Natural polysaccharide copper-based antibacterial hydrogel as well as preparation method and application thereof

Abstract

The invention provides natural polysaccharide copper-based antibacterial hydrogel as well as a preparation method and application thereof. The natural polysaccharide copper-based antibacterial hydrogel is prepared from the following raw materials in parts by weight: 4-9 parts of sesbania gum and derivatives thereof; 6-9 parts of an activator; 0.06 to 0.12 part of a crosslinking active filling agent; 1-5 parts of a cross-linking agent; 65 to 85 parts of deionized water; and 0.4 to 1.1 parts of an antibacterial agent. The problems that an existing natural polysaccharide antibacterial hydrogel is poor in antibacterial performance, poor in water absorption and prone to being adhered to the surface of a wound are solved. The hydrogel has the advantages of good biocompatibility, strong water absorption, water retention and bacterium breeding prevention effects, and efficient and long-acting antibacterial performance.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of biological medicine, and particularly relates to a natural polysaccharide copper-based antibacterial hydrogel, a preparation method and application. BACKGROUND

[0002] Bacterial infection at a skin wound is one of the severe challenges faced by the clinical medical field. The breeding and reproduction of bacteria in the local wound not only significantly delays the self-repairing process of the skin tissue, but also may cause infection symptoms such as redness and inflammation of the wound, and even may cause complications such as abscess and sepsis, which directly threatens the health and even the life safety of the patient. In clinical practice, a medical dressing is a core tool for wound care, and its main function is to cover the wound surface to build a physical protection barrier, so as to effectively block the invasion of external microorganisms and avoid primary infection or secondary pollution of the wound. At the same time, the dressing needs to have the ability to absorb wound exudates to maintain the moist microenvironment of the local wound. This environment is confirmed to be a key condition for promoting the migration of epithelial cells and accelerating the growth of granulation tissue, and is crucial for improving the efficiency of wound healing.

[0003] The natural polysaccharide antibacterial hydrogel dressing is a new type of wound dressing developed rapidly in recent years, and has significant advantages compared with traditional gauze, defatted cotton and other dressings: the three-dimensional network structure of the natural polysaccharide antibacterial hydrogel dressing endows excellent water retention performance and flexibility, can closely fit the contour of the wound and is not easy to damage the new tissue; at the same time, the natural polysaccharide (such as chitosan, hyaluronic acid, etc.) itself has excellent biocompatibility and biodegradability, can reduce the foreign body reaction and reduce the discomfort of the patient; in addition, the natural polysaccharide molecular chain is rich in active sites such as hydroxyl and amino groups, and is easy to optimize its performance through chemical modification or physical modification, and has a broad application prospect in the field of medical dressings.

[0004] However, the current existing natural polysaccharide antibacterial hydrogel dressing still has three core technical defects in actual clinical application, which limits its further promotion: insufficient antibacterial performance: the existing dressing has weak inhibitory ability to common pathogenic bacteria (such as gram-positive bacteria Staphylococcus aureus and gram-negative bacteria Escherichia coli), and cannot effectively block the bacterial propagation induced by wound exudate (containing a large amount of nutrients), which is easy to cause repeated wound infection, thereby prolonging the healing period and increasing the risk of complications; limited water absorption capacity: skin trauma (especially moderate and severe trauma such as pressure sores and burns) is often accompanied by a large amount of tissue fluid and a small amount of blood exudation, and the water absorption capacity and liquid absorption rate of the existing dressing are difficult to meet the clinical needs, and the excess exudate retained on the surface of the wound not only provides a breeding ground for bacteria, but also may cause the dressing and the skin at the wound edge to be soaked, and the tissue damage is aggravated; wound adhesion problem: due to the poor interface compatibility regulation of the hydrogel and the wound tissue, the dressing is easy to adhere to the newly generated epithelial tissue or granulation tissue after long-term coverage, and external force is needed to peel off when replacing, which is easy to cause tearing of the newly generated tissue and cause secondary injury, and at the same time increase the pain of the patient during dressing change.

