Microneedle with double-layer nested structure and application of microneedle

Abstract

The invention provides a double-layer nested structure microneedle and application thereof, and belongs to the technical field of biomedical materials, the double-layer nested structure microneedle comprises a template microneedle and a nested layer, the nested layer covers the tip of the template microneedle, and the nested layer comprises tea polysaccharide-manganese dioxide polydopamine nanoparticles and a nested layer matrix.

Description

Technical Field

[0001] The invention relates to a double-layer nested structure microneedle and application thereof, belonging to the technical field of biomedical materials. Background Art

[0002] Microneedle (MNs) technology is an innovative drug delivery method that uses micron-sized needles to penetrate the stratum corneum of the skin in an almost non-invasive manner and deliver drugs directly to the dermis. The height of these microneedles is carefully controlled between 100 and 1000 μm to ensure that they can effectively penetrate the stratum corneum without touching the pain nerves, thereby achieving painless drug delivery. Compared with traditional injection methods, microneedle technology is difficult to detect with the naked eye due to its tiny size, which is undoubtedly a great blessing for patients who are afraid of needles. Moreover, the microneedle drug delivery system is easy to operate and can be performed without professional medical staff. It is suitable for home self-administration or community medical services. In addition, the design of the microneedle array enables drugs to penetrate the skin barrier with higher efficiency and act directly on the target area, thereby improving the treatment effect.

[0003] Painless, minimally invasive, efficient and patient-friendly, these advantages of the microneedle drug delivery system have made it a research hotspot in the field of transdermal drug delivery. The microneedle drug delivery system has shown great potential and broad application prospects in the field of transdermal drug delivery systems.

[0004] Alopecia is defined as the loss of hair on the head due to various reasons such as drugs, stress and autoimmune diseases. The negative impact of hair loss is multifaceted, including damaged image, frustrated self-esteem, social and emotional distress, career development and work impact, and mental health problems, which cause great distress to individuals and families. Summary of the invention

[0005] The present invention provides a double-layer nested structure microneedle and application thereof, which can effectively solve the above problems.

[0006] The present invention is achieved in that: A method for preparing tea polysaccharide-manganese dioxide@polydopamine nanoparticles, comprising: At room temperature, the potassium permanganate solution and the tea polysaccharide solution are mixed evenly, and reacted under stirring to obtain a tea polysaccharide-manganese dioxide nanoparticle solution; Add an alkaline aqueous solution with a pH of 8-9.5 to the tea polysaccharide-manganese dioxide nanoparticle solution, mix well, then add a dopamine hydrochloride solution, react under stirring, centrifuge to obtain a precipitate after the reaction is complete, wash the precipitate, and freeze-dry to obtain tea polysaccharide-manganese dioxide@polydopamine nanoparticles.

[0007] Tea polysaccharide-manganese dioxide@polydopamine nanoparticles prepared by the above method.

[0008] A use of the tea polysaccharide-manganese dioxide@polydopamine nanoparticles in the preparation of a drug for promoting hair growth.

[0009] A double-layer nested microneedle comprises a template microneedle and a nested layer, wherein the nested layer covers the tip of the template microneedle and comprises tea polysaccharide-manganese dioxide@polydopamine nanoparticles prepared by the above method and a nested layer matrix.

[0010] A method for preparing the above-mentioned double-layer nested structure microneedle comprises: mixing a polysaccharide derivative, a solvent, a photoinitiator and tea polysaccharide-manganese dioxide@polydopamine nanoparticles to obtain a mixed hydrogel; Placing the mixed hydrogel in a microneedle concave mold, centrifuging to allow the mixed hydrogel to fill the needle cavity in the microneedle concave mold, and removing excess mixed hydrogel; The tip of the template microneedle is aligned with the needle cavity and then inserted into the needle cavity, and then ultraviolet light curing is performed and demoulding is performed to obtain the double-layer nested structure microneedle.

[0011] A use of the above-mentioned double-layer nested structure microneedle, or the double-layer nested structure microneedle prepared by the above-mentioned method in the preparation of a drug for promoting hair growth.

[0012] The beneficial effects of the present invention are: The invention provides a method for preparing tea polysaccharide-manganese dioxide@polydopamine nanoparticles. The prepared nanoparticles have a structure in which polydopamine wraps the surface of the tea polysaccharide-manganese dioxide nanoparticles, and thus can be slowly released in the dermis, thereby achieving the purpose of gradual drug administration, and the released tea polysaccharide-manganese dioxide nanoparticles can remove excessive active oxygen around hair follicles.

