A hydrogel with antibacterial and hemostatic functions and a preparation method and application thereof

Abstract

The application discloses a hydrogel with antibacterial and hemostatic functions and a preparation method and application thereof. The composite hydrogel is mainly prepared by mixing polyvinyl alcohol (PVA), natural honey and a nano-silver solution. The preparation method comprises the following steps: firstly, a stable dispersed nano-silver base solution is prepared by using a high-molecular dispersant and a reducing agent, and dialysis purification is performed on the base solution; then, deionized water and PVA are added and heated and stirred until completely dissolved; after cooling, natural honey is added dropwise and uniformly mixed, and physical cross-linking molding is performed by using a freeze-thaw cycle technology after ultrasonic defoaming. The hydrogel can quickly absorb exudates on a wound surface and promote blood coagulation by using the strong and tough porous network of PVA, and can realize multiple synergistic antibacterial under a low-toxicity and safe concentration by combining the microscopic physical damage of nano-silver and the high-osmotic and slightly acidic environment of natural honey. The hydrogel preparation process is green and safe, no chemical cross-linking agent is left, and the hydrogel has excellent dynamic and non-invasive adhesion and long-acting moisturizing properties, and can be widely applied to rapid sealing, hemostasis and healing promotion treatment of complex infected wounds.

Description

Technical Field

[0001] This invention belongs to the field of biomedical materials, specifically relating to a hydrogel with antibacterial and hemostatic functions, its preparation method, and its application. Background Technology

[0002] The skin is the body's first line of defense. When trauma occurs, rapid hemostasis and effective antibacterial treatment are crucial for early care. Traditional dry dressings (such as gauze) not only have poor adhesion to irregular wounds but also tend to adhere rigidly to the wound, easily tearing new tissue during dressing changes and causing secondary damage and rebleeding. At the same time, in the face of infected wounds, over-reliance on antibiotics has led to a serious problem of bacterial resistance.

[0003] In recent years, hydrogels have become ideal dressings due to their ability to maintain a "moist healing" microenvironment. However, they still face significant technical bottlenecks when dealing with complex infected and bleeding wounds: First, it is difficult to balance mechanical strength and adhesive hemostasis. Some highly adhesive hydrogels are prone to breakage and failure, while classic polyvinyl alcohol (PVA) hydrogels, although possessing strong mechanical properties, are biologically inert and lack tissue adhesion and procoagulant activity. Second, bactericidal efficacy and cytotoxicity are mutually restrictive. When relying solely on metal particles such as nano-silver, high concentrations can trigger oxidative stress that kills normal cells and hinders tissue growth; low concentrations are insufficient to address severe infections, and bioactive substances are easily lost.

[0004] Therefore, how to overcome the limitations of existing materials and develop novel composite hydrogels that combine strong mechanical properties, excellent hemostatic and anti-adhesion capabilities, and broad-spectrum and highly effective antibacterial properties at extremely low safe concentrations through the synergistic design of polymer matrices and natural / inorganic components has become a core issue that urgently needs to be addressed in the field of wound repair. Summary of the Invention

[0005] The purpose of this invention is to at least partially solve the technical problems existing in the above-mentioned background art, and to provide a hydrogel with antibacterial and hemostatic functions, its preparation method and application.

[0006] In a first aspect, the present invention provides a method for preparing a hydrogel with antibacterial and hemostatic functions, the method comprising the following steps:

[0007] Step (1): Provide purified nano-silver base solution, which is prepared by reacting silver nitrate solution, polymeric dispersant and reducing agent and then dialysis purification;

[0008] Step (2): Mix the purified nano-silver base solution with deionized water evenly (ultrasonic dispersion can be used as an aid), then add polyvinyl alcohol, heat and stir until completely dissolved to obtain a composite adhesive solution;

[0009] Step (3): Add natural honey to the composite adhesive solution, mix evenly and defoam to obtain the hydrogel precursor solution;

[0010] Step (4): The hydrogel precursor fluid is subjected to freeze-thaw treatment to form a physical cross-linking network, thereby obtaining a hydrogel with antibacterial and hemostatic functions.

