A hydrogel first-aid patch for burns and scalds, and a preparation method and application thereof

Abstract

The application discloses a hydrogel burn and scald first-aid patch as well as a preparation method and application thereof, and belongs to the field of high polymer medical materials. The hydrogel burn and scald first-aid patch prepared by the application is obtained by encapsulating flexible antibacterial hydrogel material and stretchable cooling hydrogel material after gelation assembly. Compared with the prior art, the hydrogel first-aid patch prepared by the application has excellent cooling, antibacterial and biocompatible properties, and is expected to be applied to burn and scald wound first-aid treatment and further replace traditional dressings to become a new generation of medical dressings.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of high molecular medical materials, in particular to a hydrogel burn and scald first-aid patch and a preparation method and application thereof. BACKGROUND

[0002] In life, traditional burn and scald first-aid measures include water flushing to reduce temperature and relieve pain, cleaning the wound surface; using medicine to kill bacteria and relieve pain, and dressing to reduce postoperative infection, which has problems of limited place, resource waste and secondary injury. The existing dressings mainly use gauze, absorbent cotton and non-woven fabric to dress the wound surface, which faces problems of poor air permeability of the dressing, easy adhesion to the wound and poor patient compliance. Multi-layer structure (CN 208641036 U, CN 114376795B, CN 208693605U), net structure (CN217245184U) and composite structure (CN205286702U) have been applied in the field of medical dressings, but due to the great difference in mechanical properties and heat conduction ability between different materials (such as hydrogel, sponge, foam, gauze and non-woven fabric), mechanical mismatch and heat dissipation problems occur, which are not suitable for burn and scald first-aid.

[0003] Hydrogel is a new type of functional material with a three-dimensional network structure permeated by water. It is widely used in new medical materials due to its good biocompatibility, wet environment maintenance ability, controllable physical properties, drug loading capacity and rich functional groups. A variety of hydrophilic natural polymers or synthetic polymers can form hydrogels through physical (such as electrostatic interaction, hydrogen bonding and hydrophobic interaction) or chemical (such as covalent bond) crosslinking, such as chitosan, hyaluronic acid, polyacrylic acid, polyvinyl alcohol and polyethylene glycol hydrogel. Through multi-level regulation strategies such as molecular engineering, supramolecular chemistry and metamaterial design, the properties of hydrogels and different materials are coordinated and rationally designed. Hydrogels have been widely used in analgesic patches, antipyretic patches, artificial cartilage and drug carriers, so in recent years, the development of hydrogel products with excellent mechanical properties, high antibacterial activity and fast cooling has become a research hotspot. SUMMARY

[0004] The technical problem to be solved by the present application is to provide a hydrogel burn and scald first-aid patch with fast cooling rate, good antibacterial performance and biocompatibility, which can be applied to burn and scald wound first-aid treatment.

[0005] To solve the above technical problems, the technical solutions of the present application are as follows:

[0006] On the one hand, the hydrogel burn and scald first-aid patch provided by the present application is composed of a polyethylene packaging layer, a hydrogel functional layer and a hydrogel base layer.

[0007] Further, the preparation method of the hydrogel functional layer comprises:

[0008] (1) dissolving natural polysaccharide chitosan and its derivatives in a solvent to prepare an antibacterial sol;

[0009] (2) dissolving a stretchable synthetic polymer polyvinyl alcohol in deionized water at high temperature to prepare a polyvinyl alcohol sol;

[0010] (3) mixing the antibacterial sol in step (1) and the polyvinyl alcohol sol in step (2);

[0011] (4) injecting the sol prepared in step (3) into a mold, placing it in a -20°C refrigerator for 8h, then taking it out and thawing it at room temperature for 4h, and repeating the freezing and thawing, to obtain a hydrogel functional layer.

[0012] Further, the preparation method of the hydrogel base layer comprises:

[0013] (11) dissolving natural polysaccharide chitosan and its derivatives in a solvent to obtain an antibacterial sol;

[0014] (12) dissolving a water-absorbable polymer monomer in deionized water to obtain a water-absorbable polymer monomer solution;

[0015] (13) mixing the antibacterial sol in step (11) and the water-absorbable polymer monomer solution in step (12);

[0016] (14) adding an initiator, a crosslinking agent, and a catalyst to the mixed sol prepared in step (13) to perform chemical crosslinking;

[0017] (15) injecting the sol prepared in step (14) into a mold, and curing, to obtain a hydrogel base layer.

[0018] Further, the natural polysaccharide chitosan and its derivatives are any one of chitosan, carboxymethyl chitosan, hydrochloric chitosan, or quaternary ammonium chitosan, the concentration of the antibacterial sol is 2-5 wt.%, the solvent is water or a binary solvent system composed of water and an acidic / alkaline solvent, the mass ratio of the acidic / alkaline solvent to water is 0.006-0.064:1, and the acidic / alkaline solvent is any one of hydrochloric acid (HCl), acetic acid (CH3COOH), sodium hydroxide (NaOH), or potassium hydroxide (KOH).

[0019] Further, in the step (2), the stretchable synthetic polymer polyvinyl alcohol is any one of PVA05-88, PVA17-88 or PVA-124, the polyvinyl alcohol sol concentration is 5-20 wt.%, and the high temperature is 60-90℃; in the step (3), the mass ratio of the antibacterial sol to the polyvinyl alcohol sol is 0.25-2:1, the concentration of the antibacterial sol is preferably 0.4-3.3 wt.%, and the concentration of the polyvinyl alcohol is preferably 1.6-16 wt.%; in the step (4), the cyclic freezing and thawing process is not less than three times.

[0020] Further, in the step (12), the water-absorbable polymer monomer is any one of acrylamide, acrylic acid or N-isopropyl acrylamide, and the water-absorbable polymer monomer solution concentration is 5-30 wt.%; in the step (13), the mass ratio of the antibacterial sol to the water-absorbable polymer monomer solution is 0.25-4:1, the concentration of the antibacterial sol is preferably 0.4-4 wt.%, and the concentration of the water-absorbable polymer monomer is preferably 1-24 wt.%; in the step (14), the initiator is any one or more of ammonium persulfate, potassium persulfate or sodium persulfate, and the concentration is 0.1-0.5 wt.%; the crosslinking agent is N,N'-methylene bisacrylamide, and the concentration is 0.05 wt.%-0.1 wt.%; the catalyst is any one or more of tetramethylethylenediamine or N,N-dimethyl-1,3-propanediamine, and the concentration is 0.02-0.2 vol.%; in the step (15), the curing condition is 25-60℃ for 2-24 h or 10-30 min under ultraviolet light.

[0021] In another aspect, the present application provides a preparation method of the hydrogel burn and scald first-aid patch, and the preparation method comprises:

[0022] (1) placing a precursor sol of a hydrogel functional layer in a mold;

[0023] (2) injecting the mixed sol of the hydrogel base layer prepared in the step (14) into the mold in the step (1) for solidification;

[0024] (3) freeze-drying the hydrogel material solidified in the step (2) and then immersing it in acidic oxidized potential water;

[0025] (4) packaging the hydrogel material after the immersion with polyethylene to obtain the hydrogel burn and scald first-aid patch.

[0026] Further, in the step (3), the freeze-drying condition is a temperature of -80℃, a vacuum degree of <10 Pa and 24 h.

[0027] Further, in the step (3), the immersion time is 24 h at room temperature.

