Chitosan / polyacrylic acid antibacterial self-gel composite material as well as preparation method and application thereof

Abstract

The invention relates to the technical field of composite materials, and particularly discloses a chitosan / polyacrylic acid antibacterial self-gel composite material as well as a preparation method and application thereof. The preparation method of the composite material comprises the following steps: carrying out acidolysis on chitosan to reduce the crystallinity, reacting with a cross-linking agent genipin to generate a covalent cross-linked network structure, compounding with modified polyacrylic acid under an electrostatic adsorption effect to generate polyelectrolyte, dialyzing, freeze-drying, grinding into powder, and sieving to obtain the composite material. The material can rapidly absorb blood at a hemorrhagic spot and form gel in situ through movement of a macromolecular chain to be adhered to the hemorrhagic spot, the hemostatic effect can be achieved within 180 s, the formed gel can resist bursting pressure larger than 120 mm Hg, bleeding is effectively stopped, and meanwhile a stable physical barrier is formed to protect a wound part; the problem that traditional hemostatic materials are poor in adhesiveness and need external force to press wounds to assist in hemostasis is solved. The preparation method provided by the invention has the advantages of low cost of required raw materials, simple process operation and considerable application prospect in medical hemostatic products.

Description

Technical Field

[0001] The invention belongs to the technical field of composite materials, and in particular relates to a chitosan / polyacrylic acid antibacterial self-gel composite material and a preparation method and application thereof. Background Art

[0002] So far, researchers have developed a large number of hemostatic materials, such as sponges, bandages, hydrogels and hemostatic powders. Although sponge and bandage hemostatic materials can absorb a large amount of blood and concentrate hemostatic factors, they are not suitable for non-compressible hemostasis because they need external pressure to achieve hemostatic effect, and their use scenarios are limited; hydrogel hemostatic materials use chemical / physical cross-linking to form a three-dimensional network structure, which can keep the wound moist and promote healing while sealing the wound, but its texture is difficult to preserve, and the cross-linking usually takes a long time, making it difficult to effectively achieve hemostatic effect; traditional hemostatic powder has a high specific surface area, quickly absorbs water in the blood, concentrates hemostatic factors and platelets, and has a wide range of applications, but the powder particles lack interaction and it is difficult to form a stable physical barrier to deal with heavy bleeding. Therefore, the ideal hemostatic material can not only stop bleeding quickly and effectively, but also protect the wound from bacterial and viral infection and provide a good healing environment for the wound; at the same time, it can resist blood flow pressure, form a stable physical hemostatic barrier, and prevent uncontrolled bleeding. Self-coagulating powder can quickly absorb water from the blood and form a stable hydrogel barrier in situ on the surface of the bleeding wound through chemical or physical interactions, such as electrostatic adsorption, hydrogen bonding or covalent bonding, which can coagulate platelets and hemostatic factors while sealing the bleeding point. Therefore, self-coagulating powder has great application potential in rapid hemostasis. How to develop a fast and effective antibacterial hemostatic material is of great significance to reducing bleeding and saving lives. Summary of the invention

[0003] The purpose of the present invention is to provide a chitosan / polyacrylic acid antibacterial self-gel composite material and a preparation method and application thereof in view of the deficiencies in the prior art. The material can quickly absorb blood at the bleeding point and form a gel in situ through the movement of the polymer chain to adhere to the bleeding point, and can achieve a hemostatic effect within 180 seconds. After the gel is formed, it can resist a bursting pressure greater than 120 mm Hg, effectively stop bleeding, and form a stable physical barrier to protect the wound site, thereby solving the problem that the traditional hemostatic material has poor adhesion and needs to rely on external force to compress the wound to assist in hemostasis.