[0011] In a preferred embodiment of the present invention, step (1) includes the following steps: mixing silver nitrate solution with polyvinylpyrrolidone as a polymeric dispersant, and adding sodium borohydride solution as a reducing agent dropwise under light-protected and stirring conditions, reacting at room temperature for 1-2 hours. The resulting reaction solution is then purified by dialysis, specifically by placing the reaction solution into a dialysis bag with a molecular weight cutoff of 7000 Da-14000 Da, and dialyzing it in deionized water in the dark for 24-48 hours, changing the deionized water periodically during the process, to obtain purified nano-silver substrate solution.

[0012] In a preferred embodiment of the present invention, in step (1), the concentration of silver nitrate solution is 2 mg / mL, the concentration of sodium borohydride solution is 0.15~0.20 mg / mL, and the ratio of silver nitrate solution, polyvinylpyrrolidone and sodium borohydride solution is 4 mL : (20~40) mg : 4 mL.

[0013] In a preferred embodiment of the present invention, in step (2), the heating and stirring temperature is 85°C to 95°C and the time is 1.5h to 2.5h.

[0014] In a preferred embodiment of the present invention, in step (2), the ratio of the amount of the nano-silver base liquid, deionized water and polyvinyl alcohol is (0.1~1.0) mL : (10~20) mL : (1.0~2.5) g.

[0015] As a preferred embodiment of the present invention, in step (3), the composite adhesive is cooled to 50°C~60°C and then natural honey is added; the defoaming is specifically: ultrasonic defoaming for 3~10 min, and then placed in a water bath at 45°C~55°C for static defoaming.

[0016] In a preferred embodiment of the present invention, in step (3), the ratio of natural honey to polyvinyl alcohol is (1.0~4.0) mL : (1.0~2.5) g.

[0017] As a preferred embodiment of the present invention, in step (4), the freeze-thaw process specifically involves freezing the hydrogel precursor liquid at -15°C to -25°C for 5 to 12 hours, and then thawing it naturally at room temperature.

[0018] In a second aspect, the present invention provides a hydrogel with antibacterial and hemostatic functions prepared by the above-described preparation method.

[0019] In a third aspect, the present invention provides the application of the above-mentioned hydrogel with antibacterial and hemostatic functions in the preparation of medical hemostatic materials, wound dressings or infected wound repair materials.

[0020] The hydrogel with antibacterial and hemostatic functions and its preparation method according to embodiments of the present invention have the following advantages:

[0021] (1) Multi-dimensional synergistic high-efficiency antibacterial and low-toxicity: Nano-silver particles destroy bacterial cell membranes and interfere with DNA by releasing silver ions, while natural honey provides a hypertonic and slightly acidic antibacterial environment. The combination of the two achieves multi-dimensional synergistic bactericidal effect, greatly reducing the effective concentration of nano-silver; at the same time, the natural antioxidants in honey can effectively neutralize local reactive oxygen species (ROS), avoiding the toxicity of high concentrations of metal ions to normal cells, and achieving a unity of selective bactericidal effect and tissue protection.

[0022] (2) Green preparation process and intelligent sustained-release mechanism: This invention uses a freeze-thaw pure physical gelation technology of polyvinyl alcohol (PVA), completely avoiding the toxicity risks of chemical cross-linking agents. The deep integration of natural honey molecules reshapes the hydrogen bond network of PVA, constructing a special microporous framework in situ. This microstructure can act as a natural "smart switch," driving the nano-silver particles to achieve long-term, gradual, and targeted release as the internal sugar molecules dissolve in a gradient, avoiding cellular oxidative damage caused by the sudden release of drugs in traditional silver-loaded dressings.

