Self-cascade photo-thermal response core-shell microneedle patch as well as preparation method and application thereof

Abstract

The invention relates to a self-cascade photo-thermal response core-shell microneedle patch as well as a preparation method and application thereof, and belongs to the technical field of biological medicines. A self-cascade photo-thermal response core-shell microneedle patch comprises a backing layer and a microneedle array arranged on the backing layer, the microneedle array is composed of a plurality of microneedles with core-shell structures, each core-shell microneedle comprises a photo-thermal response phase change shell and a soluble inner core, and the shells are filled with the soluble inner cores. The invention also provides a core-shell microneedle-hydrogel patch group, which comprises the core-shell microneedle patch and the hydrogel patch. The core-shell microneedle patch provided by the invention can realize controllable release of drugs, and a combined treatment platform is formed through an anti-oxidation-oxygen production-anti-inflammatory multi-target collaborative strategy. The patch group provided by the invention has temperature responsiveness, reversible adhesion and skin moistening and moisturizing effects, and can realize rapid adhesion and painless stripping.

Description

Technical Field

[0001] The present invention relates to a self-cascading photothermal response core-shell microneedle patch and a preparation method and application thereof, belonging to the technical field of biomedicine. Background Art

[0002] Psoriasis is a chronic inflammatory skin disease whose primary clinical manifestations are epidermal thickening accompanied by erythema and scaling, severely impacting patients' physical and mental well-being. Studies have shown that oxidative stress, persistent inflammation, and localized tissue hypoxia caused by excessive production of reactive oxygen species (ROS) are key contributors to its pathogenesis. ROS not only promote excessive keratinocyte proliferation but also activate various signaling pathways to release inflammatory cytokines and mediators, exacerbating abnormal keratinocyte proliferation and amplifying the inflammatory response. The interaction between oxidative stress and psoriatic skin inflammation creates a vicious cycle. Furthermore, hypoxia can further exacerbate the condition. Abnormal keratinocyte proliferation leads to localized hypoxia. Under hypoxic conditions, these cells adapt by increasing the expression of hypoxia-inducible factors (HIFs), further promoting keratinocyte proliferation. Therefore, scavenging ROS, inhibiting inflammatory responses, and alleviating hypoxia are important approaches to slowing disease progression.

[0003] Transdermal drug delivery systems are drug delivery systems that absorb through the skin, achieving systemic or local therapeutic effects and achieving disease treatment. Compared with traditional drug delivery methods, transdermal drug delivery systems have advantages such as high patient compliance, avoidance of first-pass effects, and reduced side effects. Traditional dosage forms for transdermal drug delivery include creams, patches, gels, and sprays. Ointments are commonly used for the topical treatment of psoriasis, but their inability to effectively penetrate the skin's stratum corneum barrier reduces their therapeutic efficacy. Furthermore, ointments have disadvantages such as a greasy texture and high viscosity, which limit their application in topical treatments. Compared to traditional transdermal drug delivery systems, microneedles are a novel transdermal delivery system that combines the advantages of subcutaneous injection and transdermal delivery. They offer advantages such as minimal invasiveness, painlessness, and improved patient compliance. They can physically penetrate the skin's stratum corneum barrier to achieve effective drug delivery. However, most current microneedles have a simple structure, a relatively simple mode of action, uncontrollable drug release, and lack of firm anchoring in local skin tissue, making it difficult to achieve combined treatment of psoriasis through multiple mechanisms. Summary of the Invention

[0004] In view of the deficiencies of the prior art, the present invention provides a self-cascading photothermal responsive core-shell microneedle patch and a preparation method and application thereof.

[0005] In order to achieve the above purpose, the technical means adopted by the present invention are as follows:

[0006] The self-cascading photothermal response core-shell microneedle patch comprises a backing layer and a microneedle array arranged on the backing layer, the microneedle array is composed of a plurality of microneedles with a core-shell structure, and a single core-shell microneedle comprises a photothermal responsive phase change shell and a soluble inner core filled in the shell, wherein the backing layer comprises hyaluronic acid, the soluble inner core comprises microalgae and polyvinylpyrrolidone, and the phase change shell comprises quercetin-iron nanoscale enzyme, gelatin and carrageenan.

[0007] In the technical solution, the array number of the core-shell microneedle patch is greater than 5*5.

[0008] In the technical solution, the core-shell microneedle is in the shape of a quadrangular pyramid, the needle tip height is 600-1200 μm, the needle tip diameter is not greater than 20 μm, the needle body diameter is 300-500 μm, and the microneedle base diameter is 5-20 mm.

[0009] Preferably, the microalgae are one or more of cyanophyta, chlorophyta, rhodophyta, phaeophyta or chrysophyta.

