Rotator cuff patch containing exosomes and preparation method thereof

Abstract

The present invention discloses a rotator cuff patch containing exosomes and a preparation method thereof. Nanofibers are prepared by coaxial electrospinning, which mimics the ultrastructure of the extracellular matrix. At the same time, the nanofiber structure is similar to rotator cuff tissue and can mimic rotator cuff tissue. Moreover, the nanofibers have sufficient mechanical strength and elasticity to guide tissue growth in the appropriate direction and have ideal biomedical functions. The core layer contains exosomes, which can promote the migration and fusion of osteoblasts and tendon cells, and has the effect of promoting tissue healing. At the same time, because the exosomes are encapsulated in the nanofiber core layer structure, they are released more slowly than ordinary blended nanofibers. Therefore, the core-shell structure can slow down the release of exosomes and avoid sudden release. The present invention combines the complementary advantages of high molecular polymers, extracellular vesicles (exosomes), and natural collagen in terms of composition and properties, and combines the biomimetic structure of nanofibers to prepare a biomimetic rotator cuff patch with a rotator cuff structure and promoted healing.

Description

Technical Field

[0001] The present invention belongs to the technical field of bone tissue material preparation, and particularly relates to a rotator cuff patch containing exosomes and a preparation method thereof. Background Art

[0002] The rotator cuff is a cuff-like structure formed by the tendons of the supraspinatus, infraspinatus, teres minor, and subscapularis muscles, which wrap around the humeral head. These tendons stabilize the humeral head on the glenoid fossa, play a crucial role in shoulder joint stability, and maintain shoulder mobility. Damage to the rotator cuff can cause shoulder pain and dysfunction. Rotator cuff tears are one of the most common shoulder disorders, with a tear rate of 34% in the general population and as high as 54% in those over 60 years old. Despite improvements in surgical instruments and techniques, large rotator cuff tears remain a challenge for orthopedic surgeons. The current surgical treatment strategy is to repair the torn rotator cuff tendon. However, the literature reports re-rupture rates of 11% to 94% after repair. Although current clinical treatments, such as arthroscopic surgery, can improve patient outcomes by reducing pain and improving shoulder function, the recurrent defect (re-tear) rate remains unsatisfactory (21% at 1-2 years of follow-up). The rotator cuff tendons play a crucial role in shoulder biomechanics and are susceptible to injury and degenerative changes due to their location and blood supply. Even with tendon-bone attachment, the high tension on the repaired construct increases the risk of re-tear. Therefore, grafts have been developed to bridge large rotator cuff tears. However, limited healing potential between the tendon and graft, or between the graft and bone, remains a concern.

[0003] Electrospun nanofibers have a wide range of applications in tissue engineering, wound repair, drug delivery, neural probes, and orthopedic implants. These nanofibers contain nanofibers with varying orientations, mimicking the ultrastructure of the extracellular matrix (ECM), particularly in tissues with complex regions, such as the tendon-osteoendosteal junction. The organization and alignment of the nanofibers can be regulated during the fabrication process, enabling the scaffold's structure and material properties to meet the functional requirements of the rotator cuff tendon. Aligned scaffolds can mimic the parallel ECM of the native cellular microenvironment, enhancing matrix deposition and serving as three-dimensional micropatterns for neotissue formation. Non-aligned scaffolds or randomly oriented fibers have demonstrated promising results in osteogenesis and chondrogenesis. Among various electrospun polymers, polycaprolactone (PCL) has been approved by the US Food and Drug Administration as a component of biomaterial scaffolds due to its tunable biodegradability. Collagen I (Col I), a major component of the tendon ECM, promotes cell growth, migration, and differentiation through interactions with growth factors and enhances the polymer's cytocompatibility.

[0004] Exosomes are nanometer-sized (30-150 nm in diameter) extracellular vesicles naturally secreted by various cell types, including endothelial cells, immune cells, and mesenchymal stem cells (MSCs) derived from diverse sources such as bone marrow, adipose tissue, and human umbilical cord. The most attractive feature of exosomes is that they are cell-free, making them less complex from a regulatory perspective, and clinical trials are underway following emergency use authorization from the US Food and Drug Administration (FDA). The lipid bilayer structure of exosomes enables the transfer of information encoded in proteins, lipids, mRNA, miRNA, and metabolites, thereby facilitating intracellular communication. Compared to MSCs, MSC-derived exosomes exhibit similar biological activities, such as anti-inflammatory, pro-regenerative, and anti-apoptotic effects. Therefore, the therapeutic effects and mechanisms of exosomes in tissue healing have attracted increasing interest in enhancing rotator cuff repair.

