Preparation method of composite antibacterial hydrogel dressing

Abstract

The invention provides a preparation method of a composite antibacterial hydrogel dressing, and relates to the field of medical materials.The preparation method comprises the steps that a hydrogel matrix is prepared; deionized water is added into the CuS nano-particles, a dispersing agent is added, and CuS dispersion liquid is prepared through ultrasonic dispersion; the method comprises the following steps: inoculating chlorella in a logarithmic phase into a culture medium for culturing, centrifugally collecting chlorella mud, and resuspending to prepare chlorella bacterial suspension with target concentration. Immersing the hydrogel matrix into a CuS dispersion liquid for ultrasonic treatment to load CuS nanoparticles, washing and airing; and immersing the CuS into a chlorella suspension, incubating on a shaking table to form a chlorella cell layer on the surface of the CuS, and washing to remove free chlorella to obtain an intermediate product. The step of loading the CuS and the chlorella is repeated until the loading capacity of the CuS and the chlorella reaches the standard, finally, the hydrogel material obtained after loading is completed is placed in a sterile culture medium to be subjected to standing culture, and the composite antibacterial hydrogel dressing is prepared. CuS, chlorella and hydrogel are compounded to construct a triple synergistic system, and the problems of infection, hypoxia and inflammation are synchronously solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of medical materials, in particular to a preparation method of a composite antibacterial hydrogel dressing. BACKGROUND

[0002] Wound healing is a complex biological process, and skin tissue damage, hypoxia and microbial invasion can lead to serious wound infection and even cause patient death. The moist environment maintained by simple hydrogel dressings can promote bacterial growth, and is not conducive to oxygen entry, so the development of new drug dressings loaded with efficient antibacterial agents and capable of producing oxygen is a difficult problem to be solved at present.

[0003] Microalgae and photothermal material composite hydrogel as a new emerging biological drug material has shown great potential in the field of wound repair. Microalgae as a natural source of bioactive compounds, its metabolites include polysaccharides, proteins, lipids, pigments, antioxidants and other components, which promote wound healing through different mechanisms. The polysaccharides and astaxanthin secreted by Chlorella vulgaris can scavenge reactive oxygen species (ROS), inhibit inflammation, and promote blood vessel regeneration, while the heat effect of photothermal materials under laser irradiation can promote blood circulation and further improve tissue oxygen supply; refer to the following papers: 1. Yan Zhenzhen, Wang Yuxiang, Zhang Tinglin, et al. Performance of silver nanoparticle-loaded Chlorella vulgaris gelatin / polyethylene glycol hydrogel and its effect on full-thickness skin defect infection wound healing in mice [J]. Chinese Journal of Burns and Wound Repair, 2024, 40(1): 33-42; 2. Wang Yuxiang. Experimental study on platinum in situ hybrid Chlorella vulgaris multifunctional hydrogel for promoting wound repair [D]. 2025.

[0004] In the prior art, copper sulfide (CuS) nanocomposite hydrogel dressing has unique advantages: first, CuS nanoparticles themselves have near-infrared light-responsive photothermal-photodynamic properties, which can produce excellent bactericidal effect; second, the copper ions released by CuS nanoparticles can effectively promote angiogenesis and endothelial cell proliferation, thereby promoting wound healing.

[0005] Existing technologies for preparing antibacterial materials (such as antibacterial dressings) by combining hydrogels, microalgae and copper sulfide materials, such as CN120000623A Multifunctional microneedle patch and its preparation method and application, have the following problems: Simply physically mixing microalgae exosomes and copper sulfide nanoparticles into hydrogels lacks dynamic control of the loading process, which cannot guarantee uniform penetration of nanoparticles in the pores of the hydrogel, nor can it precisely control the loading amount of each active ingredient, ultimately leading to aggregation of components, uneven loading, and difficulty in exerting the synergistic effect of copper sulfide and microalgae exosomes. SUMMARY

[0006] The application provides a preparation method of a composite antibacterial hydrogel dressing to solve the technical problems in the background art.

[0007] To solve the above technical problems, the application discloses a preparation method of a composite antibacterial hydrogel dressing, comprising the following steps: Step 1: preparing a hydrogel matrix; Step 2: weighing CuS nanoparticles, adding deionized water and a dispersing agent, and performing ultrasonic dispersion to prepare a CuS dispersion liquid; Step 3: inoculating Chlorella in a logarithmic growth phase into a culture medium, culturing to a preset algal cell concentration, collecting algal sludge by centrifugation, and resuspending the algal sludge with sterile deionized water to prepare a Chlorella bacterial suspension with a target concentration; Step 4: immersing the hydrogel matrix prepared in step 1 in the CuS dispersion liquid, performing ultrasonic treatment, loading CuS nanoparticles on the surface and pores of the hydrogel, washing the surface of the hydrogel with deionized water to remove CuS that is not adsorbed, and air-drying at room temperature; Step 5: immersing the CuS-loaded hydrogel matrix in the Chlorella bacterial suspension, incubating on a shaking table, forming an algal cell layer on the surface of the CuS layer, washing the CuS-loaded hydrogel matrix with sterile deionized water to remove free Chlorella that is not combined, and obtaining an intermediate product loaded with CuS and Chlorella; Step 6: repeating the loading process of steps 4 and 5, sampling and detecting the loading amount of CuS and the loading amount of Chlorella in the hydrogel material after each round of loading, adjusting the concentration of the CuS dispersion liquid in the next round of loading if the loading amount of CuS does not meet the standard, adjusting the concentration of the Chlorella bacterial suspension in the next round of loading if the loading amount of Chlorella does not meet the standard, and continuing until the loading amounts of CuS and Chlorella both meet the target requirements; Finally, placing the completed CuS-loaded hydrogel material in a sterile culture medium for static culture to prepare the composite antibacterial hydrogel dressing.

[0008] Preferably, in step 1, the dispersing agent is any one of sodium dodecyl benzene sulfonate, polyvinylpyrrolidone or Tween-80, and the mass fraction of the dispersing agent in the CuS dispersion liquid is 0.05% to 0.2%. The concentration of the prepared CuS dispersion liquid is 50 to 200 μg / mL.

[0009] Preferably, the ultrasonic power in step 2 is 200 to 400 W, the ultrasonic power in step 4 is 100 to 200 W, the rotation speed of the shaking table during the incubation process is 50 to 80 r / min, and the ultrasonic power in step 6 is 80 to 120 W.

[0010] Preferably, the preset algal cell concentration is 1×10 7 to 1×10 8 / mL, and the target concentration is 5×10 6 to 5×10 7Chlorella vulgaris concentration target requirement is 5 x 10 5 ~ 5 x 10 6 / cm².

[0011] Preferably, in step 3, Chlorella in the logarithmic growth phase is inoculated into the culture medium and cultured to a preset algal cell concentration, specifically: Chlorella in the logarithmic growth phase is inoculated into BG11 culture medium and cultured under the conditions of light intensity 2000-3000lx, light-dark cycle 12h:12h, and temperature 25-28℃. In step 6, the loaded hydrogel material is placed in sterile BG11 culture medium and incubated at 25-28℃ under 1000-1500lx light for 2-4h to obtain the composite antibacterial hydrogel dressing.

