A polypeptide composite microneedle array and a preparation method and application thereof
By designing a separable bilayer peptide microneedle array and combining it with photothermal responsive materials, a safe and convenient transdermal drug delivery system was achieved. This system solves the discomfort and infection risks associated with traditional peptide injections, enabling precise dose delivery and long-term drug sustained release, and is suitable for the treatment of diabetes.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- ZHONGDA HOSPITAL SOUTHEAST UNIV
- Filing Date
- 2026-04-09
- Publication Date
- 2026-07-14
AI Technical Summary
Existing oral antidiabetic drugs and subcutaneous injected peptides degrade rapidly in the body, requiring frequent administration, which causes patient discomfort. Furthermore, traditional invasive injections carry risks such as skin infection, nodules, and hypertrophic scarring.
A polypeptide composite microneedle array was designed, employing a separable bilayer structure containing a polypeptide-loaded hydrogel needle tip and needle base. Combined with a photothermal responsive material, the needle base melts and separates under near-infrared light irradiation, enabling precise drug delivery through the microneedles. The needle tip is left in the skin to simulate endogenous hormone supplementation, while simultaneously loading antimicrobial peptides to prevent infection.
It enables safe, simple, and minimally invasive transdermal drug delivery, reduces drug waste, ensures accurate dosage delivery, lowers the trauma risk of traditional injections, and effectively regulates blood sugar, reduces the risk of infection, and provides long-lasting drug release through the synergistic effect of the dual-layer structure.
Smart Images
Figure CN122376734A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of biomedical materials, specifically relating to a polypeptide composite microneedle array, its preparation method, and its application. Background Technology
[0002] Diabetes mellitus (DM) is a global metabolic disease characterized by severe hyperglycemia caused by dysfunction of pancreatic beta cells. Various antidiabetic drugs have been developed to slow disease progression. While oral antidiabetic drugs and subcutaneous injections of active peptides are effective in regulating blood sugar levels, supplementation with exogenous peptides is a more natural approach. This method mimics endogenous hormones such as insulin, glucagon-like peptide-1 (GLP-1), and incretin (GIP). However, these peptides degrade rapidly in the body, requiring frequent administration, leading to patient discomfort and reduced adherence. Furthermore, traditional invasive injections carry risks of skin infection, nodules, hypertrophic scarring, and other complications.
[0003] Therefore, developing safe, effective, and innovative peptide delivery platforms to promote the application of peptide drugs in the treatment of diabetes remains a crucial task. Summary of the Invention
[0004] To address the shortcomings of existing technologies, the present invention aims to provide a polypeptide composite microneedle array, its preparation method, and its application, thereby solving the problems in the prior art.
[0005] The objective of this invention can be achieved through the following technical solutions: A polypeptide composite microneedle array, wherein the microneedle array has a separable bilayer structure, including a connected tip portion and a base portion; The needle tip portion comprises a first hydrogel matrix and a first polypeptide loaded in the first hydrogel matrix; The needle base portion comprises a second hydrogel matrix and a second polypeptide loaded in the second hydrogel matrix; The microneedle array is also loaded with photothermal responsive material; The second hydrogel matrix is configured to melt upon irradiation with near-infrared light by absorbing the heat generated by the photothermal responsive material, thereby causing the base portion of the needle to separate from the tip portion.
[0006] Furthermore, the photothermal responsive material is selected from one or more combinations of black phosphorus nanosheets, black phosphorus quantum dots, gold nanomaterials, graphene, carbon nanotubes, polypyrrole, polyaniline, polydopamine, and PNIPAM-type hydrogels.
[0007] Furthermore, the first hydrogel matrix is selected from one or more combinations of silk fibroin, polyethylene glycol diacrylate, methacrylate gelatin, carboxymethyl cellulose, hyaluronic acid, polylactic acid-glycolic acid copolymer, galactose, dextrin, maltose, polylactic acid, polyvinylpyrrolidone, polyvinyl alcohol, and polydimethylsiloxane. The second hydrogel matrix is selected from one or a combination of two of gelatin and agarose.
