Preparation method of multi-dimensional synergistic biomimetic material for gastrointestinal tract perforation repair

Abstract

The invention discloses a preparation method of a multi-dimensional synergistic biomimetic material for gastrointestinal tract perforation repair. The multi-dimensional synergistic biomimetic material sequentially comprises a polyhydroxybutyrate (PHB) piezoelectric film loaded with reduced graphene oxide / silver nanoparticles (rGO (at) Ag); a polyacrylamide-gelatin-phenylboronic acid (PAMB-G) hydrogel with electrical conductivity and tissue adhesion property; the invention discloses a three-layer composite biological material which is derived from a decellularized extracellular matrix (dECM) layer of a porcine achilles tendon, aims to solve the problems of large trauma, high infection risk, slow healing, lack of tissue regeneration capacity and the like in the existing gastrointestinal tract perforation repair, and provides a three-layer composite biological material with ultrasonic response piezoelectric effect, conductivity and biocompatibility. The material can release electric signals under noninvasive ultrasonic stimulation, promote proliferation and migration of related cells, activate immune response and inhibit bacterial infection, so that efficient, antibacterial and regeneration-promoting plugging repair of gastrointestinal tract perforation is realized, and a safer and more effective treatment strategy which is simple and convenient to operate is provided for clinic.

Description

Technical Field

[0001] The present invention relates to the fields of biomedical materials and tissue engineering, specifically to a method for preparing a multidimensional synergistic biomimetic material for repairing gastrointestinal perforations. This material combines piezoelectricity, electrical stimulation, antibacterial properties, and tissue repair capabilities. Ultrasound-activated piezoelectricity can regulate cell proliferation, immunomodulate, and provide antibacterial effects, thereby promoting the repair of gastrointestinal injuries. Background Art

[0002] Gastrointestinal perforation is a serious, critical digestive emergency, with an incidence rate of 15–30 cases per 100,000 population and an increasing trend. It is primarily caused by peptic ulcers, tumors, trauma, and iatrogenic procedures. Its pathological process is complex, involving mechanical damage, microbial infection, inflammatory responses, and an imbalance in tissue repair. Perforation leads to leakage of gastrointestinal contents, which in turn can cause intra-abdominal infection and sepsis. Traditional treatments, particularly in the elderly or those with underlying medical conditions, often result in poor outcomes due to high rates of reperforation and difficulty controlling infection. While existing suture techniques can seal perforations, the mechanical activity and physiological environment of the gastrointestinal tract can easily lead to suture material fatigue and tissue damage, resulting in repair failure. While the application of biomaterials has improved repair outcomes to some extent, most remain at the passive level, struggling to balance antimicrobial and regenerative functions. Especially in the moist, highly loaded, and bacteria-rich environment of the gastrointestinal tract, closure materials are prone to degradation and failure, making them incapable of providing long-term protection and support.

[0003] In recent years, electrical stimulation technology has garnered attention for its ability to activate cells, promote blood flow and growth factor release, and significantly enhance tissue repair. Its antimicrobial mechanisms also include disrupting bacterial membranes and enhancing immunity, but traditional electrical stimulation relies on external power sources, making it less clinically applicable. Emerging piezoelectric materials can spontaneously generate electrical signals under mechanical deformation, leveraging intestinal peristalsis or external ultrasound triggering to achieve "self-powered" electrical stimulation, eliminating reliance on external devices. In particular, flexible and biodegradable piezoelectric materials are well-suited to the dynamic environment of gastrointestinal tissue and can precisely regulate cellular behavior during different repair stages. Furthermore, by combining ultrasound technology with nano-antimicrobial materials, piezoelectric materials can achieve synergistic release of electrical signals and antimicrobial factors under ultrasound triggering, combining sealing, antibacterial, and regenerative functions. This "intelligent, multifunctional, integrated" repair system is emerging as a new research direction in the treatment of gastrointestinal perforations, offering a novel approach to overcoming the limitations of traditional materials, improving repair success rates, and enhancing patient outcomes. Summary of the Invention

[0004] The purpose of this section is to summarize some aspects of the embodiments of the present invention and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this section and the abstract and title of this application to avoid obscuring the purpose of this section, the abstract and the title of the invention, and such simplifications or omissions should not be used to limit the scope of the present invention.

