Analgesic hemostatic material and preparation method thereof

Abstract

The invention relates to the technical field of hemostatic materials, in particular to an analgesic hemostatic material and a preparation method thereof. The analgesic hemostatic material provided by the invention comprises hydrogel and an analgesic drug loaded on the hydrogel, the hydrogel is three-dimensional network gel formed by crosslinking biguanide chitosan and polyvinyl alcohol. The analgesic and hemostatic material provided by the invention has the functions of analgesia and wound healing promotion while having a hemostatic function, overcomes the defect that an analgesic drug and a hemostatic material are used separately in the prior art, and is suitable for wound treatment.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of hemostatic materials, in particular to a pain-relieving hemostatic material and a preparation method thereof. BACKGROUND

[0002] Hemostatic material refers to a kind of medical product specially designed for rapid control of bleeding. Common local hemostatic materials can be divided into biological sources, such as fibrinogen, thrombin, etc.; chemical synthesis, such as acrylic acid, polyethylene glycol, etc.; inorganic compounds, such as zeolite, kaolin, etc. hemostatic materials; polysaccharides, such as chitosan, cellulose, alginate, etc. These hemostatic materials are all aimed at quickly sealing the wound and promoting coagulation to prevent excessive blood loss. Although the above-mentioned materials can effectively stop bleeding, they cannot have the functions of pain relief and wound healing promotion at the same time. SUMMARY

[0003] Therefore, the present application aims to provide a pain-relieving hemostatic material with the functions of hemostasis, pain relief and wound healing promotion.

[0004] To achieve the above-mentioned application purpose, the present application provides the following technical solutions:

[0005] The present application provides a pain-relieving hemostatic material, which comprises a hydrogel and a pain-relieving drug loaded on the hydrogel; the hydrogel is a three-dimensional network gel formed by cross-linking of a biguanide-based chitosan and polyvinyl alcohol.

[0006] Preferably, the drug loading rate of the pain-relieving hemostatic material is 30-35%.

[0007] Preferably, the pain-relieving drug comprises flurbiprofen.

[0008] The present application provides a preparation method of the pain-relieving hemostatic material described in the above-mentioned solution, which comprises the following steps:

[0009] Mixing an aqueous solution of polyvinyl alcohol, an aqueous acetic acid solution of biguanide-based chitosan and a cross-linking agent solution, carrying out cross-linking reaction and repeatedly freezing and thawing until a hydrogel is formed;

[0010] Adding a dissolved solution of a pain-relieving drug to the hydrogel, freeze-drying to obtain the pain-relieving hemostatic material.

[0011] Preferably, the mass ratio of polyvinyl alcohol to biguanide-based chitosan is 1-2:1.

[0012] Preferably, the mass concentration of polyvinyl alcohol in the aqueous solution of polyvinyl alcohol is 5-10%.

[0013] The mass concentration of biguanide-based chitosan in the aqueous acetic acid solution of biguanide-based chitosan is 2-2.5%, and the mass concentration of acetic acid in the aqueous acetic acid solution is 1-2%.

[0014] Preferably, the cross-linking reaction comprises stirring and standing in sequence, the stirring time is 1-3h, and the standing time is 48-72h.

[0015] Preferably, the solvent of the dissolved solution of the analgesic drug is anhydrous ethanol and PBS solution, the volume ratio of the anhydrous ethanol and PBS solution is 2-3:1, and the concentration of the analgesic drug in the dissolved solution of the analgesic drug is 30-40mg / mL.

[0016] Preferably, the repeated freezing and thawing is repeated freezing and thawing; the temperature of each freezing is-20 to-40℃, and the time is 12-24h; the temperature of each thawing is 20-40℃, and the time is 6-12h.

[0017] Preferably, the preparation method of the biguanide-based chitosan comprises the following steps: dissolving chitosan in a hydrochloric acid solution to obtain a chitosan solution; mixing the chitosan solution with dicyandiamide to perform a modification reaction, and performing solid-liquid separation after the formed biguanide-based chitosan is precipitated to obtain the biguanide-based chitosan.

