Anti-adhesion film and preparation method and application thereof

Abstract

The present application relates to a kind of anti-adhesion film and its preparation method and application, the preparation raw material of the anti-adhesion film includes magnetic starch nanoparticles.The present application is prepared porous gelatin anti-adhesion film using emulsion method, with magnetic degradable nanoparticles as magnetic filler, gelatin as matrix, and porous gelatin anti-adhesion film is prepared.The pore size distribution of the obtained anti-adhesion film is uniform, has very strong water absorption performance and protein adsorption capacity, can effectively prevent the occurrence of postoperative tissue adhesion, lays foundation for its application in postoperative tissue anti-adhesion field.

Description

Technical Field

[0001] This invention relates to the field of medical materials, and in particular to an anti-adhesion membrane, its preparation method, and its application. Background Technology

[0002] Adhesions are abnormal fibrous bands between adjacent parts or structures of the body, usually caused by inflammation or surgical trauma. Post-gynecological surgery adhesions are a major cause of chronic or recurrent pain in many women, considered a leading cause of infertility, and bowel obstruction, often requiring surgical intervention, is the most serious complication of intraperitoneal adhesions. The most common cause of adhesions is previous surgery leading to new adhesions or adhesive remodeling at the site of previous adhesion release. In such cases, repeated surgeries are required to release the adhesions, increasing the risk of iatrogenic organ damage. Repeated surgical interventions are complex, time-consuming, and carry a risk of severe bleeding and tissue damage. Researchers have conducted extensive studies to identify effective methods or ideal materials for preventing postoperative adhesions. Researchers have attempted to address adhesion problems through systemic antibiotics, antihistamines, and corticosteroids; however, all of these drugs have side effects, and their relative ability to prevent or reduce adhesion formation is largely theoretical rather than clinically proven.

[0003] To reduce postoperative adhesions, current research focuses on the use of physical barriers that can isolate damaged areas of adjacent structures, thereby reducing tissue adhesions. It is generally believed that ideal postoperative adhesion prevention involves physical barriers that adhere stably to the wound site during healing. Therefore, the development of anti-adhesion membranes has become a key issue in medical science. Natural polymers such as gelatin, collagen, hyaluronic acid, chondroitin sulfate, and oxidized regenerated cellulose, as well as synthetic polymers such as poly(tetrafluoroethylene), polyvinyl alcohol, and polyhydroxyalkanoates, have been developed and designed as physical barriers.

[0004] Magnetic materials possess excellent magnetic conductivity, biocompatibility, and biodegradability, attracting widespread attention from researchers in the biomedical field. Because magnetic materials also promote healing—by creating a constant magnetic field to encourage wound tissue growth and regeneration while simultaneously reducing pain and inflammation—researchers have combined magnetic materials with biomedical technology to prepare magnetic anti-adhesion membranes, aiming to promote wound healing and alleviate pain.

[0005] Anti-adhesion membranes have several requirements, the most important of which include good biocompatibility, a suitable degradation rate, and good barrier properties against fibroblast permeation. Gelatin is a degradation product of collagen, which can be rapidly absorbed in the body, is non-immunogenic, and has cell binding sites, promoting cell adhesion, proliferation, and differentiation. Its molecular structure contains numerous hydroxyl, amino, and carboxyl groups, making it an amphoteric substance with strong hydrophilicity and adhesive properties, allowing it to adhere well to wound surfaces. Starch is a plant polysaccharide with good biocompatibility, is non-toxic, non-irritating, and unlikely to cause allergic reactions in the body, and has extremely strong water absorption.

[0006] Currently available anti-adhesion films such as polylactic acid (PLA), sodium carboxymethyl cellulose (CMC), and cellulose oxide (COD) still have some drawbacks. PLA has poor adhesion to tissues, and its degradation product, lactic acid, can easily cause acid accumulation and trigger inflammation. CMC has a relatively fast absorption cycle and poor mechanical properties in a humid environment. COD requires thorough hemostasis before use and cannot be used in cases of local bleeding. Furthermore, most existing anti-adhesion products are manufactured using a casting process, resulting in low porosity, which hinders intercellular material exchange and may lead to more severe inflammatory reactions, increasing the risk of adhesion. Existing emulsion-cast porous anti-adhesion film methods also suffer from surfactant residue issues. Summary of the Invention

[0007] The problem the invention aims to solve

[0008] To address the aforementioned problems in the existing technology, the purpose of this invention is to provide a porous anti-adhesion membrane with good water absorption and protein adsorption capabilities.

[0009] Solution for solving the problem

[0010] The present invention provides an anti-adhesion membrane, characterized in that the raw material for preparing the anti-adhesion membrane includes magnetic starch nanoparticles, and the preparation method of the magnetic starch nanoparticles includes: adding an aqueous hydroxide solution to a solution containing starch and metal ions, then adding an oxidant dropwise, neutralizing, separating, washing, and drying.

[0011] Preferably, the preparation method of the magnetic starch nanoparticles includes the following steps:

[0012] (1) Dissolve starch in water, continuously pass in inert gas, and then slowly add a solution containing metal ions while stirring;

[0013] (2) After the reaction in step (1) is completed, centrifuge the precipitate, suspend it in water, and add an aqueous hydroxide solution to adjust the pH.

