A hydrogen production anti-oxidation hydrogel microneedle patch with a primary cell effect and preparation and application thereof

Abstract

The application belongs to the technical field of medical materials, and specifically discloses a hydrogen production and oxidation resistance hydrogel microneedle patch based on a primary cell effect and a preparation method and application thereof, which comprises the following steps: preparing a polyvinyl alcohol solution, an aldehyde bacterial cellulose solution, a quaternary ammonium chitosan solution and a silver nanowire dispersion; preparing a needle tip solution; preparing a lower substrate solution; preparing an upper substrate solution; preparing a microneedle patch preliminary product; and performing salting-out treatment on the microneedle patch preliminary product with a sulfate solution, so as to obtain the hydrogen production and oxidation resistance hydrogel microneedle patch based on the primary cell effect. The hydrogen production and oxidation resistance hydrogel microneedle patch based on the primary cell effect is prepared by using the above method, the patch can spontaneously generate therapeutic microcurrent and hydrogen in a wound microenvironment, and can realize multi-mechanism synergistic treatment of chronic and difficult-to-heal wounds such as diabetes by synergizing photothermal antibacterial and drug activity.

Description

Technical Field

[0001] This invention belongs to the field of medical materials technology, specifically relating to a galvanic cell effect hydrogen-generating antioxidant hydrogel microneedle patch and its preparation and application. Background Technology

[0002] Chronic, refractory wounds, such as diabetic foot ulcers, pose a significant challenge to global healthcare due to their complex pathological microenvironment, including persistent high oxidative stress, susceptibility to secondary infection, local hypoxia, and inflammatory dysregulation. Traditional dressings and treatments often have limited effectiveness. Microneedling technology, capable of minimally invasively penetrating the stratum corneum to establish drug delivery channels and improve drug penetration efficiency, has been widely applied in wound healing. However, most existing drug-loaded microneedles only achieve passive drug release, resulting in a single treatment mechanism that struggles to synergistically address the multiple pathological factors of diabetic wounds and lacks the ability to actively respond to the dynamic wound microenvironment. Furthermore, therapies relying on external oxygen may exacerbate wound hypoxia, while long-term use of antibiotics can easily lead to drug resistance.

[0003] Electrical stimulation, as an effective physical intervention, has been proven to promote fibroblast migration, accelerate angiogenesis, and modulate inflammatory responses, thereby improving the healing process. However, most current electrical stimulation treatments rely on external power sources or complex devices, which have significant limitations in terms of portability, continuity, intelligence, and patient self-management. Therefore, developing a dressing that can utilize the endogenous wound environment to achieve self-powered, continuous therapeutic electrical stimulation has important clinical significance and application prospects.

[0004] Therefore, there is an urgent need in this field to develop a novel intelligent wound dressing that can accurately respond to the wound microenvironment, has self-powered properties, and integrates multi-dimensional treatment mechanisms, so as to achieve efficient regulation and comprehensive management of chronic and difficult-to-heal wounds such as diabetic wounds, and solve key problems in current treatments such as strong external dependence, single mechanism of action, and contradiction between antibacterial and tissue repair needs. Summary of the Invention

[0005] The purpose of this invention is to provide a galvanic cell effect hydrogen-generating antioxidant hydrogel microneedle patch, its preparation and application. This patch can spontaneously generate therapeutic microcurrents and hydrogen in the wound microenvironment, synergistically combining photothermal antibacterial and drug activity, thereby achieving multi-mechanism synergistic treatment of chronic and difficult-to-heal wounds such as diabetes.

[0006] To achieve the above objectives, the present invention provides a method for preparing a galvanic cell effect hydrogen-generating antioxidant hydrogel microneedle patch, comprising the following steps:

[0007] Step S1: Weigh a certain amount of polyvinyl alcohol (PVA), aldehyde-modified bacterial cellulose (OBC), quaternized chitosan (QCS), and silver nanowires (AgNWs), and dissolve them in deionized water respectively to obtain polyvinyl alcohol (PVA) solution, aldehyde-modified bacterial cellulose (OBC) solution, quaternized chitosan (QCS) solution, and silver nanowire (AgNWs) dispersions with a certain mass percentage concentration.

[0008] Step S2: Weigh the polyvinyl alcohol solution and silver nanowire dispersion, stir and mix them evenly at a stirring temperature of 85~95℃ and a stirring speed of 400~800r / min, cool to 50~60℃ and then add conductive photothermal material, hypoglycemic and anti-inflammatory drugs to obtain needle tip solution.

[0009] Step S3: Take polyvinyl alcohol solution, aldehyde bacterial cellulose solution, quaternized chitosan solution and silver nanowire dispersion, stir and mix them evenly at a temperature of 85~95℃ and a speed of 400~800r / min, cool to 50~60℃ and then add conductive photothermal material, hypoglycemic and anti-inflammatory drugs to obtain the lower substrate solution.