[0023] (3) Excellent supramolecular mechanical flexibility and dynamic tissue adhesion: Addressing the pain point of traditional hydrogels' difficulty in simultaneously achieving mechanical brittleness and tissue adhesion, this invention utilizes the plasticizing effect of natural macromolecules on the matrix to endow the dressing with extremely high tensile strain capacity, perfectly conforming to the intense activities of complex areas such as joints. At the same time, the abundant free hydroxyl groups on the surface can instantly form dense hydrogen bonds for anchoring upon contact with moist tissue interfaces, achieving firm "wet adhesion" to irregular wounds and various substrates, preventing the dressing from slipping and failing under daily activities or exudate flushing.

[0024] (4) Rapid and Synergistic Hemostasis and Excellent Exudate Management: For clinical bleeding and exudative wounds, this invention exhibits ideal fluid management capabilities. Its internal hypertonic microporous network can instantly absorb wound moisture, rapidly concentrating platelets and coagulation factors locally. Combined with the dense adhesion on the surface, it achieves rapid and synergistic hemostasis through physical sealing and physiological coagulation. At the same time, based on its excellent wet swelling and exudate management capabilities, this structure can effectively absorb excess exudate from the wound, helping to maintain a "micro-moist" environment in the wound bed. Unlike traditional dry dressings (such as gauze) that easily cause wound crusting, its water-rich flexible hydrogel network can greatly reduce the risk of dead drying adhesion with newly formed granulation tissue, thus making the dressing removal process gentler and helping to reduce secondary bleeding and mechanical trauma. Attached Figure Description

[0025] Figure 1 Tensile stress-strain curves and wet swelling rates (permeation absorption) of each group of samples were used for quantitative analysis.

[0026] Figure 2 Quantitative analysis diagram and test concept diagram of the in vitro overlap shear adhesion strength of each group of samples.

[0027] Figure 3 Macroscopic adhesion images of the full-component samples on different substrates and human skin surfaces;

[0028] Figure 4 Photographs of a mouse liver hemorrhage model and a graph showing quantitative analysis of intrahepatic hemorrhage.

[0029] Figure 5 Photographs and bar charts of the in vitro blood clot index (BCI) test results for each group;

[0030] Figure 6 Photographs of centrifuge tubes used for hemolysis testing of extracts from each group, and bar charts for quantitative analysis of hemolysis rate;

[0031] Figure 7 Photographs of plate colony counts after co-incubation of each group of hydrogels with various clinical pathogens (including methicillin-resistant Staphylococcus aureus MRSA, Staphylococcus aureus Sa, Staphylococcus albus W, and Escherichia coli E. coli).

[0032] Figure 8 A bar chart showing the quantitative analysis of the survival rate of each group of hydrogels against the above-mentioned pathogens;

[0033] Figure 9 Fluorescence micrographs of live / dead cells after culturing mouse fibroblasts (MEF) and mouse preadipocytes (3T3) with different extracts;

[0034] Figure 10 Quantitative analysis of cell viability of MEF and 3T3 cells after culturing with different concentrations of extract for 1, 3, and 5 days. Detailed Implementation

[0035] The technical solution of the present invention will be further described in detail below through embodiments and in conjunction with the accompanying drawings. In this specification, the same or similar reference numerals indicate the same or similar components. The following description of the embodiments of the present invention with reference to the accompanying drawings is intended to explain the overall inventive concept of the present invention and should not be construed as a limitation thereof.

[0036] An embodiment of the present invention provides a method for preparing a hydrogel with antibacterial and hemostatic functions, the preparation method comprising the following steps:

[0037] Step (1) provides a purified nano-silver substrate solution, which is prepared by in-situ reaction of silver nitrate solution, polymeric dispersant and reducing agent in liquid phase and purification by dialysis.