[0010] Preferably, the quercetin-iron nanoscale enzyme is prepared by the following method: mixing a methanol solution of iron chloride hexahydrate and a methanol solution of polyvinylpyrrolidone, then adding a methanol solution of quercetin under stirring, stirring for 3 h, transferring to a dialysis bag, dialyzing in water overnight, and obtaining the quercetin-iron nanoscale enzyme, wherein the concentration of the iron chloride hexahydrate is 10-30 mg / mL, the concentration of the polyvinylpyrrolidone is 10-20 mg / mL, and the concentration of the quercetin is 5-15 mg / mL; and the volume ratio of the methanol solution of iron chloride hexahydrate, the methanol solution of polyvinylpyrrolidone and the methanol solution of quercetin is 1:5:1.

[0011] Another object of the present application is to provide a preparation method of the core-shell microneedle patch.

[0012] (1) preparing a backing layer and a microneedle inner core: adding a mixed aqueous solution of microalgae and polyvinylpyrrolidone into a microneedle mold, centrifuging at 2000-4000 rpm for 4-6 min to remove bubbles and fill the microneedles, removing the excess solution, then adding a hyaluronic acid solution into the mold, centrifuging, drying at room temperature, and demolding to obtain the backing layer and the microneedle inner core;

[0013] (2) preparing a microneedle shell: filling a mixed aqueous solution of quercetin-iron nanoscale enzyme, gelatin and carrageenan into another microneedle mold with the same specifications as in step (1), centrifuging at 2000-4000 rpm for 10-30 min, and cooling and solidifying to obtain the microneedle shell;

[0014] (3) preparing a core-shell microneedle patch: gently pressing the backing layer and the microneedle inner core obtained in step (1) into the microneedle shell obtained in step (2), drying, and demolding to obtain the core-shell microneedle patch.

[0015] In the technical scheme, in the step (1), the concentration of the microalgae in the mixed aqueous solution is 4-8 mg / mL, and the mass percentage of the polyvinylpyrrolidone is 10%.

[0016] In the technical scheme, in the step (1), the mass percentage of the hyaluronic acid is 5%.

[0017] In the technical scheme, in the step (1), the time of the room temperature drying is greater than or equal to 1 h.

[0018] In the technical scheme, in the step (2), the concentration of the quercetin-iron nanoscale enzyme in the mixed aqueous solution is 400-1200 μg / mL, the mass percentage of the gelatin is 30%, and the mass percentage of the carrageenan is 0.5%.

[0019] A further object of the present application is to provide a core-shell microneedle-hydrogel patch set with reversible adhesion, which comprises a core-shell microneedle patch and a hydrogel patch, wherein,

[0020] The core-shell microneedle patch is the core-shell microneedle patch described above or prepared by the preparation method described above; and the hydrogel patch is prepared from a temperature-sensitive polymer material and a natural moisturizing factor.

[0021] Preferably, the temperature-sensitive polymer material is gelatin, and the natural moisturizing factor is sodium lactate.

[0022] The patch set described in the present application adopts a design of independent packaging of the core-shell microneedle patch and the hydrogel patch, which can effectively avoid the penetration of water in the hydrogel into the microneedle in long-term contact, thereby ensuring that the microneedle can effectively pierce the stratum corneum.

[0023] Further, the use method of the core-shell microneedle-hydrogel patch set is as follows: first, the core-shell microneedle patch with self-cascading photothermal response is pierced into the skin, and then the hydrogel patch is covered on the backing layer of the core-shell microneedle patch, and pressed for 3 min to make the two closely adhere to each other; after near-infrared light and white light irradiation treatment, the patch set is iced for 30 s to reduce the interfacial adhesion by using the low-temperature shrinkage effect, and the microneedle patch is peeled off painlessly.

[0024] Further, the patch set described in the present application can effectively exert the photothermal response of the quercetin-iron nanoscale enzyme after near-infrared light irradiation, promote the dissolution of the microneedle, and realize the controlled release of the drug; and after white light irradiation, the oxygen production capacity of the microalgae can be effectively increased, and the hypoxic microenvironment of the local tissue can be significantly improved.

[0025] In the technical scheme, the preparation method of the hydrogel patch in the core-shell microneedle-hydrogel patch set comprises the following steps: stirring a warm polymer material aqueous solution and a natural moisturizing factor aqueous solution at 50 DEG C in a water bath to obtain a uniform solution, pouring the solution into a culture dish, and obtaining the hydrogel patch after the solution is cooled and solidified.

[0026] Further, the mass percentage of gelatin is 16.7%, and the mass percentage of sodium lactate is 40%.

[0027] Another object of the present application is to provide the use of the self-cascading photothermal response core-shell microneedle patch or the reversibly adhered core-shell microneedle-hydrogel patch set in the preparation of a medicament for treating an inflammatory skin disease.

[0028] Further, the inflammatory skin disease is psoriasis.