[0005] Therefore, it is a key requirement to develop a natural polysaccharide antibacterial hydrogel dressing with high efficient antibacterial performance, excellent water absorption capacity and low wound adhesion, which becomes a key requirement to solve the current clinical wound care pain points and improve the treatment effect of trauma. SUMMARY

[0006] Based on this, the purpose of the present application is to provide a natural polysaccharide copper-based antibacterial hydrogel, a preparation method and an application, which solves the problems of poor antibacterial performance, poor water absorption and easy adhesion to the wound surface of the existing natural polysaccharide antibacterial hydrogel dressing.

[0007] In order to solve the above technical problems, one of the purposes of the present application is to provide a natural polysaccharide copper-based antibacterial hydrogel, which is prepared from the following raw materials by weight: sesbania gum and its derivatives: 4-9 parts; activator: 6-9 parts; cross-linking active filler: 0.06-0.12 parts; cross-linking agent: 1-5 parts; deionized water: 65-85 parts; antibacterial agent: 0.4-1.1 parts.

[0008] Preferably, the sesbania gum derivative is one or more of oxidized sesbania gum, aminated sesbania gum, carboxylated sesbania gum, carboxymethyl sesbania gum, hydroxyl sesbania gum or epoxidized sesbania gum.

[0009] Preferably, the activator is sodium hydroxide or potassium hydroxide.

[0010] Preferably, the cross-linking active filler is tetramethylammonium bromide or triethylbenzylammonium chloride.

[0011] Preferably, the cross-linking agent is epichlorohydrin, 1-bromo-2,3-epoxypropane or a-halogenated epoxy acid ester.

[0012] Preferably, the antibacterial agent is copper chloride, copper sulfate, copper nitrate or copper acetate.

[0013] Based on the same inventive concept, the application also provides a preparation method of the natural polysaccharide copper-based antibacterial hydrogel, comprising the following steps: S1: Dissolve the sesbania gum and its derivatives in water, add an activator for sufficient activation, then add a crosslinking agent and a crosslinking active filler, stir uniformly to form a natural polysaccharide antibacterial hydrogel; S2: Add the natural polysaccharide antibacterial hydrogel into an antibacterial agent, oscillate and adsorb, wash with deionized water to obtain the natural polysaccharide copper-based antibacterial hydrogel.

[0014] Preferably, the activation time in S1 is 8 h, and the crosslinking time is 4 h; the adsorption time in S2 is 2 h.

[0015] The application also provides an application of the natural polysaccharide copper-based antibacterial hydrogel, and the natural polysaccharide copper-based antibacterial hydrogel is used for wound dressing.

[0016] The one or more technical solutions of the application have the following technical effects: 1) Good biocompatibility: The sesbania gum and its derivatives and the crosslinking agent used have high biological activity and biodegradability, can create a good microenvironment for rapid wound repair, and can self-degrade after the active antibacterial component is released to avoid causing additional damage to the wound; and the cell survival rate is more than 90% (natural polysaccharide copper-based antibacterial hydrogel) or more than 95% (natural polysaccharide antibacterial hydrogel) after the dressing is co-incubated with mouse embryonic fibroblasts, which has excellent biocompatibility and can be safely used on the surface of a living body; 2) Strong water absorption, water retention and bacteria growth prevention effects: The dressing has a three-dimensional polymer network structure with high water content, has excellent water absorption and water retention performance, can effectively absorb the tissue fluid exuded from the wound, reduces the bacteria growth conditions caused by liquid retention, indirectly assists in reducing the risk of wound infection, and maintains a moist environment for the wound, which meets the humidity requirement of wound healing; 3) High-efficiency and long-acting antibacterial performance: The copper salt antibacterial agent is introduced into the gel matrix by oscillation adsorption, and the copper ions can be continuously released during use to achieve long-acting antibacterial effect; has a significant inhibitory effect on gram-positive bacteria (Staphylococcus aureus) and gram-negative bacteria (Escherichia coli). S. aureus E. coli The inhibitory rates are 90.8% and 89% respectively within a short time (10 min), and the inhibitory rates are as high as 99.8% and 97.8% respectively when the dosage is increased to 50 mg, which can effectively avoid the infection problems such as inflammation and abscess during the wound healing process and reduce the risk of complications. BRIEF DESCRIPTION OF DRAWINGS​

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the embodiments will be briefly introduced.