[0014] (3) When the solution color changes, add oxidant dropwise to a water bath. Stop adding dropwise and stir after the solution changes color.

[0015] (4) Cool the solution to room temperature and adjust the pH, centrifuge, wash the precipitate, and dry to obtain the magnetic starch nanoparticles.

[0016] Preferably, the starch in step (1) is nano-sized starch; more preferably, the starch is modified nano-sized starch with a particle size of 1-1000 nm.

[0017] Preferably, the inert gas in step (1) is nitrogen;

[0018] Preferably, the solution containing metal ions in step (1) is a ferrous chloride solution;

[0019] Preferably, the aqueous hydroxide solution in step (2) is a sodium hydroxide solution;

[0020] Preferably, the pH adjustment in step (2) is to adjust the pH to 10-12;

[0021] Preferably, the oxidant in step (3) is a hydrogen peroxide solution;

[0022] Preferably, the pH adjustment in step (4) is to adjust the pH to neutral.

[0023] Preferably, the raw materials for preparing the anti-adhesion film further include gelatin and / or an oil phase and / or a crosslinking agent and / or a solvent;

[0024] Preferably, the oil phase is selected from one or more of liquid paraffin, vegetable oil, and ethyl acetate; more preferably, the oil phase is liquid paraffin.

[0025] Preferably, the crosslinking agent is selected from one or more of formaldehyde, glyoxal, malondialdehyde, succinaldehyde, glutaraldehyde, genipin, and 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide (EDC); more preferably, the crosslinking agent is glyoxal and / or glutaraldehyde.

[0026] Preferably, the solvent is selected from one or more of water, methanol, ethanol, isopropanol, n-butanol, acetone, acetonitrile, and tetrahydrofuran; more preferably, the solvent is water and / or ethanol.

[0027] Preferably, the thickness of the anti-adhesion film is 0.1-2 mm; more preferably, the thickness of the anti-adhesion film is 0.1-0.5 mm; even more preferably, the thickness of the anti-adhesion film is 0.2-0.3 mm.

[0028] The present invention also provides a method for preparing the anti-adhesion film, wherein the method is an emulsion method and the emulsion method does not use surfactants.

[0029] Preferably, the method includes:

[0030] (a) Add the magnetic starch nanoparticles to water, sonicate, and prepare a suspension;

[0031] (b) Add gelatin aqueous solution to the suspension prepared in step (a), stir evenly to obtain the aqueous phase;

[0032] (c) Add the oil phase to the aqueous phase prepared in step (b), stir and cast into a film, and after standing at room temperature, obtain an uncrosslinked film;

[0033] (d) The uncrosslinked membrane is immersed in an ethanol solution of a crosslinking agent, kept at room temperature, and then washed and dried to obtain the anti-adhesion membrane.

[0034] Preferably, the concentration of the magnetic starch nanoparticles in the aqueous phase is 0.1 wt%-5 wt%; more preferably, the concentration of the magnetic starch nanoparticles in the aqueous phase is 0.5 wt%-1 wt%.

[0035] Preferably, the concentration of the suspension in step (a) is 0.01-0.1 wt%, more preferably, the concentration of the suspension is 0.05 wt%.

[0036] Preferably, the concentration of the gelatin aqueous solution in step (b) is 5-30 wt%, more preferably, the concentration of the gelatin aqueous solution is 10 wt%.

[0037] Preferably, the volume ratio of the oil phase to the water phase in step (c) is 2:1 to 1:10; more preferably, the volume ratio of the oil phase to the water phase is 1:5.

[0038] Preferably, the concentration of the ethanol solution of the crosslinking agent in step (d) is 0.2-2 wt%; more preferably, the concentration of the ethanol solution of the crosslinking agent is 0.5-1 wt%.

[0039] The present invention also provides the application of the anti-adhesion membrane or the preparation method thereon in the preparation of tissue and organ repair products for humans or animals.

[0040] The effects of the invention

[0041] This invention employs an emulsion method to prepare a porous gelatin anti-adhesion membrane. Magnetic biodegradable nanoparticles are used as magnetic fillers, and gelatin is used as the matrix. The resulting anti-adhesion membrane has a uniform pore size distribution and exhibits strong water absorption and protein adsorption capabilities, effectively preventing postoperative tissue adhesion and laying the foundation for its application in the field of postoperative tissue adhesion prevention. Attached Figure Description

[0042] Figure 1 This is a cross-sectional scanning electron microscope image of the anti-adhesion film of Example 1.

[0043] Figure 2 This is a cross-sectional scanning electron microscope image of the anti-adhesion film in Example 2.

[0044] Figure 3 This is a cross-sectional scanning electron microscope image of the anti-adhesion film of Example 3.

[0045] Figure 4 This is a cross-sectional scanning electron microscope image of the anti-adhesion membrane in Comparative Example 1.

[0046] Figure 5 The results are for the control group in the characterization of anti-adhesion performance.

