A multi-layer Chinese medicine microneedle with controlled sequential release and preparation method thereof

Abstract

The present invention discloses a multilayer Chinese medicine microneedle with controlled sequential release and a preparation method thereof, wherein two-dimensional materials with photothermal effect and dopamine are used to synthesize inner nanoparticles with dual response to light and pH, and inner nanoparticles with dual response to light and pH are used to load monarch Chinese medicine to form inner drug-loaded nanoparticles; weakly acidic materials are mixed with auxiliary Chinese medicine to prepare outer drug-loaded solution; the outer drug-loaded solution is used to fill the microneedle template and solidify and dry to form a needle tip with a cavity; the inner drug-loaded nanoparticles are mixed with a hydrogel solution, filled into the cavity of the needle tip and formed into the base of the needle tip, and solidified to obtain a multilayer Chinese medicine microneedle with controlled sequential release; the monarch Chinese medicine is selected from Chinese medicine for treating skin damage of immune diseases, and the auxiliary Chinese medicine is selected from Chinese medicine for assisting detoxification of immune diseases. The present invention has a better therapeutic effect on skin damage of immune diseases by drug co-delivery.

Description

Technical Field

[0001] The invention relates to the technical field of biomedical materials and skin damage repair, and in particular to a multi-layer Chinese medicine microneedle with controlled sequential release and a preparation method thereof. Background Art

[0002] A microneedle array is a series of complex and fine needle-like micrometer-level structures, which can be hundreds of micrometers to several millimeters in length, and the diameter of the needle body is only tens to hundreds of micrometers. Therefore, the microneedle can pierce the stratum corneum and create a tiny channel directly to the dermis while minimizing damage to the skin. In this way, the drug is delivered to the deeper layers of the skin tissue and promotes the absorption of the drug by the tissue. Therefore, microneedles are regarded as a new type of minimally invasive and almost painless biomedical device, and are increasingly used in medical cosmetology, vaccine injections, and the treatment of common diseases including diabetes and skin diseases. Recently, microneedles have also received widespread attention in the treatment of skin damage to the immune system.

[0003] A Chinese medicine compound is composed of two or more herbs. "Monarch, minister, assistant and messenger" is the principle of Chinese medicine. The drugs that make up the compound can be divided into monarch, minister, assistant and messenger according to their roles in the prescription, which are called monarch, minister, assistant and messenger. Monarch refers to the drug that plays the main therapeutic role for the main symptom in the compound. Minister refers to the drug that assists the monarch drug in treating the main symptom, or mainly treats the concurrent symptoms. Assistant refers to the drug that cooperates with the monarch and minister drugs to treat concurrent symptoms, or inhibits the toxicity of the monarch and minister drugs, or plays an anti-adjuvant role. Messenger refers to the drug that guides the drugs directly to the lesion site, or harmonizes the drugs.

[0004] Chinese herbal compound prescriptions are common in traditional medicine prescriptions. The functions of the monarch, minister, adjuvant and envoy are limited to the therapeutic coordination of each medicine in the prescription itself. However, in modern medicine, with the optimization and development of drug dosage forms, higher requirements are placed on the composition structure of drugs to achieve better therapeutic effects. For example, in the field of Chinese medicine for immune diseases and skin injuries, there is still a need for such a scientific and effective compound medicine. Summary of the invention

[0005] The purpose of the present invention is to provide a multi-layer Chinese medicine microneedle with controlled sequential release and a preparation method thereof, which has a better therapeutic effect on skin damage caused by immune diseases through the combined controlled release delivery of drugs.

[0006] To achieve the above purpose, the technical solution provided by the present invention is:

[0007] A method for preparing a multi-layer Chinese medicine microneedle with controllable sequential release, comprising: using a two-dimensional material with a photothermal effect and dopamine to synthesize a polydopamine coating material with dual responses to light and pH as an inner layer of nanoparticles, and using the inner layer of nanoparticles to load a monarch Chinese medicine to form an inner layer of drug-loaded nanoparticles; using a weakly acidic material and an auxiliary Chinese medicine to mix to prepare an outer layer of drug-loaded solution; filling a microneedle template with the outer layer of drug-loaded solution, curing, and drying to form a needle tip with a cavity; mixing the inner layer of drug-loaded nanoparticles with a hydrogel solution, filling the cavity of the needle tip to form a base of the needle tip, and curing to obtain a multi-layer Chinese medicine microneedle with controllable sequential release; the monarch Chinese medicine is selected from Chinese medicines for treating skin damage caused by immune diseases, and the auxiliary Chinese medicines are selected from Chinese medicines that assist in detoxification of immune diseases.

