Rapid self-gel hemostatic powder as well as preparation method and application thereof

Abstract

The invention discloses rapid self-gel hemostatic powder as well as a preparation method and application thereof, and belongs to the technical field of biomedical materials. The rapid self-gel hemostatic powder provided by the invention is prepared by reacting modified polyacrylic acid with polyethyleneimine; the modified polyacrylic acid is prepared by grafting 2-methylallylamine onto polyacrylic acid through a condensing agent to obtain double-bond modified polyacrylic acid; and the condensing agent is dicyclohexylcarbodiimide. The hemostatic powder is obtained by compounding and hybridizing negatively charged double-bond modified polyacrylic acid and positively charged polyethyleneimine. When the hemostatic powder is applied to a wound, the hemostatic powder can quickly absorb blood and moisture of the wound to form gel through electrostatic interaction, so that the hemostatic powder is quickly self-gelated to form an initial physical barrier, and preliminary hemostasis is realized; further covalent crosslinking is formed through photo-initiation, and the bi-crosslinking hydrogel is formed, so that the mechanical property of a gel body is enhanced, and the hydrogel has excellent tissue adhesiveness and hemostasis performance.

Description

Technical Field

[0001] The present application belongs to the technical field of biomedical materials, and in particular relates to a rapid self-gelling hemostatic powder and a preparation method and application thereof. Background Art

[0002] Hemostatic powders can be widely used in hemostasis of diffuse bleeding, incompressible soft tissues and soft organs due to their shape adaptability. At present, the design strategies of hemostatic powders are mainly divided into two categories: promoting physiological coagulation and building physical barriers. The strategy of promoting physiological coagulation is to use powder materials to activate the coagulation system, or to use powders to enrich blood cells to initiate and accelerate the formation of blood clots. However, blood clots are easily washed away by the blood flow during the formation process and are not suitable for hemostasis in people with coagulation disorders. The strategy of building a physical barrier is to use the powder to absorb water and self-gel to form a physical barrier to achieve hemostasis. However, the mechanical strength and adhesion properties of the barrier formed by the current powder under high-pressure bleeding conditions are insufficient, which limits its clinical application in heavy bleeding or persistent bleeding. Therefore, there is an urgent need to design a comprehensive hemostatic powder that has both efficient coagulation activation ability and strong mechanical barrier properties.

[0003] For example, the prior art application publication number CN 119733081 A discloses a polyethyleneimine / polyacrylic acid-based hydrogel powder for wound repair, which is prepared by reacting a polyacrylic acid solution modified with N-hydroxysuccinimide with a polyethyleneimine aqueous solution.

[0004] However, the existing hydrogel powders have the following problems: First, the current powders with hemostatic functions (promoting physiological coagulation or building a physical barrier) have insufficient mechanical strength and adhesion of the formed single network structure under high bleeding pressure conditions, which limits their clinical application; second, in the current covalently cross-linked powder hemostatic materials, covalent cross-linking will affect the penetration and entanglement of molecular chains between powder particles and between powder and tissue, resulting in insufficient mechanical and adhesion properties in actual applications, making it difficult to form a sustained and stable hemostatic barrier on the wound surface, ultimately leading to a decrease in hemostatic efficiency or even failure. Summary of the Invention

[0005] The present application discloses a rapid self-gelling hemostatic powder and its preparation method and application, aiming to solve the technical problems of existing hemostatic powders, such as poor tissue adhesion strength, insufficient mechanical properties of the hemostatic barrier formed, and poor hemostatic effect.

[0006] In order to achieve the above objectives, the technical solution of this application is:

[0007] The first aspect of the present application provides a fast self-gelling hemostatic powder, which is prepared by reacting modified polyacrylic acid with polyethyleneimine;

[0008] The modified polyacrylic acid is obtained by grafting 2-methylallylamine onto the polyacrylic acid through a condensation agent;

[0009] The condensing agent is dicyclohexylcarbodiimide.

[0010] In combination with the first aspect, preferably, the molecular weight of the polyacrylic acid is 2-100 kDa;

[0011] The degree of polymerization of the polyethyleneimine is 70 kDa.

[0012] In combination with the first aspect, preferably, the molar ratio of the modified polyacrylic acid to polyethyleneimine is (3:7)-(5:5).

[0013] In combination with the first aspect, preferably, the molar ratio of the 2-methylallylamine to the carboxyl group in the polyacrylic acid is 11:(50-200).

[0014] In combination with the first aspect, preferably, the molar ratio of dicyclohexylcarbodiimide to 2-methylallylamine is 10:11.

