Injectable silk fibroin / zinc oxide / magnetic mica sheet nanoscale enzyme hydrogel, preparation method and application thereof

Abstract

The present application relates to the technical field of functional materials, in particular to an injectable silk fibroin / zinc oxide / magnetic mica sheet nano-enzyme hydrogel, a preparation method and application thereof, after the prepared silk fibroin aqueous solution, nano-zinc oxide and magnetic mica sheet are uniformly mixed, the pH value is adjusted, and physical gelation is carried out through simple ultrasonic crushing, so that the injectable nano-enzyme hydrogel can be obtained. The preparation method is simple, controllable, the prepared nano-enzyme hydrogel has good injection performance and biocompatibility, and based on the nano-enzyme strategy, the in-situ self-produced hydrogen peroxide can be catalyzed into active oxygen without relying on stimuli such as light, so that the synergistic antibacterial ability and the ability to promote wound tissue healing are significantly improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of functional materials, in particular to an injectable silk fibroin / zinc oxide / magnetic mica sheet nanoscale enzyme hydrogel, a preparation method and application thereof. BACKGROUND

[0002] The artificial synthetic peroxidase-like nanoscale enzyme based on nanomaterials is a typical nanoscale enzyme, which can catalyze the conversion of hydrogen peroxide in a physiological environment into active oxygen, and further kill pathogens. In order to achieve satisfactory therapeutic effect, the supply of hydrogen peroxide is one of the key factors to determine the generation of active oxygen. Therefore, materials with peroxidase properties can be applied in environments rich in hydrogen peroxide, such as tumor tissues. In addition, exogenous hydrogen peroxide can also be directly provided, for example, in skin wounds, to eliminate bacterial infection in the wound by catalyzing the generation of active oxygen.

[0003] The nanoscale enzyme strategy can avoid the short life of free radicals by catalyzing the generation of active oxygen in situ, while improving the treatment efficiency of the target and showing biocompatibility to healthy tissues due to the absence of hydrogen peroxide. However, in some cases, the concentration of hydrogen peroxide in tumors is insufficient, and liquid hydrogen peroxide sprayed on skin wounds may leak during human movement. Therefore, more and more people combine self-supplying hydrogen peroxide agents with peroxidase-like nanoscale enzymes to provide sufficient hydrogen peroxide in situ to achieve stable therapeutic effect. However, most of the treatment processes that rely on light stimulation and other forms are poor in darkness or ambient light. Therefore, drugs that do not rely on external stimulation to spontaneously generate hydrogen peroxide are of great significance for catalyzing the generation of active oxygen. SUMMARY

[0004] The present application aims to solve the problem of how to combine zinc oxide and silk fibroin hydrogel to face the challenge of the increasing emergence of drug-resistant bacteria and the damage of antibacterial agents to human tissues, and to provide an injectable silk fibroin / zinc oxide / magnetic mica sheet nanoscale enzyme hydrogel, a preparation method and application thereof.

[0005] In order to achieve the above-mentioned purpose, the present application discloses a preparation method of an injectable silk fibroin / zinc oxide / magnetic mica sheet nanoscale enzyme hydrogel, comprising the following steps:

[0006] S1: uniformly mix silk fibroin aqueous solution, zinc oxide aqueous solution treated by air and hydrogen, and magnetic mica sheet aqueous solution, and adjust the pH value;

[0007] S2: obtain the injectable silk fibroin / zinc oxide / magnetic mica sheet nanoscale enzyme hydrogel by ultrasonic crushing of the mixed solution after adjusting the pH value in step S1.

[0008] The treatment process of zinc oxide in step S1 is as follows: after drying, the zinc oxide is cooled to room temperature, calcined in a hydrogen atmosphere, and then isothermally annealed and cooled to room temperature to obtain the zinc oxide treated by air and hydrogen.

[0009] The drying temperature is 180 DEG C, the drying time is 5h, the calcination temperature is 600 DEG C, the heating rate is 3 DEG C / min, and the isothermal annealing time is 0.5h.

[0010] The preparation step of the magnetic mica sheet aqueous solution in step S1 is as follows:

[0011] S11: The ethanol dispersion containing exfoliated mica sheets and iron acetylacetone are added into the triethylene glycol and mixed, heated and stirred under a nitrogen atmosphere, and incubated;

[0012] S12: After the reaction in step S11 is completed, the mixture is cooled to room temperature, diluted with anhydrous ethanol, and centrifuged to obtain the magnetic mica sheet aqueous solution.