[0028] In still another aspect, the present application provides the hydrogel burn and scald first-aid patch for use in the field of burn and scald wound first-aid treatment.

[0029] The present application has the following beneficial effects:

[0030] In the above scheme, the present application utilizes natural polysaccharide chitosan and stretchable polymer material and high water absorption material to obtain a multi-layer topological structure hydrogel, utilizes the reticular topological structure to realize the increase of specific surface area, thereby optimizing the tensile property of the material, simultaneously accelerating the evaporation of moisture and improving the cooling performance. The obtained hydrogel is pre-soaked in medical disinfectant water (acidic oxidized potential water) and then sealed for storage, to obtain a multifunctional hydrogel burn and scald first-aid patch, which can realize antibiosis, hemostasis, evaporation cooling and shape stability, and is mild and non-irritating to the wound. The flexible hydrogel base realizes antibiosis, hemostasis and easy peeling, the stretchable hydrogel functional layer realizes evaporation heat dissipation, efficient cooling, low-temperature analgesia, good air permeability and shape stability, and the polyethylene packaging layer before use realizes the sealing and water retention of the hydrogel first-aid patch, thereby obtaining a medical multifunctional hydrogel burn and scald first-aid patch. It is expected to replace the traditional first-aid method and become a new generation of medical product. BRIEF DESCRIPTION OF DRAWINGS

[0031] Figure 1 A model diagram of the hydrogel burn and scald first-aid patch of the present application;

[0032] Figure 2 A deformation visual diagram of the hydrogel burn and scald first-aid patch prepared in Example 10 of the present application;

[0033] Figure 3 A stress-strain curve diagram of the hydrogel burn and scald first-aid patch prepared in Example 10 of the present application, the chitosan / polyacrylamide single-layer hydrogel prepared in Comparative Example 1 and the chitosan / polyvinyl alcohol single-layer hydrogel prepared in Comparative Example 4 of the present application;

[0034] Figure 4 A temperature-time change curve diagram of the hydrogel burn and scald first-aid patch prepared in Example 10 of the present application in vitro;

[0035] Figure 5 An antibiosis effect diagram of the hydrogel burn and scald first-aid patch prepared in Example 10 and Example 11 of the present application;

[0036] Figure 6 A cell staining diagram of the hydrogel burn and scald first-aid patch prepared in Example 10 and Example 11 of the present application;

[0037] Figure 7 A secondary scald rat model experiment effect diagram of the hydrogel burn and scald first-aid prepared in Example 10 of the present application. DETAILED DESCRIPTION

[0038] In order to make the technical problems, technical solutions and advantages to be solved by the present application more clear, the following will be described in detail in combination with the drawings and specific embodiments. However, the present application is by no means limited to these examples. The following description is only a better embodiment of the present application, only to explain the present application, and cannot be understood as a limitation on the scope of the patent of the present application. It should be pointed out that any modification, equivalent replacement and improvement made within the spirit and principle of the present application shall be included in the protection scope of the present application.

[0039] Unless otherwise specified, the components used in the present application are commercially available products, and the experimental test conditions have no special instructions, which are the conventional technical operations in the art. The acid electrolyzed water used in the present application is purchased from Panike (brand: China Shenzhen, specification: 2L).

[0040] The present application aims at the problem in the prior art that the mechanical property and heat dissipation performance of the hydrogel dressing are poor and it is not suitable for burn and scald first aid, and provides a hydrogel burn and scald first aid patch and a preparation method and application thereof.

[0041] Example 1

[0042] 1: Preparation of the multifunctional hydrogel base in the hydrogel burn and scald first aid patch, comprising the following steps:

[0043] (1) 5 g of chitosan is dissolved in 95 g of acetic acid (1M) solution to prepare 5 wt.% antibacterial sol;

[0044] (2) 30 g of acrylamide is dissolved in 70 g of deionized water to obtain a uniform 30 wt.% water-absorbable polymer monomer solution;

[0045] (3) The antibacterial sol in the above step (1) and the mixed solution in the above step (2) are mixed to obtain a uniform mixed sol according to a mass ratio of 2:1;

[0046] (4) 0.5 g of ammonium persulfate, 0.1 g of N,N'-methylenebisacrylamide, and 20 μl of tetramethyl ethylenediamine are added to the above mixed sol;

[0047] (5) The above sol is injected into a mold and cured at 25°C for 24 h to obtain a smooth and flat hydrogel base layer;

[0048] 2: Preparation of the hydrogel functional layer in the hydrogel burn and scald first aid patch, comprising the following steps:

[0049] (1) 5 g of chitosan is dissolved in 95 g of sodium hydroxide (1M) solution to prepare 5 wt.% chitosan sol;

[0050] (2) 20 g of polyvinyl alcohol (PVA-124) is dissolved in 80 g of ultrapure water at 90°C to prepare a 20 wt.% polyvinyl alcohol sol;

[0051] (3) Mix the chitosan sol obtained in step (1) with the polyvinyl alcohol sol obtained in step (2) at a mass ratio of 1:1 to obtain a uniform mixed sol.

[0052] (4) Place the above mixed sol in a mold, freeze it in a -20℃ refrigerator for 8 hours, take it out, thaw it at room temperature for 4 hours, and repeat the freeze-thaw process three times to obtain a rectangular hydrogel functional layer of 10cm×10cm.

[0053] 3: The preparation method of the hydrogel burn first aid patch includes the following steps:

[0054] (1) Inject the uncured hydrogel substrate sol solution into a 10cm×10cm rectangular mold placed on the hydrogel functional layer and cure at 25℃ for 24h.

[0055] (2) The above materials were freeze-dried at -80℃ and vacuum degree <10Pa for 24 hours, and then soaked in acidic oxidizing potential water at room temperature for 24 hours.

[0056] (3) The above-soaked hydrogel material is encapsulated with polyethylene upper and lower layers to obtain hydrogel burn first aid patch.

[0057] like Figure 1 The image shown is a model diagram of the hydrogel burn first aid patch prepared according to the present invention, which includes a hydrogel functional layer, a hydrogel base layer, and upper and lower sterile ethylene encapsulation layers.

[0058] Example 2:

[0059] 1: Preparation of the multifunctional hydrogel base for hydrogel burn first aid patches, including the following steps:

[0060] (1) Dissolve 5g of chitosan in 95g of acetic acid (1M) solution to prepare 5wt.% antibacterial sol;

[0061] (2) Dissolve 5g of acrylamide in 95g of deionized water to obtain a uniform 5wt.% water-absorbing polymer monomer solution;

[0062] (3) Mix the antibacterial sol in step (1) with the mixed solution in step (2) at a mass ratio of 1:1 to obtain a uniform mixed sol;

[0063] (4) Add 0.1g potassium persulfate, 0.1g N,N'-methylenebisacrylamide, and 20μl tetramethylethylenediamine to the above mixed sol;

[0064] (5) Inject the above sol into the mold and cure it under ultraviolet light for 30 minutes to obtain a smooth hydrogel base layer;

[0065] 2: Preparation of the functional layer of the hydrogel first-aid patch for burns and scalds, comprising the following steps:

[0066] (1) 2 g of chitosan was dissolved in 98 g of sodium hydroxide (1 M) solution to prepare a 2 wt% chitosan sol;

[0067] (2) 10 g of polyvinyl alcohol (PVA-17-88) was dissolved in 90 g of ultrapure water at 60°C to prepare a 10 wt.% polyvinyl alcohol sol;

[0068] (3) The chitosan sol obtained in step (1) above and the polyvinyl alcohol sol obtained in step (2) were mixed in a mass ratio of 1:1 to obtain a uniform mixed sol;

[0069] (4) The mixed sol was placed in a specially designed mold and frozen in a -20°C refrigerator for 8 h, then thawed at room temperature for 4 h, and the freeze-thaw process was repeated five times to obtain a 10 cm x 10 cm rectangular functional layer of hydrogel.

