Dressing patch and preparation method thereof

Abstract

The invention provides a dressing patch and a preparation method thereof, relates to the technical field of medical supplies, and aims at solving the problems that a traditional dressing is poor in water absorption, insufficient in breathability and poor in antibacterial property. The dressing patch is composed of an application layer, an absorption layer and a protection layer and is prepared through a multi-step process. The preparation method comprises the following steps: firstly, performing enzymolysis treatment on spirulina powder and undaria pinnatifida powder to prepare antibacterial polypeptide powder; secondly, loading the antibacterial polypeptide into the Zn / A < 1 >-LDH powder through ion exchange loading; combining the LDH composite powder loaded with the antibacterial polypeptide with nano-silver composite fiber cloth to form a pasting layer; and finally, fixing the spunlace non-woven fabric serving as an absorption layer on the application layer, and covering the PCL / starch porous film to prepare the degradable dressing patch. Experimental results show that the dressing patch has a relatively strong inhibition effect on common pathogenic bacteria, is high in water absorption rate and high in liquid retention capacity, can quickly release antibacterial polypeptide in a local heating environment after human body infection is simulated, and has good antibacterial performance and temperature responsiveness.

Description

Technical Field

[0001] The present invention relates to the technical field of medical supplies, and specifically relates to a dressing patch and a preparation method thereof. Background Art

[0002] With the development of modern medicine, the requirements for wound care and dressings are getting higher and higher. Traditional dressings often have problems such as poor water absorption, insufficient air permeability, and lack of antibacterial properties, and cannot effectively meet the clinical needs. In recent years, the application of biomaterials has gradually received attention. Especially natural polymer materials such as chitosan and polylactic acid have become the research hotspots of new dressings due to their good biocompatibility and biodegradability. These materials can not only promote wound healing but also reduce the impact on the environment, which conforms to the concept of sustainable development. Therefore, developing new dressing patches with high water absorption, good waterproof and air permeability, and antibacterial properties has become an important research direction at present. Summary of the Invention

[0003] In view of the above problems, the present invention provides a dressing patch and a preparation method thereof.

[0004] To achieve the above objectives, the present invention is realized through the following technical solutions: A preparation method of a dressing patch, comprising the following steps:

[0005] S1: Mix spirulina powder, wakame powder and pure water, and perform mechanical cell disruption by high-speed stirring. The rotation speed is controlled at 8000 - 10000 rpm, and stir for 10 - 15 minutes until the algal powder is fully dispersed to form a uniform disrupted liquid. Adjust the pH of the disrupted liquid to 7.5 - 8.0 with a buffer pH agent, add trypsin and enzymolyze for 3 - 5 hours, control the temperature at 36.5°C - 4°C, to obtain a trypsin enzymolyzed liquid. Adjust the pH of the trypsin enzymolyzed liquid to 6.5 - 7 with a buffer pH agent, add papain and enzymolyze for 2 - 3 hours, control the temperature at 5°C - 60°C, to obtain a double-hydrolysis enzymolyzed liquid. Perform enzyme inactivation treatment on the double-hydrolysis enzymolyzed liquid, centrifuge the enzyme-inactivated double-hydrolysis enzymolyzed liquid at high speed, take the centrifuged supernatant for ultrafiltration to obtain an ultrafiltered enzymolyzed liquid, and freeze-dry the ultrafiltered enzymolyzed liquid to obtain an antibacterial polypeptide powder;

[0006] S2: Dissolve Zn(NO3)2·6H2O and Al(NO3)3·9H2O in deionized water a, stir evenly. Under stirring conditions, add 2M NaOH solution dropwise to the solution, adjust the pH to 9 - 10, keep the reaction temperature at 95°C and reflux for 24 hours. After the reaction is completed, centrifuge to separate the precipitate, and wash it with deionized water multiple times until the pH value of the washing solution is close to neutral. Dry the washed precipitate at 60°C to obtain Zn / Al-LDH powder. Add the Zn / Al-LDH powder to deionized water b to form an LDH suspension. Add the antibacterial polypeptide powder to the LDH suspension and stir at room temperature for 2h for ion exchange loading. During the exchange loading process, control the pH value of the suspension at 7.2 - 7.5. After the loading is completed, filter and dry to obtain the Zn / Al-LDH powder loaded with antibacterial polypeptide. Add N-isopropylacrylamide, N,N'-methylenebisacrylamide, and photoinitiator 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylpropiophenone to deionized water c in sequence, with a stirring speed of 500 - 800 rpm, and stir for 3 - 40 min to obtain a prepolymer solution. Add the Zn / Al-LDH powder loaded with antibacterial polypeptide to the prepolymer solution, and ultrasonically disperse for 15 - 20 min to form a uniform LDH prepolymer suspension. After deoxygenating with nitrogen for 10 min, place the LDH prepolymer suspension in a quartz glass dish and irradiate it with ultraviolet light to initiate polymerization. The wavelength of the ultraviolet light source is 365 nm, and the light intensity is 10 - 15 mW / cm 2 , the irradiation time is 10 - 15 min, the temperature is controlled at 25°C, and during this period, magnetic stirring is carried out at 200 - 300 rpm to keep the particles dispersed. After the polymerization is completed, centrifuge, wash, and dry to obtain the LDH composite powder loaded with antibacterial polypeptide;

[0007] S3: Immerse the polylactic acid fiber in the silver nitrate solution, add a reducing agent, adjust the pH value to 8 - 10, control the temperature at 40°C - 55°C, and react for 45 - 60 min to obtain the modified polylactic acid fiber. Then heat-treat the modified polylactic acid fiber, control the temperature at 80 - 120°C, and the time is 10 - 15 min. Card the heat-treated modified polylactic acid fiber, and after carding, compound silk fibroin fiber through electrospinning technology. The mass ratio of the modified polylactic acid fiber to the silk fibroin fiber is 8:2 to form a uniform nano-silver composite fiber cloth;

[0008] S4: Mix chitosan, cross-linking agent, moisturizer, thickener, and dilute acid solution evenly, add the LDH composite powder loaded with antibacterial polypeptide prepared in S2, control the temperature at 40°C - 60°C, and stir for 50 - 60 min to obtain a uniform chitosan cross-linked matrix. Immerse the nano-silver composite fiber cloth prepared in S3 into the chitosan cross-linked matrix with the temperature maintained above 40°C, so that the chitosan cross-linked matrix uniformly penetrates into the pores of the nano-silver composite fiber cloth, and form a composite structure after cooling to obtain the dressing layer;

[0009] S5: Lay the spunlace nonwoven fabric as the absorbent layer flat on the dressing layer and fix it with hot melt adhesive. Make a porous film from polycaprolactone by electrospinning, cover the absorbent layer and hot press the edges to finally obtain a degradable dressing patch.

