculation formula was (W0-W1) W0*100%, wherein W0 was the original sample dry weight, and W1 was the sample dry weight after immersion.

[0159] The results are shown in Figure 7 As the immersion time increases, the weight loss of the four samples also increases. After immersion for 3 d and 7 d, there is no significant difference in the weight loss rate between the four samples, and the weight loss rate of 1CNT / PCL is lower than that of the other samples; after immersion for 14 d, the weight loss rate of 2CNT / PCL is significantly higher than that of PCL, and there is no significant difference in the weight loss rate between the other samples, and the weight loss rate of 1CNT / PCL is lower than that of the other samples. It shows that CNTs can slow down the degradation rate of PCL to a certain extent at a certain addition amount.

[0160] 4) Cytotoxicity of CNT / PCL

[0161] The cytotoxicity of CNT / PCL was characterized by detecting the cytotoxicity of its leaching liquor.

[0162] Sample extraction: CNT / PCL materials (samples) were prepared into thin films and immersed in α-MEM medium (PM150410, Procell) containing 10% serum. The sample (g): medium (mL) = 1:30. The immersion conditions were 37 °C, 200 rpm shaking, 24 h. The extraction solution was collected, 0.22 μm filtered to remove bacteria, and stored at 4 °C for later use.

[0163] Cytotoxicity test: MC3T3-E1 cells (Procell) were seeded in 96-well plates at a density of 10000 cells / cm 2 . After overnight culture, the medium was removed and 100% extraction solution (i.e., the extraction solution directly extracted by the above steps) was added. After 1 and 3 days of culture, the number of cells was detected by CCK8 kit. The pure medium group was used as a control group (Control group).

[0164] The results are shown in Figure 8 . After 1 day of culture of the extraction solution, all concentrations of sample extraction solution had no cytotoxicity. The cytotoxicity of 100% extraction solution of 1CNT / PCL was significantly lower than that of 100% extraction solution of 0.5CNT / PCL and PCL. The above indicates that the mass content of CNT of 1% is beneficial to reduce the cytotoxicity of PCL.

[0165] As shown below Figure 9 , after 3 days of culture of the extraction solution, all concentrations of sample extraction solution had no significant difference from the control group. The 100% extraction solution of all CNT / PCL samples containing CNT had a promoting effect on cell growth compared with the 100% extraction solution of PCL. The above results indicate that the content of CNT of 0.5%~2% is beneficial to cell proliferation.

[0166] (II) The following performance tests were performed on the methyl methacrylate gelatin (GelMA) prepared in step 1.4.

[0167] 1) Physicochemical properties of GelMA

[0168] 5% (w / v) GelMA, 10% (w / v) GelMA, and 10% (w / v) GelMA+MC3T3-E1 cells (concentration of 2×10 6 cells / mL) containing 0.25 wt% LAP PBS solution were prepared, respectively. A 25 mm plate clamp was used for testing on a rotational rheometer. The mechanical strength of the hydrogel after cross-linking of the GelMA solution was detected by the rheometer.

[0169] (a) Test conditions: 25 °C, 100 μm gap, frequency 0.1 Hz and strain 0.5%, 0-50 s without UV light, 50-150 s with UV light (405 nm). This experiment was used for 5 % (w / v) GelMA, 10 % (w / v) GelMA solution.

[0170] The results are shown in Figure 6 (abscissa is UV irradiation time s, ordinate is the stiffness G' (Pa) of the GelMA solution), showing the change of the stiffness of 5 % and 10 % (w / v) GelMA solution with the increase of UV irradiation time. It can be seen from the figure that the stiffness of 5 % and 10 % (w / v) GelMA solution after UV irradiation is 0.8 KPa and 18 KPa, respectively. Figure 10

[0171] (b) Test conditions: 18-23 °C, 1000 μm gap, frequency 0.1 Hz and strain 0.5%. This experiment was used for 10 % (w / v) GelMA and 10 % (w / v) GelMA + MC3T3-E1 cells solution.

[0172] The results are shown in Figure 7 (abscissa is temperature / °C, ordinate is viscosity / mPa-s), showing the change of the viscosity of 10 % (w / v) GelMA solution and 10 % (w / v) GelMA + MC3T3-E1 cells solution with the change of temperature. The results show that the viscosity of 10 % (w / v) GelMA solution without cells will increase significantly with the decrease of temperature, and the addition of cells will reduce the viscosity of GelMA solution below 20.5 °C, and will increase the viscosity of GelMA solution above 20.5 °C. Figure 11

[0173] (c) Test conditions: 23 °C, 100 μm gap, frequency 0.1 Hz and strain 0.5%, 0-50 s without UV light, 50-150 s with UV light (405 nm, 15-30 mW / cm 2 ). This experiment was used for 10 % (w / v) GelMA and 10 % (w / v) GelMA + MC3T3-E1 cells solution.

