A wearable magnesium battery self-powered dressing for chronic wound healing and its preparation method and application

Abstract

The present application belongs to the technical field of battery dressing, and particularly relates to a wearable magnesium battery self-powered dressing for chronic wound healing and a preparation method and application thereof. A flexible conductive carbon cloth coated with a viologen-based covalent organic framework material is used as a positive electrode of a battery, a magnesium sheet is used as a negative electrode, and a polyacrylamide hydrogel is used as a solid-state electrolyte, so that a flexible wearable self-powered dressing is assembled. The formed electrode can effectively input electric stimulation to a wound surface, the dressing can simulate an endogenous electric field in the wound, induce migration of fibroblasts, regulate a wound immune microenvironment, inhibit an inflammatory response, and the polyacrylamide gel electrolyte has good hygroscopicity, can absorb exudate at the wound surface, maintain a moist healing environment, and effectively promote chronic wound healing of rats. The self-powered dressing prepared by the present application provides a reliable electrotherapy method for chronic wound healing.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of battery dressings, and particularly relates to a wearable magnesium battery self-powered dressing for chronic wound healing and a preparation method and application thereof. BACKGROUND

[0002] Skin tissue is the first important protective barrier of the human body, which isolates the internal environment of the human body from the external environment. When the skin is damaged, the protection ability of the human body will be weakened. Among them, chronic wounds typified by diabetic wounds are a major challenge in clinical wound treatment. The high sugar environment of the wound is often accompanied by serious bacterial infection, excessive inflammation and other problems, leading to slow wound healing, and improper treatment can even cause serious adverse symptoms such as wound ulcer and sepsis.

[0003] At present, the main methods for treating diabetic wounds are to remove necrotic tissue, negative pressure wound therapy, hyperbaric oxygen therapy, and local medication. The widely used traditional dressing focuses on removing microorganisms on the wound surface to relieve wound inflammation, and this process hardly involves the regulation of endogenous cells. The appearance of the wound is accompanied by an electric field formed from the surrounding intact tissue to the center of the wound. Based on the principle of skin cell electrotaxis, exogenous electric stimulation treatment can effectively regulate the behavior of cells at the wound surface and accelerate the repair of the skin. However, the traditional electric stimulation device is bulky, and its portability is greatly limited. However, the lightness and service life of the power supply of the current wearable device need to be improved, which limits the application scenarios of electric stimulation.

[0004] The flexible bioelectronic medical device inspired by the skin has the advantages of softness, wearability, non-invasiveness, etc., and can perfectly fit the skin surface and be more flexibly applied to various biological interfaces. Magnesium metal has the characteristics of abundant source, safety, and biodegradability, so the magnesium metal battery can be used as an ideal wearable functional device. The skin epidermis is exposed to an oxygen-rich environment, and the magnesium battery can autonomously generate oxygen self-charging, which shows excellent application potential on wearable functional devices. Flexible carbon cloth is often used as a cathode counter electrode, but it lacks antibacterial properties. An antibacterial coating is designed on the surface of the electrode to improve the antibacterial properties of the electrode, and the electrode can effectively combine with electric stimulation to further promote the removal of bacteria from the wound surface. At the same time, the hydrogel electrolyte effectively absorbs wound tissue exudate, providing a moist healing environment for the wound surface. So far, there are few related studies on self-powered wound patches based on magnesium batteries. SUMMARY

[0005] In view of the above problems, the purpose of the present application is to provide a wearable magnesium battery self-powered dressing for chronic wound healing and a preparation method and application thereof.

[0006] The technical content of the present application is as follows:

[0007] The application provides a wearable magnesium battery self-powered dressing for chronic wound healing, which is a flexible wearable self-powered dressing obtained by assembling a flexible conductive carbon cloth coated with a viologen-based covalent organic framework material TVCOF@CNT as a positive electrode of a battery, a magnesium sheet as a negative electrode, and a solid-state electrolyte connecting the resistance and the carbon cloth and the magnesium sheet to form a closed loop.