[0013] The double-layer nested structure microneedles provided by the present invention can penetrate the dermis and remain in the dermis after penetrating the dermis. The nested layer includes tea polysaccharide-manganese dioxide@polydopamine nanoparticles, which can remove excessive active oxygen around the hair follicles. At the same time, the mechanical stress of the microneedles can stimulate the hair follicles, thereby promoting hair regeneration.

[0014] The nested layer matrix provided by the present invention is a cross-linked hydrogel of a polysaccharide derivative, which not only has good biocompatibility, but also can become an ideal carrier for drug loading and release. The nested layer matrix has a cross-linked network structure, which can be applied to microneedles to achieve sustained release of drugs. At the same time, the reuse of multiple polysaccharide derivatives will also improve the mechanical strength of the nested layer, and enhance the effect of the double-layer nested structure microneedle piercing the skin.

[0015] The microneedle concave mold and template microneedle provided by the present invention are prepared from acrylic resin by 3D printing technology. The geometric parameters of the template microneedle can be designed according to different hair loss areas, morphologies, and degrees, thereby realizing customization of the microneedle, and has the advantages of manufacturing flexibility and efficient material utilization.

[0016] At the same time, the acrylic resin used in the microneedle matrix is ​​a biocompatible resin. When implanted in a living body or in contact with biological tissue, it can cause an appropriate response and will not cause excessive inflammation, rejection, allergic reactions or other adverse phenomena. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0018] Figure 1 Schematic diagram of the preparation process of the double-layer nested structure microneedle provided in an embodiment of the present invention.

[0019] Figure 2 TPs-MnO provided by the embodiment of the present invention 2 @Particle size distribution of PDA NPs.

[0020] Figure 3 In the figure, (a) is a SEM image of a template microneedle provided in an embodiment of the present invention; (b) is a SEM image of a double-layer nested structure microneedle.

[0021] Figure 4 This is a comparison chart of the hair growth effects on mice treated with different treatments provided in the embodiments of the present invention for 14 days. DETAILED DESCRIPTION

[0022] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the invention claimed for protection, but merely represents the selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0023] The embodiment of the present invention provides a method for preparing tea polysaccharide-manganese dioxide@polydopamine nanoparticles, comprising: At room temperature, the potassium permanganate solution and the tea polysaccharide solution are mixed evenly, and reacted under stirring to obtain a tea polysaccharide-manganese dioxide nanoparticle solution; Add an alkaline aqueous solution with a pH of 8-9.5 to the tea polysaccharide-manganese dioxide nanoparticle solution, mix well, then add a dopamine hydrochloride solution, react under stirring, centrifuge to obtain a precipitate after the reaction is complete, wash the precipitate, and freeze-dry to obtain tea polysaccharide-manganese dioxide@polydopamine nanoparticles.

[0024] A sufficient amount of alkaline aqueous solution is added to provide an alkaline environment to promote the reaction.

[0025] Dopamine hydrochloride can self-polymerize to form PDA under alkaline conditions and wrap around the surface of tea polysaccharide-manganese dioxide.

[0026] In some embodiments, the alkaline aqueous solution is aqueous ammonia or aqueous sodium hydroxide solution.

[0027] In some embodiments, the alkaline aqueous solution is an alkaline buffer solution.

[0028] In some embodiments, the alkaline aqueous solution is Tris buffer or bicarbonate buffer.

[0029] In some embodiments, the mass ratio of potassium permanganate to tea polysaccharides is 0.09-0.2:1.

[0030] Too much potassium permanganate will not result in the reaction to obtain tea polysaccharide-manganese dioxide nanoparticles, while too little potassium permanganate will affect the yield.

[0031] In some embodiments, the mass ratio of dopamine hydrochloride to tea polysaccharides is 0.09-0.2:1.

[0032] Using this mass ratio, the prepared nanoparticles have good stability and uniform particle diameter.

[0033] Too much dopamine hydrochloride will cause the nanoparticles to agglomerate together, while too little dopamine hydrochloride will cause the generated polydopamine to fail to completely wrap the tea polysaccharide-manganese dioxide nanoparticles.