[0010] Step S4: Take polyvinyl alcohol solution, aldehyde bacterial cellulose solution and quaternized chitosan solution, stir and mix them evenly at a temperature of 85~95℃ and a speed of 400~800r / min, cool to 50~60℃ and then add conductive photothermal material, zinc particles and their compounds, hypoglycemic and anti-inflammatory drugs to obtain the upper substrate solution.

[0011] Step S5: Inject the needle tip solution into the microneedle mold, centrifuge to fill the needle tip cavity with the needle tip solution, remove excess solution, and place it in a freezer at a certain temperature for freezing and shaping; after taking it out, thaw it at room temperature, add the lower substrate solution, and place it in a freezer at a certain temperature for freezing and shaping again; after taking it out, thaw it at room temperature, and finally add the upper substrate solution. After multiple freeze-thaw cycles, the initial microneedle patch is obtained.

[0012] Step S6: Salt out the microneedle patch sample with sulfate solution to improve the mechanical properties of the hydrogel, thus obtaining a hydrogen-generating antioxidant hydrogel microneedle patch based on the galvanic cell effect.

[0013] Preferably, in step S1, the mass percentage concentration of the polyvinyl alcohol solution is 12.5-40%, the mass percentage concentration of the aldehyde-modified bacterial cellulose solution is 0.05-0.5%, and the mass percentage concentration of the quaternized chitosan solution is 0.05-0.3%.

[0014] Preferably, in step S2, the volume ratio of polyvinyl alcohol solution to silver nanowire dispersion is 8~10:1;

[0015] In step S3, the volume ratio of polyvinyl alcohol solution, aldehyde-modified bacterial cellulose solution, quaternized chitosan solution, and silver nanowire dispersion is 6~9:0.5~1:0.5~1:1.

[0016] In step S4, the volume ratio of polyvinyl alcohol solution, aldehyde-modified bacterial cellulose solution, and quaternized chitosan solution is 6~9:0.5~3:2~4.

[0017] Preferably, in steps S2, S3, and S4, the amount of conductive photothermal material added is 0.1-0.5% based on its mass in the corresponding total solution; the conductive photothermal material includes one or more of MXene, polypyrrole, polyaniline, and carbon nanotubes; the amount of hypoglycemic and anti-inflammatory drugs added is 0.1-1% based on its mass in the corresponding total solution; the hypoglycemic and anti-inflammatory drugs include one or more of metformin hydrochloride and insulin and its analogues, amoxicillin, alpha-lipoic acid, quercetin, curcumin, and growth factors.

[0018] Preferably, in step S5, the tip length of the microneedle mold is 400~800μm, and the tip shape of the microneedle mold is a cone, a triangular pyramid, or a regular square pyramid; the centrifugation speed is 3000~8000r / min, and the centrifugation time is 3~6min.

[0019] Preferably, in step S5, the freeze-thaw cycle specifically involves performing at least three freeze-thaw cycles, with the freezing temperature being -15 to -40°C, the freezing time being 8 to 14 hours, and the thawing time being 2 to 4 hours.

[0020] Preferably, in step S6, the anode material of the hydrogen-generating antioxidant hydrogel microneedle patch based on the galvanic cell effect includes zinc and its compounds, and the concentration of the anode material is 0.5~4%; the cathode material of the hydrogen-generating antioxidant hydrogel microneedle patch based on the galvanic cell effect includes silver and its compounds, and the concentration of the cathode material is 0.05~0.2%.

[0021] Preferably, in step S6, the concentration of the sulfate solution is 1~10M; the sulfate is one or more of sodium sulfate, ammonium sulfate, magnesium sulfate, and calcium sulfate.

[0022] The present invention also provides a method for preparing a galvanic cell effect hydrogen-generating antioxidant hydrogel microneedle patch.

[0023] This invention also provides an application of a galvanic cell effect hydrogen-generating antioxidant hydrogel microneedle patch in the treatment of chronic, refractory wounds.

[0024] This invention utilizes the above-mentioned galvanic cell effect hydrogen-generating antioxidant hydrogel microneedle patch, its preparation, and its application, with the following beneficial effects:

[0025] (1) Self-powered and hydrogen production: The patch in this invention forms a “zinc-silver” galvanic cell system through zinc particles on the upper layer of the substrate and silver nanowires on the lower layer and microneedle layer. This system can generate microcurrents in the electrolyte environment of wound tissue fluid, stimulate tissue regeneration, accelerate tissue repair, and continuously generate hydrogen gas with selective antioxidant effect in situ at the cathode under hypoxic conditions, effectively alleviating oxidative stress.