[0008] In order to optimize the above technical solutions, the specific measures / limitations taken also include:

[0009] The method for preparing inner-layer drug-loaded nanoparticles is as follows: prepare a mixed solution containing a certain concentration of two-dimensional material with photothermal effect and dopamine, add a monarch drug Chinese medicine solution thereto, mix evenly and adjust the pH, centrifuge to obtain a precipitate, freeze-dry, and obtain inner-layer drug-loaded nanoparticles.

[0010] Preferably, in the mixed solution of the two-dimensional material with photothermal effect and dopamine, the concentration of the two-dimensional material with photothermal effect is 0.3-0.8 mg / mL, and the concentration of dopamine is 0.1-0.3 mg / mL. After adding the traditional Chinese medicine solution of the monarch drug, the mixture is mixed to form a solution of 50-300 μg / mL, the pH is adjusted to 7.0-7.5, and centrifuged at 4000rpm-6000rpm for 12-17 minutes. The precipitate is obtained and freeze-dried for 20-30 hours.

[0011] The method for preparing a needle tip with a cavity is as follows: an outer layer drug-loaded solution prepared by mixing a weakly acidic material with an auxiliary Chinese medicine is filled into the needle tip hole of a microneedle template by centrifugation; after drying, the outer layer drug-loaded solution is again filled into the needle tip hole of the template by centrifugation in the same manner and dried; and a needle tip with a cavity is formed by repeated centrifugal filling and drying.

[0012] Preferably, the volume fraction of the weakly acidic material is 10-30%, the auxiliary Chinese medicine is 0.05-0.3 mg / ml, the centrifugation conditions are 5000rpm-7000rpm, 2-5 minutes, the filling volume each time is 100-300μl, and the drying temperature is 35-40°C; in order to avoid shell defects formed after a single filling and drying, a cavity needle tip structure with a complete morphology is formed by at least two filling and drying.

[0013] The method for preparing a multi-layer Chinese medicine microneedle is as follows: the inner layer of drug-loaded nanoparticles are mixed with a hydrogel solution and quickly filled into the cavity of the needle tip of the mold by vacuuming negative pressure to form the base of the needle tip, and a photoinitiator is added to the raw material of the inner layer of the needle tip, which is cured under ultraviolet irradiation and then cured by ultraviolet irradiation for 10-20 seconds. After curing, the multi-layer Chinese medicine microneedle is peeled off from the microneedle template to obtain the multi-layer Chinese medicine microneedle.

[0014] Preferably, the raw material of the inner layer of the needle tip is prepared by adding 1% by volume of a photoinitiator 2-hydroxy-2-methyl-1-phenyl-1-propanone.

[0015] The two-dimensional material with photothermal effect is selected from at least one of black phosphorus quantum dots, black phosphorus nanosheets, transition metal carbon / nitride solution (MXene), molybdenum disulfide quantum dots, graphene quantum dots, and graphene nanosheets.

[0016] The weakly acidic material is selected from at least one of polyvinyl alcohol and hyaluronic acid.

[0017] The main Chinese medicine is selected from at least one of triptolide, triptolide, artemisia annua and its main components, and camptothecin; the auxiliary Chinese medicine is selected from at least one of white peony root, paeoniflorin, licorice, and glycyrrhizic acid.

[0018] The hydrogel is selected from at least one of methacrylate gelatin solution, polyethylene glycol diacrylate, polyethylene glycol methyl methacrylate, silk fibroin, sodium alginate and chitosan.

[0019] The present invention also protects the multi-layer Chinese medicine microneedles with controlled sequential release prepared by the method.

[0020] The present invention also protects the use of the controllable sequentially released multi-layer Chinese medicine microneedles in the preparation of drugs for skin damage caused by immune diseases.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] The present invention provides a microneedle with a more excellent structure that can control the sequential release of traditional Chinese medicine compound ingredients and its application in skin damage. The needle tip of the outer shell layer of the drug-loaded microneedle can quickly dissolve and release the auxiliary drugs carried therein; the nanoparticles in the inner shell layer quickly heat up under the dual stimulation of the pH microenvironment provided by the dissolution of the outer shell layer material and near-infrared light, and trigger the release of the carried drugs.