[0034] The embodiment of the present invention provides tea polysaccharide-manganese dioxide@polydopamine nanoparticles prepared by the method described in any one of the above embodiments.

[0035] The nanoparticles are structures in which polydopamine wraps the surface of tea polysaccharide-manganese dioxide nanoparticles. After absorbing interstitial fluid, polydopamine will slowly dissolve, and the wrapped tea polysaccharide-manganese dioxide nanoparticles will also be released, achieving the effect of gradual drug release.

[0036] Tea polysaccharide-modified manganese dioxide nanoparticles can have good biocompatibility and hydrophilicity, and exist uniformly and stably in the solution.

[0037] The released tea polysaccharide-manganese dioxide nanoparticles can remove excessive reactive oxygen species (ROS) around hair follicles.

[0038] The embodiment of the present invention provides a use of the above-mentioned tea polysaccharide-manganese dioxide@polydopamine nanoparticles in the preparation of a drug for promoting hair growth.

[0039] In some embodiments, the application is the use of tea polysaccharide-manganese dioxide@polydopamine nanoparticles in the preparation of a drug for treating hair loss.

[0040] In some embodiments, the application is the application of tea polysaccharide-manganese dioxide@polydopamine nanoparticles in the preparation of a drug for treating androgenic alopecia.

[0041] An embodiment of the present invention provides a double-layer nested structure microneedle, which includes a template microneedle and a nested layer, wherein the nested layer covers the tip of the template microneedle, and the nested layer includes tea polysaccharide-manganese dioxide@polydopamine nanoparticles and a nested layer matrix.

[0042] The nested layer covers the tip of the template microneedle, and the two have overlapping parts to form a double-layer nested structure.

[0043] In some embodiments, the double-layer nested structure microneedle has a conical or quadrangular pyramidal shape. That is, the tip of the template microneedle and the nested layer are both conical, or both are quadrangular pyramidal. Both shapes can effectively penetrate the skin.

[0044] The method of using the double-layer nested structure microneedle is: directly apply the double-layer nested structure microneedle to the hair loss area, press the back plate of the double-layer nested structure microneedle to make the tip of the double-layer nested structure microneedle penetrate the skin, press and hold for 1 min, and then fix and retain for 4-5 min to allow the nested layer to absorb the interstitial fluid and fall off, separate from the template microneedle, and then remove the template microneedle.

[0045] When in use, the double-layer nested structure microneedles can effectively penetrate the skin and reach the dermis. After a period of action, the template microneedles will automatically separate from the nested layer, and the nested layer can remain in the dermis when the template microneedles are removed from the skin.

[0046] The nested layer includes tea polysaccharide-manganese dioxide@polydopamine nanoparticles. As mentioned above, polydopamine will slowly dissolve after absorbing the interstitial fluid, releasing the tea polysaccharide-manganese dioxide nanoparticles wrapped therein, thereby achieving the effect of gradual drug release.

[0047] The released tea polysaccharide-manganese dioxide nanoparticles can remove excess reactive oxygen species (ROS) around the hair follicles. At the same time, the mechanical stress of the microneedles will stimulate the hair follicles. The two work synergistically to promote hair regeneration.

[0048] Compared with traditional drug delivery methods, the use of double-layer nested microneedles reduces the frequency of drug delivery, achieves directional drug delivery, improves the therapeutic effect of drugs, and has great application prospects.

[0049] In some embodiments, the nested layers include a cross-linked hydrogel of a polysaccharide derivative.

[0050] The nested layer is quickly made by mixing a polysaccharide derivative hydrogel with nanoparticles and then curing them through ultraviolet light.

[0051] The application of polysaccharide derivative hydrogels in microneedles can achieve the sustained release effect of drugs or nanoparticles.

[0052] After the nested layer reaches the dermis, the cross-linked hydrogel of the polysaccharide derivative will gradually dissolve first, followed by the step-by-step release of the tea polysaccharide-manganese dioxide@polydopamine nanoparticles, thereby further achieving the effect of controlling the drug release time.

[0053] In some embodiments, the polysaccharide derivative is one or more of methacryloyl gelatin, methacryloyl hyaluronic acid, methacryloyl dextran, methacryloyl silk fibroin, and methacryloyl chondroitin sulfate.