[0026] (2) Multiple antibacterial effects: This invention integrates the chemical antibacterial effects of silver nanowires, quaternized chitosan and drugs, the photothermal antibacterial effects of conductive photothermal materials and the physical antibacterial effects of microcurrents, which work synergistically, have a broad antibacterial spectrum and are not easy to induce drug resistance.

[0027] (3) Synergistic treatment: The microcurrent of the patch in this invention can stimulate cell proliferation and migration and may improve the transdermal efficiency of drugs; the loaded therapeutic drugs further provide anti-inflammatory and antioxidant effects, which are synergistic with the physical therapy mechanism.

[0028] (4) Good mechanical and biological properties: The PVA-based hydrogel microneedles reinforced by salting out have sufficient hardness (single needle strength 0.07~0.5N) to pierce the skin. At the same time, each component has good biocompatibility, high cell survival rate, and can regulate macrophage polarization.

[0029] (5) The zinc particles on the upper layer of the substrate and the silver nanowires in the lower layer and microneedle layer of the present invention can achieve multi-mechanism synergistic treatment by MXene photothermal antibacterial effect and anti-inflammatory and antioxidant activity of loaded drugs; it has excellent biocompatibility (NIH 3T3 fibroblast survival rate >95%). In the skin defect model of diabetic mice, it can promote collagen deposition and angiogenesis, reduce the level of reactive oxygen species in the wound by about 60%, and inhibit bacterial infection and local inflammation. Therefore, it is suitable for treating chronic and difficult-to-heal wounds such as difficult-to-heal diabetic wounds. On the 10th day, the wound healing rate exceeded 98%.

[0030] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0031] Figure 1 This is a microscope image of a galvanic cell effect hydrogen-generating antioxidant hydrogel microneedle patch of the present invention and the self-powered microneedles prepared in Example 1 of its preparation and application.

[0032] Figure 2 This is a microscopic image of hydrogen production by the self-powered microneedles prepared in Example 2 of the present invention, which is a hydrogen-generating and antioxidant hydrogel microneedle patch with galvanic cell effect and its preparation and application. Detailed Implementation

[0033] The technical solution of the present invention will be further described below with reference to the accompanying drawings and embodiments.

[0034] Unless otherwise defined, the technical or scientific terms used in this invention shall have the ordinary meaning as understood by one of ordinary skill in the art to which this invention pertains.

[0035] Example 1

[0036] A method for preparing a galvanic cell effect hydrogen-generating antioxidant hydrogel microneedle patch specifically includes the following steps:

[0037] Weigh 1.75 g of PVA and dissolve it in 10 mL of deionized water to form a PVA solution. Weigh 0.015 g of MXene and 0.005 g of AgNWs and dissolve them in 10 mL of PVA solution to form a needle tip solution. Weigh 0.01 g of OBC and disperse it in 10 mL of deionized water, then heat at 80 °C for 4 h to form an OBC dispersion. Weigh 1.75 g of PVA and dissolve it in 10 mL of the OBC dispersion to form a PVA / OBC solution. Weigh 0.05 g of QCS and dissolve it in the PVA / OBC solution to form a PVA / OBC / QCS solution. Weigh 0.015 g of MXene and 0.005 g of AgNWs and dissolve them in 10 mL of the PVA / OBC / QCS solution to form the lower substrate solution. Weigh 0.015 g of MXene and 0.1 g of Zn and dissolve them in 10 mL of PVA / OBC / QCS solution to form the upper substrate solution. First, add the needle tip solution to the microneedle mold, centrifuge to ensure complete filling of the mold needle tip, then remove excess solution and freeze at -30°C for 1 hour for setting. After removal, thaw at room temperature, add the lower substrate solution, and freeze again at -30°C for 1 hour for setting. After removal, thaw at room temperature, add the upper substrate solution, and finally place the microneedles in a freezer for three freeze-thaw cycles: freezing at -30°C for 11 hours and thawing at room temperature for 3 hours. This yields the initial microneedle patch. Then, salt out the initial microneedle patch using sodium sulfate solution to improve the mechanical properties of the microneedles, thus obtaining a hydrogen-generating antioxidant hydrogel microneedle patch based on the galvanic cell effect.

[0038] The mechanical properties of the hydrogel microneedle patch prepared in this embodiment were verified using a universal mechanical testing machine; the puncture performance of the hydrogel microneedle patch was verified using 3% agar to simulate skin strength. The results showed that... Figure 1As shown, the hydrogel microneedle patch prepared in this embodiment has a uniform distribution and size of needle tips, and the average needle tip strength of the self-powered microneedles is approximately 0.17 N, which is greater than the skin penetration strength of 0.07 N, indicating that the prepared hydrogel microneedle patch can penetrate the skin. Using a 3% agarose solution to simulate skin puncture, it can be seen that the needle tips of the hydrogel microneedle patch can completely puncture the skin and maintain their integrity after detachment. This indicates that the hydrogel microneedle patch has good mechanical properties, allowing it to puncture the skin and be completely removed, suggesting that the hydrogel microneedle patch can be applied to wound sites.