[0018] Figure 1 、 Figure 1 (a) SEM image of the natural polysaccharide antibacterial hydrogel prepared in Example 1; Figure 1 (b) SEM image of the natural polysaccharide copper-based antibacterial hydrogel prepared in Example 1; Figure 2 , infrared spectrum test image of the mesquite gum, the natural polysaccharide antibacterial hydrogel and the natural polysaccharide copper-based antibacterial hydrogel in Example 1; Figure 3 , adsorption and release graph of the natural polysaccharide antibacterial hydrogel to copper ions under different initial concentrations of copper ions; Figure 4 , adsorption graph of the natural polysaccharide antibacterial hydrogel to copper ions under different copper ion adsorption times; Figure 5 、 Figure 5 (a) water absorption rate effect graph of the natural polysaccharide antibacterial hydrogel and the natural polysaccharide copper-based antibacterial hydrogel under different time conditions; Figure 5 (b) water retention rate effect graph of the natural polysaccharide antibacterial hydrogel and the natural polysaccharide copper-based antibacterial hydrogel under different time conditions; Figure 6 , antibacterial effect graph of the natural polysaccharide copper-based antibacterial hydrogel to gram-positive bacteria (Staphylococcus aureus) S. aureus ) and gram-negative bacteria (Escherichia coli) E. coli ) under different dosing conditions; Figure 7 , antibacterial effect graph of the natural polysaccharide copper-based antibacterial hydrogel to gram-positive bacteria (Staphylococcus aureus) S. aureus ) and gram-negative bacteria (Escherichia coli) E. coli ) under different time conditions; Figure 8 , cell viability graph of the natural polysaccharide antibacterial hydrogel and the natural polysaccharide copper-based antibacterial hydrogel after acting on cells; Figure 9 , comparison graph of wound healing effects of mice in different treatment groups. DETAILED DESCRIPTION

[0019] The natural polysaccharide copper-based antibacterial hydrogel is prepared from the following raw materials by weight: mesquite gum and its derivatives: 4-9 parts; activator: 6-9 parts; cross-linking active filler: 0.06-0.12 parts; cross-linking agent: 1-5 parts; deionized water: 65-85 parts; antibacterial agent: 0.4-1.1 parts.

[0020] The sesbania gum derivative is one or more of oxidized sesbania gum, aminated sesbania gum, carboxylated sesbania gum, carboxymethyl sesbania gum, hydroxyl sesbania gum or epoxidized sesbania gum.

[0021] The activator is sodium hydroxide, potassium hydroxide or other inorganic salt capable of providing an alkaline environment.

[0022] The cross-linking active filler is tetramethylammonium bromide, triethylbenzylammonium chloride or other quaternary ammonium salt, quaternary phosphonium salt or polyether compound capable of promoting exchange between the organic phase and the aqueous phase.

[0023] The cross-linking agent is epichlorohydrin, 1-bromo-2,3-epoxypropane, a-halogenated epoxy acid ester or other halogenated epoxy compound.

[0024] The antibacterial agent is copper chloride, copper sulfate, copper nitrate, copper acetate or other copper salt and derivative thereof.

[0025] The application further provides a preparation method of the natural polysaccharide copper-based antibacterial hydrogel, comprising the following steps: S1: dissolving the sesbania gum and derivative thereof in water, then adding an activator to activate sufficiently, adding a cross-linking agent and a cross-linking active filler, and stirring uniformly to form a natural polysaccharide antibacterial hydrogel; S2: adding the natural polysaccharide antibacterial hydrogel into an antibacterial agent, oscillating and adsorbing to obtain a natural polysaccharide copper-based antibacterial hydrogel.

[0026] The activation time in S1 is 8 h, and the cross-linking time is 4 h; the adsorption time in S2 is 2 h.

[0027] The application further provides an application of the natural polysaccharide copper-based antibacterial hydrogel, and the natural polysaccharide copper-based antibacterial hydrogel is used for wound dressing.