[0038] Specifically, the preparation method of the nano-silver base solution is as follows: silver nitrate is dissolved in deionized water, and polyvinylpyrrolidone (PVP) as a polymeric dispersant is added and stirred to dissolve; then sodium borohydride solution as a reducing agent is added dropwise under light-protected conditions, and after reacting at room temperature for 1-2 hours, the reaction solution is placed in a dialysis bag for light-protected dialysis purification to obtain purified nano-silver base solution.

[0039] In some embodiments of the present invention, the concentration of the silver nitrate solution is 1.5-2.5 mg / mL. For example, 1.5 mg / mL, 1.8 mg / mL, 2.0 mg / mL, 2.2 mg / mL, and 2.5 mg / mL. Preferably, it is 2.0 mg / mL. The concentration of the sodium borohydride solution is 0.15-0.20 mg / mL, preferably 0.18 mg / mL.

[0040] In some embodiments of the present invention, the mass ratio of the polymeric dispersant polyvinylpyrrolidone (PVP) to silver nitrate is (2-5):1. For example, 2:1, 3:1, 3.75:1, 4:1, 5:1. Preferably, it is 3.75:1 (i.e., 0.03g PVP corresponds to 0.008g silver nitrate). The long macromolecular chains of PVP can coat the surface of the generated silver nanoparticles, effectively preventing the aggregation of silver nanoparticles through steric hindrance, and ensuring their uniform dispersion in the subsequent hydrogel network.

[0041] In some embodiments of the present invention, the molecular weight cutoff of the dialysis bag used for dialysis purification is 7000 Da-14000 Da, preferably 7000 Da. The dialysis time is 24h-72h, for example 24h, 36h, 48h, 72h, preferably 48h. Through long-term dialysis with a specific molecular weight cutoff, residual borate byproducts and unreacted free metal ions in the reaction system can be completely filtered out, cutting off the potential source of cytotoxicity of traditional metal dressings at the source.

[0042] Step (2) After mixing the purified nano-silver base solution with deionized water evenly, add polyvinyl alcohol (PVA) and heat and stir to obtain composite adhesive solution.

[0043] In some embodiments of the present invention, the ratio of purified nano-silver substrate solution, deionized water, and polyvinyl alcohol is (0.1-1.0) mL : (10-20) mL : (1.0-2.5) g. For example, 0.2 mL : 14.8 mL : 1.5 g, 0.6 mL : 14.4 mL : 2.0 g, and 1.0 mL : 14.0 mL : 2.5 g. A preferred ratio is 0.6 mL of purified nano-silver substrate solution, 14.4 mL of deionized water, and 2.0 g of polyvinyl alcohol.

[0044] Specifically, in step (2), the heating and stirring temperature is 85-95°C, preferably 90°C; the stirring time is 1.5h-2.5h, preferably 2h. Before this high-temperature stage, the nano-silver base solution is ultrasonically mixed with deionized water (e.g., ultrasonic for 3-5 min) to further ensure the high dispersion of nano-silver in the PVA matrix.

[0045] After cooling in step (3), natural honey is added to the composite adhesive solution, mixed evenly and defoamed to obtain the hydrogel precursor solution.

[0046] In some embodiments of the present invention, the composite adhesive solution is naturally cooled to 50-60°C (preferably 55°C) before natural honey is added. The volume of natural honey added accounts for 5-15% (v / v) of the total liquid phase volume. For example, 5% v / v, 8% v / v, 10% v / v, 12% v / v, 15% v / v. Preferably, it is 10% v / v (for example, 1.67 mL of natural honey is added when the total liquid phase is approximately 15 mL).

[0047] Step (4) The hydrogel precursor fluid is subjected to freeze-thaw treatment to form a physical cross-linking network, thereby obtaining a hydrogel with antibacterial and hemostatic functions.

[0048] Specifically, the freezing-thawing conditions are as follows: freeze at -15°C to -25°C (preferably -20°C) for 8-12 hours, and then take it out and thaw naturally at room temperature to form the desired shape.

