Near-infrared triggered drug-loaded calcium-based pneumatic microneedle patch, preparation method and application thereof

Abstract

The application discloses a near-infrared triggered drug-loaded calcium-based pneumatic microneedle patch as well as a preparation method and application thereof. The microneedle patch comprises a backing layer and microneedle bodies on the backing layer. The microneedle bodies comprise microneedle cores and microneedle shells covering the microneedle cores. The microneedle shells comprise a microneedle framework material, tartaric acid and a photoinitiator. The microneedle cores comprise calcium carbonate and near-infrared photothermal nano drugs. The near-infrared photothermal nano drugs are composed of photothermal nano materials and drugs. The application adopts a near-infrared controllable triggered core pneumatic reaction, and relies on a shell-core structure calcium acid to construct an internal controllable pneumatic driving force through in-situ directional gas production. The gas production process synchronously releases functional calcium ions and therapeutic drugs in-situ, realizes efficient and controllable pneumatic deep-layer drug delivery, and simultaneously plays a synergistic biological active role, so that controllable drug delivery and tissue function repair effects are realized, and an innovative strategy is provided for comprehensive treatment of drug delivery through skin, mucous membrane and other paths.

Description

Technical Field

[0001] This invention belongs to the field of biopharmaceutical preparations, specifically relating to a near-infrared triggered drug-loaded calcium-based pneumatic microneedle patch, its preparation method, and its application. Background Technology

[0002] Microneedle technology, as an innovative minimally invasive delivery platform, exhibits unique comprehensive advantages when applied to skin and mucous membranes. It can physically puncture the outermost dense stratum corneum of the skin or the mucous barrier and epithelial layer of the mucous membrane, forming reversible micron-level channels, thereby significantly improving the efficiency of local or systemic drug delivery. Compared to traditional drug delivery methods, microneedle delivery avoids gastrointestinal degradation and the first-pass effect of oral formulations, and also reduces the pain associated with injections. This technology combines painless / minimally painless characteristics, patient self-administration, no scarring, and low risk of infection, greatly improving treatment compliance and safety. Furthermore, by precisely designing the microneedle length, drug loading formulation, and release mechanism, it can flexibly achieve a wide range of medical goals, from superficial targeted therapies (such as skin diseases, wounds, oral ulcers, and periodontitis) to deep systemic drug delivery (such as vaccines, hormones, and biologics), providing solutions for the field of percutaneous and mucosal drug delivery.

[0003] Currently, the drug loading and release process of pneumatic microneedles relies on the passive dissolution and diffusion of the needle material, which has limitations: First, the drug release rate is uncontrollable, and the release rhythm is entirely passively dependent on the natural degradation rate of the microneedle substrate. Furthermore, the amount and rhythm of tissue fluid infiltration at the drug delivery site vary from person to person, easily leading to adverse problems such as burst release, delayed release, and imbalances in effective drug delivery duration. Second, traditional pneumatic driving force relies solely on a single in-situ spontaneous acid-base chemical reaction. The gas generation efficiency and pneumatic thrust are easily affected by differential endogenous factors such as the pH, temperature, tissue metabolic state, and individual skin type of the human skin and mucous membrane microenvironment, resulting in extremely poor stability of pneumatic power output and difficulty in ensuring consistent efficacy for batch drug delivery. Third, traditional pneumatic microneedles are all self-triggering gas-release structures with no external controllable on / off switch. Once the microneedle is attached, it automatically starts gas-release, making it impossible to precisely control the start time of the pneumatic reaction and the drug release node as needed. This makes it difficult to adapt to complex individualized clinical treatment scenarios such as staged administration, intermittent administration, and targeted delayed administration, resulting in significant limitations in clinical applicability. Summary of the Invention

[0004] To address the problems existing in the prior art, the present invention aims to provide a near-infrared triggered drug-loaded calcium-based pneumatic microneedle patch, its preparation method, and its application.

[0005] To achieve the above-mentioned objectives, the present invention adopts the following technical solution:

[0006] A near-infrared triggered drug-loaded calcium-based pneumatic microneedle patch includes a backing layer and microneedles located on the backing layer. The microneedles include a microneedle core and a microneedle shell covering the microneedle core. The microneedle shell includes a microneedle framework material, tartaric acid, and a photoinitiator. The microneedle core includes calcium carbonate and a near-infrared photothermal nanomedicine. The near-infrared photothermal nanomedicine is composed of photothermal nanomaterials and a drug.

