A method for preparing a biodegradable patch for posterior scleral reinforcement in ophthalmology

Abstract

This application relates to the field of ophthalmic medical device technology, specifically disclosing a method for preparing a biodegradable patch for posterior scleral reinforcement in ophthalmology, comprising the following steps: extracellular matrix pretreatment; firstly, animal-derived tissues or organs are inactivated by viruses, and after antigen removal and defatting treatment, extracellular matrix without biological load is obtained; multi-layer stacking fixation: the pretreated extracellular matrix is ​​stacked in multiple layers in a mold, and fixed by applying pressure using upper and lower plane clamps at a pressure of 10-200 kPa; then, it is dried while still in the mold to obtain the biodegradable patch. The biodegradable patch obtained by the preparation method provided in this application has an ultimate load of 31.7-70.6 N and an elongation at break of 254.9-567.3%, which can meet the requirements for material strength and long-term stability in posterior scleral reinforcement surgery in ophthalmology.

Description

Technical Field

[0001] This application relates to the field of ophthalmic medical device technology, specifically to a method for preparing a biodegradable patch for posterior scleral reinforcement in ophthalmology. Background Technology

[0002] Pathological myopia is a common ophthalmic disease characterized by abnormal elongation of the axial length of the eye, leading to posterior staphyloma and various fundus lesions. This type of myopia not only manifests as an increase in myopia but is also often accompanied by damage to the retina and choroid, which can lead to severe vision loss or even blindness in severe cases. Currently, the prevention and treatment of pathological myopia has become one of the important research directions in the field of ophthalmology, among which posterior scleral reinforcement surgery has attracted much attention because it can effectively slow down the elongation of the axial length of the eye.

[0003] Currently, commonly used reinforcement materials for posterior scleral reinforcement surgery include biological materials (such as animal-derived sclera, dura mater, pericardium, etc.), synthetic materials (such as silicone, polyester fibers, etc.), and allogeneic tissues (such as allogeneic sclera, fascia lata, etc.). These materials are trimmed into appropriate shapes and implanted into the posterior pole of the eyeball to cover the weak area of ​​the posterior sclera, thereby enhancing the mechanical strength of the sclera. However, the reinforcement materials used in existing technologies generally suffer from insufficient mechanical properties, especially single-layer biological materials, which have weak strength, low solids content, and unstable thickness. These properties make it difficult to meet the high requirements for scleral reinforcement materials in the treatment of pathological myopia, affecting the long-term stability and reliability of the surgery.

[0004] Therefore, there is an urgent need to develop a scleral reinforcement material with higher strength, controllable thickness, and longer degradation time to improve the effect of post-scleral reinforcement surgery. Summary of the Invention

[0005] In order to further improve the strength of scleral reinforcement materials and extend their degradation time, this application provides a method for preparing a biodegradable patch for posterior scleral reinforcement in ophthalmology.

[0006] The method for preparing the biodegradable patch for posterior scleral reinforcement in ophthalmology provided in this application adopts the following technical solution: A method for preparing a biodegradable patch for posterior scleral reinforcement in ophthalmology includes the following steps: Extracellular matrix pretreatment: First, animal-derived tissues or organs are inactivated by viruses, and then subjected to antigen removal and defatting treatment to obtain extracellular matrix without bioburden. Multilayer stacking fixation: The pretreated extracellular matrix is ​​stacked in multiple layers in a mold and fixed by applying pressure with upper and lower plane clamps at a pressure of 10-200 kPa; then it is dried with the mold to obtain a biodegradable patch.

[0007] This application provides a method for preparing a biodegradable patch, which significantly improves the mechanical strength and thickness stability of the material and prolongs its degradation time. The resulting biodegradable patch meets the requirements for use as a posterior scleral reinforcement material in ophthalmic surgery. Specifically, this application first pre-treats the extracellular matrix to effectively remove the biological load, ensuring the safety and biocompatibility of the material. Then, the extracellular matrix is ​​stacked in multiple layers and fixed and dried under specific pressure. This causes the collagen in the extracellular matrix to lose water and its structure to change. Under pressure, partial hydrogen bond cross-linking occurs between the layers of the extracellular matrix, thereby significantly enhancing the mechanical properties of the multilayer composite biodegradable patch and greatly prolonging the degradation time. This effectively meets the requirements for material strength and long-term stability in posterior scleral reinforcement surgery.