[0018] The present application provides an analgesic hemostatic material, comprising a hydrogel and an analgesic drug loaded on the hydrogel; the hydrogel is a three-dimensional network gel formed by cross-linking biguanide-based chitosan and polyvinyl alcohol. In the present application, the hydrogel has a three-dimensional network structure similar to a sponge, and this structure endows it with good tissue compatibility, can be used as a carrier of an analgesic drug, and improves the stability of the analgesic drug. In addition, the hydrogel can swell after absorbing liquid, and when applied to a wound surface, the swelling property of the hydrogel helps to close the wound, forms a physical barrier, and reduces bleeding. Moreover, the biguanide-based chitosan structure in the hydrogel can effectively promote wound healing. The present application loads the analgesic drug on the hydrogel, and the hydrogel drug loading system can control the release rate of the analgesic drug in the body, realizes sustained release, which is particularly important for analgesic drugs that need to maintain stable drug concentration, can reduce the frequency of drug administration, improve the medication compliance of patients, and reduce possible side effects. The analgesic hemostatic material provided by the present application has hemostatic function and analgesic effect, solves the drawbacks of separate use of analgesic drugs and hemostatic materials in the prior art, and is suitable for trauma treatment.

[0019] The present application provides a preparation method of the analgesic hemostatic material described in the above scheme, which is simple in steps and easy to realize industrial production. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 The infrared spectrum of biguanide-based chitosan and chitosan;

[0021] Figure 2 The drug release curve of the analgesic hemostatic material prepared in Example 1;

[0022] Figure 3 Figure 4 is a graph of the results of a cytotoxicity test, in which "***" represents p<0.0001, indicating that the difference is very significant;

[0023] Figure 4 Figure 5 is a graph of the results of an analgesic experiment;

[0024] Figure 5 Figure 6 is a photograph of a liver bleeding experiment, in which "*" represents p<0.05, indicating that the difference is relatively significant;

[0025] Figure 6 Figure 7 is a graph of the amount of blood loss, in which "*" represents p<0.05, indicating that the difference is relatively significant, and "**" represents p<0.01, indicating that the difference is significant;

[0026] Figure 7 Figure 8 is a graph of the time of hemostasis, in which "*" represents p<0.05, indicating that the difference is relatively significant, and "**" represents p<0.01, indicating that the difference is significant;

[0027] Figure 8 Figure 9 is a photograph of wound repair;

[0028] Figure 9 Figure 10 is the results of an antibacterial experiment. DETAILED DESCRIPTION

[0029] The present application provides an analgesic hemostatic material, comprising a hydrogel and an analgesic drug loaded on the hydrogel; the hydrogel is a three-dimensional network gel formed by cross-linking a biguanide-based chitosan and polyvinyl alcohol.

[0030] In the present application, the drug loading rate of the analgesic hemostatic material is preferably 30-35%, and in a specific embodiment, is 31.4%. In the present application, the analgesic drug preferably comprises flurbiprofen. In the present application, the calculation method of the drug loading rate is = (mass of analgesic drug / mass of hydrogel after lyophilization) x 100%.

[0031] In the present application, the encapsulation efficiency of the analgesic hemostatic material is preferably 70-75%, and in a specific embodiment, is 73%.

[0032] Current trauma hemostatic materials and analgesic drugs are usually used separately. This separate use method has some inconveniences. First, multiple different products need to be carried, increasing the carrying burden. Second, in an emergency, different products need to be used separately, increasing the time and complexity of handling trauma. In addition, if the trauma causes severe pain, the process of using the hemostatic material may cause more pain to the injured person. The invention loads analgesic drugs onto hydrogel to obtain a hemostatic and analgesic material with hemostatic and analgesic effects, solving the disadvantages of separate use of current analgesic drugs and hemostatic materials.

[0033] In addition, existing hemostatic materials do not have the function of promoting wound healing. However, by using bis-guanidinium chitosan to construct hydrogel, the invention utilizes the antibacterial properties, tissue regeneration promotion, and immune regulation functions of bis-guanidinium structure to further endow the analgesic hemostatic material with the function of promoting wound healing. The specific action modes include:

[0034] Antibacterial performance: Bis-guanidinium chitosan can effectively inhibit the growth of bacteria and reduce the risk of infection, which is a very important step in the wound healing process. By effectively controlling infection, a more favorable environment for wound healing can be provided.