[0047] Figure 6 The results are the test results of the experimental group in characterizing its anti-adhesion performance. Detailed Implementation

[0048] To make the technical solution and beneficial effects of the present invention more apparent and understandable, a detailed description is provided below by listing specific embodiments. The accompanying drawings are not necessarily drawn to scale, and local features may be enlarged or reduced to more clearly show the details of the local features; unless otherwise defined, the technical and scientific terms used herein have the same meanings as those in the technical field to which this application pertains.

[0049] Unless otherwise stated, experimental methods in the following examples without specific conditions are generally performed under conventional conditions or as recommended by the manufacturer. Unless otherwise stated, all percentages, ratios, proportions, or parts are by weight. Unless otherwise stated, the room temperature described in this invention is 20°C to 30°C. Unless otherwise stated, the various materials and reagents used in this invention can be obtained using conventional methods in the art or through commercial channels.

[0050] The present invention provides an anti-adhesion membrane, characterized in that the raw material for preparing the anti-adhesion membrane includes magnetic starch nanoparticles, and the preparation method of the magnetic starch nanoparticles includes: adding an aqueous hydroxide solution to a solution containing starch and metal ions, then adding an oxidant dropwise, neutralizing, separating, washing, and drying.

[0051] In some embodiments, the preparation method of the magnetic starch nanoparticles includes the following steps:

[0052] (1) Dissolve starch in water, continuously pass in inert gas, and then slowly add a solution containing metal ions while stirring;

[0053] (2) After the reaction in step (1) is completed, centrifuge the precipitate, suspend it in water, and add an aqueous hydroxide solution to adjust the pH.

[0054] (3) When the solution color changes, add oxidant dropwise to a water bath. Stop adding dropwise and stir after the solution changes color.

[0055] (4) Cool the solution to room temperature and adjust the pH, centrifuge, wash the precipitate, and dry to obtain the magnetic starch nanoparticles.

[0056] In some embodiments, the starch in step (1) is nano-sized starch.

[0057] In some embodiments, the starch in step (1) is a modified nano-sized starch with a particle size of 1-1000 nm.

[0058] In some embodiments, the inert gas in step (1) is nitrogen.

[0059] In some embodiments, the solution containing metal ions in step (1) is a solution containing iron ions.

[0060] In some embodiments, the solution containing metal ions in step (1) is a ferrous chloride solution.

[0061] In some embodiments, the solution containing metal ions in step (1) is a 0.5M ferrous chloride solution.

[0062] In some embodiments, the stirring in step (1) is performed at 800-1200 rpm for 1-4 hours.

[0063] In some embodiments, the stirring in step (1) is performed at 1000 rpm for 2 hours.

[0064] In some embodiments, the centrifugation in step (2) is performed by centrifuging at 3000-4000 r / min 1-3 times.

[0065] In some embodiments, the centrifugation in step (2) is performed by centrifuging twice at 3500 r / min.

[0066] In some embodiments, the aqueous hydroxide solution in step (2) is a sodium hydroxide solution.

[0067] In some embodiments, the aqueous hydroxide solution in step (2) is a 0.5M sodium hydroxide solution.

[0068] In some implementations, step (2) involves adjusting the pH to 9-12.

[0069] In some implementations, step (2) of adjusting the pH means adjusting the pH to 9, or 9.5, or 10, or 10.5, or 11, or 11.5, or 12.

[0070] In some implementations, step (2) of adjusting the pH means adjusting the pH to 10.

[0071] In some implementations, the water bath in step (3) is a 65°C water bath.

[0072] In some embodiments, the oxidant in step (3) is a hydrogen peroxide solution.

[0073] In some embodiments, the hydrogen peroxide solution in step (3) is a 10-30% hydrogen peroxide solution.

[0074] In some embodiments, the hydrogen peroxide solution in step (3) is a hydrogen peroxide solution of 10%, or 11%, or 12%, or 13%, or 14%, or 15%, or 16%, or 17%, or 18%, or 19%, or 20%, or 21%, or 22%, or 23%, or 24%, or 25%, or 26%, or 27%, or 28%, or 29%, or 30%.

[0075] In some embodiments, the hydrogen peroxide solution in step (3) is a 20% hydrogen peroxide solution.

[0076] In some embodiments, the stirring in step (3) is stirring for 30-90 minutes.

[0077] In some embodiments, the stirring in step (3) is stirring for 60 minutes.

[0078] In some implementations, step (4) of adjusting the pH means adjusting the pH to neutral.

[0079] In some implementations, step (4) involves adjusting the pH to neutral using an acidic solution.

[0080] In some implementations, step (4) involves adjusting the pH to neutral using glacial acetic acid.

[0081] In some embodiments, the centrifugation in step (4) is performed by centrifuging at 3000-4000 r / min 1-3 times.

[0082] In some embodiments, the centrifugation in step (4) is performed twice at 3500 r / min.

[0083] In some embodiments, the cleaning in step (4) involves cleaning with an alcohol solution 1-3 times.

[0084] In some embodiments, the cleaning in step (4) involves cleaning three times with an 80% alcohol solution.

[0085] In some embodiments, the drying in step (4) is a constant temperature drying at 45°C.

