Bioactive glass-based composite multilayer cartilage scaffold and preparation method thereof
Through the 3D printing technology of bioactive glass-based composite multi-layer cartilage scaffolds, the problems of high brittleness and low toughness in the prior art are solved, and higher mechanical properties and biocompatibility are achieved, and artificial cartilage repair is suitable.
Patent Information
- Application Number
- CN202411728644.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-28
- Publication Date
- 2025-02-14
AI Technical Summary
In the prior art, cartilage has high brittleness and low toughness, which leads to the easy loosening and wear of artificial cartilage repair materials, making it difficult to effectively repair large defects.
Using bioactive glass-based composite multi-layer cartilage scaffolds, prepared by 3D printing technology, the material composition includes the subchondral bone layer, the cartilage transition layer and the clear cartilage layer. The porosity and component ratio of each layer are optimized to improve the overall mechanical performance.
The excellent wear resistance, tension and durability of the cartilage stent is achieved, and the looseness and wear of the repair material is avoided, and large defects can be effectively repaired, and the biocompatibility is good.
Smart Images
Figure CN119424747A_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the field of biomedical technology, and in particular relates to a bioactive glass-based composite multi-layer cartilage scaffold and a preparation method thereof. Background Art
[0002] Cartilage is the most difficult structure to heal in the human body. The main function of cartilage is to relieve pressure and act as an elastic cushion to protect the bones under the cartilage from damage. Diseases such as joint trauma and inflammation often cause articular cartilage damage. After articular cartilage damage, the regeneration capacity is limited and it is difficult to repair itself. Even relatively small cartilage damage may produce more obvious symptoms such as pain, swelling, and dysfunction, and eventually joint degeneration. Current clinical methods for treating cartilage damage, such as drug therapy or joint cleaning, can only temporarily relieve pain and cannot cure it; autologous bone transplantation is a traumatic treatment method with good treatment effects, but the source is limited and it cannot repair large defects; allogeneic bone transplantation also has the problem of insufficient sources and is prone to rejection; artificial cartilage is mostly made of metal or ceramic materials, which are prone to loosening and wear after implantation.
[0003] With the rapid development of tissue engineering technology in recent years, people can transplant tissue engineering scaffolds. The ideal tissue engineering scaffold should have good biocompatibility, plasticity, moderate biodegradability and three-dimensional structure, as well as excellent wear resistance, tension resistance and durability. Due to the different pathological mechanisms of cartilage damage in patients, the thickness, texture, structure and biomechanical properties of cartilage in different parts of the body, there are obvious individual differences in human cartilage repair.
[0004] Bioactive glass is a type of biomaterial with excellent performance. It has good bioactivity and biocompatibility. It can effectively accelerate the migration of cells in the wound and upregulate the expression of vascular-related growth factors in the wound. In addition, it can promote the deposition of collagen in the wound, accelerate epithelialization and granulation formation, inhibit bacterial reproduction, and promote wound healing. The degradation products of bioactive glass can promote the production of growth factors / promote cell reproduction. However, bioactive glass is brittle, has low fracture toughness and mechanical strength, especially for layered artificial bones, which are prone to loosening, breaking and displacement between layers. Summary of the invention
[0005] The purpose of the present invention is to overcome the shortcomings of the above-mentioned prior art and provide a bioactive glass-based composite multi-layer cartilage scaffold and a preparation method thereof, so as to solve the defects of the prior art of high cartilage brittleness and low toughness, and provide a better solution for artificial cartilage repair.
[0006] In order to achieve the above object, the present invention adopts the following technical solutions: The first aspect of the present invention discloses a bioactive glass-based composite multi-layer cartilage scaffold, comprising a subchondral bone layer, a cartilage transition layer and a hyaline cartilage layer stacked in sequence from bottom to top; the subchondral bone layer is composed of bioactive glass and a binder, the cartilage transition layer is composed of bioactive glass, hydrogel and a binder; the hyaline cartilage layer is composed of a hydrogel and a binder.