[0035] Moist environment: Bis-guanidinium chitosan can help maintain the local moist environment of the wound, and a moist wound environment helps cell migration and proliferation, promoting the regeneration of epithelial cells and other cells. This is crucial for speeding up the wound healing process.

[0036] Biocompatibility and low cytotoxicity: Bis-guanidinium chitosan has good biocompatibility and low cytotoxicity, and can be well compatible with human tissues without causing significant immune response or other side effects.

[0037] Promoting tissue regeneration: By regulating cell behavior such as fibroblast proliferation and migration, bis-guanidinium chitosan can support and promote tissue regeneration. This provides important support for wound healing, especially for the healing of complex wounds.

[0038] Immune regulation: Bis-guanidinium chitosan may play a role in regulating immune response, helping to reduce inflammation and thus supporting the healing process.

[0039] In the present application, the hydrogel has a sponge-like three-dimensional network structure, which endows it with good tissue compatibility, can be used as a carrier of analgesic drugs (whether local or systemic drugs, whether hydrophilic or hydrophobic drugs, the hydrogel can effectively wrap), and improves the stability of analgesic drugs. The hydrogel will swell rapidly under water stimulation, and can quickly stop bleeding of various types of bleeding including deep bleeding. In addition, the hydrogel is soft in texture, making it more comfortable when contacting body tissue and reducing discomfort, which is particularly important for drug carriers that need to be used for a long time, and can improve the comfort and use experience of patients.

[0040] The present application provides a preparation method of the analgesic and hemostatic material described in the above scheme, comprising the following steps:

[0041] Mixing the aqueous solution of polyvinyl alcohol, the aqueous acetic acid solution of biguanide-based chitosan and the crosslinking agent solution, carrying out crosslinking reaction and repeatedly freezing and thawing until the hydrogel is formed;

[0042] Adding the dissolved solution of analgesic drugs into the hydrogel, freeze-drying to obtain the analgesic and hemostatic material.

[0043] In the present application, unless otherwise specified, the raw materials used are commercially available products well known in the art.

[0044] The source of biguanide-based chitosan will be described first.

[0045] In the present application, the biguanide-based chitosan is preferably obtained by self-preparation; the preparation method of the biguanide-based chitosan preferably comprises the following steps: dissolving chitosan in a hydrochloric acid solution to obtain a chitosan solution; mixing the chitosan solution with dicyandiamide to carry out a modification reaction, and then solid-liquid separation after the formed biguanide-based chitosan is precipitated to obtain the biguanide-based chitosan.

[0046] In the present application, the chitosan is dissolved in a hydrochloric acid solution to obtain a chitosan solution.

[0047] In the present application, the degree of deacetylation of the chitosan is preferably ≥ 95%, and the viscosity is preferably 100-200 mpa·s. In the present application, the mass concentration of the hydrochloric acid solution is preferably 1%. The present application does not have special requirements for the amount of the hydrochloric acid solution, which can completely dissolve the chitosan. In the examples of the present application, specifically, 2 g of chitosan is dissolved in 100 mL of hydrochloric acid solution. The present application does not have special requirements for the dissolving process.

[0048] After obtaining the chitosan solution, the present application mixes the chitosan solution with dicyandiamide to carry out a modification reaction, and then solid-liquid separation after the formed biguanide-based chitosan is precipitated to obtain the biguanide-based chitosan.

[0049] In the present application, the mass ratio of chitosan to dicyandiamide in the chitosan solution is preferably 1.5-2:1, and in specific embodiments, it can be 1.5:1, 1.8:1, 1.9:1 or 2:1; the mixing preferably comprises adding dicyandiamide into the chitosan solution. In the present application, the temperature of the modification reaction is preferably 90-100℃, and the time is preferably 2-6h. In specific embodiments, the temperature of the modification reaction can be 90℃, 95℃ or 100℃, and the time of the modification reaction can be 2h, 3h, 4h, 5h or 6h. The modification reaction is preferably carried out under stirring. In the present application, during the modification reaction, the cyano group (-C≡N) of dicyandiamide reacts with the amino group (-NH2) of chitosan to form dicyandiamide-modified chitosan.

[0050] In the present application, the structure of the dicyandiamide-modified chitosan is shown in Formula 1:

[0051]

[0052] In the present application, the dicyandiamide-modified chitosan formed in the modification reaction is precipitated and then subjected to solid-liquid separation to obtain the dicyandiamide-modified chitosan.