[0008] The viologen-based covalent organic framework material is prepared by adding a tri-aldehyde-based phloroglucinol, 1,1'-bis(4-aminophenyl)-[4,4'-bipyridine]-1,1'-dichloroammonium and carbon nanotubes into an organic solvent, uniformly mixing by ultrasonic, adding a reaction catalyst and uniformly mixing by ultrasonic again, and preparing the viologen-based covalent organic framework material TVCOF@CNT by reaction at room temperature.

[0009] The mass ratio of the tri-aldehyde-based phloroglucinol to the 1,1'-bis(4-aminophenyl)-[4,4'-bipyridine]-1,1'-dichloroammonium is 1:(2-4).

[0010] The mass ratio of the mixture of the tri-aldehyde-based phloroglucinol and the 1,1'-bis(4-aminophenyl)-[4,4'-bipyridine]-1,1'-dichloroammonium to the carbon nanotubes is (3-5):1.

[0011] The solid-liquid ratio of the tri-aldehyde-based phloroglucinol, the 1,1'-bis(4-aminophenyl)-[4,4'-bipyridine]-1,1'-dichloroammonium and the carbon nanotubes to the organic solvent is (30-35):1 mg / mL.

[0012] The organic solvent comprises o-dichlorobenzene and n-butanol, and the volume ratio is (5-10):(2-5), preferably 7:3.

[0013] The reaction catalyst comprises acetic acid, and the concentration is 15-20 M.

[0014] The preparation of the flexible conductive carbon cloth coated with the viologen-based covalent organic framework material is that the viologen-based covalent organic framework material, a binder and a conductive agent are prepared into electrode slurry, and then the electrode slurry is dropped onto the carbon cloth.

[0015] The application further provides a preparation method of the wearable magnesium battery self-powered dressing for chronic wound healing.

[0016] 1) Preparation of a viologen-based covalent organic framework material

[0017] As described above;

[0018] 2) Preparation of an electrode

[0019] The purple base covalent organic framework material, the binder and the conductive agent are mixed and added into an organic solvent to obtain an electrode slurry, which is dropped onto a carbon cloth, and then dried to obtain an electrode material;

[0020] The mass ratio of the purple base covalent organic framework material, the binder and the conductive agent is (8-10):1:1;

[0021] The binder comprises polyvinylidene fluoride (PVDF);

[0022] The conductive agent comprises one or more of acetylene black, carbon nanotubes and graphene;

[0023] 3) Preparation of a solid-state electrolyte

[0024] Sodium alginate and acrylamide are dissolved and mixed uniformly, a crosslinking agent, a thermal initiator and a catalyst are added, and then poured into a polytetrafluoroethylene mold to react at room temperature to obtain a solid-state electrolyte;

[0025] The mass fraction of the dissolved sodium alginate solution is 1-2%;

[0026] The mass fraction of the dissolved acrylamide solution is 35-40%;

[0027] The crosslinking agent comprises N'-N-methylene bisacrylamide;

[0028] The thermal initiator comprises ammonium persulfate;

[0029] The catalyst comprises N,N,N,N-tetramethyl ethylenediamine;

[0030] 4) Preparation of a magnesium self-powered dressing

[0031] The prepared electrode, the solid-state electrolyte and the magnesium sheet are assembled to obtain a wearable magnesium self-powered dressing;

[0032] The specific operation of the assembly is as follows: the solid-state electrolyte is attached to the side with adhesion of a 3M dressing, the magnesium sheet and the electrode are overlaid on the electrolyte in parallel, the electrode serves as the positive electrode, the magnesium sheet serves as the negative electrode, the resistance is connected with the magnesium sheet and the electrode to form a closed loop, and thus a flexible wearable magnesium self-powered dressing is obtained.

[0033] The application also provides a use of the wearable magnesium battery self-powered dressing for chronic wound healing.