[0010] Preferably, the spirulina powder, wakame powder, purified water, trypsin, and papain are in the weight parts of 10 - 15 parts of spirulina powder, 10 - 15 parts of wakame powder, 50 - 80 parts of purified water, 0.3 - 0.5 parts of trypsin, and 0.2 - 0.5 parts of papain.

[0011] Preferably, the mass parts of Zn(NO3)2·6H2O, Al(NO3)3·9H2O, deionized water a, deionized water b, antibacterial polypeptide powder, N-isopropylacrylamide, N,N'-methylenebisacrylamide, photoinitiator 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylpropiophenone, and deionized water c are 23 - 35 parts of Zn(NO3)2·6H2O, 10 - 15 parts of Al(NO3)3·9H2O, 200 - 300 parts of deionized water a, 180 - 250 parts of deionized water b, 3 - 5 parts of antibacterial polypeptide powder, 20 - 30 parts of N-isopropylacrylamide, 1 - 2 parts of N,N'-methylenebisacrylamide, 0.1 - 0.3 parts of photoinitiator 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylpropiophenone, and 200 - 250 parts of deionized water c.

[0012] Preferably, the chitosan, crosslinking agent, humectant, thickening agent, antibacterial polypeptide powder, and dilute acid solution are in the weight parts of 30 - 50 parts of chitosan, 15 - 30 parts of crosslinking agent, 9 - 15 parts of humectant, 6 - 12 parts of thickening agent, 24 - 37 parts of LDH composite powder loaded with antibacterial polypeptide, and 180 - 240 parts of dilute acid solution.

[0013] The Zn / Al-LDH powder is a material with a layered structure. The interlayer of LDH contains exchangeable anions, mainly nitrate ions and hydroxide ions. The antibacterial polypeptide molecules carry negative charges and can undergo ion exchange with the anions in the LDH interlayer, thus embedding into the interlayer structure of LDH. Functional groups such as carboxyl (-COOH) and amino (-NH2) in the antibacterial polypeptide molecules can have electrostatic interactions with the metal cations (such as Zn2+ and Al3+) on the surface of LDH, enabling the combination of Zn / Al-LDH powder and antibacterial polypeptide molecules. The layered structure of Zn / Al-LDH is sensitive to pH value changes and can gradually release antibacterial polypeptides under slightly acidic conditions to achieve a continuous antibacterial effect.

[0014] The N-isopropylacrylamide (NIPAM) is a monomer with thermosensitivity. Its polymer, poly(N-isopropylacrylamide) (PNIPAM), exhibits an obvious lower critical solution temperature (LCST) in water. When the temperature is lower than the LCST, it has strong hydrophilicity, and when the temperature is higher than the LCST, its hydrophobicity increases. This property makes it have broad application prospects in the biomedical field. As a cross-linking agent, MBAA can undergo a cross-linking reaction with NIPAM to form a PNIPAM polymer network, significantly improving the mechanical strength and stability of the polymer, while regulating the pore structure and thermosensitivity. The photoinitiator generates free radicals under ultraviolet light irradiation, initiating the polymerization reaction of NIPAM and MBAA, making the polymerization process efficient, rapid, and controllable under mild conditions.

[0015] Preferably, the buffer pH agent is composed of sodium dihydrogen phosphate and disodium hydrogen phosphate.

[0016] Preferably, the conditions for ultrafiltration are that the ultrafiltration pressure is controlled at 0.1 - 0.5 MPa, and an ultrafiltration membrane with a molecular weight cut-off of 3000 - 5000 Daltons is selected.

[0017] Preferably, the silver nitrate solution is a 0.1 - 0.2 mol / L silver nitrate solution.

[0018] Preferably, the reducing agent is a 0.3 - 0.5 mol / L sodium citrate solution.

[0019] Preferably, the cross-linking agent is citric acid.

[0020] Preferably, the humectant is sodium hyaluronate.

[0021] Preferably, the thickening agent is composed of carboxymethyl cellulose and tea polyphenols, and the mass ratio of carboxymethyl cellulose to tea polyphenols is 3:1.

[0022] Preferably, the dilute acid solution is a 1% - 2% acetic acid solution.

[0023] Beneficial effects

[0024] The present invention provides a dressing patch and a preparation method thereof. It has the following beneficial effects:

[0025] 1. The dressing patch prepared by the present invention is obtained through specific preparation steps, including using spunlace non-woven fabric as the absorption layer and polyethylene film as the protective layer, and using hot melt adhesive for fixation and bonding, thereby obtaining a dressing patch with high water absorption and good waterproof and breathable properties. This property enables the dressing patch to quickly absorb wound exudate, while preventing water penetration, keeping the wound dry, and being beneficial to wound healing.

[0026] 2. The dressing patch prepared by the present invention is added with LDH composite powder loaded with antibacterial polypeptides prepared by a specific process. The antibacterial polypeptides, nano silver and chitosan cross-linked matrix cooperate with each other in the dressing layer to exert a synergistic bactericidal effect, and show strong inhibitory effects on common pathogenic bacteria such as Staphylococcus aureus, Escherichia coli and Salmonella typhi in experiments. This helps to reduce the risk of wound infection and promote wound healing. Detailed implementation manners

[0027] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0028] Example 1:

[0029] A preparation method of a dressing patch includes the following steps:

[0030] S1: Mix 12 parts of spirulina powder, 13 parts of wakame powder and 65 parts of purified water, and perform mechanical cell disruption by high-speed stirring at a rotation speed of 8000 rpm for 10 min until the algal powder is fully dispersed to form a uniform disrupted solution. Adjust the pH of the disrupted solution to 7.8 with a buffer pH agent, add 0.4 part of trypsin and enzymolyze for 3 h at a temperature controlled at 36.5°C to obtain a trypsin enzymolyzed solution. Adjust the pH of the trypsin enzymolyzed solution to 6.8 with a buffer pH agent, add 0.3 part of papain, and enzymolyze for 3 h at a temperature controlled at 55°C to obtain a double-hydrolysis enzymolyzed solution. Perform enzyme inactivation treatment on the double-hydrolysis enzymolyzed solution, subject the enzyme-inactivated double-hydrolysis enzymolyzed solution to high-speed centrifugation, and take the centrifuged supernatant for ultrafiltration to obtain an ultrafiltered enzymolyzed solution. Freeze-dry the ultrafiltered enzymolyzed solution to obtain antibacterial polypeptide powder.