[0008] Optionally, the drying process is either vacuum drying or freeze drying; The drying process conditions are: temperature 20-60℃, air box pressure 1-60mbar, continuous operation for 2-24h; The freeze-drying process conditions are: freeze-drying temperature -20 to -80℃, vacuum degree 0.1-100mbar, and continuous operation for 2-24 hours.

[0009] In this application, the composite extracellular matrix can be dried by freeze-drying or desiccation. Through experimental research, this application found that further freeze-drying resulted in biodegradable patches with better mechanical properties.

[0010] In some embodiments, the freeze-drying temperature can be -20 to -50°C or -50 to -80°C.

[0011] In one specific implementation, the freeze-drying temperature may also be -20°C, -50°C, or -80°C.

[0012] In some embodiments, the vacuum degree of the freeze-drying can be 0.1-20 mbar, 0.1-50 mbar, 0.1-70 mbar, 20-50 mbar, 20-70 mbar, 20-100 mbar, 50-70 mbar, 50-100 mbar, or 70-100 mbar.

[0013] In one specific implementation, the vacuum degree of the freeze-drying can also be 0.1 mbar, 20 mbar, 50 mbar, 70 mbar or 100 mbar.

[0014] In some implementations, the freeze-drying time can be 2-8h, 2-12h, 2-18h, 8-12h, 8-18h, 8-24h, 12-18h, 12-24h, or 18-24h.

[0015] In one specific implementation, the freeze-drying time can also be 2h, 8h, 12h, 18h or 24h.

[0016] Optionally, the pressure in the multi-layer stacking fixing step is 50-150 kPa.

[0017] In this application, the inventors discovered that the pressure in the multi-layer stacking and fixing step affects the mechanical properties and degradation time of the biodegradable patch. Through experimental investigation, it was found that by further controlling the pressure in the multi-layer stacking and fixing step within the above range, the biodegradable patch obtained by desiccation has an ultimate load ≥50N, an elongation at break ≥300%, and a degradation time ≥200h.

[0018] In some implementations, the fixed pressure can be 10-50 kPa, 10-100 kPa, 10-150 kPa, 50-100 kPa, 50-150 kPa, 50-200 kPa, 100-150 kPa, 100-200 kPa, or 150-200 kPa.

[0019] In one specific implementation, the fixed pressure may also be 10 kPa, 50 kPa, 100 kPa, 150 kPa or 200 kPa.

[0020] Optionally, after drying, the biodegradable patch needs to be cross-linked using genipin solution and glutaraldehyde solution.

[0021] Optionally, the number of layers in the multi-layer stack is ≥4, and the multi-layer stack is stacked in the same direction or in a cross direction; the fixed thickness after applying pressure is 0.1±0.05mm.

[0022] Optionally, the method for fixing the multi-layer stack is as follows: (1) Stack 4-6 layers of pretreated extracellular matrix into a mold, apply pressure using upper and lower plane clamps to fix it, with a pressure of 10-200 kPa; then freeze-dry with the mold to obtain biodegradable patch A; (2) Stack 4-6 layers of pretreated extracellular matrix into a mold, apply pressure using upper and lower plane clamps to fix it, with a pressure of 10-200 kPa; then dry it with the mold to obtain biodegradable patch B. (3) Soak biodegradable patch A and biodegradable patch B in water, then stack biodegradable patch A and biodegradable patch B in 2-4 layers for stacking and fixing, and freeze-dry or de-dry to obtain biodegradable patch.

[0023] In this application, since the biological patch obtained by desiccation has higher strength and the biological patch obtained by freeze-drying has higher softness, this application can obtain a biological patch that balances strength and softness by cross-stacking and fixing the biological patches obtained by desiccation and freeze-drying. This can meet the strength requirements of posterior scleral reinforcement surgery while avoiding risks such as eye damage and bleeding.

[0024] Optionally, step (3) is as follows: soak biodegradable patch A and / or biodegradable patch B in water, then stack biodegradable patches of the same type or cross-stack biodegradable patches of different types; then stack and fix them, and freeze-dry or de-dry them to obtain biodegradable patches; When the biodegradable patches are stacked or cross-stacked and fixed, a layer material is evenly placed between two adjacent biodegradable patches; the layer material is selected from one or more of elastin, silk fibroin, type I collagen, type III collagen, gelatin, sodium hyaluronate, chitosan, carboxymethyl chitosan and carboxymethyl cellulose. The weight ratio of the interlayer material to the two patches is (0.05-1):1.

[0025] Optionally, the animal is selected from humans, cattle, pigs, and sheep; the tissue or organ is selected from the sclera, dermis, small intestine, bladder basement membrane, and dura mater.