[0004] To achieve the above object, the present invention adopts the following technical solution:

[0005] The first object of the present invention is to provide a method for preparing a chitosan / polyacrylic acid antibacterial self-gel composite material, comprising the following steps:

[0006] S1, decomposing chitosan with hydrochloric acid, and obtaining acid-decomposed chitosan powder after drying, wherein the deacetylation degree of the chitosan is 85-98%;

[0007] S2, dissolving the acid-decomposed chitosan powder in water to obtain a chitosan aqueous solution, then adding the genipin solution to the chitosan aqueous solution, stirring the reaction, and obtaining a cross-linked chitosan solution;

[0008] S3, preparing a modified polyacrylic acid solution, adding tannic acid to the polyacrylic acid solution, stirring and reacting, to obtain a modified polyacrylic acid solution;

[0009] S4, compounding the cross-linked chitosan solution and the modified polyacrylic acid solution in the same volume ratio, rapidly stirring to form a polyelectrolyte, and then adding a large amount of deionized water for precipitation to obtain a polyelectrolyte precipitate;

[0010] S5. The polyelectrolyte precipitate is dialyzed with deionized water, the dialyzed polyelectrolyte is freeze-dried, then ground into powder, and sieved to obtain an antibacterial self-coagulating hemostatic powder material.

[0011] Furthermore, in step S1, the mass concentration of the hydrochloric acid is 10-40%, the acid hydrolysis temperature is 40-80° C., and the acid hydrolysis time is 1-24 h.

[0012] Furthermore, in step S2, the mass ratio of the acid-decomposed chitosan powder to the polyacrylic acid is 1:0 to 1:4.

[0013] Furthermore, in step S2, the genipin solution is 0.1% to 0.5% of the mass of the chitosan.

[0014] Furthermore, in step S3, the mass concentration of the tannic acid is 0.5wt% to 2.5%.

[0015] The second object of the present invention is to provide a chitosan / polyacrylic acid antibacterial self-gel composite material prepared by the above-mentioned preparation method.

[0016] The third object of the present invention is to provide an application of the chitosan / polyacrylic acid antibacterial self-gel composite material in the preparation of hemostatic products.

[0017] Furthermore, the hemostatic product is a hemostatic dressing or a hemostatic device.

[0018] Furthermore, the hemostatic dressing includes the chitosan / polyacrylic acid antibacterial self-gel composite material powder. When used, the chitosan / polyacrylic acid antibacterial self-gel composite material powder is applied to the wound part and absorbs blood to form a gel layer in situ when it encounters blood.

[0019] Furthermore, the hemostatic device is a hemostatic device for inserting into the body of a human or lower mammal, and comprises a composition of the chitosan / polyacrylic acid antibacterial self-gel composite material and other conventional hemostatic products.

[0020] Compared with the prior art, the technical solution provided by the present invention has the following beneficial effects:

[0021] (1) The present invention provides a chitosan / polyacrylic acid antibacterial self-gel composite material, wherein chitosan is acid-hydrolyzed to reduce crystallinity, reacted with a cross-linking agent genipin to form a covalent cross-linked network structure, and then compounded with modified polyacrylic acid to form a polyelectrolyte by electrostatic adsorption, dialyzed and freeze-dried, then ground into powder, and sieved to obtain a cross-linked chitosan / polyacrylic acid self-gel antibacterial hemostatic composite powder material. The cross-linking of chitosan forms a three-dimensional covalent network structure, and the covalent bonds formed between chitosan and the cross-linking agent replace part of the electrostatic adsorption between chitosan and polyacrylic acid to improve the mechanical properties of the hemostatic powder gel state. At the same time, the three-dimensional covalent network structure also increases the complexity of the interpenetrating network interwoven multi-pore structure of the hemostatic powder in the gel state, which is more conducive to the deposition of platelets and red blood cells. By using modified polyacrylic acid, a large number of carboxyl groups, hydroxyl groups or succinic acid succinimide ester bonds in the modifier can react with amino groups and carboxyl groups on skin tissue, so that the powder adheres firmly to the surface of the skin tissue when forming a gel in situ, forming a physical barrier. The polyacrylic acid has a large number of hydrophilic carboxyl groups, which can quickly absorb water in the blood, concentrate blood cells and hemostatic factors, and at the same time, the negatively charged carboxyl groups repel negatively charged red blood cells, further accelerating the aggregation speed of chitosan on red blood cells.