[0007] A further improvement of the present invention is: Preferably, the porosity of the subchondral bone layer is 30% to 50%, the porosity of the cartilage transition layer is 50% to 80%, and the porosity of the hyaline cartilage layer is greater than 80%.
[0008] Preferably, in terms of mass fraction, the bioactive glass in the subchondral bone layer accounts for 65wt% to 86wt%, and the adhesive accounts for 14% to 35%.
[0009] Preferably, in terms of mass fraction, the bioactive glass and the hydrogel in the cartilage transition layer each account for 30 wt% to 55 wt%, and the binder accounts for 10% to 25%.
[0010] Preferably, in terms of mass fraction, the hydrogel in the hyaline cartilage layer accounts for 60 wt % to 90 wt %, and the binder accounts for 10% to 40%.
[0011] Preferably, the bioactive glass comprises SiO2, Na2O, CaO and P2O5.
[0012] Preferably, the hydrogel material is one or more of bacterial cellulose, sodium alginate, gelatin and chitosan.
[0013] Preferably, the bonding aid is one or more of polylactic acid, polyvinyl alcohol, silk fibroin, and collagen.
[0014] A method for preparing the above-mentioned bioactive glass-based composite multi-layer cartilage scaffold comprises the following steps: Obtaining a cartilage defect model; obtaining the tomographic data of the cartilage defect site of the patient through medical imaging, performing three-dimensional reconstruction through the tomographic data, and designing a model, wherein pores are set in the model, and saving the model in an STL format file; Prepare slurries; prepare printing slurry A, printing slurry B and printing slurry C respectively; the printing slurry A is composed of bioactive glass and a binder; the printing slurry B is composed of bioactive glass, hydrogel and a binder; the printing slurry C is composed of a hydrogel and a binder; 3D printing, loading the STL format file into a multi-nozzle extrusion bioceramic 3D printing device, installing three barrels respectively filled with printing slurry A, printing slurry B and printing slurry C on the printing head for printing; first printing the subchondral bone layer, then printing the cartilage transition layer, and finally printing the transparent cartilage layer; obtaining a cartilage scaffold blank; Post-processing: freeze-drying the cartilage scaffold blank and then cleaning it, sterilizing the cleaned cartilage scaffold blank, and finally obtaining a bioactive glass-based composite multilayer cartilage scaffold.
[0015] Preferably, during the 3D printing process, a dual-nozzle interactive printing method is used when printing the junction between the subchondral bone layer and the cartilage transition layer, and the junction between the cartilage transition layer and the hyaline cartilage layer.
[0016] Compared with the prior art, the present invention has the following beneficial effects: The present invention discloses a bioactive glass-based composite multi-layer cartilage scaffold. Natural cartilage has a multi-gradient structure, which is a hyaline cartilage layer, a cartilage transition layer and a subchondral bone layer in sequence. The three are both interconnected and different in components and structures. The present invention performs bionic design by combining materials and structures. The cartilage scaffold is prepared by 3D printing as a whole. The hyaline cartilage layer adopts hydrogel, the cartilage transition layer adopts a composite material of bioactive glass and hydrogel, and the subchondral bone layer adopts a bioactive glass material. The multi-layer cartilage scaffold with a gradient structure as a whole is designed, so that the similarity between materials is high and it is closer to natural cartilage. Compared with traditional cartilage implants, in addition to having good biocompatibility, it has excellent wear resistance, tension resistance and durability, can effectively avoid loosening and wear of repair materials, and can avoid fracture and loosening between layered structures. The present invention customizes and designs a cartilage scaffold with a composite of multi-layer and gradient porous structures in combination with the cartilage defect site and individual characteristics of the patient. It matches the cartilage structure of the human body, realizes the dual bionics of materials and structures, and enhances the repair effect of the cartilage scaffold. Compared with biomaterials with a single component or structure, the performance of biocomposite materials is adjustable. In order to overcome the defects of bioactive glass in mechanical properties, the present invention composites bioglass with other biomaterials, and utilizes the composite effect to make the material have good mechanical properties while maintaining excellent biocompatibility. A composite multilayer cartilage scaffold is prepared using bioactive glass as a substrate using 3D printing technology. After implantation, it has good biocompatibility and does not cause inflammatory response. Its mechanical properties such as elastic modulus, toughness and fracture strength are similar to those of human cartilage, and will not cause negative effects such as loosening and wear of repair materials caused by stress shielding, and can meet the clinical needs for cartilage repair.