[0026] Secondly, this application provides a method for preparing a biodegradable patch, wherein the biodegradable patch has an ultimate load of 31.7-70.6 N and an elongation at break of 254.9-567.3%.

[0027] Thirdly, this application provides an eye tissue graft comprising a biodegradable patch obtained by the method for preparing the biodegradable patch described above.

[0028] In summary, this application has the following beneficial effects: 1. This application obtains a biodegradable patch with an ultimate load of 31.7-70.6 N, an elongation at break of 254.9-567.3%, and an in vitro accelerated degradation time of 150-250 min by stacking multiple layers of extracellular matrix and fixing and drying it under a pressure of 10-200 kPa. This biodegradable patch can meet the requirements for material strength and long-term stability in posterior scleral reinforcement surgery.

[0029] 2. This application further controls the pressure in the multi-layer stacking and fixing step within the range of 50-150 kPa, and the ultimate load of the biodegradable patch obtained by desiccation is ≥50 N, the elongation at break is ≥300%, and the degradation time is ≥200 h.

[0030] 3. This application further employs a vacuum freezing process to dry the composite extracellular matrix, and controls the temperature in the freeze-drying step to -20 to -80°C, the vacuum degree to 20-70 mbar, and the time to 8-18 h. The resulting biodegradable patch has higher strength and lower hardness. The ultimate load of the obtained biodegradable patch is ≥50 N, the elongation at break is ≥400%, and the hardness is <20 HRC. Detailed Implementation

[0031] This application provides a biodegradable patch for posterior scleral reinforcement in ophthalmology, the preparation method of which includes the following steps: (1) Extracellular matrix pretreatment: First, the animal-derived tissues or organs are inactivated by virus, and then subjected to antigen removal and defatting treatment to obtain a biologically free extracellular matrix; wherein, the animals are selected from humans, cattle, pigs and sheep, the tissues or organs are selected from sclera, dermis, small intestine, bladder basement membrane and dura mater, the virus inactivation reagent is selected from one or more of hydrogen peroxide, peracetic acid solution and ethanol, the antigen removal reagent is selected from one or more of hypertonic saline solution, SDS solution or enzyme solution; the defatting reagent is selected from one or more of n-hexane, chloroform, dichloromethane, methanol, ethanol, acetone and diethyl ether; (2) Multilayer stacking fixation: The pretreated extracellular matrix is ​​stacked in multiple layers in a mold and fixed by applying pressure with upper and lower plane clamps at a pressure of 10-200 kPa; then it is dried with the mold to obtain a biodegradable patch; wherein the drying is vacuum drying or freeze drying, and the process conditions are as follows; The drying process conditions are: temperature 20-60℃, air box pressure 1-60mbar, continuous operation for 2-24h; The freeze-drying process conditions are: freeze-drying temperature -20 to -80℃, vacuum degree 0.1-100mbar, and continuous operation for 2-24 hours.

[0032] The step of fixing the multi-layer stack can also be: (2-1) Stack 4-6 layers of pretreated extracellular matrix into a mold, apply pressure using upper and lower plane clamps to fix it, with a pressure of 10-200 kPa; then freeze-dry with the mold to obtain biodegradable patch A; (2-2) Stack 4-6 layers of pretreated extracellular matrix into a mold, apply pressure using upper and lower plane clamps to fix it, with a pressure of 10-200 kPa; then dry it with the mold to obtain biodegradable patch B. (2-3) Soak biodegradable patch A and biodegradable patch B in water, then stack biodegradable patch A and biodegradable patch B in 2-4 layers for fixation, and freeze-dry or de-dry to obtain biodegradable patch.

[0033] In this application, the number of overlapping layers is calculated as one layer for each "single biodegradable patch".

[0034] Further, step (3) is as follows: soak biodegradable patch A and / or biodegradable patch B in water, then stack biodegradable patches of the same type or cross-stack biodegradable patches of different types; then stack and fix them, and freeze-dry or de-dry to obtain biodegradable patches; When the biodegradable patches are stacked or cross-stacked and fixed, a layer material is evenly placed between two adjacent biodegradable patches; the layer material is selected from one or more of elastin, silk fibroin, type I collagen, type III collagen, gelatin, sodium hyaluronate, chitosan, carboxymethyl chitosan and carboxymethyl cellulose. The weight ratio of the interlayer material to the two patches is (0.05-1):1.

[0035] Furthermore, after drying, the biodegradable patch can be cross-linked using genipin solution and glutaraldehyde solution.