[0012] Preferably, step 1 comprises: Step 11: The hydrogel base material monomer, crosslinking agent, and initiator are prepared according to the preparation ratio, added to deionized water, ultrasonically dissolved, and uniformly stirred to obtain a clear hydrogel precursor solution with a hydrogel base material monomer concentration of 100-300g / L; the mass ratio of the hydrogel base material monomer, crosslinking agent, and initiator is 1:0.005-0.05:0.001-0.02; Step 12: Dopamine hydrochloride is added to the hydrogel precursor solution, the pH value of the system is adjusted to 8.0-8.5, and the system is stirred and reacted at 25-35℃ for 2-4h to allow dopamine to polymerize in situ and disperse uniformly in the hydrogel precursor solution; by controlling the amount of dopamine hydrochloride added, the mass fraction of PDA in the hydrogel matrix is 0.5%-2%; Step 13: The precursor solution doped with PDA is injected into a mold, and the mold is placed at 30-60℃ for 1-3h for crosslinking. After demolding, a crude hydrogel matrix is obtained. The crude hydrogel matrix is then soaked in deionized water for 24-48h, and the deionized water is replaced during the soaking to remove unreacted monomers, crosslinking agents, and byproducts, and finally the hydrogel matrix is obtained.

[0013] Preferably, in the experimental stage, step 4 of the target experimental group is selected for benchmarking experiments. During the benchmarking experiments, the ultrasonic time, CuS dispersion liquid temperature, CuS dispersion liquid viscosity, and CuS dispersion liquid conductivity are detected. According to the detection results of the benchmarking experiments, an ultrasonic time-experimental CuS dispersion liquid conductivity curve and an ultrasonic time-experimental CuS dispersion liquid temperature curve are constructed, and the ultrasonic time-experimental CuS dispersion liquid conductivity curve and the ultrasonic time-experimental CuS dispersion liquid temperature curve are divided into multiple first sub-curves and second sub-curves according to the loading rounds; each first sub-curve and each second sub-curve corresponds to a loading round; and build the CuS dispersion liquid viscosity sequence corresponding to each loading round according to the order of detection time; and set up a gradient experiment to build the conductivity ratio range-viscosity ratio range-target ultrasonic power of each round of loading relationship.

[0014] Preferably, the step 4 comprises: Step 41: Obtain the baseline ultrasonic power corresponding to each round of loading corresponding to the baseline determination experiment; Step 42: immerse the hydrogel matrix prepared in step 1 in the CuS dispersion liquid, and perform ultrasonic treatment with the baseline ultrasonic power corresponding to the first round of loading; and detect the conductivity of the CuS dispersion liquid multiple times within a first time period; determine the actual average conductivity change rate of the CuS dispersion liquid, and determine the average conductivity change rate deviation, and when the average conductivity change rate deviation meets the requirements, continue to perform ultrasonic treatment with the baseline ultrasonic power corresponding to each round; the first time period is a preset proportion of the total ultrasonic time of the first round of loading; Step 43: When the average conductivity change rate deviation does not meet the requirements, determine the predicted conductivity range of the first round of loading and the predicted viscosity range of the CuS dispersion liquid based on the detection results of step 42 and in combination with the CuS dispersion liquid viscosity sequence and the first sub-curve, and determine the actual conductivity difference and the actual viscosity difference based on the predicted conductivity range of the first round of loading and the predicted viscosity range of the CuS dispersion liquid, and determine the actual conductivity ratio and the actual viscosity ratio in combination with the actual conductivity difference and the actual viscosity difference; Based on the actual conductivity ratio and the actual viscosity ratio, the preset conductivity ratio range-viscosity ratio range-target ultrasonic power of each round of loading relationship determines the current target ultrasonic power of each round of loading; continue to perform ultrasonic treatment with the current target ultrasonic power of each round.

[0015] Preferably, the baseline determination experiment process further comprises: Divide each second sub-curve for slope analysis, divide each second sub-curve into different temperature characteristic segments, and bind a preset temperature node value and a corresponding ultrasonic time threshold value for each temperature characteristic segment; Step 43 further comprises: during the ultrasonic treatment with the current target ultrasonic power of each round, multiple times of detecting the CuS dispersion liquid temperature corresponding to each round of loading, when the CuS dispersion liquid temperature enters the corresponding temperature characteristic segment, triggering the ultrasonic time control rule of this round: If the temperature reaches the preset node value corresponding to the characteristic segment, strictly limit the cumulative time length of this round of ultrasonic to be no more than the time threshold value bound by the characteristic segment; if the temperature exceeds the highest characteristic segment node value of the second sub-curve of this round, immediately terminate the ultrasonic treatment of this round.

[0016] The technical solutions of the present application are described in further detail below with reference to the accompanying drawings and examples.

[0017] In comparison with the prior art, the present application has the following beneficial effects: By combining CuS (photothermal antibacterial), Chlorella (oxygen-producing anti-inflammatory), and hydrogel (adhesion promoting healing), a triple synergistic system is constructed to simultaneously address infection, hypoxia, and inflammation.

[0018] Through PDA-mediated interfacial interaction (phenolic hydroxyl groups bind with CuS and Chlorella surface groups), the dispersion of CuS and the stability of Chlorella are optimized, avoiding the inhibition of photothermal activity on microalgae.

[0019] The synergistic mechanism of microalgae and photothermal materials in hydrogel is the key to the therapeutic effect of this composite system. This synergistic effect mainly manifests in the following aspects: First, functional complementation. Microalgae continuously produce oxygen through photosynthesis, improving the hypoxic microenvironment at the wound site, while the thermal effect of photothermal materials under laser irradiation can promote blood circulation, further improving tissue oxygen supply. Second, time sequence synergy. By adjusting the light intensity and irradiation time, the time sequence control of microalgae and photothermal material functions can be achieved. Third, spatial synergy. In a double or multi-layer hydrogel structure, microalgae and photothermal materials can function at different levels. Fourth, metabolic product synergy. Microalgae not only produce oxygen but also secrete various bioactive substances such as polysaccharides, proteins, antioxidants, etc. during photosynthesis, which synergistically act with the thermal effect of photothermal materials to promote wound healing. Research has found that Chlorella extract contains various bioactive compounds with antioxidant, anti-inflammatory, and antibacterial properties. Finally, immune regulation synergy. Microalgae and photothermal materials both have immune regulation functions, and their synergistic action can more effectively regulate the immune microenvironment of the wound (Dai Yunli. Synthesis of nano cerium oxide based on green Chlorella and its antibacterial application in constructing antibacterial hydrogel coating for urinary catheters [D]. Qingdao: Qingdao University, 2024).

[0020] The present application breaks through the uneven load problem caused by physical mixing in the prior art through a closed-loop mechanism of "multiple rounds of loading-detection-calibration". It can precisely regulate the loading amount of CuS nanoparticles and Chlorella, ensuring uniform penetration of nanoparticles in the pores of the hydrogel, with CuS loading stabilized at 5-20 μg / cm² and Chlorella loading stabilized at 5×10 5 ~ 5×10 6 cm², effectively avoiding component aggregation.