[0022] (2) The chitosan / polyacrylic acid self-gel antibacterial hemostatic composite powder material provided by the present invention can quickly absorb blood at the bleeding point and form a gel in situ through the movement of the polymer chain to adhere to the bleeding point. It can achieve a hemostatic effect within 180 seconds and can resist a burst pressure greater than 120 mm Hg after forming a gel, effectively stopping bleeding while forming a stable physical barrier to protect the wound site. Through the antibacterial performance test, the powder material has a strong antibacterial effect on both fungi and bacteria, and the antibacterial rate of Escherichia coli and Staphylococcus aureus can reach more than 99.00%, which has a good antibacterial effect. Through the hemolysis rate and cytotoxicity test of the powder, it will not cause hemolysis to red blood cells (hemolysis rate <5%); it has no cytotoxicity to mouse fibroblasts (cell viability>85%), indicating that the powder material has good biocompatibility. The present invention solves the problem that traditional hemostatic materials have poor adhesion and need to use external force to compress the wound to assist hemostasis. It is a rapid hemostatic material with good adhesion strength, antibacterial performance and biocompatibility.

[0023] (3) The preparation method provided by the present invention requires low raw material costs, is simple to operate, and has promising application prospects in medical hemostatic products. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 A schematic diagram of a scanning electron microscope image of a chitosan / polyacrylic acid antibacterial self-gel composite material in powder form provided by the present invention;

[0025] Figure 2 A schematic diagram of a scanning electron microscope image of a chitosan / polyacrylic acid antibacterial self-gel composite material in a gel state provided by the present invention;

[0026] Figure 3 Optical photograph of the chitosan / polyacrylic acid antibacterial self-gel composite material provided by the present invention acting on the wet tissue surface of pig skin;

[0027] Figure 4 The optical photos are of the chitosan / polyacrylic acid antibacterial self-gel composite material provided by the present invention adhered to pig skin under various effects. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical scheme and advantages of the present invention clearer, the specific embodiments of the present invention are further described in detail below in conjunction with specific examples and drawings. If no specific technology or conditions are specified in the examples, the technology or conditions described in the literature in this field or the product instructions are used. If the manufacturer of the reagents or instruments is not specified, they are all conventional products that can be obtained commercially.

[0029] Example 1

[0030] This embodiment provides a method for preparing a chitosan / polyacrylic acid antibacterial self-gel composite material.

[0031] The specific steps are as follows:

[0032] Step 1: 20 g of chitosan with a deacetylation degree of 96.2% was dispersed in 120 mL of 36 wt.% hydrochloric acid for acid hydrolysis, and after stirring for 2.5 h, anhydrous ethanol was added to stop the reaction, and the chitosan was repeatedly washed until neutral, and vacuum dried to obtain acid-decomposed chitosan;

[0033] Step 2: dissolving acid-decomposed chitosan powder in deionized water to prepare a 15wt.% chitosan aqueous solution; adding 0.40% genipin aqueous solution of chitosan mass to the chitosan aqueous solution, stirring at 400 rpm for 14 h to obtain a cross-linked chitosan solution;

[0034] Step 3: preparing polyacrylic acid into a 15 wt.% polyacrylic acid aqueous solution, adding 2.5 wt.% tannic acid thereto, stirring at a speed of 400 rpm for 30 min, to obtain a modified polyacrylic acid solution;

[0035] Step 4: Compound the cross-linked chitosan solution and the modified polyacrylic acid solution in the same volume ratio, rapidly stir at 1000 rpm for 15 min to form a polyelectrolyte, add a large amount of deionized water, and precipitate the polyelectrolyte;

[0036] Step 5: The polyelectrolyte precipitate is dialyzed with deionized water for 2 hours, freeze-dried for 48 hours, and then ground into powder. The particle size is sieved using a 100-mesh sieve to obtain an antibacterial self-coagulating hemostatic powder material.