[0039] Example 2

[0040] A method for preparing a galvanic cell effect hydrogen-generating antioxidant hydrogel microneedle patch specifically includes the following steps:

[0041] Weigh 1.75 g of PVA and dissolve it in 10 mL of deionized water to form a PVA solution. Weigh 0.015 g of MXene and 0.005 g of AgNWs and dissolve them in 10 mL of the PVA solution to form a needle tip solution. Weigh 0.01 g of OBC and disperse it in 10 mL of deionized water, then heat at 80 °C for 4 h to form an OBC dispersion. Weigh 1.75 g of PVA and dissolve it in 10 mL of the OBC dispersion to form a PVA / OBC solution. Weigh 0.05 g of QCS and dissolve it in the PVA / OBC solution to form a PVA / OBC / QCS solution. Weigh 0.015 g of MXene and 0.005 g of AgNWs and dissolve them in 10 mL of the PVA / OBC / QCS solution to form the lower substrate solution. Weigh 0.015g of MXene and 0.1g of Zn and dissolve them in 10mL of PVA / OBC / QCS solution to form the upper substrate solution. First, add the tip solution to the microneedle mold, centrifuge to ensure complete filling of the mold tip, then remove excess solution and freeze at -30℃ for 1 hour for setting. After removal, thaw at room temperature, add the lower substrate solution, and freeze again at -30℃ for 1 hour for setting. After removal, thaw at room temperature, add the upper substrate solution, and finally place the microneedles in a freezer for three freeze-thaw cycles: freezing at -30℃ for 11 hours and thawing for 3 hours. This yields the initial microneedle patch. Then, salt out the initial microneedle patch using sodium sulfate solution to improve the mechanical properties of the microneedles, thus obtaining a hydrogen-generating antioxidant hydrogel microneedle patch based on the galvanic cell effect.

[0042] The open-circuit current and open-circuit voltage of the hydrogel microneedle patch prepared in this example were measured using an electrochemical workstation. The hydrogel microneedle patch was immersed in PBS to simulate an anaerobic environment in vivo, and the generation of hydrogen bubbles was observed under a microscope. The results showed that the hydrogel microneedle patch could continuously generate microcurrent and open-circuit voltage for 24 hours. This indicates that the hydrogel microneedle patch can continuously generate microcurrent at the wound site. Figure 2 As shown in the image, a microscope reveals that the hydrogel microneedle patch can continuously generate bubbles for 6 hours using PBS to simulate a body fluid environment, indicating that the hydrogel microneedle patch can continuously generate bubbles at the wound site for antioxidant purposes.

[0043] Example 3

[0044] A method for preparing a galvanic cell effect hydrogen-generating antioxidant hydrogel microneedle patch specifically includes the following steps:

[0045] Weigh 1.75 g of PVA and dissolve it in 10 mL of deionized water to form a PVA solution. Weigh 0.015 g of MXene and 0.005 g of AgNWs and dissolve them in 10 mL of the PVA solution to form a needle tip solution. Weigh 0.01 g of OBC and disperse it in 10 mL of deionized water, then heat at 80 °C for 4 h to form an OBC dispersion. Weigh 1.75 g of PVA and dissolve it in 10 mL of the OBC dispersion to form a PVA / OBC solution. Weigh 0.05 g of QCS and dissolve it in the PVA / OBC solution to form a PVA / OBC / QCS solution. Weigh 0.015 g of MXene and dissolve it in 10 mL of the PVA / OBC / QCS solution to form a PVA / OBC / QCS / MXene solution (PQOM).

[0046] Weigh 0.015 g of MXene and 0.005 g of AgNWs and dissolve them in 10 mL of PVA / OBC / QCS solution (PQO) to form the lower substrate solution. Weigh 0.015 g of MXene and 0.1 g of Zn and dissolve them in 10 mL of PVA / OBC / QCS solution to form the upper substrate solution. First, add the tip solution to the microneedle mold, centrifuge to ensure complete filling of the mold tip, then remove excess solution and freeze at -30°C for 1 hour for setting. After removal, thaw at room temperature, add the lower substrate solution, and freeze again at -30°C for 1 hour for setting. After removal, thaw at room temperature, add the upper substrate solution, and finally place the microneedles in the freezer for three freeze-thaw cycles: freezing at -30°C for 11 hours, and thawing at room temperature for 3 hours. The initial microneedle patch was obtained, and then salted out using sodium sulfate solution to improve the mechanical properties of the microneedles, thus obtaining a hydrogen-generating antioxidant hydrogel microneedle patch based on the galvanic cell effect. Magnesium chloride was then used to remove the salting-out state from the hydrogel microneedle patch. Simultaneously, hydrogels were prepared from the upper substrate solution, lower substrate solution, and PQOM solution, respectively, and named the drug-free hydrogel microneedle patch MIN. The photothermal properties of different samples were tested using a thermal imager.

