Preparation method of gradient bionic rotator cuff repair stent, stent prepared by method and application

Abstract

The invention provides a preparation method of a gradient bionic rotator cuff repair stent, the stent prepared by the method and application. The method comprises the following steps that 1, a gradient fiber structure is designed through conventional 3D modeling software; step 2, adding the raw materials into the barrel material, and printing a tendon scaffold by adopting a near-field direct-writing melting technology; 3, raw materials in the barrel material are replaced, and the cartilage scaffold is printed through the near-field direct-writing melting technology; optionally, replacing the raw materials in the barrel material, and printing the mineralized cartilage scaffold by adopting a near-field direct-writing melting technology; and 4, replacing the raw materials in the barrel material, and printing the bone scaffold by adopting a near-field direct-writing fusion technology. The stent disclosed by the invention has a structural gradient and a component gradient, is matched with natural bone tissues, and can better promote the repair of the bone tissues.

Description

Technical Field

[0001] The present invention relates to the technical field of biomaterials, and more particularly to a method for preparing a gradient bionic rotator cuff repair stent, and the stent prepared by the method and its application. Background Art

[0002] Connective tissues such as tendons or ligaments are attached to bones through multi-tissue interfaces, and their composition, structure, and mechanical properties have spatial gradients. These gradients minimize stress concentration and mediate load transfer between soft and hard tissues. The rotator cuff is mainly composed of four parts: tendon, cartilage, mineralized fibrocartilage, and bone. In the transition from tendon to bone, the mineral content inside the tissue is gradually increasing; at the structural level, the structure inside the tissue is becoming more and more dense. Therefore, the repair scaffold material also needs a gradual gradient of porosity.

[0003] At present, most scaffold materials are composed of a single-layer structure or a two-layer structure, without fully considering the bionic structure of the natural rotator cuff. Therefore, most of the healing effects are only the massive proliferation of fibroblasts in the tissue, which eventually gradually forms scars, which will largely cause re-tear and cannot achieve true regional repair of the rotator cuff area. Therefore, it is of great significance to construct a scaffold with a bionic structure.

[0004] In recent years, due to the good biocompatibility, biodegradability, high surface / volume ratio and the characteristics of mimicking the hierarchical structure of the extracellular matrix (ECM) of the nanofiber membrane prepared by electrospinning technology, the electrospun nanofiber membrane is very suitable as a scaffold for tissue engineering applications. A variety of materials such as polycaprolactone (PCL), polylactic acid (PLLA), polylactic-co-glycolic acid (PLGA), collagen and gelatin have been developed for electrospinning to make fiber membranes. However, the scaffolds prepared by traditional electrospinning technology are relatively thin, which is not conducive to tissue repair in areas with deep size defects, such as skulls and large-sized rotator cuff tears. Near-field direct writing electrospinning technology is a technology that combines electrospinning and 3D printing. Under the interaction of multiple forces such as electric field force, electrostatic force, gravity and traction, a scaffold with controllable structure and fiber diameter of up to ten or even several microns is accurately prepared. Thinner fiber diameter is more conducive to cell adhesion and proliferation. When using near-field direct writing technology to prepare scaffolds, the raw materials also have certain requirements and limitations. For example, polylactic acid (PLLA) has the disadvantages of high printing temperature and slow degradation rate; polylactic acid-glycolic acid copolymer (PLGA) degrades quickly but has high viscosity and brittleness; polycaprolactone (PCL) has good biocompatibility, biodegradability, toughness and processability, but its hydrophilicity is poor. In addition, the fiber membrane prepared from pure polymer materials has insufficient biological activity and is generally used in combination with other active nanomaterials (such as hydroxyapatite, β-tricalcium phosphate, etc.) to enhance osteogenic performance or biomechanical strength. Active nanomaterials can be adsorbed on polymer scaffolds by surface modification or physical modification, but the disadvantage of this modification method is that it is easy to cause the sudden release of active nanomaterials and cannot achieve a sustained release effect in local areas, thus affecting the repair effect.

[0005] Therefore, it is an urgent problem to research and develop a low-cost, biocompatible, sustained drug release, and tissue engineering bionic scaffold that can induce stem cell differentiation to assist in the repair of rotator cuff injuries. Summary of the invention

[0006] To solve the above problems, the present invention provides a method for preparing a gradient bionic rotator cuff repair scaffold. The scaffold prepared by the present invention has a structural gradient and a bioactive concentration gradient, matches the natural rotator cuff tissue, and can better promote the repair of the rotator cuff injury area.