[0086] In some embodiments, the raw materials for preparing the anti-adhesion film also include gelatin and / or an oil phase and / or a crosslinking agent and / or a solvent.

[0087] In some embodiments, the oil phase is selected from one or more of liquid paraffin, vegetable oil, and ethyl acetate.

[0088] In some embodiments, the oil phase is liquid paraffin.

[0089] In some embodiments, the crosslinking agent is selected from one or more of formaldehyde, glyoxal, malondialdehyde, succinaldehyde, glutaraldehyde, genipin, and 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide (EDC).

[0090] In some embodiments, the crosslinking agent is glyoxal and / or glutaraldehyde.

[0091] In some embodiments, the crosslinking agent is glyoxal and glutaraldehyde.

[0092] In some embodiments, the crosslinking agent is glyoxal.

[0093] In some embodiments, the crosslinking agent is glutaraldehyde.

[0094] In some embodiments, the solvent is selected from one or more of water, methanol, ethanol, isopropanol, n-butanol, acetone, acetonitrile, and tetrahydrofuran.

[0095] In some embodiments, the solvent is water and / or ethanol.

[0096] In some embodiments, the solvent is water and ethanol.

[0097] In some embodiments, the solvent is water.

[0098] In some embodiments, the solvent is ethanol.

[0099] In some embodiments, the thickness of the anti-adhesion film is 0.1-2 mm.

[0100] In some embodiments, the thickness of the anti-adhesion film is 0.1 mm, or 0.2 mm, or 0.3 mm, or 0.4 mm, or 0.5 mm, or 0.6 mm, or 0.7 mm, or 0.8 mm, or 0.9 mm, or 1 mm, or 1.2 mm, or 1.3 mm, or 1.4 mm, or 1.5 mm, or 1.6 mm, or 1.7 mm, or 1.8 mm, or 1.9 mm, or 2 mm.

[0101] In some embodiments, the thickness of the anti-adhesion film is 0.1-0.5 mm.

[0102] In some embodiments, the thickness of the anti-adhesion film is 0.2-0.3 mm.

[0103] The present invention also provides a method for preparing the anti-adhesion film, wherein the method is an emulsion method and the emulsion method does not use surfactants.

[0104] In some embodiments, the method includes:

[0105] (a) Add the magnetic starch nanoparticles to water, sonicate, and prepare a suspension;

[0106] (b) Add gelatin aqueous solution to the suspension prepared in step (a), stir evenly to obtain the aqueous phase;

[0107] (c) Add the oil phase to the aqueous phase prepared in step (b), stir and cast into a film, and after standing at room temperature, obtain an uncrosslinked film;

[0108] (d) The uncrosslinked membrane is immersed in an ethanol solution of a crosslinking agent, kept at room temperature, and then washed and dried to obtain the anti-adhesion membrane.

[0109] In some embodiments, the concentration of the magnetic starch nanoparticles in the aqueous phase is 0.1 wt% to 5 wt%.

[0110] In some embodiments, the concentration of the magnetic starch nanoparticles in the aqueous phase is 0.1 wt%, or 0.2 wt%, or 0.3 wt%, or 0.4 wt%, 0.5 wt%, or 0.6 wt%, or 0.7 wt%, or 0.8 wt%, or 0.9 wt%, or 1 wt%, or 1.5 wt%, or 2 wt%, or 2.5 wt%, or 3 wt%, or 3.5 wt%, or 4 wt%, or 4.5 wt%, or 5 wt%.

[0111] In some embodiments, the concentration of the magnetic starch nanoparticles in the aqueous phase is 0.5 wt% to 1 wt%.

[0112] In some embodiments, the concentration of the magnetic starch nanoparticles in the aqueous phase is 0.5 wt%, or 0.6 wt%, or 0.7 wt%, or 0.8 wt%, or 0.9 wt%, or 1 wt%.

[0113] In some embodiments, the concentration of the magnetic starch nanoparticles in the aqueous phase is 0.5 wt%.

[0114] In some embodiments, the concentration of the magnetic starch nanoparticles in the aqueous phase is 1 wt%.

[0115] In some embodiments, the ultrasonic treatment in step (a) is ultrasonic treatment for 10-40 minutes.

[0116] In some embodiments, the ultrasonic treatment in step (a) is ultrasonic treatment for 20 minutes.

[0117] In some embodiments, the concentration of the suspension in step (a) is 0.01-0.1 wt%.

[0118] In some embodiments, the concentration of the suspension in step (a) is 0.01 wt%, or 0.02 wt%, or 0.03 wt%, or 0.04 wt%, or 0.05 wt%, or 0.06 wt%, or 0.07 wt%, or 0.08 wt%, or 0.09 wt%, or 0.1 wt%.

[0119] In some embodiments, the concentration of the suspension in step (a) is 0.05 wt%.

[0120] In some embodiments, the concentration of the gelatin aqueous solution in step (b) is 5-30 wt%.

[0121] In some embodiments, the concentration of the gelatin aqueous solution in step (b) is 5 wt%, or 6 wt%, or 7 wt%, or 8 wt%, or 9 wt%, or 10 wt%, or 11 wt%, or 12 wt%, or 13 wt%, or 14 wt%, or 15 wt%, or 20 wt%, or 25 wt%, or 30 wt%.