[0031] S2: Dissolve 32 parts of Zn(NO3)2·6H2O and 13 parts of Al(NO3)3·9H2O in 260 parts of deionized water a, stir evenly. Under stirring conditions, add 2M NaOH solution dropwise to the solution, adjust the pH to 9.6, keep the reaction temperature at 95°C and reflux for 24 hours. After the reaction is completed, centrifuge to separate the precipitate, and wash it with deionized water multiple times until the pH value of the washing solution is close to neutral. Dry the washed precipitate at 60°C to obtain Zn / Al-LDH powder. Add the Zn / Al-LDH powder to 220 parts of deionized water b to form an LDH suspension. Add 4 parts of the antibacterial polypeptide powder to the LDH suspension, stir at room temperature for 2 h for ion exchange loading. During the exchange loading process, control the pH value of the suspension at 7.3. After the loading is completed, filter and dry to obtain the Zn / Al-LDH powder loaded with antibacterial polypeptide. Add 25 parts of N-isopropylacrylamide, 2 parts of N,N'-methylenebisacrylamide, and 0.2 part of the photoinitiator 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylpropiophenone to 200 parts of deionized water c in sequence, stir at a speed of 800 rpm for 35 min to obtain a prepolymer solution. Add the Zn / Al-LDH powder loaded with antibacterial polypeptide to the prepolymer solution, ultrasonically disperse for 18 min to form a uniform LDH prepolymer suspension. After deoxygenating with nitrogen for 10 min, place the LDH prepolymer suspension in a quartz glass dish and irradiate it with ultraviolet light to initiate polymerization. The wavelength of the ultraviolet light source is 365 nm, and the light intensity is 12 mW / cm 2 , the irradiation time is 14 min, the temperature is controlled at 25°C, and magnetic stirring is carried out at 280 rpm during this period to keep the particles dispersed. After the polymerization is completed, centrifuge, wash, and dry to obtain the LDH composite powder loaded with antibacterial polypeptide.

[0032] S3: Immerse the polylactic acid fiber in a 0.15 mol / L silver nitrate solution, add a 0.4 mol / L sodium citrate solution as a reducing agent, adjust the pH value to 9, control the temperature at 48°C, and react for 50 min to obtain the modified polylactic acid fiber. Then heat-treat the modified polylactic acid fiber, control the temperature at 100°C, and the time is 12 min. Card the heat-treated modified polylactic acid fiber, and compound silk fibroin fiber through electrospinning technology after carding. The mass ratio of the modified polylactic acid fiber to the silk fibroin fiber is 8:2 to form a uniform nano-silver composite fiber cloth.

[0033] S4: Mix 45 parts of chitosan, 21 parts of citric acid, 12 parts of sodium hyaluronate, 3 parts of carboxymethyl cellulose, 1 part of tea polyphenol and 210 parts of 1.5% dilute acid solution evenly, add 29 parts of the LDH composite powder loaded with antibacterial polypeptide prepared in S2, control the temperature at 50 °C, stir for 55 min to obtain a uniform chitosan cross-linked matrix. Immerse the nano-silver composite fiber cloth prepared in S3 into the chitosan cross-linked matrix with the temperature maintained above 40 °C, so that the chitosan cross-linked matrix uniformly penetrates into the pores of the nano-silver composite fiber cloth to form a composite structure and obtain a dressing layer.

[0034] S5: Lay the spunlace non-woven fabric as the absorption layer on the dressing layer and fix it with hot melt adhesive. Make a porous film from polycaprolactone by electrospinning, cover the absorption layer and heat-seal the edges to finally obtain a degradable dressing patch.

[0035] Example 2:

[0036] A preparation method of a dressing patch, including the following:

[0037] S1: Mix 15 parts of spirulina powder, 15 parts of wakame powder and 80 parts of pure water, carry out mechanical cell disruption by high-speed stirring, control the rotation speed at 10,000 rpm, stir for 15 min until the algal powder is fully dispersed to form a uniform disrupted solution. Adjust the pH of the disrupted solution to 8.0 with a buffer pH agent, add 0.5 part of trypsin and enzymolyze for 5 h, control the temperature at 40 °C to obtain a trypsin enzymolyzed solution, adjust the pH of the trypsin enzymolyzed solution to 7 with a buffer pH agent, add 0.5 part of papain and enzymolyze for 2 h, control the temperature at 60 °C to obtain a double-hydrolysis enzymolyzed solution. Carry out enzyme inactivation treatment on the double-hydrolysis enzymolyzed solution, centrifuge the enzyme-inactivated double-hydrolysis enzymolyzed solution at high speed, take the centrifuged supernatant for ultrafiltration to obtain an ultrafiltered enzymolyzed solution. Freeze-dry the ultrafiltered enzymolyzed solution to obtain an antibacterial polypeptide powder.

[0038] S2: Dissolve 28 parts of Zn(NO3)2·6H2O and 12 parts of Al(NO3)3·9H2O in 240 parts of deionized water a, stir evenly. Under stirring conditions, add 2M NaOH solution dropwise to the solution, adjust the pH to 9.2, keep the reaction temperature at 95°C and reflux for 24 hours. After the reaction is completed, centrifuge to separate the precipitate, and wash it with deionized water multiple times until the pH value of the washing liquid is close to neutral. Dry the washed precipitate at 60°C to obtain Zn / Al-LDH powder. Add the Zn / Al-LDH powder to 200 parts of deionized water b to form an LDH suspension. Add 4 parts of antibacterial polypeptide powder to the LDH suspension and stir at room temperature for 2h for ion exchange loading. During the exchange loading process, control the pH value of the suspension at 7.4. After the loading is completed, filter and dry to obtain Zn / Al-LDH powder loaded with antibacterial polypeptide. Add 22 parts of N-isopropylacrylamide, 1.5 parts of N,N'-methylenebisacrylamide, and 0.25 part of photoinitiator 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylpropiophenone to 220 parts of deionized water c in sequence, stir at a speed of 700 rpm for 40 min to obtain a prepolymer solution. Add the Zn / Al-LDH powder loaded with antibacterial polypeptide to the prepolymer solution, and ultrasonically disperse for 16 min to form a uniform LDH prepolymer suspension. After deoxygenating with nitrogen for 10 min, place the LDH prepolymer suspension in a quartz glass dish and irradiate it with ultraviolet light to initiate polymerization. The wavelength of the ultraviolet light source is 365 nm, and the light intensity is 14 mW / cm 2 , the irradiation time is 13 min, the temperature is controlled at 25°C, and magnetic stirring is carried out at 240 rpm during this period to keep the particles dispersed. After the polymerization is completed, centrifuge, wash, and dry to obtain the LDH composite powder loaded with antibacterial polypeptide.