[0036] The raw materials, reagents, solvents, etc. used in this application can all be obtained commercially.

[0037] The present application will be further described in detail below with reference to embodiments and performance testing.

[0038] Examples 1-5 Examples 1-5 each provide a method for preparing a biodegradable patch.

[0039] The difference in the above embodiments is that the fixing pressure in the multi-layer stacking fixing step is as shown in Table 1 below.

[0040] The preparation method of the biodegradable patch provided in Examples 1-5 includes the following steps: (1) Pretreatment of extracellular matrix: Fresh biological tissue, submucosa of pig small intestine, was taken, virus was inactivated by 4% hydrogen peroxide, then antigen was removed by 1% SDS solution, and defatted by ethanol to obtain extracellular matrix without biological load. (2) Multilayer stacking fixation: The pretreated extracellular matrix is ​​stacked in the same direction in 6 layers and placed in the mold. Pressure is applied by the upper and lower plane clamps for fixation. The pressure is 10-200 kPa and the fixation thickness is 0.1±0.05 mm. Then, the mold is dried. The drying process conditions are: temperature 38℃, wind box pressure 1-20 mbar, continuous action for 4 hours. Finally, it is cut into 15×10 cm biodegradable patches.

[0041] Table 1 shows the pressure required for multi-layer stacking and fixing in the preparation methods provided in Examples 1-5. 1 10 2 50 3 100 4 150 5 200 Examples 6-10 Examples 6-10 each provide a method for preparing a biodegradable patch.

[0042] The difference between the above embodiment and embodiment 3 is that the number of layers and the stacking direction of the multi-layer stack are as shown in Table 2 below.

[0043] Table 2 shows the number of layers and stacking direction in Examples 6-10. Example 11 Example 11 provides a method for preparing a biodegradable patch.

[0044] The difference between the above embodiment and embodiment 3 is that the drying method is replaced by freeze drying. The freeze drying process conditions are: freeze drying temperature -50℃, vacuum degree 50mbar, and continuous action for 12h.

[0045] Examples 12-21 Examples 12-21 provide a method for preparing a biodegradable patch.

[0046] The difference between the above embodiments and Embodiment 11 is that the freeze-drying process conditions are shown in Table 3 below.

[0047] Table 3. Freeze-drying process conditions in the preparation methods of Examples 12-21 Example 22 Example 22 provides a method for preparing a biodegradable patch.

[0048] The preparation method of the above-mentioned biodegradable patch includes the following steps: (1) Pretreatment of extracellular matrix: Fresh biological tissue, submucosa of pig small intestine, was taken, and virus was inactivated by hydrogen peroxide. Then, SDS solution was used to remove antigens and ethanol was used for defatting to obtain extracellular matrix without biological load. (2) Multi-layer stacking fixation: (2-1) The pretreated extracellular matrix was stacked in the same direction in four layers and placed in a mold. Pressure was applied using upper and lower plane clamps to fix it. The pressure was 100 kPa and the fixation thickness was 0.1 ± 0.05 mm. Then, the mold was used for freeze drying. The freeze drying process conditions were: freeze drying temperature -50℃, vacuum degree 50 mbar, continuous action for 12 h. Finally, it was cut into 15 × 10 cm biodegradable patch A, and two patches were prepared. (2-2) The pretreated extracellular matrix was stacked in the same direction in four layers and placed in a mold. Pressure was applied using upper and lower plane clamps to fix it. The pressure was 100 kPa and the fixation thickness was 0.1 ± 0.05 mm. Then, the mold was used for desiccation. The desiccation process conditions were: temperature 38℃, wind box pressure 1-20 mbar, continuous action for 4 hours. Finally, it was cut into 15 × 10 cm biodegradable patch B. (2-3) Wet the surfaces of biodegradable patch A and biodegradable patch B with water, then stack them in four layers in a mold (i.e., biodegradable patch A-biodegradable patch B-biodegradable patch A), and fix them with pressure applied by the upper and lower plane clamps. The pressure is 100 kPa and the fixation thickness is 0.1 ± 0.05 mm. Then freeze-dry them with the mold. The freeze-drying process conditions are: freeze-drying temperature -50℃, vacuum degree 50 mbar, continuous action for 12 h, and finally cut them into 15×10 cm biodegradable patches.

[0049] Example 23 Example 23 provides a method for preparing a biodegradable patch.