[0047] The results showed that under ten minutes of illumination, PQO, PQOM, and PQOM... AgNWs (Hydrogel prepared by adding silver nanowires to PQOM (equivalent to the lower substrate solution)), PQOM Zn The ΔT values ​​for the hydrogel (equivalent to the upper substrate solution) prepared by adding zinc to PQOM and MIN were 5.7, 32.6, 27.4, 34.5 and 35.6 °C, respectively. It can be seen that adding MXene material can significantly improve the photothermal performance of the hydrogel. Among them, the hydrogel material with added AgNWs appears gray and may affect the photothermal performance of some hydrogels. However, overall, adding MXene endows the self-powered microneedles with good photothermal performance.

[0048] Example 4

[0049] A method for preparing a galvanic cell effect hydrogen-generating antioxidant hydrogel microneedle patch specifically includes the following steps:

[0050] Weigh 0.01 g of OBC and disperse it in 10 mL of deionized water, then heat at 80 °C for 4 h to form an OBC dispersion. Weigh 1.75 g of PVA and dissolve it in 10 mL of the OBC dispersion to form a PVA / OBC solution. Weigh 0.05 g of QCS and dissolve it in the PVA / OBC solution to form a PVA / OBC / QCS solution (PQO). Weigh 0.015 g of MXene and dissolve it in 10 mL of the PVA / OBC / QCS solution to form a PVA / OBC / QCS / MXene solution (PQOM). Weigh 1.75 g of PVA and dissolve it in 10 mL of deionized water to form a PVA solution. Weigh 0.015 g of MXene, 0.005 g of AgNWs, and 0.005 g of metformin hydrochloride and dissolve them in 10 mL of the PVA solution to form a needle tip solution. Weigh 0.01 g of OBC and disperse it in 10 mL of deionized water, then heat at 80 °C for 4 h to form an OBC dispersion. Weigh 1.75 g of PVA and dissolve it in 10 mL of the OBC dispersion to form a PVA / OBC solution. Weigh 0.05 g of QCS and dissolve it in the PVA / OBC solution to form a PVA / OBC / QCS solution. Weigh 0.015 g of MXene, 0.005 g of AgNWs, and 0.05 g of metformin hydrochloride and dissolve them in 10 mL of the PVA / OBC / QCS solution to form the lower substrate solution. Weigh 0.015 g of MXene, 0.1 g of Zn, and 0.05 g of metformin hydrochloride and dissolve them in 10 mL of the PVA / OBC / QCS solution to form the upper substrate solution. First, the needle tip solution was added to the microneedle mold, centrifuged to ensure complete filling of the needle tip area, and then excess solution was removed. The mold was then frozen at -30°C for 1 hour for setting. After removal, it was thawed at room temperature, a lower substrate solution was added, and it was frozen again at -30°C for 1 hour for setting. After removal, it was thawed at room temperature, and an upper substrate solution was added. Finally, the microneedles were subjected to three freeze-thaw cycles: freezing at -30°C for 11 hours and thawing at room temperature for 3 hours. This yielded the initial microneedle patch. Sodium sulfate solution was then used to salt out the initial microneedle patch, improving its mechanical properties, resulting in a hydrogen-generating antioxidant hydrogel microneedle patch based on the galvanic cell effect. Magnesium chloride was then used to remove the salt-out condition from the hydrogel microneedle patch. The drug-free hydrogel microneedle patch was named MIN; the drug-added hydrogel microneedle patch was named MINA. The antibacterial properties of different samples were tested.

[0051] The results showed that the antibacterial rates of PQO and PQOM blends were 76% and 98%, respectively. After forming a galvanic cell and adding drugs, the bactericidal rate could reach 99.9%. The antibacterial performance under near-infrared light (NIR) conditions could reach 100%, indicating that the hydrogel microneedle patch has multifunctional synergistic antibacterial effects such as photothermal, microcurrent, and chemical stimulation.