[0054] These materials not only have good biocompatibility, but also can become ideal carriers for the loading and release of drugs or nanoparticles.

[0055] The hydrogel material after photocuring using a single polysaccharide derivative has a fast dissolution rate, while the reuse of multiple polysaccharide derivatives will form a mutually cross-linked network structure, while also being able to increase the mechanical strength of the nested layer, thereby enhancing the effect of the double-layer nested structure microneedle penetration into the skin.

[0056] An embodiment of the present invention provides a method for preparing a double-layer nested microneedle as described in any of the above embodiments, comprising: The polysaccharide derivative, solvent, photoinitiator and tea polysaccharide-manganese dioxide@polydopamine nanoparticles are mixed to obtain a hybrid hydrogel; Placing the mixed hydrogel in a microneedle concave mold, centrifuging to allow the mixed hydrogel to fill the needle cavity in the microneedle concave mold, and removing excess mixed hydrogel; The tip of the template microneedle is aligned with the needle cavity and then inserted into the needle cavity, and then ultraviolet light curing is performed and demoulding is performed to obtain the double-layer nested structure microneedle.

[0057] The mixed hydrogel is cured by ultraviolet light to form the nested layer.

[0058] In some embodiments, the photoinitiator is phenyl (2,4,6-trimethylbenzoyl) lithium phosphate (LAP), the polysaccharide derivative is one or more of methacryloyl gelatin (GelMA), methacryloyl hyaluronic acid (HAMA), methacryloyl dextran (DexMA), methacryloyl silk fibroin (SFMA), methacryloyl chondroitin sulfate (CHSMA), and the solvent is phosphate buffered saline (PBS) solution.

[0059] The photoinitiator LAP has good biocompatibility and can quickly initiate the curing of photosensitive hydrogel materials under blue light (wavelength 405nm), making it suitable for the field of biocompatible materials.

[0060] The use of PBS buffer solution can keep the pH value of the mixed hydrogel within its buffer range (usually 7.2-7.4), and can maintain the stability of the nanoparticles so that they are evenly distributed in the solution, thereby improving the reaction efficiency.

[0061] In some embodiments, a polysaccharide derivative having a molecular weight of 200-400 kDa is selected.

[0062] Polysaccharide derivatives have a small molecular weight and are not easy to solidify when irradiated with blue light. If the molecular weight is too large, the solubility is poor, so the medium molecular weight range is generally selected.

[0063] In some embodiments, the mass ratio of the polysaccharide derivative, the PBS buffer solution, and the photoinitiator LAP is 10-20:90-100:0.3-0.7.

[0064] In some embodiments, polysaccharide derivatives, PBS buffer solution, photoinitiator LAP and TPs-MnO 2 The mass ratio of @PDANPs is 10-20:90-100:0.3-0.7:0.01-1.

[0065] The double-layer nested structure microneedles obtained using this formula according to the above preparation method have good formability, high mechanical strength, stable drug loading, simple process, and can be customized and designed for individual hair loss conditions.

[0066] By adjusting the proportion of the polysaccharide derivative component in the nested layer and the specific composition of the polysaccharide derivative component, the swelling and degradation properties of the nested layer matrix in the dermis can be controlled, thereby controlling the release rate of drugs or nanoparticles.

[0067] In some embodiments, the polysaccharide derivatives are GelMA and HAMA.

[0068] In some embodiments, the mass ratio of GelMA to HAMA is 10:1.

[0069] By adjusting the ratio between various polysaccharide derivatives, the degradation time of the nested layer matrix can be controlled.

[0070] In some embodiments, the grafting rate of GelMA is 60%-80%, and the grafting rate of HAMA is 15%-20%.

[0071] By using a polysaccharide derivative with a higher grafting rate, the speed of cross-linking and curing under blue light can be increased, and a cross-linked hydrogel of the polysaccharide derivative with a better molding effect can be obtained.

[0072] In some embodiments, the TPs-MnO 2 The mass fraction of @PDA NPs is 0.01%-1%.

[0073] The drug loading of the nested layers is controllable, and accordingly, the relative proportion of the matrix of the nested layers is also controllable, thereby achieving control of the release rate of the drug or nanoparticles at each tip and the regional drug action amount.

[0074] In some embodiments, the TPs-MnO 2 The mass fraction of @PDA NPs is 0.5%.