[0008] Further, the first polypeptide is selected from one or more combinations of insulin and its analogues that have glucose and lipid metabolism regulation effects, glucagon-like peptide-1 receptor agonists, and glucagon-like peptide / glucose-dependent insulinotropic peptide dual receptor agonists. The second polypeptide is selected from one or more combinations of defensins, taeniacin, melitin, cephalosporin, fruit fly venom, thiocyanate, nisin, or subtilisin, which have antibacterial effects.
[0009] Furthermore, the needle tip portion comprises methacrylate gelatin, black phosphorus quantum dots, and human insulin; the needle base portion comprises gelatin, agarose, and cephalosporin A, which has antibacterial properties.
[0010] Furthermore, the microneedles in the microneedle array are conical in shape and arranged in an orderly manner; the root radius of the microneedles in the microneedle array is 50-500µm, the length is 200-950µm, and the spacing between adjacent microneedles is 200-950µm.
[0011] The above-mentioned method for preparing the polypeptide composite microneedle array includes the following steps: S1, a polymer template for fabricating microneedle arrays; S2, prepare a needle tip precursor solution containing the first polypeptide and the first hydrogel matrix, drop the needle tip precursor solution onto the surface of the polymer template to fill the pores of the polymer template, and then solidify to obtain the needle tip portion; S3, prepare a needle base precursor solution containing the second polypeptide and the second hydrogel matrix, drop the needle base precursor solution onto the surface of the polymer template on which the needle tip portion has been formed, so that the needle base precursor solution fills the base portion of the polymer template, and then solidifies to obtain the needle base portion; S4, peel off from the polymer template to obtain a separable bilayer microneedle array; In S2 and / or S3, the photothermal responsive material is added to the tip precursor solution or the base precursor solution.
[0012] Furthermore, the material of the polymer template is selected from one or more combinations of: polydimethylsiloxane, ethoxylated trimethylolpropane triacrylate, polyethylene glycol diacrylate, and polyethylene glycol methyl methacrylate.
[0013] Furthermore, in S2 and S3, the needle tip precursor solution or the needle base precursor solution is fully filled into the pores and substrate portion of the polymer template by vacuuming or centrifugation; the curing is photopolymerization, drying or thermal curing.
[0014] The above-mentioned polypeptide composite microneedle array is used in the preparation of transdermal drug delivery products for the treatment of metabolic diseases such as diabetes.
[0015] The beneficial effects of this invention are: 1. This invention obtains the microneedle array master structure through 3D printing and prepares a polymer template. Subsequently, a hydrogel precursor solution containing peptides is used to fill the gaps at the needle tips and bases of the template stepwise and sequentially, followed by curing and demolding. This mold replication scheme based on the hydrogel master structure makes the preparation method simple, easy to operate, and inexpensive. At the same time, the polymer template is reusable, greatly reducing production costs, and allows for very easy and precise control of the morphology of the microneedle array.
[0016] 2. This invention designs the microneedle as a separable bilayer structure with a combined tip and base, and introduces photothermal responsive materials (such as black phosphorus quantum dots) into the system. During use, after the microneedle is inserted into the skin, near-infrared light irradiation triggers a thermal effect, causing the base of the microneedle to melt, thus detaching the tip and leaving it in the skin model / body. This "active phase change separation" mechanism significantly shortens the patch wearing time required by the patient, minimizes drug waste in the substrate, and ensures precise dosage delivery. Simultaneously, because only the tip remains in the body, it avoids the trauma of traditional injections, achieving safe, simple, and painless minimally invasive transdermal drug delivery, and possessing the practicality of long-term drug administration and sustained drug release.