[0122] In some embodiments, the concentration of the gelatin aqueous solution in step (b) is 10 wt%.

[0123] In some embodiments, the volume ratio of the oil phase to the water phase in step (c) is 2:1 to 1:10.

[0124] In some embodiments, the volume ratio of the oil phase to the water phase in step (c) is 2:1, or 1:1, or 1:2, or 1:3, or 1:4, or 1:5, or 1:6, or 1:7, or 1:8, or 1:9, or 1:10.

[0125] In some embodiments, the volume ratio of the oil phase to the water phase in step (c) is 1:5.

[0126] In some embodiments, the stirring in step (c) is high-speed stirring for 20-50 minutes.

[0127] In some embodiments, the stirring in step (c) is high-speed stirring for 40 minutes.

[0128] In some implementations, the room temperature placement in step (c) is to place the item at room temperature for 1-3 days.

[0129] In some implementations, the room temperature placement in step (c) is placement at room temperature for 1 day, 2 days, or 3 days.

[0130] In some implementations, the room temperature placement in step (c) is to place the item at room temperature for 3 days.

[0131] In some embodiments, the concentration of the ethanol solution of the crosslinking agent in step (d) is 0.2-2 wt%.

[0132] In some embodiments, the concentration of the ethanol solution of the crosslinking agent in step (d) is 0.2 wt%, or 0.3 wt%, or 0.4 wt%, 0.5 wt%, or 0.6 wt%, or 0.7 wt%, or 0.8 wt%, or 0.9 wt%, or 1 wt%, or 1.1 wt%, or 1.2 wt%, or 1.3 wt%, or 1.4 wt%, or 1.5 wt%, or 1.6 wt%, or 1.7 wt%, or 1.8 wt%, or 1.9 wt%, or 2 wt%.

[0133] In some embodiments, the concentration of the ethanol solution of the crosslinking agent in step (d) is 0.5-1 wt%.

[0134] In some embodiments, the concentration of the ethanol solution of the crosslinking agent in step (d) is 0.5 wt%, or 0.6 wt%, or 0.7 wt%, or 0.8 wt%, or 0.9 wt%, or 1 wt%.

[0135] In some embodiments, the concentration of the ethanol solution of the crosslinking agent in step (d) is 0.5 wt%.

[0136] In some embodiments, the concentration of the ethanol solution of the crosslinking agent in step (d) is 1 wt%.

[0137] In some implementations, the room temperature maintenance described in step (d) is to maintain the room temperature for 2-8 hours.

[0138] In some implementations, the room temperature maintenance described in step (d) is to maintain the room temperature for 4-6 hours.

[0139] In some implementations, the room temperature maintenance in step (d) is to maintain the room temperature for 4 hours, 5 hours, or 6 hours.

[0140] In some embodiments, the cleaning in step (d) is performed using isopropanol.

[0141] In some implementations, the drying in step (d) is drying at room temperature.

[0142] The present invention also provides the application of the anti-adhesion membrane or the preparation method thereon in the preparation of tissue and organ repair products for humans or animals.

[0143] Comparative Example 1: Preparation of ordinary anti-adhesion film

[0144] The specific preparation steps are as follows:

[0145] 1. Add an appropriate amount of starch nanoparticles to purified water, sonicate for 30 minutes, and prepare a nanoparticle suspension with a concentration of 0.05wt%.

[0146] 2. Add a 10 wt% gelatin aqueous solution to the nanoparticle suspension at room temperature and stir until homogeneous. The nanoparticles account for 1 wt% of the mass of the gelatin.

[0147] 3. Add liquid paraffin at a water-to-oil volume ratio of 1:5, stir at high speed for 40 minutes, then cast into a film, and leave at room temperature for 3 days to obtain an uncrosslinked film.

[0148] 4. Immerse the uncrosslinked membrane in a 0.5 wt% glutaraldehyde ethanol solution and keep it at room temperature for 5 hours. Clean the crosslinked membrane with isopropanol. After cleaning, dry the membrane at room temperature to obtain an anti-adhesion membrane with a thickness of 0.23 mm.

[0149] Example 1: Preparation of anti-adhesion film

[0150] The specific preparation steps are as follows:

[0151] 1. Weigh 14g of starch and add 20ml of distilled water to a three-necked flask. Continuously bubble nitrogen gas into the solution and slowly add 250ml of 0.5M ferrous chloride solution while stirring continuously at 1000rpm for 2 hours.

[0152] 2. After the reaction is complete, the solution is centrifuged twice at 3500 r / min. The precipitate is then added to 250 ml of distilled water to suspend it. Then, 0.5 M sodium hydroxide solution is added dropwise until the pH reaches 10.

[0153] 3. When the solution color changes from brownish-yellow to brownish-green, place the solution in a 65℃ water bath, and then add 20% hydrogen peroxide solution dropwise. When the last drop is added, the solution turns brownish-red. Continue stirring for 60 minutes.