[0174] The results are shown in Figure 8 (abscissa is UV irradiation time s, ordinate is the stiffness G' (Pa) of the GelMA solution), showing the change of the stiffness of 10 % (w / v) GelMA and 10 % (w / v) GelMA + MC3T3-E1 cells solution with the increase of UV irradiation time. It can be seen from the figure that the stiffness of 10 % (w / v) GelMA and 10 % (w / v) GelMA + MC3T3-E1 cells solution after UV irradiation is 18 KPa and 20 KPa, respectively. Figure 12 ​​The rigidity of 10 % (w / v) GelMA + MC3T3-E1 cells solution changes with the increase of different intensity UV irradiation and different UV irradiation time. It can be seen from the figure that the addition of cells reduces the rigidity of 10 % (w / v) GelMA solution from 18 KPa to 11 KPa, and the higher the intensity of ultraviolet light, the faster the rigidity of GelMA solution reaches the maximum value, that is, the faster the gelation speed. The rigidity of cartilage is 10 KPa, so the 10 % (w / v) GelMA hydrogel containing cells provides an ideal mechanical environment for the cells inside for the regeneration and repair of cartilage-like defects.

[0175] 2) Cell compatibility test of GelMA hydrogel

[0176] (a) Cell two-dimensional culture test: 1000 mg of GelMA was dissolved in 10 mL of PBS solution containing 0.1-0.25 % (w / v) LAP. After sterilization by 0.22 μm filter, the solution was added to the 24-well plate to ensure that the solution completely covered the well plate, and each solution was added to 3 wells; after crosslinking and gelling of the solution by 405 nm ultraviolet light irradiation, 500 μL of α-MEM medium (PM150410, Procell) was added to each well, and the solution was incubated at 37 °C in a 5 % CO2 environment for 5 min; the medium was removed, and 1 mL of α-MEM medium containing 2×10 4

[0177] The cell two-dimensional culture results are shown in Figure 13 , which are the light microscope results of MC3T3-E1 cells cultured on the surface of GelMA hydrogel and the surface of the culture plate for 2 days. As shown in Figure 13 , the cells are very healthy on the surface of the two materials and can normally adhere to the surface of the substrate material and grow, indicating that the 10 % (w / v) GelMA hydrogel has no cytotoxicity.

[0178] (b) Cell three-dimensional culture test: 5 %, 6.6 % and 10 % (w / v) GelMA were mixed with MC3T3-E1 cells to obtain a cell concentration of (2)×10 6 ​The cell suspension was added to a 24-well plate to ensure that the solution completely covered the well plate, and the same solution was added to three wells, respectively. After the two solutions of GelMA hydrogel and cell suspension were cross-linked into glue by 405 nm ultraviolet light irradiation, 500 μL of α-MEM medium containing 10 % FBS and 1 % P / S was added to each well, and the medium was removed after standing for 5 min at 37 °C in a 5 % CO2 environment; then 800 μL of fresh α-MEM medium containing 10 % FBS and 1 % P / S was added, and the cells were cultured at 37 °C in a 5 % CO2 environment for 3 days, and then the cell growth was observed by live and dead staining agent (CA1630-500T, Solarbio).

[0179] The results of three-dimensional cell culture are shown in FIG. 2, which are the staining results of MC3T3-E1 cells cultured in three different concentrations (5 % (w / v) (left), 6.6 % (w / v) (middle) and 10 % (w / v) (right)) of GelMA hydrogel for 3 days. The results show that there are only a few dead cells in the three hydrogels, indicating that the three hydrogels have no obvious toxicity to the cells, and the cells grow best in the 5 % (w / v) GelMA hydrogel, with more tentacles growing out of the spherical shape, and the cells in the 5 % (w / v) GelMA hydrogel have a larger volume compared with the cells in the other two hydrogels; the cells grow in a spherical shape in the 6.6 % and 10 % (w / v) GelMA hydrogels, which is due to the fact that the 5 % (w / v) GelMA hydrogel has a larger growth space that is conducive to the extension growth of the cells. However, the 5 % (w / v) GelMA hydrogel has a low stiffness, which is not conducive to the chondrogenic differentiation of the cells. Figure 14

[0180] (Three) The composite meniscus scaffolds (artificial menisci) prepared in Examples 1-4 and Comparative Examples 1-2 were subjected to performance tests.