[0005] However, currently clinically approved and commercially available rotator cuff patches, such as X-Repair, LARS ligament, and Poly-Tape, fail to fully approximate the macro- and micromechanical properties of the human supraspinatus tendon, exhibiting insufficient mechanical properties. Furthermore, newer rotator cuff patch materials, such as bioscaffolds and platelet-rich matrix, present biocompatibility issues. Unprocessed human tissue grafts can cause secondary damage to the body and may contain tissues such as fat, making tendon growth difficult. Summary of the Invention

[0006] In order to overcome the shortcomings of the above-mentioned prior art, the purpose of the present invention is to provide a rotator cuff patch containing exosomes and a preparation method thereof, which can effectively solve the technical problems of insufficient mechanical properties, biocompatibility and low biosafety of the existing rotator cuff patch.

[0007] In order to achieve the above object, the present invention adopts the following technical solutions:

[0008] The present invention discloses a rotator cuff patch containing exosomes, which is a core-shell nanofiber membrane structure; wherein the core layer is made of exosomes and a high molecular polymer, and the shell layer is made of a high molecular polymer;

[0009] The raw materials for preparing the exosome-containing rotator cuff patch include, by mass percentage:

[0010] In the nuclear layer: polymers are 1% to 15%, exosomes are 1% to 20%, and phosphate buffer is 65% to 92%;

[0011] In the shell layer: the high molecular polymer accounts for 5% to 30% and the hexafluoroisopropanol accounts for 70% to 95%.

[0012] Preferably, the high molecular polymer in the core layer is gelatin or polyvinyl alcohol; the high molecular polymer in the shell layer is polycaprolactone, polylactic acid-glycolic acid or a mixture of polylactic acid-glycolic acid and collagen.

[0013] Further preferably, the viscosity of polyvinyl alcohol is 30 to 220 mPa.s; the number average molecular weight of polycaprolactone is 10,000 to 100,000; the viscosity of polylactic acid-glycolic acid is 0.5 to 3 dL / g; and the mass ratio of polylactic acid-glycolic acid to collagen in the mixture of polylactic acid-glycolic acid and collagen is (5-9): (5-1).

[0014] More preferably, the collagen is type I collagen.

[0015] Preferably, the exosomes are derived from cells or body fluids, and the cells include stem cells, macrophages, endothelial cells or epithelial cells.

[0016] The present invention also discloses a method for preparing the above-mentioned rotator cuff patch containing exosomes, comprising the following steps:

[0017] 1) dissolving the high molecular weight polymer for preparing the shell layer in hexafluoroisopropanol and mixing thoroughly to obtain a shell layer spinning solution;

[0018] 2) Adding the polymer for preparing the core layer to a phosphate buffer solution, heating and stirring for 5 to 10 hours, and then adding exosomes after the temperature returns to room temperature to prepare a core layer spinning solution;

[0019] 3) The shell layer spinning solution and the core layer spinning solution are coaxially electrospun and sprayed onto an aluminum foil substrate to produce a rotator cuff patch containing exosomes.

[0020] Preferably, in step 1), the thorough mixing is performed by magnetic stirring at room temperature for 5 to 10 hours.

[0021] Preferably, in step 2), when the high molecular polymer is polyvinyl alcohol, the heating temperature is 80-100° C.; when the high molecular polymer is gelatin, the heating temperature is 37° C.

[0022] Preferably, in step 2), the pH value of the phosphate buffer is 7.4.