[0037] Example 2

[0038] This embodiment provides a method for preparing a chitosan / polyacrylic acid antibacterial self-gel composite material.

[0039] The specific steps are as follows:

[0040] Step 1: 20 g of chitosan with a deacetylation degree of 96.2% was dispersed in 120 mL of 36 wt.% hydrochloric acid for acid hydrolysis, and after stirring for 2.5 h, anhydrous ethanol was added to stop the reaction, and the chitosan was repeatedly washed until neutral, and vacuum dried to obtain acid-decomposed chitosan;

[0041] Step 2: dissolving acid-decomposed chitosan powder in deionized water to prepare a 15wt.% chitosan aqueous solution; adding 0.20% genipin aqueous solution of chitosan mass to the chitosan aqueous solution, stirring at 400rpm for 14h to obtain a cross-linked chitosan solution;

[0042] Step 3: preparing polyacrylic acid into a 15 wt.% polyacrylic acid aqueous solution; adding 2.5 wt.% tannic acid thereto, stirring at a speed of 400 rpm for 30 min, to obtain a modified polyacrylic acid solution;

[0043] Step 4: Compound the cross-linked chitosan solution and the modified polyacrylic acid solution in the same volume ratio, rapidly stir at 1000 rpm for 15 min to form a polyelectrolyte, add a large amount of deionized water, and precipitate the polyelectrolyte;

[0044] Step 5: The polyelectrolyte precipitate is dialyzed with deionized water for 2 hours, freeze-dried for 48 hours, and then ground into powder. The particle size is sieved using a 100-mesh sieve to obtain an antibacterial self-coagulating hemostatic powder material.

[0045] Example 3

[0046] This embodiment provides a method for preparing a chitosan / polyacrylic acid antibacterial self-gel composite material.

[0047] The specific steps are as follows:

[0048] Step 1: 20 g of chitosan with a deacetylation degree of 96.2% was dispersed in 120 mL of 36 wt.% hydrochloric acid for acid hydrolysis, and after stirring for 2.5 h, anhydrous ethanol was added to stop the reaction, and the chitosan was repeatedly washed until neutral, and vacuum dried to obtain acid-decomposed chitosan;

[0049] Step 2: dissolving acid-decomposed chitosan powder in deionized water to prepare a 15wt.% chitosan aqueous solution; adding 0.40% genipin aqueous solution of chitosan mass to the chitosan aqueous solution, stirring at 400 rpm for 14 h to obtain a cross-linked chitosan solution;

[0050] Step 3: preparing polyacrylic acid into a 15 wt.% polyacrylic acid aqueous solution; adding 1.5 wt.% tannic acid thereto, stirring at a speed of 400 rpm for 30 min, to obtain a modified polyacrylic acid solution;

[0051] Step 4: Compound the cross-linked chitosan solution and the modified polyacrylic acid solution in the same volume ratio, rapidly stir at 1000 rpm for 15 min to form a polyelectrolyte, add a large amount of deionized water, and precipitate the polyelectrolyte;

[0052] Step 5: The polyelectrolyte precipitate is dialyzed with deionized water for 2 hours, freeze-dried for 48 hours, and then ground into powder. The particle size is sieved using a 100-mesh sieve to obtain an antibacterial self-coagulating hemostatic powder material.

[0053] Example 4

[0054] This embodiment provides a method for preparing a chitosan / polyacrylic acid antibacterial self-gel composite material.

