Stretch self-crimping wet adhesive patch for repairing esophageal fistula and method of making same

Abstract

The present application relates to the technical field of biomaterials, and particularly relates to a stretch self-coiling wet adhesive patch for repairing esophageal fistula and a preparation method thereof, the adhesive patch comprising an elastic layer hydrogel and a constraint layer hydrogel; the elastic layer hydrogel is a high-crosslinking-density low-modulus hydrogel; and the constraint layer hydrogel is a low-crosslinking-density high-modulus hydrogel. The present application constructs a strong-adhesion biological adaptive interface based on a polysaccharide or polypeptide double-modulus layer integration, the elastic layer has high crosslinking density, realizes elastic deformation and strong adhesion, the constraint layer has low crosslinking density and plastic deformation, and after stretching, due to the large residual strain, the constraint layer is curled to the elastic layer due to the difference in deformation recovery. The patch can be self-coiled in a stretch-activated manner to wrap the esophagus under dynamic wet physiological conditions and quickly adhere, realize strong adhesion, self-adaptive conformation and stable interface adaptation with the high-curvature esophageal tissue of the dynamic wet surface, and effectively seal and repair the fistula.

Description

Technical Field

[0001] This invention relates to the field of biomaterials technology, specifically to a stretchable self-coiling wet-adhesive patch for repairing esophageal fistulas and its preparation method. Background Technology

[0002] Esophageal fistula refers to a pathological passage formed between the esophagus and adjacent organs due to various causes, which the esophagus itself cannot repair. Clinical treatment of esophageal fistula typically requires effective sealing of the fistula opening, strong integration with the esophagus, and avoidance of complications. Currently, treatment mainly relies on surgical suturing and esophageal stent placement. However, esophageal surgery is complex, involves various procedures, and presents a significant challenge to surgeons. Complications such as stent slippage or displacement, stent expansion, esophageal restenosis, and food deposition remain difficult to resolve clinically. These complications not only hinder fistula repair but also lead to pleural infections, requiring repeated surgeries, severely impacting patients' quality of life, and even endangering their lives.

[0003] Hydrogel tissue adhesives have shown promising potential in various wound repair applications due to their excellent hydrophilicity, biocompatibility, biodegradability, strong interfacial and intrinsic adhesion, and ease of application. However, existing hydrogel tissue adhesives are mostly liquid adhesives or planar patches. Liquid adhesives often fail to achieve sufficient contact with wet tissue and may flow to undesirable areas. Planar patches, especially for the high surface curvature of esophageal tissue, are prone to curling and rebounding after application, making adhesion difficult, resulting in detachment or prolonged adhesion time. Furthermore, they may not conform to the esophagus, restricting its physiological activity. Patches activated by external stimuli such as water or light exhibit slow responses, and uneven application of stimulation during clinical operation can lead to uncontrollable deformation, all posing challenges to clinical practice. Therefore, existing hydrogel tissue adhesives are insufficient for effective sealing and repair of esophageal fistulas, necessitating the development of a new esophageal fistula patch to address these issues. Summary of the Invention

[0004] To address the problems existing in the prior art, the present invention provides a stretchable self-rolling wet adhesive patch for repairing esophageal fistulas and its preparation method, aiming to solve the problems of rebound after rolling and application, resulting in application difficulties, difficulty in forming effective adhesion and falling off or prolonging the adhesion time, inability to conform to the esophagus and thus restricting esophageal physiological activities, and inconvenience for clinical operation.

[0005] This invention is achieved through the following technical solution:

[0006] A method for preparing a stretchable self-coiling wet-adhesive patch for repairing esophageal fistulas includes the following steps:

[0007] S1, dissolve the first type of hydrogel, the second type of hydrogel, acrylic acid, and N-hydroxysuccinimide acrylate in an appropriate amount of deionized water, heat in a water bath, and after the system is mixed evenly, add a photoinitiator, and continue stirring evenly in the dark to obtain a prepolymer solution; wherein, the first type of hydrogel is a polysaccharide hydrogel or a polypeptide hydrogel, and the second type of hydrogel is one or a mixture of photocrosslinkable methacryloyl polysaccharide hydrogel and polypeptide hydrogel.

