A photocatalytic dual nanoenzyme gel dressing for wound healing

Abstract

The invention discloses a photocatalytic double nanoenzyme gel dressing for wound healing. The invention uses a hydrothermal method to prepare an iron-doped molybdenum selenide nanomaterial, and uses the characteristics of the liquid part having reducing and photocatalytic activity, and the solid part having nanoenzyme simulating peroxidase activity. The liquid part is used as a reducing agent, combined with a white radish extract having astringent and hemostatic properties, and having antibacterial chitosan and polyethylene glycol as gel molecular skeletons, and the solid part nanoenzyme catalyzes the oxidation of phenolic substances in the white radish extract to prepare chitosan silver nanogel dressing. The prepared iron-doped molybdenum selenide has a strong simulated peroxidase activity of the photocatalytic defective nanoenzyme, produces toxic hydroxyl free radicals, and has the antibacterial effect of silver nano and gel base, achieving a high-efficiency antibacterial effect; at the same time, the iron-doped molybdenum selenide has a simulated superoxide dismutase activity, combined with the astringent and hemostatic effect of the white radish extract, the gel dressing can effectively heal wounds infected with bacteria.

Description

Technical Field

[0001] The invention relates to the technical field of nano material antibacterial, in particular to a photocatalytic dual nano enzyme gel dressing for wound healing. Background Art

[0002] As the largest organ of the human body, the skin is the first line of defense of the human body's natural defense system, which can prevent the invasion of external microorganisms and protect internal tissues. However, the skin is susceptible to various types of trauma, such as burns, scalds, and tears. Although it can repair itself, it has certain limitations. Therefore, wound dressings have become an effective auxiliary means to promote skin tissue repair or healing. Hydrogels have been considered to be promising wound dressings because of their ability to provide a moist environment, absorb wound exudates, and resist bacteria. Since bacteria and reactive oxygen free radicals can cause severe inflammatory reactions, thereby delaying wound healing, antibacterial and antioxidant properties are important indicators of wound dressings. Bletill, a dried tuber of the orchid plant Bletill astriata (Thunb.) Reichb. f., tastes sweet, bitter, and astringent, and is cold in nature. It belongs to the stomach meridian, lung meridian, and liver meridian, and has the effects of astringing sores, nourishing the lungs, reducing swelling, stopping bleeding, and promoting tissue regeneration. Chitosan has good biocompatibility, biodegradability, low toxicity, non-antigenicity, antimicrobial activity, coagulation and hemostasis, making it an important substrate for wound dressings. Nanozymes have been widely explored to achieve better antibacterial effects due to their ability to mimic peroxidase (POD) activity. They can catalyze hydrogen peroxide (H 2 O 2 ) generates hydroxyl radicals (·OH), which have higher antibacterial activity and can minimize the 2 O 2 toxicity. In particular, ·OH can cause initial oxidative damage to cell walls and cell membranes, and when combined with photothermal therapy (PTT), i.e., near-infrared light (NIR) conversion to induce hyperthermia, it overcomes the defects of each individual antibacterial model and exhibits enhanced antibacterial activity. As a reductive nanomaterial, carbon dots can also be activated under light irradiation to generate photoinduced charges and obtain active intermediates, increasing their photocatalytic effect. Molybdenum selenide (MoSe 2 ) As a two-dimensional nanomaterial, it has the advantages of large specific surface area, easy surface modification, and good biocompatibility. 2 The excellent absorption in the NIR range and POD-like nanozyme properties make it possible to be applied in non-invasive antibacterial treatment methods. However, it is still necessary to combine natural product extracts with inorganic nanomaterials to give full play to their excellent antibacterial, antioxidant and photocatalytic properties for the preparation of wound healing gel dressings. Summary of the invention

[0003] The present invention provides a wound healing photocatalytic dual nanozyme gel dressing, which utilizes the dual nanozyme activity produced by nanozymes. One is Fe-MoSe 2 / AgNPs catalyze H 2 O 2 Produces toxic hydroxyl radicals (·OH), which have bactericidal activity. Second, Fe-MoSe 2 / AgNPs can simulate superoxide dismutase (SOD) activity under neutral conditions. Combined with the astringent and hemostatic effect of Bletilla striata extract, the antibacterial, antioxidant and anti-inflammatory effects are further enhanced under near-infrared (NIR) radiation. In vitro antibacterial and animal tests have been fully demonstrated.