[0053] In the present application, the dicyandiamide-modified chitosan is preferably precipitated by placing the system after the modification reaction in ice ethanol. In the present application, the temperature of the ice ethanol is preferably -20 to -40℃.

[0054] The present application does not have special requirements for the solid-liquid separation method, and the solid-liquid separation method known in the art can be used, such as centrifugation.

[0055] After the solid-liquid separation is completed, the obtained solid is preferably washed with ethanol and then vacuum dried. The present application does not have special requirements for the conditions of the vacuum drying, and the dicyandiamide-modified chitosan can be dried completely. In the embodiments of the present application, the vacuum drying is specifically carried out in a vacuum drying oven at 60℃ for 24h.

[0056] The preparation method of the analgesic hemostatic material will be described below.

[0057] In the present application, the aqueous solution of polyvinyl alcohol, the aqueous acetic acid solution of dicyandiamide-modified chitosan and the crosslinking agent solution are mixed, and then subjected to crosslinking reaction and repeated freezing and thawing until a hydrogel is formed.

[0058] In the present application, the polyvinyl alcohol is preferably PVA-105, and the relative molecular weight is preferably 47000. In the present application, the mass concentration of polyvinyl alcohol in the aqueous solution of polyvinyl alcohol is preferably 5-10%, and in specific embodiments, it can be 5%, 6%, 7%, 8%, 9% or 10%. In the present application, the aqueous solution of polyvinyl alcohol is preferably obtained by dissolving polyvinyl alcohol in hot water at 80℃.

[0059] In the present application, the mass concentration of the biguanide-based chitosan in the aqueous acetic acid solution of the biguanide-based chitosan is preferably 2-2.5%, and the solvent is an aqueous acetic acid solution, and the mass concentration of acetic acid in the aqueous acetic acid solution is preferably 1-2%. The present application specifically dissolves the biguanide-based chitosan in the aqueous acetic acid solution to obtain the acetic acid solution of the biguanide-based chitosan.

[0060] In the present application, the mass ratio of the polyvinyl alcohol to the biguanide-based chitosan is preferably 1-2:1, and in specific embodiments, it can be 1:1, 1.3:1, 1.5:1 or 2:1.

[0061] In the present application, the mass concentration of the crosslinking agent in the crosslinking agent solution is preferably 50%, and the solvent of the crosslinking agent solution is preferably water. In the present application, the crosslinking agent preferably includes one or more of glutaraldehyde, tannic acid and oxidized dextran.

[0062] In the present application, the ratio of the mass of the crosslinking agent in the crosslinking agent solution to the total volume of the aqueous polyvinyl alcohol solution and the aqueous acetic acid solution of the biguanide-based chitosan is preferably 0.001-2 mg:1 mL (i.e. 0.1-2% w / v), and in specific embodiments, it is 0.05%.

[0063] In the present application, the mixing of the aqueous polyvinyl alcohol solution, the acetic acid solution of the biguanide-based chitosan and the glutaraldehyde solution preferably includes: first mixing the aqueous polyvinyl alcohol solution and the aqueous acetic acid solution of the biguanide-based chitosan and stirring for 2 h, and then adding the crosslinking agent solution.

[0064] In the present application, the crosslinking reaction is preferably carried out at room temperature (20-40℃), and the crosslinking reaction preferably includes: stirring and standing in sequence; the stirring time is preferably 1-3 h, and in specific embodiments, it can be 1 h, 2 h or 3 h; and the standing time is preferably 48-72 h, and in specific embodiments, it can be 48 h, 56 h, 64 h or 72 h.