[0052] Example 5

[0053] A method for preparing a galvanic cell effect hydrogen-generating antioxidant hydrogel microneedle patch specifically includes the following steps:

[0054] Weigh 1.75 g of PVA and dissolve it in 10 mL of deionized water to form a PVA solution. Weigh 0.015 g of MXene, 0.005 g of AgNWs, and 0.005 g of metformin hydrochloride and dissolve them in 10 mL of the PVA solution to form a needle tip solution. Weigh 0.01 g of OBC and disperse it in 10 mL of deionized water, then heat at 80 °C for 4 h to form an OBC dispersion. Weigh 1.75 g of PVA and dissolve it in 10 mL of the OBC dispersion to form a PVA / OBC solution. Weigh 0.05 g of QCS and dissolve it in the PVA / OBC solution to form a PVA / OBC / QCS solution. Weigh 0.015 g of MXene, 0.005 g of AgNWs, and 0.05 g of metformin hydrochloride and dissolve them in 10 mL of the PVA / OBC / QCS solution to form the lower substrate solution. Weigh 0.015g of MXene, 0.1g of Zn, and 0.05g of metformin hydrochloride and dissolve them in 10mL of PVA / OBC / QCS solution to form the upper substrate solution. First, add the needle tip solution to the microneedle mold and centrifuge to ensure complete filling of the needle tip portion. Then, remove excess solution and freeze at -30℃ for 1 hour to set the shape. After removal, thaw at room temperature, add the lower substrate solution, and freeze again at -30℃ for 1 hour to set the shape. After removal, thaw at room temperature, add the upper substrate solution, and finally, perform three freeze-thaw cycles: freezing at -30℃ for 11 hours and thawing at room temperature for 3 hours. This yields the initial microneedle patch. Then, salt out the initial microneedle patch using sodium sulfate solution to improve the mechanical properties of the microneedles, resulting in a hydrogen-generating antioxidant hydrogel microneedle patch based on the galvanic cell effect. Finally, remove the salt-out state of the hydrogel microneedle patch using magnesium chloride.

[0055] The drug-free hydrogel microneedle patch was named MIN; the drug-added hydrogel microneedle patch was named MINA, and the cell group co-cultured with the hydrogel microneedle patches was named MINA+ES. The effects of different samples on cells were tested. The results showed that on the third day, the cell viability of the MIN and MINA groups were 91.8% and 98%, respectively, both greater than 90%, indicating that MIN has good biocompatibility; the cell viability of the MINA+ES group reached 110%, indicating that the microcurrent generated by the hydrogel microneedle patch had a significant effect on promoting cell proliferation; the cell migration rates of the control group, MIN, and MINA on the third day were 54.2%, 66.2%, and 70.85%, respectively, indicating that MIN and MINA have the effect of promoting cell migration. The cell migration rate of the MINA+ES group could be further improved to 73.1%, indicating that the microcurrent also has a certain influence on cell migration.

[0056] Example 6

[0057] A method for preparing a galvanic cell effect hydrogen-generating antioxidant hydrogel microneedle patch specifically includes the following steps:

[0058] Weigh 1.75 g of PVA and dissolve it in 10 mL of deionized water to form a PVA solution. Weigh 0.015 g of MXene, 0.005 g of AgNWs, and 0.005 g of metformin hydrochloride and dissolve them in 10 mL of the PVA solution to form a needle tip solution. Weigh 0.01 g of OBC and disperse it in 10 mL of deionized water, then heat at 80 °C for 4 h to form an OBC dispersion. Weigh 1.75 g of PVA and dissolve it in 10 mL of the OBC dispersion to form a PVA / OBC solution. Weigh 0.05 g of QCS and dissolve it in the PVA / OBC solution to form a PVA / OBC / QCS solution. Weigh 0.015 g of MXene, 0.005 g of AgNWs, and 0.05 g of metformin hydrochloride and dissolve them in 10 mL of the PVA / OBC / QCS solution to form the lower substrate solution. Weigh 0.015g of MXene, 0.1g of Zn, and 0.05g of metformin hydrochloride and dissolve them in 10mL of PVA / OBC / QCS solution to form the upper substrate solution. First, add the needle tip solution to the microneedle mold and centrifuge to ensure complete filling of the needle tip portion. Then, remove excess solution and freeze at -30℃ for 1 hour to set the shape. After removal, thaw at room temperature, add the lower substrate solution, and freeze again at -30℃ for 1 hour to set the shape. After removal, thaw at room temperature, add the upper substrate solution, and finally, perform three freeze-thaw cycles: freezing at -30℃ for 11 hours and thawing at room temperature for 3 hours. This yields the initial microneedle patch. Then, salt out the initial microneedle patch using sodium sulfate solution to improve the mechanical properties of the microneedles, resulting in a hydrogen-generating antioxidant hydrogel microneedle patch based on the galvanic cell effect. Finally, remove the salt-out state of the hydrogel microneedle patch using magnesium chloride.

[0059] Hydrogel microneedle patches that do not form a galvanic cell circuit were named MIN; those with added medication were named MINA; and those without added medication were named MINE. The effects of different samples were tested. Results showed that the wound healing rates for the control group, MIN, MINE, and MINA were 50%, 54%, 64%, and 80% at 7 days, respectively, and 81%, 82%, 85%, and 98% at 10 days. This indicates that compared to the control group, microneedle material alone has little effect on wound healing, but adding microcurrent stimulation can slightly improve the wound healing rate. Adding medication to the hydrogel microneedle patch can significantly improve the wound healing rate through the synergistic effect of microcurrent and medication.