[0008] S2, filter and sterilize the prepolymer solution, transfer it to a self-made mold, and crosslink it under ultraviolet light;

[0009] S3. After drying the cross-linked patch, encapsulate it and freeze it to obtain a stretchable self-rolling wet-adhesive patch that can repair esophageal fistulas.

[0010] Preferably, in S1, the polysaccharide hydrogel is one or a mixture of chitosan, sodium alginate, hyaluronic acid, dextran, and cellulose;

[0011] Photocrosslinked polysaccharide hydrogels are hydrogels modified by methacrylation of polysaccharide hydrogels;

[0012] Peptide hydrogels are one or a mixture of gelatin, fibroin, peptides, peptide-based polymers, or protein hydrogels.

[0013] Photocrosslinked polypeptide hydrogels are hydrogels modified by methacrylation of polypeptide hydrogels;

[0014] The water bath heating temperature is 50–60℃;

[0015] The photoinitiator is α-ketoglutaric acid or I2959.

[0016] Preferably, in S1, when the first type of hydrogel is a polysaccharide hydrogel, its mass percentage in the prepolymer solution is 10 wt%.

[0017] When the first type of hydrogel is a polypeptide hydrogel, its mass percentage is 2wt%.

[0018] Acrylic acid comprises 30wt% to 35wt% by weight;

[0019] The mass percentage of N-hydroxysuccinimide acrylate is 0.1 wt%.

[0020] The second type of hydrogel has a mass percentage of 1 wt%.

[0021] Deionized water mass percentage: 50wt%-60wt%;

[0022] The photoinitiator has a mass percentage of 0.02wt%-0.05wt%.

[0023] Preferably, in S2, the filtration and sterilization method is filtration using a 0.02μm sterilization filter.

[0024] Preferably, in S2, the mold is a polytetrafluoroethylene non-stick mold.

[0025] Preferably, in S2, the wavelength of the ultraviolet light is 280nm–365nm, and the power is 100mW / cm². 2 The distance between the light source and the mold is 15-20cm.

[0026] Preferably, in step S3, the drying temperature is 40–50°C and the drying time is 10 min.

[0027] Preferably, in S3, the packaging process uses a sterilized bag for heat sealing.

[0028] Preferably, in S3, the temperature for frozen storage is -20 to -40°C.

[0029] An adhesive patch prepared by the aforementioned method for preparing a stretchable self-coiling wet adhesive patch for repairing esophageal fistulas includes an elastic layer hydrogel and a restraint layer hydrogel; the elastic layer hydrogel is a highly cross-linked, low-modulus hydrogel; and the restraint layer hydrogel is a low-cross-linked, high-modulus hydrogel.

[0030] Compared with the prior art, the present invention has the following beneficial effects:

[0031] This invention discloses a method for preparing a stretchable self-curling wet-adhesive patch for repairing esophageal fistulas. The method constructs a strong adhesive biocompatible interface based on a bimodal layer of polysaccharide or polypeptide hydrogel. The elastic layer has a high cross-linking density, achieving both elastic deformation and strong adhesion, while the constraint layer has a low cross-linking density and undergoes plastic deformation. After stretching, due to the large residual strain, the patch exhibits a difference in deformation recovery compared to the elastic layer, causing it to curl towards the elastic layer. The patch can self-curl and wrap around the dynamically moistened esophagus under physiological conditions through stretching activation, achieving rapid adhesion and sutureless, strong adhesion, adaptive conformal, and stable interface adaptation with the high curvature of the dynamically moist esophageal tissue, effectively sealing and repairing the fistula.