[0065] After the cross-linking reaction is completed, the product obtained is subjected to repeated freezing and thawing until a hydrogel is formed. In the present application, the repeated freezing and thawing is preferably repeated freezing and thawing; the temperature of each freezing is preferably -20 to -40°C, and the time of each freezing is preferably 12 to 24 hours; the temperature of each thawing is preferably 20 to 40°C, and the time of each thawing is preferably 6 to 12 hours. In the embodiments of the present application, the temperature of each freezing can be specifically -20°C, -30°C or -40°C, the time of each freezing can be specifically 12 hours, 18 hours, 20 hours or 24 hours, the temperature of each thawing can be specifically 20°C, 30°C or 40°C, and the time of each thawing can be specifically 6 hours, 8 hours, 10 hours or 12 hours. In the present application, the hydroxyl groups of polyvinyl alcohol and the amino groups of the biguanide-based chitosan are more easily cross-linked by hydrogen bonding through repeated freezing and thawing, and the molecular chains are tightly aggregated by extrusion, forming hydrogen bonding and microcrystalline regions, and the microcrystalline regions of polyvinyl alcohol and the hydrogen bonding / electrostatic interaction of chitosan together stabilize the gel structure.

[0066] After the hydrogel is obtained, a solution of analgesic drug is added to the hydrogel, and the solution is freeze-dried to obtain the analgesic hemostatic material.

[0067] In the present application, the solvent of the solution of analgesic drug is preferably anhydrous ethanol and PBS solution, the volume ratio of the anhydrous ethanol and PBS solution is preferably 2-3:1, and the pH value of the PBS solution is preferably 7.4; the PBS solution is added in the present application to dilute the anhydrous ethanol. In the present application, the concentration of analgesic drug in the solution of analgesic drug is preferably 30-40 mg / mL, and in specific embodiments, it can be 30 mg / mL, 33 mg / mL, 35 mg / mL, 38 mg / mL or 40 mg / mL.

[0068] The solution of analgesic drug is preferably added dropwise to the hydrogel in the present application. In the present application, the shape of the hydrogel can be selected as needed, and in the embodiments of the present application, the hydrogel is cylindrical with a diameter of 8 mm and a height of 3 mm.

[0069] After the solution of analgesic drug is added, the present application preferably places it at room temperature to volatilize the ethanol and then rinses it with water. The present application does not have special requirements for the time of placing at room temperature, and the ethanol can be completely volatilized, which can be 30 minutes or 24 hours.

[0070] The present application does not have special requirements for the freeze-drying conditions, and the freeze-drying conditions well known in the art can be used.

[0071] The analgesic hemostatic material and the preparation method thereof provided by the present application are described in detail below in conjunction with the embodiments, but they should not be understood as limiting the scope of protection of the present application.

[0072] Example 1

[0073] 2g of chitosan was dissolved in 100 mL of 1% hydrochloric acid and continuously stirred at room temperature for 30 min. Subsequently, 1.06g of dicyandiamide was added to the above solution, and then the modification reaction was carried out again at 90°C for 2h. After the reaction was completed, the concentrated solution was poured into 200 mL of ice ethanol (temperature -30°C), and then centrifuged at 4000g for 20 min to obtain biguanide chitosan. The obtained biguanide chitosan was washed with ethanol several times, and finally dried by a 60°C vacuum drying oven for 24h.

[0074] Polyvinyl alcohol (specifically PVA-105, the relative molecular weight is preferably 47000) was dissolved in hot water at 80°C to prepare a polyvinyl alcohol solution with a mass concentration of 10%; biguanide chitosan was dissolved in 1% acetic acid aqueous solution to prepare a biguanide chitosan solution with a concentration of 2.5%; 1.333 mL of polyvinyl alcohol solution and 4 mL of biguanide chitosan solution were stirred at room temperature for 2h, then 5.333 μL of 50% glutaraldehyde solution was added, stirred at room temperature for 1h, and then placed at room temperature for 72h, then frozen at -20°C for 12h, thawed at room temperature for 6h, and repeated several times until a hydrogel was formed. The hydrogel was cut into a cylindrical hydrogel with a diameter of 8mm and a height of 3mm by a puncher, and was recorded as BCS / PVA.

[0075] 1mg of flurbiprofen (FB for short) was dissolved in 20μL of anhydrous ethanol and 10μL of PBS solution (pH value is 7.4), and was added dropwise into the cylindrical hydrogel. After being placed at room temperature for 24h, it was washed with deionized water, freeze-dried to obtain an analgesic hemostatic material, which was recorded as BCS / PVA@FB.