[0034] The application has the following beneficial effects:

[0035] The wearable magnesium battery self-powered dressing for chronic wound healing and the preparation method thereof provided by the application, which uses a flexible conductive carbon cloth coated with a viologen-based covalent organic framework material as a positive electrode of the battery, uses a magnesium sheet as a negative electrode, and uses a polyacrylamide hydrogel as a solid-state electrolyte, to assemble a flexible wearable self-powered dressing; wherein the TVCOF electrode obtained by coating a flexible carbon cloth with a viologen-based covalent organic framework material (TVCOF@CNT) as an antibacterial coating layer, improves the antibacterial performance of the carbon cloth, the positively charged TVCOF is conducive to bacterial adhesion, and viologen has strong redox properties; when the battery is discharged, the viologen V 2+ in the framework is reduced to V + , the generated V + is easily re-oxidized to V 2+ in an air atmosphere, accompanied by the generation of ROS, to promote the death of bacteria, and the battery can be quickly charged in air, and the battery reaction equation is Mg+1 / 2O2+H2O→Mg(OH)2. The TVCOF electrode can effectively input electrical stimulation to the wound surface, the dressing can simulate the endogenous electric field in the wound, induce the migration of fibroblasts, regulate the immune microenvironment of the wound, inhibit the inflammatory response, and the polyacrylamide gel electrolyte has good hygroscopicity, can absorb the exudate at the wound surface, maintain a moist healing environment, and effectively promote the healing of chronic wounds in rats. The self-powered dressing prepared by the application provides a reliable electrotherapy method for chronic wound healing. BRIEF DESCRIPTION OF DRAWINGS

[0036] Figure 1 The powder diffraction pattern of TVCOF and TVCOF@CNT;

[0037] Figure 2 The scanning electron microscope image of the TVCOF electrode;

[0038] Figure 3 The cyclic voltammogram of TVCOF and TVCOF@CNT;

[0039] Figure 4 The voltage change curve of the self-powered dressing in the electrochemical discharge-air self-charging process;

[0040] Figure 5 The discharge voltage curve of the self-powered dressing when different resistances are connected to the self-powered dressing;

[0041] Figure 6 The survival number of E. coli and S. aureus after different treatments;

[0042] Figure 7 The cell survival rate diagram of the TVCOF electrode, the magnesium sheet, the polyacrylamide hydrogel and the L929 fibroblasts after co-culture;

[0043] Figure 8 Fluorescence micrograph and proliferation histogram of L929 fibroblasts stimulated by the magnesium battery self-powered dressing prepared in the application;

[0044] Figure 9 Micrograph of L929 fibroblast migration stimulated by the magnesium battery self-powered dressing prepared in the application;

[0045] Figure 10 Expression level of CD86, a marker of Raw 264.7 macrophages, before and after applying electric stimulation to the magnesium battery self-powered dressing prepared in the application;

[0046] Figure 11 Actual photo and histogram of healing efficiency of the effect of the magnesium battery self-powered dressing prepared in the application on promoting chronic wound healing of rats;

[0047] Figure 12 Histological staining chart of the magnesium battery self-powered dressing prepared in the application for treatment of chronic wounds of rats;

[0048] Figure 13 Actual photo of the self-powered dressing. DETAILED DESCRIPTION

[0049] The application will be described in further detail below with specific implementation cases and accompanying drawings. It should be understood that these examples are only used to illustrate the application and are not used to limit the protection scope of the application. After reading the application, those skilled in the art can make various equivalent modifications of the application, which fall within the scope defined by the appended claims.

[0050] Unless otherwise specified, all raw materials and reagents of the application are conventional market raw materials and reagents.

[0051] Example 1

[0052] Preparation of wearable magnesium battery self-powered dressing for chronic wound healing

[0053] 1) Preparation of TVCOF@CNT viologen covalent organic framework material

[0054] 25.2 mg of triformylphloroglucinol (TP), 74.4 mg of 1,1'-bis(4-aminophenyl)-[4,4'-bipyridine]-1,1'-dichloroammonium (Vio-NH2) and 25 mg of carbon nanotubes were added to a Schlenk tube, respectively;

[0055] Then 2.8 mL of o-dichlorobenzene and 1.2 mL of n-butanol solution were added, and the mixture was ultrasonicated for 30 minutes;

[0056] Finally, 0.4 mL of acetic acid (17.5 M) was added, and the ultrasonic dispersion was continued for 10 minutes;

[0057] Three freeze-pumping-thaw cycles were performed under liquid nitrogen (77 K) and degassed;

[0058] After sealing the tube, the product TVCOF@CNT was obtained by placing it at room temperature for 24 hours. The product was washed with tetrahydrofuran and methanol multiple times, and the collected powder was dried in a vacuum drying box at 60°C for 12 hours, with a yield of about 50%.