[0049] As a medical dressing for complex infected bleeding wounds, the composite hydrogel prepared in this invention exhibits excellent multifunctionality through the synergistic microstructure and complementary biochemical mechanisms among its components.

[0050] During freeze-thaw cycles, polyvinyl alcohol (PVA) forms a dense, physically cross-linked porous network through localized crystallization of its molecular chains and strong intermolecular hydrogen bonding. This process completely avoids the introduction of traditional chemical cross-linking agents such as glutaraldehyde, endowing the hydrogel with excellent biocompatibility and high mechanical toughness, effectively absorbing wound exudate and maintaining wound moisture.

[0051] Natural honey is rich in high concentrations of fructose and glucose, which act as natural polymer plasticizers, interspersed between PVA molecular chains, disrupting some rigid crystalline regions and reshaping the hydrogen bond network. This mechanism significantly reduces gel brittleness, giving the material excellent tissue compliance and dynamic wet adhesion. At the same time, the hypertonic microenvironment generated by honey can rapidly absorb percutaneous moisture, locally concentrate platelets and coagulation factors, synergistically accelerating physical closure and physiological coagulation.

[0052] Purified nano-silver continuously releases silver ions (Ag+) into the system, physically puncturing and disrupting bacterial cell membranes. The hypertonic and slightly acidic microenvironment created by honey induces dehydration and inactivation of metabolic enzymes in pathogens, leaving their cell membrane barriers extremely vulnerable. This synergistic physicochemical mechanism enables the hydrogel of this invention to achieve nearly 100% kill of broad-spectrum pathogens, including MRSA, at ultra-low safe concentrations (effective concentration approximately 20 ppm).

[0053] Example 1

[0054] Preparation of the nano-silver substrate: Measure 4 mL of deionized water, add 0.008 g of silver nitrate, and stir magnetically until completely dissolved. Then add 0.03 g of polyvinylpyrrolidone (PVP). Separately, weigh 0.018 g of sodium borohydride and dissolve it in 100 mL of deionized water to prepare a reducing solution. Under light-protected and stirring conditions, slowly add 4 mL of the above sodium borohydride reducing solution to the silver nitrate mixture. After reacting at room temperature in the dark for 1 h, transfer the reaction solution to a dialysis bag with a molecular weight cutoff of 7000 Da and dialyze it in deionized water for 48 h to obtain the purified nano-silver substrate.

[0055] Preparation of the composite hydrogel: 0.6 mL of the purified nano-silver substrate solution was mixed with 14.4 mL of deionized water and sonicated for 5 min. The mixture was placed in a water bath, and 2.0 g of polyvinyl alcohol (PVA) was added. The mixture was heated to 90°C and stirred for 2 h until completely dissolved. After the composite hydrogel solution cooled naturally to 55°C, 1.67 mL of natural honey was added and stirred until homogeneous. After sonication for 5 min and standing in a 50°C water bath to remove bubbles, the hydrogel precursor solution was poured into a mold and frozen at -20°C for 12 h. The mixture was then allowed to thaw naturally at room temperature to obtain the composite hydrogel.

[0056] Example 2

[0057] The same hydrogel preparation method as in Example 1 was used, except for the amount of components: 0.2 mL of the purified silver nanoparticle base solution prepared in Example 1 was mixed with 14.8 mL of deionized water, and 2.0 g of PVA was added; after the solution cooled to 55°C, 1.0 mL of natural honey was added. The remaining preparation steps and freeze-thaw conditions were the same as in Example 1, resulting in a composite hydrogel.

[0058] Example 3

[0059] The same hydrogel preparation method as in Example 1 was used, except for the amount of components: 1.0 mL of the purified silver nanoparticle base solution prepared in Example 1 was mixed with 14.0 mL of deionized water, and 2.0 g of PVA was added; after the solution cooled to 55°C, 1.0 mL of natural honey was added. The remaining preparation steps and freeze-thaw conditions were the same as in Example 1, resulting in a composite hydrogel.