[0039] S3: Immerse the polylactic acid fiber in a 0.2 mol / L silver nitrate solution, add a 0.5 mol / L sodium citrate solution as a reducing agent, adjust the pH value to 10, control the temperature at 55°C, and react for 60 min to obtain a modified polylactic acid fiber. Then heat-treat the modified polylactic acid fiber, control the temperature at 95°C, and the time is 14 min. Comb the heat-treated modified polylactic acid fiber, and after combing, compound it with silk fibroin fiber through electrospinning technology. The mass ratio of the modified polylactic acid fiber to the silk fibroin fiber is 8:2 to form a uniform nano-silver composite fiber cloth.

[0040] S4: Mix 50 parts of chitosan, 30 parts of citric acid, 15 parts of sodium hyaluronate, 9 parts of carboxymethyl cellulose, 3 parts of tea polyphenols and 240 parts of 1% dilute acid solution evenly, add 12 parts of the LDH composite powder loaded with antibacterial polypeptide prepared in S2, control the temperature at 60 °C, and stir for 60 min to obtain a uniform chitosan cross-linked matrix. Immerse the nano-silver composite fiber cloth prepared in S3 into the chitosan cross-linked matrix with the temperature maintained above 40 °C, so that the chitosan cross-linked matrix uniformly penetrates into the pores of the nano-silver composite fiber cloth to form a composite structure and obtain a dressing layer.

[0041] S5: Lay the spunlace non-woven fabric as the absorption layer on the dressing layer and fix it with hot melt adhesive. Prepare a porous film from polycaprolactone by electrospinning, cover the absorption layer and seal the edges by hot pressing to finally obtain a degradable dressing patch.

[0042] Example 3:

[0043] A preparation method of a dressing patch, including the following steps:

[0044] S1: Mix 12 parts of spirulina powder, 12 parts of wakame powder and 65 parts of pure water, and perform mechanical cell wall breaking by high-speed stirring. Control the rotation speed at 9000 rpm and stir for 12 min until the algal powder is fully dispersed to form a uniform cell wall broken solution. Adjust the pH of the cell wall broken solution to 7.8 with a buffer pH agent, add 0.4 part of trypsin and enzymolyze for 4 h, control the temperature at 38 °C to obtain a trypsin enzymolysis solution. Adjust the pH of the trypsin enzymolysis solution to 6.8 with a buffer pH agent, add 0.3 part of papain and enzymolyze for 3.5 h, control the temperature at 58 °C to obtain a double enzymolysis solution. Perform enzyme inactivation treatment on the double enzymolysis solution, centrifuge the enzyme-inactivated double enzymolysis solution at high speed, and take the centrifuged supernatant for ultrafiltration to obtain an ultrafiltration enzymolysis solution. Freeze-dry the ultrafiltration enzymolysis solution to obtain antibacterial polypeptide powder.

[0045] S2: Dissolve 35 parts of Zn(NO3)2·6H2O and 15 parts of Al(NO3)3·9H2O in 280 parts of deionized water a, stir evenly. Under stirring conditions, add 2M NaOH solution dropwise to the solution, adjust the pH to 9.5, keep the reaction temperature at 95°C and reflux for 24 hours. After the reaction is completed, centrifuge to separate the precipitate, and wash it with deionized water multiple times until the pH value of the washing solution is close to neutral. Dry the washed precipitate at 60°C to obtain Zn / Al-LDH powder. Add the Zn / Al-LDH powder to 230 parts of deionized water b to form an LDH suspension. Add 5 parts of antibacterial polypeptide powder to the LDH suspension, stir at room temperature for 2 h for ion exchange loading. During the exchange loading process, control the pH value of the suspension at 7.2. After the loading is completed, filter and dry to obtain Zn / Al-LDH powder loaded with antibacterial polypeptide. Add 27 parts of N-isopropylacrylamide, 1.8 parts of N,N'-methylenebisacrylamide, and 0.3 parts of photoinitiator 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylpropiophenone to 240 parts of deionized water c in sequence, stir at a speed of 800 rpm for 30 min to obtain a prepolymer solution. Add the Zn / Al-LDH powder loaded with antibacterial polypeptide to the prepolymer solution, ultrasonically disperse for 15 min to form a uniform LDH prepolymer suspension. After deoxygenating with nitrogen for 10 min, place the LDH prepolymer suspension in a quartz glass dish and irradiate it with ultraviolet light to initiate polymerization. The wavelength of the ultraviolet light source is 365 nm, and the light intensity is 15 mW / cm 2 , the irradiation time is 12 min, the temperature is controlled at 25°C, and magnetic stirring is carried out at 200 - 300 rpm during this period to keep the particles dispersed. After the polymerization is completed, centrifuge, wash, and dry to obtain the LDH composite powder loaded with antibacterial polypeptide.

[0046] S3: Immerse the polylactic acid fiber in a 0.15 mol / L silver nitrate solution, add a 0.4 mol / L sodium citrate solution as a reducing agent, adjust the pH value to 9, control the temperature at 48°C, and react for 55 min to obtain a modified polylactic acid fiber. Then heat-treat the modified polylactic acid fiber, control the temperature at 85°C, and the time is 10 min. Card the heat-treated modified polylactic acid fiber, and composite silk fibroin fiber through electrospinning technology after carding. The mass ratio of the modified polylactic acid fiber to the silk fibroin fiber is 8:2 to form a uniform nano-silver composite fiber cloth.

[0047] S4: Mix 45 parts of chitosan, 24 parts of citric acid, 12 parts of sodium hyaluronate, 7.5 parts of carboxymethyl cellulose, 2.5 parts of tea polyphenols and 230 parts of 2% dilute acid solution evenly, add 10 parts of the LDH composite powder loaded with antibacterial polypeptide prepared in S2, control the temperature at 50 °C, and stir for 58 min to obtain a uniform chitosan crosslinked matrix. Immerse the nano-silver composite fiber cloth prepared in S3 into the chitosan crosslinked matrix maintained at a temperature above 40 °C, so that the chitosan crosslinked matrix uniformly penetrates into the pores of the nano-silver composite fiber cloth to form a composite structure and obtain a dressing layer.

[0048] S5: Lay the spunlace non-woven fabric as the absorption layer on the dressing layer and fix it with hot melt adhesive. Prepare a porous film by electrospinning polycaprolactone, cover the absorption layer and hot press the edges to finally obtain a degradable dressing patch.