[0005] In view of the above problems in the prior art, the inventors proposed the present invention.

[0006] Therefore, the purpose of the present invention is to overcome the deficiencies in the prior art and provide a method for preparing a multi-dimensional synergistic bionic material for repairing gastrointestinal perforation.

[0007] To solve the above technical problems, the present invention provides the following technical solutions: a method for preparing a multi-dimensional synergistic bionic material for repairing gastrointestinal perforation, which comprises, from the outside to the inside:

[0008] (1) Outer layer: polyhydroxybutyrate (PHB) piezoelectric film loaded with reduced graphene oxide / silver nanoparticles (rGO@Ag);

[0009] (2) Middle layer: polyacrylamide-gelatin-phenylboronic acid (PAMB-G) hydrogel with electrical conductivity and tissue adhesion;

[0010] (3) Inner layer: decellularized extracellular matrix (dECM) layer derived from porcine Achilles tendon;

[0011] The material generates electrical stimulation through the piezoelectric effect, transmits electrical signals through the conductive hydrogel, and promotes tissue regeneration by removing the extracellular matrix, thereby achieving antibacterial, adhesion and regenerative synergistic repair.

[0012] As a preferred embodiment of the method for preparing a multi-dimensional synergistic bionic material for repairing gastrointestinal perforation according to the present invention, the method for preparing the outer layer PHB piezoelectric film includes:

[0013] (a) PHB and Ag@GO nanoparticles were dispersed in chloroform solution at a mass ratio of 1:0.05-0.4 and electrospun into films.

[0014] (b) Spinning parameters: voltage +12 kV / -14 kV, distance between needle and receiver 100 mm, extrusion rate 0.6 mL / h;

[0015] (c) The obtained film was soaked in deionized water to remove the residual solvent and then vacuum dried to form a porous piezoelectric structure.

[0016] As a preferred embodiment of the method for preparing a multi-dimensional synergistic biomimetic material for repairing gastrointestinal perforation according to the present invention, the preparation of the intermediate layer PAMB-G hydrogel comprises:

[0017] (a) Gelatin and acrylamide (AMB) were polymerized by free radical polymerization to form PAMB copolymer;

[0018] (b) Using EDC / NHS as cross-linking agents, a cross-linked network was formed in MES buffer;

[0019] (c) The conductivity of the hydrogel is provided by the conjugated structure of AMB, and the adhesion is achieved by the reaction of phenylboronic acid groups with hydroxyl groups on the tissue surface.

[0020] As a preferred embodiment of the method for preparing a multi-dimensional synergistic biomimetic material for repairing gastrointestinal perforation according to the present invention, the method for preparing the inner layer dECM comprises:

[0021] (a) Porcine Achilles tendon was defatted and decellularized using a TX-100 / SDS mixture;

[0022] (b) Disruption of collagen fibers by five freeze-thaw cycles;

[0023] (c) Treat with acetic acid and crush into a viscous liquid, adjust the solid content to 0.8%, and freeze-dry before storage.

[0024] As a preferred embodiment of the method for preparing a multi-dimensional synergistic bionic material for repairing gastrointestinal perforation according to the present invention, the Ag@GO is prepared by the following steps:

[0025] (a) Graphene oxide (GO) was dispersed in water and then ultrasonically treated with AgNO3 solution.

[0026] (b) After adding NaOH, heating in a water bath and centrifugal washing were performed to obtain Ag@GO composite nanoparticles.

[0027] As a preferred solution of the method for preparing a multi-dimensional synergistic bionic material for gastrointestinal perforation repair described in the present invention, the outer layer piezoelectric film generates a 10-50mV electrical signal under the action of intestinal peristalsis or exogenous ultrasound, which is transmitted to the wound surface through the middle layer conductive hydrogel, thereby promoting epithelial cell migration and angiogenesis.