[0007] First of all, one of the purposes of the present invention is to provide a method for preparing a gradient bionic rotator cuff repair scaffold.

[0008] Specifically, the preparation method of the stent comprises the following steps:

[0009] Step 1: Design the gradient fiber structure using EFL-Potato E or other conventional 3D modeling software;

[0010] Step 2: Add the raw materials to the drum, and use near-field direct writing melting technology (i.e., near-field melt electrospinning technology) to print the tendon scaffold;

[0011] Step 3: Replace the raw materials in the barrel and use near-field direct writing melting technology to print the cartilage scaffold;

[0012] Optionally, the raw material in the barrel is replaced, and the mineralized cartilage scaffold is printed by near-field direct writing melting technology;

[0013] Step 4: Replace the raw material in the barrel and use near-field direct writing melting technology to print the bone scaffold.

[0014] Preferably, the raw material for preparing the tendon scaffold is a high molecular polymer.

[0015] Preferably, the raw materials for preparing the cartilage scaffold, mineralized cartilage scaffold and bone scaffold are a mixture of high molecular polymer and active nanomaterial.

[0016] Preferably, the high molecular polymer is one or a combination of polycaprolactone, polylactic acid, polylactic acid-glycolic acid, and polyurethane; and the active nanomaterial is one or a combination of hydroxyapatite, calcium peroxide, and black phosphorus nanosheets.

[0017] Preferably, in the cartilage scaffold, the mass of the active nanomaterial is 1-20% of the mass of the high molecular weight polymer; more preferably, 1-10%.

[0018] Preferably, in the mineralized cartilage scaffold, the mass of the active nanomaterial is 1 to 30% of the mass of the high molecular weight polymer; preferably 11 to 20%.

[0019] Preferably, in the bone scaffold, the mass of the active nanomaterial is 1 to 60% of the mass of the high molecular weight polymer; preferably 21 to 30%.

[0020] Secondly, the second object of the present invention is to provide a stent prepared by the preparation method of one of the objects of the present invention.

[0021] Specifically, the scaffold provided by the present invention is a scaffold with a structural gradient and a bioactive concentration gradient obtained by printing a high molecular polymer and an active nanomaterial through a near-field direct writing melting technology (i.e., a near-field melt electrospinning technology). It is worth mentioning that the gradient fiber structure of the present invention is composed of a plurality of fiber membrane layers, and the fiber membrane layer is composed of a plurality of fibers that are arranged in an orderly manner in a longitudinal, transverse, or longitudinal and transverse direction. The present invention can controllably adjust the diameter, arrangement, and spacing of the fibers in the scaffold according to the structure designed by the software to obtain a scaffold with a practical structural gradient.

[0022] Preferably, the diameter of the fibers in the scaffold is 1 to 200 μm; and the spacing between the fibers in the scaffold is 0.1 to 1 mm.

[0023] Preferably, the scaffolds of the present invention include tendon scaffolds, cartilage scaffolds, mineralized cartilage scaffolds and bone scaffolds.

[0024] Preferably, the tendon scaffold consists of 1 to 30 layers, preferably 20 to 30 layers of fiber membrane layers; the cartilage scaffold consists of 5 to 30 layers, preferably 5 to 15 layers of fiber membrane layers; the mineralized cartilage scaffold consists of 5 to 15 layers of fiber membrane layers; the bone scaffold consists of 10 to 30 layers, preferably 20 to 30 layers of fiber membrane layers.

[0025] Again, the third object of the present invention is to provide the application of the gradient bionic rotator cuff repair stent of the second object of the present invention.

[0026] Specifically, the scaffold of the present invention has a structural gradient and a component gradient, which matches natural bone tissue, and can be used for promoting osteogenesis, cartilage formation, and repair of tendon injuries in the rotator cuff.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] 1. The near-field direct writing technology (i.e., near-field melt electrospinning technology) adopted by the present invention prints electrospun micro-nano fibers. Compared with the scaffold obtained by traditional electrospinning, the fiber diameter, arrangement, and spacing of the scaffold of the present invention are all controllable. Compared with the traditional 3D printing technology, the fiber diameter of the prepared scaffold is thinner. For example, the fiber diameter can be regulated by adjusting the distance between the print nozzle and the platform, as well as the printing voltage and air pressure; the fiber arrangement and spacing can be regulated by the 3D modeling software design code. The fiber diameter in the scaffold provided by the present invention is 1 to 200 μm, which is significantly smaller than the cell diameter, so that the cells can easily climb on it, and the fiber spacing is 100 to 1000 μm, which is convenient for bone and tendon growth. At the same time, the present invention can also flexibly adjust the fiber arrangement and spacing according to different inoculated cells and the required repair tissue.