[0017] 3. This approach employs differentiated loading within a bilayer structure: a first peptide (such as insulin) with glucose and lipid metabolism regulating effects is loaded into the hydrogel that solidifies to form the needle tip, while a second peptide with antibacterial activity is loaded into the hydrogel that solidifies to form the needle base. This spatial colonization approach not only mimics endogenous hormone supplementation to effectively regulate blood sugar but also utilizes the surface antimicrobial peptide to directly combat local bacterial infections caused by microneedle penetration. The combined use of these two approaches produces a synergistic effect in diabetes treatment, resolving the issues of skin infections and complications that are easily caused by traditional invasive injections, and achieving safer and more efficient on-demand drug delivery. Attached Figure Description
[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0019] Figure 1 This is a schematic diagram of the preparation process of the polypeptide composite microneedle array of the present invention; Figure 2 This is a physical image of a polypeptide composite microneedle array obtained by replicating a polymer template. Figure 3 It is the temperature change displayed by thermal imaging of a microneedle array under near-infrared light irradiation; Figure 4 These are fluorescence images of a peptide composite microneedle array inserted into a skin model; Figure 5 It is a FITC-insulin release curve obtained from a specific example; Figure 6 These are images of the antibacterial zone of a polypeptide composite microneedle array. Figure 7 This is a blood glucose change curve obtained by applying a polypeptide composite microneedle array to a diabetic mouse model.
[0020] Wherein: 1-polymer template, 2-needle tip precursor solution, 3-needle base precursor solution. Detailed Implementation
[0021] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0022] The raw materials used in the examples are from the following sources: Ethoxylated trimethylolpropane triacrylate (ETPTA): CAS: 28961-43-5, Sartomer; 2-Hydroxy-2-methylphenylacetone (HMPP): CAS: 7473-98-5, BASF; Gel methacrylate gelatin (GelMA): 900628, Sigma-Aldrich; Black phosphorus quantum dots (BP QDs): XFNANO; Human insulin: CAS: 11061-68-0, Sigma-Aldrich; Gelatin: CAS: 9000-70-8, Sigma-Aldrich; Agarose: CAS: 9012-36-6, Invitrogen; Cecropin A: CAS: 80451-04-3, GL Biochem; FITC-insulin: Sigma-Aldrich.
[0023] Example 1 like Figure 1 As shown, a method for preparing a polypeptide composite microneedle array includes the following steps: (1) Preparation of polymer template 1 A 12 × 12 conical needle tip array (root diameter: 400 μm; height: 750 μm; spacing: 500 μm) was obtained by 3D printing. ETPTA and 1% (v / v) photoinitiator (2-hydroxy-2-methylphenylacetone, HMPP) were added to a 35 mm diameter dish. The mixture was cured under UV light for 60 s. The sample was washed three times each with anhydrous ethanol and ultrapure water for 10 minutes each time to obtain the ETPTA template.
[0024] (2) Fabrication of separable microneedle arrays: like Figure 1 As shown, a separable microneedle array was prepared. A mixed aqueous solution (needle tip precursor solution 2) of 30% (w / v) GelMA, 0.15 mg / mL BP QDs (photothermal responsive material), 0.5 mg / mL human insulin, and 1% (v / v) HMPP (photoinitiator) was prepared and added dropwise to the surface of the ETPTA template prepared in the previous step. The mixture was centrifuged for 15 minutes to ensure the precursor solution fully filled the conical needle tip array of the template, and excess solution was removed. The array was then cured under UV light for 30 seconds.
[0025] Prepare a mixed aqueous solution of 10% (w / v) gelatin, 2.5% (w / v) agarose, and 10 μM Cecropin A (needle base precursor solution 3). Drop the prepared solution onto the surface of an ETPTA template filled with solidified needle tips. After degassing, cure at room temperature to form a microneedle substrate. Demold the resulting microneedles and store them in a sealed container at 4°C.
[0026] Microneedle array morphology as Figure 2 As shown; Figure 2 In the image, A represents the polypeptide composite microneedle array observed under an optical microscope. Figure 2Image B in the image shows the polypeptide composite microneedle array observed under a scanning electron microscope. It can be seen that the optical microscope reveals that the microneedle tips are clearly conical, with a diameter of approximately 400 μm and a height of approximately 750 μm. Scanning electron microscopy (SEM) further confirms that the microneedles are arranged in an orderly manner, possessing a clear tip-base structure and sharp edges sufficient to penetrate the skin.