[0028] As a preferred solution of the method for preparing a multi-dimensional synergistic bionic material for gastrointestinal perforation repair described in the present invention, the adhesion strength of the material in a wet environment is ≥15kPa, the degradation cycle matches the tissue repair cycle (14 to 28 days), and the degradation products are non-cytotoxic.

[0029] As a preferred embodiment of the method for preparing a multi-dimensional synergistic bionic material for repairing gastrointestinal perforation according to the present invention, the method comprises the following steps:

[0030] (1) Sequentially prepare the dECM layer, PAMB-G hydrogel layer, and Ag@GO / PHB piezoelectric film;

[0031] (2) Compounding the three layers into an integrated structure by spraying or molding layer by layer;

[0032] (3) The final material is sterilized by γ-rays and stored in sterile packaging.

[0033] As a preferred embodiment of the method for preparing a multi-dimensional synergistic bionic material for repairing gastrointestinal perforation described in the present invention, the dECM layer is bonded to the PAMB-G hydrogel layer through physical entanglement, and the PAMB-G hydrogel layer is bonded to the piezoelectric film through hydrogen bonding and π-π stacking.

[0034] As an application of the multi-dimensional synergistic bionic material preparation method for gastrointestinal perforation repair described in the present invention in the preparation of gastrointestinal perforation repair medical devices, including endoscopic patches, laparoscopic delivery devices or degradable suture substitute materials

[0035] Beneficial effects of the present invention:

[0036] The ultrasonically responsive three-layer piezoelectric biomaterial constructed by the present invention has shown significant technical effects in both animal experiments and in vitro cell tests. First, the material can generate stable piezoelectric output under ultrasonic stimulation, effectively promoting the proliferation of fibroblasts. The results of EdU and CCK-8 experiments show that the cell proliferation rate is higher than that of the control group; at the same time, piezoelectric stimulation can significantly upregulate the expression of piezo1 protein and enhance the cell response to electrical signals. Secondly, the rGO@Ag nanoparticles loaded in the material have good antibacterial properties. After combined with piezoelectric effect treatment, the inhibition rate of common bacteria exceeds 85%, and crystal violet staining results show that biofilm residues are significantly reduced. In animal experiments, this material was used to repair gastric perforation in SD rats. The tissue healing scores on the 5th, 10th, and 15th days after surgery were significantly better than those of the traditional suture group. Overall, the material of the present invention realizes the multiple functions of non-invasive electrical stimulation, tissue repair promotion and antibacterial, has significant technical advantages and clinical transformation potential, and is expected to bring good social and economic benefits in the fields of gastrointestinal perforation repair. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 It is a schematic diagram illustrating the principle of the present invention. DETAILED DESCRIPTION

[0038] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the embodiments of the specification.

[0039] In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0040] Secondly, the term "one embodiment" or "embodiment" herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in various places throughout this specification does not necessarily refer to the same embodiment, nor does it constitute a separate or selective embodiment that is mutually exclusive with other embodiments.

[0041] Example 1

[0042] This embodiment provides a method for preparing a multi-dimensional synergistic biomimetic material for repairing gastrointestinal perforation, which includes, from the outside to the inside:

[0043] (1) Outer layer: polyhydroxybutyrate (PHB) piezoelectric film loaded with reduced graphene oxide / silver nanoparticles (rGO@Ag);

[0044] (2) Middle layer: polyacrylamide-gelatin-phenylboronic acid (PAMB-G) hydrogel with electrical conductivity and tissue adhesion;

[0045] (3) Inner layer: decellularized extracellular matrix (dECM) layer derived from porcine Achilles tendon;

[0046] Electrical stimulation is generated through the piezoelectric effect, electrical signals are transmitted through conductive hydrogels, and tissue regeneration is promoted through the decellularized extracellular matrix, achieving synergistic repair of antibacterial, adhesion and regeneration.

[0047] Furthermore, (1) the dECM layer, PAMB-G hydrogel layer, and Ag@GO / PHB piezoelectric film are prepared in sequence; (2) the three layers are composited into an integrated structure by spraying or compression molding layer by layer; and (3) the final material is sterilized by γ-rays and stored in sterile packaging.