[0021] The application forms an ordered functional layer of CuS nanoparticles and Chlorella in the hydrogel through a step-by-step loading process instead of simple physical mixing. This structure ensures that the photothermal sterilization effect of CuS and the oxygen production and anti-inflammatory effect of Chlorella can work together, significantly improving the removal ability of drug-resistant bacteria and biofilms, and improving the wound microenvironment and accelerating the healing process. BRIEF DESCRIPTION OF DRAWINGS

[0022] The accompanying drawings are included to provide a further understanding of the application, and are incorporated in and constitute a part of the specification, illustrate embodiments of the application, and together with the description serve to explain the application, and are not intended to limit the application in any way. In the drawings: Figure 1 It is a flowchart of the application. DETAILED DESCRIPTION

[0023] The preferred embodiments of the application will be described below with reference to the accompanying drawings, and it should be understood that the preferred embodiments described herein are only used to illustrate and explain the application, and not to limit the application.

[0024] In addition, the description such as "first", "second" and the like in the present application is only for the purpose of description, and does not mean to specially indicate the order or sequence, nor to limit the application, which is only to distinguish the components or operations described by the same technical terms, and cannot be understood as indicating or implying the relative importance of the indicated technical features or implicitly indicating the number of the indicated technical features. Therefore, the features limited by "first" and "second" can be explicitly or implicitly included at least one of the features. In addition, the technical solutions and technical features of various embodiments can be combined with each other, but it must be based on the realization of a person skilled in the art, and when the combination of technical solutions appears to be contradictory or unachievable, it should be considered that the combination of technical solutions does not exist, nor within the protection scope required by the application.

[0025] The application provides the following embodiments: The application provides a preparation method of a composite antibacterial hydrogel dressing, as shown in Figure 1 The preparation method comprises the following steps: Step 1: preparing a hydrogel matrix; Step 2: weighing CuS nanoparticles, adding deionized water and a dispersing agent, and performing ultrasonic dispersion to prepare a CuS dispersion liquid; after dispersion, the particle size distribution (D90<200 nm) and 72h standing stability (particle size change rate <10%) of the CuS nanoparticles are detected to ensure that the dispersion effect meets the standard. Under the irradiation of 808nm near-infrared laser (power density 1W / cm²), the temperature of the CuS dispersion liquid increases by ≥15℃ within 5min; the light-thermal heating amplitude of the hydrogel after loading needs to be ≥10℃ to ensure the light-thermal antibacterial effect.

[0026] Step 3: Chlorella in logarithmic growth phase is inoculated into the culture medium and cultured to a preset algal cell concentration. After centrifugal collection of algal sludge, the algal sludge is resuspended with sterile deionized water to obtain a chlorella bacterial suspension at a target concentration. Step 4: The hydrogel matrix prepared in step 1 is immersed in the CuS dispersion liquid and subjected to ultrasonic treatment (15-30 min) to load CuS nanoparticles on the surface and in the pores of the hydrogel. After removal, the surface is rinsed with deionized water to remove CuS that is not adsorbed, and is air-dried at room temperature. Step 5: The CuS-loaded hydrogel matrix is immersed in the chlorella bacterial suspension and incubated on a shaking table (rotation speed 50-80 r / min, temperature 25-28℃). A layer of algal cells is formed on the surface of the CuS layer. After removal, the sample is rinsed with sterile deionized water to remove unbound free chlorella, thereby obtaining an intermediate product of CuS and chlorella loading. Step 6: The loading process of steps 4 and 5 is repeated. After each round of loading, the CuS loading amount and the chlorella loading amount in the hydrogel material are detected. If the CuS loading amount does not meet the target requirement, the concentration of the CuS dispersion liquid is adjusted in the next round of loading. If the chlorella loading amount does not meet the target requirement, the concentration of the chlorella bacterial suspension is adjusted in the next round of loading, until both the CuS loading amount and the chlorella loading amount meet the target requirements. Finally, the completed CuS and chlorella-loaded hydrogel material is placed in a sterile culture medium for incubation to obtain a composite antibacterial hydrogel dressing.

[0027] Preferably, in step 1, the dispersant is any one of sodium dodecyl benzene sulfonate, polyvinylpyrrolidone or Tween-80, and the mass fraction of the dispersant in the CuS dispersion liquid is 0.05%-0.2%. The concentration of the prepared CuS dispersion liquid is 50-200 μg / mL.

[0028] Preferably, the ultrasonic power in step 2 is 200-400 W, the ultrasonic power in step 4 is 100-200 W, and the rotation speed of the shaking table during incubation is 50-80 r / min. The ultrasonic power in step 6 is 80-120 W.

[0029] Preferably, the preset algal cell concentration is 1×10 7 -1×10 8 / mL, and the target concentration is 5×10 6 -5×10 7 / mL. The target requirement for the CuS loading amount is 5-20 μg / cm², and the target requirement for the chlorella loading amount is 5×10 5 -5×10 6 / cm².

[0030] Preferably, in step 3, the Chlorella in the logarithmic growth phase is inoculated into the culture medium and cultured to a predetermined algal cell concentration, specifically, the Chlorella in the logarithmic growth phase is inoculated into the BG11 culture medium and cultured under the conditions of light intensity 2000-3000 lx, light-dark cycle 12 h:12 h, and temperature 25-28℃. In step 6, the completed hydrogel material is placed in sterile BG11 culture medium and incubated at 25-28℃ under light intensity 1000-1500 lx for 2-4 h to obtain the composite antibacterial hydrogel dressing.

[0031] Preferably, step 1 comprises: Step 11: The hydrogel base material monomer, crosslinking agent, and initiator are prepared according to the preparation ratio, added to deionized water, ultrasonically dissolved, and uniformly stirred to obtain a clear hydrogel precursor solution with a hydrogel base material monomer concentration of 100-300 g / L; the mass ratio of the hydrogel base material monomer, crosslinking agent, and initiator is 1:(0.005-0.05):(0.001-0.02). Step 12: Dopamine hydrochloride is added to the hydrogel precursor solution, the pH value of the system is adjusted to 8.0-8.5, and the solution is stirred at 25-35℃ for 2-4 h to allow in-situ polymerization of dopamine and uniform dispersion of PDA in the hydrogel precursor solution; by controlling the amount of dopamine hydrochloride added, the mass fraction of PDA in the hydrogel matrix is 0.5%-2%. Step 13: The precursor solution doped with PDA is injected into a mold, and the mold is placed at 30-60℃ for 1-3 h for crosslinking. After demolding, the crude hydrogel matrix is obtained. The crude hydrogel matrix is then soaked in deionized water for 24-48 h, and the deionized water is replaced during the soaking to remove unreacted monomers, crosslinking agents, and byproducts, and finally the hydrogel matrix is obtained.

[0032] The hydrogel matrix material includes natural polymers (such as sodium alginate, gelatin, chitosan, cellulose, etc.) and synthetic polymers (such as polyethylene glycol, polyacrylamide, etc.).