[0049] Example 4:

[0050] A preparation method of a dressing patch, including the following steps:

[0051] S1: Mix 13 parts of spirulina powder, 13 parts of wakame powder and 72 parts of pure water, and perform mechanical cell wall breaking by high-speed stirring. Control the rotation speed at 8500 rpm and stir for 11 min until the algal powder is fully dispersed to form a uniform cell wall broken solution. Adjust the pH of the cell wall broken solution to 7.6 with a buffer pH agent, add 0.35 part of trypsin and enzymolyze for 3.5 h, control the temperature at 37.5 °C to obtain a trypsin enzymolyzed solution. Adjust the pH of the trypsin enzymolyzed solution to 6.6 with a buffer pH agent, add 0.25 part of papain and enzymolyze for 2.5 h, control the temperature at 56.5 °C to obtain a double-hydrolysis enzymolyzed solution. Perform enzyme inactivation treatment on the double-hydrolysis enzymolyzed solution, centrifuge the enzyme-inactivated double-hydrolysis enzymolyzed solution at high speed, and take the centrifuged supernatant for ultrafiltration to obtain an ultrafiltered enzymolyzed solution. Freeze-dry the ultrafiltered enzymolyzed solution to obtain an antibacterial polypeptide powder.

[0052] S2: Dissolve 28 parts of Zn(NO3)2·6H2O and 15 parts of Al(NO3)3·9H2O in 300 parts of deionized water a, stir evenly. Under stirring conditions, add 2M NaOH solution dropwise to the solution, adjust the pH to 9, keep the reaction temperature at 95 °C and reflux for 24 hours. After the reaction is completed, centrifuge to separate the precipitate, and wash it with deionized water multiple times until the pH value of the washing solution is close to neutral. Dry the washed precipitate at 60 °C to obtain Zn / Al-LDH powder. Add the Zn / Al-LDH powder to 250 parts of deionized water b to form an LDH suspension. Add 5 parts of the antibacterial polypeptide powder to the LDH suspension and stir at room temperature for 2 h for ion exchange loading. During the exchange loading process, control the pH value of the suspension at 7.4. After the loading is completed, filter and dry to obtain the Zn / Al-LDH powder loaded with antibacterial polypeptide. Add 30 parts of N-isopropylacrylamide, 2 parts of N,N'-methylenebisacrylamide, and 0.3 parts of the photoinitiator 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylpropiophenone to 250 parts of deionized water c in sequence, stir at a speed of 600 rpm for 35 min to obtain a prepolymer solution. Add the Zn / Al-LDH powder loaded with antibacterial polypeptide to the prepolymer solution, and ultrasonically disperse for 16 min to form a uniform LDH prepolymer suspension. After deoxidizing with nitrogen for 10 min, place the LDH prepolymer suspension in a quartz glass dish and irradiate it with ultraviolet light to initiate polymerization. The wavelength of the ultraviolet light source is 365 nm, and the light intensity is 12 mW / cm 2 , the irradiation time is 14 min, the temperature is controlled at 25 °C, and magnetic stirring is carried out at 300 rpm during this period to keep the particles dispersed. After the polymerization is completed, centrifuge, wash, and dry to obtain the LDH composite powder loaded with antibacterial polypeptide.

[0053] S3: Immerse the polylactic acid fiber in a 0.18 mol / L silver nitrate solution, add a 0.45 mol / L sodium citrate solution as a reducing agent, adjust the pH value to 8.5, control the temperature at 44 °C, and react for 50 min to obtain a modified polylactic acid fiber. Then heat-treat the modified polylactic acid fiber, control the temperature at 90 °C, and the time is 12 min. Comb the heat-treated modified polylactic acid fiber, and after combing, composite it with silk fibroin fiber by electrospinning technology. The mass ratio of the modified polylactic acid fiber to the silk fibroin fiber is 8:2 to form a uniform nano-silver composite fiber cloth.

[0054] S4: Mix 48 parts of chitosan, 27 parts of citric acid, 10 parts of sodium hyaluronate, 6 parts of carboxymethyl cellulose, 2 parts of tea polyphenols and 210 parts of dilute acid solution evenly, add 9 parts of the LDH composite powder loaded with antibacterial polypeptide prepared in S2, control the temperature at 45 °C, and stir for 57 min to obtain a uniform chitosan crosslinked matrix. Immerse the nano-silver composite fiber cloth prepared in S3 into the chitosan crosslinked matrix maintained at a temperature above 40 °C, so that the chitosan crosslinked matrix uniformly penetrates into the pores of the nano-silver composite fiber cloth to form a composite structure and obtain a dressing layer.

[0055] S5: Lay the spunlace non-woven fabric as the absorption layer on the dressing layer and fix it with hot melt adhesive. Make porous film from polycaprolactone by electrospinning, cover it on the absorption layer and hot press the edges to finally obtain the degradable dressing patch.

[0056] Example 5:

[0057] A preparation method of a dressing patch, including the following steps:

[0058] S1: Mix 14 parts of spirulina powder, 14 parts of wakame powder and 70 parts of pure water, and perform mechanical cell disruption by high-speed stirring at a rotation speed controlled at 8800 rpm for 13 min until the algal powder is fully dispersed to form a uniform disrupted cell liquid. Adjust the pH of the disrupted cell liquid to 7.7 with a buffer pH agent, add 0.38 part of trypsin and enzymolyze for 4.5 h at a temperature controlled at 38.5 °C to obtain a trypsin enzymolyzed liquid. Adjust the pH of the trypsin enzymolyzed liquid to 6.7 with a buffer pH agent, add 0.38 part of papain and enzymolyze for 4 h at a temperature controlled at 57.5 °C to obtain a double-hydrolysis enzymolyzed liquid. Perform enzyme inactivation treatment on the double-hydrolysis enzymolyzed liquid, subject the enzyme-inactivated double-hydrolysis enzymolyzed liquid to high-speed centrifugation, and take the centrifuged supernatant for ultrafiltration to obtain an ultrafiltered enzymolyzed liquid. Freeze-dry the ultrafiltered enzymolyzed liquid to obtain an antibacterial polypeptide powder.