[0015] The second aspect of the present application provides a method for preparing the rapid self-gelling hemostatic powder described in the first aspect, the preparation method comprising:

[0016] Dissolving polyacrylic acid, 2-methylallylamine and dicyclohexylcarbodiimide in N-methylpyrrolidone for reaction, separating and collecting the product to obtain polyacrylic acid grafted with double bonds;

[0017] The polyacrylic acid grafted with double bonds is reacted with polyethyleneimine, and then freeze-dried and ground to obtain the rapid self-gel hemostatic powder.

[0018] In combination with the second aspect, preferably, the temperature when the polyacrylic acid, 2-methylallylamine and dicyclohexylcarbodiimide are dissolved in N-methylpyrrolidone for the reaction is 40-80° C. and the reaction time is 12-48 hours.

[0019] In combination with the second aspect, preferably, the temperature for reacting the polyacrylic acid grafted with double bonds with polyethyleneimine is 25-37° C. and the time is 0.25-24 h.

[0020] The third aspect of the present application provides the use of the fast self-gelling hemostatic powder prepared by the preparation method described in the second aspect in the preparation of medical hemostatic materials.

[0021] In combination with the second aspect, preferably, the rapid self-gelling hemostatic powder is used to absorb blood at the wound site, rapidly self-gels at the wound through electrostatic interaction to form an initial physical barrier, and further forms covalent cross-links under the action of phenyl (2,4,6-trimethylbenzoyl) lithium phosphate and 405nm wavelength blue light, thereby achieving rapid hemostasis through a double cross-linked hydrogel barrier.

[0022] Compared with the prior art, the advantages or beneficial effects of the embodiments of the present application include at least:

[0023] The fast self-gelling hemostatic powder provided by the present application is prepared by grafting 2-methylallylamine onto polyacrylic acid and then reacting it with polyethyleneimine. On the one hand, after the negatively charged double bond-modified polyacrylic acid is hybridized with the positively charged polyethyleneimine, covalent cross-linking is not easily caused before use. Only when it is used on the wound site, it can quickly absorb blood and moisture in the wound site to form a gel through electrostatic action, thereby quickly self-gelling to form an initial physical barrier and achieve preliminary hemostasis; further covalent cross-linking is then formed through photoinitiation to form a double-cross-linked hydrogel, thereby enhancing the mechanical properties of the gel body and having excellent tissue adhesion and hemostatic properties; secondly, the fast self-gelling hemostatic powder can stably and effectively exert its hemostatic function in a complex physiological environment, has no special requirements for the location and shape of the wound, is simple to operate, and has good biosafety. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] To more clearly illustrate the technical solutions of the embodiments of this application, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some of the embodiments described in this application. For those skilled in the art, other drawings can be derived from these drawings without inventive effort.

[0025] Figure 1 This is the hydrogen nuclear magnetic resonance spectrum of the modified polyacrylic acid prepared in the examples of the present application;

[0026] Figure 2 This is a scanning electron micrograph of the A1-fast self-gel hemostatic powder prepared in an example of the present application;

[0027] Figure 3 The lap shear strength of A3-fast self-gelling hemostatic powder, A4-fast self-gelling hemostatic powder, and A5-fast self-gelling hemostatic powder prepared in the examples of the present application on glass;

[0028] Figure 4 This is a graph showing the lap shear strength of A1-fast self-gelling hemostatic powder and B1 hemostatic powder prepared in the examples of the present application on tissue;

[0029] Figure 5 The lap shear strength of A1-fast self-gelling hemostatic powder, A2-fast self-gelling hemostatic powder, A3-fast self-gelling hemostatic powder, B2-hemostatic powder, and B3-hemostatic powder prepared in the examples of the present application on glass;

[0030] Figure 6Rheological properties of dPAA-db / PEI hydrogel and ePAA-db / PEI hydrogel formed by A1-fast self-gelling hemostatic powder prepared in the examples of this application;

[0031] Figure 7 Figure 3 is a stress-strain curve of the tensile test of dPAA-db / PEI hydrogel and ePAA-db / PEI hydrogel formed by the A1-fast self-gelling hemostatic powder prepared in the examples of the present application;

[0032] Figure 8 Graph showing the Young's modulus and tensile strength of dPAA-db / PEI hydrogel and ePAA-db / PEI hydrogel formed by the A1-fast self-gelling hemostatic powder prepared in the examples of the present application;

[0033] Figure 9 Graphs showing stress-strain curves of compression tests of dPAA-db / PEI hydrogels and ePAA-db / PEI hydrogels formed from the A1-fast self-gelling hemostatic powder prepared in Examples of the present application;