[0075] In some embodiments, GelMA, HAMA, photoinitiator LAP and TPs-MnO 2 The mass ratio of @PDA NPs is 200:20:5:0.5.

[0076] In some embodiments, the UV curing time is 10-20 s.

[0077] In some embodiments, the height of the template microneedle is 600-605 μm, the height of the nested layer is 595-600 μm, and the height of the microneedle is 895-905 μm.

[0078] The nested layer covers the tip of the template microneedle to form a nested structure with overlapping parts.

[0079] In some embodiments, the method for preparing the template microneedle comprises: The microneedle concave mold and the template microneedle are obtained by photocuring 3D printing, wherein the microneedle concave mold and the template microneedle respectively include a microneedle matrix, and the microneedle matrix includes an acrylic resin.

[0080] The specific steps of light-curing 3D printing include: (1) By analyzing the area and morphology of hair loss, the geometric parameters of the template microneedle are designed using 3D modeling software, and a microneedle concave mold of corresponding size is designed.

[0081] (2) Use the slicing software that comes with the 3D printer to slice and set the 3D printing parameters and procedures.

[0082] (3) Use acrylic resin as the material for 3D printing.

[0083] (4) Start photocuring 3D printing, and then obtain the microneedle array and the corresponding microneedle concave mold.

[0084] (5) After washing the microneedle array obtained in step (4), the microneedle array is irradiated under ultraviolet light for 2-3 minutes to enhance its mechanical properties and obtain a template microneedle.

[0085] The template microneedles include a backing plate and a tip forming an array.

[0086] The template microneedles prepared by combining 3D printing technology and biocompatible resin have the advantages of manufacturing flexibility, efficient material utilization, significantly shortened R&D cycle and good biocompatibility.

[0087] The 3D printing preparation process is simple and can be customized in size and shape. It is suitable for various regular and irregular skin surfaces and different degrees of hair loss, and can provide customized microneedle design solutions.

[0088] The microneedle matrix and the nested layer matrix are both made of biocompatible resins. When implanted in a living body or in contact with biological tissues, they can cause appropriate responses and will not cause adverse phenomena such as excessive inflammatory reactions, rejection reactions or allergic reactions.

[0089] Furthermore, the acrylic resin used in the microneedle matrix has good biocompatibility, excellent antibacterial properties, corrosion resistance, adjustable physical and chemical properties, and superior processing performance. Compared with other biocompatible resins, it has significant advantages and broad application prospects in the medical and health fields.

[0090] Just choose acrylic resin suitable for 3D light-curing printing.

[0091] In some embodiments, the acrylic resin is one or more of ethylene glycol diacrylate, poly(alkylene) glycol dimethacrylate, methyl methacrylate, and methyl methacrylate.

[0092] An embodiment of the present invention provides the use of the double-layer nested structure microneedle in any of the above embodiments in the preparation of a drug for promoting hair growth.

[0093] The embodiment of the present invention provides the use of a double-layer nested structure microneedle prepared by the method described in any of the above embodiments in the preparation of a drug for promoting hair growth.

[0094] In some embodiments, the application is the use of the double-layer nested structure microneedle in the preparation of a drug for treating hair loss.

[0095] In some embodiments, the application is the use of the double-layer nested structure microneedle in the preparation of a drug for treating androgenic alopecia.

[0096] Example 1 Preparation of double-layer nested microneedles: 1. Preparation of template microneedles and microneedle concave molds: like Figure 1 As shown, the specific steps include: (1) By analyzing the area and morphology of hair loss, the geometric parameters of the template microneedle are designed using 3D modeling software, and a microneedle concave mold of corresponding size is designed.

[0097] The specific geometric parameters of the template microneedle are: height 600 μm, bottom diameter 200 μm, needle spacing 500 μm, array 15×15, 225 tips, and the tip shape is a quadrangular pyramid.

[0098] (2) Use the slicing software that comes with the 3D printer to slice and set the 3D printing parameters and procedures.

[0099] (3) Biocompatible resin purchased from Shenzhen Zongwei Cube Technology Co., Ltd. was used as the 3D printing material. The main components of the resin include caprolactone acrylate, poly (alkylene) glycol dimethacrylate, and polyethylene glycol diacrylate.

[0100] (4) Start photocuring 3D printing, and then obtain the microneedle array and the corresponding microneedle concave mold.