[0059] S2: Dissolve 25 parts of Zn(NO3)2·6H2O and 13 parts of Al(NO3)3·9H2O in 280 parts of deionized water a, stir evenly. Under stirring conditions, add 2M NaOH solution dropwise to the solution, adjust the pH to 9.2, keep the reaction temperature at 95°C and reflux for 24 hours. After the reaction is completed, centrifuge to separate the precipitate, and wash it with deionized water multiple times until the pH value of the washing liquid is close to neutral. Dry the washed precipitate at 60°C to obtain Zn / Al-LDH powder. Add the Zn / Al-LDH powder to 230 parts of deionized water b to form an LDH suspension. Add 3 parts of the antibacterial polypeptide powder to the LDH suspension and stir at room temperature for 2 h for ion exchange loading. During the exchange loading process, control the pH value of the suspension at 7.2. After the loading is completed, filter and dry to obtain the Zn / Al-LDH powder loaded with the antibacterial polypeptide. Add 20 parts of N-isopropylacrylamide, 1 part of N,N'-methylenebisacrylamide, and 0.1 part of the photoinitiator 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylpropiophenone to 200 parts of deionized water c in sequence, stir at a speed of 660 rpm for 33 min to obtain a prepolymer solution. Add the Zn / Al-LDH powder loaded with the antibacterial polypeptide to the prepolymer solution, ultrasonically disperse for 15 min to form a uniform LDH prepolymer suspension. After deoxygenating with nitrogen for 10 min, place the LDH prepolymer suspension in a quartz glass dish and irradiate it with ultraviolet light to initiate polymerization. The wavelength of the ultraviolet light source is 365 nm and the light intensity is 12 mW / cm 2 , the irradiation time is 10 min, control the temperature at 25°C, and stir magnetically at 200 - 300 rpm during this period to keep the particles dispersed. After the polymerization is completed, centrifuge, wash, and dry to obtain the LDH composite powder loaded with the antibacterial polypeptide.

[0060] S3: Immerse the polylactic acid fiber in a 0.17 mol / L silver nitrate solution, add a 0.43 mol / L sodium citrate solution as a reducing agent, adjust the pH value to 8.8, control the temperature at 46°C, and react for 52 min to obtain the modified polylactic acid fiber. Then heat-treat the modified polylactic acid fiber, control the temperature at 92°C and the time at 13 min. Card the heat-treated modified polylactic acid fiber, and after carding, compound silk fibroin fiber through electrospinning technology. The mass ratio of the modified polylactic acid fiber to the silk fibroin fiber is 8:2 to form a uniform nano-silver composite fiber cloth.

[0061] S4: Mix 31 parts of chitosan, 21 parts of citric acid, 12 parts of sodium hyaluronate, 6 parts of carboxymethyl cellulose, 2 parts of tea polyphenols and 180 parts of 1.5% dilute acid solution evenly, add 11 parts of the LDH composite powder loaded with antibacterial polypeptide prepared in S2, control the temperature at 48 °C, and stir for 59 min to obtain a uniform chitosan cross-linked matrix. Immerse the nano-silver composite fiber cloth prepared in S3 into the chitosan cross-linked matrix maintained at a temperature above 40 °C, so that the chitosan cross-linked matrix uniformly penetrates into the pores of the nano-silver composite fiber cloth to form a composite structure, and obtain a dressing layer.

[0062] S5: Lay the spunlace non-woven fabric as the absorbent layer on the dressing layer and fix it with hot melt adhesive. Make a porous film from polycaprolactone by electrospinning, cover the absorbent layer and heat-seal the edges, and finally obtain a degradable dressing patch.

[0063] Comparative Example 1:

[0064] A dressing patch and its preparation method, including the following:

[0065] S1: Dissolve 32 parts of Zn(NO3)2·6H2O and 13 parts of Al(NO3)3·9H2O in 260 parts of deionized water a, stir evenly. Under stirring conditions, add 2M NaOH solution dropwise to the solution, adjust the pH to 9.6, keep the reaction temperature at 95 °C and reflux for 24 hours. After the reaction is completed, centrifuge to separate the precipitate, and wash it with deionized water multiple times until the pH value of the washing solution is close to neutral. Dry the washed precipitate at 60 °C to obtain Zn / Al-LDH powder. Add the Zn / Al-LDH powder to 220 parts of deionized water b to form an LDH suspension. Add 4 parts of antibacterial polypeptide powder to the LDH suspension, stir at room temperature for 2 h for ion exchange loading. During the exchange loading process, control the pH value of the suspension at 7.3. After the loading is completed, filter and dry to obtain the Zn / Al-LDH powder loaded with antibacterial polypeptide. Add 25 parts of N-isopropylacrylamide, 2 parts of N,N'-methylenebisacrylamide, and 0.2 part of photoinitiator 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylpropiophenone to 200 parts of deionized water c in sequence, stir at a speed of 800 rpm for 35 min to obtain a prepolymer solution. Add the Zn / Al-LDH powder loaded with antibacterial polypeptide to the prepolymer solution, ultrasonically disperse for 18 min to form a uniform LDH prepolymer suspension. After deoxygenating with nitrogen for 10 min, place the LDH prepolymer suspension in a quartz glass dish and irradiate it with ultraviolet light to initiate polymerization. The wavelength of the ultraviolet light source is 365 nm, and the light intensity is 12 mW / cm 2 , the irradiation time is 14 min, control the temperature at 25 °C, and stir magnetically at 280 rpm during this period to keep the particles dispersed. After the polymerization is completed, centrifuge, wash, and dry to obtain the LDH composite powder loaded with antibacterial polypeptide.

[0066] S2: Immerse the polylactic acid fiber in a 0.15 mol / L silver nitrate solution, add a 0.4 mol / L sodium citrate solution as a reducing agent, adjust the pH value to 9, control the temperature at 48 °C, react for 50 min to obtain a modified polylactic acid fiber. Then heat-treat the modified polylactic acid fiber, control the temperature at 100 °C for 12 min. Comb the heat-treated modified polylactic acid fiber, and then composite silk fibroin fiber through electrospinning technology. The mass ratio of the modified polylactic acid fiber to the silk fibroin fiber is 8:2 to form a uniform silver nanocomposite fiber cloth.

[0067] S3: Mix 45 parts of chitosan, 21 parts of citric acid, 12 parts of sodium hyaluronate, 3 parts of carboxymethyl cellulose, 1 part of tea polyphenol and 210 parts of a 1.5% dilute acid solution evenly, add 29 parts of the LDH composite powder loaded with antibacterial polypeptide prepared in S2, control the temperature at 50 °C, stir for 55 min to obtain a uniform chitosan cross-linked matrix. Immerse the silver nanocomposite fiber cloth prepared in S3 into the chitosan cross-linked matrix with the temperature maintained above 40 °C, so that the chitosan cross-linked matrix uniformly penetrates into the pores of the silver nanocomposite fiber cloth to form a composite structure and obtain a dressing layer.