[0029] The present application has the following advantages:

[0030] (1) The microneedle provided by the present application has a core-shell structure and temperature responsiveness, the microneedle shell comprises quercetin-iron nanoszyme, gelatin and carrageenan, and the microneedle soluble core comprises microalgae and a soluble polymer polyvinylpyrrolidone. The gelatin and the carrageenan have photothermal sensitivity, and the quercetin-iron nanoszyme has good near-infrared absorption performance. Therefore, the microneedle shell prepared based on this can be driven to dissolve by near-infrared light, realizing controllable release of the drug and ensuring high efficiency of the drug delivery mode.

[0031] (2) The quercetin-iron nanoszyme loaded in the microneedle shell also has superoxide dismutase activity, which can catalyze the conversion of superoxide anion to hydrogen peroxide; the microalgae loaded in the microneedle core have catalase activity, which can further catalyze the conversion of hydrogen peroxide to oxygen and water, thereby constructing a complete active oxygen cascade removal pathway and effectively exerting an anti-inflammatory effect. At the same time, the microalgae have photosynthetic oxygen production capacity and can continuously generate oxygen under light conditions, significantly improving the hypoxic microenvironment of the local tissue. The present application adopts a multi-target synergistic strategy of "antioxidation-oxygen production-anti-inflammation", forming a combined treatment platform integrating multiple mechanisms.

[0032] (3) The hydrogel patch in the core-shell microneedle-hydrogel patch set provided by the present application is prepared from gelatin and sodium lactate, which have temperature responsiveness, reversible adhesion and moisturizing effects, and can realize rapid adhesion and painless peeling. BRIEF DESCRIPTION OF DRAWINGS

[0033] Figure 1 (A) is a transmission electron microscope image of the quercetin-iron nanoszyme prepared in the examples; Figure 1 (B) is an X-ray powder diffraction pattern of the quercetin-iron nanoszyme prepared in the examples; Figure 1 (C) is the UV-visible absorption spectrum of the quercetin-iron nanozyme prepared in the example; Figure 1 (D) is a graph showing the superoxide dismutase activity of the quercetin-iron nanozyme prepared in the example.

[0034] Figure 2 (A) is an image showing the growth of Chlorella cultured in the example over a week; Figure 2 (B) is a graph showing the photosynthetic oxygen production capacity of Chlorella at different concentrations; Figure 2 (C) shows the oxygen production capacity of Chlorella vulgaris when incubated with hydrogen peroxide at different concentrations; Figure 2 (D) is a graph showing the activity of catalase at different concentrations of Chlorella.

[0035] Figure 3 Schematic diagram of the core-shell microneedle preparation process of the present invention.

[0036] Figure 4 (A) is a microscopic image of the core of the core-shell microneedle prepared in the present invention; Figure 4 (B) is a microscopic image of the shell of the core-shell microneedle prepared in the present invention; Figure 4 (C) is a microscope image of the core-shell microneedle prepared in the present invention; Figure 4 (DF) are scanning electron micrographs of the core-shell microneedles prepared in the present invention.

[0037] Figure 5 (A) Photothermal curves of core-shell microneedles containing different concentrations of quercetin-iron nanozymes prepared in the present invention; Figure 5 (B) is a photothermal curve of blank microneedles, microneedles containing Chlorella, and microneedles containing quercetin-iron nanozyme / Chlorella prepared in the present invention; Figure 5 (C) is a photothermal stability diagram of the core-shell microneedles prepared in the present invention; Figure 5 (D) is a photothermal image of different microneedles prepared in the present invention.

[0038] Figure 6 This is a picture of the photothermal responsive dissolution of the core-shell microneedles prepared in the present invention.

[0039] Figure 7 (A) is a schematic diagram of the reversibly adhesive hydrogel patch prepared in the present invention; Figure 7 (B) is a picture of the temperature-responsive adhesion and peeling of the reversibly adhesive hydrogel patch prepared by the present invention at the finger joint; Figure 7 (C) is a picture of the temperature-responsive adhesion and peeling of the reversibly adhesive hydrogel patch prepared by the present invention at the wrist joint; Figure 7 (D) is a picture of the temperature-responsive adhesion and peeling of the reversibly adhesive hydrogel patch prepared in the present invention on the back skin of mice.

[0040] Figure 8 (A) Photos of the back skin of mice in different drug-dosing groups at the end of treatment; Figure 8 (B) Squamous scale scores of mice in different drug groups at the end of treatment; Figure 8 (C) Erythema scores of mice in different drug-dosing groups at the end of treatment; Figure 8 (D) Epidermal thickening scores of mice in different drug groups at the end of treatment; Figure 8 (E) Psoriasis area and total severity index scores of mice in different drug groups at the end of treatment.

[0041] Figure 9 (A) H&E staining of skin tissues of mice in different drug-dosing groups at the end of treatment; Figure 9 (B) Images of epidermal thickness measurements of mice in different drug groups at the end of treatment.