[0007] The microneedle patch of this invention adopts an integrated shell-core composite structure design. The outer shell of the microneedle includes tartaric acid and a microneedle framework material, while the core of the microneedle is loaded with calcium carbonate-based functional raw materials and photothermal nanomedicine. This patch uses calcium-based materials as the core gas-generating reaction raw material, which undergoes an in-situ chemical reaction with the shell tartaric acid to directionally generate carbon dioxide, constructing a pneumatically driven power source and simultaneously exerting dual core functional advantages. First, the in-situ gas generation forms a controllable pneumatic thrust, providing the core power for drug penetration of the skin and mucous membrane barriers and targeted delivery to deeper lesions. Second, the entire reaction process continuously and sustainably releases active calcium ions, acting in-situ on local defect sites, directly exerting biological activity, effectively synergistically promoting tissue defect repair, and achieving simultaneous enhanced efficacy of drug delivery and repair. Simultaneously, this invention loads photothermal nanomaterials into the microneedle core. Applying near-infrared light externally can stimulate the photothermal nanomaterials in the core to generate heat, triggering internal thermal motion and initiating the calcium carbonate gas generation reaction. This allows for flexible switching between multiple drug release modes, including rapid burst release and long-term stable sustained release, as needed.

[0008] In a preferred embodiment of the present invention, the microneedle matrix material is selected from one or more of hyaluronic acid, sodium alginate, polyvinylpyrrolidone (PVP), polymethyl methacrylate (PMMA), polylactic acid (PLA), polylactic acid-glycolic acid copolymer (PLGA), gelatin, polyvinyl alcohol (PVA) or methacrylamide gelatin (GelMA), preferably gelatin or methacrylamide gelatin (GelMA).

[0009] In a preferred embodiment of the present invention, the photothermal nanomaterial includes one or more of inorganic nanomaterials, organic nanomaterials, or organic-inorganic hybrid composite nanomaterials.

[0010] Preferably, the inorganic nanomaterial is selected from at least one of gold nanorods, gold nanostars, gold nanoshells, carbon nanotubes, graphene oxide, copper sulfide, molybdenum disulfide, tungsten oxide, black phosphorus, Prussian blue, or two-dimensional transition metal carbides (MXene).

[0011] Preferably, the organic nanomaterial is selected from at least one of indocyanine green, benzoporphyrin derivatives, polypyrrole, polyaniline, metal-organic frameworks (MOF), polydopamine, and melanin nanoparticles.

[0012] Preferably, the organic-inorganic hybrid composite nanomaterial is selected from at least one of metal nanorod@polydopamine composite, metal oxide@polydopamine composite, metal sulfide@polydopamine composite, metal oxide@near-infrared photothermal dye composite, MOF@polydopamine composite, and MXene@polydopamine composite.

[0013] The photothermal nanomaterials described in this invention can be obtained commercially or prepared using conventional methods in the field.

[0014] The drugs described in this invention include at least one of baicalin, doxorubicin, metronidazole, emodin, azithromycin, resveratrol, luteolin, apigenin, berberine, or berberine.

[0015] In a preferred embodiment of the present invention, the mass ratio of tartaric acid to calcium carbonate is 10-15:1.

[0016] In a preferred embodiment of the present invention, the photoinitiator is selected from one or more of Irgacure 2959, Eosin Y, or LAP.

[0017] In a preferred embodiment of the present invention, the mass ratio of calcium carbonate to near-infrared photothermal nanomedicine is 1-3:1.

[0018] This invention also provides a method for preparing the above-mentioned near-infrared triggered drug-loaded calcium-based pneumatic microneedle patch, comprising the following steps:

[0019] (1) After dissolving the microneedle skeleton material, tartaric acid and photoinitiator in a solvent, pour the solution into a microneedle mold, cure it by ultraviolet light, and dry it at room temperature to obtain the microneedle shell;

[0020] (2) Mix the photothermal nanomaterials and the drug to obtain near-infrared photothermal nanomedicine; mix calcium carbonate and near-infrared photothermal nanomedicine, add methanol to grind, dry and sieve, pour into the microneedle shell to obtain microneedle body;

[0021] (3) Stir the gelatin solution evenly, fill the backing of the microneedle membrane, cool and dry at room temperature to obtain a near-infrared triggered drug-loaded calcium-based pneumatic microneedle patch.

[0022] In a preferred embodiment of the present invention, in step (1), the solvent includes at least one of deionized water, ethanol, ethanol-water solution, diethylene glycol monoethyl ether, DMSO, dichloromethane or dilute acetic acid aqueous solution.

[0023] In a preferred embodiment of the present invention, the mass concentration of the gelatin solution is 7%-20%.