[0059] TVCOF was prepared as above, except that no carbon nanotubes were added.

[0060] TVCOF@CNT and TVCOF were subjected to powder X-ray diffraction testing, and the results are shown in Figure 1 It can be seen that the characteristic peaks of TVCOF@CNT doped with carbon nanotubes are consistent with those of pure TVCOF, indicating that TVCOF@CNT was successfully synthesized.

[0061] 2) Preparation of TVCOF electrode

[0062] TVCOF@CNT, polyvinylidene fluoride, and acetylene black were mixed in a mass ratio of 8:1:1 in N-methylpyrrolidone to obtain a COF / PVDF / CNT mixed solution. The mixed solution was added dropwise to carbon cloth, and the mixture was loaded at a loading of about 500 μg / cm 2 to obtain a TVCOF electrode.

[0063] The resulting TCVOF electrode was subjected to scanning electron microscopy, and the results are shown in Figure 2 It can be observed that the viologen-based covalent organic framework TVCOF@CNT adheres to the flexible carbon cloth, and the purpose is to improve the antibacterial performance of the material through antibacterial coating modification.

[0064] 3) Preparation of solid-state electrolyte

[0065] Sodium alginate was dissolved in a 0.01M phosphate buffer solution to obtain a sodium alginate solution with a mass fraction of 1.4%. Acrylamide was dissolved in a 0.01M phosphate buffer solution to obtain an acrylamide solution with a mass fraction of 37%. The two solutions were mixed uniformly, and 3 mg of N’N-methylene bisacrylamide, 20 mg of ammonium persulfate, and 15 μL of N,N,N,N-tetramethyl ethylenediamine were added in sequence. The solution was poured into a polytetrafluoroethylene mold and reacted at room temperature for 3 hours to obtain a flexible polyacrylamide solid-state electrolyte.

[0066] 4) Preparation of magnesium self-powered dressing

[0067] The polyacrylamide solid electrolyte is pasted on the side with adhesion of the 3M patch, the magnesium sheet and the electrode are covered on the electrolyte in parallel, the electrode is used as the positive electrode and the magnesium sheet is used as the negative electrode, the resistance is connected with the magnesium sheet and the electrode to form a closed loop, and thus a flexible wearable magnesium self-powered dressing is obtained.

[0068] Example 2

[0069] Preparation of wearable magnesium battery self-powered dressing for chronic wound healing

[0070] 1) Preparation of viologen-based covalent organic framework material

[0071] 25.6 mg of tri-aldehyde-based phloroglucinol (TP), 74.4 mg of 1,1'-bis(4-aminophenyl)-[4,4'-bipyridine]-1,1'-dichloro ammonium (Vio-NH2) and 26 mg of carbon nanotubes are respectively added into a Schlenk tube;

[0072] Then 3.0 mL of o-dichlorobenzene and 1.5 mL of n-butanol solution are added, and the mixture is ultrasonically dispersed for 30 minutes;

[0073] Finally, 0.5 mL of acetic acid (17.5 M) is added, and the ultrasonic dispersion is continued for 10 minutes;

[0074] Under liquid nitrogen (77K), three cycles of freezing-pumping-thawing are carried out and degassing is performed;

[0075] After the tube is sealed, it is placed at room temperature for 24 hours to obtain the product TVCOF@CNT, and the product is washed with tetrahydrofuran and methanol for multiple times, and the collected powder is dried in a vacuum drying box at 60°C for 12 hours, and the yield is about 50%.