[0042] Figure 10 Figures show the results of (A) Ki67, (B) TNF-α and (C) HIF-α determination in skin tissues of mice in different drug groups at the end of treatment.

[0043] Figure 11 (A) H&E staining results of tissues and organs of mice in different drug-treated groups; Figure 11 (B) is an image showing the irritation evaluation of the core-shell microneedles penetrating the skin. DETAILED DESCRIPTION

[0044] The following non-limiting examples may enable those skilled in the art to more fully understand the present invention, but are not intended to limit the present invention in any way.

[0045] Unless otherwise specified, the experimental methods described in the following examples are conventional methods; the reagents and materials described are all commercially available unless otherwise specified.

[0046] The preparation method of quercetin-iron nanozyme used in the following examples is as follows: a methanol solution of ferric chloride hexahydrate (20 mg mL -1 , 1 mL) was added dropwise to a methanol solution of polyvinyl pyrrolidone (13.2 mg mL -1 , 5mL) and stirred for 5min. Then, a methanol solution of quercetin (10mg·mL -1 , 1 mL) was added to the above mixture and stirred for 3 h. After the reaction was completed, the mixture was transferred to a dialysis bag and dialyzed in water overnight to obtain quercetin-iron nanozyme. Figure 1 (A) is a transmission electron microscopy image of the prepared quercetin-iron nanozyme, which shows that its shape is irregular and roughly uniformly distributed ultra-small particles. Figure 1(B) is the X-ray powder diffraction pattern of the prepared quercetin-iron nanozyme. It can be seen that the quercetin molecule shows a crystalline diffraction peak, while the diffraction peak of the quercetin-iron nanozyme disappears, indicating that after the formation of the nanostructure, the quercetin-iron nanozyme exhibits an amorphous structural feature. Figure 1 (C) is the UV-visible absorption spectrum of the prepared quercetin-iron nanozyme. It can be seen that the quercetin molecule exhibits two different absorption peaks at 256nm and 374nm, while the quercetin-iron nanozyme shows an absorption peak at 296nm. The change in the absorption peak indicates the existence of charge transfer interaction between quercetin and metal. Figure 1 (D) is the superoxide dismutase activity assay of the prepared quercetin-iron nanozyme. It can be seen that the scavenging ability of quercetin-iron nanozyme on ·O2ˉ is concentration-dependent. When the concentration is 400 μg·mL -1 When , the clearance rate of ·O2ˉ reached 77.76%, indicating that it has good superoxide dismutase activity.

[0047] The Chlorella cultivation method used in the following examples is as follows: First, BG-11 culture medium containing various components in various proportions is placed in a culture bottle. The Chlorella solution is then added to the bottle. The bottle mouth is covered with a breathable membrane to prevent contamination by external bacteria and to maintain internal ventilation. The bottle is then incubated at room temperature for a period of time. The Chlorella is cultured by shaking the bottle at different time intervals and using an incandescent lamp for cyclic illumination. A daily cycle of 12 hours of light and 12 hours of darkness is selected to provide a suitable growth environment for the Chlorella. Figure 2 (A) shows the growth of cultured Chlorella over a week. The image shows that the absorbance at 680 nm gradually increases over time, indicating growth. The solution color remains emerald green throughout the week, gradually deepening, indicating healthy growth. Figure 2 (B) is a graph showing the photosynthetic oxygen production capacity of Chlorella at different concentrations. It can be seen that Chlorella has the ability to continuously produce O2 within 12 hours of continuous illumination, and the oxygen production capacity of Chlorella is concentration-dependent. When the concentration of Chlorella is 600 μg·mL -1 The cumulative oxygen production within 12 h was the highest, reaching 16.7 mg·L -1 . Figure 2 (C) is the oxygen production capacity diagram when different concentrations of Chlorella are co-incubated with hydrogen peroxide. It can be seen from the figure that as the concentration of Chlorella increases, the amount of dissolved oxygen produced gradually increases. When the final concentration of Chlorella is 600 μg·mL -1 The cumulative oxygen production reached 17.3 mg·L within 10 min. -1 , indicating its good catalase activity. Figure 2(D) is the determination of catalase activity of Chlorella vulgaris at different concentrations. It can be seen that the removal of H2O2 is concentration-dependent. When the concentration of Chlorella vulgaris is 600 μg·mL -1 When the H2O2 removal rate was 2.5%, the H2O2 removal rate could reach about 60%. These results indicate that Chlorella vulgaris has good catalase-like activity.