[0154] 4. After the reaction is complete, allow the mixture to cool to room temperature, neutralize it with glacial acetic acid, centrifuge it twice at 3500 r / min, wash the precipitate three times with 80% alcohol solution, and dry the obtained sample in a 45℃ oven to obtain magnetic starch nanoparticles.

[0155] 5. Add an appropriate amount of magnetic starch nanoparticles to purified water, sonicate for 20 minutes, and prepare a suspension with a concentration of 0.05wt%.

[0156] 6. Add 10 wt% gelatin aqueous solution to the nanoparticle suspension at room temperature and stir until homogeneous. The nanoparticles account for 0.5 wt% of the mass of the gelatin.

[0157] 7. Add liquid paraffin at a water-to-oil volume ratio of 1:5, stir at high speed for 40 minutes, then cast into a film, and then place at room temperature for 3 days to obtain an uncrosslinked film.

[0158] 8. Immerse the uncrosslinked membrane in a 0.5wt% glutaraldehyde ethanol solution and keep it at room temperature for 4 hours. Clean the crosslinked membrane with isopropanol. After cleaning, dry the membrane at room temperature to obtain an anti-adhesion membrane with a thickness of 0.22 mm.

[0159] Example 2: Preparation of anti-adhesion film

[0160] The specific preparation steps are as follows:

[0161] 1. Weigh 14g of starch and add 20ml of distilled water to a three-necked flask. Continuously bubble nitrogen gas into the solution and slowly add 250ml of 0.5M ferrous chloride solution while stirring continuously at 1000rpm for 2 hours.

[0162] 2. After the reaction is complete, the solution is centrifuged twice at 3500 r / min. The precipitate is then added to 250 ml of distilled water to suspend it. Then, 0.5 M sodium hydroxide solution is added dropwise until the pH reaches 10.

[0163] 3. When the solution color changes from brownish-yellow to brownish-green, place the solution in a 65℃ water bath, and then add 20% hydrogen peroxide solution dropwise. When the last drop is added, the solution turns brownish-red. Continue stirring for 60 minutes.

[0164] 4. After the reaction is complete, allow the mixture to cool to room temperature, neutralize it with glacial acetic acid, centrifuge it twice at 3500 r / min, wash the precipitate three times with 80% alcohol solution, and dry the obtained sample in a 45℃ oven to obtain magnetic starch nanoparticles.

[0165] 5. Add an appropriate amount of magnetic starch nanoparticles to purified water, sonicate for 20 minutes, and prepare a suspension with a concentration of 0.05wt%.

[0166] 6. Add a 10 wt% gelatin aqueous solution to the nanoparticle suspension at room temperature and stir until homogeneous. The nanoparticles account for 1 wt% of the mass of the gelatin.

[0167] 7. Add liquid paraffin at a water-to-oil volume ratio of 1:5, stir at high speed for 40 minutes, then cast into a film, and then place at room temperature for 3 days to obtain an uncrosslinked film.

[0168] 8. Immerse the uncrosslinked membrane in a 1 wt% glutaraldehyde ethanol solution and keep it at room temperature for 6 hours. Clean the crosslinked membrane with isopropanol. After cleaning, dry the membrane at room temperature to obtain an anti-adhesion membrane with a thickness of 0.26 mm.

[0169] Example 3: Preparation of anti-adhesion film

[0170] The specific preparation steps are as follows:

[0171] 1. Weigh 14g of starch and add 20ml of distilled water to a three-necked flask. Continuously bubble nitrogen gas into the solution and slowly add 250ml of 0.5M ferrous chloride solution while stirring continuously at 1000rpm for 2 hours.

[0172] 2. After the reaction is complete, the solution is centrifuged twice at 3500 r / min. The precipitate is then added to 250 ml of distilled water to suspend it. Then, 0.5 M sodium hydroxide solution is added dropwise until the pH reaches 10.

[0173] 3. When the solution color changes from brownish-yellow to brownish-green, place the solution in a 65℃ water bath, and then add 20% hydrogen peroxide solution dropwise. When the last drop is added, the solution turns brownish-red. Continue stirring for 60 minutes.

[0174] 4. After the reaction is complete, allow the mixture to cool to room temperature, neutralize it with glacial acetic acid, centrifuge it twice at 3500 r / min, wash the precipitate three times with 80% alcohol solution, and dry the obtained sample in a 45℃ oven to obtain magnetic starch nanoparticles.

[0175] 5. Add an appropriate amount of magnetic starch nanoparticles to purified water, sonicate for 20 minutes, and prepare a suspension with a concentration of 0.05wt%.

[0176] 6. Add a 10 wt% gelatin aqueous solution to the nanoparticle suspension at room temperature and stir until homogeneous. The nanoparticles account for 5 wt% of the mass of the gelatin.

[0177] 7. Add liquid paraffin at a water-to-oil volume ratio of 1:5, stir at high speed for 40 minutes, then cast into a film, and then place at room temperature for 3 days to obtain an uncrosslinked film.

[0178] 8. Immerse the uncrosslinked membrane in a 0.5 wt% glutaraldehyde ethanol solution and keep it at room temperature for 5 hours. Clean the crosslinked membrane with isopropanol. After cleaning, dry the membrane at room temperature to obtain an anti-adhesion membrane with a thickness of 0.25 mm.