[0070] 3: Preparation method of the hydrogel first-aid patch for burns and scalds, comprising the following steps:

[0071] (1) The un-solidified hydrogel base sol solution was injected into a 10 cm x 10 cm rectangular mold placed on top of the functional layer of hydrogel and solidified under UV light for 30 min;

[0072] (2) The above material was freeze-dried at -80°C under a vacuum of <10 Pa for 24 h, then immersed in acidic electrolyzed water at room temperature for 24 h.

[0073] (3) The soaked hydrogel material was encapsulated with polyethylene on both sides to obtain the hydrogel first-aid patch for burns and scalds.

[0074] Example 3:

[0075] 1: Preparation of the multifunctional hydrogel base in the hydrogel first-aid patch for burns and scalds, comprising the following steps:

[0076] (1) 2 g of carboxymethyl chitosan was dissolved in 98 g of deionized water to prepare a 2 wt.% antibacterial sol;

[0077] (2) 10 g of acrylic acid was dissolved in 90 g of deionized water to obtain a uniform 10 wt.% water-absorbable polymer monomer solution;

[0078] (3) The antibacterial sol in step (1) above and the mixed solution in step (2) above were mixed in a mass ratio of 2:1 to obtain a uniform mixed sol;

[0079] (4) To the above mixed sol, 0.3 g sodium persulfate, 0.3 g N,N'-methylenebisacrylamide, 10 μl tetramethylethylenediamine were added;

[0080] (5) The above sol was injected into a mold and cured at 60 °C for 4 h to obtain a smooth and flat hydrogel base layer;

[0081] 2: Preparation of the functional layer of the hydrogel burn and scald first-aid patch, comprising the following steps:

[0082] (1) 2 g of chitosan was dissolved in 98 g of potassium hydroxide (0.5 M) solution to prepare a 2 wt% chitosan sol;

[0083] (2) 5 g of polyvinyl alcohol (PVA-05-88) was dissolved in 95 g of ultrapure water at 60 °C to prepare a 5 wt.% polyvinyl alcohol sol;

[0084] (3) The chitosan sol obtained in step (1) and the polyvinyl alcohol sol obtained in step (2) were mixed in a mass ratio of 1:1 to obtain a uniform mixed sol;

[0085] (4) The above mixed sol was placed in a specially designed mold and frozen in a -20 °C refrigerator for 8 h, then thawed at room temperature for 4 h, and the freeze-thaw process was repeated three times to obtain a 10 cm x 10 cm rectangular functional layer of hydrogel.

[0086] 3: Preparation method of the hydrogel burn and scald first-aid patch, comprising the following steps:

[0087] (1) The uncured hydrogel base sol solution was injected into a 10 cm x 10 cm rectangular mold placed on the functional layer of hydrogel, and cured at 60 °C for 4 h;

[0088] (2) The above material was placed in a -80 °C, vacuum degree <10 Pa, and freeze-dried for 24 h, then immersed in acidic oxidizing potential water at room temperature for 24 h.

[0089] (3) The hydrogel material after immersion was encapsulated with polyethylene upper and lower layers to obtain the hydrogel burn and scald first-aid patch.

[0090] Example 4:

[0091] 1: Preparation of the multifunctional hydrogel base in the hydrogel burn and scald first-aid patch, comprising the following steps:

[0092] (1) 5 g of chitosan hydrochloride was dissolved in 95 g of deionized water to prepare a 5 wt.% antibacterial sol;

[0093] (2) 15 g of acrylic acid was dissolved in 85 g of deionized water to obtain a uniform 15 wt.% water-absorbable polymer monomer solution;

[0094] (3) mixing the antibacterial sol of step (1) with the mixed solution of step (2) at a mass ratio of 1:1 to obtain a uniform mixed sol;

[0095] (4) adding 0.4 g of sodium persulfate, 0.2 g of N,N'-methylenebisacrylamide, and 10 μl of tetramethyl ethylenediamine to the mixed sol;

[0096] (5) injecting the sol into a mold and curing at 60°C for 4 h to obtain a smooth and flat hydrogel base layer;

[0097] 2: Preparation of the functional layer of the hydrogel burn and scald first-aid patch, comprising the following steps:

[0098] (1) dissolving 5 g of chitosan in 95 g of a sodium hydroxide (0.5 M) solution at low temperature to prepare a 5 wt.% chitosan sol;

[0099] (2) dissolving 15 g of polyvinyl alcohol (PVA-05-88) in 85 g of ultrapure water at 80°C to prepare a 15 wt.% polyvinyl alcohol sol;

[0100] (3) mixing the chitosan sol obtained in step (1) with the polyvinyl alcohol sol obtained in step (2) at a mass ratio of 1:1 to obtain a uniform mixed sol;

[0101] (4) placing the mixed sol in a specially designed mold, freezing in a -20°C refrigerator for 8 h, then taking it out, thawing at room temperature for 4 h, and repeating the freezing and thawing process three times to obtain a 5 cm x 5 cm rectangular functional layer of hydrogel.

[0102] 3: Preparation method of the hydrogel burn and scald first-aid patch, comprising the following steps:

[0103] (1) injecting the uncured hydrogel base sol solution into a 5 cm x 5 cm rectangular mold placed on the functional layer of hydrogel, and curing at 60°C for 4 h;

[0104] (2) placing the material in a -80°C, vacuum degree <10 Pa environment, freeze-drying for 24 h, and then soaking in acidic electrolyzed water at room temperature for 24 h.

[0105] (3) encapsulating the soaked hydrogel material with polyethylene upper and lower layers to obtain the hydrogel burn and scald first-aid patch.

[0106] Example 5:

[0107] 1: Preparation of the multifunctional hydrogel base in the hydrogel burn and scald first-aid patch, comprising the following steps:

[0108] (1) Dissolve 5 g of quaternary ammonium chitosan in 95 g of deionized water to prepare a 5 wt.% antibacterial sol;

[0109] (2) Dissolve 10 g of acrylamide in 90 g of deionized water to obtain a uniform 10 wt.% water-absorbable polymer monomer solution;

[0110] (3) Mix the antibacterial sol in step (1) above with the mixed solution in step (2) above at a mass ratio of 0.5:1 to obtain a uniform mixed sol;

[0111] (4) Add 0.3 g of sodium persulfate, 0.3 g of N,N'-methylenebisacrylamide, and 10 μl of tetramethyl ethylenediamine to the mixed sol above;

[0112] (5) Inject the sol above into a mold and cure at 60°C for 2 h to obtain a flat and smooth hydrogel base layer;

[0113] 2: Preparation of a functional layer of a hydrogel burn and scald first-aid patch, comprising the following steps:

[0114] (1) Dissolve 2 g of chitosan in 98 g of hydrochloric acid (0.5 M) solution at low temperature to prepare a 2 wt.% chitosan sol;

[0115] (2) Dissolve 10 g of polyvinyl alcohol (PVA-05-88) in 90 g of ultrapure water at 90°C to prepare a 10 wt.% polyvinyl alcohol sol;

[0116] (3) Mix the chitosan sol obtained in step (1) above with the polyvinyl alcohol sol obtained in step (2) above at a mass ratio of 1:1 to obtain a uniform mixed sol;

[0117] (4) Place the mixed sol above in a specially designed mold, freeze in a -20°C refrigerator for 8 h, then take it out, thaw at room temperature for 4 h, and repeat the freezing and thawing process three times to obtain a 5 cm x 5 cm rectangular functional layer of hydrogel.