[0050] The preparation method of the above-mentioned biodegradable patch includes the following steps: The preparation method of the above-mentioned biodegradable patch includes the following steps: (1) Pretreatment of extracellular matrix: Fresh biological tissue, submucosa of pig small intestine, was taken, and virus was inactivated by hydrogen peroxide. Then, SDS solution was used to remove antigens and ethanol was used for defatting to obtain extracellular matrix without biological load. (2) Multi-layer stacking fixation: (2-1) The pretreated extracellular matrix was stacked in the same direction in four layers and placed in a mold. Pressure was applied using upper and lower plane clamps to fix it. The pressure was 100 kPa and the fixation thickness was 0.1 ± 0.05 mm. Then, the mold was used for freeze drying. The freeze drying process conditions were: freeze drying temperature -50℃, vacuum degree 50 mbar, continuous action for 12 h. Finally, it was cut into 15 × 10 cm biodegradable patch A, and two patches were prepared. (2-2) The pretreated extracellular matrix was stacked in the same direction in four layers and placed in a mold. Pressure was applied using upper and lower plane clamps to fix it. The pressure was 100 kPa and the fixation thickness was 0.1 ± 0.05 mm. Then, the mold was used for desiccation. The desiccation process conditions were: temperature 38℃, wind box pressure 1-20 mbar, continuous action for 4 hours. Finally, it was cut into 15 × 10 cm biodegradable patch B. (2-3) Wet the surfaces of biodegradable patch A and biodegradable patch B, then stack them in four layers in a mold, with interlayer material evenly placed between two adjacent biodegradable patches (i.e., biodegradable patch A - interlayer material - biodegradable patch B). Fix them by applying pressure with upper and lower plane clamps at a pressure of 100 kPa and a fixing thickness of 0.1 ± 0.05 mm. Then freeze-dry them in the mold. The freeze-drying process conditions are: freeze-drying temperature -50℃, vacuum degree 50 mbar, continuous action for 12 h. Finally, cut them into 15 × 10 cm biodegradable patches. The interlayer material is silk fibroin, and the weight ratio of silk fibroin to the two patches is 0.5:1.

[0051] Comparative Example 1 Comparative Example 1 provides a method for preparing a biodegradable patch.

[0052] The preparation method of the above-mentioned biodegradable patch includes the following steps: (1) Pretreatment of extracellular matrix: Fresh biological tissue, submucosa of pig small intestine, was taken, and virus was inactivated by hydrogen peroxide. Then, SDS solution was used to remove antigens and ethanol was used for defatting to obtain extracellular matrix without biological load. (2) Stacking and fixing: The pretreated extracellular matrix monolayer is placed in the mold and fixed by applying pressure with upper and lower plane clamps. The pressure is 100 kPa and the fixing thickness is 0.1 ± 0.05 mm. Then, the mold is dried. The drying process conditions are: temperature 40℃, wind box pressure 30 mbar, continuous action for 12 h. Finally, it is cut into 15 × 10 cm biodegradable patches.

[0053] Performance testing The tensile and degradation properties of the biodegradable patches obtained in Examples 1-23 and Comparative Example 1 were tested, and the results are shown in Table 4.

[0054] (1) Tensile test: The biodegradable patch was cut into 1×5cm test strips, and then the ultimate load and elongation at break of the biodegradable patch in the wet state were tested using a universal tensile testing machine under normal temperature and pressure, sensor 1000 Newton, and loading speed of 10mm / min. Each group of samples was repeated 5 times and the average value was taken.

[0055] (2) Degradation test: The biodegradable patch was cut into 4×6cm test pieces and tested under in vitro degradation conditions (PBS buffer, proteinase K concentration 1mg / ml, 56℃, shaker speed 60r / min). The test was conducted every 10min and the complete degradation time of each biodegradable patch was recorded. Each group of samples was repeated 5 times and the average value was taken.

[0056] (3) Hardness test: The hardness is tested using a Rockwell hardness tester. Place the sample on the stage of the hardness tester and make stable contact with the indenter. Apply the initial load, maintain the main load for 10 seconds, then unload the main load and read the Rockwell hardness value. Repeat the test 5 times at random test positions and take the average value.

[0057] Table 4 Performance test results of the biodegradable patches obtained in Examples 1-23 and Comparative Example 1 According to the test results in Table 4, the biodegradable patches prepared in Examples 1-23 of this application have an ultimate load of 31.7-70.6 N, an elongation at break of 254.9-567.3%, a degradation time of 150-250 min, and a surface hardness <95 HRC. In contrast, the biodegradable patch obtained in Comparative Example 1 has an ultimate load of only 2.28 N, an elongation at break of only 70.4%, and a degradation time of only 90 min. This indicates that the biodegradable patch prepared in this application, through multi-layer stacking and fixation of the extracellular matrix, possesses excellent mechanical properties and a long degradation time, meeting the requirements for material strength and long-term stability in posterior scleral reinforcement surgery.