[0060] Example 4

[0061] The same hydrogel preparation method as in Example 1 was used, except for the amount of components: 0.2 mL of the purified silver nanoparticle base solution prepared in Example 1 was mixed with 14.8 mL of deionized water, and 2.0 g of PVA was added; after the solution cooled to 55°C, 2.5 mL of natural honey was added. The remaining preparation steps and freeze-thaw conditions were the same as in Example 1, resulting in a composite hydrogel.

[0062] Example 5

[0063] The same hydrogel preparation method as in Example 1 was used, except for the amount of components: 1.0 mL of the purified silver nanoparticle base solution prepared in Example 1 was mixed with 14.0 mL of deionized water, and 2.0 g of PVA was added; after the solution cooled to 55°C, 2.5 mL of natural honey was added. The remaining preparation steps and freeze-thaw conditions were the same as in Example 1, resulting in a composite hydrogel.

[0064] Comparative Example 1

[0065] 15.0 mL of deionized water was placed in a water bath, and 2.0 g of PVA was added. The mixture was heated to 90°C and stirred for 2 hours until completely dissolved. After cooling and degassing, the mixture was frozen at -20°C for 12 hours and then thawed at room temperature to obtain pure PVA hydrogel. This preparation process did not involve the addition of purified silver nanoparticle substrate solution or honey.

[0066] Comparative Example 2

[0067] 0.6 mL of the purified silver nanoparticle substrate solution prepared in Example 1 was measured and mixed with 14.4 mL of deionized water. 2.0 g of PVA was added, and the mixture was heated to 90°C and stirred for 2 h. After cooling and degassing, the mixture was frozen at -20°C for 12 h and thawed at room temperature to obtain a PVA+Ag hydrogel. No natural honey was added during this preparation process.

[0068] Comparative Example 3

[0069] 15.0 mL of deionized water was placed in a water bath, and 2.0 g of PVA was added. The mixture was heated to 90°C and stirred for 2 hours until completely dissolved. After cooling to 55°C, 1.67 mL of natural honey was added and stirred until homogeneous. After degassing, the mixture was frozen at -20°C for 12 hours and then thawed at room temperature to obtain a PVA+Hny hydrogel. No purified nano-silver substrate solution was added during this preparation process.

[0070] It should be noted that although the ratio of purified nano-silver base solution to natural honey was adjusted in Examples 2-5, and all successfully prepared structurally complete composite hydrogels through physical cross-linking, possessing basic antibacterial and hemostatic functions, preliminary screening revealed that the ratio in Example 1 achieved the optimal balance in terms of mechanical flexibility, tissue adhesion, broad-spectrum antibacterial efficacy, and cell compatibility. Therefore, this invention uses it as the preferred embodiment (i.e., the full-component PVA+Hny+Ag group in the table below).

[0071] Performance Evaluation and Test Cases

[0072] To further demonstrate the beneficial effects of the composite hydrogel of the present invention, the following specific test examples and appendices are provided. Figure 1-10 The performance of Example 1 (the best example, i.e., the full-component PVA+Ag+Hny group) and each comparative example (PBS blank control group, pure PVA group, PVA+Ag group, PVA+Hny group) was compared and explained in detail to further confirm the beneficial effects of the multi-dimensional physicochemical synergistic mechanism of the present invention.

[0073] Test Example 1: Mechanical Properties and Leakage Management Performance Test

[0074] (1) Mechanical tensile testing: Tensile tests were performed on each group of samples using a universal testing machine. For example... Figure 1 As shown on the left, the pure PVA and PVA+Ag groups exhibited lower tensile strains; while the PVA+Hny and PVA+Ag+Hny (full composition) groups with added natural honey showed extremely high mechanical flexibility and significantly improved elongation at break. The intervention of honey molecules effectively remodeled the hydrogen bond network, enabling it to better adapt to irregular wound surfaces and joint movements.