[0048] Example 1

[0049] A method for preparing a self-cascading photothermal responsive core-shell microneedle loaded with quercetin-iron nanozyme and Chlorella vulgaris comprises the following steps:

[0050] Preparation of microneedle core: First, a solution of Chlorella vulgaris (8.5 mg mL -1 ) was mixed with a polyvinyl pyrrolidone aqueous solution (30%, w / v) in a mass ratio of 2:1 to prepare a Chlorella solution containing 10% polyvinyl pyrrolidone; then, 100 μL of the above solution was carefully added to a microneedle mold with a needle length of 1000 μm and an array number of 10×10, and the mold was transferred to a centrifuge tube equipped with a support base and centrifuged at 3000 rpm for 5 minutes to allow the solution to fully fill the microneedles. After drying at room temperature for 1 hour, the above steps were repeated; then, excess liquid in the mold was removed; then, 5% hyaluronic acid solution was added to the above microneedle mold, centrifuged at 3000 rpm for 5 minutes to remove bubbles, and used as a backing material; finally, the mold was dried at room temperature and demolded to obtain a microneedle core.

[0051] Preparation of core-shell microneedles: First, prepare a mixed aqueous solution of gelatin and carrageenan containing quercetin-iron nanozyme, wherein the concentration of quercetin-iron nanozyme is 400 μg / mL, the mass percentage of gelatin is 30%, and the mass percentage of carrageenan is 0.5%; melt the above mixed solution at 40°C, and then add it to a microneedle mold with the same specifications as the above-prepared core. Place the mold in a centrifuge tube and centrifuge at 3950 rpm for 20 minutes to fill the microneedles, remove the residual solution, cool and solidify, and finally gently insert the above-mentioned dried microneedle core into this microneedle mold, dry it at room temperature, and carefully demold it.

[0052] The preparation process of core-shell microneedles is as follows Figure 3 shown.

[0053] Example 2

[0054] Morphological observation and evaluation of the self-cascade photothermal responsive core-shell microneedles loaded with quercetin-iron nanozyme and Chlorella obtained in Example 1:

[0055] The microneedle shell, microneedle core and core-shell microneedle were observed using an optical microscope. The appearance of the core-shell microneedle was observed using a scanning electron microscope. Figure 4 As shown. Microscopic results show that in the microneedle core structure, Chlorella is enriched in the needle tip ( Figure 4 A); after drying, the microneedle shell forms a clear cavity structure ( Figure 4 B); The core-shell microneedles showed clear inner and outer layer distribution characteristics, with Chlorella evenly distributed in the inner layer and nanozymes in the outer layer, and the microneedles were intact ( Figure 4 C). Scanning electron microscopy results showed that the core-shell microneedles were in a well-shaped quadrangular pyramid with a complete morphology ( Figure 4 DF).

[0056] Example 3

[0057] Evaluation of the photothermal effect and photothermal responsiveness of the self-cascade photothermal responsive core-shell microneedles loaded with quercetin-iron nanozyme and Chlorella obtained in Example 1:

[0058] First, the photothermal conversion performance of the core-shell microneedles was evaluated. Considering that the loading amount of quercetin-iron nanozyme will affect the photothermal performance of the microneedles, too low a concentration may not provide enough heat to trigger the dissolution of the microneedles, and too high a concentration may cause skin damage due to excessive temperature. In order to determine the concentration of quercetin-iron nanozyme in the microneedles, microneedle matrix solutions containing different initial concentrations of quercetin-iron nanozyme were prepared to prepare core-shell microneedles, and the amount of Chlorella was kept the same during the process. The core-shell microneedles containing different concentrations of quercetin-iron nanozyme were irradiated with 808nm near-infrared light at an irradiation power of 0.5W / cm 2 At the same time, a near-infrared thermal imager was used to monitor and record the changes in solution temperature in real time, and a temperature-time curve was drawn to determine the optimal quercetin-iron nanozyme concentration. The results are shown in Figure 2. Figure 5 As shown in (A) and (D), it can be seen that compared with water, the temperature of the core-shell microneedles rises faster and reaches a higher temperature; with the increase of nanozyme concentration, the maximum temperature reached also gradually increases. When the concentration of quercetin-iron nanozyme is 1600 μg·mL -1 When the temperature of the core-shell microneedle reaches 49.2℃, the shell material can dissolve at a temperature of 40℃. Figure 5 As shown in (B), the microneedles containing only Chlorella also exhibited certain photothermal properties, which may be due to the enrichment of Chlorella at the needle tip giving the microneedles photothermal properties. Due to the photothermal properties of the nanozymes, the core-shell microneedles showed a higher temperature increase. In order to test the photothermal stability of the core-shell microneedles, the core-shell microneedles were placed under 808nm near-infrared laser with 0.5W / cm 2 The power density of the microneedle was irradiated for 5 minutes and then cooled for 5 minutes. Five cycles were tested to observe the stability of the microneedle after multiple irradiations. The photothermal cycle curve was drawn. The results are shown in the figure. Figure 5 As shown in (C), it can be seen that after 5 cycles of on / off of the near-infrared light, the highest temperature at the first irradiation can still be reached, indicating its good photothermal stability.