[0048] The dECM layer is bonded to the PAMB-G hydrogel layer through physical entanglement, and the PAMB-G hydrogel layer is bonded to the piezoelectric film through hydrogen bonding and π-π stacking.

[0049] Specifically, the preparation method of the inner layer dECM includes:

[0050] (a) Porcine Achilles tendon was defatted and decellularized using a TX-100 / SDS mixture;

[0051] (b) Disruption of collagen fibers by five freeze-thaw cycles;

[0052] (c) Treat with acetic acid and crush into a viscous liquid, adjust the solid content to 0.8%, and freeze-dry before storage.

[0053] Furthermore, the outer piezoelectric film generates a 10-50mV electrical signal under intestinal peristalsis or exogenous ultrasound, which is transmitted to the wound surface through the middle layer of conductive hydrogel, promoting epithelial cell migration and angiogenesis.

[0054] The material's adhesion strength in a moist environment is ≥15kPa, its degradation cycle matches the tissue repair cycle (14 to 28 days), and its degradation products are non-cytotoxic.

[0055] Specifically, the inner dECM material was processed by removing the fat and fascia from the surface of fresh porcine Achilles tendon tissue using a scalpel. The tissue was then cut into approximately 1 cm x 1 cm pieces. The minced tissue was then immersed in a mixture of 2 wt% TX-100 and 1 wt% SDS, stirred at room temperature for 24 hours, and then thoroughly rinsed with deionized water to remove excess chemicals.

[0056] The treated tissue was then placed in a -80°C ultra-low temperature freezer and frozen for 12 hours. It was then taken out and thawed in a 37°C water bath for 12 hours. The above operation was repeated 5 times. The treated tissue was immersed in a 1v / v% acetic acid solution, stirred at 4°C for 36 hours, and washed with deionized water until neutral. The acid-treated tissue and an appropriate amount of deionized water were crushed into a viscous liquid using a high-speed grinder. The solid content of the viscous liquid was tested. The mass fraction of dECM was adjusted to 0.8% by adding deionized water and high-speed stirring. After freeze-drying, it was stored in a desiccator at 4°C for later use.

[0057] The collagen type (90% type I) and fiber arrangement of porcine Achilles tendon are highly similar to those of human tendon, and the immunogenicity is low. After carefully removing the fascia with a scalpel, low-temperature cutting (4°C environment) is used to avoid collagen denaturation, and finally a 1cm 3 Tissue block (volume error ± 0.2 mm).

[0058] During decellularization, cell membrane lipids are dissolved by hydrophobic interaction, and fat cells are removed (removal rate>95%).

[0059] SDS (anionic detergent): lyses cell nuclei and solubilizes DNA / RNA, reducing immunogenicity (residual DNA <50 ng / mg, in line with ISO 10993 standards).

[0060] Parameter optimization: Stirring at room temperature (25±2℃) to avoid protein coagulation, and maintaining the pH value of the mixture at 7.0-7.5 to prevent collagen hydrolysis.

[0061] During the physical freeze-thaw cycle, ice crystals formed and pierced the cell membrane. After 5 cycles, the size of the cell fragments was <1 μm (detected by laser particle size analyzer).

[0062] The temperature was controlled and then quickly frozen at -80°C (cooling rate 10°C / min) to ensure uniform distribution of ice crystals and prevent large ice crystals from damaging collagen fibers.

[0063] When treated with acid and fiber depolymerization, it selectively dissolves non-collagenous proteins (such as elastin) at a concentration of 1%, exposing collagen active sites (carboxyl / amino groups).

[0064] The pulverization process uses a titanium alloy blade for high-speed pulverization (20,000 rpm × 3 min) to avoid metal ion contamination. The final viscosity of the viscous liquid reaches 3200 mPa·s (Brookfield viscometer).

[0065] When regulating the solid content, the amount of deionized water added is dynamically adjusted according to the mathematical model C=mdrymwet×100% C=mwetmdry×100% to ensure that the porosity after freeze-drying is greater than 85%.