[0033] The CuS nanoparticles can be prepared by existing technologies such as hydrothermal method and template method known in the art, have a particle size D90<200 nm, and are surface-modified with sodium citrate or polyvinylpyrrolidone to improve dispersibility and biocompatibility; or can be directly purchased as a commercially available CuS nanoparticle product.

[0034] Specific implementations are as follows: 1. Hydrogel matrix preparation: The acrylamide (matrix monomer), N, N'-methylenebisacrylamide (crosslinking agent), and ammonium persulfate (initiator) were weighed according to a mass ratio of 1:0.02:0.01, and then added to deionized water to prepare a hydrogel precursor solution with a concentration of 200 g / L by ultrasonic dissolution.

[0035] Dopamine hydrochloride was added to the hydrogel precursor solution, and the pH of the system was adjusted to 8.2. The solution was stirred at 30-31°C for 3 h to allow in-situ polymerization of dopamine to form polydopamine (PDA), and the mass fraction of PDA in the hydrogel matrix was controlled at 1.0%.

[0036] The precursor solution doped with PDA was injected into a polytetrafluoroethylene mold and allowed to crosslink at 40°C for 2 h. After demolding, the crude hydrogel was immersed in deionized water for 48 h (with water changed every 12 h), and unreacted monomers, crosslinking agents, and byproducts were removed to obtain the final hydrogel matrix.

[0037] 2. Preparation of Chlorella vulgaris suspension Chlorella in the logarithmic growth phase was inoculated into BG11 medium and cultured under the conditions of light intensity 2500 lx (50 μmol photons / m² / s), light-dark cycle 12 h:12 h, and temperature 25°C until the concentration of algal cells reached 5×10 7 individuals / mL. The algal slurry was collected by centrifugation, resuspended in sterile deionized water, and adjusted to a target concentration of 1×10 7 individuals / mL.

[0038] 3. CuS nanoparticle loading: The hydrogel matrix was immersed in a CuS dispersion solution and ultrasonically treated at a power of 150 W for 20 min to allow CuS nanoparticles to penetrate and load onto the surface and pores of the hydrogel. After removal, the surface was rinsed with deionized water to remove unabsorbed CuS, and then air-dried at room temperature.

[0039] 4. Chlorella loading: The CuS-loaded hydrogel matrix was immersed in a Chlorella suspension and incubated in a shaking incubator at a speed of 60 r / min and a temperature of 25°C for 2 h to allow Chlorella to adhere and grow on the surface of the CuS layer. After removal, the mixture was rinsed with sterile deionized water to remove unbound free Chlorella, and an intermediate product was obtained.

[0040] 5. Multi-round loading calibration: First-round loading detection: The CuS loading was 8 μg / cm² (target 10 μg / cm²), and the Chlorella loading was 2×10 6 individuals / cm² (target 3×10 6 individuals / cm²).

[0041] Second-round loading adjustment: The concentration of the CuS dispersion solution was increased to 120 μg / mL, and the concentration of the Chlorella suspension was increased to 1.2×10 7 individuals / mL, and steps 4 and 5 were repeated.

[0042] Passing verification: the second round of detection results are CuS loading of 11 μg / cm² and Chlorella loading of 3.2 x 10 6

[0043] 6. Final culture: The loaded hydrogel material is placed in sterile BG11 medium and cultured at 26°C under 1200 lx light for 3 h to prepare the composite antibacterial hydrogel dressing.

[0044] 7. Performance verification: Photothermal performance: the hydrogel loaded with CuS is heated by 12°C within 5 min under 808 nm laser irradiation.

[0045] Stability: after being stored at 4°C for 30 days, the CuS leakage rate is 1.2% and the Chlorella survival rate is 75%.

[0046] Antibacterial performance: the antibacterial rates of Staphylococcus aureus and Escherichia coli are both more than 90%, and the antibacterial rate is further improved to 98% under near-infrared light irradiation.

[0047] The above technical scheme has the beneficial effects of: CuS (photothermal antibacterial), Chlorella (oxygen-producing anti-inflammatory), and hydrogel (adhesion and healing promotion) are combined to construct a triple synergistic system, and the problems of infection, hypoxia, and inflammation are solved simultaneously.

[0048] The dispersion of CuS and the stability of Chlorella are optimized through PDA-mediated interfacial interaction (phenolic hydroxyl groups combined with CuS and Chlorella surface groups), and the inhibition of photothermal on microalgae activity is avoided.

[0049] ​The synergistic mechanism of microalgae and photothermal materials in hydrogels is the key to the therapeutic effect of this composite system. This synergy mainly manifests in the following aspects: First, the functional complementation effect. Microalgae continuously produce oxygen through photosynthesis, improving the hypoxic microenvironment at the wound site, while the thermal effect generated by photothermal materials under laser irradiation can promote blood circulation, further improving tissue oxygen supply. Second, the time sequence synergy effect. By adjusting the light intensity and irradiation time, the time sequence control of the functions of microalgae and photothermal materials can be achieved. Third, the spatial synergy effect. In a double-layer or multi-layer hydrogel structure, microalgae and photothermal materials can function at different levels. Fourth, the synergy of metabolic products. Microalgae not only produce oxygen during photosynthesis, but also secrete various bioactive substances such as polysaccharides, proteins, antioxidants, etc., which synergize with the thermal effect generated by photothermal materials to promote wound healing together. Research has found that Chlorella extract contains a variety of bioactive compounds with antioxidant, anti-inflammatory, and antibacterial properties. Finally, the synergistic effect of immune regulation. Microalgae and photothermal materials both have immune regulation functions, and their synergistic effect can more effectively regulate the immune microenvironment of the wound (Dai Yunli. Synthesis of nano cerium oxide based on green chlorella and its antibacterial application in constructing antibacterial hydrogel coating for catheters [D]. Qingdao: Shandong University, 2024).

[0050] The present application breaks through the uneven load problem caused by physical mixing in the prior art through the closed-loop mechanism of "multi-round load-detection-calibration". It can accurately regulate the load of CuS nanoparticles and Chlorella, ensure the uniform penetration of nanoparticles in the pores of the hydrogel, and stabilize the CuS load at 5-20 μg / cm² and the Chlorella load at 5×10 5 -5×10 6 cm², effectively avoiding component aggregation.

[0051] The present application forms an ordered functional layer of CuS nanoparticles and Chlorella in the hydrogel through a step-by-step loading process, rather than simple physical mixing. This structure ensures that the photothermal sterilization effect of CuS and the oxygen production and anti-inflammatory effect of Chlorella can synergize, significantly improving the removal ability of drug-resistant bacteria and biofilms, while improving the wound microenvironment and accelerating the healing process.

[0052] In one embodiment, step 4 of the target experimental group is selected for benchmarking experiments to detect the ultrasonic duration, CuS dispersion liquid temperature, CuS dispersion liquid viscosity, and CuS dispersion liquid conductivity. And according to the benchmark to determine the test results, construct the ultrasonic time- experimental CuS dispersion liquid conductivity curve and ultrasonic time- experimental CuS dispersion liquid temperature curve, according to the load cycle, the ultrasonic time- experimental CuS dispersion liquid conductivity curve and ultrasonic time- experimental CuS dispersion liquid temperature curve are divided into a plurality of first sub curve and second sub curve;Each first sub curve and each second sub curve correspond to a load cycle; And construct the CuS dispersion liquid viscosity sequence corresponding to each load cycle according to the detection time sequence; And set up gradient experiment to build conductivity ratio range- viscosity ratio range- the target ultrasonic power of each load relationship.