[0004] The present invention discloses a photocatalytic dual nanoenzyme gel dressing for wound healing. The present invention prepares an iron-doped molybdenum selenide nanomaterial (Fe-MoSe 2 The liquid part (carbon dots) has reducing and photocatalytic activity, and the solid part has nanozyme mimicking peroxidase (POD) activity. The liquid part is mixed with pomegranate peel water extract with antioxidant and anti-inflammatory properties as a reducing agent, chitosan (CS) and polyethylene glycol (PEG) with antibacterial properties as a gel molecular skeleton, and the solid part Fe-MoSe 2 (Nanozyme) catalyzed oxidation of phenolic substances in Bletilla striata extract to prepare silver nanoparticles (AgNPs) gel dressing (Fe-MoSe 2 / AgNPs). Utilizing Fe-MoSe 2 The strong simulated peroxidase (POD) activity of the photocatalytic defective nanozyme is effectively converted into toxic hydroxyl radicals (·OH) by combining with low concentrations of sodium persulfate. The introduction of carbon dots strengthens the transfer of photoelectrons and improves the photocatalytic effect. At the same time, the antibacterial effect of AgNPs and gel substrate is utilized to achieve a high-efficiency antibacterial effect. 2 It has the ability to simulate superoxide dismutase (SOD) activity, combined with the astringent and hemostatic effects of Bletilla striata extract, Fe-MoSe 2 / AgNPs gel dressing can effectively heal bacterial-infected wounds.

[0005] The present invention prepares the photocatalytic dual nanoenzyme gel dressing for wound healing, and the steps are as follows:

[0006] (1) Iron-doped molybdenum selenide nanomaterials (Fe-MoSe 2 ) Preparation: 0.3 - 0.5 g sodium selenate, 1.5 - 2.0 g L-cysteine, 0.1 - 0.2 g FeSO 4 7H 2O was dissolved in 50-80 mL deionized water, ultrasonically treated for 10-15 min, and then transferred to a polytetrafluoroethylene tank, calcined in a muffle furnace at 200-220 °C for 18-24 h, centrifuged, and filtered through a 0.22 μm filter membrane to obtain the supernatant, i.e., the liquid part (Fe, Mo, Se-CDs). The solid part was washed with 0.1 mol / L dilute sulfuric acid, anhydrous ethanol, and deionized water in turn, and vacuum dried to obtain Fe-MoSe 2；

[0007] (2) Fe-MoSe 2 Preparation of / AgNPs gel dressing: Add AgNO3 solution and sodium persulfate solution to polyethylene glycol 400 aqueous solution, stir for 40 min, and cool to room temperature to prepare solution A; mix Fe, Mo, Se-CDs and Bletilla striata extract in a volume ratio of 1:10 and stir. 2 Stir and disperse it into it to obtain liquid B; mix 5 parts by weight of liquid A and 1 part by weight of liquid B, stir at room temperature and avoid light for 30 minutes to obtain liquid C; prepare chitosan CS solution with 1% acetic acid, take CS solution and liquid C in a volume ratio of 4:1 and mix and stir for 10 minutes to obtain Fe-MoSe 2 / AgNPs gel dressing. The conditions were exactly the same to prepare Fe, Mo, Se-CDs and Fe-MoSe 2 Gel dressing. The concentration of Bletilla striata extract is 2-3 mg / mL, the concentration of polyethylene glycol 400 is 10-12% (w / v), the concentration of AgNO3 solution is 2-3 mg / mL, the concentration of sodium persulfate solution is 0.001-0.005 mg / mL, the concentration of CS is 2-3% (w / v), the concentration of Fe, Mo, Se-CDs is 0.1-0.3 mg / mL, and the concentration of Fe-MoSe 2 The concentration is 0.1-0.5mg / mL.