[0034] Figure 10 Graphs showing the compression modulus and compression stress at 80% strain of dPAA-db / PEI hydrogel and ePAA-db / PEI hydrogel formed by the A1-fast self-gelling hemostatic powder prepared in an example of the present application;

[0035] Figure 11 Graph showing the tissue adhesion performance of dPAA-db / PEI hydrogel and ePAA-db / PEI hydrogel formed by A1-fast self-gelling hemostatic powder prepared in Examples of the present application;

[0036] Figure 12 Live-dead fluorescence staining images of L929 cells cultured in dPAA-db / PEI hydrogel extract for 24, 48, and 72 hours in the example of this application;

[0037] Figure 13 These are graphs showing the hemostatic effects and statistical results of blood loss of the dPAA-db / PEI hydrogel and ePAA-db / PEI hydrogel prepared in the examples of this application in a rat liver incision model. DETAILED DESCRIPTION

[0038] The following will be combined with the accompanying drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the described embodiments are part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0039] In the following description of this embodiment, the term "and / or" is used to describe the association relationship between associated objects, indicating that three possible relationships exist. For example, A and / or B can represent: A exists alone, B exists alone, and both A and B exist. A and B can be singular or plural. The character " / " generally indicates that the associated objects are in an "or" relationship.

[0040] In the following description of this embodiment, the term "at least one" refers to one or more, and "plurality" refers to two or more. "At least one of the following" or similar expressions refers to any combination of these items, including any combination of single items or plural items. For example, "at least one of a, b, or c", or "at least one of a, b, and c" can all represent: a, b, c, ab (i.e., a and b), ac, bc, or abc, where a, b, and c can be single or multiple.

[0041] Those skilled in the art should understand that in the following description of the embodiments of the present application, the order of serial numbers does not mean the order of execution, some or all of the steps can be executed in parallel or sequentially, and the execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0042] The terms used in the embodiments of the present application are only for the purpose of describing specific embodiments and are not intended to limit the present application. The singular forms "a", "an" and "the" used in the embodiments of the present application and the appended claims are also intended to include plural forms unless the context clearly indicates otherwise.

[0043] It should be noted that all raw materials and reagents in the examples of the present application were purchased on the market or prepared according to conventional methods well known to those skilled in the art.

[0044] In a first aspect, the embodiments of the present application provide a fast self-gelling hemostatic powder, which is prepared by reacting modified polyacrylic acid with polyethyleneimine;

[0045] The modified polyacrylic acid is obtained by grafting 2-methylallylamine onto the polyacrylic acid through a condensation agent;

[0046] The condensing agent is dicyclohexylcarbodiimide (DCC).

[0047] Among them, on the one hand, after the negatively charged double bond modified polyacrylic acid is hybridized with the positively charged polyethyleneimine, it is not easy to undergo covalent cross-linking in the powder state. Only when it is used on the wound site, it can quickly absorb the blood and moisture in the wound site to form a gel through electrostatic action, thereby quickly self-gelling to form an initial physical barrier and achieve preliminary hemostasis; then further covalent cross-linking is formed through photoinitiation to form a double-cross-linked hydrogel, thereby enhancing the mechanical properties of the gel body, and having excellent tissue adhesion and hemostatic properties; on the other hand, this rapid self-gelling hemostatic powder has no special requirements for the location and shape of the wound, is simple to operate, and has good biosafety.

[0048] It should be noted that in the prior art, succinimide is grafted onto polyacrylic acid, which is then combined with polyethyleneimine to form a gel, which is then freeze-dried and ground into a powder. However, the covalent crosslinking between the succinimide groups and polyethyleneimine can hinder the penetration and entanglement of molecular chains between powder particles or between the powder and tissue.

[0049] It should be noted that the hemostatic powder prepared in this application utilizes both rapid self-gelation of hydration and enhanced light-triggered covalent cross-linking. The powder is obtained by hybridizing negatively charged grafted double-bond polyacrylic acid (PAA-db) with positively charged polyethyleneimine (PEI) and freeze-drying and grinding. It can quickly absorb blood and water from the wound site to form a gel through electrostatic action, thereby rapidly self-gelating to form an initial physical barrier and achieve preliminary hemostasis. Afterwards, the double bonds in the gel are further cross-linked by light to form a double-cross-linked hydrogel, thereby enhancing the mechanical properties of the gel itself.