[0024] This invention also provides the application of the aforementioned near-infrared triggered drug-loaded calcium-based pneumatic microneedle patch in the preparation of drug delivery formulations for skin or mucous membranes. The near-infrared triggered drug-loaded calcium-based pneumatic microneedle patch of this invention possesses pneumatically controlled drug release and deep tissue-targeted penetration capabilities. When applied to the target site on the skin or mucous membrane, it relies on pneumatic synergistic driving to efficiently deliver the loaded drug into the deep tissues of the skin or mucous membrane, increasing the effective retention of the drug in deep lesions. This achieves deep, uniform drug delivery and long-term retention, improving upon existing delivery defects such as insufficient transdermal or mucous membrane delivery depth, low local drug concentration, and limited duration of action on lesions, thereby enhancing the efficiency and therapeutic effect of drug delivery to the skin and mucous membranes.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] This invention provides a near-infrared triggered drug-loaded calcium-based pneumatic microneedle patch. Utilizing a near-infrared controllable triggering core pneumatic reaction, it overcomes the limitations of traditional passive spontaneous drug release in pneumatic microneedles. The pneumatic drug release process can be precisely initiated on demand, effectively avoiding interference from individual differences in the skin and mucous membrane microenvironment on gas generation and drug release behavior. This significantly improves the controllability and stability of drug release timing, release rate, and pneumatic thrust. Based on the in-situ directional gas generation of the core-shell structured calcium acid, an internally controllable pneumatic driving force is constructed, which strongly assists the drug in penetrating the skin and mucous membrane barriers, greatly enhancing the drug's deep penetration ability and effective retention in target tissues, resulting in significantly improved delivery efficiency. Simultaneously, the gas generation process involves the in-situ sustained release of functional calcium ions, achieving efficient and controllable deep pneumatic drug delivery while synergistically exerting bioactive effects, effectively promoting local bone tissue repair and other therapeutic effects. This achieves dual therapeutic effects of controllable drug delivery and tissue function repair, providing an innovative strategy for comprehensive treatment mediated by skin or viscous drug delivery. Attached Figure Description

[0027] Figure 1 This is an appearance diagram of the microneedle patch prepared according to the present invention;

[0028] Figure 2 SEM image of the microneedles prepared in this invention;

[0029] Figure 3 A cross-sectional view of the shell-core structure of the microneedles prepared in this invention;

[0030] Figure 4 3D diagram of the shell-core structure of the microneedles prepared in this invention;

[0031] Figure 5 The mechanical properties characterization diagram of the microneedles prepared in this invention is shown.

[0032] Figure 6 The image shows the aerodynamic properties of the microneedles prepared in this invention.

[0033] Figure 7 Characterization diagram of the skin and mucous membrane puncture performance of the microneedles prepared in this invention;

[0034] Figure 8 SEM image of the microneedles prepared in this invention after being inserted into isolated periodontal mucosa tissue of a rat;

[0035] Figure 9 Fluorescence spectrum characterizing the permeability of the microneedles prepared in this invention;

[0036] Figure 10 A quantitative graph characterizing the permeability of the microneedles prepared in this invention;

[0037] Figure 11 The in vivo retention performance characterization diagram of the microneedles prepared in this invention;

[0038] Figure 12 This is an in vitro release characterization diagram of the microneedles prepared according to the present invention;

[0039] Figure 13 This is a comparison diagram of the pneumatic release of the microneedles prepared in this invention. Detailed Implementation

[0040] The present invention will be further illustrated below through specific embodiments. The following embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the following embodiments.

[0041] Example 1: Preparation of near-infrared triggered drug-loaded calcium-based pneumatic microneedle patch

[0042] Near-infrared photothermal nanomedicine (M-BA-PDA-Ti3C2T) x Preparation of Ti3C2T: LiF powder was weighed and slowly added to a 9 mol / L HCl solution. The mixture was magnetically mixed for 30 min, and Ti3AIC2 was slowly added while stirring. The reaction mixture was then placed in a 45℃ oil bath and stirred for 24 h for etching. After etching, the resulting slurry was repeatedly centrifuged at 5000 rpm until the pH of the supernatant was neutral. The mixture was filtered, and the filtrate was vacuum dried at 50℃ for 12 h to obtain solid powder. The solid powder was then ultrasonically exfoliated to obtain Ti3C2T. x A certain amount of Ti3C2T x Disperse the sample in an appropriate amount of deionized water, adjust the pH to 8.5 with Tris-HCl buffer, add dopamine (DA), stir and react for 24 hours, collect the precipitate by ultracentrifugation, wash three times with deionized water, and freeze-dry to obtain PDA-Ti3C2T. x .