[0118] 3: Preparation method of a hydrogel burn and scald first-aid patch, comprising the following steps:

[0119] (1) Inject the unhardened hydrogel base sol solution into a 5 cm x 5 cm rectangular mold, and place it on top of the unhardened functional layer of hydrogel after curing at 60°C for 2 h;

[0120] (2) Freeze dry the above material at -80°C and a vacuum degree of <10 Pa for 24 h, and then immerse it in acidic electrolytic water at room temperature for 24 h.

[0121] (3) Encapsulate the immersed hydrogel material with polyethylene on the top and bottom layers to obtain a hydrogel burn and scald first-aid patch.

[0122] Example 6:

[0123] 1: Preparation of multifunctional hydrogel base in hydrogel first-aid patch for burns and scalds, comprising the following steps:

[0124] (1) Dissolve 5 g of carboxymethyl chitosan in 95 g of deionized water to prepare a 5 wt.% antibacterial sol;

[0125] (2) Dissolve 10 g of N-isopropyl acrylamide in 90 g of deionized water to obtain a uniform 10 wt.% water-absorbable polymer monomer solution;

[0126] (3) Mix the antibacterial sol in step (1) above and the mixed solution in step (2) above in a mass ratio of 1:1 to obtain a uniform mixed sol;

[0127] (4) Add 0.2 g of ammonium persulfate, 0.3 g of N,N'-methylenebisacrylamide, and 2 μl of tetramethyl ethylenediamine to the mixed sol above;

[0128] (5) Inject the sol above into a mold and solidify at 37°C for 6 h to obtain a smooth and flat hydrogel base layer;

[0129] 2: Preparation of hydrogel functional layer in hydrogel first-aid patch for burns and scalds, comprising the following steps:

[0130] (1) Dissolve 5 g of chitosan in 95 g of acetic acid (0.5 M) solution to prepare a 5 wt.% chitosan sol;

[0131] (2) Dissolve 10 g of polyvinyl alcohol (PVA-124) at 80°C in 90 g of ultrapure water to prepare a 10 wt.% polyvinyl alcohol sol;

[0132] (3) Mix the chitosan sol obtained in step (1) above and the polyvinyl alcohol sol obtained in step (2) in a mass ratio of 1:1 to obtain a uniform mixed sol;

[0133] (4) Place the mixed sol above in a specially designed mold, freeze it in a -20°C refrigerator for 8 h, then take it out, thaw it at room temperature for 4 h, and repeat the freeze-thaw process three times to obtain an 8 cm x 6 cm rectangular hydrogel functional layer.

[0134] 3: Preparation method of hydrogel first-aid patch for burns and scalds, comprising the following steps:

[0135] (1) Inject the hydrogel base sol solution without solidification treatment into an 8 cm x 6 cm rectangular mold, and place it on top of the un-solidified hydrogel functional layer after solidifying at 37°C for 6 h;

[0136] (2) The above material is placed at -80°C, vacuum degree <10 Pa, and freeze-dried for 24 h, and then immersed in acidic oxidizing potential water at room temperature for 24 h.

[0137] (3) The above soaked hydrogel material is encapsulated with polyethylene on the top and bottom, and the hydrogel burn and scald first-aid patch is obtained.

[0138] Example 7:

[0139] 1: Preparation of the multifunctional hydrogel base in the hydrogel burn and scald first-aid patch, comprising the following steps:

[0140] (1) 4 g of carboxymethyl chitosan is dissolved in 96 g of deionized water to prepare an antibacterial sol of 4 wt.%;

[0141] (2) 15 g of N-isopropyl acrylamide is dissolved in 85 g of deionized water to obtain a uniform 15 wt.% water-absorbable polymer monomer solution;

[0142] (3) The antibacterial sol in the above step (1) and the mixed solution in the above step (2) are mixed to obtain a uniform mixed sol according to a mass ratio of 1:1;

[0143] (4) 0.15 g of sodium persulfate, 0.15 g of N,N'-methylene bisacrylamide, and 100 μl of tetramethyl ethylenediamine are added to the above mixed sol;

[0144] (5) The above sol is injected into a mold and cured at 25°C for 24 h to obtain a smooth and flat hydrogel base layer;

[0145] 2: Preparation of the hydrogel functional layer in the hydrogel burn and scald first-aid patch, comprising the following steps:

[0146] (1) 4 g of chitosan is dissolved in 96 g of acetic acid (0.5 M) solution to prepare a chitosan sol of 4 wt.%;

[0147] (2) 5 g of polyvinyl alcohol (PVA-17-88) is dissolved in 95 g of ultrapure water at 90°C to prepare a polyvinyl alcohol sol of 5 wt.%;

[0148] (3) The chitosan sol obtained in the above step (1) and the polyvinyl alcohol sol obtained in step (2) are mixed according to a mass ratio of 1:1 to obtain a uniform mixed sol;

[0149] (4) The above mixed sol is placed in a mold, taken out after being frozen in a -20°C refrigerator for 8 h, thawed at room temperature for 4 h, and the freeze-thaw process is repeated five times to obtain a 10 cm x 10 cm mesh-shaped hydrogel functional layer.

[0150] 3: Preparation method of the hydrogel burn and scald first-aid patch, comprising the following steps:

[0151] (1) The uncured hydrogel base sol solution was injected into a 10 cm x 10 cm rectangular mold, and after curing at 25°C for 24 h, it was placed on top of the uncured hydrogel functional layer

[0152] (2) The above material was placed in a vacuum at -80°C with a vacuum degree < 10 Pa, and after freeze-drying for 24 h, it was immersed in acidic oxidizing potential water at room temperature for 24 h.

[0153] (3) The above soaked hydrogel material was encapsulated with polyethylene on both sides to obtain the hydrogel burn and scald first-aid patch.