[0028] The technical solutions of the application will be described clearly and completely in combination with the drawings of the application. All other embodiments obtained by those skilled in the art without creative labor on the basis of the embodiments in the application belong to the protection scope of the application.

[0029] In the entire specification, unless otherwise specifically stated, the terms used herein are understood as having the meanings as generally used in the art. Therefore, unless otherwise defined, all the technical and scientific terms used herein have the same meanings as generally understood by those skilled in the art to which the application belongs. If there is a conflict, the specification is preferred.

[0030] Example 1 A preparation method of a natural polysaccharide copper-based antibacterial hydrogel, comprising the following steps: S1: 1 g of the jute gum was dissolved in 20 mL of deionized water, 1.8 g of sodium hydroxide was added, and activated for 8 h. After stirring at room temperature for 6 h, 1.0 ml of epichlorohydrin and 1.0 mL of 1.5% tetramethylammonium bromide deionized water solution were added, and stirred for 4 h to form a natural polysaccharide antibacterial hydrogel; S2: 0.2 g of the natural polysaccharide antibacterial hydrogel was added to 200 ml of 0.2 g / L copper chloride antibacterial agent, and shaken for 2 h. After washing with deionized water three times, a natural polysaccharide copper-based antibacterial hydrogel was obtained.

[0031] Example 2 A method for preparing a natural polysaccharide copper-based antibacterial hydrogel, comprising the following steps: S1: 1 g of the jute gum was dissolved in 20 mL of deionized water, 1.8 g of sodium hydroxide was added, and activated for 8 h. After stirring at room temperature for 6 h, 1.0 ml of epichlorohydrin and 1.0 mL of 1.5% tetramethylammonium bromide deionized water solution were added, and stirred for 4 h to form a natural polysaccharide antibacterial hydrogel; S2: 0.2 g of the natural polysaccharide antibacterial hydrogel was added to 200 ml of 0.2 g / L copper chloride antibacterial agent, and shaken for 2 h. After washing with deionized water three times, a natural polysaccharide copper-based antibacterial hydrogel was obtained.

[0032] Example 3 A method for preparing a natural polysaccharide copper-based antibacterial hydrogel, comprising the following steps: S1: 1 g of the jute gum was dissolved in 20 mL of deionized water, 1.8 g of sodium hydroxide was added, and activated for 8 h. After stirring at room temperature for 6 h, 1.0 ml of epichlorohydrin and 1.0 mL of 1.5% tetramethylammonium bromide deionized water solution were added, and stirred for 4 h to form a natural polysaccharide antibacterial hydrogel; S2: 0.2 g of the natural polysaccharide antibacterial hydrogel was added to 200 ml of 0.2 g / L copper chloride antibacterial agent, and shaken for 2 h. After washing with deionized water three times, a natural polysaccharide copper-based antibacterial hydrogel was obtained.

[0033] Example 4 A method for preparing a natural polysaccharide copper-based antibacterial hydrogel, comprising the following steps: S1: 1 g of the jute gum was dissolved in 20 mL of deionized water, 1.8 g of sodium hydroxide was added, and activated for 8 h. After stirring at room temperature for 6 h, 1.0 ml of epichlorohydrin and 1.0 mL of 1.5% tetramethylammonium bromide deionized water solution were added, and stirred for 4 h to form a natural polysaccharide antibacterial hydrogel; S2: 0.2 g of natural polysaccharide antibacterial hydrogel was added into 100 ml of 0.4 g / L copper nitrate solution, shaken for 2 h, washed with deionized water for three times, and then a natural polysaccharide copper-based antibacterial hydrogel was obtained.

[0034] Comparative Example 1 A preparation method of a natural polysaccharide antibacterial hydrogel, comprising the following steps: S1: 1 g of sesbania gum was dissolved in 20 mL of ultrapure water, then 1.8 g of sodium hydroxide was added, stirred at room temperature for 6 h, and then a hydrogel was obtained.

[0035] S2: 1.0 ml of epichlorohydrin and 1 mL of tetramethylammonium bromide solution were added to the hydrogel of S1 and stirred for 4 h, and then unreacted components in the hydrogel were removed, and a natural polysaccharide antibacterial hydrogel was obtained.