[0043] Weigh out baicalin (BA), dissolve it in methanol, and add it to PDA-Ti3C2T. xThe solution was stirred at room temperature for 24 h. The mixture was centrifuged at 12000 rpm for 8 min, the precipitate was collected, and the product was washed three times with PBS to obtain BA-PDA-Ti3C2T. x Macrophage membranes were obtained using a cyclic extrusion-centrifugation method. (BA-PDA-Ti3C2T) x The mixture was thoroughly mixed with macrophage membranes and extruded through a 400 nm polycarbonate membrane using a liposome extruder. After 15 cycles, near-infrared photothermal nanomedicine—MXene dopamine composite nanoparticles loaded with baicalin (M-BA-PDA-Ti3C2T)—was obtained. x ).

[0044] Weigh 1.5 g GelMA, 250 mg tartaric acid and 25 mg LAP and dissolve them in 10 mL of ultrapure water. Heat the solution in a 50°C water bath and stir until dissolved. Pour the solution into a PDMS microneedle membrane and fill the inner cavity of the microneedle membrane. Centrifuge, remove excess solution, irradiate with ultraviolet light (405 nm) for 1 min to cure, and dry at room temperature for 12 h to obtain a hollow microneedle shell.

[0045] Weigh out 20 mg of CaCO3 and 20 mg of near-infrared photothermal nanomedicine (M-BA-PDA-Ti3C2T) respectively. x The powder was mixed at a mass ratio of 1:1, and an appropriate amount of methanol was added for grinding. After drying, the mixture was sieved, centrifuged, and excess powder was removed to obtain the CaCO3-loaded and near-infrared photothermal nanomedicine (M-BA-PDA-Ti3C2T). x The microneedle body was frozen at -20℃ for 30 min and then prepared for use.

[0046] Prepare 5 mL of 20% gelatin (w / v) solution, stir well, and after slight cooling, fill the backing of the microneedle membrane with 500 μL. Allow to cool and dry at room temperature for 24 h. Peel the microneedles from the mold using adhesive tape to obtain a near-infrared triggered drug-loaded calcium-based pneumatic microneedle patch (MN@Ca / M-BA-PDA-Ti3C2T). x Store in a cool, dark place.

[0047] Example 2: Preparation of near-infrared triggered drug-loaded calcium-based pneumatic microneedle patch

[0048] Preparation of near-infrared photothermal nanomedicine (AuDOX): 20 µL of doxorubicin solution (10 mM) was mixed with 500 µL of sodium citrate solution (38.8 mM), followed by the addition of 500 µL of chloroauric acid solution (2 mM). The mixture was immediately vortexed and allowed to stand at room temperature for several hours to obtain a bright red colloidal solution, thus successfully synthesizing the near-infrared photothermal nanomedicine—gold nanoparticles loaded with doxorubicin (AuDOX).

[0049] Weigh 1.5g GelMA, 200mg tartaric acid and 25mg LAP and dissolve them in 10mL ultrapure water. Heat the solution in a 50℃ water bath and stir until homogeneous. Pour the solution into a PDMS microneedle membrane and fill the inner cavity of the microneedle membrane. Centrifuge, remove excess solution, irradiate with ultraviolet light (405 nm) for 1 min to cure, and dry at room temperature for 12 h to obtain a hollow microneedle shell.

[0050] Weigh 20 mg of CaCO3 and 20 mg of near-infrared photothermal nanomedicine (AuDOX powder) respectively, mix them in a mass ratio of 1:1, add an appropriate amount of methanol to grind, dry and sieve, centrifuge to remove excess powder, and obtain microneedles loaded with CaCO3 and near-infrared photothermal nanomedicine. Freeze at -20℃ for 30 min for later use.

[0051] Prepare 5 mL of 20% gelatin (w / v) solution, stir well, and after slightly cooling, take 500 μL to fill the backing of the microneedle membrane. Cool and dry at room temperature for 24 h, and peel the microneedles from the mold with tape to obtain near-infrared triggered drug-loaded calcium-based pneumatic microneedle patch (MN@Ca / AuDOX). Store at low temperature and protected from light.

[0052] Example 3: Preparation of near-infrared triggered drug-loaded calcium-based pneumatic microneedle patch

[0053] Preparation of near-infrared photothermal nanomedicine (PLT-PDA-DOX): Resting platelets (PLT) were isolated from fresh whole blood and suspended in PBS containing prostaglandin E1 (PGE1) to maintain their resting state. Then, dopamine hydrochloride was mixed with platelets in Tris-HCl buffer (pH 8.5). Through the oxidative self-polymerization of dopamine, a stable polydopamine (PDA) coating was formed on the platelet membrane surface to obtain PLT-PDA. Subsequently, PLT-PDA was gently mixed with doxorubicin (DOX) under light-protected conditions for 2 hours, and centrifuged and washed to obtain near-infrared photothermal nanomedicine—platelet / polydopamine-loaded doxorubicin nanoparticles (PLT-PDA-DOX).