[0029] 2. The repair stent of the present invention is designed according to the physiological structure of the rotator cuff junction. The stent of the present invention has a layered structure gradient and a component gradient. The content of active nanomaterials (such as hydroxyapatite) in the tendon forming part is low, while the content of active nanomaterials in the bone forming part is significantly increased. The structure and composition of the cartilage part in the middle are located between the two. At the same time, the dual-gradient stent ensures the slow and long-term release of active nanomaterials on the one hand, and meets the requirements of biological activity of different repair parts on the other hand, thereby achieving a better repair effect.

[0030] 3. The fiber diameter of the scaffold provided by the present invention is relatively thin, which is easy for stem cells to adhere and migrate. The bionic designed scaffold microstructure and microenvironment can make stem cells differentiate in different directions on different structures of the scaffold, ultimately achieving the effect of promoting the integrated repair of tendon and bone. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a schematic diagram of the near-field direct writing electrospinning printing platform of the present invention;

[0032] Figure 2 This is a scanning electron microscope image of the gradient scaffold prepared in Example 1;

[0033] Figure 3 This is a statistical diagram of the diameter distribution of the stent prepared in Example 1;

[0034] Figure 4 This is a semi-quantitative statistical graph of the tendon-related protein SCX of the cell differentiation immunofluorescence of the scaffold prepared in Example 1;

[0035] Figure 5 This is a semi-quantitative statistical graph of the chondrogenesis-related protein COLⅡ of the cell differentiation immunofluorescence of the scaffold prepared in Example 1;

[0036] Figure 6 This is a semi-quantitative statistical graph of the osteogenic-related protein ALP of the cell differentiation immunofluorescence of the scaffold prepared in Example 1. DETAILED DESCRIPTION

[0037] The present invention is described in detail below in conjunction with specific drawings and embodiments. It is necessary to point out that the following embodiments are only used to further illustrate the present invention and cannot be understood as limiting the scope of protection of the present invention. Some non-essential improvements and adjustments made to the present invention by those skilled in the art based on the content of the present invention still fall within the scope of protection of the present invention.

[0038] In the following examples and comparative examples, the raw materials are all derived from commercially available products.

[0039] Example 1

[0040] This example is used to illustrate the preparation of a gradient bionic rotator cuff repair scaffold. A multilayer electrospun nanofiber scaffold with a structural gradient and a component gradient is printed using near-field melt direct writing technology (i.e., near-field melt electrospinning technology). The specific steps are as follows:

[0041] Step 1: Design a grid structure using EFL-Potato E software;

[0042] Step 2: Add polycaprolactone (PCL) raw material to the cylinder, and 30 layers of PCL tendon scaffolds with a spacing of 0.18×0.18mm are printed at the bottom by 3D printing;

[0043] Step 3: Add polycaprolactone raw material containing 10% hydroxyapatite (10% HAP-PCL) to the barrel, and continue to print 10 layers of 10% HAP-PCL cartilage scaffolds with a spacing of 0.18×0.18 mm on the tendon layer in step 2;

[0044] Step 4: Add a polycaprolactone raw material containing 20% ​​hydroxyapatite (20% HAP-PCL) to the barrel, and continue to print 15 layers of 20% HAP-PCL mineralized cartilage scaffolds with a spacing of 0.36×0.36 mm on the cartilage layer in step 3;

[0045] Step 5: Add polycaprolactone raw material (30% HAP-PCL) containing 30% hydroxyapatite to the barrel, and continue to print 30 layers of 30% HAP-PCL bone scaffolds with a spacing of 0.36×0.36mm on the mineralized fibrous cartilage layer of step 4; finally, a repair scaffold with integrated structure and composition gradient is obtained.

[0046] Figure 1 A diagram of the near-field melt direct writing electrospinning printing platform used to prepare the stent of this example is shown.

[0047] Figure 2 and Figure 3 The electron microscope scanning image and diameter distribution statistical graph of the gradient scaffold prepared in this example are shown.