[0032] Before stretching, the hydrogel patch exhibits a planar structure. It is composed of hydrogels of the same component, with differences in cross-linking degree arising from oxygen inhibition. The elastic layer is 40–50 μm thick, while the constraint layer is 200 μm thick. Compared to the elastic layer, the constraint layer has a lower cross-linking density and higher crystallinity. The crystallinity-controlled driving domain can fix the deformation. The system lacks sufficient cross-linked network structures to provide entropic elasticity to generate deformation recovery stress, thus exhibiting larger residual strain and better plasticity. Before stretching, the elastic layer has lower crystallinity and a higher cross-linking density, resulting in elastic deformation after the tension is released. Due to its larger residual strain, the constraint layer curls towards the elastic layer due to the difference in deformation recovery. However, under stress, the molecular chains in the elastic layer are fully extended and reassembled. After stretching, the crystallinity increases, and the elasticity transforms into plasticity, resulting in plastic deformation and ensuring the overall curling stability of the patch.

[0033] The acrylic component in the hydrogel patch contains a large number of carboxyl groups. After drying, when the patch comes into contact with wet tissue, it can dry the water at the tissue interface, form hydrogen bonds and electrostatic interactions with the tissue, and achieve instantaneous physical adhesion. After copolymerization with acrylic acid, the aldehyde groups on the succinimide groups of the N-hydroxysuccinimide acrylate can form covalent bonds with the amino groups exposed on the tissue surface, ensuring stable chemical adhesion.

[0034] After the patch is stretched, micron-sized wrinkles are generated on the surface of the elastic layer perpendicular to the direction of tension. The stretching and release process has a certain deformation margin, which allows the patch to adapt to the contraction and relaxation deformation of the esophagus. It not only has a certain closing effect on the esophageal fistula, but also enhances cell adhesion at the microscopic level, which promotes wound healing.

[0035] The patch has lower cell adhesion in the constraint layer due to its lower degree of cross-linking, resulting in fewer exposed free carboxyl and amide groups compared to the elastic layer. This helps prevent the non-adhesive layer from adhering to other organs near the esophagus. The elastic layer, before stretching, has lower crystallinity; after stretching and activation, it exposes a large number of carboxyl and amide groups, ensuring strong and stable adhesion to the tissue.

[0036] The present invention discloses a stretchable self-curling wet-adhesive patch and its preparation method. By utilizing the oxygen inhibition effect, the patch of the same material forms a bilayer hydrogel with different degrees of crosslinking. The elastic layer and the constraint layer are prepared as an integral unit, avoiding the large interfacial stress caused by traditional bilayer bonding preparation. Therefore, it can avoid bilayer peeling caused by dynamic stretching, which would lead to curling failure.

[0037] The present invention has a simple structure, and the entire system adopts a one-pot reaction process under aqueous medium conditions. The preparation process is easy to implement. Compared with most other hydrogel patches, it is easier to achieve clinical use in terms of both materials and preparation, and the overall cost is lower.

[0038] This invention's patch not only ensures the formation of micron-level wrinkles perpendicular to the direction of tension on the surface of the elastic layer after stretching, but also, to a certain extent, converts the residual strain of the constraint layer into plastic deformation after the tension is released. This allows the patch's curled shape to maintain elasticity, making it easier to adapt to the contraction and relaxation deformation of the esophagus. It not only has a certain closing effect on esophageal fistulas but also enhances cell adhesion at the microscopic level, promoting wound healing. Biological experiments on rabbit esophageal fistula repair were conducted using this invention's stretchable self-curling wet-adhesive patch, including esophageal detachment, fistula creation, repair, and postoperative observation. The experiments showed that the patch has good biocompatibility and excellent sealing and repair capabilities for esophageal fistulas. Therefore, this invention has significant guiding significance and reference value for the design and preparation of patches for treating esophageal fistulas, solving the problems of existing patches that easily generate internal rebound stress after curling, causing application difficulties, difficulty in forming effective adhesion leading to detachment or prolonged adhesion time, inability to conform to the esophagus, restriction of esophageal physiological activity causing esophageal restenosis, and difficulty in clinical operation. Attached Figure Description