[0101] (5) After washing the microneedle array obtained in step (4), the microneedle array is irradiated under ultraviolet light for 3 minutes to enhance its mechanical properties and obtain a template microneedle.

[0102] 2. Tea polysaccharide-manganese dioxide@polydopamine nanoparticles (TPs-MnO 2 Preparation of @PDA NPs: The specific steps include: (1) Use tea polysaccharides (TPs) extracted from green tea leaves, dissolve TPs in deionized water to prepare a 20 mg / mL solution for later use.

[0103] In addition, 10 mM potassium permanganate (KMnO 4 ) solution, 20 mM, pH=8.8 Tris buffer solution and 1 mg / mL dopamine hydrochloride (DA) solution for later use.

[0104] (2) Take 10 mL of 10 mM KMnO 4 The solution was stirred with 5 mL of 20 mg / mL TPs solution at room temperature for 1 h to obtain TPs-MnO 2 NPs.

[0105] KMnO 4 Will be reduced to MnO by TPs 2 Nanoparticles (NPs) are suspended in the solution and present a colloidal state. At the same time, the solution changes from the original purple-red to yellow-brown, proving that TPs-MnO 2 NPs.

[0106] (3) Add 10 mL of 20 mM Tris buffer solution with a pH of 8.8 to the solution obtained in step (2), and finally add 10 mL of 1 mg / mL DA solution. Stir the mixture in an open container for 24 h. After the reaction is complete, centrifuge the solution at 8000 rpm for 10 min to obtain TPs-MnO 2 @PDA NPs were washed three times with deionized water until the supernatant was colorless, and the lower precipitate was freeze-dried for later use.

[0107] like Figure 2 As shown, it can be seen that the prepared TPs-MnO 2 @The average particle diameter of PDA NPs is around 156.7±2.9 nm.

[0108] 3. Preparation of double-layer nested microneedles: like Figure 1 As shown, the specific steps include: (1) The TPs-MnO prepared above 2 @PDA NPs, phosphate buffer (PBS) solution, methacryloyl gelatin (GelMA), methacryloyl hyaluronic acid (HAMA) and photoinitiator LAP were prepared into a mixed hydrogel with a mass ratio of 0.5:774.5:200:20:5. 2 The concentration of @PDA NPs was 500 μg / mL.

[0109] The grafting rate of GelMA was 65%, and that of HAMA was 18%.

[0110] (2) Inject the mixed hydrogel into the microneedle concave mold prepared above, centrifuge at 4000 rpm for 5 min, and then take it out to ensure that the needle cavity of the mold is completely filled, and scrape off the excess liquid in the mold.

[0111] (3) Align the template microneedle prepared above and press it into the needle cavity of the drug-loaded mold. After adjusting the height of the template microneedle, expose it to ultraviolet light for 20 seconds for curing to form a double-layer nested structure microneedle. The prepared double-layer nested structure microneedle is demolded and taken out.

[0112] 4. Characterization of microneedle morphology: The template microneedles and double-layer nested microneedles prepared above were placed on a sample stage with conductive glue, sprayed with gold, placed in an electron scanning microscope, and the machine was vacuumed. After the machine was stable, the surface morphology of the samples was observed. Figure 3 shown.

[0113] Figure 3 (a) shows the SEM image of the template microneedles, which have a tip height of 600 μm, a base diameter of 200 μm, and a needle spacing of 500 μm. Figure 3 (b) shows the SEM image of a double-layer nested microneedle with a total height of 900 μm, a bottom diameter of 200 μm, and a height of 300 μm for the overlapping part between the nested layer and the template microneedle.

[0114] Compared with the template microneedle, the double-layer nested structure microneedle is taller and has an obvious overlapping structure, indicating that the double-layer nested structure microneedle was successfully prepared.

[0115] Example 2 Evaluation of the efficacy of double-layer nested microneedles in the preparation of drugs that promote hair growth The mice used in the examples of the present invention were C57BL / 6 (male, 6 weeks old).

[0116] After the mice were anesthetized with chloral hydrate (10%), a 1 cm × 1 cm area was shaved on the back of the mice with the dorsal line as the midline using a pet shaver, and depilatory cream was evenly applied. After 5 min, the depilatory cream was washed off with warm water.