[0048] Figures 4 to 6 Figure 2 shows the cell differentiation statistics of the gradient scaffold prepared by this example. Figures 4 to 6 It can be seen that in the cell differentiation experiment, the above scaffolds were used for cell differentiation experiments, and the cells were cultured on different scaffolds and added with osteogenic, chondrogenic and tendogenic differentiation fluids. After 21 days of differentiation, they were stained with osteogenic-related protein ALP, chondrogenic-related protein COLⅡ and tendogenic-related protein SCX. The semi-quantitative statistics of the confocal results showed that the corresponding protein expression levels of the corresponding scaffolds were higher, indicating successful differentiation. Specifically, by Figure 4 It can be seen that 0.18*0.18-Te means that the tendon scaffold with a spacing of 0.18*0.18mm has the highest expression of the tendon-related protein SCX, indicating that it is most conducive to promoting tendon repair; Figure 5 It can be seen that 0.18*0.36-Tr represents the cartilage repair layer in the middle transition area composed of the cartilage scaffold with a spacing of 0.18mm*0.18mm and the mineralized cartilage scaffold with a spacing of 0.36*0.36mm. The expression of the cartilage-related protein COLⅡ is the highest, indicating that it is most conducive to promoting cartilage repair. Figure 6 It can be seen that 0.36*0.36-B represents the bone scaffold with a spacing of 0.36*0.36, which has the highest expression of osteogenesis-related protein ALP and is mainly used for bone tissue repair and regeneration.

[0049] Example 2

[0050] This example is used to illustrate the preparation of a gradient bionic rotator cuff repair scaffold. A multilayer electrospun nanofiber scaffold with a structural gradient and a component gradient is printed using near-field melt direct writing technology (i.e., near-field melt electrospinning technology). The specific steps are as follows:

[0051] Step 1: Design a grid structure using EFL-Potato E software;

[0052] Step 2: Add polycaprolactone (PCL) raw material to the cylinder, and 3D print 20 layers of PCL tendon scaffolds with a spacing of 0.2*0.2mm at the bottom;

[0053] Step 3: Add polycaprolactone raw material containing 10% hydroxyapatite (10% HAP-PCL) to the barrel, and continue to print 10 layers of 10% HAP-PCL cartilage layer scaffolds with a spacing of 0.25*0.25mm on the tendon layer in step 2;

[0054] Step 4: Add polycaprolactone raw material (20% HAP-PCL) containing 20% ​​hydroxyapatite to the barrel, and continue to print 20 layers of 20% HAP-PCL bone layer scaffolds with a spacing of 0.30*0.30mm on the cartilage layer in step 3; finally, a repair scaffold with integrated structure and composition gradient is obtained.

[0055] Example 3

[0056] This example is used to illustrate the preparation of a gradient bionic rotator cuff repair scaffold. A multilayer electrospun nanofiber scaffold with a structural gradient and a component gradient is printed using near-field melt direct writing technology (i.e., near-field melt electrospinning technology). The specific steps are as follows:

[0057] Step 1: Design a grid structure using EFL-Potato E software;

[0058] Step 2: Add polycaprolactone (PCL) raw material to the cylinder, and 3D print 20 layers of PCL tendon scaffolds with a spacing of 0.18*0.18mm at the bottom;

[0059] Step 3: Add polycaprolactone raw material containing 10% hydroxyapatite (10% HAP-PCL) to the barrel, and continue to print 5 layers of 10% HAP-PCL cartilage layer scaffolds with a spacing of 0.24*0.24mm on the tendon layer in step 2;

[0060] Step 4: Add polycaprolactone raw material containing 20% ​​hydroxyapatite (20% HAP-PCL) to the barrel, and continue to print 5 layers of 20% HAP-PCL mineralized cartilage layer scaffolds with a spacing of 0.24*0.24mm on the cartilage layer in step 3;

[0061] Step 5: Add polycaprolactone raw material (30% HAP-PCL) containing 30% hydroxyapatite to the barrel, and continue to print 20 layers of 30% HAP-PCL bone layer scaffolds with a spacing of 0.36*0.36mm on the mineralized cartilage layer in step 4; finally, a repair scaffold with integrated structure and composition gradient is obtained.