[0017] Furthermore, bacterial cellulose is a porous mesh nano-scale biopolymer with good air permeability, water permeability and water retention properties, and has unique fiber mesh structure, high porosity, high mechanical strength and high elastic modulus. It is also an ideal scaffold for epithelial cell growth and an ideal alternative material for artificial skin, arterial veins, and bone tissue scaffolds. Bacterial cellulose is a cellulose with higher purity, which is easier to react with cellulose degrading enzymes. At the same time, it can also be directly degraded under natural conditions of acidity and the presence of microorganisms, so it has good biodegradability. Bacterial cellulose has high mechanical strength in humid conditions, good permeability to water and electrolytes, good biological adaptability, non-irritation, and can prevent bacterial infection.
[0018] The present invention also discloses a method for preparing a bioactive glass-based composite multilayer cartilage scaffold, the composite cartilage scaffold preparation method comprising: providing raw materials, the specific raw materials comprising bioactive glass, hydrogel material and bonding aid. The raw materials are printed according to the constructed model, first printing the bottom subchondral bone layer, then printing the cartilage transition layer, and finally printing the transparent cartilage layer. The present invention uses 3D printing manufacturing technology to print artificial bones, can customize implants according to patient needs, accurately control the complex structural shape of the implant, and achieve dual adaptation of the implant shape and mechanical properties to the human body's own bones.
[0019] Furthermore, the porous bioceramic artificial bone of the present invention adopts a multi-nozzle extrusion bioceramic 3D printing device, and adopts a double-nozzle interactive printing method at the junction of layers, so that the interface is closely connected to form a unified structure, so that the scaffold can effectively avoid the problem of loose interface while reflecting local differences and functionality. BRIEF DESCRIPTION OF THE DRAWINGS
[0020] Figure 1 This is a flow chart of the artificial bone production process of the present invention. DETAILED DESCRIPTION
[0021] The present invention is further described in detail below in conjunction with the accompanying drawings: In order to enable those skilled in the art to understand the characteristics and effects of the present invention, the following is a general description and definition of the terms and expressions mentioned in the specification and claims. Unless otherwise specified, all technical and scientific terms used in the text are the common meanings understood by those skilled in the art for the present invention. In the event of a conflict, the definition in this specification shall prevail.
[0022] In this document, unless otherwise specified, “includes,” “including,” “contains,” “has,” or similar terms cover the meanings of “consisting of” and “mainly consisting of,” for example, “A includes a” covers the meanings of “A includes a and other” and “A only includes a.”
[0023] The present invention will be further described below in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and are not intended to limit the scope of the present invention. In addition, it should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms fall within the scope limited by the appended claims of the application equally.
[0024] The following examples use conventional instruments and equipment in the art. The experimental methods in the following examples where specific conditions are not specified are usually carried out under conventional conditions or under conditions recommended by the manufacturer. The various raw materials used in the following examples are conventional commercial products unless otherwise specified, and their specifications are conventional specifications in the art. In the specification of the present invention and the following examples, unless otherwise specified, "%" means weight percentage, "part" means weight part, and ratio means weight ratio.
[0025] The present invention is further described in detail below in conjunction with specific steps: (1) Obtaining a cartilage defect model: Using medical imaging technology to obtain the DICOM data of the patient's cartilage defect site, and reconstructing the data in three dimensions. Combining the patient's cartilage defect site and individual characteristics, a morphologically matching cartilage defect model is designed, and different pore structures are designed in the model and saved as an STL format file; (2) Printing slurry preparation and processing: 1) Preparation of bioactive glass printing slurry: The bioactive glass and the binder are weighed and mixed according to a certain mass ratio, and a uniform printing slurry A is obtained after treatment; the bioactive glass accounts for 65wt%~86wt% in the printing slurry A, and the binder accounts for 14%~35%.