[0039] Figure 1 This is a schematic flowchart of the preparation method of the stretchable self-curling wet adhesive patch of the present invention;

[0040] Figure 2 This is a schematic diagram of mold a for the stretchable self-curling wet adhesive patch of the present invention;

[0041] Figure 3 This is a schematic diagram of mold b for the stretchable self-curling wet adhesive patch of the present invention;

[0042] Figure 4 This is a cross-sectional scanning electron microscope (SEM) schematic diagram of the stretch self-curling wet adhesive patch prepared in Example 1.

[0043] Figure 5 These are surface morphology images of the elastic layer of the stretch self-curling wet-adhesive patch prepared in Example 1 before and after stretching.

[0044] Figure 6 The image shows the infrared spectra of the stretchable self-curling wet-adhesive patch prepared in Example 1 before and after stretching.

[0045] Figure 7 These are XRD characterization images of the stretchable self-curling wet-adhesive patch prepared in Example 1 before and after stretching.

[0046] Figure 8 This is a schematic diagram of the tensile self-curling wet-adhesive patch prepared in Example 1, showing its tensile self-curling mechanical analysis. Detailed Implementation

[0047] The present invention will be further described in detail below with reference to specific embodiments. These descriptions are for explanation purposes only and are not intended to limit the scope of the invention.

[0048] This invention discloses a method for preparing a stretchable self-coiling wet-adhesive patch for repairing esophageal fistulas, referring to... Figure 1 A method for preparing a stretchable self-coiling wet-adhesive patch for repairing esophageal fistulas includes the following steps:

[0049] S1, dissolve the first type of hydrogel, the second type of hydrogel, acrylic acid, and N-hydroxysuccinimide acrylate in an appropriate amount of deionized water, heat in a water bath, add the photoinitiator after the system is mixed evenly, and continue stirring evenly in the dark to obtain the prepolymer solution.

[0050] Among them, the first type of hydrogel is a polysaccharide hydrogel or a polypeptide hydrogel. The polysaccharide hydrogel is one or a mixture of chitosan, sodium alginate, hyaluronic acid, dextran, and cellulose. The polypeptide hydrogel is one or a mixture of gelatin, fibroin, polypeptides, and peptide-based polymers, etc., or polypeptide or protein hydrogels.

[0051] The second type of hydrogel is one or a mixture of photocrosslinkable methacrylamide polysaccharide hydrogels and polypeptide hydrogels; photocrosslinkable polysaccharide hydrogels are hydrogels modified by methacrylamide in accordance with the polysaccharide hydrogels; crosslinked polypeptide hydrogels are hydrogels modified by methacrylamide in accordance with the polypeptide hydrogels.

[0052] The photoinitiator is α-ketoglutaric acid or I2959.

[0053] In the prepolymer solution, when the first type of hydrogel is a polysaccharide hydrogel, the mass percentage is 10 wt%.

[0054] When the first type of hydrogel is a polypeptide hydrogel, the mass percentage is 2wt%.

[0055] Acrylic acid comprises 30wt% to 35wt% by weight;

[0056] The mass percentage of N-hydroxysuccinimide acrylate is 0.1 wt%.

[0057] The second type of hydrogel has a mass percentage of 1 wt%.

[0058] Deionized water mass percentage: 50wt%-60wt%;

[0059] The photoinitiator has a mass percentage of 0.02wt%-0.05wt%.

[0060] S2, the prepolymer solution was filtered and sterilized using a 0.02μm sterilization filter, transferred to a self-made polytetrafluoroethylene non-stick mold, and then subjected to crosslinking under ultraviolet light with a wavelength of 280nm-365nm at a power of 100mW / cm². 2 The distance between the light source and the mold is 15-20cm.

[0061] S3. After drying the cross-linked patch at 40-50℃ for 10 minutes, it is then heat-sealed in a sterilized bag and frozen at -20℃ to obtain a stretchable self-rolling wet adhesive patch that can repair esophageal fistula.