[0023] Photothermal materials can convert light energy into heat energy under the irradiation of near-infrared light, and have the advantages of large near-infrared extinction coefficient, high photothermal conversion efficiency, simple manufacturing process, low cytotoxicity, and good biocompatibility; polydopamine is produced by self-polymerization of dopamine under alkaline conditions, and polydopamine has good stability, strong adhesion, and excellent biocompatibility. At the same time, polydopamine has both photothermal conversion ability and pH response. The present invention combines the advantages of photothermal materials with the advantages of polydopamine, and is used for the preparation of traditional Chinese medicine compound for skin damage of immune diseases, triggering the release of the drug carried, and having a better controlled release effect.

[0024] The outer layer of the double-layer microneedle structure is made of a quickly dissolving material, which forms a weakly acidic subcutaneous microenvironment after dissolution to stimulate the inner nanoparticles to release the adsorbed drugs. The excellent near-infrared conversion ability of the nanoparticles causes the needle body to heat up under near-infrared control. As the inner hydrogel needle body swells, the drugs carried in the inner layer are slowly released into the deep layers of the skin, achieving multi-drug co-loading and individual control.

[0025] The auxiliary Chinese medicine encapsulated in the double-layer microneedle is released first, creating a subcutaneous microenvironment to reduce stimulation to the skin tissue, which is more conducive to the application of the main medicine in the inner layer; the main medicine is carried in the nanoparticles in the inner core layer, which can control the release and take effect, with a long action time and small side effects.

[0026] The drug-loaded microneedles of the present invention can also ensure the stability of the properties of multiple drugs, controllable release of Chinese medicine compound, simple medication, and convenient use. The multi-responsive microneedles can be used as an excellent compound drug controlled release carrier and applied to skin damage of various immune diseases, such as the treatment of scleroderma, psoriasis, systemic lupus erythematosus, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 This is a schematic diagram of the preparation and structure of a double-layer drug-loaded microneedle with a core-shell structure of the present invention: 1 is a soluble shell material, 2 is an auxiliary Chinese medicine loaded on the shell layer, 3 is a dual-responsive nanoparticle loaded with the main drug, and 4 is a hydrogel material for the inner core layer.

[0028] Figure 2 This is a physical picture of a double-layer core-shell structured Chinese medicine compound microneedle with controlled sequential release according to the present invention.

[0029] Figure 3 It is a bar chart showing the responsive release of the microneedle drug of the present invention.

[0030] Figure 4 HE staining changes of scleroderma lesions on the back of mice treated with drug-loaded microneedles and mice not treated DETAILED DESCRIPTION

[0031] The above contents of the present invention are further described in detail below in the form of embodiments, but this should not be understood as the scope of the above subject matter of the present invention being limited to the following embodiments, and all technologies realized based on the above contents of the present invention belong to the scope of the present invention.

[0032] The experimental methods used in the following examples are all conventional methods unless otherwise specified, and the reagents, methods and equipment used are all conventional reagents, methods and equipment in the technical field unless otherwise specified.

[0033] The present invention uses a soluble material with excellent biocompatibility to load the adjuvant Chinese medicine for synergistic detoxification on the outer layer of the microneedle to form a soluble shell material, and uses drug-carrying multifunctional nanoparticles with photothermal conversion ability to load the "main drug" on the inner layer to form dual-responsive nanoparticles loaded with the main drug, and the nanoparticles are sealed in a swellable hydrogel material; after the microneedle is inserted into the skin, the outer layer material dissolves to release the auxiliary drug first to establish a subcutaneous microenvironment, and the inner layer hydrogel with swelling characteristics quickly swells by controlling the temperature rise through near-infrared irradiation, and the porosity increases. The acidic pH environment formed by the dissolution of the outer layer material triggers the disintegration of the drug-carrying nanoparticles wrapped in the hydrogel, and the slow release of the main drug in the inner layer is controlled by the dual response of near-infrared and pH.

[0034] The radius of the microneedle tip prepared by the invention is 100-400 μm, the length is 300-1000 μm, and the distance between adjacent microneedles is 100-600 μm.

[0035] The present invention is applied to the repair of skin damage including skin damage in the early stage of systemic sclerosis, psoriasis, systemic lupus erythematosus and the like.