[0076] 2) Preparation of electrode

[0077] TVCOF@CNT, polyvinylidene fluoride and acetylene black are mixed in N-methyl pyrrolidone at a mass ratio of 10:1:1 to obtain a COF / PVDF / CNT mixed solution, the mixed solution is added dropwise to carbon cloth, and the loading amount of the mixture is about 500 μg / cm 2 , and thus a TVCOF electrode is obtained;

[0078] 3) Preparation of solid electrolyte

[0079] Sodium alginate was dissolved in 0.01M phosphate buffer solution to obtain a sodium alginate solution with a mass fraction of 1.4%, and acrylamide was dissolved in 0.01M phosphate buffer solution to obtain an acrylamide solution with a mass fraction of 37%. The two solutions were mixed uniformly, and 3 mg of N’N-methylene bisacrylamide, 20 mg of ammonium persulfate and 15 μL of N,N,N,N-tetramethyl ethylenediamine were added in turn. The solution was poured into a polytetrafluoroethylene mold, and the reaction was carried out at room temperature for 3 hours to obtain a flexible polyacrylamide solid-state electrolyte;

[0080] 4) Preparation of magnesium self-powered dressing

[0081] The polyacrylamide solid-state electrolyte was attached to the side with adhesion of the 3M dressing, and the magnesium sheet and the electrode were overlaid on the electrolyte in parallel, with the electrode as the positive electrode and the magnesium sheet as the negative electrode. The resistance was connected with the magnesium sheet and the electrode to form a closed loop, and a flexible wearable magnesium self-powered dressing was obtained.

[0082] Example 3

[0083] Preparation of wearable magnesium battery self-powered dressing for chronic wound healing

[0084] 1) Preparation of viologen-based covalent organic framework material

[0085] 23.2 mg of tri-aldehyde-based phloroglucinol (TP), 78.5 mg of 1,1'-bis(4-aminophenyl)-[4,4'-bipyridine]-1,1'-dichloro ammonium (Vio-NH2) and 26 mg of carbon nanotubes were added to a Schlenk tube, respectively;

[0086] Then 3.1 mL of o-dichlorobenzene and 1.5 mL of n-butanol solution were added, and the mixture was ultrasonicated for 30 minutes;

[0087] Finally, 0.5 mL of acetic acid (17.5 M) was added, and the ultrasonic dispersion was continued for 10 minutes;

[0088] Under liquid nitrogen (77K), three cycles of freezing-pumping-thawing were carried out and degassing was performed;

[0089] After the tube was sealed, it was placed at room temperature for 24 hours to obtain the product TVCOF@CNT. The product was washed with tetrahydrofuran and methanol for multiple times, and the collected powder was dried in a vacuum drying box at 60°C for 12 hours, with a yield of about 50%.

[0090] 2) Preparation of electrode

[0091] TVCOF@CNT, polyvinylidene fluoride and acetylene black were mixed in N-methyl pyrrolidone at a mass ratio of 9:1:1 to obtain a COF / PVDF / CNT mixed solution. The mixed solution was added dropwise to carbon cloth, and the loading amount of the mixture was about 500 μg / cm2 , to obtain a TVCOF electrode;

[0092] 3) Preparation of solid-state electrolyte

[0093] Sodium alginate was dissolved in 0.01M phosphate buffer solution to obtain a sodium alginate solution with a mass fraction of 1.4%, and acrylamide was dissolved in 0.01M phosphate buffer solution to obtain an acrylamide solution with a mass fraction of 37%. The two solutions were mixed uniformly, and 3 mg of N’N-methylene bisacrylamide, 20 mg of ammonium persulfate and 15 μL of N,N,N,N-tetramethyl ethylenediamine were added in turn. The solution was poured into a polytetrafluoroethylene mold and reacted at room temperature for 3 hours to obtain a flexible polyacrylamide solid-state electrolyte.

[0094] 4) Preparation of magnesium self-powered dressing

[0095] The polyacrylamide solid-state electrolyte was attached to the side with adhesion of the 3M dressing, and the magnesium sheet and the electrode were covered on the electrolyte in parallel, with the electrode as the positive electrode and the magnesium sheet as the negative electrode. The resistance was connected with the magnesium sheet and the electrode to form a closed loop, to obtain a flexible wearable magnesium self-powered dressing.

[0096] Test Example 1

[0097] The electrochemical performance of the TVCOF electrode prepared in Example 1 was evaluated by using an electrochemical workstation.

[0098] Cyclic voltammetry test was carried out in a three-electrode system with 0.01M phosphate buffer solution as electrolyte. The self-powered dressing assembled was evaluated for discharge capacity by a new battery test system.