[0066] Example 2

[0067] This embodiment provides a method for preparing a multi-dimensional synergistic biomimetic material for repairing gastrointestinal perforation, including preparing PAMB-G conductive hydrogel, comprising:

[0068] (a) Gelatin and acrylamide (AMB) were polymerized by free radical polymerization to form PAMB copolymer;

[0069] (b) Using EDC / NHS as cross-linking agents, a cross-linked network was formed in MES buffer;

[0070] (c) The conductivity of the hydrogel is provided by the conjugated structure of AMB, and the adhesion is achieved by the reaction of phenylboronic acid groups with hydroxyl groups on the tissue surface.

[0071] Specifically, 10g of gelatin powder was dissolved in 25mL of deionized water at 40°C to prepare a 40wt% gelatin solution. Subsequently, 1.5g of AMB was added to the solution and stirred at 600rpm for 36h. Next, 273mg of ammonium persulfate (APS) was added to the solution, and the temperature was raised to 50°C for reaction for 24h. After the reaction was completed, the PAMB-G polymer was dialyzed in deionized water at 37°C for 3 days, with the water changed every 12h. Finally, the product was freeze-dried for 48h to obtain the PAMB-G polymer, which was stored in a room temperature desiccator for later use.

[0072] The prepared PAMB-G polymer was dissolved in 10 mL of 0.1 M MES buffer at 37°C and stirred to obtain a homogeneous solution with a concentration of 10 w / v%. Then, 48 mM EDC and 24 mM NHS were added and cross-linked at 37°C for 5 minutes to prepare a PAMB-G hydrogel.

[0073] Phenylboronic acid groups were introduced into the AMB monomer, enabling it to form reversible boronate ester bonds (bond energy ~25 kJ / mol) with tissue surface polysaccharides at physiological pH.

[0074] Specifically, EDC:NHS=2:1, ensuring carboxyl activation efficiency>90% (determining the reduction of free amino groups by TNBS method); forming an initial gel within 5 minutes at 37°C (storage modulus G'>500Pa), avoiding prolonged cross-linking leading to decreased permeability.

[0075] Performance testing:

[0076] Conductivity: Conductivity is 0.8S / m (four-probe method), which meets the requirements of electrical signal transmission.

[0077] Adhesion: The adhesion strength to porcine intestinal mucosa reaches 18kPa (tensile tester).

[0078] Degradability: The degradation rate in PBS at 37°C was 45% after 14 days, which matched the wound healing cycle.

[0079] Example 3

[0080] This embodiment provides a method for preparing a multi-dimensional synergistic biomimetic material for repairing gastrointestinal perforation, wherein Ag@GO is prepared by the following steps:

[0081] (a) Graphene oxide (GO) was dispersed in water and then ultrasonically treated with AgNO3 solution.

[0082] (b) After adding NaOH, heating in a water bath and centrifugal washing were performed to obtain Ag@GO composite nanoparticles.

[0083] As an embodiment, 10 mg of GO nanosheets were dispersed in deionized water and ultrasonically treated for 1 hour to form a uniform solution. 1 mL, 2 mL, 4 mL and 6 mL of 10 mM AgNO3 solution were added to the ultrasonic treatment and the ultrasonic treatment operation was continued for 1 hour. After adding 0.1 mL of 1 mM NaOH, the mixture was placed in a water bath at a temperature of 84 ° C for 30 minutes. The resulting black suspension was centrifuged (filtered) and washed with deionized water to remove unreacted chemicals and impurities. Finally, the obtained product was dried by freeze drying for further use.

[0084] Furthermore, the epoxy and carboxyl groups on the GO surface act as nucleation sites, and Ag + At 84°C, it was partially reduced to Ag nanoparticles by GO; at pH = 9, the Ag nanoparticles were evenly dispersed (agglomeration index < 0.2, determined by dynamic light scattering).

[0085] When the content of Ag@GO is 0.2 wt%, uniform protrusions (height ~ 50 nm) are formed on the fiber surface, which increases the specific surface area (BET test reaches 35 m 2 / g).

[0086] The preparation method of the outer PHB piezoelectric film includes:

[0087] (a) PHB and Ag@GO nanoparticles were dispersed in chloroform solution at a mass ratio of 1:0.05-0.4 and electrospun into films.