[0023] Preferably, in step 3), the operating parameters of the coaxial electrospinning process are: the propulsion rate of the shell spinning solution is 1 to 2 mL / h, the propulsion rate of the core spinning solution is 0.5 to 1 mL / h, the drum speed is 350 rpm, the voltage is set to 15 to 20 kV, and the distance between the needle tip and the collector is 15 cm.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] The present invention discloses a method for preparing a rotator cuff patch containing exosomes. The method uses a coaxial electrospinning method to prepare nanofibers, which mimics the ultrastructure of the extracellular matrix. At the same time, the nanofiber structure is similar to rotator cuff tissue and can mimic rotator cuff tissue. Moreover, the nanofibers have sufficient mechanical strength and elasticity to guide tissue growth in the appropriate direction and have ideal biomedical functions. Coaxial electrospinning is used to prepare core-shell structure nanofibers. The core layer contains exosomes, which can promote the migration and fusion of osteoblasts and tendon cells, and has the effect of promoting tissue healing. At the same time, the exosomes are encapsulated in the nanofiber core layer structure and are released more slowly than ordinary blended nanofibers. Therefore, the core-shell structure can slow down the release of exosomes and avoid sudden release. The present invention combines the complementary advantages of high molecular weight polymers, extracellular vesicles (exosomes), and natural collagen in terms of composition and properties, and combines the biomimetic structure of nanofibers to prepare a biomimetic rotator cuff patch with a rotator cuff structure and promoted healing.

[0026] The exosome-containing rotator cuff patch prepared by the above method of the present invention utilizes collagen, a key component of the rotator cuff, while PLGA provides sufficient mechanical strength and elasticity. Exosomes are rich in various proteins and miRNAs, participating in various biological processes and promoting the healing of rotator cuff injuries. Its advantages are primarily reflected in the following aspects: 1. The patch possesses sufficient mechanical strength and elasticity to meet the requirements of a rotator cuff patch; the fiber curvature guides tissue growth in the appropriate direction, promoting tissue repair and possessing ideal biomedical functions; 2. After tissue regeneration reaches a usable level, the patch can be completely degraded, demonstrating excellent biocompatibility; and 3. The patch contains exosomes, promoting tissue regeneration. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 This is a TEM image of the exosome-containing rotator cuff patch of Example 1 of the present invention.

[0028] Figure 2 This is the macroscopic morphology of the exosome-containing rotator cuff patch of Invention Example 1

[0029] Figure 3 This is the SEM image of the exosome-containing rotator cuff patch of Inventive Example 1.

[0030] Figure 4 This is a diagram of the in vitro cell activity of the exosome-containing rotator cuff patch of Invention Example 1. DETAILED DESCRIPTION

[0031] In order to enable those skilled in the art to better understand the solutions of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of the present invention.

[0032] It should be noted that the terms "first", "second", etc. in the description and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that the numbers used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0033] The present invention is described in further detail below with reference to the accompanying drawings:

[0034] Example 1

[0035] (1) Cell culture, exosome isolation and identification: Bone marrow mesenchymal stem cells were cultured in α-MEM medium (Hyclone) supplemented with 10% fetal bovine serum (Gibco) and 1% α-MEM medium (Hyclone) containing 100 U / ml penicillin and 0.1 mg / ml streptomycin. After growth to a cell density of 60%, the medium was changed to 5% exosome-free serum medium (SBI) and cultured for 48 h. The cell supernatant was collected and exosomes were isolated and collected using the ExoQuick-TC kit (System Bioscience). The isolated exosomes were resuspended in 1X PBS.

[0036] (2) Electrospinning was used to prepare nanofiber membranes, i.e., scapular patches. The inner layer was prepared by dissolving 1.4 g of poly(lactic-co-glycolic acid) (PLGA) with a viscosity of 1.8 dL / g in 18 g of hexafluoroisopropanol, adding 0.6 g of collagen, and stirring for 5 h at room temperature with a magnetic stirrer. The core layer was prepared by adding 2 g of poly(vinyl alcohol) (PVA) with a viscosity of 80-110 mPs to 20 g of PBS, heating the solution at 90°C and stirring for 5 h. After the solution returned to room temperature, 0.1%, 1%, and 10% of exosomes were added. The two solutions were electrospun at a rate of 2 mL / h for the shell solution and 1 mL / h for the core solution. The drum speed was 350 rpm, the voltage was set to 20 kV, and the distance between the needle tip and the collector was 15 cm.