[0179] Example 4: Surface morphology test

[0180] Scanning electron microscopy compares the anti-adhesion films prepared in Example 1 and Examples 1-3, and the results are as follows: Figure 1-4 As shown, the anti-adhesion films prepared in Comparative Example 1 and Examples 1-3 all have good porosity structures and uniform porous structures.

[0181] Example 5: Water Absorption Test

[0182] The water absorption of the anti-adhesion films prepared in Comparative Example 1 and Examples 1-3 was tested according to GB / T 1034-2008. The specific steps are as follows:

[0183] Take a certain amount of sample and dry it in a 50℃ oven until its mass no longer changes. Accurately weigh the sample to obtain M1. Place the dried sample in a beaker containing an appropriate amount of purified water and let it stand for about 24 hours. Remove excess surface moisture and weigh the fully expanded sample. Accurately weigh the sample and record it as M2. Finally, dry the sample again in a 50℃ oven until its mass no longer changes. Weigh the sample after drying to constant weight and record it as M3. The water absorption mass fraction is calculated using the following formula:

[0184]

[0185] The results are shown in Table 1:

[0186] Table 1: Water Absorption Rate of Anti-blocking Film

[0187] Example 1 1600±44 Example 2 1800±15 Example 3 1500±68 Comparative Example 1 1600±52

[0188] The results show that the anti-adhesion membranes prepared in Examples 1-3 and Comparative Example 1 all have a water absorption rate greater than 1500%, exhibiting extremely strong water absorption properties and broad application prospects in the field of postoperative tissue hemostasis and anti-adhesion. The emulsion stabilized by nanoparticles can effectively reduce phase separation in the system, resulting in a porous membrane with uniform pore size distribution and high porosity. It also forms numerous capillary channels, increasing the water absorption rate. However, when the content of nano-starch in the emulsion is too high, the nano-starch aggregates, affecting the pore size distribution of the porous membrane, resulting in low porosity and impacting its water absorption rate.

[0189] Example 6: Characterization of protein adsorption capacity

[0190] During wound healing, exudate flows out, containing certain protein components. An ideal anti-adhesion membrane possesses appropriate protein adsorption capacity, which facilitates timely cleaning of wound surface exudate and promotes cell growth and migration. The model protein BSA was used to characterize the anti-adhesion membranes prepared in Comparative Example 1 and Examples 1-3, examining their protein adsorption capacity. The specific steps are as follows:

[0191] Approximately 30 mg of sample was weighed and fixed in a 24-well culture plate. The sample was soaked in 75% medical alcohol for 60 min, followed by soaking in PBS buffer for 2 h. The treated sample was then immersed in a culture plate containing 0.75 mL of BSA (10 mg / mL) solution and incubated at 37°C in a shaker for 24 h. The absorbance of the BSA solution at 595 nm was measured using a spectrometer. The concentration of BSA in the solution before and after adsorption was calculated from the standard curve of concentration-absorbance at the same wavelength. The results are shown in Table 2.

[0192] Table 2: Protein Adsorption Amount of Anti-Adhesion Membrane

[0193] Example 1 113±0.44 Example 2 150±0.15 Example 3 124±0.68 Comparative Example 1 85±0.23

[0194] The results showed that the anti-adhesion membranes prepared in Examples 1-3 had a significantly higher adsorption capacity for BSA compared to Comparative Example 1. The gelatin porous membranes prepared in Examples 1-3 contained magnetic starch nanoparticles. These magnetic particles could adsorb proteins on the surface, thus adsorbing exudate during wound healing. Under certain conditions, the higher the content of magnetic particles, the stronger the protein adsorption capacity. However, when the content of magnetic particles exceeded a certain proportion, it affected the pore size distribution of the porous membrane, thereby reducing its protein adsorption capacity. The porous membranes prepared in Examples 1-3 have broad application prospects in the field of postoperative tissue hemostasis and anti-adhesion.

[0195] Example 7: Characterization of anti-adhesion performance

[0196] Test Method: The experimental animal model used was a rabbit abdominal uterine horn adhesion model to simulate adhesions caused by gynecological surgery. After anesthesia, a 3-4 cm longitudinal incision was made along the midline of the lower abdomen to open the peritoneum. The uterine horn was then identified using a tool, and the serosal layer of the uterine horn was rubbed with sandpaper until obvious pinpoint bleeding was observed. Control group: The wound was treated with only physiological saline; Experimental group: The uterine horn wound was covered with a 1 cm × 1 cm anti-adhesion membrane as described in Example 2 above, and fixed with sutures. After model completion, the abdominal skin and muscles were sutured, and the rabbits were euthanized after 7 days of normal feeding. The abdominal cavity was then opened to examine the adhesions.

[0197] The results of the control group experiment are as follows Figure 5 As shown, the control group rabbits had severe adhesions in their abdominal cavity and uterine horn, while the experimental group showed the following results. Figure 6 As shown, no adhesions occurred between the abdominal cavity and uterine horn of the rabbits using the anti-adhesion membrane of Example 2, and the wound healed well. The gelatin anti-adhesion membrane prepared by the emulsion method provided by this invention can effectively prevent postoperative tissue adhesions, establish a moist healing environment, and thus accelerate wound healing.