[0013] The amount ratio of the ethanol dispersion containing exfoliated mica sheets, iron acetylacetone and triethylene glycol in step S11 is 100mg:100mg:50mL, the stirring and heating time is 1.5h, the stirring and heating temperature is 300 DEG C, the incubation temperature is 300 DEG C, and the incubation time is 30min.

[0014] In step S12, the centrifugation is first performed after dilution with anhydrous ethanol, the rotation speed is 5000r / min, and the centrifugation is repeated three times, followed by centrifugation in deionized water three times at a rotation speed of 5000r / min.

[0015] The adjusted pH value in step S1 is 5.

[0016] The power of the ultrasonic crushing in step S2 is 40%, and the time is 5min.

[0017] The application also discloses an injectable silk fibroin / zinc oxide / magnetic mica sheet nanoscale enzyme hydrogel prepared by the preparation method and application of the injectable silk fibroin / zinc oxide / magnetic mica sheet nanoscale enzyme hydrogel in antibacterial and promotion of wound tissue repair and healing after bacterial infection.

[0018] Compared with the prior art, the application has the following beneficial effects:

[0019] 1. The application can be physically prepared into glue by simple ultrasonic crushing, and has better injectability and biological safety compared with other chemically gelled hydrogels;

[0020] 2. The nano zinc oxide used in the application has a significantly improved ability to produce hydrogen peroxide under lightless conditions after further treatment;

[0021] 3、The magnetic mica sheet nanoenzyme used in the application has a significantly improved ability to produce reactive oxygen in situ through further optimization;

[0022] 4、The application improves the antibacterial ability of the hydrogel by adding magnetic mica sheet nanoenzyme to the hydrogel containing zinc oxide. The nano zinc oxide itself can kill bacteria, and the addition of magnetic mica sheet nanoenzyme can achieve the ability to catalyze hydrogen peroxide to reactive oxygen in situ without relying on stimuli such as light, and further optimize the ratio to achieve more significant and effective synergistic antibacterial ability, which has important significance for clinical application;

[0023] 5、The injectable nanoenzyme hydrogel prepared in the application can be used for wound infection tissue repair and healing, and has a significantly improved antibacterial ability and a wound infection healing promoting ability. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 Transmission electron microscopy (TEM) photos of the magnetic mica sheets synthesized in Example 1;

[0025] Figure 2 Scanning electron microscopy (SEM) photos of the magnetic mica sheets synthesized in Example 1;

[0026] Figure 3 Size data photos of the magnetic mica sheets synthesized in Example 1;

[0027] Figure 4 Ultraviolet data photos of various nanoenzymes synthesized in Example 1 after TMB coloration in hydrogen peroxide;

[0028] Figure 5 High-magnification transmission electron microscopy (TEM) photos of zinc oxide treated by air and hydrogen in Example 2;

[0029] Figure 6 TMB coloration photos of zinc oxide treated by different methods in Example 3. From left to right are zinc oxide plus magnetic mica sheets, zinc oxide plus TMB, zinc oxide obtained by calcining synthesized ZIF-8 (all groups above and below are added with magnetic mica sheets and TMB), DEG zinc oxide, zinc oxide, zinc oxide treated in air, zinc oxide treated in hydrogen atmosphere, and zinc oxide treated in air and hydrogen atmosphere in sequence;

[0030] Figure 7 Ultraviolet data photos of zinc oxide treated by different methods in Example 3 after TMB coloration;

[0031] Figure 8 Scanning electron microscopy (SEM) photos of the nanoenzyme hydrogel synthesized in Example 5;

[0032] Figure 9 EDS data photo of nanoscale enzyme hydrogel synthesized for Example 5;

[0033] Figure 10 XPS data photo of nanoscale enzyme hydrogel synthesized for Example 5;

[0034] Figure 11 Underwater injection real data photo of nanoscale enzyme hydrogel synthesized for Example 5;

[0035] Figure 12 Injection force size data photo of nanoscale enzyme hydrogel synthesized for Example 5;

[0036] Figure 13 Bacteriostatic circle data photo of silk protein / zinc oxide / magnetic mica sheet nanoscale enzyme hydrogel and silk protein / zinc oxide hydrogel (zinc oxide was not treated in any way);

[0037] Figure 14 Bacteriostatic circle data photo of silk protein / zinc oxide / magnetic mica sheet nanoscale enzyme hydrogel and silk protein / zinc oxide hydrogel (zinc oxide was treated in air and hydrogen atmosphere in turn);

[0038] Figure 15 Wound healing data photo of rats with no treatment, treated with silk protein / zinc oxide hydrogel and treated with silk protein / zinc oxide / magnetic mica sheet nanoscale enzyme hydrogel. DETAILED DESCRIPTION

[0039] The above and other technical features and advantages of the present application will be more apparent from the following detailed description taken in conjunction with the accompanying drawings.