[0008] The Bletilla striata extract is prepared by the following method: crush the dried Bletilla striata, pass it through a 40-60 mesh sieve, weigh 0.1-0.2 g of Bletilla striata powder, add 800-100 mL of 40%-50% ethanol, ultrasonicate at 50° C. for 25-30 min, centrifuge, take the supernatant, and bake it in an oven at 60-70° C. for 1-2 h to obtain the Bletilla striata extract, which is prepared with pure water to the required concentration as required.

[0009] The centrifugation is carried out at 4000-6000 r / min for 10-15 min.

[0010] The prepared photocatalytic dual nanoenzyme gel dressing is used in products for treating wounds infected with bacteria.

[0011] The advantages of the present invention are:

[0012] 1. The iron-doped molybdenum selenide nanomaterial (Fe-MoSe 2 ), using the reducing property and photocatalytic activity of the liquid part with carbon dot characteristics, and the solid part with the properties of simulating peroxidase (POD) and superoxide dismutase (SOD), with antioxidant carbon dots as reducing agents, combined with the astringent and hemostatic white radix extract, antibacterial chitosan (CS) and polyethylene glycol (PEG) as the gel molecular skeleton, and the solid part Fe-MoSe 2 (Nanozyme) catalyzed oxidation of phenolic substances in Bletilla striata extract to prepare silver nanoparticles (AgNPs) gel dressing (Fe-MoSe 2 / AgNPs). Fe-MoSe with peroxidase activity 2 The low concentration of sodium persulfate is effectively converted into toxic hydroxyl radicals (·OH), which has a bactericidal effect. Under the action of near-infrared light (NIR), Fe-MoSe 2 / The POD and SOD activities of AgNPs are further enhanced, and the healing effect is very obvious for wounds that are seriously inflammatory due to bacteria and reactive oxygen free radicals, because antibacterial and antioxidant properties are important indicators of wound dressings;

[0013] 2. The present invention effectively combines natural product active substances with nanomaterials to prepare gel dressings for bacterially infected wounds, making full use of the antibacterial, antioxidant, astringent hemostatic and photocatalytic properties, while taking advantage of the gel's non-irritating, safe, non-toxic and non-side effect characteristics to promote wound healing and prevent wound infection;

[0014] 3. MoSe 2 / AgNPs materials have low toxicity, good biocompatibility and stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 TEM images of Fe, Mo, Se-CDs in Example 1;

[0016] Figure 2 is the Fe-MoSe in Example 1 2 TEM images of

[0017] Figure 3 is the Fe-MoSe in Example 1 2 TEM image of / AgNPs gel dressing;

[0018] Figure 4 Fe, Mo, Se-CDs, Fe-MoSe in Example 1 2 and Fe-MoSe 2 Zeta potential diagram of / AgNPs gel dressing;

[0019] Figure 5 Example 1 Fe-MoSe 2 UV-visible absorption spectra of TMB oxidized by AgNPs gel dressing (pseudo-POD) with or without NIR, where (1) is TMB alone, (2) TMB and Fe-MoSe 2 / AgNPs gel dressing has NIR radiation, (3) TMB and Fe-MoSe 2 / AgNPs gel dressing has no NIR radiation;

[0020] Figure 6 Example 1 Fe-MoSe 2 The inhibition rate and scavenging ability of photoreduction of nitro blue tetrazolium (NBT) by AgNPs gel dressing 2 ·- UV-visible absorption spectra of NBT with or without NIR (quasi-SOD), (1) NBT alone, (2) NBT and Fe-MoSe 2 / AgNPs gel dressing has NIR radiation, (3) NBT and Fe-MoSe 2 / AgNPs gel dressing has no NIR radiation;