[0198] It should be understood that the above embodiments are exemplary and are not intended to encompass all possible implementations included in the claims. Various modifications and changes can be made to the above embodiments without departing from the scope of this disclosure. Similarly, the various technical features of the above embodiments can be arbitrarily combined to form other embodiments of the present invention that may not be explicitly described. Therefore, the above embodiments only illustrate several implementations of the present invention and do not limit the scope of protection of this patent.

Claims

1. A method for preparing an anti-adhesion film, characterized in that, The method includes: (a) Add magnetic starch nanoparticles to water, sonicate, and prepare a suspension; (b) Add gelatin aqueous solution to the suspension prepared in step (a), stir until homogeneous, and obtain the aqueous phase; (c) Add the oil phase to the aqueous phase prepared in step (b), stir and cast into a film, and after standing at room temperature, obtain an uncrosslinked film; (d) Immerse the uncrosslinked membrane in an ethanol solution of a crosslinking agent, keep at room temperature, and then wash and dry to obtain the anti-adhesion membrane; The magnetic starch nanoparticles constitute 0.1wt%-5wt% of the gelatin by mass. The concentration of the suspension in step (a) is 0.01-0.1 wt%; The concentration of the gelatin aqueous solution in step (b) is 5-30 wt%; The volume ratio of the oil phase to the water phase in step (c) is 2:1 to 1:10; The preparation method of the magnetic starch nanoparticles includes: adding an aqueous hydroxide solution to a solution containing starch and metal ions, then adding an oxidant dropwise, neutralizing, separating, washing, and drying; The metal ion is ferrous chloride.

2. The preparation method according to claim 1, characterized in that, The preparation method of the magnetic starch nanoparticles includes the following steps: (1) Dissolve starch in water, continuously pass in inert gas, and then slowly add a solution containing metal ions while stirring; (2) After the reaction in step (1) is completed, centrifuge the precipitate, suspend it in water, and add an aqueous hydroxide solution to adjust the pH. (3) When the solution color changes, add oxidant dropwise in a water bath. Stop adding dropwise and stir after the solution changes color. (4) Cool the solution to room temperature and adjust the pH, centrifuge, wash the precipitate, and dry to obtain the magnetic starch nanoparticles.

3. The preparation method according to claim 2, characterized in that, The starch mentioned in step (1) is nano-sized starch; And / or, the inert gas in step (1) is nitrogen; And / or, the aqueous hydroxide solution in step (2) is a sodium hydroxide solution; And / or, the pH adjustment described in step (2) is to adjust the pH to 10-12; And / or, the oxidant in step (3) is a hydrogen peroxide solution; And / or, the pH adjustment described in step (4) is to adjust the pH to neutral.

4. The preparation method according to claim 2, characterized in that, The starch mentioned in step (1) is a modified nano-sized starch with a particle size of 1-1000 nm.

5. The preparation method according to claim 1, characterized in that, The raw materials for preparing the anti-adhesion film also include gelatin and / or oil phase and / or crosslinking agent and / or solvent; And / or, the oil phase is selected from one or more of liquid paraffin, vegetable oil, and ethyl acetate; And / or, the crosslinking agent is selected from one or more of formaldehyde, glyoxal, malondialdehyde, succinaldehyde, glutaraldehyde, genipin, and 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide (EDC); And / or, the solvent is selected from one or more of water, methanol, ethanol, isopropanol, n-butanol, acetone, acetonitrile, and tetrahydrofuran.

6. The preparation method according to claim 1, characterized in that, The oil phase is liquid paraffin; And / or, the crosslinking agent is glyoxal and / or glutaraldehyde; And / or, the solvent is water and / or ethanol.

7. The preparation method according to claim 1, characterized in that, The thickness of the anti-adhesion film is 0.1-2 mm.

8. The preparation method according to claim 1, characterized in that, The thickness of the anti-adhesion film is 0.1-0.5 mm.

9. The preparation method according to claim 1, characterized in that, The thickness of the anti-adhesion film is 0.2-0.3 mm.

10. The preparation method according to claim 1, characterized in that, The magnetic starch nanoparticles account for 0.5wt%-1wt% of the gelatin by mass.

11. The preparation method according to claim 1, characterized in that, The concentration of the suspension in step (a) is 0.05 wt%. And / or, the concentration of the gelatin aqueous solution in step (b) is 10 wt%; And / or, the volume ratio of the oil phase to the water phase in step (c) is 1:5; And / or, the concentration of the ethanol solution of the crosslinking agent in step (d) is 0.2-2 wt%.

12. The preparation method according to claim 1, characterized in that, The concentration of the ethanol solution of the crosslinking agent is 0.5-1 wt%.

13. An anti-adhesion film prepared by the method according to any one of claims 1-12.

14. The use of the anti-adhesion membrane according to claim 13 or the preparation method according to any one of claims 1-12 in the preparation of tissue and organ repair products for humans or animals.

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