[0036] The present invention is further described in detail below in conjunction with specific embodiments:

[0037] Example 1

[0038] A core-shell structure microneedle patch with an outer layer encapsulating paeoniflorin (Pae) ​​and an inner layer loaded with triptolide (TP) is prepared according to the following method:

[0039] Step 1: Synthesis of polydopamine-transition metal carbon / nitride solution (PDA-MXene): MXene is distributed in deionized water at a concentration of 0.5 mg / mL, and 0.2 mg / mL of dopamine hydrochloride is introduced; the resulting solution is stirred at room temperature for 5 minutes, and then mixed with the triptolide alcohol solution to form a solution with a concentration of 100 μg / mL; the mixed solution is stirred for 30 minutes, the pH is adjusted to 7.0-7.5, and the mixed solution is centrifuged at 5000r for 15 minutes to obtain precipitated nanomaterials; the final triptolide-adsorbed nanomaterials are freeze-dried for 24 hours and stored at 4°C.

[0040] Step 2: Prepare the Pae shell layer needle tip: mix 0.16 mg / ml Pae and 20% volume fraction polyvinyl alcohol to make a solution, fill 200 μl of the mixed solution into the needle tip hole of the microneedle template by centrifugation at 6000 rpm for 3 minutes, remove the excess solution and dry it in a 37°C dryer overnight; after drying, fill the cavity with the solution again in the same way and dry it overnight.

[0041] Step 3: Preparation of double-layer microneedle patch: Mix PEGDA (50% v / v), sodium alginate (4% v / v) and the drug-loaded nanoparticles synthesized in step 1 and add 1% volume fraction of photoinitiator 2-hydroxy-2-methyl-1-phenyl-1-propanone, quickly vacuum fill into the mold pretreated in step 2, and then cure by ultraviolet irradiation for 15 seconds. After curing, peel off from the microneedle template to obtain a double-layer microneedle patch, such as Figure 2 shown.

[0042] Example 2 Drug multi-response release experiment of double-layer microneedles loaded with Chinese medicine compound

[0043] The drug-loaded microneedles were immersed in phosphate buffers of pH 7.4 and pH 5.0, respectively. Subsequently, the microneedles with the inner core layer loaded with the monarch drug and the microneedles without drug addition were immersed in phosphate buffer, half of which were not exposed to near-infrared irradiation, and the other half were irradiated with near-infrared light of about 1.2 watts for 10 minutes per hour; the changes in absorbance were measured with an ultraviolet spectrophotometer at 2, 4, 8, 12, 24, 48 and 72 hours, and the drug release was calculated; the measurement results showed that the cumulative release of the drug-loaded inner layer in the environment of simulated acidic outer layer first release and near-infrared control in 72 hours was about 80%, which was significantly higher than the non-near-infrared control group and the two groups under neutral environment. Figure 3 The figure shows the dual control of drug release by near infrared and pH.

[0044] Microneedle-loaded triptolide combined with paeoniflorin is used for early skin sclerosis in mice with scleroderma. The specific application method is as follows:

[0045] A 1 cm2 square area was located on the back of mice, and bleomycin was continuously injected for 28 days to form a scleroderma model, and the mice were randomly divided into six groups. One group did not receive any treatment as the model group, one group was treated with microneedles without drugs plus near-infrared irradiation, and the other groups received microneedle treatments with different components, namely: microneedles with only the main drug added plus near-infrared irradiation; microneedles with only the adjuvant drug added plus near-infrared irradiation: two drugs were added together without near-infrared stimulation; two drugs were added together with microneedles plus near-infrared irradiation. The specific operations of the treated and treated groups were as follows: first, the microneedle was pressed on the skin lesion so that the microneedle penetrated the skin; then, a near-infrared lamp with a power of about 1.2W was used to vertically irradiate the microneedle at a distance of 5 cm above the microneedle; four times a day, each time for 10 minutes, and the microneedle patch was removed and replaced every other day; after 15 days of treatment, the wound skin of each group of mice was sliced ​​and stained to observe the treatment of the mice, such as Figure 4 As shown, it can be seen that the mice treated with Chinese herbal compound controlled-release microneedle therapy recovered much better than those in other groups.