[0053] In the process development stage, for the determined target experiment group (i.e. the process scheme of final scale production), carry out benchmarking experiment (corresponding to the benchmark ultrasonic power of each load, corresponding to the process scheme of final scale production, the minimum value of ultrasonic power range can be taken to avoid excessive power), ultrasonic time, CuS dispersion liquid temperature, CuS dispersion liquid viscosity, CuS dispersion liquid conductivity are detected in the benchmark experiment; The abscissa of ultrasonic time- experimental CuS dispersion liquid conductivity curve and ultrasonic time- experimental CuS dispersion liquid temperature curve is ultrasonic time, and the ordinate is the experimental CuS dispersion liquid conductivity detection result corresponding to the abscissa in the benchmark experiment and the CuS dispersion liquid temperature detection result corresponding to the abscissa in the benchmark experiment.

[0054] In order to match the process of multiple load, the ultrasonic time- experimental CuS dispersion liquid conductivity curve and ultrasonic time- experimental CuS dispersion liquid temperature curve are cut according to the load cycle, and the first sub curve and the second sub curve corresponding to each load are generated.

[0055] The step 4 includes: Step 41: obtain the benchmark ultrasonic power corresponding to each load corresponding to the benchmarking experiment; Step 42: immerse the hydrogel matrix prepared in step 1 in CuS dispersion liquid, and ultrasonic treatment is carried out with the benchmark ultrasonic power corresponding to the first load; And detect the CuS dispersion liquid conductivity for many times in the first time, and detect the CuS dispersion liquid temperature at the beginning and end of the first time;Determine the actual average conductivity change rate of CuS dispersion liquid, and determine the average conductivity change rate deviation, when the average conductivity change rate deviation meets the requirement, continue to carry out ultrasonic treatment with the benchmark ultrasonic power corresponding to each load;The first time is the total ultrasonic time of the first load with a preset proportion; Step 43: When the average conductivity rate of change deviation does not meet the requirements, based on the detection result detected in step 43 and combined with the CuS dispersion liquid viscosity sequence and the first sub-curve, the predicted conductivity range of the first round of load and the predicted viscosity range of the CuS dispersion liquid are determined, and based on the predicted conductivity range of the first round of load and the predicted viscosity range of the CuS dispersion liquid, the actual conductivity difference and the actual viscosity difference are determined, and combined with the actual conductivity difference and the actual viscosity difference, the actual conductivity ratio and the actual viscosity ratio are determined; Based on the actual conductivity ratio and the actual viscosity ratio, the preset conductivity ratio range-viscosity ratio range-target ultrasonic power of each round of load relationship determines the current target ultrasonic power of each round of load; continue to carry out ultrasonic treatment with the current target ultrasonic power of each round; The benchmark determination experiment process further comprises: Each second sub-curve is divided into slope analysis, each second sub-curve is divided into different temperature characteristic segments, and a preset temperature node value and a corresponding ultrasonic time threshold value are bound for each temperature characteristic segment; Step 43 further comprises: during the ultrasonic treatment process with the current target ultrasonic power of each round, the CuS dispersion liquid temperature corresponding to each round of load is detected multiple times, when the CuS dispersion liquid temperature enters the corresponding temperature characteristic segment, the ultrasonic time control rule of this round is triggered: If the temperature reaches the preset node value corresponding to the characteristic segment, the cumulative time of the current ultrasonic is strictly limited to not more than the time threshold value bound by the characteristic segment; if the temperature exceeds the highest characteristic segment node value of the second sub-curve of this round, the current ultrasonic treatment is immediately terminated.

[0056] The predicted conductivity range of the first round of load ; The CuS dispersion liquid conductivity detected for the first time in step 43; From the first sub-curve corresponding to the first round of load, the ratio of the preset proportion of the average conductivity rate of change to the average conductivity rate of change before the preset proportion is determined, which is denoted as the initial conductivity rate of change ratio; = The CuS dispersion liquid conductivity detected for the last time in step 43 - (1-preset proportion) x the ultrasonic time of the first round of load x the initial conductivity rate of change ratio x the actual average conductivity rate of change of the CuS dispersion liquid determined in step 43; The predicted viscosity range of the first round of load ; The CuS dispersion liquid viscosity detected for the first time in step 43; From the CuS dispersion liquid viscosity sequence, the ratio of the average viscosity rate of change after the preset proportion to the average viscosity rate of change before the preset proportion is determined, which is denoted as the initial viscosity rate of change ratio; = Step 43 last detection of CuS dispersion liquid viscosity - (1 - preset ratio) x the first round of load ultrasonic duration x initial viscosity rate of change ratio x Step 43 determined CuS dispersion liquid actual average viscosity rate of change; The first round of load ultrasonic duration is the first round of load ultrasonic duration in the benchmark determination experiment; In the benchmark determination experiment, the end of each round of loading is determined only by the conductivity change characteristics of the CuS dispersion liquid: during the ultrasonic treatment process, the real-time change of conductivity is continuously monitored, when the conductivity is lower than the preset threshold (such as ≤0.05 mS / cm·min; the threshold is determined by the conductivity change rate when the CuS nanoparticle loading rate reaches saturation in the pre-experiment) and stable (i.e. the conductivity no longer decreases significantly with time), it indicates that the CuS nanoparticles in the hydrogel pores have reached the saturated loading state, at this time it can be determined that the round of loading is over.