[0154] Example 8:

[0155] 1: Preparation of the multifunctional hydrogel base in the hydrogel burn and scald first-aid patch, including the following steps:

[0156] (1) 5 g of hydrochloric chitosan was dissolved in 95 g of deionized water to prepare a 5 wt.% antibacterial sol;

[0157] (2) 20 g of N-isopropyl acrylamide was dissolved in 80 g of deionized water to obtain a uniform 20 wt.% water-absorbable polymer monomer solution;

[0158] (3) The antibacterial sol in step (1) above and the mixed solution in step (2) above were mixed to obtain a uniform mixed sol with a mass ratio of 1:1;

[0159] (4) 0.5 g of ammonium persulfate, 0.05 g of N,N'-methylene bisacrylamide, and 200 μl of tetramethyl ethylenediamine were added to the above mixed sol;

[0160] (5) The above sol was injected into a mold and cured at 37°C for 12 h to obtain a smooth and flat hydrogel base layer;

[0161] 2: Preparation of the hydrogel functional layer in the hydrogel burn and scald first-aid patch, including the following steps:

[0162] (1) 4 g of quaternary ammonium chitosan was dissolved in 96 g of deionized water solution to prepare a 4 wt.% chitosan sol;

[0163] (2) 5 g of polyvinyl alcohol (PVA-05-88) was dissolved in 95 g of ultrapure water at 90°C to prepare a 5 wt.% polyvinyl alcohol sol;

[0164] (3) The chitosan sol obtained in step (1) above and the polyvinyl alcohol sol obtained in step (2) were mixed with a mass ratio of 1:1 to obtain a uniform mixed sol;

[0165] (4) The mixed sol is placed in a special mold, frozen in a refrigerator at -20°C for 8h, then taken out, thawed at room temperature for 4h, and the freeze-thaw process is cycled five times to obtain a 10cm x 10cm network hydrogel functional layer.

[0166] 3: Preparation method of hydrogel burn and scald first-aid patch, comprising the following steps:

[0167] (1) The un-solidified hydrogel base sol solution is injected into a 10cm x 10cm rectangular mold, and then placed on the un-solidified hydrogel functional layer after being solidified at 37°C for 12h;

[0168] (2) The above material is placed in a vacuum condition at -80°C and a vacuum degree <10Pa, and then freeze-dried for 24h, and then immersed in acidic oxidizing potential water at room temperature for 24h.

[0169] (3) The hydrogel material after immersion is encapsulated with polyethylene upper and lower layers to obtain the hydrogel burn and scald first-aid patch.

[0170] Example 9:

[0171] 1: Preparation of multifunctional hydrogel base in hydrogel burn and scald first-aid patch, comprising the following steps:

[0172] (1) 4g of chitosan is dissolved in 96g of acetic acid (0.8M) solution to prepare a 4wt.% antibacterial sol;

[0173] (2) 10g of acrylamide is dissolved in 90g of deionized water to obtain a uniform 10wt.% water-absorbable polymer monomer solution;

[0174] (3) The antibacterial sol in step (1) and the mixed solution in step (2) are mixed to obtain a uniform mixed sol according to a mass ratio of 1:1;

[0175] (4) 0.15g of sodium persulfate, 0.15g of N,N'-methylenebisacrylamide, and 100μl of N,N'-dimethyl-1,3-propanediamine are added to the above mixed sol;

[0176] (5) The sol is injected into a mold and solidified at 25°C for 24h to obtain a smooth hydrogel base layer;

[0177] 2: Preparation of hydrogel functional layer in hydrogel burn and scald first-aid patch, comprising the following steps:

[0178] (1) 4g of chitosan is dissolved in 96g of acetic acid (0.8M) solution to prepare a 4wt% chitosan sol;

[0179] (2) 15 g of polyvinyl alcohol (PVA-17-88) was dissolved in 95 g of ultrapure water at 90°C to prepare a 15 wt.% polyvinyl alcohol sol;

[0180] (3) The chitosan sol obtained in step (1) above was mixed with the polyvinyl alcohol sol obtained in step (2) above at a mass ratio of 0.5:1 to obtain a uniform mixed sol;

[0181] (4) The mixed sol above was placed in a specially designed mold, taken out after being frozen in a -20°C refrigerator for 8 h, thawed at room temperature for 4 h, and the freezing and thawing process was repeated three times to obtain a 10 cm x 10 cm network hydrogel functional layer.

[0182] 3: Preparation method of hydrogel burn first-aid patch, comprising the following steps:

[0183] (1) The un-solidified hydrogel base sol solution was injected into a 10 cm x 10 cm rectangular mold placed in the hydrogel functional layer and solidified at 25°C for 24 h;

[0184] (2) The above material was placed in a -80°C, vacuum degree <10 Pa condition, 24 h freeze-dried, and then placed in an acidic oxidative potential water at room temperature for 24 h.

[0185] (3) The hydrogel material after soaking was packaged with polyethylene upper and lower layers to obtain the hydrogel burn first-aid patch.

[0186] Example 10:

[0187] 1: Preparation of multifunctional hydrogel base in hydrogel burn first-aid patch, comprising the following steps:

[0188] (1) 5 g of chitosan was dissolved in 95 g of acetic acid (1 M) solution to prepare a 5 wt.% antibacterial sol;

[0189] (2) 25 g of acrylamide was dissolved in 75 g of deionized water to obtain a uniform 25 wt.% water-absorbable polymer monomer solution;

[0190] (3) The antibacterial sol in step (1) above was mixed with the mixed solution in step (2) above at a mass ratio of 1:1 to obtain a uniform mixed sol;

[0191] (4) 0.1 g of sodium persulfate, 0.2 g of N,N'-methylenebisacrylamide, and 8 μl of tetramethyl ethylenediamine were added to the mixed sol above;

[0192] (5) The sol above was injected into a mold and solidified at 60°C for 4 h to obtain a smooth and flat hydrogel base layer;

[0193] 2: Preparation of the hydrogel functional layer in the hydrogel burn first aid patch, including the following steps:

[0194] (1) Dissolve 5g of chitosan in 95g of acetic acid (1M) solution to prepare 5wt% chitosan sol;

[0195] (2) Dissolve 20g of polyvinyl alcohol (PVA-124) in 80g of ultrapure water at 90℃ to prepare a 20wt.% polyvinyl alcohol sol;

[0196] (3) Mix the chitosan sol obtained in step (1) with the polyvinyl alcohol sol obtained in step (2) at a mass ratio of 1:1 to obtain a uniform mixed sol.

[0197] (4) Place the above mixed sol in a special mold, freeze it in a -20℃ refrigerator for 8 hours, take it out, thaw it at room temperature for 4 hours, and repeat the freeze-thaw process three times to obtain a 4cm×3cm network hydrogel functional layer.

[0198] 3: The preparation method of the hydrogel burn first aid patch includes the following steps:

[0199] (1) Inject the uncured hydrogel substrate sol solution into a rectangular mold of 4cm×3cm, cure it at 60℃ for 4h, and then place it on the uncured hydrogel functional layer.

[0200] (2) The above materials were freeze-dried at -80℃ and vacuum degree <10Pa for 24 hours, and then soaked in acidic oxidizing potential water at room temperature for 24 hours.

[0201] (3) The above-soaked hydrogel material is encapsulated with polyethylene upper and lower layers to obtain hydrogel burn first aid patch.

[0202] like Figure 2 The image shown is a visual representation of the deformation of the hydrogel burn first aid patch prepared in Example 10 of this invention, including FBP images of the patch under 0%, 50%, and 100% strain. The hydrogel burn first aid patch prepared in this invention will only tear under a strain of 70%.