[0027] Example 2 In this embodiment, to facilitate fluorescence observation and in vitro release testing, the same method as in embodiment 1 was used, except that the human insulin in the needle tip precursor solution was replaced with an equal concentration of FITC-insulin to prepare a microneedle array loaded with FITC-insulin for subsequent testing; and the microneedle separability experiment and peptide release test were performed.
[0028] Before conducting the above experiments, a skin model was constructed using 3% (w / v) agarose gel. The construction process specifically included: weighing agarose powder and adding it to deionized water or PBS at a mass-to-volume ratio of 3% (w / v). After mixing, the mixture was fully dissolved using microwave heating or heating with stirring until the solution was clear, transparent, and free of visible particles. A large-volume heat-resistant container was used during heating to avoid bumping, and the liquid lost due to evaporation was replenished after heating to restore the system to its initial mass. The agarose solution was then cooled to 60°C, poured into a mold to form a 6 mm thick gel layer, and allowed to stand at room temperature for 25 min or at 4°C for 12 min to allow complete gelation, thus obtaining a 3% (w / v) agarose skin simulation model. This model can be used for microneedle insertion, dissolution, drug diffusion, and mechanical evaluation.
[0029] The experimental procedure includes: Microneedles loaded with FITC-insulin were inserted into a skin model and exposed to 808 nm near-infrared light (1.0 W / cm²). 2 (1 minute). Figure 3 As shown, during irradiation, the temperature at the microneedle base reached the melting point, but the highest temperature on the skin surface remained below the threshold that would cause pain or burns.
[0030] The thermal effect causes the base of the microneedle to melt, causing its tip to detach; the detached needle tip remains within the skin model, such as... Figure 4 As shown; Figure 4 In the diagram, A and B represent the top and side views, respectively. It can be seen that the heat generated by the needle tip is effectively transferred to the GA hydrogel at the needle tip-base interface, inducing local melting and allowing the needle tip to precisely detach from the base. When applied to a skin model, the detached needle tip embeds itself within the skin model.
[0031] Furthermore, the thermal effect induces a responsive release of FITC-insulin from the needle tip. The peptide release process is assessed by fluorescence intensity measurement, and the FITC-insulin release curve is shown below. Figure 5 As shown, the MNs group represents the microneedle array without NIR, and the MNs+NIR group represents the microneedle array with NIR. It can be seen that in ten consecutive release cycles, the drug release of the MNs+NIR group was significantly higher than that of the unirradiated control group (MNs group).
[0032] Example 3 In this embodiment, the antibacterial effect of the microneedle array is verified; Antibacterial activity was evaluated using Staphylococcus aureus and Escherichia coli. Both bacteria were multiplied in liquid culture medium, and the bacterial suspension concentration was adjusted to 1 × 10⁻⁶ with physiological saline. 8 CFU mL -1 Dip sterile cotton swabs into the bacterial suspensions and spread them evenly onto Mueller-Hinton agar plates. Simultaneously, add extracts from the PBS-treated control group (Ctrl group) and the MNs+NIR group onto sterile filter paper of the same size, and attach the filter paper to the surface of the inoculated agar plates. Then, incubate these plates under standard conditions for 16 hours and observe the inhibition zones. Figure 6 As shown, in the agar diffusion test, the inhibition zone of the MNs+NIR group was significantly larger than that of the Ctrl group, indicating that it could effectively inhibit bacterial proliferation.
[0033] Example 4 In this embodiment, the effectiveness of the microneedle array is verified through in vitro experiments; A diabetic mouse model was established using 8-10 week old male C57BL / 6 mice. Diabetes was induced by intraperitoneal injection of streptozotocin (STZ) to ablate pancreatic β cells. Mice with hyperglycemia (>16.7 mM) for two consecutive days indicated successful establishment of the diabetic model. Blood glucose fluctuations were continuously monitored after subcutaneous insulin injection (Insulin group) or application of MNs+NIR. Figure 7 As shown, it can be seen that compared with the insulin group, the MNs+NIR group can achieve a similar initial blood glucose reduction effect, and the duration of blood glucose reduction is prolonged, with better blood glucose control than the subcutaneous insulin injection group.
[0034] In the description of this specification, references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.
[0035] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed invention.