[0068] S4: Use a spunlace non-woven fabric as an absorption layer and lay it flat on the dressing layer, and fix it with hot melt adhesive. Make a porous film from polycaprolactone by electrospinning, cover it on the absorption layer and thermally seal the edges to finally obtain a degradable dressing patch.

[0069] Comparative Example 2:

[0070] A preparation method of a dressing patch, including the following steps:

[0071] S1: Mix 12 parts of spirulina powder, 13 parts of wakame powder and 65 parts of pure water, and perform mechanical cell disruption by high-speed stirring at a rotation speed of 8000 rpm for 10 min until the algal powder is fully dispersed to form a uniform disrupted cell liquid. Adjust the pH of the disrupted cell liquid to 7.8 with a buffer pH agent, add 0.4 part of trypsin and enzymolyze for 3 h at a temperature controlled at 36.5 °C to obtain a trypsin enzymolysis solution. Adjust the pH of the trypsin enzymolysis solution to 6.8 with a buffer pH agent, add 0.3 part of papain, and enzymolyze for 3 h at a temperature controlled at 55 °C to obtain a double enzymolysis solution. Inactivate the enzymes in the double enzymolysis solution, centrifuge the enzyme-inactivated double enzymolysis solution at high speed, and take the centrifuged supernatant for ultrafiltration to obtain an ultrafiltered enzymolysis solution. Freeze-dry the ultrafiltered enzymolysis solution to obtain an antibacterial polypeptide powder.

[0072] S2: Dissolve 32 parts of Zn(NO3)2·6H2O and 13 parts of Al(NO3)3·9H2O in 260 parts of deionized water a, stir evenly. Under stirring conditions, dropwise add 2M NaOH solution to the solution, adjust the pH to 9.6, keep the reaction temperature at 95°C and reflux for 24 hours. After the reaction is completed, centrifuge to separate the precipitate, and wash it with deionized water multiple times until the pH value of the washing solution is close to neutral. Dry the washed precipitate at 60°C to obtain Zn / Al-LDH powder. Add the Zn / Al-LDH powder to 220 parts of deionized water b to form an LDH suspension. Add 4 parts of the antibacterial polypeptide powder to the LDH suspension, stir at room temperature for 2 h for ion exchange loading. During the exchange loading process, control the pH value of the suspension at 7.3. After the loading is completed, filter and dry to obtain the Zn / Al-LDH powder loaded with antibacterial polypeptide.

[0073] S3: Immerse the polylactic acid fiber in a 0.15 mol / L silver nitrate solution, add a 0.4 mol / L sodium citrate solution as a reducing agent, adjust the pH value to 9, control the temperature at 48°C, and react for 50 min to obtain the modified polylactic acid fiber. Then heat-treat the modified polylactic acid fiber, control the temperature at 100°C and the time at 12 min. Card the heat-treated modified polylactic acid fiber, and compound silk fibroin fiber through electrospinning technology after carding. The mass ratio of the modified polylactic acid fiber to the silk fibroin fiber is 8:2 to form a uniform nano-silver composite fiber cloth.

[0074] S4: Mix 45 parts of chitosan, 21 parts of citric acid, 12 parts of sodium hyaluronate, 3 parts of carboxymethyl cellulose, 1 part of tea polyphenol and 210 parts of a 1.5% dilute acid solution evenly, add 29 parts of the LDH composite powder loaded with antibacterial polypeptide prepared in S2, control the temperature at 50°C, and stir for 55 min to obtain a uniform chitosan crosslinked matrix. Immerse the nano-silver composite fiber cloth prepared in S3 into the chitosan crosslinked matrix with the temperature maintained above 40°C, so that the chitosan crosslinked matrix uniformly penetrates into the pores of the nano-silver composite fiber cloth to form a composite structure and obtain a dressing layer.

[0075] S5: Use the spunlace non-woven fabric as the absorbent layer and lay it flat on the dressing layer, and fix it with hot melt adhesive. Electrospin polycaprolactone into a porous film, cover it on the absorbent layer and hot-press the edges to finally obtain a degradable dressing patch.

[0076] The dressing patches prepared in the above Examples 1-5 and Comparative Examples 1-2 were subjected to a microbial killing experiment. The activated Escherichia coli, Staphylococcus aureus, and Salmonella typhi were inoculated onto a slant medium and cultured at 36.5 °C for 12 hours. After washing with sterile water and measuring the OD value to ensure the same amount of bacterial strains, the bacterial suspension was evenly spread on a culture medium plate. Filter paper disks with a diameter of 0.6 cm were placed, and the dressing patches of Examples 1-5 and Comparative Examples 1-2 were made into small cylinders of equal thickness using an Oxford cup and placed on the filter paper disks. Three parallel samples were set for each gradient. After culturing in a constant temperature incubator at 36.5 °C for 24 hours, the diameter of the inhibition zone was measured to evaluate the antibacterial performance of the dressing patches. The experimental results are shown in Table 1:

[0077] Table 1

[0078]

[0079]

[0080] The dressing patches prepared in the above Examples 1-5 and Comparative Examples 1-2 were subjected to a water absorption performance test to measure the water absorption ratio, water absorption rate, liquid retention capacity, and water absorption magnification: Approximately 10 ml of physiological saline (0.9% sodium chloride) was placed in a stainless steel container. The test material was cut into test pieces of 4×4 cm, sealed in the container and stored for 8 hours. The weight of the test piece before being put into the container was m1 (g), and the weight of the test piece taken out after 8 hours was m2 (g). The water absorption ratio Q = (m2 - m1) / m1 × 100%: Water absorption rate: 500 μL of physiological saline (0.9% sodium chloride) was dropped on the surface of the test piece, and the time for the liquid to be completely absorbed was measured; Liquid retention capacity: L1 (m1) of physiological saline (0.9% sodium chloride) was placed in a stainless steel container. The test material was cut into test pieces of 7 cm×10 cm×0.1 cm, sealed in the container and stored for 8 hours. After taking out the test piece, the amount of the remaining physiological saline L2 ((m1) was measured. The liquid retention capacity = (L2 - L1) / (7*10*0.1)*10 3 (L / m 3) The experimental results are shown in Table 2:

[0081] Table 2

[0082]

[0083]

[0084] The temperature-responsive release verification tests were carried out on the LDH composite powders loaded with antibacterial polypeptides in Examples 1-5 and the Zn / Al-LDH powder loaded with antibacterial polypeptides prepared in Comparative Example 2. The LDH composite powders loaded with antibacterial polypeptides in Examples 1-5 and the Zn / Al-LDH powder loaded with antibacterial polypeptides prepared in Comparative Example 2 were dispersed in PBS at 1 g / 100 m1, placed in a constant-temperature shaker at a rotation speed of 100 rpm, and operated in the dark. Two groups were set at 25 °C (simulating normal temperature environment) and 36.5 °C (simulating the local temperature rise environment after human infection).