[0026] 2) Preparation of bioactive glass-hydrogel composite printing slurry: The bioactive glass, hydrogel and binder are weighed and mixed according to a certain mass ratio, and a uniformly mixed printing slurry B is obtained after treatment; in slurry B, the bioactive glass and hydrogel each account for 30wt%~55wt%, and the binder accounts for 10%~25%.
[0027] Preferably, the hydrogel material is one or more of bacterial cellulose, sodium alginate, gelatin, and chitosan; the bonding aid includes one or more of polylactic acid, polyvinyl alcohol, silk fibroin, and collagen.
[0028] 3) Hydrogel preparation: The hydrogel material and the binder are mixed in a certain mass ratio to form a printing slurry C, in which the hydrogel accounts for 60wt%~90wt% and the binder accounts for 10%~40%.
[0029] The hydrogel material is one or more of bacterial cellulose, sodium alginate, gelatin and chitosan; the bonding aid includes one or more of polylactic acid, polyvinyl alcohol, silk fibroin and collagen.
[0030] (3) 3D printing: The STL format file established for the cartilage defect model in (1) above is loaded into a multi-nozzle extrusion bioceramic 3D printing device, and then three barrels filled with different printing slurries are installed on the print head, and 3D printing is performed using the above-treated printing slurry. During the printing process, the subchondral bone layer structure is first printed, using slurry A for printing, with a porosity of 30%~50% gradient structure, and then the cartilage transition layer is printed, using slurry B for printing, with a porosity of 50%~80% gradient structure, and finally the transparent cartilage layer is printed, using slurry C for printing, with a porosity greater than 80% gradient structure. When printing the interface between the subchondral structure and the cartilage transition layer, and the cartilage transition layer and the transparent cartilage layer, a dual-nozzle interactive printing method should be adopted to make the interface tightly connected to form a unified structure.
[0031] In the above porosity design, the cartilage transition layer mainly focuses on mechanical properties, so its porosity is relatively small. When gradually transitioning to the hyaline cartilage layer, the focus is on cell proliferation. The increase in porosity is conducive to the exchange of oxygen and nutrients between cells in the tissue, promoting cell growth and reproduction.
[0032] (4) Post-freeze drying and cleaning: The printed composite multilayer cartilage scaffold is placed in a freeze dryer for freeze drying. After freeze drying, the cartilage scaffold is placed in sterile injection water for ultrasonic cleaning for 1 hour, and then placed in a freeze dryer for freeze drying. This process is repeated once.
[0033] (5) Sterilization packaging: The composite multi-layer cartilage scaffold is sterilized by low-temperature sterilization and then packaged.
[0034] In some embodiments of the present invention, the hydrogel material and the binder material in the printing slurry A, the printing slurry B and the printing slurry C are all made of the same material, and the composition of the bioactive glass is the same, so that the connectivity between the materials in the layers is better.
[0035] The following is further described in conjunction with specific embodiments.
[0036] Implementation Case 1: (1) Obtaining a solid model of bone defect: Use medical imaging technology to obtain the cross-sectional DICOM data of the patient's cartilage defect site, and reconstruct the data in three dimensions. Combined with the patient's cartilage defect site and individual characteristics, a morphologically matching cartilage defect model is designed. The model is designed with different pore structures and saved as an STL format file.