[0054] Weigh 1.5g GelMA, 250 mg tartaric acid and 25 mg LAP and dissolve them in 10 mL of ultrapure water. Heat the solution in a 50℃ water bath and stir until homogeneous. Pour the solution into a PDMS microneedle membrane and fill the inner cavity of the microneedle membrane. Centrifuge, remove excess solution, irradiate with ultraviolet light (405 nm) for 1 min to cure, and dry at room temperature for 12 h to obtain a hollow microneedle shell.

[0055] Weigh 40 mg of CaCO3 and 20 mg of near-infrared photothermal nanomedicine (PLT-PDA-DOX) powder respectively, mix them at a mass ratio of 2:1, add an appropriate amount of methanol to grind, dry and sieve, centrifuge to remove excess powder, and obtain microneedles loaded with CaCO3 and near-infrared photothermal nanomedicine (PLT-PDA-DOX), freeze at -20℃ for 30 min, and set aside for later use;

[0056] Prepare 5 mL of 20% gelatin (w / v) solution, stir well, and after slightly cooling, take 500 μL to fill the backing of the microneedle membrane. Cool and dry at room temperature for 24 h, and peel the microneedles from the mold with tape to obtain near-infrared triggered drug-loaded calcium-based pneumatic microneedle patch (MN@Ca / PLT-PDA-DOX). Store at low temperature and protected from light.

[0057] Example 4:

[0058] The near-infrared triggered drug-loaded calcium-based pneumatic microneedle patch prepared in Example 1 was subjected to appearance and performance characterization tests, and the specific methods are as follows:

[0059] (1) Appearance of microneedles

[0060] The drug-loaded calcium-based pneumatic microneedle patch prepared in Example 1 was photographed, and the results are as follows: Figure 1 As shown, the microneedles are arranged in an 8×8 pattern with neatly arranged needle tips.

[0061] (2) SEM characterization of microneedles

[0062] The morphology of the microneedles in the drug-loaded calcium-based pneumatic microneedle patch prepared in Example 1 was observed using scanning electron microscopy. The results are as follows: Figure 2 As shown, the microneedle has a triangular pyramidal structure with clear and sharp edges.

[0063] (3) Characterization of the shell-core structure of microneedles

[0064] Near-infrared photothermal nanomedicines were constructed by labeling the outer shell of microneedles with DiIC18(3) dye (DiI) and the inner core of the microneedles with coumarin 6 (C6). A Ca-based pneumatic microneedle drug delivery system (DiI / MN@Ca / M-C6-PDA-Ti3C2T) was also constructed to label the DiI and C6-labeled drugs. x The preparation method is as follows:

[0065] C6-labeled near-infrared photothermal nanomedicine (M-C6-PDA-Ti3C2T) x Preparation of BA: Replace BA with C6, and the rest of the preparation method is the same as in Example 1;

[0066] Weigh 1.5 g GelMA, 250 mg tartaric acid, and 25 mg LAP and dissolve them in 10 mL of ultrapure water. Heat in a 50°C water bath to dissolve. Add 100 μL of DiI solution (100 μM), stir well, and pour into a PDMS microneedle membrane, filling the inner cavity of the membrane. Centrifuge (3000 rpm, 3 min), remove excess solution, irradiate with UV light (405 nm) for 1 min to solidify, and dry at room temperature for 12 h to obtain a DiI-labeled hollow microneedle shell.

[0067] Weigh out 20 mg of M-C6-PDA-Ti3C2T respectively x 20 mg of CaCO3 powder was mixed at a mass ratio of 1:1, and an appropriate amount of methanol was added to grind the mixture. After drying, the mixture was sieved, poured into a hollow microneedle shell, centrifuged (3000 rpm, 3 min), and excess powder was removed to obtain the needle body. The needle body was then frozen at -20℃ for 30 min for later use.

[0068] Take 5 mL of the pre-prepared 20% gelatin (w / v) solution, stir well, and pour into the microneedle membrane backing after slight cooling. Allow to dry at room temperature for 24 h. Peel the microneedles from the mold using adhesive tape to obtain the fluorescently labeled microneedles (DiI-MN@Ca / M-C6-PDA-Ti3C2T). x Store in a cool, dark place.

[0069] DiI-MN@Ca / M-C6-PDA-Ti3C2T was observed using laser confocal microscopy. x The core-shell structure of the microneedle was observed. The sample was placed on a glass-bottomed culture dish, and green (core) and red (shell) images were acquired using a laser confocal microscope. CLSM images showed that the red fluorescence signal (DiI) was uniformly distributed in the outer shell of the needle, while the green fluorescence signal (C6) was concentrated in the core. The merged image showed that the fluorescent regions of the shell and core overlapped, appearing yellow. Both cross-sectional and three-dimensional images confirmed the core-shell structure of the microneedle. Figure 3 , Figure 4 ).