[0075] (2) Exudate absorption (wet swelling) test: such as Figure 1 As shown by the curve on the right, each group of hydrogels was immersed in buffer solution to simulate the wound exudate absorption process. The pure PVA and PVA+Ag groups had lower swelling rates; while the whole component and PVA+Hny groups showed significantly increased swelling rates due to the extremely high osmotic pressure of natural honey and the capillary action generated by the micropores formed in situ after the honey dissolves, ultimately reaching a dynamic equilibrium at around 75%. This demonstrates the dressing's excellent exudate management capabilities, effectively absorbing excess exudate to prevent peri-wound maceration while maintaining an ideal moist healing environment.

[0076] Test Example 2: Tissue Adhesion Performance Test

[0077] The adhesion strength of the samples is tested using an overlap shear test. For example... Figure 2 As shown, the adhesion strength of the whole component and the PVA+Hny group was significantly better than that of the control group without honey. Further macroscopic adhesion experiments ( Figure 3 The results show that the complete sample can adhere firmly to the surfaces of various materials such as stainless steel, glass, wood, plastic, rubber, polytetrafluoroethylene, and medical elastomers, and can closely adhere to human skin. This demonstrates that the remodeling of the internal network endows the material with excellent surface wet adhesion, perfectly balancing firm fixation in clinical applications with painless removal during subsequent dressing changes.

[0078] Test Example 3: In Vitro and In Vitro Hemostatic Performance Test

[0079] (1) In vivo hemostatic performance: The in vivo hemostatic performance of the product was tested using a mouse liver laceration injury model. For example... Figure 4 As shown, the amount of intrahepatic hemorrhage in the untreated control group mice was significant, while the amount of blood loss in the mice treated with the product of Example 1 decreased dramatically (* indicates p<0.05).

[0080] (2) In vitro blood clot index (BCI) test: such as Figure 5As shown, the total component (PVA+Ag+Hny) had the lowest BCI value, significantly better than the medical gauze (Gauze) and pure PVA group (** indicates p<0.01). The above in vitro and in vivo data confirm that the extremely high local osmotic pressure it brings can instantly concentrate platelets in the wound blood, achieving synergistic and rapid physical occlusion and physiological hemostasis.

[0081] Test Example 4: Blood Compatibility (Hemolysis) Test

[0082] like Figure 6 As shown, the Triton positive control group exhibited severe red hemolysis, while the supernatant of all treatment groups, including Example 1, was clear and transparent, with hemolysis rates below 0.05% (far below the safety standard of 5%) (** indicates p<0.01), demonstrating that the product has excellent blood compatibility.

[0083] Test Example 5: Broad-spectrum antibacterial performance test

[0084] like Figure 7 and Figure 8 As shown, the PBS blank group and the pure PVA group plates were covered with colonies; while Example 1 (PVA+Ag+Hny group) achieved a near-0% bacterial survival rate against all Gram-negative / positive bacteria and drug-resistant strains, including methicillin-resistant Staphylococcus aureus (MRSA), Staphylococcus aureus (S. aureus, abbreviated as Sa in the figure), Staphylococcus albus (S. albus, abbreviated as W in the figure), and Escherichia coli (E. coli) (** indicates p<0.01). This demonstrates its excellent broad-spectrum antibacterial efficacy even at extremely low safe concentrations.

[0085] Test Example 6: Cytotoxicity and Compatibility Test

[0086] like Figure 10 As shown, in Example 1, primary fetal mouse fibroblasts (MEFs) and the mouse fibroblast line (NIH3T3) were co-cultured with hydrogels of different concentrations. Even at concentrations as high as 10 mg / mL for 5 consecutive days, the cell viability remained close to 100%, with no significant difference (ns) compared to the PBS control group. Meanwhile, as... Figure 9 As shown in the live / dead fluorescence staining images, the treated cells almost entirely exhibited green fluorescence, representing live cells, with no obvious red dead cells observed. These results fully demonstrate that this process completely overcomes the high cytotoxicity of traditional formulations and possesses excellent tissue-cell compatibility.