[0037] (3) Characterization of nanofiber configuration: A copper mesh was placed on a collector to receive the electrospun nanofibers. The core-shell structure of the nanofibers was characterized by TEM. The results showed that the nanofibers had a core-shell structure ( Figure 1 ). See Figure 2 and 3 The exosome-containing rotator cuff patch prepared by the present invention has a complete overall shape, and the nanofiber composite rotator cuff tissue bionics can regulate cell growth and arrangement.

[0038] (4) Mechanical Properties: The mechanical properties of the nanofiber membranes were characterized using an electronic tensile testing machine. Each membrane was cut into five samples of 4 mm × 25 mm in size. The tensile strength was tested at a temperature of 25°C. As shown in Table 1, the tensile strength of the coaxial electrospun nanofiber membrane containing exosomes was significantly greater than that of pure PLGA. The coaxial electrospun nanofiber membrane containing exosomes has a higher tensile strength and can mimic the structure and function of natural fibers in rotator cuff tissue.

[0039] Table 1

[0040]

[0041] (5) In vitro biocompatibility of nanofiber membranes: Tendon cells were used as model cells to test the in vitro biocompatibility of different types of nanofiber membranes. The viability of tenocytes proliferating on different types of nanofiber membranes was evaluated by CCK-8 assay. The membranes were cut into 3 cm diameter circles, sterilized, and then fixed in the wells of a 24-well plate using Cell-Crown™. Tendon cells were cultured at 3 × 10 4The cells were resuspended in DMEM medium supplemented with 10% FBS and antibiotics at a density of 10 cells / ml. Then, the mixture of cell culture medium and cell suspension was inoculated onto the sample and the cells were cultured at 37°C and 5% CO2. The cell culture medium was changed every two days. On days 1, 3, 5, and 7, 100 μl of CCK-8 solution was added to the culture medium of each well and incubated for 2 hours. Then, the culture medium was transferred to a 96-well plate and the OD was measured at 450 nm. The results are shown in Figure 2. Figure 4 As shown, the cell survival rate of tenocytes treated with exosome-containing nanofiber membrane gradually increased from day 1 to day 7, and the absorbance was the highest compared with other groups, indicating that it had the best ability to promote cell proliferation.

[0042] Example 2

[0043] (1) Cell culture, exosome isolation and identification: Umbilical cord mesenchymal stem cells were cultured in DMEM / F-12 medium (Beijing Solebio Technology Co., Ltd.) supplemented with 10% fetal bovine serum (Gibco) and 1% DMEM / F-12 medium containing 100 U / ml penicillin and 0.1 mg / ml streptomycin. After growing to a cell density of 60%, the medium was changed to 5% exosome-free serum medium (SBI) and cultured for 48 h. The cell supernatant was collected and exosomes were isolated and collected using the ExoQuick-TC kit (System Bioscience). The isolated exosomes were resuspended in 1X PBS.

[0044] (2) Electrospinning was used to prepare nanofiber membranes, i.e., scapular patches. The inner layer was prepared by dissolving 1.4 g of poly(lactic-co-glycolic acid) (PLGA) with a viscosity of 1.8 dL / g in 18 g of hexafluoroisopropanol, adding 0.6 g of collagen, and stirring for 5 h at room temperature with a magnetic stirrer. The core layer was prepared by adding 2 g of poly(vinyl alcohol) (PVA) with a viscosity of 80-110 mPs to 20 g of PBS, heating the solution at 90°C and stirring for 5 h. After the solution returned to room temperature, 0.1%, 1%, and 10% of exosomes were added. The two solutions were electrospun at a rate of 2 mL / h for the shell solution and 1 mL / h for the core solution. The drum speed was 350 rpm, the voltage was set to 20 kV, and the distance between the needle tip and the collector was 15 cm.

[0045] (3) Mechanical Properties: The mechanical properties of the nanofiber membranes were characterized using an electronic tensile testing machine. Each membrane was cut into five samples of 4 mm × 25 mm in size. The tensile strength was tested at a temperature of 25°C. As shown in Table 2, the tensile strength of the coaxial electrospun nanofiber membrane containing exosomes was significantly greater than that of pure PLGA. The coaxial electrospun nanofiber membrane containing exosomes has a higher tensile strength and can mimic the structure and function of natural fibers in rotator cuff tissue.