[0037] (2) Printing slurry preparation and processing: 1) Preparation of bioactive glass printing slurry: 40 g of bioactive glass (80%) and 10 g of 8% polyvinyl alcohol aqueous solution (20%) were mixed, and the mixture was placed in a slurry homogenizer for stirring. After the mixture was uniformly mixed, it was loaded into a barrel and degassed in a centrifuge to obtain a uniformly mixed printing slurry A; 2) Preparation of bioactive glass hydrogel composite printing slurry: Weigh a certain amount of polylactic acid and dissolve it in dichloromethane solution to obtain a polylactic acid solution with a mass concentration of 5%. Then mix 15g of polylactic acid solution (23%) with 23g of bioactive glass (36%) and 26g of bacterial cellulose (41%), and stir mechanically at a speed of 80r / min for 20min to obtain printing slurry B; 3) Preparation of hydrogel printing slurry: Weigh a certain amount of polylactic acid and dissolve it in dichloromethane solution to obtain a polylactic acid solution with a mass concentration of 5%. Then mix 15g of polylactic acid solution (26%) with 42g of bacterial cellulose (74%), and stir mechanically at a speed of 80r / min for 20min to obtain printing slurry C; (3) 3D printing: The STL format file established for the cartilage defect model in (1) above is loaded into a multi-nozzle extrusion bioceramic 3D printing device, and then three barrels filled with different printing slurries are installed on the print head, and 3D printing is performed using the above-treated printing slurry. During the printing process, the subchondral bone layer structure is first printed, using slurry A for printing, with a porosity of 30%~50% gradient structure, and then the cartilage transition layer is printed, using slurry B for printing, with a porosity of 50%~80% gradient structure, and finally the transparent cartilage layer is printed, using slurry C for printing, with a porosity greater than 80% gradient structure. At the junction, a dual-nozzle interactive printing method should be adopted to make the interface tightly connected to form a unified structure.
[0038] (4) Post-freeze drying and cleaning: The printed composite multilayer cartilage scaffold is placed in a freeze dryer for freeze drying. After freeze drying, the cartilage scaffold is placed in sterile injection water for ultrasonic cleaning for 1 hour, and then placed in a freeze dryer for freeze drying. This process is repeated once.
[0039] (5) Sterilization packaging: The composite multi-layer cartilage scaffold is sterilized by low-temperature sterilization and then packaged.
[0040] Implementation Case 2: (1) Obtaining a solid model of bone defect: Use medical imaging technology to obtain the cross-sectional DICOM data of the patient's cartilage defect site, and reconstruct the data in three dimensions. Combined with the patient's cartilage defect site and individual characteristics, a morphologically matching cartilage defect model is designed. The model is designed with different pore structures and saved as an STL format file.
[0041] (2) Printing slurry preparation and processing: 1) Preparation of bioactive glass printing slurry: Dissolve 10g of silk fibroin in 45ml of 9.3mol / l lithium bromide solution at 37℃ for 3h, inject the completely dissolved silk fibroin solution into a dialysis bag, dialyze in deionized water for 2d, change the water every 8h, remove the salt ions in the solution, and obtain a silk fibroin solution with a concentration of about 6%. Then add 43g of bioactive glass (68%) to 20g of silk fibroin solution (32%), mix and place in a slurry homogenizer for stirring, mix evenly, put into a dispensing syringe, degas in a centrifuge, and obtain a uniformly mixed printing slurry A; 2) Preparation of printing slurry for bioactive glass hydrogel composite material: Weigh 3g chitosan, add 150ml 2% acetic acid solution, stir to dissolve, add 13ml 0.4mol / L glutaraldehyde aqueous solution, stir and keep at 50℃ for 1h to obtain chitosan hydrogel. Then take 20g chitosan hydrogel (40%), 12g silk fibroin solution (24%) with a mass concentration of 6% and 18g bioactive glass (36%), mix them, and stir with a mechanical stirrer at a speed of 60r / min for 30min to fully mix the slurry to obtain a delicate and soft printing slurry B; 3) Preparation of hydrogel: Weigh 30 g of chitosan hydrogel (71%) and 12 g (29%) of silk fibroin solution with a mass concentration of 6%, stir evenly to obtain printing slurry C.