[0050] In the examples of this application, the polyacrylic acid preferably has a molecular weight of 2-100 kDa; the degree of polymerization of the polyethyleneimine preferably is 70 kDa. The polyacrylic acid with a molecular weight of 2-100 kDa can be modified to produce a polyacrylic acid with grafted double bonds that has good solubility in water. The polyethyleneimine with a molecular weight of 70 kDa and the polyacrylic acid with grafted double bonds with a molecular weight of 2-100 kDa can effectively absorb water and self-gel after being formed into powders. The powders can smoothly fuse together and have certain tissue penetration properties.

[0051] In the embodiment of the present application, the molar ratio of the modified polyacrylic acid to the polyethyleneimine is preferably (3:7)-(5:5). By controlling the molar ratio of the modified polyacrylic acid to the polyethyleneimine, the material can have excellent adhesion properties.

[0052] In the embodiments of the present application, the molar ratio of the 2-methylallylamine to the carboxyl group in the polyacrylic acid is 11:(50-200). By controlling the molar ratio of the 2-methylallylamine to the polyacrylic acid, the grafting rate on the polyacrylic acid, the degree of substitution of the double bond modified to PAA, and further the adhesion and solubility of the material can be controlled. The reaction of the 2-methylallylamine and the polyacrylic acid is shown in formula 1:

[0053]

[0054] In the embodiments of the present application, the molar ratio of the dicyclohexyl carbodiimide to the 2-methylallylamine is preferably 10:11.

[0055] In a second aspect, the embodiments of the present application further provide a preparation method of the rapid self-gelling hemostatic powder of the first aspect, and the preparation method comprises:

[0056] The polyacrylic acid, the 2-methylallylamine and the dicyclohexyl carbodiimide are dissolved in N-methyl pyrrolidone for reaction, and the product is collected by separation to obtain the polyacrylic acid with grafted double bonds;

[0057] The polyacrylic acid with grafted double bonds is reacted with the polyethylene imine, and then freeze-drying and grinding are performed to obtain the rapid self-gelling hemostatic powder.

[0058] In the embodiments of the present application, the temperature for the reaction of the polyacrylic acid, the 2-methylallylamine and the dicyclohexyl carbodiimide dissolved in N-methyl pyrrolidone is preferably 40-80°C, and the time is preferably 12-48h. The temperature for the reaction of the polyacrylic acid with grafted double bonds and the polyethylene imine is preferably 25-37°C, and the time is preferably 0.25-24h. By controlling the temperature and time of the reaction, the reaction process can be optimized, and the yield and purity of the self-gelling hemostatic powder can be improved.

[0059] In a third aspect, the present application further provides the use of the rapid self-gelling hemostatic powder prepared by the preparation method of the second aspect in the preparation of a medical hemostatic material. The rapid self-gelling hemostatic powder is used to absorb blood at a wound site, and through electrostatic interaction, the rapid self-gelation at the wound site is achieved to form an initial physical barrier. Further, the lithium salt of phenyl(2,4,6-trimethylbenzoyl) phosphate is used as an initiator to form a covalent cross-linking under the action of 405nm wavelength blue light, and through the double cross-linking hydrogel barrier, the rapid hemostasis is achieved.

[0060] It should be noted that the rapid self-gel hemostatic powder provided by the present application can quickly self-gel, realize adhesion to different tissues, and after secondary cross-linking under light, form covalent bonds to further enhance the mechanical properties of the gel, which has excellent tissue adhesion and hemostatic performance. The hemostatic powder prepared in the present application has good biological safety and shape adaptability, is suitable for soft tissue and other non-compressible bleeding, can quickly form a hemostatic barrier, realizes mechanical enhancement of the hemostatic barrier, and is an ideal choice for clinical bleeding treatment.

[0061] The technical solutions of the present application will be further described below in combination with specific embodiments.

[0062] Embodiment 1

[0063] The present embodiment provides a preparation method of A1-rapid self-gel hemostatic powder (PAA-db / PEI powder), which specifically comprises:

[0064] S101: Dissolve 100kDa polyacrylic acid in N-methylpyrrolidone to make the carboxyl concentration 0.694M. Heat and stir in a 60℃ oil bath pot until completely dissolved. Dissolve 2-methylallylamine in a small amount of NMP. Dissolve dicyclohexyl carbodiimide in a small amount of NMP. Add 2-methylallylamine and dicyclohexyl carbodiimide to the solution in sequence drop by drop under stirring, so that the final concentration of 2-methylallylamine is 0.153M and the final concentration of dicyclohexyl carbodiimide is 0.139M, and react at 60℃ for 24h. Centrifuge the system after reaction, and collect the supernatant. Precipitate the supernatant with diethyl ether, and centrifuge to collect the precipitate. Dissolve the precipitate with methanol, and then precipitate it with diethyl ether again, repeating 2 times. Dry the obtained product in a vacuum oven to obtain polyacrylic acid with grafted double bonds (PAA-db).