[0062] The present invention also discloses an adhesive patch prepared by a method for preparing a stretchable self-coiling wet adhesive patch for repairing esophageal fistula, comprising an elastic layer hydrogel and a restraint layer hydrogel; the elastic layer hydrogel is a highly cross-linked low-modulus hydrogel; and the restraint layer hydrogel is a low-cross-linked high-modulus hydrogel.

[0063] Example 1

[0064] S1. Take 1g of gelatin, 3g of acrylic acid, 0.1g of N-hydroxysuccinimide acrylate, 0.01g of methacrylamide gelatin (GelMA), 0.002g of photoinitiator α-ketoglutaric acid or 0.005g of I2959, dissolve them in 5.8g of deionized water, heat in a 50℃ water bath in the dark for 10min, and gently shake to form a uniform prepolymer solution.

[0065] S2. Draw 10 mL of prepolymer solution with a sterile syringe, attach a 0.22 μm PES water-based sterile filter to the tip of the syringe, filter it, transfer it to a self-made polytetrafluoroethylene mold, remove bubbles with a capillary tube, let it stand, and then perform ultraviolet crosslinking for 30 min.

[0066] There are two designs for polytetrafluoroethylene (PTFE) molds. Figure 2 The middle mold is designed as a parallelogram. Figure 3 The intermediate mold is rectangular in design. The overall dimensions of the PTFE mold are 100mm × 100mm × 10mm, and the depth of its patch groove is 1mm. All four corners of the patch in both molds are rounded. Figure 2 The two pairs of opposite sides of the parallelogram have side lengths of 8.67mm and 8.16mm respectively, and the chamfer radius is 4mm. The parallelogram design facilitates the spiral curling of the patch, avoids patch butt joints, and further improves its adaptability during esophageal contraction and relaxation. It can prevent food impaction caused by inconsistent contraction and relaxation between the patch and the esophagus during fistula healing. Figure 3 The rectangular patches have opposite sides of 18mm and 15mm respectively, and the chamfer radius is 4mm. Both designs have chamfered corners to avoid stress concentration between the patch and the esophagus.

[0067] S3. The mold containing the hydrogel patch is dried in a sterile room at 50°C for 10 minutes. Subsequently, the hydrogel patch is peeled off from the mold, sealed in a sterile bag, and a stretchable, self-curling double-layer hydrogel patch is obtained and stored in a freezer at -20°C.

[0068] Figure 4 This is a cross-sectional scanning electron microscope (SEM) schematic diagram of the stretchable self-curling wet-adhesive patch prepared in Example 1. Analysis shows that the cross-section compares the morphology of the elastic layer and the constraint layer, indicating that the elastic layer has a denser structure than the bottom constraint layer. The two layers are fabricated as a single unit with a natural interface transition, avoiding the large interfacial stress caused by traditional double-layer bonding. Therefore, it avoids double-layer delamination due to dynamic stretching, which could lead to curling failure.

[0069] Figure 5 The images show the surface morphology of the elastic layer of the stretchable self-curling wet adhesive patch prepared in Example 1 before and after stretching. After stretching, micron-sized wrinkles perpendicular to the direction of tension are generated on the surface of the elastic layer. After the tension is released, the residual strain of the constraint layer is converted into plastic deformation to a certain extent, allowing the patch to maintain its curled shape elastically. This makes it easier to adapt to the contraction and relaxation deformation of the esophagus, not only providing a certain closing effect on the esophageal fistula, but also enhancing cell adhesion at the microscopic level, thus promoting wound healing. This has important guiding significance and reference value for the design and preparation of patches for treating esophageal fistulas, solving the significant limitations of existing patches, such as rebound after curling, making application difficult, difficulty in forming effective adhesion leading to detachment or prolonged adhesion time, inability to conform to the esophagus, restriction of esophageal physiological activity causing esophageal restenosis, and difficulty in clinical operation.