[0040] Example 1

[0041] Preparation of magnetic mica sheet nanoscale enzyme

[0042] (1) First, natural sericite powder is calcined, acidified, sodiumized and hexadecyl trimethyl ammonium bromide (CTAB) intercalated, and then ultrasonic broken and peeled to obtain single-layer and few-layer mica sheets, with an ultrasonic breaking power of 50% and a time of 45 min. The peeled mica sheets are centrifuged and collected, and finally dispersed in an ethanol solution to obtain single-layer or few-layer mica sheets with a certain concentration;

[0043] (2) In a three-necked flask with 50 mL of triethylene glycol, add 100 mg of ethanol dispersion containing exfoliated mica sheet and 100 mg of acetylacetone iron, vacuumize and then introduce nitrogen, under the condition of magnetic stirring, heat from room temperature to 300 degrees Celsius, time is 1.5 h, then keep at 300 degrees Celsius for 30 min. After cooling to room temperature, add anhydrous ethanol for dilution and centrifugal collection, speed is 5000 r / min, repeat centrifugation three times, then disperse in deionized water and centrifugal three times, speed is 5000 r / min. Finally, a magnetic mica sheet aqueous solution with certain concentration is obtained.

[0044] Figure 1 The transmission electron microscope photo of the magnetic mica sheet synthesized in this embodiment, from the figure, it can be seen that the single-layer magnetic mica sheet synthesized in this embodiment is uniformly covered with iron oxide nanoparticles.

[0045] Figure 2 The scanning electron microscope photo of the magnetic mica sheet synthesized in this embodiment, from the figure, it can be seen that the magnetic mica sheet synthesized in this embodiment has relatively uniform size.

[0046] Figure 3 The Size photo of the magnetic mica sheet synthesized in this embodiment, from the figure, it can be seen that the average particle size of the magnetic mica sheet synthesized in this embodiment is about 700 nm.

[0047] Optimization of catalytic performance of magnetic mica sheet nanoscale enzyme

[0048] (1) We determine 100 mg of exfoliated mica sheet, by adding 50, 100, 200 mg of acetylacetone iron in 50 mL of triethylene glycol, i.e. the ratio is 2:1, 1:1, 1:2, to optimize the best catalytic capacity of the final magnetic mica sheet. First, prepare a 0.5 mg / mL aqueous solution of zinc oxide treated by air and hydrogen, after 24 h of dark stirring, centrifugal collect the supernatant, speed is 12000 / min, time is 6 min. Then mix the supernatant, TMB color reagent and magnetic mica sheet uniformly, and adjust the PH value to about 5.0. The concentration of TMB in the final mixture is 5 mM / mL, and the iron content concentration of the magnetic mica sheet is 30 μg / mL. When the color is the darkest, detect the absorbance of the final solution at 650 nm by ultraviolet-visible spectrophotometer, and set a control group, i.e. add 100 mg of acetylacetone iron in 50 mL of triethylene glycol to synthesize iron oxide nanoscale enzyme without adding exfoliated mica sheet, to perform TMB coloration in hydrogen peroxide, and add TMB for coloration in hydrogen peroxide in the control group.

[0049] (2) Data processing

[0050] Figure 4The UV spectrum after the TMB color development experiment of Example 1 can be seen that hydrogen peroxide alone cannot make TMB color development, only after adding magnetic mica sheet nanoscale enzyme or ferroferric oxide nanoscale enzyme will color development have UV absorption peak, and the magnetic mica sheet nanoscale enzyme prepared by peeling the mica sheet in the ratio of acetylacetone iron = 1:1 has better catalytic effect, and the catalytic effect of the magnetic mica sheet nanoscale enzyme is better than that of the ferroferric oxide nanoscale particles, so the magnetic mica sheet nanoscale enzyme with this ratio is used later.