[0065] S102: Prepare 1% PAA-db solution and 1% polyethyleneimine solution. Slowly drop the PAA-db solution into the polyethyleneimine solution by a microsyringe pump under stirring, and the volume ratio of the two is 4:6. After stirring for a period of time, freeze the obtained composite system with liquid nitrogen, put it into a freeze dryer for freeze-drying for more than three days, grind the product into powder to obtain A1-rapid self-gel hemostatic powder (PAA-db / PEI powder-1).

[0066] In order to verify the successful preparation of polyacrylic acid with grafted double bonds, the prepared PAA-db was tested by nuclear magnetic resonance, and the test results are shown in Figure 1 .

[0067] According to Figure 1 , it can be known that there are peaks of double bonds and peaks of methylene connected with N atoms on the polyacrylic acid with grafted double bonds, which proves that the double bonds are successfully modified on the PAA. And it is calculated that the degree of substitution of the double bonds modified on the PAA is 18.2%.

[0068] Example 2

[0069] The preparation method of the material, the component allocation ratio and the preparation operation, and the process parameters of this embodiment are basically the same as those of Example 1, the difference lies in that the volume ratio of the 1% PAA-db solution and the 1% polyethyleneimine solution in this embodiment is 3:7, and A2-fast self-gelation hemostatic powder (PAA-db / PEI powder-2) is obtained.

[0070] Example 3

[0071] The preparation method of the material, the component allocation ratio and the preparation operation, and the process parameters of this embodiment are basically the same as those of Example 1, the difference lies in that the volume ratio of the 1% PAA-db solution and the 1% polyethyleneimine solution in this embodiment is 5:5, and A3-fast self-gelation hemostatic powder (PAA-db / PEI powder-3) is obtained. And the degree of substitution of the double bond modified to PAA is calculated to be 18.2%.

[0072] Example 4

[0073] The preparation method of the material, the component allocation ratio and the preparation operation, and the process parameters of this embodiment are basically the same as those of Example 3, the difference lies in that the final concentration of 2-methylallylamine in this embodiment is 0.077M, and the final concentration of dicyclohexyl carbodiimide is 0.070M, and A4-fast self-gelation hemostatic powder (PAA-db / PEI powder-4) is obtained. And the degree of substitution of the double bond modified to PAA is calculated to be 9.3%.

[0074] Example 5

[0075] The preparation method of the material, the component allocation ratio and the preparation operation, and the process parameters of this embodiment are basically the same as those of Example 3, the difference lies in that the final concentration of 2-methylallylamine in this embodiment is 0.038M, and the final concentration of dicyclohexyl carbodiimide is 0.035M, and A5-fast self-gelation hemostatic powder (PAA-db / PEI powder-5) is obtained. And the degree of substitution of the double bond modified to PAA is calculated to be 3.7%.

[0076] At the same time, in order to verify the comprehensive performance of the fast self-gelation hemostatic powder prepared in the above examples, the following comparative examples are provided for detailed description.

[0077] Comparative Example 1

[0078] The preparation method of the material, the component allocation ratio and the preparation operation, and the process parameters of this comparative example are basically the same as those of Example 1, the difference lies in that 2-methylallylamine and dicyclohexyl carbodiimide are not added in this comparative example, only polyacrylic acid and polyethyleneimine are used for reaction to prepare B1-hemostatic powder (PAA-db / PEI powder).

[0079] Comparative Example 2

[0080] This comparative example provides a material preparation method, component ratio, preparation operation, and process parameters that are basically the same as those in Example 1, except that in this comparative example, the volume ratio of 1% PAA-db solution and 1% polyethyleneimine solution is 6:4, obtaining B2-hemostatic powder.

[0081] Comparative Example 3

[0082] This comparative example provides a material preparation method, component ratio, preparation operation, and process parameters that are basically the same as those in Example 1, except that in this comparative example, the volume ratio of 1% PAA-db solution and 1% polyethyleneimine solution is 7:3, obtaining B3-hemostatic powder.

[0083] In order to verify the appearance and performance of the rapid self-gelling hemostatic powder, the prepared hemostatic powder was subjected to scanning electron microscopy test. The test results are as follows: Figure 2 shown.

[0084] according to Figure 2 It can be seen that the rapid self-gel hemostatic powder prepared in the present application presents micron-sized particles.