[0070] Figure 6 The images show the infrared spectra of the stretchable self-curling wet adhesive patch prepared in Example 1 before and after stretching. They indicate that the restraint layer of the patch has a lower degree of cross-linking, resulting in fewer exposed free carboxyl and amino groups compared to the stretched elastic layer. This leads to lower cell adhesion and, to some extent, prevents the non-adhesive layer from adhering to other organs near the esophagus. The elastic layer, before stretching, has almost no free carboxyl and amino groups, allowing it to be freely positioned at the esophageal fistula before adhesion without instantaneous adhesion due to misplacement, thus avoiding peeling and further damage to the esophagus. After positioning and stretching, the elastic layer exposes a large number of carboxyl and amino groups, ensuring strong and stable adhesion to the tissue.

[0071] Figure 7These are XRD characterization images of the stretch-self-curling wet-adhesive patch prepared in Example 1 before and after stretching. The images show that the restraining layer of the patch has a lower cross-linking density and higher crystallinity compared to the elastic layer. The deformation can be fixed by the crystallization-controlled driving domain. The system lacks sufficient cross-linked network structures to provide entropic elasticity to generate deformation recovery stress, thus exhibiting larger residual strain and better plasticity. Before stretching, the elastic layer has lower crystallinity and higher cross-linking density, resulting in elastic deformation. Due to the larger residual strain, the restraining layer curls towards the elastic layer due to the difference in deformation recovery compared to the elastic layer. However, under stress, the molecular chains of the elastic layer are fully extended and reassembled. After stretching, not only do new crystal diffraction signals appear, but the crystallinity also increases, and the elasticity transforms into plasticity, producing plastic deformation and ensuring the overall curling stability of the patch.

[0072] Figure 8 This is a schematic diagram illustrating the tensile self-curling wet-adhesive patch prepared in Example 1. Based on the above analysis, the patch's tensile self-curling behavior is due to the mismatch in deformation recovery between the elastic layer and the constraint layer. After stretching, the constraint layer exhibits larger residual strain and better plasticity, while the elastic layer curls towards the elastic layer due to the difference in deformation recovery stress. The key factor in the patch's surface wrinkle morphology is the difference in modulus between the elastic layer and the constraint layer. Through tensile stimulation, the constraint layer applies a certain compressive strain to the elastic layer, causing the surface of the elastic layer to become unstable after release, thus producing a wrinkle morphology.

[0073] Example 2

[0074] S1, take 0.1g chitosan, 3g acrylic acid, 0.1g N-hydroxysuccinimide acrylate and 0.01g methacrylated chitosan (CSMA), 0.002g photoinitiator α-ketoglutarate or 0.005g I2959, dissolve in 6.8g deionized water, heat in a 50℃ water bath in the dark for 10min, and gently shake to form a uniform prepolymer solution.

[0075] S2. Draw 10 mL of prepolymer solution with a sterile syringe, attach a 0.22 μm PES water-based sterile filter to the tip of the syringe, filter it, transfer it to a self-made polytetrafluoroethylene mold, remove bubbles with a capillary tube, let it stand, and then perform ultraviolet crosslinking for 30 min.

[0076] S3. The mold containing the hydrogel patch is dried in a sterile room at 50°C for 10 minutes. Subsequently, the hydrogel patch is peeled off from the mold, sealed in a sterile bag, and a stretchable, self-curling double-layer hydrogel patch is obtained and stored in a freezer at -20°C.

[0077] The above description is merely a preferred embodiment of the present invention and is not intended to limit the technical solution of the present invention in any way. Those skilled in the art should understand that, without departing from the spirit and principles of the present invention, the technical solution can be modified and replaced in several simple ways, and these modifications and replacements are all within the scope of protection covered by the claims.