[0055] The specific steps are as follows:

[0056] Step 1: 20 g of chitosan with a deacetylation degree of 96.2% was dispersed in 120 mL of 36 wt.% hydrochloric acid for acid hydrolysis, and after stirring for 2.5 h, anhydrous ethanol was added to stop the reaction, and the chitosan was repeatedly washed until neutral, and vacuum dried to obtain acid-decomposed chitosan;

[0057] Step 2: dissolving acid-decomposed chitosan powder in deionized water to prepare a 15wt.% chitosan aqueous solution; adding 0.10% genipin aqueous solution of the mass of chitosan to the chitosan aqueous solution, stirring at 400rpm for 14h to obtain a cross-linked chitosan solution;

[0058] Step 3: preparing polyacrylic acid into a 15 wt.% polyacrylic acid aqueous solution; adding 0.5 wt.% tannic acid thereto, stirring at a speed of 400 rpm for 30 min, to obtain a modified polyacrylic acid solution;

[0059] Step 4: Compound the cross-linked chitosan solution and the modified polyacrylic acid solution in the same volume ratio, rapidly stir at 1000 rpm for 15 min to form a polyelectrolyte, add a large amount of deionized water, and precipitate the polyelectrolyte;

[0060] Step 5: The polyelectrolyte precipitate is dialyzed with deionized water for 2 hours, freeze-dried for 48 hours, and then ground into powder. The particle size is sieved using a 100-mesh sieve to obtain an antibacterial self-coagulating hemostatic powder material.

[0061] Example 5

[0062] This embodiment provides a method for preparing a chitosan / polyacrylic acid antibacterial self-gel composite material.

[0063] The specific steps are as follows:

[0064] Step 1: 20 g of chitosan with a deacetylation degree of 96.2% was dispersed in 120 mL of 36 wt.% hydrochloric acid for acid hydrolysis, and after stirring for 2.5 h, anhydrous ethanol was added to stop the reaction, and the chitosan was repeatedly washed until neutral, and vacuum dried to obtain acid-decomposed chitosan;

[0065] Step 2: dissolving acid-decomposed chitosan powder in deionized water to prepare a 15wt.% chitosan aqueous solution; adding 0.10% genipin aqueous solution of the mass of chitosan to the chitosan aqueous solution, stirring at 400rpm for 14h to obtain a cross-linked chitosan solution;

[0066] Step 3: preparing polyacrylic acid into a 15 wt.% polyacrylic acid aqueous solution; adding 0.5 wt.% tannic acid thereto, stirring at a speed of 400 rpm for 30 min, to obtain a modified polyacrylic acid solution;

[0067] Step 4: Compound the cross-linked chitosan solution and the modified polyacrylic acid solution in the same volume ratio, rapidly stir at 1000 rpm for 15 min to form a polyelectrolyte, add a large amount of deionized water, and precipitate the polyelectrolyte;

[0068] Step 5: The polyelectrolyte precipitate is dialyzed with deionized water for 2 hours, freeze-dried for 48 hours, and then ground into powder. The particle size is sieved using a 50-mesh sieve to obtain an antibacterial self-coagulating hemostatic powder material.

[0069] Comparative Example 1

[0070] The method is basically the same as Example 1, except that tannic acid is not added as a modifier, and the other steps are the same as Example 1 to obtain a cross-linked chitosan / polyacrylic acid self-gel composite material.

[0071] Comparative Example 2

[0072] The method is basically the same as Example 1, except that genipin is not added as a cross-linking agent, and tannic acid is not added as a modifier. The other steps are the same as Example 1 to obtain a chitosan / polyacrylic acid self-gel composite material.

[0073] Comparative Example 3

[0074] The method is basically the same as Example 1, except that genipin is not added as a cross-linking agent, and the chitosan aqueous solution is directly freeze-dried, ground and sieved to obtain a chitosan powder material.

[0075] In order to better illustrate the performance characteristics of the chitosan / polyacrylic acid antibacterial self-gel composite material provided by the present invention, the inventors conducted the following research:

[0076] 1. Material mechanical properties test:

[0077] The adhesion strength, interface toughness and bursting pressure performance tests were performed on Examples 1 to 5 and Comparative Examples 1 to 3. The adhesion strength and interface toughness were tested using the fresh pigskin wet tissue tensile method, and the bursting pressure was tested using a three-way device in which a differential pressure gauge and an injection pump were connected to the broken pigskin. The test results are shown in Table 1 below.