[0203] Example 11:

[0204] 1: Preparation of the multifunctional hydrogel base for hydrogel burn first aid patches, including the following steps:

[0205] (1) Dissolve 5g of chitosan in 95g of acetic acid (1M) solution to prepare 5wt.% antibacterial sol;

[0206] (2) Dissolve 25g of acrylamide in 75g of deionized water to obtain a uniform 25wt.% water-absorbing polymer monomer solution;

[0207] (3) mixing the antibacterial sol of step (1) and the mixed solution of step (2) to obtain a uniform mixed sol;

[0208] (4) adding 0.1 g of sodium persulfate, 0.2 g of N,N'-methylenebisacrylamide, and 8 μl of tetramethyl ethylenediamine to the mixed sol;

[0209] (5) injecting the sol into a mold and curing at 60°C for 4 h to obtain a smooth and flat hydrogel base layer;

[0210] 2: Preparation of the hydrogel functional layer in the hydrogel burn and scald first-aid patch, comprising the following steps:

[0211] (1) dissolving 5 g of chitosan in 95 g of acetic acid (1M) solution to prepare a 5 wt.% chitosan sol;

[0212] (2) dissolving 20 g of polyvinyl alcohol (PVA-124) in 80 g of ultrapure water at 90°C to prepare a 20 wt.% polyvinyl alcohol sol;

[0213] (3) mixing the chitosan sol obtained in step (1) and the polyvinyl alcohol sol obtained in step (2) at a mass ratio of 1:1 to obtain a uniform mixed sol;

[0214] (4) placing the mixed sol in a specially designed mold, freezing in a -20°C refrigerator for 8 h, then taking it out, thawing at room temperature for 4 h, and repeating the freezing and thawing process three times to obtain a 4 cm x 3 cm mesh-shaped hydrogel functional layer.

[0215] 3: Preparation method of the hydrogel burn and scald first-aid patch, comprising the following steps:

[0216] (1) injecting the non-cured hydrogel base sol solution into a 4 cm x 3 cm rectangular mold, and placing it on the non-cured hydrogel functional layer after curing at 60°C for 4 h;

[0217] (2) placing the material in a -80°C, vacuum degree <10 Pa environment, freeze-drying for 24 h, and then soaking in pure water at room temperature for 24 h.

[0218] (3) packaging the soaked hydrogel material with polyethylene on the top and bottom to obtain the hydrogel burn and scald first-aid patch.

[0219] The inventors have conducted many experiments to find that the flexible antibacterial hydrogel material and the stretchable and cooling hydrogel material assembled and packaged after gelation exhibit excellent cooling, antibacterial performance, and biocompatibility, and can be used as a medical hydrogel burn and scald first-aid patch. In order to further illustrate the beneficial effects achieved by the present application, the following comparative examples are set up based on Example 10.

[0220] Comparative Example 1

[0221] The preparation method of the hydrogel burn and scald first-aid patch comprises the following steps:

[0222] (1) 5 g of chitosan is dissolved in 95 g of acetic acid (1 M) solution to prepare 5 wt.% antibacterial sol;

[0223] (2) 25 g of acrylamide is dissolved in 75 g of deionized water to obtain a uniform 25 wt.% water-absorbable polymer monomer solution;

[0224] (3) The antibacterial sol in the above step (1) and the mixed solution in the above step (2) are mixed to obtain a uniform mixed sol according to a mass ratio of 1:1;

[0225] (4) 0.1 g of sodium persulfate, 0.2 g of N,N'-methylene bisacrylamide, and 8 μl of tetramethyl ethylenediamine are added to the mixed sol;

[0226] (5) The sol is injected into a mold and cured at 60°C for 4 h to obtain a smooth hydrogel base layer;

[0227] (6) The material is placed in a vacuum degree <10 Pa condition at -80°C, and after 24 h of freeze-drying, it is immersed in acidic oxidizing potential water for 24 h;

[0228] (7) The hydrogel material after immersion is packaged with polyethylene on the upper and lower layers to obtain a hydrogel burn and scald first-aid patch.

[0229] Comparative Example 2

[0230] The preparation method of the hydrogel burn and scald first-aid patch comprises the following steps:

[0231] (1) 5 g of carboxymethyl chitosan is dissolved in 95 g of acetic acid (1 M) solution to prepare 5 wt.% antibacterial sol;

[0232] (2) 25 g of acrylamide is dissolved in 75 g of deionized water to obtain a uniform 25 wt.% water-absorbable polymer monomer solution;

[0233] (3) The antibacterial sol in the above step (1) and the mixed solution in the above step (2) are mixed to obtain a uniform mixed sol according to a mass ratio of 1:1;

[0234] (4) 0.1 g of sodium persulfate, 0.2 g of N,N'-methylene bisacrylamide, and 8 μl of tetramethyl ethylenediamine are added to the mixed sol;

[0235] (5) The sol is injected into a mold and cured at 60°C for 4 h to obtain a smooth hydrogel base layer;

[0236] (6) The above material is placed in a vacuum degree <10 Pa condition at -80°C, freeze-dried for 24h, and then soaked in acidic oxidizing potential water for 24h;

[0237] (7) The soaked hydrogel material is packaged with polyethylene on the upper and lower layers to obtain the hydrogel burn and scald first-aid patch.

[0238] Comparative Example 3

[0239] The preparation method of the hydrogel burn and scald first-aid patch comprises the following steps:

[0240] (1) 5g of quaternary ammonium chitosan is dissolved in 95g of acetic acid (1M) solution to prepare a 5wt.% antibacterial sol;

[0241] (2) 25g of acrylamide is dissolved in 75g of deionized water to obtain a uniform 25wt.% water-absorbable polymer monomer solution;

[0242] (3) The antibacterial sol in the above step (1) and the mixed solution in the above step (2) are mixed to obtain a uniform mixed sol according to a mass ratio of 1:1;

[0243] (4) 0.1g of sodium persulfate, 0.2g of N,N'-methylene bisacrylamide, and 8μl of tetramethyl ethylenediamine are added to the above mixed sol;

[0244] (5) The sol is injected into a mold and cured at 60°C for 4h to obtain a smooth hydrogel base layer;

[0245] (6) The above material is placed in a vacuum degree <10 Pa condition at -80°C, freeze-dried for 24h, and then soaked in acidic oxidizing potential water for 24h;

[0246] (7) The soaked hydrogel material is packaged with polyethylene on the upper and lower layers to obtain the hydrogel burn and scald first-aid patch.

[0247] Comparative Example 4

[0248] The preparation method of the hydrogel burn and scald first-aid patch comprises the following steps:

[0249] (1) 5g of chitosan is dissolved in 95g of acetic acid (1M) solution to prepare a 5wt.% chitosan sol;

[0250] (2) 20g of polyvinyl alcohol (PVA-124) is dissolved in 80g of ultrapure water at 90°C to prepare a 20wt.% polyvinyl alcohol sol;

[0251] (3) The chitosan sol obtained in the above step (1) and the polyvinyl alcohol sol obtained in step (2) are mixed according to a mass ratio of 1:1 to obtain a uniform mixed sol;

[0252] (4) The mixed sol is placed in a special mold, taken out after being frozen in a refrigerator at -20°C for 8 h, thawed at room temperature for 4 h, and the freezing and thawing process is repeated three times to obtain a 4 cm x 3 cm network hydrogel functional layer.

[0253] (5) The sol is injected into the mold and cured at 60°C for 4 h to obtain a smooth hydrogel base layer;

[0254] (6) The material is placed in a vacuum at -80°C with a vacuum degree of less than 10 Pa, freeze-dried for 24 h, and then soaked in acidic oxidizing potential water for 24 h;

[0255] (7) The soaked hydrogel material is packaged with polyethylene on the top and bottom to obtain a hydrogel burn and scald first-aid patch.