[0021] Figure 7 Effect of EDTA on Fe-MoSe 2 / AgNPs gel dressing oxygen vacancy capture effect diagram, Blank in the figure is without adding Fe-MoSe 2 EDTA of / AgNPs gel dressing, +Fe-MoSe 2 / AgNPs gel dressing is EDTA-free;

[0022] Figure 8 The results of the cytotoxicity test of the nanoenzyme gel dressing in Example 1 are as follows;

[0023] Fig. 9 The results of the antibacterial test of nanoenzyme gel dressing in Example 1, the blank in the figure means no gel dressing;

[0024] Fig.10 This is a photograph of the wound healing of mice infected with bacteria treated with nanoenzyme gel dressings in Example 1;

[0025] Fig.11 This is Example 1. The healing rate of wounds in mice infected with bacteria treated with nanoenzyme gel dressing. Implementation

[0026] The technical solution of the present invention will be further described in detail below in conjunction with specific embodiments, but the protection scope of the present invention is not limited thereto.

[0027] Example 1: Preparation and performance of double nanoenzyme gel dressing

[0028] (1) Iron-doped molybdenum selenide nanomaterials (Fe-MoSe 2 ) Preparation: 0.4 g sodium selenate, 1.7 g L-cysteine, 0.2 g FeSO 4 7H 2 O was dissolved in 60 mL deionized water, ultrasonically treated for 15 min, and then transferred to a polytetrafluoroethylene tank, calcined in a muffle furnace at 200 °C for 20 h, centrifuged at 6000 r / min for 15 min, and filtered through a 0.22 μm filter membrane to obtain the supernatant, i.e., the liquid part (Fe, Mo, Se-CDs). The solid part was washed with 0.1 mol / L dilute sulfuric acid, anhydrous ethanol, and deionized water in turn, and dried in vacuum to obtain Fe-MoSe 2；

[0029] (2) Preparation of Bletilla striata extract: Pulverize the dried Bletilla striata and pass it through a 40-60 mesh sieve. Weigh 0.1 g of Bletilla striata powder and add 50 mL of 50% ethanol. Ultrasonicate at 50°C for 25 min and treat at 4000 r / min for 15 min. Take the supernatant and dry it in an oven at 70°C for 2 h to obtain Bletilla striata extract. Take 100 mg of Bletilla striata extract and dissolve it in 10 mL of deionized water to prepare 10 mg / mL Bletilla striata extract.

[0030] (3) Fe-MoSe 2 Preparation of / AgNPs gel dressing: 12% PEG400 solution was prepared with pure water, and 2.3 mg / mL AgNO3 solution and 0.005 mg / mL sodium persulfate solution were added, stirred for 40 min, and cooled to room temperature to prepare solution A; 0.2 mg / mL Fe, Mo, Se-CDs and 1 mg / mL Bletilla striata extract were mixed and stirred at a volume ratio of 1:10, and 0.2 mg / mL Fe-MoSe 2 Stir and disperse it into it to obtain liquid B; mix 5 parts by weight of liquid A and 1 part by weight of liquid B, stir for 30 minutes at room temperature and away from light to obtain liquid C; prepare 3% chitosan (CS) solution with 1% acetic acid, take 3% CS solution and liquid C in a volume ratio of 4:1 and mix and stir for 10 minutes to obtain Fe-MoSe 2 / AgNPs gel dressing. The conditions were exactly the same to prepare Fe, Mo, Se-CDs and Fe-MoSe 2 Gel dressings;