[0046] Table 2

[0047]

[0048] Compared with Example 1, it can be seen that the mechanical properties of the exosome nanofiber membrane derived from umbilical cord mesenchymal stem cells are similar to those of the exosome nanofiber membrane derived from bone marrow mesenchymal stem cells, indicating that the effects of these two different sources of exosomes on the mechanical properties are not much different.

[0049] Example 3

[0050] (1) Cell culture, exosome isolation and identification: Umbilical cord mesenchymal stem cells were cultured in DMEM / F-12 medium (Beijing Solebio Technology Co., Ltd.) supplemented with 10% fetal bovine serum (Gibco) and 1% DMEM / F-12 medium containing 100 U / ml penicillin and 0.1 mg / ml streptomycin. After growing to a cell density of 60%, the medium was changed to 5% exosome-free serum medium (SBI) and cultured for 48 h. The cell supernatant was collected and exosomes were isolated and collected using the ExoQuick-TC kit (System Bioscience). The isolated exosomes were resuspended in 1X PBS.

[0051] (2) Electrospinning was used to prepare nanofiber membranes, i.e., scapular patches. The inner layer was prepared by dissolving 3 g of poly(lactic-co-glycolic acid) (PLGA) with a viscosity of 3 dL / g in 14 g of hexafluoroisopropanol, followed by the addition of 3 g of collagen, and stirring for 5 h at room temperature using a magnetic stirrer. The core layer was prepared by adding 4 g of poly(vinyl alcohol) (PVA) with a viscosity of 30-80 mPs to 16 g of PBS, heating the solution at 90°C and stirring for 5 h. After the solution returned to room temperature, 15% of exosomes was added. The two solutions were electrospun at a rate of 2 mL / h for the shell solution and 1 mL / h for the core solution. The drum speed was 400 rpm, the voltage was set to 20 kV, and the distance between the needle tip and the collector was 15 cm.

[0052] (3) Mechanical Properties: The mechanical properties of the nanofiber membranes were characterized using an electronic tensile testing machine. Each membrane was cut into five samples of 4 mm × 25 mm in size. The tensile strength was tested at a temperature of 25°C. As shown in Table 3, the tensile strength of the coaxial electrospun nanofiber membrane containing exosomes was significantly greater than that of pure PLGA. The coaxial electrospun nanofiber membrane containing exosomes has a higher tensile strength and can mimic the structure and function of natural fibers in rotator cuff tissue.

[0053] Table 3

[0054]

[0055] Example 4

[0056] (1) Shell spinning solution preparation: 2 g of polycaprolactone (PCL) was dissolved in 18 g of hexafluoroisopropanol and stirred with a magnetic stirrer at room temperature for 5 h;

[0057] (2) Preparation of core spinning solution: Exosome solutions of different concentrations were prepared by adding 2 g of gelatin to 18 g of PBS, heating at 37 °C with stirring for 5 h, and then adding 0.1%, 1%, and 10% exosomes after the temperature returned to room temperature.

[0058] (3) Nanofiber membranes were prepared by electrospinning. The two prepared solutions were electrospun at a rate of 2 mL / h for the shell solution and 1 mL / h for the core solution. The drum speed was 350 rpm, the voltage was set to 20 kV, and the distance between the needle tip and the collector was 15 cm.

[0059] (4) Mechanical Properties: The mechanical properties of the nanofiber membranes were characterized using an electronic tensile testing machine. Each membrane was cut into five samples of 4 mm × 25 mm in size. The tensile strength was tested at a temperature of 25°C. As shown in Table 4, the tensile strength of the coaxial electrospun nanofiber membrane containing exosomes was significantly greater than that of pure PCL. The coaxial electrospun nanofiber membrane containing exosomes has a higher tensile strength and can mimic the structure and function of natural fibers in rotator cuff tissue.

[0060] Table 4

[0061]

[0062] Example 5

[0063] (1) Shell spinning solution preparation: 6 g of polycaprolactone (PCL) was dissolved in 14 mL of hexafluoroisopropanol and stirred with a magnetic stirrer at room temperature for 5 h;

[0064] (2) Preparation of core spinning solution: Preparation of exosome solutions with different concentrations: Add 0.1 g of gelatin to 19.9 g of PBS, heat at 37 °C and stir for 5 h. After the temperature returns to room temperature, add 1% exosomes.