[0070] (4) Characterization of the mechanical properties of microneedles

[0071] The mechanical properties of the microneedles were tested using an electronic universal testing machine. The microneedle patch prepared in Example 1 was placed on a steel plate, and the tensile rate was set to 1 mm / min, with a maximum compressive strain of 80%. During the test, the force-displacement curves were recorded, and the results are as follows: Figure 5As shown, the curve flattens out as the displacement increases from 0.2 mm to approximately 0.7 mm, with the peak force remaining low, close to 0 N. This indicates that the microneedle tip is relatively sharp, enabling smooth puncture with minimal initial resistance. Once the displacement exceeds 0.7 mm, the curve slope increases significantly, indicating that the force on the microneedle begins to rise. With further increases in displacement, the microneedle exhibits excellent bending resistance. Throughout the entire test, no structural fracture or tip breakage occurred, demonstrating good mechanical strength and structural stability.

[0072] (5) Characterization of the aerodynamic properties of microneedles

[0073] To investigate the "aerodynamic" response of microneedles driven by the photothermal effect, the following experiment was conducted: First, the drug-loaded calcium-based aerodynamic microneedle patch prepared in Example 1 was cut into strips by a blade. Then, the treated microneedle tips were attached sideways to the side of a circular transparent tape, and the tips were then immersed in a phosphate buffer solution. A near-infrared laser with a wavelength of 808 nm was used as the light source to horizontally irradiate the microneedle tip region immersed in PBS. During near-infrared irradiation (+L), the morphological changes on the surface of the microneedle tips were continuously recorded using a microscope at fixed time intervals (0s, 10s, 20s, 30s, 40s, 50s).

[0074] The pneumatic properties of the microneedles were recorded using microscopic imaging. The results are as follows: Figure 6 As shown, the microneedle (MN@Ca / M-BA-PDA-Ti3C2T) without near-infrared irradiation x The structure remains stable. Microneedles (MN@Ca / M-BA-PDA-Ti3C2T) irradiated with near-infrared light... x The +L) structure expands, generating numerous bubbles and releasing the internal drug. This indicates that the microneedle successfully achieved photothermal-pneumatic drug release.

[0075] (6) Characterization of the puncture performance of microneedles

[0076] The surfaces of isolated rat periodontal teeth and skin tissues were cleaned and disinfected with alcohol. The microneedles prepared in Example 1 were applied to the rat periodontal tissues and skin surfaces, respectively, and pressure was applied for five minutes before removal. Subsequently, the rat periodontal tissues and skin tissues were fixed in 4% paraformaldehyde solution for 24 hours, embedded in paraffin, and H&E-stained sections were prepared for microscopic observation of the microneedle puncture performance.

[0077] The results of microneedle puncture of rat periodontal tissue and skin surface are as follows: Figure 7 China A and Figure 7 As shown in Figure B, the microneedles clearly penetrate the rat's periodontal and skin tissues, forming micropores.

[0078] (7) SEM image of microneedles inserted into isolated periodontal tissue of rats

[0079] Microneedles (MN@Ca / M-BA-PDA-Ti3C2T) x The microneedles were applied to isolated periodontal tissue of rats and irradiated with near-infrared light (+L). The microneedles were then removed and their morphology was observed by SEM. Figure 8 The results showed that the microneedles (MN@Ca / M-BA-PDA-Ti3C2T) without near-infrared irradiation x After being inserted into the rat's periodontal tissue, the needle body partially bends, maintaining the basic structure. The microneedle (MN@Ca / M-BA-PDA-Ti3C2T) was subjected to near-infrared irradiation. x After the +L needle was inserted into the periodontal tissue of the rat, the needle body basically disappeared, indicating that the gas release promoted the separation of the needle body from the backing.

[0080] (8) Characterization of the permeability of microneedles

[0081] DiI+C6 solution: Dilute 1 mM DiI solution and 1 mM C6 solution with pure water to prepare a 100 μM working solution, and store it in the dark for later use.

[0082] DiI-MN@Ca / M-C6-PDA-Ti3C2T x The preparation method is the same as in Example 4 (3).