[0036] Test Example 1: The natural polysaccharide antibacterial hydrogel and the natural polysaccharide copper-based antibacterial hydrogel prepared in Example 1 were characterized by SEM, as shown in Figure 1 (a), the natural polysaccharide antibacterial hydrogel as a whole showed a rough and dense structure, and the cross-linking degree of the gel was low. As shown in Figure 1 (b), the natural polysaccharide copper-based antibacterial hydrogel after adsorbing copper ions showed a transition from dense to porous, and the internal pore structure of the adsorbed copper ions was relatively smooth, and the cross-linking degree was obviously improved. The rich pore structure in the hydrogel may be the complexation between the natural polysaccharide antibacterial hydrogel and the copper ions, and the copper ions act as cross-linking points between the natural polysaccharide antibacterial hydrogel.

[0037] Test Example 2: Infrared spectrum test The sesbania gum, the natural polysaccharide antibacterial hydrogel and the natural polysaccharide copper-based antibacterial hydrogel in Example 1 were tested by infrared spectrum using a Thermo Scientific Nicolet iS5 type Fourier transform infrared spectrometer, as shown in Figure 2 , in the infrared spectrum of the sesbania gum, the characteristic absorption peak of the hydroxyl group appeared at 3100-3500 cm -1 , and the characteristic absorption peak of the ether bond C-O-C appeared at 1015-1150 cm -1 , in the infrared spectrum of the natural polysaccharide antibacterial hydrogel, the characteristic absorption peak of the hydroxyl group appeared at 3100-3500 cm -1 , and the characteristic absorption peak of the ether bond C-O-C appeared at 1015-1150 cm -1 , and the absorption peaks of the ether bond C-O-C and the hydroxyl group were enhanced, the natural polysaccharide polymer chain length was increased, and the cross-linking degree was obviously improved, indicating that the natural polysaccharide antibacterial hydrogel was successfully prepared. In the infrared spectrum of the natural polysaccharide copper-based antibacterial hydrogel, the characteristic absorption peak of the ether bond C-O-C appeared at 1015-1150 cm-1 characteristic absorption peak of ether C-O-C appeared at 3100-3500 cm -1 characteristic absorption peak of hydroxyl group appeared at 3200-3600 cm, and the absorption peaks of ether C-O-C and hydroxyl group were weaker than those of natural polysaccharide antibacterial hydrogel, and copper ions replaced part of hydrogen atoms in the hydroxyl groups of natural polysaccharide antibacterial hydrogel, indicating that the natural polysaccharide copper-based antibacterial hydrogel was successfully prepared.

[0038] Test Example 3: Adsorption performance test Preparation of copper ion standard solution: accurately weigh the copper salt, and prepare 1 g / L of copper ion standard solution for standby.

[0039] (1) Concentration gradient 20 mg of natural polysaccharide antibacterial hydrogel was added to 20 ml of copper ion solution with different concentrations (50, 100, 200, 300, 400, 500, 600, 700, 800, 900, 1000 mg / L) and shaken for 2 h. The supernatant after adsorption was taken out, diluted, and the copper ion concentration was determined by flame atomic absorption. The natural polysaccharide copper-based antibacterial hydrogel after adsorption was added to 20 ml of distilled water and shaken for 2 h, and the released copper ion concentration in the supernatant was determined.

[0040] As shown in Figure 3 , with the increase of copper ion concentration, the adsorption capacity of natural polysaccharide antibacterial hydrogel also increased, and when the copper ion concentration reached 900 mg / L, the maximum adsorption capacity was 457.2 mg / g, and the maximum release amount of copper ion in water under this condition was 12.6 mg / g. When the copper ion concentration was 1000 mg / L, the release amount of copper ion of natural polysaccharide antibacterial hydrogel reached 12.66 mg / g.

[0041] (2) Time gradient 20 mg of natural polysaccharide antibacterial hydrogel was added to 20 ml of copper ion solution with a concentration of 900 mg / L, and shaken for different times (20, 40, 60, 80, 100, 120, 140, 160 min). The supernatant after adsorption was taken out, diluted, and the copper ion concentration was determined by flame atomic absorption.