[0051] Example 2

[0052] Secondary treatment of zinc oxide

[0053] (1) The zinc oxide purchased from Sinopharm was placed in an oven at 180°C for 5h, and then cooled to room temperature;

[0054] (2) Then calcined in a quartz tube furnace under a hydrogen atmosphere, the temperature was 600°C, the heating rate was 3°C / min, and the isothermal annealing time was 0.5h, then the zinc oxide powder was cooled to room temperature in the quartz tube. Finally, the air and hydrogen treated zinc oxide was obtained.

[0055] Figure 5 The high-resolution transmission electron microscopy (TEM) photograph of the zinc oxide further treated in Example 2 can be seen that the nano-zinc oxide is still spherical or elliptical, with a particle size of about 50nm, and the structure of the nano-zinc oxide has not changed.

[0056] Example 3

[0057] This experimental example was operated according to the following steps

[0058] (1) First, prepare different zinc oxides: zinc oxide without any treatment, oven treated ZnO, hydrogen atmosphere treated ZnO in a quartz tube furnace, and zinc oxide treated by both.

[0059] (2) We prepared different zinc oxides into 0.5mg / mL aqueous solution, stirred in the dark for 5h, then centrifuged to collect the supernatant at a speed of 12000 / min for 6min;

[0060] (3) Mix the supernatant with TMB color developing reagent and magnetic mica sheet evenly, and adjust the pH value to about 5.0. The concentration of TMB in the final mixture is 5mM / mL, and the iron content concentration of the magnetic mica sheet is 30μg / mL. Detect the absorbance of the final solution at 650nm with ultraviolet-visible spectrophotometer when the color is the darkest;

[0061] (4) Data processing.

[0062] Figure 6The TMB color developing real photos of zinc oxide after further processing in Example 3; the color deepens from left to right, representing the ability of various zinc oxide to produce reactive oxygen after catalysis by magnetic mica sheet nanometer enzyme. And from left to right are zinc oxide plus magnetic mica sheet, zinc oxide plus TMB (except for the above several groups, this group and the following groups all add magnetic mica sheet and TMB), zinc oxide, zinc oxide treated in air, zinc oxide treated in hydrogen atmosphere, zinc oxide treated in air and hydrogen atmosphere. It can be seen that in the absence of TMB, although there are magnetic mica sheets in the supernatant of zinc oxide, no color can be developed. The control group without magnetic mica sheets in the supernatant of zinc oxide can hardly react with TMB to develop color. It can also be seen that color can only be developed when both magnetic mica sheets and TMB are present in the supernatant of zinc oxide, and the effect is significantly improved, indicating that reactive oxygen species are generated in situ under the action of magnetic mica sheets and react with TMB to develop color. The zinc oxide treated in air and hydrogen atmosphere has the strongest ability, and the color after TMB development is the deepest. Therefore, the zinc oxide treated in air and hydrogen atmosphere is also used in some applications later.

[0063] Figure 7 The UV data photos of zinc oxide after TMB color development after further processing in Example 3, Figure 6 The color change of Figure 7 Corresponding, from top to bottom are zinc oxide plus magnetic mica sheet, zinc oxide plus TMB (except for the above several groups, this group and the following groups all add magnetic mica sheet and TMB), zinc oxide, zinc oxide treated in air, zinc oxide treated in hydrogen atmosphere, zinc oxide treated in air and hydrogen atmosphere. It can be seen that in the absence of TMB, although there are magnetic mica sheets in the supernatant of zinc oxide, no color can be developed. The control group without magnetic mica sheets in the supernatant of zinc oxide can hardly react with TMB to develop color, and the peak value is almost zero. It can also be seen that color can only be developed when both magnetic mica sheets and TMB are present in the supernatant of zinc oxide, and the effect is significantly improved, the peak value is significantly improved, indicating that reactive oxygen species are generated in situ under the action of magnetic mica sheets and react with TMB to develop color. It can be seen that the zinc oxide treated in air and hydrogen atmosphere has the highest UV absorption peak, indicating that the ability to produce reactive oxygen in situ after catalysis by magnetic mica sheet nanometer enzyme is the strongest, so the zinc oxide treated in air and hydrogen atmosphere is also used in some applications later.

[0064] Example 4

[0065] Preparation of silk protein aqueous solution

[0066] To prepare the aqueous silk fibroin solution, the cut cocoon was boiled in 0.02M aqueous sodium carbonate solution for 30min, then washed with plenty of deionized water and dried. Then the degummed silk fiber was dissolved in 9.3M lithium bromide solution at 60℃ for 4h. The aqueous silk fibroin solution was obtained after dialysis for 72h, with a final concentration of about 6%.