[0078] Table 1. Material mechanical properties test results.

[0079]

[0080] As can be seen from Table 1 above, the mechanical properties of the antibacterial self-gelling powder with rapid hemostasis prepared in Examples 1 to 5 are better than those in Comparative Examples 2 to 3. As can be seen from Examples 1 to 5 and Comparative Example 1, tannic acid improves the mechanical properties of the gel matrix, and a large number of hydrogen bonds are formed between tannic acid and the gel matrix and skin tissue, thereby improving the adhesion. As can be seen from Examples 1 to 5 and Comparative Example 2, the addition of genipin forms a three-dimensional covalent multi-level interpenetrating network structure, which improves the stability of the material in the gel state. As can be seen from Examples 1 to 5 and Comparative Example 3, polyacrylic acid can greatly improve the mechanical properties of the natural polymer chitosan, so that the powder has adhesion in the gel state.

[0081] 2. Material antibacterial performance test:

[0082] Examples 1 to 5 and comparative examples 1 to 3 were selected for antibacterial performance testing. The antibacterial performance was tested using a plate count method, and the test results are shown in Table 2 below.

[0083] Table 2. Material antibacterial performance test results.

[0084]

[0085]

[0086] As can be seen from Table 2 above, the antibacterial self-gelling powder with rapid hemostasis prepared in Examples 1 to 5 has better antibacterial properties than Comparative Examples 2 to 3. As can be seen from Examples 1 to 5 and Comparative Example 1, tannic acid itself has excellent antibacterial properties, and its performance against both Gram-negative and Gram-positive bacteria of the powder material is improved. As can be seen from Examples 1 to 5 and Comparative Example 2, the addition of genipin cross-links with chitosan to form a Schiff base structure, and the Schiff base has certain antibacterial properties. As can be seen from Examples 1 to 5 and Comparative Example 3, chitosan is resistant to bacteria in a dose-dependent manner.

[0087] 3. Material biocompatibility test and in vitro coagulation index test

[0088] Examples 1 to 5 and comparative examples 1 to 3 were selected for cytotoxicity, hemolytic performance and in vitro coagulation index detection. The cytotoxicity was tested by the CCK-8 method on L929 cells, the hemolytic performance was tested by the red blood cell and sample co-culture method, and the in vitro coagulation index test was tested on the coagulation index of the sample at 180s. The lower the coagulation index, the better the coagulation effect. The test results are shown in Table 3 below.

[0089] Table 3. Material biocompatibility and in vitro coagulation index results.

[0090] Cell survival rate (%) Hemolytic (%) Coagulation index (%) Example 1 88.69 2.83 9.06 Example 2 88.79 1.69 10.69 Example 3 88.69 2.44 10.70 Example 4 93.91 1.72 16.83 Example 5 94.02 1.55 17.89 Comparative Example 1 88.69 2.64 10.75 Comparative Example 2 101.57 1.10 20.75 Comparative Example 3 103.19 2.11 32.13

[0091] As can be seen from Table 3 above, the biocompatibility and coagulation index of a rapid hemostatic antibacterial self-gel powder prepared in Examples 1 to 5 are better than those in Comparative Examples 2 to 3. As can be seen from Examples 1 to 5 and Comparative Example 1, tannic acid has excellent coagulation properties, and it reacts with hemoglobin to form a precipitate, which accelerates the speed of blood thrombosis and reduces the coagulation index; at the same time, tannic acid also has good biocompatibility. As can be seen from Examples 1 to 5 and Comparative Example 2, the addition of genipin forms a three-dimensional covalent multi-level interpenetrating network structure, which helps the deposition of blood cells and platelets and accelerates the formation of thrombi; at the same time, genipin has excellent biocompatibility as a natural plant extract. As can be seen from Examples 1 to 5 and Comparative Example 3, the positively charged amino groups of chitosan adsorb negatively charged red blood cells, accelerating the aggregation of red blood cells.