[0099] The results are shown in Figure 3 Two pairs of obvious redox peaks were observed at -0.15 V / -0.44 V and -0.71 V / -0.95 V. After doping with carbon nanotubes, the peak current of TVCOF@CNT increased significantly, and the conductivity of the material was greatly improved, indicating that the electrochemical activity was enhanced. The two pairs of redox peaks are the two redox processes in the viologen segment of the material, i.e. the conversion between V 2+ , V + , and V 0 At different scanning rates (20 mV / S, 60 mV / S, 80 mV / S, 100 mV / S), it can be seen from the comparison of the cyclic voltammetry curves that the TVCOF electrode has strong charge storage capacity.

[0100] As shown in Figure 4 , the open-circuit voltage of the prepared magnesium battery self-powered dressing is about 1.6V, and the current density is 5-100 μA / cm 2The battery voltage can be restored to near the initial level within 12 hours, and the battery can autonomously restore the voltage in the presence of air without external devices for electrochemical charging.

[0101] As shown in Figure 5 , the discharge performance of the battery under different resistance loads was tested, and the output voltage of the battery was adjusted by different resistance loads. As the resistance value of the external resistance increased, the output voltage of the battery increased, and therefore the output voltage of the battery could be controlled by adjusting the resistance value.

[0102] Test Example 2

[0103] Evaluation of the antibacterial performance of the self-powered dressing by dilution plating method

[0104] Staphylococcus aureus and Escherichia coli (10 7 CFU / mL) were inoculated in physiological saline, and control group, Mg group, TVCOF electrode group and electric stimulation group were set up, and the bacterial solution was treated at 37℃ for 8 hours. 100 μL of gradient diluted bacterial solution was coated on LB agar plates and cultured for 24 hours. The growth of bacterial colonies was observed.

[0105] As shown in Figure 6 , through the graph of the number of surviving bacteria after different treatments of Staphylococcus aureus and Escherichia coli, compared with the other three groups, the self-powered co-culture group had almost no bacterial colony growth, indicating that the antibacterial ability of magnesium sheet and TVCOF electrode was limited and could not effectively eliminate all bacteria. The electric stimulation dressing assembled by magnesium negative electrode and TCOF / C positive electrode combined with electric field could effectively eliminate bacteria.

[0106] Test Example 3

[0107] Evaluation of the toxicity of the self-powered dressing and the ability of electric stimulation to promote cell proliferation and migration using fibroblast L929 cells

[0108] L929 fibroblast cells were selected to evaluate the cytotoxicity of the self-powered dressing. L929 cells were inoculated in 24-well plates at a density of 1×10 6 cells per well, and magnesium sheet, TVCOF electrode and polyacrylamide gel were co-cultured with the cells for 2 days, and the cell viability was detected by CCK8 reagent.

[0109] Two parallel T-shaped platinum wires were placed in each well of a 24-well plate, perpendicular to the bottom of the plate, and L929 cells were inoculated at a density of 1×10 4The density of 1 x 104cells per well was inoculated in 24-well plates, and after 12 hours of culture, platinum wire electrodes were linked to the electric stimulation dressing. The cells were subjected to electric stimulation for 0.5 hours every 12 hours, and the control group was not treated. After 48 hours of continuous culture, the cell viability was detected by CCK8, and the cells were dyed by Calcein-AM / PI, and observed under a microscope.

[0110] As shown in Figure 7 , the CCK8 test analysis showed that the cell viability remained basically unchanged within two days, and the proliferation of the cells was not inhibited, indicating that the self-powered dressing did not have adverse effects on the cell survival rate, and had good biocompatibility.

[0111] As shown in Figure 8 , the fluorescence staining results showed that the cell morphology after electric stimulation treatment had no obvious change, and the cell growth density of the electric stimulation group was larger. Compared with the control group, the electric field stimulation given under the induction of the self-powered dressing significantly promoted the proliferation of L929 cells, indicating that the electric stimulation output by the self-powered device was within the range that the cells could withstand, and had a positive effect on the cell proliferation.