[0083] DiI+C6 solution and DiI-MN@Ca / M-C6-PDA-Ti3C2T x The drug was administered to isolated rat periodontal tissue, and the microneedle group was irradiated with near-infrared light (+L). Afterward, the microneedles were removed, and the periodontal tissues of both the solution and microneedle groups were fixed in formaldehyde, embedded in OCT, and cross-sectional sections were prepared. Multichannel fluorescence imaging was performed using a microscope. The penetration depth of the DiI / C6 label was measured and quantitatively analyzed. Figure 9 As shown, in the DiI+C6 solution group, only weak DiI fluorescence was observed, with no C6 fluorescence produced. In the DiI-MN@Ca / M-C6-PDA-Ti3C2T solution... x In the tissue sections of group +L, the green fluorescence signal was the strongest, indicating that the drug had successfully penetrated the keratinocytes and entered the deep tissue layer, confirming that the microneedles have pneumatic penetration-enhancing properties.

[0084] Figure 10 Quantitative results showed that the penetration depth of DiI in the DiI+C6 solution group was 31.73 ± 10.39 μm, while C6 showed no penetration. The DiI-MN@Ca / M-C6-PDA-Ti3C2T solution, however, showed no penetration. xThe penetration depths of DiI and C6 in the +L microneedle group were 281.188 ± 11.16 μm and 284.02 ± 13.23 μm, respectively, showing a significant improvement in penetration depth. This verifies that the microneedle has near-infrared light triggering to promote penetration.

[0085] (9) Characterization of the retention properties of microneedles

[0086] C6-labeled microneedles (MN@Ca / M-C6-PDA-Ti3C2T) x Preparation of BA: Replace BA with C6, and follow the same method as in Example 1.

[0087] Preparation of C6 solution: Dilute 1 mM C6 solution with pure water to make 100 μM working solution, and store in the dark for later use.

[0088] MN@Ca / M-C6-PDA-Ti3C2T was administered to the periodontal and oral mucosal tissues of rats. x And C6 solution, and MN@Ca / M-C6-PDA-Ti3C2T x The group performed 808 nm (2 W / cm) 2 Near-infrared light irradiation was performed, and the fluorescence intensity in periodontal tissues was observed using a small animal in vivo imaging system at 0, 4, 8, 12, 24, and 48 h to reflect the dynamic retention of drugs in the periodontal pockets.

[0089] The results are as follows Figure 11 The results showed that the retention time of the C6 solution group was shorter because the retention of C6 solution mainly relies on physical adsorption, which is a weak force and is prone to desorption in the liquid phase, lacking effective tissue anchoring function. MN@Ca / M-C6-PDA-Ti3C2T x The +L group was able to retain the drug in periodontal tissue for more than 48 hours, and its retention stability was significantly higher than that of the C6 solution. This is attributed to the fact that the microneedles can achieve mechanical interlocking with the gingival tissue, and the pneumatic properties of the microneedles promote deep drug penetration, reduce drug clearance, and thus improve the drug retention performance in periodontal tissue.

[0090] (10) In vitro release of microneedles

[0091] Will contain MN@Ca / M-BA-PDA-Ti3C2T xThe microneedle dialysis bag was completely immersed in a container filled with release medium (37°C, pH 7.4 PBS, 0.5% Tween 80). Samples were taken from the external medium at different time points (e.g., 0, 0.5, 1, 2, 4, 8, 12, 24, 36, 48 h), and an equal volume of fresh medium was added. The drug concentration in the samples was determined using high-performance liquid chromatography (HPLC).

[0092] like Figure 12 The display shows that MN@Ca / M-BA-PDA-Ti3C2T x Without near-infrared illumination, the microneedle release rate exhibits a slow release trend. After near-infrared illumination (+L), MN@Ca / M-BA-PDA-Ti3C2T... x The cumulative release of +L increases to about 70% in a short period of time because near-infrared light, as an external stimulus, can trigger the gas-producing reaction of calcium carbonate and tartaric acid through photothermal conversion, accelerate the dissociation of the microneedle structure, and promote drug release.

[0093] (11) Comparison of pneumatic release of microneedles with different structures

[0094] MN@Ca / M-BA-PDA-Ti3C2T x The preparation method is the same as in Example 1.

[0095] Preparation of calcium peroxide pneumatic microneedles (MN@CaO2): Nano-calcium peroxide (CaO2) was mixed with anhydrous ethanol and photocurable polyethylene glycol diacrylate (PEGDA) in a 3:7 ratio to prepare a needle tip masterbatch. Simultaneously, a polyvinyl alcohol (PVA) aqueous solution was prepared as a flexible backing layer. The needle tip masterbatch was filled into a microneedle mold using vacuum injection molding, and air bubbles were removed. Then, the PVA backing solution was injected, followed by irradiation with 365 nm ultraviolet light to cure the PEGDA and form the microneedle structure. After spraying a drug solution onto the microneedle surface, it was rapidly flash-frozen with liquid nitrogen and then dried in a vacuum environment of -40℃ and 0.1 Pa for 4 hours. This process formed a stable drug coating on the microneedle surface while ensuring that the internal CaO2 did not come into contact with moisture and become ineffective during storage.