[0046] The microneedle tip of the drug-loaded microneedle is divided into two layers, the outer layer is loaded with soluble materials to release the "adjuvant" drug first, and the inner layer of the hydrogel is loaded with the synthesized PDA-Mxene. The release of the inner layer drug is controlled by light and pH dual response to perform traditional Chinese medicine treatment of skin diseases; the double-layer microneedle is made by the template-assisted method, and the synthesized PDA-Mxene in the inner layer can well prevent the oxidation of Mxene, improve the photothermal conversion ability of the two-dimensional material, and serve as a drug carrier. It heats up rapidly under near-infrared light irradiation, and the PVA in the outer layer of the microneedle dissolves to release mild anti-inflammatory and detoxifying drugs and form a weakly acidic microenvironment, thereby stimulating the inner layer of PDA-Mxene to decompose and release the adsorbed insoluble "king drug" to achieve the effect of controlled sustained release of micro-toxic drugs. The layered microneedle can be used as an excellent multi-drug combined delivery method and applied to a variety of skin injuries, such as the treatment of early skin injuries in systemic sclerosis.

[0047] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Any technician familiar with the profession, without departing from the scope of the technical solution of the present invention, according to the technical essence of the present invention, any simple modification, equivalent replacement and improvement made to the above embodiment still falls within the protection scope of the technical solution of the present invention.

Claims

1. A method for preparing a multi-layer Chinese medicine microneedle with controlled sequential release, characterized in that: A two-dimensional material with photothermal effect and dopamine are used to synthesize a polydopamine-coated material with dual response to light and pH, which is used as inner layer nanoparticles. The inner layer nanoparticles are loaded with the monarch medicine type traditional Chinese medicine to form inner layer drug-loaded nanoparticles; A weakly acidic material is mixed with an auxiliary Chinese medicine to prepare an outer drug-loaded solution; the outer drug-loaded solution is used to fill a microneedle template, solidify, and dry to form a needle tip with a cavity; the inner drug-loaded nanoparticles are mixed with a hydrogel solution, filled into the cavity of the needle tip to form the base of the needle tip, and solidified to obtain a multi-layer Chinese medicine microneedle with controlled sequential release; the main Chinese medicine is selected from Chinese medicine for treating skin damage caused by immune diseases, and the auxiliary Chinese medicine is selected from Chinese medicine for assisting in detoxification of immune diseases; The main Chinese medicine is selected from at least one of triptolide and triptolide; the auxiliary Chinese medicine is selected from at least one of white peony root and paeoniflorin; The weakly acidic material is selected from at least one of polyvinyl alcohol and hyaluronic acid.

2. The method for preparing the multi-layered Chinese medicine microneedle with controlled sequential release according to claim 1, characterized in that: The method for preparing inner-layer drug-loaded nanoparticles is as follows: prepare a mixed solution containing a two-dimensional material with a photothermal effect and dopamine, add a monarch Chinese medicine solution thereto, mix evenly and adjust the pH, obtain a precipitate by centrifugation, and freeze-dry to obtain inner-layer drug-loaded nanoparticles.

3. The method for preparing the multi-layered Chinese medicine microneedle with controlled sequential release according to claim 1, characterized in that: The method for preparing a needle tip with a cavity is as follows: an outer layer drug-loaded solution prepared by mixing a weakly acidic material with an auxiliary Chinese medicine is filled into the needle tip hole of a microneedle template by centrifugation; after drying, the outer layer drug-loaded solution is again filled into the needle tip hole of the template by centrifugation in the same manner and dried; and a needle tip with a cavity is formed by repeated centrifugal filling and drying.

4. The method for preparing the multi-layered Chinese medicine microneedle with controlled sequential release according to claim 1, characterized in that: The method for preparing a multi-layer Chinese medicine microneedle is as follows: inner layer drug-loaded nanoparticles are mixed with a hydrogel solution and quickly filled into the cavity of the needle tip of the mold by vacuuming negative pressure to form the base of the needle tip, and after curing, the multi-layer Chinese medicine microneedle is peeled off from the microneedle template to obtain the multi-layer Chinese medicine microneedle.

5. The method for preparing multi-layered Chinese medicine microneedles with controlled sequential release according to claim 1, characterized in that: The two-dimensional material with photothermal effect is selected from at least one of black phosphorus quantum dots, black phosphorus nanosheets, transition metal carbon / nitride solutions, molybdenum disulfide quantum dots, graphene quantum dots, and graphene nanosheets.

6. The method for preparing multi-layered Chinese medicine microneedles with controlled sequential release according to claim 1, characterized in that: The hydrogel is selected from at least one of methacrylate gelatin solution, polyethylene glycol diacrylate, polyethylene glycol methyl methacrylate, silk fibroin, sodium alginate and chitosan.

7. A multi-layered Chinese medicine microneedle with controlled sequential release prepared by the method according to any one of claims 1 to 6.

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