[0059] The photothermal responsiveness of core-shell microneedles was studied in agarose gel, which simulates the interstitial fluid of human skin. A 1.4% agarose gel was prepared and poured into a glass dish. After cooling and solidification, the core-shell microneedles were pressed into the agarose gel. Then, the gel was exposed to 808nm near-infrared laser irradiation (1.0W / cm 2 , 5min), and the dissolution of the needle tip was observed and recorded using an optical microscope at different time points. At the same time, the microneedles without near-infrared light irradiation were used as controls. The results are shown in Figure 6 As shown in the figure, after being inserted into the agarose gel, the core-shell microneedle tip swelled rapidly without being irradiated with near-infrared light, but did not dissolve. However, after being irradiated with near-infrared light, the shell of the core-shell microneedle dissolved, and this dissolution of the shell caused the core to come into contact with water, causing it to dissolve as well. This result demonstrates that the shell of the core-shell microneedle is temperature-sensitive, and that near-infrared light can be used to control the release of the microneedle shell and core.

[0060] Example 4

[0061] Preparation method of a reversibly adhesive hydrogel patch bonded to the core-shell microneedles obtained in Example 1 and evaluation of its temperature-responsive adhesion performance:

[0062] Gelatin (0.4 g) was added to deionized water (1.04 g) and fully swelled for 1 hour; then, sodium lactate (0.96 g) was added to the above solution and stirred in a 50°C water bath for 1 hour to obtain a uniform solution. The solution was poured into a culture dish and cut into 2.5 cm × 2.5 cm shapes after cooling and solidification. The on-demand adhesion and separation properties of the hydrogel were evaluated. In order to investigate the body temperature-triggered adhesion properties of the hydrogel, the prepared hydrogel was cut into a certain shape and applied to the wrist joint and index finger joint. When the hydrogel temperature rose to near body temperature, the joint was moved to observe its adhesion properties. Subsequently, the hydrogel was iced with an ice pack for 30 seconds to evaluate the peeling performance after ice application.

[0063] To evaluate the adhesion of the hydrogel in practical applications, the microneedle patch was inserted into the shaved area on the back of the mouse, and then the hydrogel was placed on the backing layer of the microneedle patch and pressed for 3 minutes to increase the temperature of the hydrogel to achieve sufficient adhesion. Then, the gel was peeled off with tweezers to observe its adhesion. To examine its temperature responsiveness, it was iced with an ice pack for 30 seconds and then peeled off again to evaluate its peeling performance after ice compress.

[0064] Schematic diagram of temperature-responsive adhesion Figure 7(A) shows the temperature-responsive adhesion performance results. Figure 7 As shown in (BD), it can be seen that: due to the high skin temperature, it can adhere firmly to the joints, and after ice compress, it immediately turns milky white and loses its stickiness, and can be easily peeled off; in actual application, the same phenomenon can be observed. The hydrogel patch can firmly fix the microneedle patch on the back skin of the mouse. After ice compress, both can be easily and painlessly peeled off.

[0065] Example 5

[0066] Application of the core-shell microneedle-hydrogel patch combination in the treatment of psoriasis mouse models:

[0067] To establish a psoriasis mouse model, BALB / c mice were first shaved of their back hair. Subsequently, 62.5 mg of 5% imiquimod cream was applied to the shaved skin of the mice daily for 6 days. Simultaneously, the mice were randomly divided into 6 groups of 3 mice each and received different treatments. Imiquimod cream was administered daily, 6 hours after application, starting on the first day of model establishment and continuing for 6 days. The experimental groups and administration methods are as follows: Group G1: no treatment; Group G2: 5% IMQ cream (62.5 mg) was applied until absorption; Group G3: 5% imiquimod cream (62.5 mg) was applied until absorption, and 6 hours later, the microneedle-hydrogel patch group loaded only with Chlorella was applied, and then the back skin was irradiated with white light; Group G4: 5% imiquimod cream (62.5 mg) was applied until absorption, and 6 hours later, the microneedle-hydrogel patch group loaded only with nanozymes was applied; Group G5: 5% imiquimod cream (62.5 mg) was applied until absorption, and 6 hours later, the core-shell microneedle-hydrogel patch group was applied, and then the back skin was irradiated with white light; Group G6: 5% imiquimod cream (62.5 mg) was applied until absorption, and 6 hours later, the core-shell microneedle-hydrogel composite patch was applied, and then the 808 nm near-infrared laser was irradiated for 5 minutes. After the irradiation, white light was then used to irradiate the skin on the back.