[0096] The dialysis bag containing microneedles was completely immersed in a container filled with release medium (37°C, pH 7.4 phosphate-buffered saline solution PBS, 0.1% Tween 80). Samples were taken from the external medium at different time points (e.g., 0, 0.5, 1, 2, 4, 8, 12, 24, 36, 48 h), and an equal volume of fresh medium was added. The drug concentration in the samples was determined using high-performance liquid chromatography (HPLC), and the cumulative release at each time point was calculated.

[0097] The experiment compared traditional pneumatic microneedles, represented by calcium peroxide pneumatic microneedles (MN@CaO2), with the microneedles prepared in Example 1 (MN@Ca / M-BA-PDA-Ti3C2T). x The drug release performance of ( ). The results are as follows Figure 13 The results show that MN@CaO2 begins to release immediately upon contact with the release medium, with a cumulative release rate of approximately 70% after 48 hours. MN@Ca / M-BA-PDA-Ti3C2T x No drug release was detected during the first 4 hours without near-infrared light irradiation. After 4 hours, 808 nm near-infrared light irradiation (+L) was applied, and the drug release rate increased sharply. Within 48 hours, 100% of the drug was completely released. The results show that the microneedles prepared in this invention have near-infrared light-triggered controlled release performance.

Claims

1. A near-infrared triggered drug-loaded calcium-based pneumatic microneedle patch, characterized in that, The device includes a backing layer and microneedles located on the backing layer. The microneedles include a microneedle core and a microneedle shell covering the microneedle core. The microneedle shell includes a microneedle framework material, tartaric acid, and a photoinitiator. The microneedle core includes calcium carbonate and a near-infrared photothermal nanomedicine. The near-infrared photothermal nanomedicine is composed of photothermal nanomaterials and a drug.

2. The drug-loaded calcium-based pneumatic microneedle patch according to claim 1, characterized in that, The microneedle matrix material is selected from one or more of polyhyaluronic acid, sodium alginate, vinylpyrrolidone (PVP), polymethyl methacrylate (PMMA), polylactic acid (PLA), polylactic acid-glycolic acid copolymer (PLGA), gelatin, polyvinyl alcohol (PVA), or methacrylamide gelatin (GelMA), preferably gelatin or methacrylamide gelatin (GelMA).

3. The near-infrared triggered drug-loaded calcium-based pneumatic microneedle patch according to claim 1, characterized in that, The near-infrared photothermal nanomaterials include one or more of inorganic nanomaterials, organic nanomaterials, or organic-inorganic hybrid composite nanomaterials.

4. The near-infrared triggered drug-loaded calcium-based pneumatic microneedle patch according to claim 1, characterized in that, The mass ratio of tartaric acid to calcium carbonate is 10-15:

1.

5. The near-infrared triggered drug-loaded calcium-based pneumatic microneedle patch according to claim 1, characterized in that, The photoinitiator is selected from one or more of Irgacure 2959, Eosin Y, or LAP.

6. The near-infrared triggered drug-loaded calcium-based pneumatic microneedle patch according to claim 1, characterized in that, The mass ratio of calcium carbonate to near-infrared photothermal nanomedicine is 1-3:

1.

7. The method for preparing a near-infrared triggered drug-loaded calcium-based pneumatic microneedle patch according to any one of claims 1-6, characterized in that, Includes the following steps: (1) After dissolving the microneedle skeleton material, tartaric acid and photoinitiator in a solvent, pour the solution into a microneedle mold, and cure it by centrifugation and ultraviolet light irradiation, and dry it at room temperature to obtain the microneedle shell; (2) Mix the photothermal nanomaterials and the drug to obtain near-infrared photothermal nanomedicine; mix calcium carbonate and near-infrared photothermal nanomedicine, add methanol to grind, dry and sieve, pour into the microneedle shell to obtain microneedle body; (3) Stir the gelatin solution evenly, fill the backing of the microneedle membrane, cool and dry at room temperature to obtain a near-infrared triggered drug-loaded calcium-based pneumatic microneedle patch.

8. The preparation method according to claim 7, characterized in that, In step (1), the solvent includes at least one of deionized water, ethanol, ethanol-water solution, diethylene glycol monoethyl ether, DMSO, dichloromethane or dilute acetic acid aqueous solution; in step (3), the mass concentration of the gelatin solution is 7%-20%.

9. The use of the near-infrared triggered drug-loaded calcium-based pneumatic microneedle patch according to any one of claims 1-6 in the preparation of formulations for transdermal or mucosal drug delivery.

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