[0065] (3) Nanofiber membranes were prepared by electrospinning. The two prepared solutions were electrospun at a rate of 2 mL / h for the shell solution and 1 mL / h for the core solution. The drum speed was 350 rpm, the voltage was set to 20 kV, and the distance between the needle tip and the collector was 15 cm.

[0066] (4) Mechanical Properties: The mechanical properties of the nanofiber membranes were characterized using an electronic tensile testing machine. Each membrane was cut into five samples of 4 mm × 25 mm in size. The tensile strength was tested at a temperature of 25°C. As shown in Table 5, the tensile strength of the coaxial electrospun nanofiber membrane containing exosomes was significantly greater than that of pure PCL. The coaxial electrospun nanofiber membrane containing exosomes has a higher tensile strength and can mimic the structure and function of natural fibers in rotator cuff tissue.

[0067] Table 5

[0068]

[0069] The above content is only for explaining the technical idea of ​​the present invention and cannot be used to limit the protection scope of the present invention. Any changes made on the basis of the technical solution in accordance with the technical idea proposed by the present invention shall fall within the protection scope of the claims of the present invention.

Claims

1. A rotator cuff patch containing exosomes, characterized in that: The rotator cuff patch is a core-shell nanofiber membrane structure; the core layer is made of exosomes and high molecular polymers, and the shell layer is made of high molecular polymers; The raw materials for preparing the exosome-containing rotator cuff patch include, by mass percentage: In the nuclear layer: polymer is 1%-15%, exosome is 1%-20%, and phosphate buffer is 65%-92%; the polymer in the nuclear layer is gelatin or polyvinyl alcohol; In the shell layer: the high molecular polymer is 5%~30%, and the hexafluoroisopropanol is 70%~95%; the high molecular polymer in the shell layer is a mixture of polycaprolactone or polylactic acid-glycolic acid and collagen, and the mass ratio of polylactic acid-glycolic acid and collagen in the mixture of polylactic acid-glycolic acid and collagen is (5-9): (5-1).

2. The exosome-containing rotator cuff patch according to claim 1, characterized in that The viscosity of polyvinyl alcohol is 30~220mPa.s; the number average molecular weight of polycaprolactone is 10000~100000; and the viscosity of polylactic acid-glycolic acid is 0.5~3 dL / g.

3. The rotator cuff patch containing exosomes according to claim 1, characterized in that Type I collagen is used as collagen.

4. The rotator cuff patch containing exosomes according to claim 1, characterized in that The exosomes are derived from cells or body fluids, and the cells include stem cells, macrophages, endothelial cells or epithelial cells.

5. The method for preparing the rotator cuff patch containing exosomes according to any one of claims 1 to 4, characterized in that: The following steps are involved: 1) dissolving the high molecular weight polymer for preparing the shell layer in hexafluoroisopropanol and mixing thoroughly to obtain a shell layer spinning solution; 2) Add the polymer for preparing the core layer to phosphate buffer, heat and stir for 5-10 hours, and after the temperature returns to room temperature, add exosomes to prepare the core layer spinning solution; When the high molecular polymer is polyvinyl alcohol, the heating temperature is 80~100℃; when the high molecular polymer is gelatin, the heating temperature is 37℃; 3) The shell spinning solution and the core spinning solution were coaxially electrospun and sprayed onto an aluminum foil substrate to produce an exosome-containing rotator cuff patch.

6. The method for preparing the rotator cuff patch containing exosomes according to claim 5, characterized in that: In step 1), the mixture is thoroughly mixed by magnetic stirring at room temperature for 5 to 10 h.

7. The method for preparing a rotator cuff patch containing exosomes according to claim 5, wherein: In step 2), the pH value of the phosphate buffer is 7.

4.

8. The method for preparing a rotator cuff patch containing exosomes according to claim 5, wherein: In step 3), the operating parameters of the coaxial electrospinning process are: the propulsion rate of the shell spinning solution is 1-2 mL / h, the propulsion rate of the core spinning solution is 0.5-1 mL / h, the drum speed is 350 rpm, the voltage is set to 15-20 KV, and the distance between the needle tip and the collector is 15 cm.

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