[0068] During the modeling period, the severity of erythema, scaling, and skin thickening on the back skin of the mice was scored daily using the Psoriasis Area and Severity Index (PASI), and the three scoring items were summed to obtain a total score. On the 7th day, the back skin of mice in each group was photographed. Figure 8(A) shows representative images of the back skin of mice in each group at the end of treatment. It can be seen that compared with the control group, the model group mice (G2 group) showed skin thickening, erythema and scaling, indicating that the psoriasis mouse model was successfully established. On the 7th day, compared with the G2 group, the different microneedle treatment groups showed different degrees of improvement in the symptoms of imiquimod-induced psoriasis, especially in the relief of scaling. This is because the hydrogel patch played a moisturizing and hydrating role, which helped to alleviate the symptoms of the disease. The PASI scores of mice in each group for 7 consecutive days are shown in Figure 2. Figure 8 Individual scores for scaling, erythema, and skin thickening (BE) showed that mice in the G2 group had the highest scores for each category. These scores decreased after different microneedle treatments, with the lowest scores observed in the core-shell microneedle group (G6) irradiated with near-infrared and white light. Overall, the PASI score was highest in the G2 model group, reaching a peak on day 6. Similar trends were observed in the other groups, but overall PASI scores were lower than those in the G2 group. The core-shell microneedle group (G6) irradiated with near-infrared and white light had the lowest score, indicating a favorable therapeutic effect.

[0069] H&E staining of skin tissue was used to observe epidermal thickening. The back skin of mice in different treatment groups was fixed with 4% paraformaldehyde, embedded in paraffin, sliced, and stained with H&E. The epidermal thickening of the skin tissue was observed under a microscope. The histological analysis results of H&E staining of the lesion area are shown in Figure 2. Figure 9 As shown in (A) and (B), it can be seen that the epidermal thickness of the normal group mice was thinner, while the mice in the imiquimod-induced model group (G2 group) showed obvious epidermal thickening and showed symptoms of acanthosis. The epidermal thickening of the mice in each microneedle treatment group was alleviated to varying degrees. The core-shell microneedle group irradiated with near-infrared light and white light had a better inhibition on epidermal thickness than the other groups, and the epidermal thickness was the lowest (G6 group).

[0070] Immunohistochemistry was used to measure the expression of several psoriasis-related proteins to investigate the pathological changes in psoriasis mice after different treatments. Ki67 is a marker of cell proliferation, and its expression in the epidermis reflects keratinocyte proliferation. Therefore, immunohistochemistry was used to detect Ki67 expression. The results showed that compared with the control group, Ki67 expression was dramatically upregulated in IMQ-treated skin tissue, and each treatment group exhibited varying degrees of inhibitory effects on Ki67 ( Figure 10 A). Among them, the inhibitory effect of the core-shell microneedle group irradiated with near-infrared and white light was the most significant. These findings are consistent with the results of histopathological observations. This indicates that the core-shell microneedle effectively inhibits keratinocyte proliferation by simulating antioxidant enzyme activity. The inflammatory environment of psoriatic lesions is characterized by the secretion of various inflammatory cytokines. The expression of TNF-α in skin tissue is shown in Figure 2. Figure 10As shown in (B), it can be seen that TNF-α was significantly increased in the imiquimod-induced psoriasis mouse model group and significantly decreased after core-shell microneedle treatment with near-infrared light and white light irradiation. This is mainly because the core-shell microneedle intervened in the process by simulating the activity of antioxidant enzymes, effectively reducing the expression level of inflammatory factors. Hypoxia-inducible factor-1α (HIF-1α) is often used as a biomarker of hypoxia, so the expression level of HIF-1α in the skin tissue of each group was also evaluated, and the results are shown in Figure 2. Figure 10 As shown in (C), it can be seen that: compared with the control group, the expression level of HIF-1α in imiquimod-induced psoriasis mice was significantly increased; in contrast, the expression of HIF-1α in the mice treated with Chlorella was reduced, and the core-shell microneedle groups treated with near-infrared light and white light were superior to the other groups in terms of HIF-1α clearance, which was mainly due to the oxygen-replenishing ability of photosynthetic oxygen production and catalase-like activity of Chlorella.

[0071] Example 6

[0072] In vivo safety evaluation of core-shell microneedle patches:

[0073] After the experiment in Example 5, the tissues and organs of mice in groups G1, G2, and G6 were collected and fixed in 4% paraformaldehyde. H&E staining was performed to investigate their in vivo safety. In addition, the skin irritation of the core-shell microneedle patch was investigated. The core-shell microneedle patch was applied to the back skin of depilated mice, and the recovery of the back skin holes was observed at different times. H&E staining of tissue and organ sections collected from different groups is shown in Figure 5. Figure 11 As shown in (A), it can be seen that no obvious necrosis and damage were found in the tissues and organs, and no obvious histological lesions were found, indicating that the preparation has good biocompatibility and biosafety. Figure 11 As shown in (B), after microneedle removal, a distinct microporous structure was observed on the skin surface. After 20 minutes, the micropores on the skin surface had essentially recovered, and no erythema had occurred. These results indicate that the core-shell microneedle patch is less irritating to the skin.