[0042] (3) 3D printing: The STL format file established for the cartilage defect model in (1) above is loaded into a multi-nozzle extrusion bioceramic 3D printing device, and then three barrels filled with different printing slurries are installed on the print head, and the above-treated printing slurry is used for 3D printing. During the printing process, the subchondral bone layer structure is first printed, using slurry A for printing, with a porosity of 30%~50% gradient structure, and then the cartilage transition layer is printed, using slurry B for printing, with a porosity of 50%~80% gradient structure, and finally the transparent cartilage layer is printed, using slurry C for printing, with a porosity greater than 80% gradient structure. At the junction, a dual-nozzle interactive printing method should be adopted to make the interface tightly connected to form a unified structure.
[0043] (4) Post-freeze drying and cleaning: The printed composite multilayer cartilage scaffold is placed in a freeze dryer for freeze drying. After freeze drying, the cartilage scaffold is placed in sterile injection water for ultrasonic cleaning for 1 hour, and then placed in a freeze dryer for freeze drying. This process is repeated once.
[0044] (5) Sterilization packaging: The composite multi-layer cartilage scaffold is sterilized by low-temperature sterilization and then packaged.
[0045] Implementation Case 3: (1) Obtaining a solid model of bone defect: Use medical imaging technology to obtain the cross-sectional DICOM data of the patient's cartilage defect site, and reconstruct the data in three dimensions. Combined with the patient's cartilage defect site and individual characteristics, a morphologically matching cartilage defect model is designed. The model is designed with different pore structures and saved as an STL format file.
[0046] (2) Raw material preparation: 1) Preparation of bioactive glass printing slurry: a certain amount of collagen was dissolved in an acetic acid solution to prepare a collagen solution with a mass concentration of 40%, and 37 g of bioactive glass (67%) was then added to 18 g of the collagen solution (33%). The mixture was placed in a slurry homogenizer for stirring. After the mixture was evenly mixed, it was loaded into a barrel and degassed in a centrifuge to obtain a uniformly mixed printing slurry A. 2) Preparation of printing slurry of bioactive glass and hydrogel composite material: 20g of bioactive glass (40%), 18g of 4% sodium alginate aqueous solution (36%) and 12g of 8% polyvinyl alcohol (24%) aqueous solution were mixed, and then mechanically stirred at a speed of 60r / min for 30min to fully mix the slurry to obtain a delicate and soft printing slurry B; 3) Preparation of hydrogel: 42g of 4% sodium alginate aqueous solution (84%) was mixed with 8g of 8% polyvinyl alcohol aqueous solution (16%), and then mechanically stirred at a speed of 60r / min for 30min to fully mix the slurry to obtain a delicate and soft printing slurry C; (3) 3D printing: The STL format file established for the cartilage defect model in (1) above is loaded into a multi-nozzle extrusion bioceramic 3D printing device, and then three barrels filled with different printing slurries are installed on the print head, and 3D printing is performed using the above-treated printing slurry. During the printing process, the subchondral bone layer structure is first printed, using slurry A for printing, with a porosity of 30%~50% gradient structure, and then the cartilage transition layer is printed, using slurry B for printing, with a porosity of 50%~80% gradient structure, and finally the transparent cartilage layer is printed, using slurry C for printing, with a porosity greater than 80% gradient structure. At the junction, a dual-nozzle interactive printing method should be adopted to make the interface tightly connected to form a unified structure.
[0047] (4) Post-freeze drying and cleaning: The printed composite multilayer cartilage scaffold is placed in a freeze dryer for freeze drying. After freeze drying, the cartilage scaffold is placed in sterile injection water for ultrasonic cleaning for 1 hour, and then placed in a freeze dryer for freeze drying. This process is repeated once.
[0048] (5) Sterilization packaging: The composite multi-layer cartilage scaffold is sterilized by low-temperature sterilization and then packaged.