[0112] As shown in Figure 9 , the exogenous electric field stimulation given under the induction of the self-powered dressing significantly promoted the migration of L929 cells to the center of the scratch area, which confirmed that the electric field generated by the self-powered device had a positive effect of guiding the migration of cells to the wound surface in the wound healing process, and further promoted the repair of the wound.

[0113] Test Example 4

[0114] Evaluation of the regulation ability of electric stimulation on inflammatory environment using Raw264.7 macrophages

[0115] Raw264.7 cells were cultured in complete medium for 12 hours, and then incubated with lipopolysaccharide (LPS) at a final concentration of 1 μg mL −1 for 24 hours. During the period, the self-powered dressing was connected for electric stimulation for 30 minutes every six hours. Finally, the macrophages in each group were collected, and the expression of CD86 antibody in the cell suspension was detected by flow cytometry.

[0116] As shown in Figure 10As shown, lipopolysaccharide was used as an inducer to stimulate M0 macrophages to polarize to M1 type inflammatory model, simulate the inflammatory process of wound environment, study the effect of self-powered dressing on the expression of inflammation under electric stimulation, and the flow cytometry results show that, compared with the blank control, after LPS stimulation, the expression of M1 type marker protein CD86 is significantly up-regulated, which further indicates that M1 polarization is successfully induced, and in the electric stimulation experiment group, the expression level of CD86 marker protein is significantly down-regulated, indicating that electric stimulation effectively inhibits the M1 polarization of macrophages. As a non-invasive treatment method, electric stimulation has potential application prospects in immune regulation of chronic wounds, and effectively inhibits excessive inflammation at the wound surface.

[0117] Test Example 5

[0118] Evaluation of the ability of self-powered dressing to promote wound repair

[0119] Select 200-250 g SD rats, after fasting for 12 hours, inject 1% STZ (60 mg / kg) solution (sodium citrate buffer, 0.1 mol / L, pH=4.5) into the abdominal cavity at one time, induce type I diabetes model, and 72 hours after injection, measure the blood glucose level of rats through tail vein blood sampling. Rats with blood glucose level ≥16.7 mmol / L are considered to be successful in modeling the diabetes model. Create a 10 mm full skin defect wound on the back of the rat, set up a control group, a non-electric stimulation group (i.e. TVCOF electrode and polyacrylamide gel dressing), and an electric stimulation group (self-powered dressing). On the 1st, 5th, 8th, and 14th day of treatment, take photos of the wound, calculate the wound area using ImageJ, and detect the wound pathological tissue using hematoxylin / eosin staining (HE) and Masson staining (MASSON).

[0120] As shown in Figure 11 , through the actual photo of the wound, it can be seen that the electric stimulation generated by the dressing can effectively promote wound repair. As can be seen from the wound simulation integral graph, on the 8th day, the wound of the electric stimulation group contracted to 15.4%, while the control group and the non-electric stimulation treatment group were 66.9% and 48.33% respectively. On the 14th day of treatment, the wound of the electric stimulation group closed more than 97%, and the epidermis grew basically intact at the wound site, indicating that the wound was successfully repaired, and the healing speed was significantly higher than that of the control group and the non-electric stimulation group. As shown in Figure 12 , in order to further evaluate the wound healing, the wound tissue was subjected to HE and MASSON staining. On the 14th day, the HE staining results showed that the epidermis in the control group and the non-electric stimulation treatment group was immature, and there were many tissue defects. The cross-section of the wound in the control group was still relatively large, while the formation of granulation tissue in the electric stimulation treatment group was more vigorous, and the epidermis regenerated well. Similarly, in the MASSON staining, the wound area of the electric stimulation group showed more ordered and dense blue collagen deposition fibers, and more skin organ appendages were generated.

[0121] As Figure 13 shown, it is a real picture of self-powered dressing. The polyacrylamide solid electrolyte is pasted on the side with adhesion of 3M dressing, the magnesium sheet and TVCOF electrode are covered on the electrolyte, and the resistance is linked with the magnesium sheet and TVCOF electrode to form a closed loop, and the wearable magnesium battery self-powered dressing is assembled.

[0122] The above proves that the magnesium battery dressing based on the positive electrode of viologen covalent organic framework material can effectively remove bacteria and promote the repair of chronic wounds.