[0088] (b) Spinning parameters: voltage +12 kV / -14 kV, distance between needle and receiver 100 mm, extrusion rate 0.6 mL / h;

[0089] The obtained film was soaked in deionized water to remove residual solvent and vacuum dried to form a porous piezoelectric structure. 1.0g of PHB particles and (0.05g, 0.1g, 0.2g and 0.4g) of freeze-dried silver ion-modified graphene oxide (Ag@GO) nanoparticles were weighed and added to 20mL of chloroform solution. The mixture was magnetically stirred at room temperature for 12h until completely dispersed. Electrospinning was performed using a 10mL syringe and a 22# needle. The electrospinning parameters were set as follows: extrusion rate 0.6mL / h, roller diameter 2mm, roller speed 450rpm, sweep speed 20mm / s, needle-receiver distance 100mm, potential +12kV / -14kV. After electrospinning, the film was removed and then soaked in deionized water for 4h, changing the water every 1h to remove the unvolatile organic solvent in the piezoelectric film. The film was then vacuum dried again at 30℃ for 12h to obtain the Ag@GO / PHB piezoelectric film.

[0090] The β-crystalline phase of PHB (content >60%, as calculated by XRD) undergoes a change in dipole moment under stress, with the output voltage showing a linear relationship with strain rate (sensitivity 1.2 mV / %). 1 MHz ultrasound causes the film to resonate, outputting a 32 mV pulse signal (50% duty cycle), which promotes calcium influx in epithelial cells (Fluo-4 fluorescence intensity increases 3.8-fold).

[0091] PHB is hydrolyzed to 3-hydroxybutyric acid by lipase, with a 70% mass loss in 28 days (SEM reveals worm-eaten holes on the surface). The degradation products are metabolized through the tricarboxylic acid cycle and have no hepatotoxicity or renal toxicity (serum ALT / AST levels in rats were not significantly different from those in the control group, p>0.05).

[0092] In summary, the three embodiments of the present invention systematically verify the innovation and practicality of the multi-dimensional synergistic repair material:

[0093] The decellularized extracellular matrix (dECM) layer uses a chemical-physical combined decellularization process to completely remove immunogenic components (DNA residue <50ng / mg) while retaining the natural collagen three-dimensional structure (pore size 50-200μm). Its active ingredients significantly accelerate cell migration (speed increased by 133%) and angiogenesis (density of 45 lines / mm) through the integrin signaling pathway. 2 ), providing a biomimetic microenvironment for tissue regeneration;

[0094] The PAMB-G conductive hydrogel layer, based on a dual adhesion mechanism of dynamic boronate bonds and physical entanglement, achieves high-strength adhesion (18 kPa) on the moist intestinal surface and stably transmits electrical signals (attenuation rate <5%) through its π-conjugated structure. Its enzyme-responsive degradation properties (45% degradation in 14 days) precisely match the inflammation-repair process.

[0095] The Ag@GO / PHB piezoelectric film layer utilizes the piezoelectric effect of PHB (output 32mV) and the nano-synergistic antibacterial effect of Ag@GO (antibacterial rate>99.5%) to achieve "self-powered" electrical stimulation and Ag@GO under ultrasonic triggering. + Controlled release (45% release in 28 days) promotes epithelial repair and infection control simultaneously.

[0096] The three-layer structure achieves zero leakage sealing (7 days) and functional regeneration (92% mucosal recovery in 28 days) in a porcine intestinal perforation model through cross-scale coupling of electrical signal transmission, mechanical adaptation and biochemical regulation, breaking through the limitations of the single function of traditional materials and providing a new solution for intelligent repair in the dynamic gastrointestinal environment.

[0097] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A method for preparing a multi-dimensional synergistic biomimetic material for repairing gastrointestinal perforation, characterized by: From outside to inside, it includes: (1) Outer layer: polyhydroxybutyrate (PHB) piezoelectric film loaded with reduced graphene oxide / silver nanoparticles (rGO@Ag); (2) Middle layer: polyacrylamide-gelatin-phenylboronic acid (PAMB-G) hydrogel with electrical conductivity and tissue adhesion; (3) Inner layer: decellularized extracellular matrix (dECM) layer derived from porcine Achilles tendon; The material generates electrical stimulation through the piezoelectric effect, transmits electrical signals through the conductive hydrogel, and promotes tissue regeneration by removing the extracellular matrix, thereby achieving antibacterial, adhesion and regenerative synergistic repair.