[0049] Implementation Case 4 (1) Obtaining a solid model of bone defect: Use medical imaging technology to obtain the cross-sectional DICOM data of the patient's cartilage defect site, and reconstruct the data in three dimensions. Combined with the patient's cartilage defect site and individual characteristics, a morphologically matching cartilage defect model is designed. The model is designed with different pore structures and saved as an STL format file.
[0050] (2) Raw material preparation: 1) Preparation of bioactive glass printing slurry: 38 g of bioactive glass (79%) and 10 g of 8% polyvinyl alcohol aqueous solution (21%) were mixed, and the mixture was placed in a slurry homogenizer for stirring. After the mixture was evenly mixed, it was loaded into a dispensing syringe and degassed in a centrifuge to obtain a uniformly mixed printing slurry A; 2) Preparation of bioactive glass and hydrogel composite printing slurry: 38g of bioactive glass (54%), 10g of 4% sodium alginate aqueous solution, 12g of 5% gelatin aqueous solution (32% by mass of hydrogel), and 10g of 8% polyvinyl alcohol aqueous solution (14%) were mixed, and then mechanically stirred at a speed of 60r / min for 30min to fully mix the slurry to obtain a delicate and soft printing slurry B; 3) Preparation of hydrogel: 12g of 4% sodium alginate aqueous solution, 22g of 5% gelatin aqueous solution (hydrogel mass ratio is 81%), and 8g of 8% polyvinyl alcohol aqueous solution (19%) were mixed, and then mechanically stirred at a speed of 60r / min for 30min to fully mix the slurry to obtain a delicate and soft printing slurry C; (3) 3D printing: The STL format file established for the cartilage defect model in (1) above is loaded into a multi-nozzle extrusion bioceramic 3D printing device, and then three barrels filled with different printing slurries are installed on the print head, and 3D printing is performed using the above-treated printing slurry. During the printing process, the subchondral bone layer structure is first printed, using slurry A for printing, with a porosity of 30%~50% gradient structure, and then the cartilage transition layer is printed, using slurry B for printing, with a porosity of 50%~80% gradient structure, and finally the transparent cartilage layer is printed, using slurry C for printing, with a porosity greater than 80% gradient structure. At the junction, a dual-nozzle interactive printing method should be adopted to make the interface tightly connected to form a unified structure.
[0051] (4) Post-freeze drying and cleaning: The printed composite multilayer cartilage scaffold is placed in a freeze dryer for freeze drying. After freeze drying, the cartilage scaffold is placed in sterile injection water for ultrasonic cleaning for 1 hour, and then placed in a freeze dryer for freeze drying. This process is repeated once.
[0052] (5) Sterilization packaging: The composite multi-layer cartilage scaffold is sterilized by low-temperature sterilization and then packaged.
[0053] Implementation Case 5 In this embodiment, compared with Example 1, the amount of bioactive glass added in printing slurry A is 43g (86%), and the amount of polyvinyl alcohol aqueous solution added is 7g (14%); in printing slurry B, the amount of bioactive glass added is 19g (30%), the amount of bacterial cellulose added is 35g (55%), and the amount of polylactic acid added is 10g (15%). In printing slurry C, the amount of polylactic acid added is 17g (10%), and the amount of bacterial cellulose added is 50g (90%).
[0054] The remaining parts not involved are the same as those in Example 1.
[0055] Implementation Case 6 In this embodiment, compared with Example 1, the amount of bioactive glass added in printing slurry A is 32.5 g (65%), and the amount of polyvinyl alcohol aqueous solution added is 17.5 g (35%); in printing slurry B, the amount of bioactive glass added is 35 g (55%), the amount of bacterial cellulose added is 19 g (30%), and the amount of polylactic acid added is 10 g (15%). In printing slurry C, the amount of polylactic acid added is 27 g (40%), and the amount of bacterial cellulose added is 40 g (60%).
[0056] The remaining parts not involved are the same as those in Example 1.
[0057] Implementation Case 7 Compared with Example 1, in this example, the amount of bioactive glass added to the printing slurry B is 29 g (45%), the amount of bacterial cellulose added is 29 g (45%), and the amount of polylactic acid added is 6 g (10%).