Claims

1. A self-cascading photothermal responsive core-shell microneedle patch, characterized by: The core-shell microneedle patch includes a backing layer and a microneedle array arranged on the backing layer. The microneedle array is composed of several microneedles with a core-shell structure. A single core-shell microneedle includes a photothermal responsive phase change shell and a soluble core. The soluble core is filled in the shell. The backing layer contains hyaluronic acid, the soluble core contains microalgae and polyvinylpyrrolidone, and the phase change shell contains quercetin-iron nanozyme, gelatin and carrageenan.

2. The core-shell microneedle patch according to claim 1, characterized in that: The array number of the core-shell microneedle patch is greater than 5×5; the core-shell microneedles are in the shape of a quadrangular pyramid, with a height of 600-1200 μm, a needle tip diameter of no more than 20 μm, a needle body diameter of 300-500 μm, and a microneedle base diameter of 5-20 mm.

3. The core-shell microneedle patch according to claim 1, characterized in that: The microalgae are one or more of Cyanobacteria, Chlorophyta, Rhodophyta, Phaeophyta or Chrysophyta.

4. The core-shell microneedle patch according to claim 1, wherein: The quercetin-iron nanozyme is prepared by the following method: mixing a hexahydrate ferric chloride methanol solution and a polyvinyl pyrrolidone methanol solution, then adding the quercetin methanol solution under stirring conditions, stirring for 3 hours, transferring the mixture to a dialysis bag, and dialyzing in water overnight to obtain the quercetin-iron nanozyme, wherein the concentration of the hexahydrate ferric chloride is 10-30 mg / mL, the concentration of the polyvinyl pyrrolidone is 10-20 mg / mL, and the concentration of the quercetin is 5-15 mg / mL; the volume ratio of the hexahydrate ferric chloride methanol solution, the polyvinyl pyrrolidone methanol solution and the quercetin methanol solution is 1:5:

1.

5. The method for preparing the core-shell microneedle patch according to any one of claims 1 to 4, characterized in that: The steps include: (1) Preparation of backing layer and microneedle core: Add a mixed aqueous solution of microalgae and polyvinyl pyrrolidone into a microneedle mold, centrifuge at 2000-4000 rpm for 4-6 minutes to remove bubbles and fill the microneedles, remove excess solution, then add hyaluronic acid solution into the above mold, centrifuge, dry at room temperature, and demold. (2) Preparation of microneedle shell: filling a mixed aqueous solution of quercetin-ferro nanozyme, gelatin and carrageenan into another microneedle mold with the same specifications as in step (1), centrifuging at 2000-4000 rpm for 10-30 min, and cooling and solidifying; (3) Preparation of core-shell microneedle patch: Gently press the backing layer and microneedle core obtained in step (1) into the microneedle shell obtained in step (2), and demould after drying.

6. The preparation method according to claim 5, characterized in that: In step (1), the concentration of microalgae in the mixed aqueous solution is 4-8 mg / mL, the mass percentage of polyvinyl pyrrolidone is 10%; the mass percentage of hyaluronic acid is 5%; and the drying time at room temperature is ≥1h; In the step (2), in the mixed aqueous solution, the concentration of quercetin-iron nanozyme is 400-1200 μg / mL, the mass percentage of gelatin is 30%, and the mass percentage of carrageenan is 0.5%.

7. A reversibly adherent core-shell microneedle-hydrogel patch assembly, characterized in that: The patch set includes a core-shell microneedle patch and a hydrogel patch, wherein: The core-shell microneedle patch is the core-shell microneedle patch according to any one of claims 1 to 4 or the core-shell microneedle patch prepared by the preparation method according to claim 5 or 6; The hydrogel patch is made of temperature-sensitive polymer material and natural moisturizing factor.

8. The core-shell microneedle-hydrogel patch assembly according to claim 7, characterized in that: The temperature-sensitive polymer material is gelatin, and the natural moisturizing factor is sodium lactate.

9. The core-shell microneedle-hydrogel patch assembly according to claim 7, characterized in that: The preparation method of the hydrogel patch includes the following steps: stirring an aqueous solution of a thermosensitive polymer material and an aqueous solution of a natural moisturizing factor in a 50°C water bath to obtain a uniform solution, pouring the solution into a culture dish, and waiting for the solution to cool and solidify to obtain a hydrogel patch, wherein the mass percentage of gelatin is 16.7% and the mass percentage of sodium lactate is 40%.

10. Use of the self-cascading photothermal responsive core-shell microneedle patch according to claim 1 or the core-shell microneedle-hydrogel patch assembly according to claim 7 in the preparation of a drug for treating inflammatory skin diseases.

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