[0085] In order to verify the mechanical properties of the rapid self-gelling hemostatic powder, the mechanical properties were characterized:

[0086] Electrostatically cross-linked ePAA-db / PEI hydrogel: 520 μL of phenyl (2,4,6-trimethylbenzoyl) phosphate lithium salt (5 mg / mL) was added to 280 mg of PAA-db / PEI powder, and the powder quickly gelated to form ePAA-db / PEI hydrogel.

[0087] Double-crosslinked dPAA-db / PEI hydrogel: 520 μL of phenyl (2,4,6-trimethylbenzoyl) lithium phosphate (5 mg / mL) was added to 280 mg of PAA-db / PEI powder. The powder rapidly gelled to form ePAA-db / PEI hydrogel. 405 nm blue light was used to initiate double bond crosslinking in the gel to produce dPAA-db / PEI hydrogel.

[0088] Rheological tests were performed on ePAA-db / PEI hydrogel and dPAA-db / PEI hydrogel using a rotational rheometer. A 25 mm diameter plate was used to perform frequency sweeps on 25 mm diameter disc-shaped hydrogel samples, with a fixed strain of 1% and a frequency range of 0.1-10 Hz. Figure 6 shown.

[0089] according to Figure 6It can be found that the covalent crosslinking of dPAA-db / PEI hydrogel significantly improves its mechanical properties, and its storage modulus (G') increases from 2.2 kPa to 13.2 kPa. In addition, the frequency dependence of dPAA-db / PEI hydrogel is weaker than that of ePAA-db / PEI hydrogel, further confirming its covalent crosslinking network.

[0090] Adhesion performance test: The lap shear strength of ePAA-db / PEI hydrogel and dPAA-db / PEI hydrogel to intestinal skin was tested by lap shear test; the interfacial toughness of ePAA-db / PEI hydrogel and dPAA-db / PEI hydrogel to intestinal skin was tested by T-peel test; the burst pressure of ePAA-db / PEI hydrogel and dPAA-db / PEI hydrogel to pig skin was tested by burst pressure test.

[0091] The glass slide was covered with intestinal skin and fixed on the surface of the glass slide with cyanoacrylate glue, and ePAA-db / PEI hydrogel (40 mg PAA-db / PEI powder was added with 40 μL PBS solution containing phenyl (2,4,6-trimethylbenzoyl) lithium phosphate salt (5 mg / mL)) was placed in the adhesion area (25 mm x 10 mm) of the intestinal skin to obtain the sample of ePAA-db / PEI hydrogel adhering to the tissue. The sample was crosslinked with light of 405 nm for 1 min to obtain the sample of dPAA-db / PEI hydrogel adhering to the tissue. The lap shear strength of ePAA-db / PEI hydrogel and dPAA-db / PEI hydrogel to intestinal skin was tested by mechanical testing machine, and the test speed was 10 mm / min. Lap shear strength = force at adhesion failure / adhesion area.

[0092] The intestinal skin was fixed on the rigid polyethylene terephthalate film with cyanoacrylate glue, 128 mg of PAA-db / PEI powder was weighed and placed in the adhesion area of 20 mm x 40 mm, 128 μL of PBS solution containing phenyl (2,4,6-trimethylbenzoyl) lithium phosphate salt (5 mg / mL) was added, and another piece of PET film with intestinal skin was covered on its surface to obtain the sample of ePAA-db / PEI hydrogel adhering to the tissue. The sample was crosslinked with light of 405 nm for 1 min to obtain the sample of dPAA-db / PEI hydrogel adhering to the tissue. The sample was subjected to 180° peeling by mechanical testing machine, and the test speed was 100 mm / min. Interfacial toughness = 2F / w, where F is the average force of the peeling force in the platform region during peeling, and w is the width of the sample.

[0093] Pigskin was cut into discs approximately 3 cm in diameter. A 3 mm diameter circular hole was punctured in the center. The tissue was then fixed in a cylindrical mold connected to a syringe pump and a pressure gauge, and the device was filled with PBS solution. 40 mg of powder was applied to the surface of the indentation, and 40 μL of a PBS solution containing 5 mg / mL phenyl (2,4,6-trimethylbenzoyl) phosphate lithium salt was added dropwise to obtain a sample of ePAA-db / PEI hydrogel-adhered tissue. This sample was cross-linked using 405 nm light for 1 minute to obtain a sample of dPAA-db / PEI hydrogel-adhered tissue. PBS solution was injected into the device at a rate of 2 mL / min. The pressure in the device was measured, and the pressure at which the seal failed was recorded as the burst pressure.