Claims

1. A wearable magnesium battery self-powered dressing for chronic wound healing, characterized in that, It is a flexible wearable magnesium battery self-powered dressing prepared by using a flexible conductive carbon cloth coated with a viologen-based covalent organic framework material as a positive electrode, using a magnesium sheet as a negative electrode, and connecting the resistance and the carbon cloth and magnesium sheet through a solid-state electrolyte to form a closed loop. The viologen-based covalent organic framework material is prepared by adding a tri-aldehyde-based phloroglucinol, 1,1'-bis(4-aminophenyl)-[4,4'-bipyridine]-1,1'-dichloroammonium and carbon nanotubes into an organic solvent, ultrasonically mixing them uniformly, adding a reaction catalyst and continuing to ultrasonically mix them uniformly, and then allowing them to react at room temperature to obtain the viologen-based covalent organic framework material.

2. The wearable magnesium battery self-powered dressing for chronic wound healing according to claim 1, characterized in that, The mass ratio of the tri-aldehyde-based phloroglucinol to the 1,1'-bis(4-aminophenyl)-[4,4'-bipyridine]-1,1'-dichloroammonium is 1:(2-4).

3. The wearable magnesium battery self-powered dressing for chronic wound healing according to claim 1, characterized in that, The mass ratio of the mixture of the tri-aldehyde-based phloroglucinol and the 1,1'-bis(4-aminophenyl)-[4,4'-bipyridine]-1,1'-dichloroammonium to the carbon nanotubes is (3-5):

1.

4. The wearable magnesium battery self-powered dressing for chronic wound healing according to claim 1, characterized in that, The solid-liquid ratio of the tri-aldehyde-based phloroglucinol, the 1,1'-bis(4-aminophenyl)-[4,4'-bipyridine]-1,1'-dichloroammonium and the carbon nanotubes to the organic solvent is (30-35):1 mg / mL.

5. The wearable magnesium battery self-powered dressing for chronic wound healing according to claim 1, characterized in that, The organic solvent includes o-dichlorobenzene and n-butanol, and the volume ratio of the two is (5-10):(2-5).

6. The wearable magnesium battery self-powered dressing for chronic wound healing according to claim 1, characterized in that, The reaction catalyst includes acetic acid, and the concentration of the acetic acid is 15-20 M.

7. A method of manufacturing a wearable magnesium battery self-powered dressing for chronic wound healing according to any one of claims 1-6, characterized in that, The method comprises the following steps: 1) preparing a viologen-based covalent organic framework material The viologen-based covalent organic framework material is prepared as described in claim 1; 2) preparing an electrode The viologen-based covalent organic framework material, a binder and a conductive agent are mixed and added into an organic solvent to obtain an electrode slurry, which is then dropped onto a carbon cloth and dried to obtain an electrode material; 3) preparing a solid-state electrolyte Sodium alginate and acrylamide are separately dissolved and mixed uniformly, a crosslinking agent, a thermal initiator and a catalyst are added, and then poured into a polytetrafluoroethylene mold to react at room temperature to obtain a solid-state electrolyte; 4) preparing a magnesium self-powered dressing The solid-state electrolyte is attached to the side with adhesion of a 3M dressing, a magnesium sheet and an electrode are overlaid on the electrolyte in parallel, the electrode serves as a positive electrode and the magnesium sheet serves as a negative electrode, a resistance is connected with the magnesium sheet and the electrode to form a closed loop, and a flexible wearable magnesium battery self-powered dressing is obtained.

8. The process for the preparation of wearable magnesium battery self-powered dressing for chronic wound healing as claimed in claim 7 wherein, The mass ratio of the viologen-based covalent organic framework material, the binder and the conductive agent used in step 2) is (8-10):1:

1.

9. The process for the preparation of wearable magnesium battery self-powered dressing for chronic wound healing as claimed in claim 7 wherein, The binder used in step 2) includes polyvinylidene fluoride (PVDF). The conductive agent includes one or more of acetylene black, carbon nanotubes and graphene.

10. Use of the wearable magnesium battery self-powered dressing described in any one of claims 1-6 in the preparation of a wound healing material.

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