[0092] 4. In vivo hemostatic performance test

[0093] Example 1 and Comparative Example 3 were selected to test the in vivo hemostatic performance in rats. The in vivo hemostatic performance was tested on the bleeding volume and hemostasis time using a rat liver injury model. The test results are shown in Table 4 below.

[0094] Table 4. In vivo hemostatic performance test results.

[0095] Amount of bleeding (mg) Hemostasis time (s) Example 1 215 165 Comparative Example 3 786 292

[0096] 5. In vivo degradation test

[0097] The chitosan / polyacrylic acid antibacterial self-gel composite material provided by the present invention is degradable under conditions related to wounds in or on the human or animal body. In one example, the gel film formed by the material can be safely degraded in vivo within a reasonable period of time (e.g., about 30 days), so that the entire hemostatic material film can be left in place after surgical use or treatment.

[0098] In the absence of conflict, the above embodiments and features in the embodiments may be combined with each other.

[0099] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for preparing a chitosan / polyacrylic acid antibacterial self-gel composite material, characterized in that: The following steps are involved: S1, decomposing chitosan with hydrochloric acid, and obtaining acid-decomposed chitosan powder after drying, wherein the deacetylation degree of the chitosan is 85-98%; S2, dissolving the acid-decomposed chitosan powder in water to obtain a chitosan aqueous solution, then adding the genipin solution to the chitosan aqueous solution, stirring the reaction, and obtaining a cross-linked chitosan solution; S3, preparing a modified polyacrylic acid solution, adding tannic acid to the polyacrylic acid solution, stirring and reacting, to obtain a modified polyacrylic acid solution; S4, compounding the cross-linked chitosan solution and the modified polyacrylic acid solution in the same volume ratio, rapidly stirring to form a polyelectrolyte, and then adding a large amount of deionized water for precipitation to obtain a polyelectrolyte precipitate; S5. The polyelectrolyte precipitate is dialyzed with deionized water, the dialyzed polyelectrolyte is freeze-dried, then ground into powder, and sieved to obtain an antibacterial self-coagulating hemostatic powder material.

2. The preparation method according to claim 1, characterized in that In step S1, the mass concentration of the hydrochloric acid is 10-40%, the acid hydrolysis temperature is 40-80° C., and the acid hydrolysis time is 1-24 h.

3. The preparation method according to claim 1, characterized in that: In step S2, the mass ratio of the acid-decomposed chitosan powder to the polyacrylic acid is 1:0 to 1:

4.

4. The preparation method according to claim 1, characterized in that: In step S2, the genipin solution is 0.1% to 0.5% of the mass of the chitosan.

5. The preparation method according to claim 1, characterized in that: In step S3, the mass concentration of the tannic acid is 0.5wt% to 2.5%.

6. A chitosan / polyacrylic acid antibacterial self-gel composite material, characterized in that: The method is prepared according to any one of claims 1 to 5.

7. Use of the chitosan / polyacrylic acid antibacterial self-gel composite material as claimed in claim 6 in the preparation of hemostatic products.

8. The use according to claim 7, characterized in that The hemostatic product is a hemostatic dressing or a hemostatic device.

9. The use according to claim 8, characterized in that The hemostatic dressing comprises the chitosan / polyacrylic acid antibacterial self-gel composite material powder as claimed in claim 6. When used, the chitosan / polyacrylic acid antibacterial self-gel composite material powder is applied to the wound part and absorbs blood to form a gel layer in situ when it encounters blood.

10. The use according to claim 8, characterized in that The hemostatic device is a hemostatic device for inserting into the body of a human or lower mammal, and comprises a composition of the chitosan / polyacrylic acid antibacterial self-gel composite material according to claim 6 and other conventional hemostatic products.

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