[0042] As shown in Figure 4 , with the increase of adsorption time, the adsorption capacity of natural polysaccharide antibacterial hydrogel also increased, and when the shaking time reached 140 min, the adsorption reached the maximum value.

[0043] Test Example 4: Water absorption and water retention test Wound dressings also need excellent absorbency and moisture retention capabilities, absorbing wound exudate while maintaining moisture around the wound to prevent excessive dryness or fluid accumulation. Therefore, we tested the water absorption and retention properties of natural polysaccharide antibacterial hydrogels and natural polysaccharide copper-based antibacterial hydrogels. Figure 5 As shown in (a)-(b), the water absorption rate of natural polysaccharide antibacterial hydrogel and natural polysaccharide copper-based antibacterial hydrogel increases with the extension of soaking time in water. When the soaking time is extended to 200 min, the water absorption rates of natural polysaccharide antibacterial hydrogel and natural polysaccharide copper-based antibacterial hydrogel reach 4567% and 3158%, respectively. The water retention rates of natural polysaccharide antibacterial hydrogel and natural polysaccharide copper-based antibacterial hydrogel are 15% and 19% after 24 h.

[0044] Test Example 5: In vitro antibacterial test Use Gram-positive bacteria ( S. aureus ) and Gram-negative bacteria ( E. coli Two bacterial models were used. Different masses (10, 20, 30, 40, 50 mg) of natural polysaccharide copper-based antibacterial hydrogel and bacteria (1 × 10⁻⁶ mg) were weighed as shown in Example 1. 6 CFU / mL The hydrogels were co-cultured under natural light (2, 4, 6, 8, 10 min), and the antibacterial properties of the hydrogels were measured using the plate count method. The antibacterial properties of the hydrogels were compared under natural light conditions. S. aureus and E. coli The antibacterial properties of the hydrogel were evaluated by assessing bacterial activity and proliferation.

[0045] like Figure 6 As shown, the effect of increasing the dosage from 10 mg to 50 mg on the natural polysaccharide copper-based antibacterial hydrogel is significant. S. aureus The inhibitory effect increased from 59.4% to 99.8%, and the inhibitory effect on... E. coli The antibacterial effect increased from 31.7% to 97.8%. When the dosage was below 30 mg, the natural polysaccharide copper-based antibacterial hydrogel showed improved antibacterial activity. S. aureus The inhibitory effect is stronger than E. coli After increasing the dosage, the natural polysaccharide copper-based antibacterial hydrogel has an effect on... E. coli and S. aureus The antibacterial effects are similar.

[0046] like Figure 7 As shown, 30 mg of the natural polysaccharide copper-based antibacterial hydrogel from Example 1 was weighed and co-cultured with bacteria under natural light for 2-10 min. The natural polysaccharide copper-based antibacterial hydrogel... S. aureus The inhibitory effect increased from 50.9% to 90.8%, and the antibacterial effect against *E. coli* increased from 24.3% to 89%. Under short-term contact conditions, the natural polysaccharide copper-based antibacterial hydrogel showed improved efficacy against...S. aureus The inhibitory effect is stronger than E. coli Extending contact time, natural polysaccharide copper-based antibacterial hydrogel has the effect of... E. coli and S. aureus The antibacterial effects are similar.

[0047] Test Example 6: Cytotoxicity Test Biocompatibility testing: The toxicity of the hydrogel to non-bacterial cells was determined using the CCK-8 assay. Specifically, 100 μL of mouse embryonic fibroblasts (NIH-3T3) containing 5000 cells were seeded into 96-well plates and incubated at 37°C with 5% CO2. Once cell aggregation reached 70%, the medium was replaced with 100 μL of fresh medium containing hydrogel extract, with a control group (without hydrogel). After 24 h of incubation, 10 μL of CCK-8 solution was added to each well, and the plates were returned to the incubator for 2 hours. The OD value of the medium was measured using a microplate reader. 450 The value is used to assess cell viability.