[0181] Based on the test results of (One) and (Two) above, the hydrogel with a GelMA concentration of 10 % (w / v) was selected to construct a cell microenvironment, umbilical cord mesenchymal stem cells were selected as seed cells, and 0.5 CNT / PCL and 1 CNT / PCL were selected as high molecular scaffold materials to construct the composite tissue engineering meniscus scaffolds of Examples 1-4 and Comparative Examples 1-2; and in vitro biocompatibility tests were performed.

[0182] ​The in vitro biocompatibility test subjects for the artificial meniscus were Comparative Examples 1-2 and Examples 1-4. The test steps were as follows: α-MEM medium (PM150410, Procell) containing 10% fetal bovine serum (SA220126, Procell, FBS) and 1% penicillin antibody (15140-122, Gibco, P / S) was added to completely submerge the artificial meniscus scaffold prepared above. After standing for 5 min at 37°C and 5% CO2, the medium was removed, and then 800 μL of fresh α-MEM medium containing 10% FBS and 1% P / S was added. After culturing for 7 days at 37°C and 5% CO2, cell growth was observed using a live / dead staining agent.

[0183] The growth of umbilical cord mesenchymal cells after 7 days of culture in the GelMA / PCL scaffolds prepared in Comparative Example 1 and the GelMA / CNT / PCL scaffolds prepared in Examples 1-2 is shown in the figure. Figure 15 As shown; where GelMA / PCL (Comparative Example 1, left), GelMA / 0.5CNT / PCL (Example 1, middle) and GelMA / 1CNT / PCL (Example 2, right).

[0184] Depend on Figure 15 It can be seen that the cells grew well within the CNT-containing scaffolds of Examples 1 and 2, and the CNT / PCL scaffolds bound the cells well. Furthermore, with increasing CNT content, the cells were more evenly distributed on the CNT / PCL scaffolds, indicating better cell adhesion and migration. Conversely, there was only minimal direct contact between the cells and PCL, indicating poor cell growth within the GelMA / PCL scaffold of Comparative Example 1, resulting in smaller cell volume.

[0185] As can be seen from the above, the GelMA / CNT / PCL composite meniscus scaffold used in this application has excellent mechanical properties, degradation performance and good cell compatibility, and is expected to solve the problems of poor mechanical properties, minimal degradation and unfavorable cell growth of meniscus products, and has great application prospects.

[0186] The growth of umbilical cord mesenchymal cells after 7 days of culture in the GelMA / CNT / PCL scaffolds prepared in Comparative Example 2 and Examples 2 and 4 is shown in the figure. Figure 16 As shown; among them, Example 2 (GelMA / 1CNT / PCL, left), Example 4 (untreated GelMA / 1CNT / PCL, middle), and Comparative Example 2 (non-porous scaffold, right).

[0187] from Figure 16It can be seen that the cells of Example 2 and Example 4 grew well on the meniscus scaffold CNT / PCL whether or not the scaffold was pretreated with NaOH solution; but the cells of Example 2, which was pretreated with NaOH solution, distributed more evenly on the CNT / PCL scaffold, and the adhesion ability of the cells was enhanced. The meniscus scaffold prepared in Comparative Example 2 by fused deposition molding process with the inner diameter of the printing nozzle equal to the distance between the filaments could not form a network structure, i.e. the scaffold was not a porous structure, and the test showed that no cells were found inside the non-porous meniscus scaffold, indicating that the cells could not pass through the scaffold and enter the interior of the scaffold.

[0188] The technical features of the above-described embodiments can be combined in any manner. To make the description concise, all possible combinations of the technical features in the above-described embodiments are not described, but as long as the combinations of the technical features do not contradict each other, they should be considered within the scope of the present disclosure.

[0189] The above-described embodiments only express several implementation manners of the present application, and the description is relatively specific and detailed, but it should not be understood as a limitation on the scope of the patent. It should be pointed out that for those skilled in the art, some modifications and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application should be subject to the appended claims, and the description and drawings can be used to explain the content of the claims.

Claims

1. A medical implant, characterized in that The medical implant comprises a high-molecular porous scaffold and a hydrogel composite filled in the pores of the high-molecular porous scaffold, the material of the high-molecular porous scaffold comprises a degradable high-molecular material and carbon nanotubes distributed in the degradable high-molecular material, and the hydrogel composite comprises a hydrogel material matrix and seed cells distributed in the hydrogel material matrix.

2. The medical implant of claim 1, wherein The high-molecular porous scaffold comprises a plurality of ribs interconnected to form a three-dimensional network structure.