[0062] Example 4

[0063] This example is used to illustrate the preparation of a gradient bionic rotator cuff repair scaffold. A multilayer electrospun nanofiber scaffold with a structural gradient and a component gradient is printed using near-field melt direct writing technology (i.e., near-field melt electrospinning technology). The specific steps are as follows:

[0064] Step 1: Design a grid structure using Rhino software;

[0065] Step 2: Add polycaprolactone (PCL) raw material to the cylinder, and 3D print 15 layers of PCL tendon scaffolds with a spacing of 0.18*0.18mm at the bottom;

[0066] Step 3: Add 2% hydroxyapatite-containing polycaprolactone raw material (2% HAP-PCL) to the barrel, and continue to print 15 layers of 2% HAP-PCL cartilage layer scaffolds with a spacing of 0.20*0.20mm on the tendon layer in step 2;

[0067] Step 4: Add polycaprolactone raw material containing 12% hydroxyapatite (12% HAP-PCL) to the barrel, and continue to print 10 layers of 12% HAP-PCL mineralized cartilage layer scaffolds with a spacing of 0.24*0.24mm on the cartilage layer in step 3;

[0068] Step 5: Add polycaprolactone raw material (21% HAP-PCL) containing 21% hydroxyapatite to the barrel, and continue to print 25 layers of 21% HAP-PCL bone layer scaffolds with a spacing of 0.36*0.36mm on the mineralized cartilage layer of step 4; finally, a repair scaffold with integrated structure and composition gradient is obtained.

[0069] Example 5

[0070] This example is used to illustrate the preparation of a gradient bionic rotator cuff repair scaffold. A multilayer electrospun nanofiber scaffold with a structural gradient and a component gradient is printed using near-field melt direct writing technology (i.e., near-field melt electrospinning technology). The specific steps are as follows:

[0071] Step 1: Design a grid structure using Autodesk 3ds Max software;

[0072] Step 2: Add polylactic acid-co-glycolic acid (PLGA) raw material into the cylinder, and 3D print 20 layers of PLGA tendon scaffolds with a spacing of 0.2×0.2 mm at the bottom;

[0073] Step 3: Add the raw material of polylactic acid-glycolic acid copolymer containing 10% black phosphorus (10% BP-PLGA) to the barrel, and continue to print 20 layers of 10% BP-PLGA cartilage layer scaffolds with a spacing of 0.3×0.3 mm on the tendon layer in step 2;

[0074] Step 4: Add polylactic acid-glycolic acid copolymer (20% BP-PLGA) containing 20% ​​BP to the barrel, and continue to print 30 layers of 20% BP-PLGA bone layer scaffolds with a spacing of 0.40×0.40mm on the cartilage layer in step 3; finally, a repair scaffold with integrated structure and composition gradient is obtained.

[0075] Example 6

[0076] This example is used to illustrate the preparation of a gradient bionic rotator cuff repair scaffold. A multilayer electrospun nanofiber scaffold with a structural gradient and a component gradient is printed using near-field melt direct writing technology. The specific steps are as follows:

[0077] Step 1: Design a grid structure using Blender software;

[0078] Step 2: Add polylactic acid (PLA) raw material to the barrel, and 3D print 5 layers of PLA tendon scaffolds with a spacing of 0.1×0.1mm at the bottom;

[0079] Step 3: Add polylactic acid raw material (5% CaO2-PLA) containing 5% calcium peroxide (CaO2) to the barrel, and continue to print 25 layers of 5% CaO2-PLA cartilage layer scaffolds with a spacing of 0.3×0.3 mm on the tendon layer in step 2;

[0080] Step 4: Add polylactic acid raw material (10% CaO2-PLA) containing 10% calcium peroxide to the barrel, and continue to print 5 layers of 10% CaO2-PLA mineralized cartilage layer scaffolds with a spacing of 0.5×0.5 mm on the cartilage layer in step 3;

[0081] Step 5: Add polylactic acid raw material (20% CaO2-PLA) containing 20% ​​calcium peroxide to the barrel, and continue to print 30 layers of 20% CaO2-PLA bone layer scaffolds with a spacing of 0.7×0.7mm on the mineralized cartilage layer in step 4; finally, a repair scaffold with integrated structure and composition gradient is obtained.