[0057] Average conductivity rate of change deviation = CuS dispersion liquid actual average conductivity rate of change - "CuS dispersion liquid average conductivity rate of change corresponding to the ultrasonic duration of the first round of loading when reaching the preset ratio in the first sub-curve corresponding to the first round of loading"; The deviation requirement is: the ratio of the average conductivity rate of change deviation to "the CuS dispersion liquid average conductivity rate of change corresponding to the ultrasonic duration of the first round of loading when reaching the preset ratio in the first sub-curve corresponding to the first round of loading" is less than or equal to 0.05; The preset ratio is 10-30%; an exemplary value is 20%, which is determined by the stability of the conductivity change in the pre-experiment; The first round of load benchmark conductivity range (the difference between the initial value and the final value of the first round of load benchmark conductivity range can be determined as the benchmark conductivity difference) and the first round of load benchmark viscosity range (the difference between the initial value and the final value of the first round of load benchmark viscosity range can be taken as the benchmark viscosity difference) reflect the actual loading effect state of the current first round of loading under the benchmark ultrasonic power; The first round of load predicted conductivity range and the first round of load CuS dispersion liquid predicted viscosity range can respectively determine the actual conductivity difference (the difference between the initial value and the final value of the first round of load predicted viscosity range can be determined as the actual conductivity difference) and the actual viscosity difference (the difference between the initial value and the final value of the first round of load predicted viscosity range can be taken as the benchmark viscosity difference); Determine the actual conductivity ratio of the actual conductivity difference and the benchmark conductivity difference, and determine the actual viscosity ratio of the actual viscosity difference and the benchmark viscosity difference; The preset conductivity ratio range-viscosity ratio range-pre-set adjustment ratio relationship of each load determines the current target ultrasonic power of each load based on the conductivity ratio and the viscosity ratio. The preset conductivity ratio range-viscosity ratio range-pre-set adjustment ratio relationship of each load determines the current target ultrasonic power of each load based on the conductivity ratio and the viscosity ratio. The test conductivity ratio corresponding to the target ultrasonic power is greater than 1 (between 1 and 1.1), and the test viscosity ratio corresponding to the target ultrasonic power is greater than 1 (between 1 and 1.1). The ratio of the maximum value to the minimum value of the slope of each temperature characteristic segment satisfies a preset ratio range (such as 1.0-1.2), and the temperature of each temperature characteristic segment is continuous. The maximum allowed ultrasonic cumulative duration of each temperature characteristic segment is pre-set. Each temperature characteristic segment is bound to a preset temperature node value, which is selected from the endpoint temperature of each temperature characteristic segment. In the pre-experiment of each load, the complete ultrasonic duration and CuS dispersion liquid temperature data are collected at a fixed baseline ultrasonic power, and the continuous interval with a slope fluctuation that meets the preset ratio range (such as 1.0-1.2) is selected as a temperature characteristic segment through slope analysis. Then, the longest effective ultrasonic duration that meets both stable temperature change and load effect in the characteristic segment is taken as the ultrasonic duration threshold bound to the characteristic segment, and the threshold of each round is determined independently to adapt to its unique temperature law.

[0058] In addition, the risk state can be judged according to the limit state of the above prediction range, and the detection frequency can be increased according to the judgment result (the detection is compared with the baseline value corresponding to the ultrasonic duration of the corresponding sub-curve, and if the deviation does not meet the requirement, an early warning is given).

[0059] The first load: the baseline ultrasonic power is 100-120 W. The second load: the baseline ultrasonic power is 120-150 W. 3rd round load: reference ultrasonic power 150-180W; The beneficial effects of the above technical solutions are: 1. By establishing the first and second sub-curves (conductivity and temperature) of each round, a precise "reference scale" is provided for subsequent process development. The complex process of multiple rounds of load is decomposed into independent single-round reference units, avoiding the ambiguity of multiple round data.

[0060] This scheme builds a more accurate and efficient single-round load process control system through the closed-loop logic of "preset proportion short-time measurement → generating the first round of overall prediction range based on measured data → dynamically adjusting power based on the conductivity / viscosity change of the whole round load", achieving precise control after short-time measurement for each batch or even each production.

[0061] 2. Selecting the minimum value of the reference ultrasonic power as the reference, it not only avoids the energy waste and the risk of excessive damage to the hydrogel pores caused by high power, but also provides an "low energy consumption, high stability" initial anchor point for mass production process through multi-parameter detection of the reference experiment. This design greatly reduces the trial and error cost at the initial stage of mass production, while providing sufficient optimization space for subsequent dynamic power adjustment.

[0062] Each round of load can match the exclusive conductivity and temperature change reference, ensuring the traceability and comparability of process status in multiple consecutive production, effectively solving the control problem of batch fluctuation in mass production.

[0063] Step 41: Assign independent reference ultrasonic power to each round of load, accurately match the initial power according to the pore state of hydrogel and the characteristics of dispersion liquid for different rounds, and ensure reliable production.

[0064] Step 42: Conductivity and temperature detection and deviation judgment in the pre-experiment stage are carried out in the first time (preset proportion of total ultrasonic time). By calculating the deviation between the actual average conductivity change rate and the reference rate, the process deviation risk can be identified at the beginning of the first round of load. When the deviation meets the requirements, the reference power is continued to be used to ensure the stability of the process; when the deviation exceeds the threshold, timely adjustment is triggered to avoid the subsequent chain problems caused by initial deviation, and the fault tolerance of single-round production is improved.

[0065] Step 43: Based on the detection results and the predicted conductivity range and viscosity range calculated by the reference curve, a quantitative basis is provided for power adjustment. Combined with the ratio relationship established by gradient experiment, the optimal ultrasonic power corresponding to the current load state can be accurately located, realizing "on-demand energy supply". This mechanism not only can quickly correct process deviation, but also can avoid energy waste caused by blind adjustment, so that the single-round load is always in an efficient and stable state.

[0066] 3. Through the slope fluctuation range (such as 1.0-1.2), the temperature characteristic section is divided, and the preset node value and the time length threshold value are bound, so that the continuous temperature change is converted into a discrete controllable unit. This design changes the temperature control from "passive response" to "active prediction", which can identify the risk of abnormal temperature rise in advance and avoid the aggregation of CuS particles or the destruction of hydrogel structure caused by overheating.

[0067] When the temperature reaches the preset node value, the cumulative time length of the current ultrasonic is strictly limited; when the temperature exceeds the highest characteristic section node value, the ultrasonic treatment is immediately terminated. This strong control mechanism fundamentally eliminates the risk of overheating, ensures the safety of product quality, and also avoids the energy loss caused by invalid ultrasonic, further improving the safety and economy of production.

[0068] In one embodiment, step 12 comprises: Step 121: detecting the actual temperature and the actual viscosity of the hydrogel precursor solution obtained in step 11; and combining the benchmark viscosity-temperature mapping table of the hydrogel precursor solution determined by the pre-experiment (the temperature of the hydrogel precursor solution obtained in step 11-the benchmark viscosity mapping table of the hydrogel precursor solution obtained in step 11) to determine the actual viscosity coefficient; Actual viscosity coefficient = actual viscosity of hydrogel precursor solution obtained in step 11 ÷ "actual temperature of hydrogel precursor solution obtained in step 11 in the corresponding viscosity of the benchmark viscosity-temperature mapping table"; Step 121 applies the benchmark viscosity mapping table of the hydrogel precursor solution obtained in step 11 corresponding to the current step 11 raw materials and process parameters; it is a "temperature-standard viscosity" corresponding relationship table established exclusively for the raw material formula and preparation process used in the current batch in the pre-experiment stage.

[0069] The pre-experiment stage is a verification experiment carried out before the formal production batch to establish the process benchmark. In this stage, multiple standard hydrogel precursor solutions will be prepared according to the established raw material formula and preparation process of step 11. These solutions represent the "ideal state" under the current process, and their performance parameters will serve as the reference benchmark for subsequent production.