[0085] Sampling time points: 0 h, 1 h, 3 h, 6 h, 12 h, 24 h.

[0086] Operation steps: Each time of sampling, 1 m1 of the suspension was taken, centrifuged (10,000 rpm, 5 min) to separate the supernatant, and the concentration of the antibacterial polypeptide in the supernatant was determined by HPLC method (detection wavelength 280 nm, C18 chromatographic column, mobile phase acetonitrile / water = 30:70, flow rate 1 mL / min), and the cumulative release rate was calculated:

[0087] Cumulative release rate (%) = (release amount at the current time point / total drug loading amount) × 100%

[0088] Table 3: Cumulative release rate of antibacterial polypeptide at 25 °C (%)

[0089] Group 1h 3h 6h 12h 24h Example 1 5.2 10.1 15.3 18.5 20.8 Example 2 4.8 9.5 14.7 17.9 19.6 Example 3 5.0 9.8 15.0 18.2 20.5 Example 4 4.7 9.3 14.5 17.6 19.2 Example 5 4.9 9.6 14.8 17.8 20.0 Comparative Example 2 14.8 27.9 40.5 56.3 73.8

[0090] Table 4: Cumulative release rate of antibacterial polypeptide at 36.5 °C (%)

[0091] Group 1h 3h 6h 12h 24h Example 1 32.5 58.7 78.4 89.2 95.6 Example 2 30.8 55.3 75.1 86.5 93.8 Example 3 31.2 56.9 76.8 87.4 94.5 Example 4 29.7 54.1 74.3 85.2 92.1 Example 5 30.5 55.8 75.6 86.3 93.5 Comparative Example 2 15.0 28.5 41.8 57.4 75.9

[0092] The present invention utilizes the thermosensitivity of PNIPAM to design an intelligent antibacterial polypeptide carrier. At the normal body temperature (36.5 °C) of the human body, the PNIPAM polymer network will contract to release the antibacterial polypeptide carrier. At room temperature (25 °C), the PNIPAM polymer network maintains hydrophilicity and the antibacterial polypeptide carrier is encapsulated, which is convenient for storage and transportation.

[0093] Although the embodiments of the present invention have been shown and described, it will be understood by those of ordinary skill in the art that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present invention, and the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A preparation method of a dressing patch, characterized in that, The dressing patch is composed of an application layer, an absorption layer and a protective layer. The specific steps are as follows: S1: Spirulina powder and kelp powder are mixed with purified water and mechanically broken by high-speed stirring to obtain a broken liquid, which is then hydrolyzed with a dihydrolase, inactivated, centrifuged, ultrafiltered, and freeze-dried to obtain an antibacterial polypeptide powder; S2: Zn(NO3)2·6H2O and Al(NO3)3·9H2O were dissolved in deionized water a, 2M NaOH solution was added dropwise to adjust the pH to 9-10, refluxed at 95°C for 24 hours, centrifuged and washed the precipitate, and dried to obtain Zn / Al-LDH powder. The Zn / Al-LDH powder was mixed with deionized water b to form an LDH suspension, and then antibacterial polypeptide powder was added for ion exchange loading to obtain Zn / Al-LDH powder loaded with antibacterial polypeptide. N-isopropylacrylamide, N,N'-methylenebisacrylamide, and photoinitiator 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylpropiophenone were added to deionized water c in sequence and mixed evenly to form a prepolymer solution. The Zn / Al-LDH powder loaded with antibacterial polypeptide was added to the prepolymer solution, ultrasonically dispersed, and then ultraviolet light was used to initiate polymerization. After the polymerization was completed, centrifuged, washed, and dried to obtain LDH composite powder loaded with antibacterial polypeptide; S3: Immerse the polylactic acid fiber in a silver nitrate solution, add a reducing agent, adjust the pH to 8-10, and react at 40°C-55°C for 45-60 minutes to obtain modified polylactic acid fiber. After heat treatment, the fiber is composited with silk fibroin fiber through electrospinning technology to form a nanosilver composite fiber cloth. S4: chitosan, a cross-linking agent, a moisturizing agent, a thickener, and a dilute acid solution are mixed, and LDH composite powder loaded with antibacterial peptides is added and stirred to form a chitosan cross-linked matrix. The nanosilver composite fiber cloth is immersed in the cross-linked matrix and cooled to form a composite structure to obtain an application layer; S5: Spread the spunlace non-woven fabric as the absorption layer on the patch layer and fix it with hot melt adhesive. Electrospin polycaprolactone into a porous film, cover it on the absorption layer and heat-press and seal the edges to finally produce a degradable dressing.

2. The preparation method of a dressing patch according to claim 1, characterized in that: The pH buffer consists of sodium dihydrogen phosphate and disodium hydrogen phosphate.

3. The preparation method of a dressing patch according to claim 1, characterized in that: The ultrafiltration conditions are as follows: the ultrafiltration pressure is controlled at 0.1-0.5 MPa, and an ultrafiltration membrane with a molecular weight cut-off of 3000-5000 Dalton is selected.

4. The preparation method of a dressing patch according to claim 1, characterized in that: The silver nitrate solution is a 0.1-0.2 mol / L silver nitrate solution.

5. The preparation method of a dressing patch according to claim 1, characterized in that: The reducing agent is a 0.3-0.5 mol / L sodium citrate solution.

6. The preparation method of a dressing patch according to claim 1, characterized in that: The cross-linking agent is citric acid.

7. The preparation method of a dressing patch according to claim 1, characterized in that: The moisturizing agent is sodium hyaluronate.

8. The preparation method of a dressing patch according to claim 1, wherein: The thickener consists of carboxymethyl cellulose and tea polyphenols.

9. The preparation method of a dressing patch according to claim 1, characterized in that: The dihydrolase hydrolysis comprises mixing spirulina powder, kelp powder and purified water, stirring at high speed for mechanical wall breaking, adjusting the pH to 7.5-8.0, adding trypsin for enzymatic hydrolysis; then adjusting the pH to 6.5-7.0, and adding papain for enzymatic hydrolysis.

10. A dressing patch, characterized in that, The dressing is obtained by the preparation method of any one of claims 1 to 8.

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