[0067] Example 5

[0068] A method for preparing an injectable silk fibroin / zinc oxide / magnetic mica sheet nanoscale enzyme hydrogel

[0069] (1) The aqueous silk fibroin solution, 1.0mg / mL zinc oxide solution treated by oxygen and hydrogen, and 0.4mg / mL magnetic mica sheet solution with iron content were mixed uniformly and the pH value was adjusted to about 5. In the mixed solution, in order to further optimize the injection performance of the hydrogel, the injection force was compared when the concentration of silk fibroin was 20, 30, 40, and 50mg / mL;

[0070] (2) The mixed solution after adjusting the pH value can obtain the injectable silk fibroin / zinc oxide / magnetic mica sheet nanoscale enzyme hydrogel by ultrasonic crushing method. The power of crushing is 40% and the time is 5min;

[0071] Figure 8 The scanning electron microscope (SEM) photo of the nanoscale enzyme hydrogel synthesized in Example 5 can be seen that the nanoscale enzyme hydrogel has a good three-dimensional pore structure.

[0072] Figure 9 The EDS data photo of the nanoscale enzyme hydrogel synthesized in Example 5 can be seen that the hydrogel uniformly contains elements such as zinc and iron.

[0073] Figure 10 The XPS data photo of the nanoscale enzyme hydrogel synthesized in Example 5 can be seen that, corresponding to Figure 8 , the hydrogel contains zinc oxide and magnetic mica sheet.

[0074] Figure 11 The underwater injection real data photo of the nanoscale enzyme hydrogel synthesized in Example 5 with silk fibroin concentration of 30mg / mL can be seen that it has good injectability.

[0075] Figure 12The injection force data chart of the nanoscale enzyme hydrogel of different silk fibroin concentrations synthesized in Example 5 can be seen that when the silk fibroin concentration is 30 mg / mL, the injection force is only about 5 N, which is easy to inject, and when the silk fibroin concentration is 40 and 50 mg / mL, the injection force increases significantly, and the spectrum chart shakes violently, which is due to the too large gel concentration, it is difficult to inject, and when the silk fibroin concentration is 20 mg / mL, although the injection force is also small, there is also a significant fluctuation, which is due to the low concentration leading to the difficulty of gelation, even if the gelation is not uniform and insufficient, so the silk fibroin concentration of 30 mg / mL is selected.

[0076] Nanoscale enzyme hydrogel antibacterial inhibition zone experiment

[0077] (1) The silk fibroin / zinc oxide / magnetic mica sheet nanoscale enzyme hydrogel synthesized in Example 5 was injected on the culture plate containing 10 5 CFU / mL of Staphylococcus aureus solution by using the plate coating method, and cultured at 37°C for 24 h, and then the size of the inhibition zone was observed. The zinc oxide used here was treated by air and hydrogen, and we also conducted an experiment on zinc oxide without any treatment according to the above operation;

[0078] (2) Data processing.

[0079] Figure 13 The inhibition zone data photo of the nanoscale enzyme hydrogel synthesized in Example 5 using zinc oxide without any treatment can be seen that the silk fibroin / zinc oxide / magnetic mica sheet nanoscale enzyme hydrogel using zinc oxide without any treatment has a certain improvement in antibacterial ability compared with the silk fibroin / zinc oxide hydrogel group due to the presence of magnetic mica sheet nanoscale enzyme, and the antibacterial ability improves with the increase of zinc oxide concentration, but when the zinc oxide concentration is 0.1 mg / mL, the inhibition zone is almost none whether the magnetic mica sheet is added or not, and the antibacterial ability is almost none.

[0080] Figure 14 The inhibition zone data photo of the nanoscale enzyme hydrogel synthesized in Example 5 using zinc oxide treated by air and hydrogen can be seen that the silk fibroin / zinc oxide / magnetic mica sheet nanoscale enzyme hydrogel using zinc oxide treated by air and hydrogen has a more significant improvement in antibacterial ability compared with the silk fibroin / zinc oxide hydrogel group, and surprisingly, when the zinc oxide concentration is 0.1 mg / mL, an unexpected result appears compared with the group adding zinc oxide without any treatment, that is, the inhibition zone appears, and it is more obvious, and the antibacterial ability improves more significantly and more stably with the increase of zinc oxide concentration, which is also very important in actual clinical application.