[0087] In summary, the hydrogel with antibacterial and hemostatic functions provided by this invention exhibits excellent mechanical flexibility, tissue adhesion, rapid synergistic hemostasis, long-lasting exudate management, and low-toxicity broad-spectrum antibacterial properties through a multi-dimensional physicochemical synergistic mechanism. The results fully demonstrate its enormous clinical application potential as a biomedical material, especially as a healing-promoting dressing for complex infected bleeding wounds.

[0088] The above description is merely a specific embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art should understand that any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for preparing a hydrogel with antibacterial and hemostatic functions, characterized in that, The preparation method includes the following steps: (1) Provide a purified nano-silver base solution, wherein the nano-silver base solution is prepared by reacting silver nitrate solution, polymeric dispersant and reducing agent and then purifying by dialysis; (2) Mix the purified nano-silver base solution with deionized water evenly (ultrasonic dispersion can be used as an aid), then add polyvinyl alcohol, heat and stir until completely dissolved to obtain a composite adhesive solution; (3) Add natural honey to the composite adhesive solution, mix evenly and defoam to obtain the hydrogel precursor solution; (4) The hydrogel precursor fluid is subjected to freeze-thaw treatment to form a physical cross-linking network, thereby obtaining a hydrogel with antibacterial and hemostatic functions.

2. The preparation method according to claim 1, characterized in that, The reaction described in step (1) is as follows: silver nitrate solution is mixed with polyvinylpyrrolidone as a polymeric dispersant, and sodium borohydride solution as a reducing agent is added dropwise under light-protected and stirring conditions, and the reaction is carried out at room temperature for 1 to 2 hours.

3. The preparation method according to claim 1 or 2, characterized in that, The dialysis purification in step (1) specifically involves: placing the reaction solution obtained after the reaction at room temperature into a dialysis bag with a molecular weight cutoff of 7000 Da to 14000 Da, and dialyzing it in deionized water in the dark for 24 to 48 hours, changing the deionized water periodically during the process, to obtain purified nano-silver substrate solution.

4. The preparation method according to claim 2, characterized in that, In step (1), the concentration of silver nitrate solution is 2 mg / mL, and the concentration of sodium borohydride solution is 0.15~0.20 mg / mL; the ratio of the amount of silver nitrate solution, polyvinylpyrrolidone and sodium borohydride solution is 4 mL : (20~40) mg : 4 mL.

5. The preparation method according to claim 1, characterized in that, In step (2), the heating and stirring temperature is 85°C~95°C and the time is 1.5h~2.5h.

6. The preparation method according to claim 1 or 4, characterized in that, In step (2), the ratio of the purified nano-silver base solution, deionized water and polyvinyl alcohol is (0.1~1.0) mL : (10~20) mL : (1.0~2.5) g.

7. The preparation method according to claim 1, characterized in that, In step (3), the composite adhesive is cooled to 50°C~60°C and then natural honey is added; the defoaming is specifically: ultrasonic defoaming for 3~10 min, and then placed in a water bath at 45°C~55°C for static defoaming.

8. The preparation method according to claim 1, characterized in that, In step (3), the ratio of natural honey to polyvinyl alcohol is (1.0~4.0) mL : (1.0~2.5) g.

9. The preparation method according to claim 1, characterized in that, In step (4), the freeze-thaw process specifically involves freezing the hydrogel precursor solution at -15°C to -25°C for 5 to 12 hours, followed by natural thawing and shaping at room temperature.

10. A hydrogel with antibacterial and hemostatic functions prepared by the preparation method according to any one of claims 1-9.

11. The application of a hydrogel with antibacterial and hemostatic functions as described in claim 10 in the preparation of medical hemostatic materials, wound dressings, or infected wound repair materials.

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