[0076] Comparative Example 1

[0077] Preparation of CS / PVA:

[0078] Polyvinyl alcohol (specifically PVA-105, the relative molecular weight is preferably 47000) was dissolved in hot water at 80°C to prepare a polyvinyl alcohol solution with a mass concentration of 10%; chitosan was dissolved in 1% acetic acid aqueous solution to prepare a chitosan solution with a concentration of 2.5%; 1.333 mL of polyvinyl alcohol solution and 4 mL of chitosan solution were stirred at room temperature for 2h, then 5.333 μL of 50% glutaraldehyde solution was added, stirred at room temperature for 1h, and then placed at room temperature for 72h, then frozen at -20°C for 12h, thawed at room temperature for 6h, and repeated several times until a hydrogel was formed. The hydrogel was cut into a cylindrical hydrogel with a diameter of 8mm and a height of 3mm by a puncher, and was recorded as CS / PVA.

[0079] Comparative Example 2

[0080] Preparation of BCS / PVA:

[0081] Polyvinyl alcohol (specifically PVA-105, preferably with a relative molecular weight of 47,000) was dissolved in 80°C hot water to prepare a polyvinyl alcohol solution with a mass concentration of 10%; biguanide chitosan was dissolved in 1% acetic acid aqueous solution to prepare a biguanide chitosan solution with a concentration of 2.5%; 1.333 mL of the polyvinyl alcohol solution and 4 mL of the biguanide chitosan solution were stirred at room temperature for 2 hours, and then 5.333 μL of a 50% glutaraldehyde solution was added. The mixture was stirred at room temperature for 1 hour, allowed to stand at room temperature for 72 hours, and then frozen at -20°C for 12 hours, thawed at room temperature for 6 hours, and the freeze-thaw cycle was repeated several times until a hydrogel was formed. The hydrogel was then cut into cylindrical hydrogels with a diameter of 8 mm and a height of 3 mm using a punch, which was recorded as BCS / PVA.

[0082] Infrared characterization

[0083] The infrared characterization of biguanidine chitosan (BCS) and chitosan (CS) was performed. Figure 1 .Depend on Figure 1 It can be seen that BCS is at 1515 and 1615 cm -1 The emergence of a new peak at , indicating the appearance of C = N, indicating the formation of biguanylated chitosan.

[0084] Hydrogel drug release

[0085] The analgesic and hemostatic material prepared in Example 1 was immersed in a PBS solution (pH 7.4) for 24 h, and the content of flurbiprofen in the solution at different times was measured by ultraviolet spectrophotometer to calculate the drug release amount; the results are shown in FIG. Figure 2 .Depend on Figure 2 It can be seen that the analgesic hemostatic material prepared in Example 1 has a drug release time of about 20 hours and a cumulative drug release rate of about 55%, indicating that the analgesic hemostatic material of the present invention can achieve sustained release of analgesics, reduce the frequency of administration, and help improve patients' medication compliance.

[0086] Cytotoxicity

[0087] The analgesic and hemostatic material prepared in Example 1 was subjected to MTT assay to evaluate its cytotoxicity in NIH3T3 cells (mouse embryonic fibroblast cell line). Before the test, all freeze-dried hydrogels (BCS / PVA and BCS / PVA@FB) were extracted in a 37°C constant temperature shaker for 24 hours with an extraction volume ratio of 1:5 between the volume ratio of hydrogel and the volume ratio of DMEM complete medium to obtain hydrogel extracts. The hydrogel extracts were diluted with DMEM complete medium to obtain hydrogel extracts of different concentrations (volume concentrations were 25%, 50%, 75% and 100%, respectively). NIH3T3 cells were seeded in 100 μL DMEM culture medium at a density of 3000 cells / well and pre-cultured at 37°C for 12 hours. Different concentrations of hydrogel extracts were added respectively, and the culture was continued for 24 hours. The cytotoxicity of the foam was evaluated by cell counting. The results are shown in Table 2. Figure 3 .Depend on Figure 3 It can be seen that the non-drug-loaded hydrogel BCS / PVA is non-toxic at all concentrations, and the drug-loaded group BCS / PVA@FB is non-toxic within a concentration of 50% ( Figure 3 The concentration of 0 represents the blank group cultured in DMEM complete medium).