[0117] After hair removal, the mice were randomly divided into a model group, a blank microneedle group, and a double-layer nested microneedle group.

[0118] Then, 100 μL of 0.5% testosterone solution (50% ethanol as solvent, w / v) was applied to the hair removal area daily for 28 days (one hair cycle) to inhibit the transition of hair follicles from the resting phase to the growing phase.

[0119] Model group: No additional treatment except daily application of testosterone solution as mentioned above. Topical nanomedicine group: In addition to the daily application of testosterone solution as mentioned above, 100 μL of TPs-MnO was applied to the hair removal area on the 1st, 4th, 7th, 10th and 13th days after hair removal. 2 @PDA (100 μg / mL) solution.

[0120] Blank microneedle group: The difference between the blank microneedle and the double-layer nested structure microneedle in Example 1 is: The nested layers only include the nested layer matrix, and no nanoparticles are loaded in the nested layer matrix.

[0121] Preparation of blank microneedles: The difference from Example 1 is: PBS buffer solution, GelMA, HAMA and photoinitiator LAP were prepared into a mixed hydrogel at a mass ratio of 774.5:200:20:5, wherein the concentration of GelMA was 200 mg / mL.

[0122] The remaining steps are the same as in Example 1.

[0123] In addition to the daily application of testosterone solution mentioned above, a blank microneedle was applied to the hair removal area on the 1st, 4th, 7th, 10th and 13th days after hair removal. The tip of the microneedle was pressed into the skin with the thumb for 1 min, and then removed after 4 min.

[0124] Double-layer nested structure microneedle group: In addition to the daily application of testosterone solution mentioned above, one piece of double-layer nested structure microneedle prepared in Example 1 was applied to the hair removal area on the 1st, 4th, 7th, 10th and 13th days after hair removal, and the tip of the microneedle was pressed into the skin with the thumb for 1 min, and then retained for 4 min before removal.

[0125] like Figure 4 As shown in the figure, on the first day after hair removal, the skin of mice in each group was pink, indicating that the hair follicles in the hair removal area of ​​mice in each group were in a resting period. After different treatments, on the 14th day after hair removal, the mice in the model group did not grow new hair, and their skin remained pink, indicating that the testosterone-induced male induced alopecia mouse model was basically established. The topical nanomedicine group, the blank microneedle group, and the double-layer nested microneedle group all grew hair on the 14th day.

[0126] Compared with the model group, the topical nanomedicine group had a certain hair growth effect, indicating that TPs-MnO 2 @PDA NPs can release TPs-MnO 2 NPs, TPs-MnO 2 NPs can remove excessive reactive oxygen species (ROS) around hair follicles and have a certain hair growth effect.

[0127] Compared with the model group, the blank microneedle group also has a certain hair growth effect. This is because the mechanical stress generated by the blank microneedle during insertion promotes the regeneration of hair follicles.

[0128] The hair density of the double-layer nested structure microneedle group was much greater than that of the other groups on the 14th day, and the treatment effect was very significant, indicating that the double-layer nested structure microneedle has a good effect in treating androgenic alopecia.

[0129] At the same time, the nanomedicine in the double-layer nested structure microneedles and the microneedle drug delivery method have a synergistic effect.

[0130] On the 14th day, ImageJ was used to count the new hair coverage rate of each group, and it was found that the new hair coverage rate of the double-layer nested structure microneedle group (57.57%) was significantly higher than that of the model group (2.2%), the topical nanomedicine group (24.5%) and the blank microneedle group (33.2%).

[0131] The present invention provides a detachable double-layer nested microneedle. Compared with the traditional treatment scheme, the microneedle drug administration method has the advantages of minimally invasive and painless, low drug administration frequency, weak drug dependence, good treatment effect, etc., and solves the embarrassment of users when using it, and greatly eliminates the appearance anxiety caused by the use of microneedles. At the same time, due to the addition of 3D printing technology, the flexibility of microneedle design is greatly enhanced, the material utilization rate is improved, and the preparation cycle is shortened.

[0132] The double-layer nested structure microneedle provided in the embodiment of the present invention utilizes 3D printing technology, which greatly enhances the flexibility of microneedle design, improves material utilization, and shortens the preparation cycle.