3. The medical implant of claim 2, wherein The ribs have a concave-convex surface structure.

4. The medical implant according to any of claims 1 to 3, characterized in that The medical implant satisfies at least one of the following characteristics: (1) the degradable high-molecular material comprises at least one of polycaprolactone, polyurethane, polylactic acid, poly(lactic-co-glycolic acid), poly(lactic-co-caprolactone) and polyglycolic acid; (2) the raw material for preparing the hydrogel material matrix comprises one or more of methacrylated gelatin, collagen, chitosan, hyaluronic acid and sodium alginate; (3) the high-molecular porous scaffold is formed by 3D printing; (4) the filling volume ratio of the hydrogel composite in the medical implant is 44% to 55%; (5) the mass ratio of the carbon nanotubes to the degradable high-molecular material is (0.2-2):100; (6) the porosity of the high-molecular porous scaffold is 44% to 55%.

5. The medical implant of claim 4, wherein The medical implant satisfies at least one of the following characteristics: (1) the degradable high-molecular material comprises polycaprolactone, and the molecular weight of the polycaprolactone is 10,000 to 10 million; (2) the 3D printing comprises a fused deposition modeling technology.

6. The medical implant according to any of claims 1 to 3, 5, characterized in that The medical implant satisfies at least one of the following characteristics: (1) the seed cells comprise at least one of embryonic stem cells, umbilical cord mesenchymal stem cells, bone marrow mesenchymal stem cells and chondrocytes; (2) the medical implant is an artificial meniscus.

7. A method of manufacture for the manufacture of a medical implant according to any one of claims 1 to 6, characterized in that, The method comprises the following steps: mixing a dispersion liquid of the carbon nanotubes with the degradable high-molecular material, drying to prepare a high-molecular composite material; using the high-molecular composite material as a raw material to prepare a high-molecular porous scaffold; applying a cell suspension for forming the hydrogel composite to the high-molecular porous scaffold, and then performing ultraviolet curing crosslinking to obtain the medical implant; the cell suspension comprises a hydrogel preparation raw material, seed cells and a photoinitiator.

8. The production method according to claim 7, wherein The preparation method satisfies at least one of the following characteristics: (1) before applying the cell suspension, the method further comprises the following step: immersing the high-molecular porous scaffold in an alkaline solution for surface etching to form a concave-convex surface structure; (2) using the high-molecular composite material as a raw material to form the high-molecular porous scaffold by 3D printing; (3) in the step of preparing a polycaprolactone composite material, the mass ratio of the carbon nanotubes in the carbon nanotube dispersion liquid to the polycaprolactone is (0.2-2):

100.

9. The production method according to claim 7, wherein The preparation method satisfies at least one of the following characteristics: (1) the 3D printing is a fused deposition modeling technology; the printing condition of the 3D printing includes: an extrusion temperature of 60-100 DEG C, an extrusion speed of 0.01-0.3 mm / s, a printing speed of 1-10 mm / s, a platform temperature of 25-50 DEG C, a printing nozzle inner diameter of 0.1-0.5 mm, and a diameter wire spacing of 0.3-1 mm, wherein the printing nozzle inner diameter is less than the diameter wire spacing; (2) The ultraviolet light intensity of the ultraviolet curing crosslinking is 10 mW / cm 2 30 mW / cm 2 , and the processing time is 40 s~60 s.

10. The production method according to any one of claims 7 to 9, wherein The preparation method satisfies at least one of the following characteristics: (1) the mass-volume ratio of the hydrogel preparation monomer to solvent water in the cell suspension is (5-12) g / 100 mL, the concentration of the seed cells is (1-6) x 10 6 cells / mL, and the mass-volume ratio of the photoinitiator to solvent water is (0.1-1) g / 100 mL; (2) the mass-volume ratio of the hydrogel preparation monomer to solvent water in the cell suspension is (5-12) g / 100 mL, the concentration of the seed cells is (1-6) x 10 6 cells / mL, and the mass-volume ratio of the photoinitiator to solvent water is (0.1-1) g / 100 mL; (2) the degradable high molecular material includes polycaprolactone, and the molecular weight of the polycaprolactone is 10-1,000,000; (3) the hydrogel preparation raw material includes one or more of methyl methacrylate gelatin, collagen, chitosan, hyaluronic acid and sodium alginate; (4) the photoinitiator includes a phenyl (2,4,6-trimethylbenzoyl) lithium phosphate salt; (5) the application amount of the cell suspension is determined according to the infiltration of all pores of the high molecular porous scaffold or the upper surface of the high molecular porous scaffold.

11. A prosthetic knee joint, characterized in that The medical implant of any one of claims 1-6 is used as an artificial meniscus of the artificial knee joint.

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