[0058] The test results of Examples 3 and 11 showed that the ultimate load and elongation at break of the biodegradable patch obtained by desiccation in Example 3 were better than those of the biodegradable patch obtained by freeze-drying in Example 11; however, the hardness of the biodegradable patch obtained by freeze-drying in Example 11 was better than that of the biodegradable patch obtained by desiccation in Example 3.

[0059] Further comparison of the test results of Examples 11-21 revealed that the ultimate load of the biodegradable patches obtained in Examples 11-13, 15-16, and 19-20 was 40.6-47.5 N (≥40 N), and the elongation at break was 402.2-451.6% (≥400%). Therefore, considering both time and economic cost, this application demonstrates that by further controlling the temperature in the freeze-drying step to -20 to -80°C, the vacuum degree to 20-70 mbar, and the time to 8-18 h, a biodegradable patch with higher strength and better softness can be obtained.

[0060] Although the present invention has been described in detail above with general descriptions and specific embodiments, modifications or improvements can be made to it, which will be obvious to those skilled in the art. Therefore, all such modifications or improvements made without departing from the spirit of the present invention fall within the scope of protection claimed by the present invention.

Claims

1. A method for preparing a biodegradable patch for posterior scleral reinforcement in ophthalmology, characterized in that, Includes the following steps: Extracellular matrix pretreatment: First, animal-derived tissues or organs are inactivated by viruses, and then subjected to antigen removal and defatting treatment to obtain extracellular matrix without bioburden. Multi-layer stacking fixation: (1) Stack 4-6 layers of pretreated extracellular matrix into a mold, apply pressure with upper and lower plane clamps to fix it, and apply pressure of 10-200 kPa; then freeze dry with the mold to obtain biodegradable patch A; (2) Stack 4-6 layers of pretreated extracellular matrix into a mold, apply pressure with upper and lower plane clamps to fix it, and apply pressure of 10-200 kPa; then dry it with the mold to obtain biodegradable patch B; (3) Soak biodegradable patch A and biodegradable patch B in water, then stack biodegradable patch A and biodegradable patch B in 2-4 layers for stacking and fixing, and freeze-dry or de-dry to obtain biodegradable patch; Step (3) can also be: soaking biodegradable patch A and / or biodegradable patch B in water, then stacking biodegradable patches of the same type or cross-stacking biodegradable patches of different types; then stacking and fixing, and then freeze-drying or de-drying to obtain biodegradable patches; When the layers are stacked or cross-stacked and fixed, a layer of interlayer material is evenly placed between two adjacent biodegradable patches. The interlayer material is selected from one or more of elastin, silk fibroin, type I collagen, type III collagen, gelatin, sodium hyaluronate, chitosan, carboxymethyl chitosan, and carboxymethyl cellulose. The weight ratio of the interlayer material to the two patches is (0.05-1):

1.

2. The method for preparing the biodegradable patch according to claim 1, characterized in that, The drying process conditions are: temperature 20-60℃, air box pressure 1-60mbar, continuous operation for 2-24h; The freeze-drying process conditions are: freeze-drying temperature -20~-80℃, vacuum degree 0.1-100mbar, and continuous operation for 2-24 hours.

3. The method for preparing the biodegradable patch according to claim 1, characterized in that, The pressure during the multi-layer stacking and fixing step is 50-150 kPa.

4. The method for preparing the biodegradable patch according to claim 1, characterized in that, After freeze-drying or de-drying, the biodegradable patch needs to be cross-linked using genipin solution and glutaraldehyde solution.

5. The method for preparing the biodegradable patch according to claim 1, characterized in that, The fixed thickness after applying pressure is 0.1 ± 0.05 mm.

6. The method for preparing the biodegradable patch according to any one of claims 1-5, characterized in that, The animals are selected from humans, cattle, pigs, and sheep; the tissues or organs are selected from the sclera, dermis, small intestine, bladder basement membrane, and dura mater.

7. The biodegradable patch obtained by the preparation method of any one of claims 1-6, characterized in that, The biodegradable patch has an ultimate load of 31.7-70.6 N and an elongation at break of 254.9-567.3%.

8. An eye tissue graft, characterized in that, A biodegradable patch obtained by the preparation method of any one of claims 1-6.

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