[0031] (4) TEM and Zeta potential test of nanomaterials: The synthesized Fe, Mo, Se-CDs, Fe-MoSe 2 and Fe-MoSe 2 / AgNPs gel dressing, freeze-dried and subjected to transmission electron microscopy (TEM) and Zeta potential tests ( Figure 1-4 ), from the TEM image ( Figure 1 ) shows that Fe, Mo, Se-CDs show good dispersion with an average size of 2.7 ± 0.7 nm and a quasi-spherical morphology. The lattice space is 0.21 nm, corresponding to the (100) crystal plane of graphite. 2 It is a nanosheet structure with uniform size, with an average size of 50 - 200 nm ( Figure 2 )。 );Fe-MoSe 2 / AgNPs gel dressing presents a highly porous structure ( Figure 3 ); Fe, Mo, Se-CDs and Fe-MoSe 2 The Zeta potential of Fe-MoSe 2 / AgNPs gel dressing is positive ( Figure 4 ), because the presence of CS makes the surface of the material positively charged, which is conducive to combining with the negatively charged cell membrane, changing the permeability of the cell membrane, and is beneficial to antibacterial;

[0032] (5) Determination of the pseudo-peroxidase (POD) activity of nanozymes using TMB colorimetric reaction

[0033] 100 µg / mL Fe-MoSe 2 / AgNPs gel dressing 100μL, 100mmol / L TMB 50μL, 40mmol / L H 2 O 2 50 µL was added to 2 mL of pH 5.0 acetate buffer solution and then filtered at 1.0 W / cm 2 After irradiation with 808 nm infrared light for 15 min, the samples were centrifuged at 4000 r / min for 10 min. The absorbance of the supernatant was measured at 654 nm using a UV-visible spectrophotometer. Each sample was measured 3 times and the average value was taken. The sample was set to have no absorption at 1.0 W / cm 2 The blank control was irradiated with 808 nm infrared light, and the absorption spectrum is shown in Figure 5 As can be seen from the figure, under the action of infrared light, Fe-MoSe 2 / AgNPs gel dressings had further enhanced peroxidase activity;

[0034] (6) Determination of pseudo-superoxide dismutase (SOD) activity by using nanozymes to inhibit the reaction of reduced nitro blue tetrazolium (NBT)

[0035] 100 µg / mL Fe-MoSe 2100 μL of / AgNPs gel dressing was mixed with 100 μL of 5 mg / mL NBT, 100 μL of 5 mg / mL riboflavin, and 2 mL of pH = 3 phosphate buffer and then heated at 1.0 W / cm 2 After irradiation with 808nm infrared light for 15min, the samples were centrifuged at 4000r / min for 10min. The supernatant was taken and the absorbance was measured at 580nm using a UV-visible spectrophotometer. Each sample was measured 3 times and the average value was taken. The sample that was not irradiated with 808nm infrared light was set as a blank control. The results are shown in the figure. Figure 6 ;from Figure 6 As can be seen from the figure, under the action of infrared light, Fe-MoSe 2 / AgNPs gel dressing showed quite high pseudo-SOD activity;

[0036] (7) EDTA was used as an oxygen vacancy scavenger. 100 µg / mL Fe-MoSe was added to 0.5, 1.0, and 5.0 μg / mL EDTA. 2 / AgNPs gel dressing 100μL, 10 mmol / L TMB 50µL, 40mmol / L H 2 O 2 50 μL, centrifuged at 4000 r / min for 15 min, and the supernatant was taken and the absorbance was measured at 654 nm using a UV-visible spectrophotometer. The results are shown in Figure 7 As the concentration of EDTA increases, the absorbance decreases, indicating that MoSe 2 / AgNPs gel dressings have oxygen vacancies, which can improve the adsorption and activation of surface oxygen, thereby promoting the oxidation of the substrate;

[0037] (8) Cytotoxicity test: CCK-8 cell viability kit was used to detect the cytotoxicity of nanozymes. In the specific experiment, human umbilical vein endothelial cells (HUVECs, Beina Chuanglian Biotechnology Co., Ltd.) were inoculated in 96-well plates and cultured for 24 h. 2 / AgNPs gel dressing (0, 5, 10, 20, 40, 80, 160 μg / mL, with Ag + The cells were incubated for 12, 24, and 36 h, respectively, and the cells were rinsed with PBS. CCK-8 solution was added to each well to a concentration of 10%, and the cells were incubated at 37°C. The absorbance was measured at 450 nm. CCK-8 analysis ( Figure 8 ) shows MoSe 2 / AgNPs gel dressing had no obvious toxicity to cells;