Claims
1. A polypeptide composite microneedle array, characterized in that, The microneedle array has a separable double-layer structure, including a connected needle tip portion and a needle base portion; The needle tip portion comprises a first hydrogel matrix and a first polypeptide loaded in the first hydrogel matrix; The needle base portion comprises a second hydrogel matrix and a second polypeptide loaded in the second hydrogel matrix; The microneedle array is also loaded with photothermal responsive material; The second hydrogel matrix is configured to melt upon irradiation with near-infrared light by absorbing the heat generated by the photothermal responsive material, thereby causing the base portion of the needle to separate from the tip portion.
2. The polypeptide composite microneedle array according to claim 1, characterized in that, The photothermal responsive material is selected from one or more combinations of black phosphorus nanosheets, black phosphorus quantum dots, gold nanomaterials, graphene, carbon nanotubes, polypyrrole, polyaniline, polydopamine, and PNIPAM-type hydrogels.
3. The polypeptide composite microneedle array according to claim 1, characterized in that, The first hydrogel matrix is selected from one or more combinations of silk fibroin, polyethylene glycol diacrylate, methacrylate gelatin, carboxymethyl cellulose, hyaluronic acid, polylactic acid-glycolic acid copolymer, galactose, dextrin, maltose, polylactic acid, polyvinylpyrrolidone, polyvinyl alcohol, and polydimethylsiloxane. The second hydrogel matrix is selected from one or a combination of two of gelatin and agarose.
4. The polypeptide composite microneedle array according to claim 1, characterized in that, The first polypeptide is selected from one or more combinations of insulin and its analogues that have glucose and lipid metabolism regulation effects, glucagon-like peptide-1 receptor agonists, and glucagon-like peptide / glucose-dependent insulinotropic peptide dual receptor agonists. The second polypeptide is selected from one or more combinations of defensins, taeniacin, melitin, cephalosporin, fruit fly venom, thiocyanate, nisin, or subtilisin, which have antibacterial effects.
5. The polypeptide composite microneedle array according to claim 1, characterized in that, The needle tip contains methacrylate gelatin, black phosphorus quantum dots, and human insulin; the needle base contains gelatin, agarose, and cephalosporin A, which has antibacterial properties.
6. The polypeptide composite microneedle array according to claim 1, characterized in that, The microneedles in the microneedle array are conical in shape and arranged in an orderly manner; the root radius of the microneedles in the microneedle array is 50-500µm, the length is 200-950µm, and the spacing between adjacent microneedles is 200-950µm.
7. The method for preparing the polypeptide composite microneedle array according to any one of claims 1-6, characterized in that, Includes the following steps: S1, a polymer template for fabricating microneedle arrays; S2, prepare a needle tip precursor solution containing the first polypeptide and the first hydrogel matrix, drop the needle tip precursor solution onto the surface of the polymer template to fill the pores of the polymer template, and then solidify to obtain the needle tip portion; S3, prepare a needle base precursor solution containing the second polypeptide and the second hydrogel matrix, drop the needle base precursor solution onto the surface of the polymer template on which the needle tip portion has been formed, so that the needle base precursor solution fills the base portion of the polymer template, and then solidifies to obtain the needle base portion; S4, peel off from the polymer template to obtain a separable bilayer microneedle array; In S2 and / or S3, the photothermal responsive material is added to the tip precursor solution or the base precursor solution.
8. The method for preparing the polypeptide composite microneedle array according to claim 7, characterized in that, The polymer template material is selected from one or more combinations of: polydimethylsiloxane, ethoxylated trimethylolpropane triacrylate, polyethylene glycol diacrylate, and polyethylene glycol methyl methacrylate.
9. The method for preparing the polypeptide composite microneedle array according to claim 7, characterized in that, In S2 and S3, the needle tip precursor solution or the needle base precursor solution is fully filled into the pores and substrate portion of the polymer template by vacuuming or centrifugation; the curing is photopolymerization, drying or thermal curing.
10. The use of the polypeptide composite microneedle array according to any one of claims 1-5 in the preparation of transdermal drug delivery products for the treatment of metabolic diseases such as diabetes.