[0081] Nanoscale enzyme hydrogel rat wound healing experiment

[0082] (1) To evaluate the promotion of silk protein / zinc oxide / magnetic mica sheet nanozyme hydrogel on wound healing after MRSA infection, MRSA-infected skin models were established and compared with silk protein / zinc oxide hydrogel and blank treatment group. Wounds were created on the shaved back of rats, incubated with MRSA, and the concentration of bacteria was 10 7 CFU / mL. Then the wounds were not treated, treated with silk protein / zinc oxide hydrogel and treated with silk protein / zinc oxide / magnetic mica sheet nanozyme hydrogel;

[0083] (2) Data processing.

[0084] Figure 15 For the wound healing data photos of rats not treated, treated with silk protein / zinc oxide hydrogel and treated with silk protein / zinc oxide / magnetic mica sheet nanozyme hydrogel, it can be seen that the silk protein / zinc oxide / magnetic mica sheet nanozyme hydrogel has completely healed the wound at 12 days compared with the blank control group and the silk protein / zinc oxide hydrogel control group. It can be seen that the nanozyme hydrogel prepared by us has a significantly enhanced ability to promote wound healing, and also reflects a more significant and effective synergistic antibacterial effect, which is very meaningful in clinical application.

[0085] The above only describes the preferred embodiments of the present application, which are only illustrative but not limiting. Those skilled in the art understand that many changes, modifications and even equivalents can be made to the present application within the spirit and scope defined by the claims of the present application, but all will fall within the protection scope of the present application.

Claims

1. A method for preparing injectable silk fibroin / zinc oxide / magnetic mica flake nanozyme hydrogel, characterized in that, The preparation method comprises the following steps: S1: mixing silk fibroin aqueous solution, air and hydrogen treated zinc oxide aqueous solution, and magnetic mica sheet aqueous solution, and adjusting pH value; S2: obtaining injectable silk fibroin / zinc oxide / magnetic mica sheet nanoenzyme hydrogel by ultrasonic crushing of the mixed solution after adjusting pH value in step S1; The treatment process of zinc oxide in step S1 is as follows: drying zinc oxide, cooling to room temperature, calcining in hydrogen atmosphere, isothermal annealing, and cooling to room temperature to obtain air and hydrogen treated zinc oxide; the drying temperature is 180℃, the drying time is 5h, the calcining temperature is 600℃, the heating rate is 3℃ / min, and the isothermal annealing time is 0.5h; The preparation steps of the magnetic mica sheet aqueous solution in step S1 are as follows: S11: adding ethanol dispersion liquid containing exfoliated mica sheet and acetylacetone iron into triethylene glycol, heating and stirring under nitrogen atmosphere, and keeping warm reaction; S12: cooling to room temperature after the reaction in step S11 is completed, diluting by adding anhydrous ethanol, and centrifuging to collect, at a speed of 5000r / min; repeating centrifugation three times, dispersing in deionized water, and centrifuging three times at a speed of 5000r / min to obtain magnetic mica sheet aqueous solution; The amount ratio of exfoliated mica sheet, acetylacetone iron and triethylene glycol in step S11 is 100mg:100mg:50mL, the stirring and heating time is 1.5h, the heating and stirring temperature is 300℃, the keeping warm temperature is 300℃, and the keeping warm time is 30min.

2. A method of preparing an injectable silk fibroin / zinc oxide / magnetic mica plate nanozyme hydrogel according to claim 1, characterized in that, The adjusted pH value in step S1 is 5, the concentration of silk fibroin in the mixed solution obtained in step S1 is 30mg / mL, the concentration of iron in the magnetic mica sheet aqueous solution is 0.4mg / mL, and the concentration of zinc oxide in the zinc oxide aqueous solution is 0.1-1.0mg / mL.

3. A method of preparing an injectable silk fibroin / zinc oxide / magnetic mica plate nanozyme hydrogel according to claim 1, characterized in that, The power of ultrasonic crushing in step S2 is 40%, and the time is 5min. 4.An injectable silk fibroin / zinc oxide / magnetic mica sheet nanoenzyme hydrogel prepared by the preparation method in any one of claims 1-3. 5.Use of the injectable silk fibroin / zinc oxide / magnetic mica sheet nanoenzyme hydrogel in claim 4 in preparation of a medicine for resisting bacteria and promoting repair and healing of wound tissue after bacterial infection.

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