[0038] (9) MoSe 2 Antibacterial test of / AgNPs gel dressing

[0039] The following strains were obtained from Beina Chuanglian Biotechnology Co., Ltd.;

[0040] Experimental method: Methicillin-resistant Staphylococcus aureus (MRSA, ATCC 43300) and Escherichia coli ( E. coli , ATCC 25922) was used as the representative Gram-negative strain. The plate count method was used to determine the number of CFUs. 2 The antibacterial properties of / AgNPs gel dressings. First, the above-mentioned strains were incubated in solid Luria-Bertani (LB) medium and solid nutrient broth medium for 24 h, and a small amount of colonies formed were picked up with an inoculation loop and inoculated into the corresponding liquid culture medium (5 mL). Then, the bacterial suspension (1×10 8 CFU / mL), diluted to 1×10 5 CFU / mL. The materials were divided into four groups: blank control group, Fe, Mo, Se-CDs, Fe-MoSe 2 and Fe-MoSe 2 / AgNPs gel dressing group. The cultured bacteria were added to phosphate buffer as a blank control group, and the other groups were mixed with different gel dressings at a concentration of 50 μg / mL and were exposed to 1.0 W / cm 2 After irradiation with 808 nm infrared light for 10 min and without infrared light treatment, the suspension was incubated at 37°C for 60 min. The diluted bacterial suspension (100 μL) was evenly spread on LB solid medium and nutrient broth solid medium and cultured at 37°C for 24 h. The number of colonies was calculated to determine the antibacterial properties.

[0041] The results are as follows Fig. 9 As shown in the figure, the blank control group had almost no antibacterial activity, and Fe, Mo, Se-CDs and Fe-MoSe were not irradiated with infrared light. 2 and Fe-MoSe 2 / AgNPs gel dressing group, MRSA and E. coli The antibacterial rates of Fe, Mo, Se-CDs, Fe-MoSe and 2 and Fe-MoSe 2 / AgNPs gel dressing group against MRSA and E. coliThe antibacterial rates of Fe-MoSe 2 / AgNPs gel dressings were irradiated with infrared light to treat MRSA and E. coli It has a sterilization rate of nearly 100%;

[0042] (10) Mouse wound healing test

[0043] Mouse back wound model: All animal experiments were conducted in accordance with the Animal Care Guidelines. Male ICR mice aged 6 to 8 weeks and weighing 18 to 20 g were selected as experimental animals. A circular surgical wound with a diameter of 1 cm was made on the back of the mice anesthetized with ether using medical scissors. Then, 100 μL of MRSA or E. coli Bacterial suspension (1×10 8 CFU / mL) was evenly applied to the wound surface and bandaged with gauze and medical tape. 24 hours after the mice were infected with bacteria, they were randomly divided into 4 groups (5 mice in each group): control group, Fe, Mo, Se-CDs gel dressing, Fe-MoSe 2 Gel dressing and Fe-MoSe 2 / AgNPs gel dressings, and the control was smeared with sterile PBS. The concentration of the remaining gels was 50 μg / mL. The above gels (300 μL each) were injected into the wounds of mice and then illuminated at 1.0 W / cm 2 Irradiate with 808nm infrared light for 15min; replace the hydrogel in the mouse wound every 24h, and measure the wound condition of the mouse on days 0, 2, 4, 6, and 8. The healing rate (%) = (A 0 - A t ) / (A 0 ×100) to calculate the wound healing rate, where A 0 is the initial wound area, A t is the residual wound area at each time point;

[0044] The results showed that pus appeared on the first day in the PBS treatment group and lasted until the eighth day, indicating wound infection. 2 The wound area of ​​the / AgNPs gel dressing group was significantly reduced to 8.31% (healing rate was 91.69%), which was the lowest among the other treatment groups, and the wound was basically healed, while the wound of the control group did not heal, with a wound area of ​​90.15% (healing rate was 9.85%) ( Fig.10 , Fig.11 ).