[0048] like Figure 8 As shown, after incubating the natural polysaccharide antibacterial hydrogel prepared in Comparative Example 1 with NIH-3T3 cells for 24 h, the cell survival rate remained above 95%. After co-incubating the extract of the natural polysaccharide copper-based antibacterial hydrogel prepared in Example 1 with cells, the cell survival rate was consistently around 90%, indicating that the natural polysaccharide copper-based antibacterial hydrogel has the advantage of low cytotoxicity and can be used for antibacterial treatment on the surface of organisms.

[0049] Test Example 7: Wound Healing Test The effect of natural polysaccharide copper-based antibacterial hydrogel on wound healing in bacterial infections was investigated using a mouse wound healing experiment. Figure 9 As shown in the figure, digital images depict the wound healing status of the blank control group, the group treated with natural polysaccharide antibacterial hydrogel, and the group treated with natural polysaccharide copper-based antibacterial hydrogel from day 0 to day 7. The blank control group received no treatment, and its wound repair relied entirely on the mice's own self-healing ability, resulting in an extremely slow healing process. Compared to the blank control group, the natural polysaccharide antibacterial hydrogel did not significantly promote wound healing: from day 1 to day 5, the wound area in this group was not significantly different from the blank control group; only on day 7 did the healing effect slightly surpass that of the blank control group. The natural polysaccharide copper-based antibacterial hydrogel exhibited the fastest wound healing speed. To more intuitively observe the effect of hydrogel treatment on infected wounds, we measured the change in wound diameter. Figure 9 As shown, by day 7, the wound diameter in the blank control group decreased by 1.43 mm, the natural polysaccharide antibacterial hydrogel group decreased by 1.31 mm, and the natural polysaccharide antibacterial hydrogel group decreased by 2.37 mm.

Claims

1. A natural polysaccharide copper-based antibacterial hydrogel, characterized in that, The natural polysaccharide copper-based antibacterial hydrogel is prepared from the following raw materials in parts by weight: guar gum and its derivatives: 4-9 parts; activator: 6-9 parts; crosslinking active filler: 0.06-0.12 parts; crosslinking agent: 1-5 parts; Deionized water: 65-85 parts; Antibacterial agent: 0.4-1.1 parts.

2. The natural polysaccharide copper-based antibacterial hydrogel according to claim 1, characterized in that: The guar gum derivative is one or more of the following: oxidized guar gum, aminoized guar gum, carboxylated guar gum, carboxymethyl guar gum, hydroxylated guar gum, or epoxidized guar gum.

3. The natural polysaccharide copper-based antibacterial hydrogel according to claim 1, characterized in that: The activator is sodium hydroxide or potassium hydroxide.

4. The natural polysaccharide copper-based antibacterial hydrogel according to claim 1, characterized in that: The crosslinking active filler is tetramethylammonium bromide or triethylbenzylammonium chloride.

5. The natural polysaccharide copper-based antibacterial hydrogel according to claim 1, characterized in that: The crosslinking agent is epichlorohydrin, 1-bromo-2,3-epoxypropane, or α-haloepoxy ester.

6. The natural polysaccharide copper-based antibacterial hydrogel according to claim 1, characterized in that: The antibacterial agent is copper chloride, copper sulfate, copper nitrate, or copper acetate.

7. A method for preparing the natural polysaccharide copper-based antibacterial hydrogel as described in any one of claims 1-6, characterized in that, Includes the following steps: S1: Dissolve guar gum and its derivatives in water, add an activator to fully activate them, then add a crosslinking agent and a crosslinking active filler, stir evenly to form a natural polysaccharide antibacterial hydrogel; S2: Add the natural polysaccharide antibacterial hydrogel to the antibacterial agent, shake to adsorb, and wash with deionized water to obtain the natural polysaccharide copper-based antibacterial hydrogel.

8. The method for preparing the natural polysaccharide copper-based antibacterial hydrogel according to claim 7, characterized in that: The activation time in S1 is 8 h, and the crosslinking time is 4 h; the adsorption time in S2 is 2 h.

9. The application of a natural polysaccharide copper-based antibacterial hydrogel as described in any one of claims 1-6, characterized in that: The natural polysaccharide copper-based antibacterial hydrogel is used as a wound dressing.

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