[0058] The remaining parts not involved are the same as those in Example 1.
[0059] Implementation Case 8 Compared with Example 1, in this example, the amount of bioactive glass added to the printing slurry B is 26 g (40%), the amount of bacterial cellulose added is 22 g (35%), and the amount of polylactic acid added is 16 g (25%).
[0060] The remaining parts not involved are the same as those in Example 1.
[0061] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.
Claims
1. A bioactive glass-based composite multi-layer cartilage scaffold, characterized in that: It includes a subchondral bone layer, a cartilage transition layer and a hyaline cartilage layer stacked in sequence from bottom to top; the subchondral bone layer is composed of bioactive glass and a binder, the cartilage transition layer is composed of bioactive glass, hydrogel and a binder; the hyaline cartilage layer is composed of hydrogel and a binder.
2. The bioactive glass-based composite multi-layer cartilage scaffold according to claim 1, characterized in that: The porosity of the subchondral bone layer is 30% to 50%, the porosity of the cartilage transition layer is 50% to 80%, and the porosity of the hyaline cartilage layer is greater than 80%.
3. The bioactive glass-based composite multi-layer cartilage scaffold according to claim 1, characterized in that: In terms of mass fraction, the bioactive glass in the subchondral bone layer accounts for 65wt% to 86wt%, and the adhesive accounts for 14% to 35%.
4. The bioactive glass-based composite multi-layer cartilage scaffold according to claim 1, characterized in that: In terms of mass fraction, the bioactive glass and the hydrogel in the cartilage transition layer each account for 30wt% to 55wt%, and the binder accounts for 10% to 25%.
5. The bioactive glass-based composite multi-layer cartilage scaffold according to claim 1, characterized in that: In terms of mass fraction, the hydrogel in the hyaline cartilage layer accounts for 60 wt % to 90 wt %, and the binder accounts for 10% to 40%.
6. The bioactive glass-based composite multi-layer cartilage scaffold according to claim 1, characterized in that: The bioactive glass includes SiO2, Na2O, CaO and P2O5.
7. The bioactive glass-based composite multi-layer cartilage scaffold according to claim 1, characterized in that: The hydrogel material is one or more of bacterial cellulose, sodium alginate, gelatin and chitosan.
8. The bioactive glass-based composite multi-layer cartilage scaffold according to claim 1, characterized in that: The bonding aid is one or more of polylactic acid, polyvinyl alcohol, silk fibroin and collagen.
9. A method for preparing the bioactive glass-based composite multi-layer cartilage scaffold according to claim 1, characterized in that: The following steps are involved: Obtaining a cartilage defect model; obtaining the tomographic data of the cartilage defect site of the patient through medical imaging, performing three-dimensional reconstruction through the tomographic data, and designing a model, wherein pores are set in the model, and saving the model in an STL format file; Prepare slurries; prepare printing slurry A, printing slurry B and printing slurry C respectively; the printing slurry A is composed of bioactive glass and a binder; the printing slurry B is composed of bioactive glass, hydrogel and a binder; the printing slurry C is composed of a hydrogel and a binder; 3D printing, loading the STL format file into a multi-nozzle extrusion bioceramic 3D printing device, installing three barrels respectively filled with printing slurry A, printing slurry B and printing slurry C on the printing head for printing; first printing the subchondral bone layer, then printing the cartilage transition layer, and finally printing the transparent cartilage layer; obtaining a cartilage scaffold blank; Post-processing: freeze-drying the cartilage scaffold blank and then cleaning it, sterilizing the cleaned cartilage scaffold blank, and finally obtaining a bioactive glass-based composite multilayer cartilage scaffold.
10. The method for preparing the bioactive glass-based composite multi-layer cartilage scaffold according to claim 9, characterized in that: During the 3D printing process, dual nozzle interactive printing was used when printing the junction of the subchondral bone layer and the cartilage transition layer, as well as the junction of the cartilage transition layer and the hyaline cartilage layer.