[0088] Analgesia experiment

[0089] The mice were anesthetized with chloral hydrate, and then their backs were shaved and wounds with a diameter of 8 mm were made. The mice were then divided into a blank group, a BCS / PVA group, a FB group, and a BCS / PVA@FB group for treatment. The blank group was given only 100 μL PBS, the BCS / PVA group was given a BCS / PVA hydrogel applied to the wound, the FB group was given a solution of FB with the same drug loading amount dissolved in a small amount of ethanol (20 μL) and then added with 10 μL PBS, which was then dropped onto the wound and covered with a medical surgical patch, and the BCS / PVA@FB group was given a BCS / PVA@FB analgesic and hemostatic material.

[0090] The hot plate method was used to evaluate the response of each group of mice to thermal pain stimulation. The temperature of the thermostatic intelligent hot plate instrument was set to a constant temperature of 55±0.2℃. Once the hot plate reached the set temperature, the plexiglass cover was removed and the mouse was quickly placed on the instrument. The time from the mouse's hind paw contacting the hot plate to the occurrence of any of the following behaviors - lifting, retracting, licking it, or struggling - was recorded as the hind paw withdrawal time, also known as PWL. This indicator can be used as an indicator to assess the thermal pain threshold of mice. The maximum time was set to 60s (critical value) to prevent burns to the mouse paw tissue. Each mouse was measured twice, with an interval of 10 minutes between each measurement, and the average value was taken. The thermal pain threshold latency of each mouse was measured one day before modeling as the baseline thermal pain threshold. The thermal pain threshold was measured 0.5, 1.5, 2, 3.5, 5, 7 and 9 hours after surgery. The %MPE (percent increase in pain threshold) of each mouse was calculated using the following formula 2: %MPE=[(LR-BR)=(MR-BR)]×100% Formula 2, where LR, MR, and BR represent the measurement, maximum (60 seconds), and baseline (~5 seconds) response times, respectively. Figure 4 .from Figure 4 It can be seen that the analgesic effect of the BCS / PVA@FB group is higher than that of the other groups, and the 9hBCS / PVA@FB group is significantly higher than the BCS / PVA group, indicating that the analgesic effect of the hydrogel group loaded with flurbiprofen is better than that of other groups.

[0091] Hemostasis experiment

[0092] Mice (n=16) used in the liver bleeding experiment were randomly divided into 4 groups, namely blank group (Blank), gauze treatment group (Gauze), CS / PVA treatment group and BCS / PVA@FB treatment group. The liver of each mouse was exposed by abdominal incision, and the slurry around the liver was carefully removed to ensure accurate estimation of the blood weight obtained from the hemostatic sample. A pre-weighed filter paper was placed between the plastic film and the liver, and the mouse liver was punctured with a 16G needle on a 30° inclined board to cause bleeding. The diameter of the 16G needle used was 1.6mm, the puncture depth was 2mm, and the depth was kept consistent. Gauze, CA / PVA and freeze-dried BCS / PVA@FB were promptly applied to the bleeding site, and the hemostasis time and blood loss during the hemostasis period were recorded. Photos were taken at 0, 30, 60 and 90s at the bleeding site (see Figure 5 ). Record the hemostasis time of each group. The results are shown in Figure 7 .from Figure 7It can be seen that the BCS / PVA@FB group has the shortest hemostatic time, and there is a significant difference between the gauze group and the blank group, and there is a significant difference between the CS / PVA group and the blank group. The hemostatic effect of the BCS / PVA@FB group loaded with fluorouracil is better than that of other groups. The hemostatic time of the BCS / PVA@FB group is only 131.5±29.8s, which is shortened by nearly 58%, 42% and 13% compared with the blank, gauze and CS / PVA groups, respectively. In addition, the blood loss of the BCS / PVA@FB group is 28.2±9.8mg, which is about 69%, 39% and 39% lower than that of the blank, gauze and CS / PVA groups, respectively (see Figure 6 ).

[0093] Wound repair effect

[0094] First, the mice were anesthetized with chloral hydrate, then the back was shaved, a wound with a diameter of 8mm was cut, and then it was divided into a blank group, a BCS / PVA group, an FB group and a BCS / PVA@FB group for treatment, wherein the blank group was only given 100μL PBS, the BCS / PVA group was to apply BCS / PVA hydrogel to the wound, the FB group was to dissolve the same drug load of FB in a small amount of ethanol (20μL) and then add 10μL PBS to make a solution, which was dropped on the wound and then pasted with a medical surgical tape, and the BCS / PVA@FB group was to apply BCS / PVA@FB analgesic and hemostatic material. After the wound was made, the wound size was observed by taking pictures at 0, 7, 9, 12 and 15 days, and the results are shown in Figure 8 . It can be seen from Figure 8 that compared with other groups, the wound healing speed of the BCS / PVA@FB group is the fastest.