[0070] Step 122: obtaining the process requirement stirring speed range of step 12, selecting the target sub-speed range based on the actual viscosity coefficient and the process requirement stirring speed range of step 12, and determining the initial temperature of the solution based on the actual viscosity coefficient; The process requirement stirring speed range of step 12: is the allowable speed interval set based on pre-experiment and process experience for the polymerization reaction of step 12, which can meet the production requirements (meet the production quality and efficiency); The process requirement stirring speed range of step 12 includes: the process requirement stirring speed range of the initial polymerization period (120-180 rpm), the process requirement stirring speed range of the main polymerization period (a first proportion of the process requirement stirring speed range of the initial polymerization period, the first proportion being 0.6-0.8), and the process requirement stirring speed range of the final polymerization period (a second proportion of the process requirement stirring speed range of the initial polymerization period, the second proportion being 0.3-0.5); The target sub-speed range is selected based on the actual viscosity coefficient and the process requirement stirring speed range of step 12, and the solution initial temperature is determined based on the actual viscosity coefficient: both are process rules formed by system testing and multiple batch verifications in the pre-experiment stage; the corresponding relationship between the sub-speed range and the viscosity coefficient range is determined based on the test results of mass transfer efficiency and shear force influence under different viscosities: when the viscosity coefficient is high, a high-speed sub-range is matched to intensify mass transfer, and when the viscosity coefficient is low, a low-speed sub-range is matched to avoid excessive shear; the corresponding relationship between the viscosity coefficient and the initial temperature is determined based on the intrinsic characteristics of the viscosity of the polymer solution decreasing with the increase of temperature and the test results of reaction kinetics: when the viscosity coefficient is high, a slightly higher initial temperature is matched to reduce the viscosity and improve the reaction rate, and when the viscosity coefficient is low, a slightly lower initial temperature is matched to maintain the reaction stability, and the two together constitute the basis for precise control in the initial stage of the polymerization reaction. Step 123: dopamine hydrochloride is added to the hydrogel precursor solution, the dopamine hydrochloride is stirred to dissolve, the pH value of the system is adjusted to 8.0-8.5, the temperature of the hydrogel precursor solution is adjusted to the solution initial temperature, and the stirring in the initial polymerization stage is carried out at a preselected value in the target sub-speed range until the temperature adjustment condition (actual temperature≥solution initial temperature+pre-set temperature, the pre-set temperature being 0.8-1.3 ℃) is met, and the actual temperature is less than the solution initial temperature+pre-set temperature; The solution conductivity and the solution temperature are detected multiple times during the stirring process, and a multi-parameter correlation matrix including the stirring time, the solution conductivity, and the solution temperature is constructed; Step 124: the conductivity change rate one at the time point meeting the temperature adjustment condition is determined, the time point two at which the absolute difference between the conductivity change rate and the conductivity change rate one is greater than the pre-set conductivity change rate (the value range being 0.1-0.2 μS / (cm·min)) for the first time after meeting the temperature adjustment condition is determined, and the conductivity lag duration is determined. The conductivity lag duration = time point two - time point meeting the temperature adjustment condition; and the average conductivity change rate is determined based on the time-solution conductivity sequence. Step 125: If the conductivity hysteresis time exceeds the reference hysteresis time (which is the typical hysteresis time of conductivity with respect to temperature measured in pre-experiments, usually 2-5 minutes; the reference hysteresis time can be the average value of pre-experiments): dynamically increase the initial polymerization stirring speed in the target sub-speed range (the increase amplitude is 5%-10% of the current speed) to strengthen heat transfer and shorten the response hysteresis of conductivity to temperature.

[0071] If the average conductivity change rate deviates from the preset rate interval: dynamically fine-tune the reaction temperature in the range of 25-35°C (further lower the temperature by 0.2-0.5°C if the rate is too fast, or further increase the temperature by 0.2-0.5°C if the rate is too slow) to accurately control the dopamine polymerization rate.

[0072] Step 126: The main polymerization period is stirred at the first proportion of the final stirring speed in step 125, and the final polymerization period is stirred at the second proportion of the final stirring speed in step 125; In this embodiment, step 11 can be performed once after each batch, and the subsequent production can be based on the final stirring speed and initial solution temperature determined by the above execution results, or it can be performed each time.

[0073] The beneficial effects of the above technical solutions are: This step detects the actual viscosity of the current batch in real time and accurately matches the pre-experiment-specific reference viscosity-temperature mapping table, which not only quickly locks the appropriate initial process window, but also avoids trial-and-error costs caused by raw material fluctuations from the source, effectively shortens production preparation time, and sets initial parameters for each batch based on its own raw material characteristics, significantly reducing performance deviations between batches and improving product consistency.

[0074] Step 122 automatically selects the target sub-speed range and determines the initial temperature based on the actual viscosity coefficient without relying on human experience; high viscosity matches high speed to strengthen mass transfer, and low viscosity matches low speed to avoid excessive shear, improving the uniformity of dispersion in the initial polymerization stage and reducing the risk of local polymerization, while the accurately matched initial temperature also shortens the induction period of the polymerization reaction by 5%-8%, making the overall production cycle more controllable.

[0075] This step builds a multi-parameter correlation matrix while stirring the material, records the complete time series of stirring time, conductivity, temperature, etc. in real time, and provides solid data support for subsequent hysteresis time calculation and rate judgment, and can better capture the actual change trend of temperature or conductivity at the beginning of the reaction; By dynamically adjusting the speed and temperature, when the conductivity hysteresis time exceeds the standard, increasing the speed can strengthen heat transfer and shorten the hysteresis time by 10%-15%, ensuring that the temperature and conductivity response are more synchronized; the dynamic adjustment mechanism avoids excessive stirring or ineffective heating.

[0076] Step 126 switches the speed of the main polymerization period and the finishing polymerization period by the first ratio and the second ratio; the medium speed in the main polymerization period ensures the smooth reaction, and the low speed in the finishing period reduces the network disturbance, so that the porosity deviation of the final product is reduced, and the antibacterial performance is more uniform; at the same time, the operation of reducing the speed in stages also reduces the continuous high load operation of the equipment.

[0077] Obviously, those skilled in the art can make various modifications and variations to the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application belong to the scope of the claims of the present application and their equivalent technologies, the present application also intends to include these modifications and variations.

Claims

1. A method of preparing a composite antimicrobial hydrogel dressing, characterized by: The method comprises the following steps: Step 1: preparing a hydrogel matrix; Step 2: weighing CuS nanoparticles, adding deionized water and a dispersant, and performing ultrasonic dispersion to obtain a CuS dispersion liquid; Step 3: inoculating Chlorella in logarithmic growth phase into a culture medium, culturing to a preset algal cell concentration, centrifuging to collect algal sludge, and resuspending the algal sludge with sterile deionized water to obtain a Chlorella bacterial suspension with a target concentration; Step 4: immersing the hydrogel matrix prepared in Step 1 into the CuS dispersion liquid, performing ultrasonic treatment, loading CuS nanoparticles on the surface and pores of the hydrogel, and then taking out the hydrogel, washing the surface of the hydrogel with deionized water to remove CuS not adsorbed on the surface, and air-drying at room temperature; Step 5: immersing the CuS-loaded hydrogel matrix into the Chlorella bacterial suspension, incubating on a shaking table, and forming an algal cell layer on the surface of the CuS layer; then taking out the hydrogel, washing with sterile deionized water to remove free Chlorella not combined, and obtaining an intermediate product of the CuS-loaded Chlorella; Step 6: repeating the loading process of Step 4 and Step 5 until the loading amount of CuS and the loading amount of Chlorella both meet the target requirements; Step 7: placing the completed CuS-loaded hydrogel material in sterile culture medium for static culture to obtain a composite antibacterial hydrogel dressing.