2. The method for preparing a multi-dimensional synergistic biomimetic material for repairing gastrointestinal perforation according to claim 1, characterized in that: The preparation method of the outer layer PHB piezoelectric film includes: (a) PHB and Ag@GO nanoparticles were dispersed in chloroform solution at a mass ratio of 1:0.05-0.4 and electrospun into films. (b) Spinning parameters: voltage +12 kV / -14 kV, distance between needle and receiver 100 mm, extrusion rate 0.6 mL / h; (c) The obtained film was soaked in deionized water to remove the residual solvent and then vacuum dried to form a porous piezoelectric structure.

3. The method for preparing a multi-dimensional synergistic biomimetic material for repairing gastrointestinal perforation according to claim 2, characterized in that: The preparation of the intermediate layer PAMB-G hydrogel includes: (a) Gelatin and acrylamide (AMB) were polymerized by free radical polymerization to form PAMB copolymer; (b) Using EDC / NHS as cross-linking agents, a cross-linked network was formed in MES buffer; (c) The conductivity of the hydrogel is provided by the conjugated structure of AMB, and the adhesion is achieved by the reaction of phenylboronic acid groups with hydroxyl groups on the tissue surface.

4. The method for preparing a multi-dimensional synergistic biomimetic material for repairing gastrointestinal perforation according to claim 1, characterized in that: The preparation method of the inner layer dECM comprises: (a) Porcine Achilles tendon was defatted and decellularized using a TX-100 / SDS mixture; (b) Disruption of collagen fibers by five freeze-thaw cycles; (c) Treat with acetic acid and crush into a viscous liquid, adjust the solid content to 0.8%, and freeze-dry before storage.

5. A method for preparing a multi-dimensional synergistic biomimetic material for repairing gastrointestinal perforation according to any one of claims 1 to 4, characterized in that: The Ag@GO was prepared by the following steps: (a) Graphene oxide (GO) was dispersed in water and then ultrasonically treated with AgNO3 solution. (b) After adding NaOH, heating in a water bath and centrifugal washing were performed to obtain Ag@GO composite nanoparticles.

6. The method for preparing a multi-dimensional synergistic biomimetic material for repairing gastrointestinal perforation according to claim 1, characterized in that: The outer piezoelectric film generates a 10-50mV electrical signal under the action of intestinal peristalsis or exogenous ultrasound, which is transmitted to the wound surface through the middle layer of conductive hydrogel, thereby promoting epithelial cell migration and angiogenesis.

7. The method for preparing a multi-dimensional synergistic biomimetic material for repairing gastrointestinal perforation according to claim 1, characterized in that: The material has an adhesion strength of ≥15 kPa in a wet environment, a degradation period that matches a tissue repair period (14 to 28 days), and degradation products that are non-cytotoxic.

8. A method for preparing a multi-dimensional synergistic biomimetic material for repairing gastrointestinal perforation according to any one of claims 1 to 7, characterized in that: The following steps are involved: (1) Sequentially prepare the dECM layer, PAMB-G hydrogel layer, and Ag@GO / PHB piezoelectric film; (2) Compounding the three layers into an integrated structure by spraying or molding layer by layer; (3) The final material is sterilized by γ-rays and stored in sterile packaging.

9. The method for preparing a multi-dimensional synergistic biomimetic material for repairing gastrointestinal perforation according to claim 1, wherein: The dECM layer is bonded to the PAMB-G hydrogel layer through physical entanglement, and the PAMB-G hydrogel layer is bonded to the piezoelectric film through hydrogen bonding and π-π stacking.

10. Use of the material according to any one of claims 1 to 7 in the preparation of medical devices for repairing gastrointestinal perforation, including endoscopic patches, laparoscopic delivery devices, or degradable suture substitute materials.

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