[0094] In order to verify the effect of double bond grafting degree on the adhesion performance of powder, the prepared A3-fast self-gelling hemostatic powder, A4-fast self-gelling hemostatic powder, and A5-fast self-gelling hemostatic powder were used for lap shear adhesion test on glass. Figure 3 、 Figure 5 The test measured the lap shear adhesion of the powder to the glass slide; Figure 4 、 Figure 11 The lap shear test is a test of the intestine skin.

[0095] Table 1 Shear strength test results of rapid self-gel hemostatic powder

[0096]

[0097] according to Figure 3 It can be seen that the lap shear strength of A3-fast self-gelling hemostatic powder, A4-fast self-gelling hemostatic powder, and A5-fast self-gelling hemostatic powder gradually increases with increasing grafting rate, but their solubility decreases when the final concentration of 2-methylallylamine is higher than 0.153 M. When the final concentration of 2-methylallylamine is lower than 0.076 M, the adhesion effect becomes weaker.

[0098] according to Figure 4 It can be seen that the lap shear adhesion test was carried out on the dPAA-db / PEI hydrogel formed by PAA-db / PEI powder and the PAA / PEI hydrogel directly formed by PAA / PEI powder. The results showed that the adhesion performance of dPAA-db / PEI was better than that of PAA / PEI.

[0099] according to Figure 5It can be seen that the shear strength of A1-fast self-gelling hemostatic powder, A2-fast self-gelling hemostatic powder, A3-fast self-gelling hemostatic powder, B2-hemostatic powder, and B3-hemostatic powder changes significantly with the change of the ratio of PAA-db and PEI. The dPAA-db / PEI hydrogel made of A1-fast self-gelling hemostatic powder has better lap shear strength.

[0100] The mechanical and adhesive properties test results of ePAA-db / PEI hydrogel and dPAA-db / PEI hydrogel formed by A1-fast self-gelling hemostatic powder are shown in Table 2 and Figure 7-11 As shown:

[0101] Table 2 Test results of mechanical properties and adhesion properties of hydrogels

[0102]

[0103] As can be seen from Table 2, after forming the initial physical barrier, the present application further cross-links the double bonds in the photoinitiated gel to form a double-cross-linked hydrogel, which can stably and effectively exert the hemostatic function in a complex physiological environment and match the tissue characteristics to ensure safety and applicability.

[0104] according to Figure 7 and Figure 8 It can be seen that the tensile properties of dPAA-db / PEI hydrogel are better than those of ePAA-db / PEI hydrogel. Figure 7 is the stress-strain curve in the gel tensile test, Figure 8 are the Young's modulus and tensile strength of the gel.

[0105] according to Figure 9 and Figure 10 It can be seen that the compression performance of dPAA-db / PEI hydrogel is better than that of ePAA-db / PEI hydrogel. Figure 9 is the stress-strain curve in the gel compression test, Figure 10 is the compression modulus of the gel and the compressive stress at 80% compression strain.

[0106] according to Figure 11 It can be seen from a that the lap shear strength of dPAA-db / PEI hydrogel on intestinal skin is better than that of ePAA-db / PEI hydrogel. Figure 11 b It can be seen that the interfacial toughness of dPAA-db / PEI hydrogel on intestinal skin is better than that of ePAA-db / PEI hydrogel. Figure 11 c It can be seen that the bursting pressure of dPAA-db / PEI hydrogel on pig skin is stronger than that of ePAA-db / PEI hydrogel.

[0107] Cytotoxicity test was performed using L929 cells: First, a 10% fetal bovine serum (FBS) and 1.0 × 10 5 DMEM medium containing U / L penicillin and 100mg / L streptomycin was used as complete culture medium. 200mg of sterile dPAA-db / PEI hydrogel was soaked in 20mL of complete culture medium and incubated at 37°C for 24h to obtain dPAA-db / PEI hydrogel extract. L929 cells were seeded in a 96-well plate, 3000 cells per well, 100μL of DMEM complete culture medium was added, and incubated at 37°C, 5% CO2 atmosphere for 12h. The DMEM complete culture medium was then replaced with dPAA-db / PEI hydrogel extract and replaced once a day. DMEM complete culture medium without other ingredients was used as a control. After 24h, 48h, and 72h, the cell viability of L929 cells was tested using the live-dead staining method. The live-dead fluorescence staining effect is shown in the figure below. Figure 12 As shown, dPAA-db / PEI hydrogel had no obvious cytotoxicity to L929 cells within 72 h.