[0045] The above results show that the nanozyme Fe-MoSe prepared by the present invention 2 / AgNPs gel dressing has dual enzyme activity, which can play an antibacterial role by simulating POD activity through nanozymes, and an antioxidant and astringent effect by pomegranate peel water extract, as well as an anti-inflammatory effect by scavenging free radicals by simulating SOD activity through nanozymes, thus achieving a good healing effect on the wounds of bacterially infected mice.

Claims

1. A photocatalytic dual nanoenzyme gel dressing for wound healing, characterized in that: The preparation steps are as follows: (1) Preparation of iron-doped molybdenum selenide nanomaterial (Fe-MoSe2): 0.3-0.5 g sodium selenate, 1.5-2.0 g L-cysteine, and 0.1-0.2 g FeSO4·7H2O were dissolved in 50-80 mL deionized water, and after ultrasonic treatment for 10-15 min, the mixture was transferred to a polytetrafluoroethylene tank, calcined in a muffle furnace at 200-220° C. for 18-24 h, centrifuged, and filtered through a 0.22 μm filter membrane to obtain a supernatant, i.e., the liquid portion of the iron-doped molybdenum selenide nanomaterial, i.e., Fe, Mo, Se-CDs, and the solid portion was washed with 0.1 mol / L dilute sulfuric acid, anhydrous ethanol, and deionized water in sequence, and dried in vacuo to obtain the iron-doped molybdenum selenide nanomaterial, i.e., Fe-MoSe2; (2) Preparation of Fe-MoSe2 / AgNPs gel dressing: Add AgNO3 solution and sodium persulfate solution to polyethylene glycol 400 aqueous solution, stir for 40 min, and cool to room temperature to prepare solution A; mix Fe, Mo, Se-CDs and Bletilla striata extract at a volume ratio of 1:10, and stir and disperse Fe-MoSe2 therein. as liquid B; 5 parts by weight of liquid A and 1 part by weight of liquid B are mixed, stirred for 30 minutes at room temperature away from light to obtain liquid C; chitosan CS solution is prepared with 1% acetic acid, CS solution and liquid C are mixed and stirred at a volume ratio of 4:1 for 10 minutes to obtain Fe-MoSe2 / AgNPs gel dressing, and Fe, Mo, Se-CDs and Fe-MoSe2 gel dressings are prepared under exactly the same conditions, wherein the concentration of Bletilla striata extract is 2-3 mg / mL, the concentration of polyethylene glycol 400 is 10-12% (w / v), the concentration of AgNO3 solution is 2-3 mg / mL, the concentration of sodium persulfate solution is 0.001-0.005 mg / mL, the concentration of CS is 2-3% (w / v), the concentration of Fe, Mo, Se-CDs is 0.1-0.3 mg / mL, and the concentration of Fe-MoSe2 is 0.1-0.5 mg / mL.

2. The photocatalytic dual nanoenzyme gel dressing for wound healing according to claim 1, characterized in that: The Bletilla striata extract is prepared according to the following method: the dried Bletilla striata is crushed, passed through a 40-60 mesh sieve, 0.1-0.2 g of Bletilla striata powder is weighed, 800-100 mL of 40%-50% ethanol is added, ultrasonicated at 50° C. for 25-30 min, centrifuged, the supernatant is taken, and dried in an oven at 60-70° C. for 1-2 h to obtain the Bletilla striata extract, which is prepared with pure water to the required concentration as required.

3. The photocatalytic dual nanoenzyme gel dressing for wound healing according to claim 1, characterized in that: The centrifugation was carried out at 4000-6000 r / min for 10-15 min.

4. The use of the photocatalytic dual nanoenzyme gel dressing according to claim 1 is used in the preparation of anti-bacterial infection wound products.

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