[0060] Experimental Example 1

[0061] Weigh out 0.005 g, 0.01 g, 0.015 g, and 0.02 g of OBC respectively, disperse them in 10 mL of deionized water, and heat at 80 °C for 4 h to form an OBC dispersion. Weigh out 1.25 g, 1.5 g, 1.75 g, and 2 g of PVA respectively, and dissolve them in 10 mL of the OBC dispersion to form a PVA / OBC solution. Weigh out 0.05 g, 0.1 g, 0.15 g, and 0.2 g of QCS respectively, and dissolve them in the PVA / OBC solution to form a PVA / OBC / QCS solution. Weigh out 0.005 g, 0.01 g, 0.015 g, 0.02 g, and 0.025 g of MXene respectively, and disperse them in the PVA / OBC / QCS solution to form a PVA / OBC / QCS / MXene solution. Hydrogels with different raw material ratios were prepared using the cyclic freeze-thaw method according to the above proportions. The cyclic freeze-thaw method specifically involves subjecting the molded system to three freeze-thaw cycles. The freeze-thaw temperature is -15 to -40°C, the freezing time is 8 to 14 hours, and the thawing time is 2 to 4 hours.

[0062] The tensile properties of the prepared hydrogels were tested using a universal testing machine. The results showed that the elongation at break of 12.5% ​​(wt) PVA, 15% (wt) AM, 17.5% (wt) AM, and 20% (wt) AM were 228.2%, 459.6%, 493.8%, and 237.5%, respectively, and the tensile stresses were 104.4, 153.1, 270, and 236.1 kPa, respectively. The tensile stresses of 0.05% (wt) OBC, 0.1% (wt) OBC, 0.15% (wt) OBC, and 0.2% (wt) OBC were also tested. The elongation at break of (wt) OBC was 387.4, 493.8, 526.7 and 414.1%, respectively, and the tensile stress was 160.1, 270, 157.2 and 167.2 kPa, respectively. The elongation at break of 0.5% (wt) QCS, 1% (wt) QCS, 1.5% (wt) QCS and 2% (wt) QCS was 493.8, 308.4, 401.5 and 391.4%, respectively, and the tensile stress was 270, 208.4, 228.4 and 195.7 kPa, respectively.

[0063] Therefore, the optimal ratio for preparing microneedle patches is 17.5% PVA, 0.1% OBC, 0.5% QCS, and 0.15% MXene, with an elongation at break of 493.5% and a tensile stress of 270 kPa.

[0064] Experiment Example 2

[0065] Weigh 0.01 g of OBC and disperse it in 10 mL of deionized water, then heat at 80 °C for 4 h to form an OBC dispersion. Weigh 1.75 g of PVA and dissolve it in 10 mL of the OBC dispersion to form a PVA / OBC solution. Weigh 0.05 g of QCS and dissolve it in the PVA / OBC solution to form a PVA / OBC / QCS solution. Weigh 0.005 g, 0.01 g, 0.015 g, 0.02 g, and 0.025 g of MXene respectively, and disperse them in the PVA / OBC / QCS solution to form a PVA / OBC / QCS / MXene solution. Hydrogels with different MXene ratios were prepared using a cyclic freeze-thaw method according to the above proportions. The conductivity of the prepared hydrogels was tested using an electrochemical workstation.

[0066] The results showed that the electrical conductivities of 0.1%, 0.15%, 0.2%, and 0.25% (wt) MXene were 0.782, 0.813, 0.785, and 0.765 S / m, respectively, indicating that the 0.15% MXene content resulted in the highest conductivity. Therefore, the hydrogel with 0.15% MXene exhibits the best conductivity and can better form a galvanic cell circuit.

[0067] Therefore, the present invention employs the above-mentioned hydrogen-generating antioxidant hydrogel microneedle patch based on the galvanic cell effect, its preparation method and application. This patch can spontaneously generate therapeutic microcurrents and hydrogen in the wound microenvironment, synergistically combining photothermal antibacterial and drug activity, thereby achieving multi-mechanism synergistic treatment of chronic and difficult-to-heal wounds such as diabetes.