[0082] Example 7

[0083] This example is used to illustrate the preparation of a gradient bionic rotator cuff repair scaffold. A multilayer electrospun nanofiber scaffold with a structural gradient and a component gradient is printed using near-field melt direct writing technology (i.e., near-field melt electrospinning technology). The specific steps are as follows:

[0084] Step 1: Design a grid structure using Shapr3D software;

[0085] Step 2: Add polyurethane (PU) raw materials to the barrel, and 3D print 15 layers of PU tendon scaffolds with a spacing of 0.18×0.18mm at the bottom;

[0086] Step 3, add a polyurethane raw material containing 2% hydroxyapatite (2% HAP-PU) to the barrel, and continue to print 15 layers of 2% HAP-PU cartilage layer scaffolds with a spacing of 0.20×0.20 mm on the tendon layer in step 2;

[0087] Step 4: Add a polyurethane raw material containing 12% hydroxyapatite (12% HAP-PU) to the barrel, and continue to print 10 layers of 12% HAP-PU mineralized cartilage layer scaffolds with a spacing of 0.24×0.24 mm on the cartilage layer in step 3;

[0088] Step 5: Add a polyurethane raw material containing 21% hydroxyapatite (21% HAP-PU) to the barrel, and continue to print 25 layers of 21% HAP-PU bone layer scaffolds with a spacing of 0.36×0.36mm on the mineralized cartilage layer of step 4; finally, a repair scaffold with integrated structure and composition gradient is obtained.

[0089] The preferred embodiments of the present invention are described in detail above, but the present invention is not limited thereto. Within the technical concept of the present invention, the technical solution of the present invention can be subjected to a variety of simple modifications, including the combination of various technical features in any other suitable manner, and these simple modifications and combinations should also be regarded as the contents disclosed by the present invention and belong to the protection scope of the present invention.

Claims

1. A method for preparing a gradient bionic rotator cuff repair scaffold, characterized in that: The method comprises the following steps: Step 1: Design the gradient fiber structure using EFL--Potato E software; Step 2: Add the raw materials into the barrel and use the near-field direct writing melting technology to print the tendon scaffold; Step 3: Replace the raw materials in the barrel and use near-field direct writing melting technology to print the cartilage scaffold; Optionally, the raw material in the barrel is replaced, and the mineralized cartilage scaffold is printed by near-field direct writing melting technology; Step 4: Replace the raw material in the barrel and use near-field direct writing melting technology to print the bone scaffold.

2. The method for preparing the gradient bionic rotator cuff repair scaffold according to claim 1, characterized in that: The raw material for preparing the tendon scaffold is a high molecular polymer; the raw materials for preparing the cartilage scaffold, mineralized cartilage scaffold and bone scaffold are a composite of a high molecular polymer and active nanomaterials.

3. The method for preparing the gradient bionic rotator cuff repair scaffold according to claim 2, characterized in that: The high molecular polymer is one or a combination of polycaprolactone, polylactic acid, polylactic acid-glycolic acid copolymer, and polyurethane; and / or the active nanomaterial is one or a combination of hydroxyapatite, calcium peroxide, and black phosphorus nanosheets.

4. The method for preparing the gradient bionic rotator cuff repair scaffold according to claim 2, characterized in that: In the cartilage scaffold, the mass of the active nanomaterial is 1 to 20% of the mass of the high molecular weight polymer; preferably 1 to 10%; and / or, In the mineralized cartilage scaffold, the mass of the active nanomaterial is 1 to 30% of the mass of the high molecular weight polymer; preferably 11 to 20%; and / or, In the bone scaffold, the mass of the active nanomaterial is 1 to 60% of the mass of the high molecular polymer, preferably 21 to 30%.

5. A gradient bionic rotator cuff repair stent, characterized in that: The stent is prepared by the preparation method according to any one of claims 1 to 4.

6. The gradient bionic rotator cuff repair stent according to claim 5, characterized in that: The scaffold has a gradient fiber structure.

7. The gradient bionic rotator cuff repair stent according to claim 6, characterized in that: The gradient fiber structure is composed of a plurality of fiber membrane layers, and the fiber membrane layers are composed of a plurality of fibers which are arranged in an orderly manner in a longitudinal direction, a transverse direction, or a longitudinal direction and a transverse direction.

8. The gradient bionic rotator cuff repair stent according to claim 6, characterized in that: The diameter of the fiber in the scaffold is 1 to 200 μm; and / or, The spacing between the fibers in the support is 0.1 to 1 mm.

9. The gradient bionic rotator cuff repair stent according to claim 6, characterized in that: The tendon scaffold contains 1 to 30 layers of fiber membrane; The cartilage scaffold contains 5 to 30 layers of fiber membrane; The mineralized cartilage scaffold contains 5 to 15 fiber membrane layers; The bone scaffold contains 10 to 30 fiber membrane layers.

10. The use of the gradient bionic rotator cuff repair stent according to any one of claims 5 to 9, characterized in that: The scaffold is used to promote tissue repair; preferably used to promote osteogenesis, cartilage formation, and repair of tendon injuries in the rotator cuff.

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