[0256] Comparative Example 5

[0257] The preparation method of the hydrogel burn and scald first-aid patch comprises the following steps:

[0258] (1) 5 g of chitosan is dissolved in 95 g of acetic acid (1M) solution to prepare a 5 wt.% antibacterial sol;

[0259] (2) 25 g of N-isopropyl acrylamide is dissolved in 75 g of deionized water to obtain a uniform 25 wt.% water-absorbable polymer monomer solution;

[0260] (3) The antibacterial sol in step (1) and the mixed solution in step (2) are mixed to obtain a uniform mixed sol with a mass ratio of 1:1;

[0261] (4) 0.1 g of sodium persulfate, 0.2 g of N,N'-methylene bisacrylamide, and 8 μl of tetramethyl ethylenediamine are added to the mixed sol;

[0262] (5) The sol is injected into the mold and cured at 60°C for 4 h to obtain a smooth hydrogel base layer;

[0263] (6) The material is placed in a vacuum at -80°C with a vacuum degree of less than 10 Pa, freeze-dried for 24 h, and then soaked in acidic oxidizing potential water for 24 h;

[0264] (7) The soaked hydrogel material is packaged with polyethylene on the top and bottom to obtain a hydrogel burn and scald first-aid patch.

[0265] Comparative Example 6

[0266] The preparation method of the hydrogel burn and scald first-aid patch comprises the following steps:

[0267] (1) 5 g of chitosan is dissolved in 95 g of acetic acid (1M) solution to prepare a 5 wt.% antibacterial sol;

[0268] (2) 25 g of acrylic acid was dissolved in 75 g of deionized water to obtain a uniform 25 wt.% water-absorbable polymer monomer solution;

[0269] (3) The antibacterial sol of step (1) above and the mixed solution of step (2) above were mixed at a mass ratio of 1:1 to obtain a uniform mixed sol;

[0270] (4) 0.1 g of sodium persulfate, 0.2 g of N,N'-methylenebisacrylamide, and 8 μl of tetramethyl ethylenediamine were added to the mixed sol above;

[0271] (5) The sol above was injected into a mold and cured at 60°C for 4 h to obtain a smooth and flat hydrogel base layer;

[0272] (6) The material above was placed in a vacuum condition of <10 Pa at -80°C for 24 h, and then immersed in acidic electrolyzed water after freeze-drying;

[0273] (7) The hydrogel material after immersion was packaged with polyethylene on the top and bottom to obtain a hydrogel burn and scald first-aid patch.

[0274] It should be noted that the polyethylene top and bottom packaging in the present application is only for product commercialization and convenient storage. The performance data of the hydrogel burn and scald first-aid patches prepared in Examples 1-11 and Comparative Examples 1-6 (all without polyethylene top and bottom packaging) are shown in Table 1 below:

[0275] The antibacterial performance determination method is based on the American Society for Testing and Materials standard "ASTM E2149 Test Method for Determining the Antimicrobial Activity of Immobilized Antimicrobial Agents Under Dynamic Contact Conditions", and 1 x 10 5 CFU / mL of initial concentration of Staphylococcus aureus (gram-positive bacteria) or Escherichia coli (gram-negative bacteria) was cultured for a total of 22 h at 28°C and 160 rpm by the shaking flask method to determine the bacteriostatic effect of the deionized water-swollen hydrogel burn and scald first-aid patch (FBP-D) of Example 11 and the acidic electrolyzed water-swollen hydrogel burn and scald first-aid patch (FBP) of Examples 1-10 in vitro.

[0276] The cooling performance determination method is to prove the subcutaneous temperature reduction of the rabbit skin after burn and scald by monitoring the temperature data recorder (SIN-5000C, sinmeasure). Before the experiment, the full layer skin tissue of New Zealand white rabbits (1.7-2.2 kg, Ganzhou Livestock Institute) is taken, the temperature sensor is installed at the bottom, and after being preheated by 90 DEG C hot water bath for 7-10 s, the rabbit skin after burn and scald is quickly placed on the polystyrene foam plastic for heat preservation, and the water gel burn and scald first-aid patch is applied on the surface, and the cooling condition within 120 s is recorded (n=3). The burn and scald rabbit skin without first-aid treatment is taken as a blank group.

[0277] Table 1

[0278]

[0279]

[0280] From the data in the above table, the natural polysaccharide chitosan is compounded with the stretchable polymer material and the superabsorbent material to obtain the multi-layer topological structure water gel, the specific surface area is increased by using the reticular topological structure, so that the tensile property of the material is optimized, the antibacterial effect is good, the water gel prepared in the application can accelerate water evaporation, improve the cooling performance, can play a role in rapidly reducing the body surface temperature of the patient, and effectively reduces the tissue damage and inflammation level by reducing edema formation and improving the collagen / vascular ratio.

[0281] As shown in Figure 5 Figure 2, the antibacterial effect diagram of the water gel burn and scald first-aid patch prepared in example 10 of the application. a is the direct image of the corresponding colony forming unit (CFU) after the experiment (20 μL, 10 5 fold dilution, incubated on LB agar plate for 24 h, n=6) of different co-cultured bacteria liquid, that is, staphylococcus aureus or escherichia coli (1x10 -4 CFU / mL). Sample: sterile water (negative control group), acidic oxidation potential water (positive control group / EO Water), water-swollen water gel burn and scald first-aid patch (D-FBP, example 11) and acidic oxidation potential water-swollen water gel burn and scald first-aid patch (FBP, example 10). b is the corresponding optical density (OD600) at 600 nm of different co-cultured bacteria liquid (2 ml / well, n=6). The water gel swollen by acidic oxidation potential water has the best effect on inhibiting the growth of pathogenic bacteria.

[0282] Due to the limitation of length, only the in-vitro temperature-time change curve diagram of the in-vitro rabbit skin simulation cooling experiment test result of the water gel burn and scald first-aid patch prepared in example 10 is provided, and the result is as shown in Figure 4As shown, the temperature of the hydrogel burn and scald first-aid patch prepared in Example 10 of the present application decreased significantly faster, which is beneficial to the recovery of the body temperature of the burn and scald patient in practical application.

[0283] As shown in the following table, a series of biological related experiments were carried out using the optimal Example 10 as an example, and the experimental results are shown in the following table. Figure 3 Figures 6-7

[0284] Tensile property determination of the hydrogel burn and scald first-aid patch

[0285] The mechanical properties of the hydrogel burn and scald first-aid patch prepared in Example 10 of the present application (without using polyethylene upper and lower layer packaging), the chitosan / polyacrylamide single-layer hydrogel prepared in Comparative Example 1 and the chitosan / polyvinyl alcohol single-layer hydrogel prepared in Comparative Example 4 were tested by the inventor according to GB 13022-91 Plastic Film Tensile Property Test Method using a universal mechanical testing machine (ZQ-990LB, 5N, Zhiqu Precision Instruments). As shown in the following table, the strain of the chitosan / polyacrylamide single-layer hydrogel was 43%, and the strain of the chitosan / polyvinyl alcohol single-layer hydrogel was 158%. The structure of the present application can effectively realize the optimization of the tensile property, and the strain of the hydrogel burn and scald first-aid patch prepared in the present application is more than 106%. Figure 3

[0286] HFF-1 cell culture test

[0287] Figure 6 Cell staining diagram of the hydrogel burn and scald first-aid patch prepared in Examples 10 and 11 of the present application. After the water-swellable hydrogel burn and scald first-aid patch (D-FBP, i.e. Example 11) and the acid-oxidized potential water-swellable hydrogel burn and scald first-aid patch (FBP, Example 10) (20 mg / mL, n=3) were co-cultured with HFF-1 cells for 24 h and 48 h, AO / EB double fluorescent dye staining was used, and the scale is 100 μm. The hydrogel burn and scald first-aid patch prepared using acid-oxidized potential water in the present application has excellent cell compatibility with HFF-1 cells.