[0108] The hemostatic ability of PAA-db / PEI powder was verified using a rat liver incision model: Rats were anesthetized with 2% sodium pentobarbital solution, their abdominal hair was removed, and they were placed on a heating pad during surgery. The liver was exposed via laparotomy. A 1 cm wide, 0.4 cm deep bleeding wound was created in the rat liver using a scalpel. After free bleeding, the blood was immediately wiped away. 100 mg of PAA-db / PEI powder was applied to the wound site, allowing the in situ formation of a dPAA-db / PEI hydrogel. Untreated controls with free bleeding and ePAA-db / PEI hydrogel served as controls. Blood loss was recorded for each group.

[0109] Hemostasis effect chart and blood loss statistics chart Figure 13 As shown in the figure, the dPAA-db / PEI hydrogel group had the lowest bleeding volume compared with the untreated free bleeding group and the ePAA-db / PEI group, indicating that the electrostatic and covalent double cross-links in the dPAA-db / PEI hydrogel provided excellent mechanical strength and adhesion properties, achieving a strong hemostatic seal.

[0110] Therefore, the rapid self-gelling hemostatic powder provided in the present application is prepared by grafting 2-methylallylamine onto polyacrylic acid and then reacting it with polyethyleneimine. It is used to absorb blood at the wound site and rapidly self-gels at the wound through electrostatic interaction to form an initial physical barrier. It further forms covalent crosslinks under the action of phenyl (2,4,6-trimethylbenzoyl) lithium phosphate and 405nm wavelength blue light, thereby achieving rapid hemostasis through a double-crosslinked hydrogel barrier.

[0111] The various embodiments in this specification are described in a progressive manner. The same or similar parts between the various embodiments can be referenced to each other, and each embodiment focuses on the differences from other embodiments.

[0112] The above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit the present application. Although the present application has been described in detail with reference to the aforementioned embodiments, a person skilled in the art should understand that the technical solutions described in the aforementioned embodiments can still be modified, or some or all of the technical features therein can be replaced by equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the present application.

Claims

1. A rapid self-gelling hemostatic powder, characterized in that: Made by reacting modified polyacrylic acid with polyethyleneimine; The modified polyacrylic acid is obtained by grafting 2-methylallylamine onto the polyacrylic acid through a condensation agent; The condensing agent is dicyclohexylcarbodiimide.

2. The rapid self-gelling hemostatic powder according to claim 1, characterized in that: The polyacrylic acid has a molecular weight of 2-100 kDa; The degree of polymerization of the polyethyleneimine is 70 kDa.

3. The rapid self-gelling hemostatic powder according to claim 1, characterized in that: The molar ratio of the modified polyacrylic acid to polyethyleneimine is (3:7)-(5:5).

4. The rapid self-gelling hemostatic powder according to claim 1, characterized in that: The molar ratio of the 2-methylallylamine to the carboxyl group in the polyacrylic acid is 11:(50-200).

5. The rapid self-gelling hemostatic powder according to claim 1, characterized in that: The molar ratio of the dicyclohexylcarbodiimide to 2-methylallylamine is 10:

11.

6. A method for preparing the rapid self-gel hemostatic powder according to any one of claims 1 to 5, characterized in that: The preparation method comprises: Dissolving polyacrylic acid, 2-methylallylamine and dicyclohexylcarbodiimide in N-methylpyrrolidone for reaction, separating and collecting the product to obtain polyacrylic acid grafted with double bonds; The polyacrylic acid grafted with double bonds is reacted with polyethyleneimine, and then freeze-dried and ground to obtain the rapid self-gel hemostatic powder.

7. The method for preparing the rapid self-gelling hemostatic powder according to claim 6, characterized in that: The temperature for reacting the polyacrylic acid, 2-methylallylamine and dicyclohexylcarbodiimide in N-methylpyrrolidone is 40-80° C. and the reaction time is 12-48 hours.

8. The method for preparing the rapid self-gelling hemostatic powder according to claim 6, characterized in that: The temperature for reacting the polyacrylic acid grafted with double bonds with polyethyleneimine is 25-37° C. and the time is 0.25-24 hours.

9. Use of the fast self-gelling hemostatic powder prepared by the preparation method according to any one of claims 6 to 8 in the preparation of medical hemostatic materials.

10. The use according to claim 9, characterized in that: The rapid self-gelling hemostatic powder is used to absorb blood at the wound site, rapidly self-gels at the wound site through electrostatic interaction to form an initial physical barrier, and further forms covalent cross-links under the action of phenyl (2,4,6-trimethylbenzoyl) phosphate lithium salt and 405nm wavelength blue light, thereby achieving rapid hemostasis through a double-cross-linked hydrogel barrier.

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