[0068] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the technical solutions of the present invention, and these modifications or equivalent substitutions cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A method for preparing a galvanic cell effect hydrogen-generating antioxidant hydrogel microneedle patch, characterized in that, Includes the following steps: Step S1: Weigh polyvinyl alcohol, aldehyde-modified bacterial cellulose, quaternized chitosan and silver nanowires, and dissolve them in deionized water to obtain polyvinyl alcohol solution, aldehyde-modified bacterial cellulose solution, quaternized chitosan solution and silver nanowire dispersion, respectively. Step S2: Take polyvinyl alcohol solution and silver nanowire dispersion, stir and mix them evenly at a stirring temperature of 85~95℃ and a stirring speed of 400~800r / min, cool to 50~60℃ and then add conductive photothermal material, hypoglycemic and anti-inflammatory drugs to obtain needle tip solution. Step S3: Take polyvinyl alcohol solution, aldehyde-modified bacterial cellulose solution, and quaternized chitosan solution, and stir and mix them evenly at a temperature of 85~95℃ and a speed of 400~800r / min. After cooling to 50~60℃, add cathode material silver nanowires, conductive photothermal material, hypoglycemic and anti-inflammatory drugs to obtain the lower substrate solution. Step S4: Take polyvinyl alcohol solution, aldehyde bacterial cellulose solution and quaternized chitosan solution, stir and mix them evenly at a temperature of 85~95℃ and a speed of 400~800r / min, cool to 50~60℃ and then add zinc particles of anode material, conductive photothermal material, hypoglycemic and anti-inflammatory drugs to obtain the upper substrate solution. Step S5: Inject the needle tip solution into the microneedle mold, centrifuge to fill the needle tip cavity with the needle tip solution, remove excess solution, and place it in a refrigerator for freezing and shaping; after taking it out, thaw it at room temperature, add the lower substrate solution, and place it in a refrigerator for freezing and shaping again; after taking it out, thaw it at room temperature, and finally add the upper substrate solution. After multiple freeze-thaw cycles, the initial microneedle patch is obtained. Step S6: Salt out the microneedle patch sample with sulfate solution to obtain a hydrogen-generating antioxidant hydrogel microneedle patch based on the galvanic cell effect.

2. The method for preparing a galvanic cell effect hydrogen-generating antioxidant hydrogel microneedle patch according to claim 1, characterized in that: In step S1, the mass percentage concentration of the polyvinyl alcohol solution is 12.5-40%, the mass percentage concentration of the aldehyde-modified bacterial cellulose solution is 0.05-0.5%, and the mass percentage concentration of the quaternized chitosan solution is 0.05-0.3%.

3. The method for preparing a galvanic cell effect hydrogen-generating antioxidant hydrogel microneedle patch according to claim 1, characterized in that: In step S2, the volume ratio of polyvinyl alcohol solution to silver nanowire dispersion is 8~10:1; In step S3, the volume ratio of polyvinyl alcohol solution, aldehyde-modified bacterial cellulose solution, quaternized chitosan solution, and silver nanowire dispersion is 6~9:0.5~1:0.5~1:

1. In step S4, the volume ratio of polyvinyl alcohol solution, aldehyde-modified bacterial cellulose solution, and quaternized chitosan solution is 6~9:0.5~3:2~4.

4. The method for preparing a galvanic cell effect hydrogen-generating antioxidant hydrogel microneedle patch according to claim 1, characterized in that: In steps S2, S3, and S4, the amount of conductive photothermal material added is 0.1-0.5% of its mass in the corresponding total solution; the conductive photothermal material includes one or more of MXene, polypyrrole, polyaniline, and carbon nanotubes; the amount of hypoglycemic and anti-inflammatory drugs added is 0.1-1% of its mass in the corresponding total solution; the hypoglycemic and anti-inflammatory drugs include one or more of metformin hydrochloride and insulin, amoxicillin, alpha-lipoic acid, quercetin, curcumin, and growth factors.

5. The method for preparing a galvanic cell effect hydrogen-generating antioxidant hydrogel microneedle patch according to claim 1, characterized in that: In step S5, the tip length of the microneedle mold is 400~800μm, and the tip shape of the microneedle mold is a cone, a triangular pyramid, or a regular square pyramid; the centrifugation speed is 3000~8000r / min, and the centrifugation time is 3~6min.

6. The method for preparing a galvanic cell effect hydrogen-producing antioxidant hydrogel microneedle patch according to claim 1, characterized in that, In step S5, the freeze-thaw cycle specifically involves performing at least three freeze-thaw cycles, with the freezing temperature ranging from -15 to -40°C, the freezing time from 8 to 14 hours, and the thawing time from 2 to 4 hours.

7. The method for preparing a galvanic cell effect hydrogen-generating antioxidant hydrogel microneedle patch according to claim 1, characterized in that: In step S4, the mass concentration of the anode material in the upper substrate solution is 0.5~4%; in step S3, the mass concentration of the cathode material in the lower substrate solution is 0.05~0.2%.

8. The method for preparing a galvanic cell effect hydrogen-generating antioxidant hydrogel microneedle patch according to claim 1, characterized in that: In step S6, the concentration of the sulfate solution is 1~10M; the sulfate is one or more of sodium sulfate, ammonium sulfate, magnesium sulfate, and calcium sulfate.

9. A method for preparing a galvanic cell effect hydrogen-generating antioxidant hydrogel microneedle patch according to any one of claims 1-8.

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