[0288] Histological analysis

[0289] The experimental method is as follows: a secondary scald model is established on the back of an SD rat (about 400 g, male), and the in-vivo cooling performance and treatment effect of FBP are observed. All operations are carried out under sterile conditions (temperature: 18-26℃, humidity: 30%-70%). After the SD rat is anesthetized by intraperitoneal injection of 1% sodium pentobarbital, the back of the SD rat is shaved. In order to establish a second-degree scald model, a copper sheet (1.5×1.5×0.3 cm 3 ​​​Rats were immersed in a 90°C hot water bath for 5 minutes, and then a heated copper sheet was applied to the rat's back skin for 7 seconds. Hydrogel burn first aid patches (FBP) were applied immediately to treat the burns. Untreated rats served as a control to exclude the autoregulatory effects in vivo, and the therapeutic effect was observed. Epidermal temperature changes were captured using an infrared thermal imaging camera (UTi120B, Uni-trend Technology Co.) (n=9). Subsequently, tissue samples at 2 min (immediately after first aid), 1 day, and 3 days were subjected to H&E and Masson staining for histological analysis.

[0290] As shown in the figure Figure 7 The figures show the experimental results of a rat model of second-degree burns using the hydrogel burn first aid patch (FBP) prepared in Example 10 of this invention. (a) Application of FBP on the dorsal skin of anesthetized rats, demonstrating good adherence to the burn. (b) Infrared thermography of second-degree burns before modeling (normal body temperature), after modeling (0 min), and 2 min after first aid (n=9). Blank group: burns without any first aid treatment; FBP: burns treated with FBP for 2 minutes. (c) Temperature changes within 2 minutes of burns (n=9), body temperature returned to normal after 2 minutes of first aid with the hydrogel burn first aid patch prepared in Example 10 of this invention. (d) Hematoxylin-eosin (H&E) staining of burn tissue sections 2 minutes, 1 day, and 3 days after first aid (granulation tissue: red arrow, sebaceous gland: yellow arrow, hair follicle: black arrow). (e) Masson's trichrome staining of damaged tissue (blue area: collagen, red area: muscle fiber). (f) Changes in collagen volume fraction (CVF) in damaged skin (n=3).

[0291] The above description represents the preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for preparing a hydrogel burn and scald first-aid patch, characterized in that, The preparation method comprises: (1) placing the prepared hydrogel functional layer in a mold; (2) injecting the prepared mixed sol of the hydrogel base layer into the mold in the above step (1) for solidification; (3) freeze-drying the solidified hydrogel material in step (2) and then soaking it in a solvent; (4) packaging the soaked hydrogel material with polyethylene to obtain the hydrogel burn first-aid patch; In the step (1), the preparation method of the hydrogel functional layer comprises: (11) dissolving natural polysaccharide chitosan or its derivative in a solvent to prepare an antibacterial sol; (12) dissolving the stretchable synthetic polymer polyvinyl alcohol in deionized water at high temperature to prepare a polyvinyl alcohol sol; (13) mixing the antibacterial sol in the above step (11) with the polyvinyl alcohol sol in step (12); (14) injecting the prepared sol in step (13) into a mold, freezing it in a-20 °C refrigerator for 8 h, then thawing it at room temperature for 4 h, and repeating the freezing and thawing process to obtain the hydrogel functional layer; In the step (2), the preparation method of the hydrogel base layer comprises: (21) dissolving natural polysaccharide chitosan or its derivative in a solvent to obtain an antibacterial sol; (22) dissolving a water-absorbable polymer monomer in deionized water to obtain a water-absorbable polymer monomer solution; (23) mixing the antibacterial sol in the above step (21) with the water-absorbable polymer monomer solution in step (22); (24) adding an initiator, a crosslinking agent and a catalyst to the mixed sol prepared in step (23) for chemical crosslinking; (25) injecting the prepared sol in step (24) into a mold for solidification to obtain the hydrogel base layer.

2. The method for preparing the hydrogel burn first aid patch according to claim 1, characterized in that, The natural polysaccharide chitosan or its derivative is any one of chitosan, carboxymethyl chitosan, hydrochloric chitosan or quaternary ammonium chitosan, and the antibacterial sol concentration is 2-5 wt.%; the solvent is water or a binary solvent system composed of water and an acidic / alkaline solvent; the mass ratio of the acidic / alkaline solvent to water is 0.006-0.064:1; and the acidic / alkaline solvent is any one of hydrochloric acid (HCl), acetic acid (CH3COOH), sodium hydroxide (NaOH) or potassium hydroxide (KOH).

3. The method for preparing the hydrogel burn first aid patch according to claim 1, characterized in that, In the step (12), the stretchable synthetic polymer polyvinyl alcohol is any one of PVA05-88, PVA17-88 or PVA-124, and the polyvinyl alcohol sol concentration is 5-20 wt.%; the high temperature is 60-90 °C; in the step (13), the mass ratio of the antibacterial sol to the polyvinyl alcohol sol is 0.25-2:1; and in the step (14), the cycle of freezing and thawing is not less than three times.

4. The method for preparing the hydrogel burn first aid patch according to claim 1, characterized in that, The water-absorbable polymer monomer in the step (22) is any one of acrylamide, acrylic acid, N-isopropyl acrylamide, and the concentration of the water-absorbable polymer monomer solution ranges from 5 wt.% to 30 wt.%; in the step (23), the mixing mass ratio of the antibacterial sol to the water-absorbable polymer monomer solution is 0.25-4:1; in the step (24), the initiator is any one or more of ammonium persulfate, potassium persulfate and sodium persulfate, and the concentration ranges from 0.1 wt.% to 0.5 wt.%; the crosslinking agent is N,N'-methylene bisacrylamide, and the concentration ranges from 0.05 wt.% to 0.1 wt.%; the catalyst is any one or more of tetramethyl ethylenediamine and N,N-dimethyl-1,3-propanediamine, and the concentration ranges from 0.02 vol.% to 0.2 vol.%; in the step (25), the curing condition is 25-60 °C, the gelation time is 2-24 h, or the ultraviolet light irradiation time is 10-30 min.

5. The method for preparing the hydrogel burn first aid patch according to claim 1, characterized in that, In the step (3), the freeze-drying condition is -80 °C, the vacuum degree is less than 10 Pa, and the time is 24 h.

6. The method for preparing the hydrogel burn first aid patch according to claim 1, characterized in that, In the step (3), the solvent is acidic electrolyzed water or pure water, and the soaking condition is room temperature for 24 h.

7. A hydrogel burn and scald first-aid patch, characterized in that, The hydrogel burn and scald first-aid patch is prepared by the preparation method of the hydrogel burn and scald first-aid patch according to any one of claims 1-6, and the hydrogel burn and scald first-aid patch comprises a polyethylene packaging layer, a hydrogel functional layer and a hydrogel base layer.

8. The hydrogel burn and scald first-aid patch according to claim 7, characterized in that, It is applied to the field of burn and scald wound first-aid treatment.

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