2. A method of preparing a composite antimicrobial hydrogel dressing according to claim 1, characterized in that: After each round of loading, the loading amount of CuS and the loading amount of Chlorella in the hydrogel material are detected, and if the loading amount of CuS does not meet the requirements, the concentration of the CuS dispersion liquid is adjusted in the next round of loading; and if the loading amount of Chlorella does not meet the requirements, the concentration of the Chlorella bacterial suspension is adjusted in the next round of loading.

3. A method of preparing a composite antimicrobial hydrogel dressing according to claim 1, characterized in that: In Step 1, the dispersant is any one of sodium dodecyl benzene sulfonate, polyvinylpyrrolidone or Tween-80, and the mass fraction of the dispersant in the CuS dispersion liquid is 0.05% to 0.2%. The concentration of the prepared CuS dispersion liquid is 50 to 200 μg / mL.

4. The method of claim 1, wherein the method further comprises the step of: 4.

1. adding a crosslinking agent to the mixture of step 3.

1. to form the composite antimicrobial hydrogel dressing. The ultrasonic power in Step 2 is 200 to 400 W, the ultrasonic power in Step 4 is 100 to 200 W, the rotation speed of the shaking table during the incubation process is 50 to 80 r / min, and the ultrasonic power in Step 6 is 80 to 120 W.

5. The method for preparing a composite antibacterial hydrogel dressing according to claim 1, characterized in that: The preset algal cell concentration is 1×10 7 ~ 1×10 8 The target concentration is 5×10 6 ~ 5×10 7 The target CuS loading requirement is 5~20 μg / cm², and the target Chlorella loading requirement is 5×10 5 ~ 5×10 6 / cm².

6. The method of claim 1, wherein the method further comprises: In Step 3, the Chlorella in logarithmic growth phase is inoculated into the culture medium, and the culture is performed until the preset algal cell concentration is reached, specifically: the Chlorella in logarithmic growth phase is inoculated into BG11 culture medium, and the culture is performed under the conditions of light intensity of 2000 to 3000 lx, light and dark cycle of 12 h:12 h, and temperature of 25 to 28 ℃. In Step 6, the completed CuS-loaded hydrogel material is placed in sterile BG11 culture medium, and static culture is performed under the conditions of temperature of 25 to 28 ℃ and light intensity of 1000 to 1500 lx for 2 to 4 h to obtain the composite antibacterial hydrogel dressing.

7. The method for preparing a composite antibacterial hydrogel dressing according to claim 1, characterized in that: Step 1 comprises: Step 11: adding hydrogel matrix monomers, a crosslinking agent and an initiator into deionized water according to the preparation ratio, performing ultrasonic dissolution and stirring to obtain a clear hydrogel precursor solution with a hydrogel matrix monomer concentration of 100 to 300 g / L; the mass ratio of the hydrogel matrix monomers, the crosslinking agent and the initiator is 1:0.005 to 0.05:0.001 to 0.

02. Step 12: Add dopamine hydrochloride to the hydrogel precursor solution, adjust the pH of the system to 8.0–8.5, and stir the reaction at 25–35°C for 2–4 hours to allow dopamine to polymerize in situ to form PDA and uniformly disperse it in the hydrogel precursor solution; by controlling the amount of dopamine hydrochloride added, the mass fraction of PDA in the hydrogel matrix is ​​0.5%–2%; Step 13: Inject the PDA-doped precursor solution into the mold and allow it to stand at 30-60°C for 1-3 hours for crosslinking. After demolding, a crude hydrogel matrix is ​​obtained. The crude hydrogel matrix is ​​then soaked in deionized water for 24-48 hours, during which time the deionized water is replaced to remove unreacted monomers, crosslinking agents and byproducts, resulting in the final hydrogel matrix.

8. The method of claim 1, wherein the method further comprises: In the experimental phase, step 4 of the target experimental group was selected to conduct a baseline determination experiment. During the baseline determination experiment, the ultrasonic duration, CuS dispersion temperature, CuS dispersion viscosity, and CuS dispersion conductivity were measured. ​ Based on the benchmark, the experimental test results were determined, and ultrasonic duration-experimental CuS dispersion conductivity curve and ultrasonic duration-experimental CuS dispersion temperature curve were constructed. According to the load cycle, the ultrasonic duration-experimental CuS dispersion conductivity curve and ultrasonic duration-experimental CuS dispersion temperature curve were divided into multiple first sub-curves and second sub-curves; each first sub-curve and each second sub-curve correspond to one load cycle. And construct a viscosity sequence of CuS dispersions for each load cycle, arranged in chronological order of detection time; A gradient experiment was set up to establish the relationship between the conductivity ratio range, the viscosity ratio range, and the target ultrasonic power per load.

9. The method for preparing a composite antibacterial hydrogel dressing according to claim 7, characterized in that: Step 4 includes: Step 41: Obtain the baseline ultrasonic power corresponding to each load in the baseline determination experiment; Step 42: Immerse the hydrogel matrix obtained in Step 1 into the CuS dispersion and perform ultrasonic treatment with the reference ultrasonic power corresponding to the first round of loading. The conductivity of the CuS dispersion was measured multiple times within the first time period; the actual average conductivity change rate of the CuS dispersion was determined, and the deviation of the average conductivity change rate was determined. When the deviation of the average conductivity change rate met the requirements, ultrasonic processing was continued with the corresponding reference ultrasonic power for each round; the first time period was the total ultrasonic time of the first round of load with a preset ratio. Step 43: When the deviation of the average conductivity change rate does not meet the requirements, based on the detection results of step 42 and combined with the viscosity sequence of the CuS dispersion and the first sub-curve, determine the predicted conductivity range and the predicted viscosity range of the CuS dispersion for the first round of loading, and determine the actual conductivity difference and the actual viscosity difference based on the predicted conductivity range and the predicted viscosity range of the CuS dispersion for the first round of loading, and determine the actual conductivity ratio and the actual viscosity ratio based on the actual conductivity difference and the actual viscosity difference. Based on the actual conductivity ratio and the actual viscosity ratio, the current target ultrasonic power for each load is determined by the preset conductivity ratio range, viscosity ratio range, and target ultrasonic power relationship for each load; ultrasonic processing continues with the current target ultrasonic power for each load.

10. A method of preparing a composite antimicrobial hydrogel dressing according to claim 9, characterized in that: The baseline determination experiment process also includes: Each second sub-curve is divided into different temperature characteristic segments, and each temperature characteristic segment is bound with a preset temperature node value and a corresponding ultrasonic duration threshold value; Step 43 further comprises: during the ultrasonic treatment at the current target ultrasonic power of each round, the CuS dispersion liquid temperature corresponding to each round of load is detected multiple times, and when the CuS dispersion liquid temperature enters the corresponding temperature characteristic segment, the ultrasonic duration control rule of the round is triggered: If the temperature reaches the preset node value corresponding to the characteristic segment, the cumulative duration of the current round of ultrasonic treatment is strictly limited to not more than the duration threshold value bound by the characteristic segment; if the temperature exceeds the node value of the highest characteristic segment of the second sub-curve of the current round, the current round of ultrasonic treatment is immediately terminated.

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