Claims

1. A method for preparing a stretchable self-coiling wet-adhesive patch for repairing esophageal fistulas, characterized in that, Includes the following steps: S1, dissolve the first type of hydrogel, the second type of hydrogel, acrylic acid, and N-hydroxysuccinimide acrylate in an appropriate amount of deionized water, heat in a water bath, and after the system is mixed evenly, add a photoinitiator, and continue stirring evenly in the dark to obtain a prepolymer solution; wherein, the first type of hydrogel is a polysaccharide hydrogel or a polypeptide hydrogel, and the second type of hydrogel is one or a mixture of photocrosslinkable methacryloyl polysaccharide hydrogel and polypeptide hydrogel. Polysaccharide hydrogels are one or a mixture of chitosan, sodium alginate, hyaluronic acid, dextran, and cellulose; Photocrosslinked polysaccharide hydrogels are hydrogels modified by methacrylation of polysaccharide hydrogels; Peptide hydrogels are one or a mixture of gelatin, fibroin, peptides, peptide-based polymers, or protein hydrogels. Photocrosslinked polypeptide hydrogels are hydrogels modified by methacrylation of polypeptide hydrogels; The water bath heating temperature is 50~60℃; The photoinitiator is α-ketoglutaric acid or I2959; In the prepolymer solution, when the first type of hydrogel is a polysaccharide hydrogel, the mass percentage of the first type of hydrogel is 2 wt%. When the first type of hydrogel is a polypeptide hydrogel, the mass percentage of the first type of hydrogel is 10 wt%. Acrylic acid content is 30wt%~35wt% by mass. The mass percentage of N-hydroxysuccinimide acrylate is 0.1 wt%. The second type of hydrogel has a mass percentage of 1 wt%; Deionized water mass percentage 50wt%-60wt%; The photoinitiator has a mass percentage of 0.02wt%-0.05wt%; S2, filter and sterilize the prepolymer solution, transfer it to a self-made mold, and crosslink it under ultraviolet light; S3. After drying the cross-linked patch, encapsulate it and freeze it to obtain a stretchable self-rolling wet adhesive patch that can repair esophageal fistula. The adhesive patch comprises an elastic layer hydrogel and a constraint layer hydrogel; the elastic layer hydrogel is a highly cross-linked, low-modulus hydrogel; and the constraint layer hydrogel is a low-cross-linked, high-modulus hydrogel.

2. The method for preparing a stretchable self-coiling wet-adhesive patch for repairing esophageal fistulas according to claim 1, characterized in that, In S2, the filtration and sterilization method is filtration using a 0.02μm sterilization filter.

3. The method for preparing a stretchable self-coiling wet-adhesive patch for repairing esophageal fistulas according to claim 1, characterized in that, In S2, the mold is a polytetrafluoroethylene non-stick mold.

4. The method for preparing a stretchable self-coiling wet-adhesive patch for repairing esophageal fistulas according to claim 1, characterized in that, In S2, the wavelength of ultraviolet light is 280nm~365nm, and the power is 100mW / cm². 2 The distance between the light source and the mold is 15~20cm.

5. The method for preparing a stretchable self-coiling wet-adhesive patch for repairing esophageal fistulas according to claim 1, characterized in that, In S3, the drying temperature is 40~50℃ and the time is 10min.

6. The method for preparing a stretchable self-coiling wet-adhesive patch for repairing esophageal fistulas according to claim 1, characterized in that, In S3, sterilized bags are used for heat sealing during packaging.

7. The method for preparing a stretchable self-coiling wet-adhesive patch for repairing esophageal fistulas according to claim 1, characterized in that, In S3, the temperature for frozen storage is -20 to -40°C.

8. An adhesive patch prepared by the method for preparing a stretchable self-coiling wet adhesive patch for repairing esophageal fistulas according to any one of claims 1 to 7, characterized in that, It includes an elastic layer hydrogel and a constraint layer hydrogel; the elastic layer hydrogel is a highly cross-linked, low-modulus hydrogel; the constraint layer hydrogel is a low-cross-linked, high-modulus hydrogel.

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