[0133] The double-layer nested microneedle structure can improve the patient's acceptance and compliance through the microneedle drug administration method, and its painless and minimally invasive characteristics can avoid the first-pass effect and gastrointestinal degradation of oral drugs, ensuring the bioavailability of drugs. The double-layer nested microneedle structure also achieves precise control and sustained release of drugs, prolongs the drug action time, reduces the frequency of drug administration, has the advantages of weak drug dependence and good therapeutic effect, and provides a more convenient, safe and effective drug administration method for the medical field.

[0134] The material of the double-layer nested structure microneedle has good biocompatibility, reduces the risk of infection, and improves the safety of treatment.

[0135] The nested layers of the double-layer nested microneedles can be completely separated after piercing the dermis, leaving only the nested layers in the dermis. The drug administration process is almost traceless, which solves the embarrassment of users when using it, greatly eliminates the appearance anxiety caused by the use of microneedles, and allows patients to receive treatment in a more relaxed state. This method also allows patients to manage their health conditions more freely in daily life, without frequent visits to medical institutions, reducing the social inconvenience and psychological pressure caused by treatment. This respect for personal privacy and autonomy further enhances patients' confidence and satisfaction in treatment.

[0136] Furthermore, the treatment scheme of the double-layer nested microneedle structure can also be applied to other drugs.

[0137] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for preparing tea polysaccharide-manganese dioxide@polydopamine nanoparticles, characterized in that: include: At room temperature, the potassium permanganate solution and the tea polysaccharide solution are mixed evenly, and reacted under stirring to obtain a tea polysaccharide-manganese dioxide nanoparticle solution; Add an alkaline aqueous solution with a pH of 8-9.5 to the tea polysaccharide-manganese dioxide nanoparticle solution, mix well, then add a dopamine hydrochloride solution, react under stirring, centrifuge to obtain a precipitate after the reaction is complete, wash the precipitate, and freeze-dry to obtain tea polysaccharide-manganese dioxide@polydopamine nanoparticles.

2. Tea polysaccharide-manganese dioxide@polydopamine nanoparticles prepared by the method according to claim 1.

3. Use of the tea polysaccharide-manganese dioxide@polydopamine nanoparticles according to claim 2 in the preparation of drugs for promoting hair growth.

4. A double-layer nested microneedle structure, characterized in that: The double-layer nested structure microneedle comprises a template microneedle and a nested layer, wherein the nested layer covers the tip of the template microneedle, and the nested layer comprises tea polysaccharide-manganese dioxide@polydopamine nanoparticles prepared by the method of claim 1 and a nested layer matrix.

5. The double-layer nested structure microneedle according to claim 4, characterized in that: The nested layers include a cross-linked hydrogel of a polysaccharide derivative.

6. A method for preparing a double-layer nested microneedle according to claim 4 or 5, characterized in that: include: The polysaccharide derivative, solvent, photoinitiator and tea polysaccharide-manganese dioxide@polydopamine nanoparticles are mixed to obtain a hybrid hydrogel; Placing the mixed hydrogel in a microneedle concave mold, centrifuging to allow the mixed hydrogel to fill the needle cavity in the microneedle concave mold, and removing excess mixed hydrogel; The tip of the template microneedle is aligned with the needle cavity and then inserted into the needle cavity, and then ultraviolet light curing is performed and demoulding is performed to obtain the double-layer nested structure microneedle.

7. The method according to claim 6, characterized in that The mass fraction of the tea polysaccharide-manganese dioxide@polydopamine nanoparticles in the mixed hydrogel is 0.01%-1%.

8. The method according to claim 6, characterized in that The photoinitiator is phenyl (2, 4, 6-trimethylbenzoyl) lithium phosphate, the polysaccharide derivative is one or more of methacryloyl gelatin, methacryloyl hyaluronic acid, methacryloyl dextran, methacryloyl silk fibroin, and methacryloyl chondroitin sulfate, and the solvent is a phosphate buffer solution.

9. The method according to claim 6, characterized in that include: The method for preparing the template microneedle comprises: The microneedle concave mold and the template microneedle are obtained by photocuring 3D printing, wherein the microneedle concave mold and the template microneedle respectively include a microneedle matrix, and the microneedle matrix includes an acrylic resin.

10. Use of the double-layer nested structure microneedle according to claim 4 or 5, or the double-layer nested structure microneedle prepared by the method according to any one of claims 6 to 9 in the preparation of a drug for promoting hair growth.

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