[0095] Antibacterial experiment

[0096] The bacteria were cultured in Luria-Bertani medium at 37°C in a shaking bed overnight. Then 100μL of bacterial suspension was added to 400uL of double distilled water and added to CS / PVA, BCS / PVA and BCS / PVA@FB hydrogels, respectively. Then incubate in a 37°C shaking bed for 12h. After that, dilute the bacterial solution with double distilled water, and inoculate 100μL of each dilution on LB agar plates. After incubation for 24h, the results are shown in Figure 9 .

[0097] It can be seen from Figure 9 that the antibacterial effect of BCS / PVA and BCS / PVA@FB is better than that of CS / PVA, which may be attributed to the fact that the biguanide group (such as -[NH-C(=NH)-NH-]) is highly protonated under physiological conditions, significantly increasing the positive charge density of the molecule, more strongly adsorbing the bacterial membrane, destroying the membrane integrity, leading to content leakage and bacterial death.

[0098] The above merely describes the preferred embodiments of the present application, and it should be pointed out that, for those skilled in the art, several improvements and refinements can be made without departing from the principles of the present application, and these improvements and refinements should also be considered as falling within the protection scope of the present application.

Claims

1. An analgesic hemostatic material, characterized in that: The invention comprises a hydrogel and an analgesic drug loaded on the hydrogel; the hydrogel is a three-dimensional network gel formed by cross-linking biguanide chitosan and polyvinyl alcohol.

2. The analgesic hemostatic material according to claim 1, characterized in that: The drug loading rate of the analgesic and hemostatic material is 30-35%.

3. The analgesic hemostatic material according to claim 1 or 2, characterized in that: The analgesic drugs include flurbiprofen.

4. A method for preparing the analgesic and hemostatic material according to any one of claims 1 to 3, comprising the following steps: An aqueous solution of polyvinyl alcohol, an aqueous solution of biguanide chitosan in acetic acid, and a crosslinking agent solution are mixed, cross-linked, and then repeatedly frozen and thawed until a hydrogel is formed; The analgesic drug solution is added to the hydrogel and freeze-dried to obtain the analgesic hemostatic material.

5. The preparation method according to claim 4, characterized in that The mass ratio of the polyvinyl alcohol to the biguanide chitosan is 1-2:

1.

6. The preparation method according to claim 4 or 5, characterized in that The mass concentration of polyvinyl alcohol in the polyvinyl alcohol aqueous solution is 5-10%; The mass concentration of biguanide chitosan in the acetic acid aqueous solution of biguanide chitosan is 2-2.5%; the mass concentration of acetic acid in the acetic acid aqueous solution is 1-2%.

7. The preparation method according to claim 4 or 5, characterized in that The cross-linking reaction includes stirring and standing in sequence, wherein the stirring time is 1-3 hours, and the standing time is 48-72 hours.

8. The preparation method according to claim 4, characterized in that The solvents of the analgesic drug dissolving solution are anhydrous ethanol and PBS solution, the volume ratio of the anhydrous ethanol and PBS solution is 2-3:1, and the concentration of the analgesic drug in the analgesic drug dissolving solution is 30-40 mg / mL.

9. The preparation method according to claim 4, characterized in that The repeated freezing and thawing is repeated freezing and thawing; the freezing temperature each time is -20 to -40°C and the time is 12 to 24 hours; the thawing temperature each time is 20 to 40°C and the time is 6 to 12 hours.

10. The preparation method according to claim 4, characterized in that The preparation method of the biguanide chitosan comprises the following steps: dissolving chitosan in a hydrochloric acid solution to obtain a chitosan solution; mixing the chitosan solution with dicyandiamide to carry out a modification reaction, precipitating the formed biguanide chitosan, and then performing solid-liquid separation to obtain the biguanide chitosan.

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