Preparation method and application of gold-mannose microneedle patch
By preparing gold-mannose microneedle patches, which combine photothermal properties and anti-inflammatory effects, highly efficient antibacterial and healing-promoting effects on diabetic wounds were achieved, solving the problem of difficult-to-treat diabetic wound infections and realizing precise local warming and drug delivery.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- QUFU NORMAL UNIV
- Filing Date
- 2026-06-04
- Publication Date
- 2026-07-24
AI Technical Summary
Skin wounds in diabetic patients are susceptible to Staphylococcus aureus infection, leading to persistent infection and refractory ulcers. Existing treatments suffer from problems such as antibiotic resistance, poor transdermal absorption, and low efficiency of photothermal materials, making it difficult to achieve both high-efficiency antibacterial treatment and rapid repair.
By combining the photothermal properties of gold nanoparticles with the anti-inflammatory and repairing effects of mannose, a gold-mannose microneedle patch was prepared. The active ingredient was delivered transdermally through soluble microneedles, and localized precise heating was achieved under near-infrared irradiation to destroy bacterial biofilms.
It significantly inhibits bacterial proliferation, improves drug delivery accuracy, and significantly accelerates wound closure, solving the problem of healing chronic diabetic wounds.
Smart Images
Figure CN122440818A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of medical biomaterials and wound repair technology, specifically to a method for preparing and applying a gold-mannose microneedle patch. Background Technology
[0002] Diabetic patients, due to metabolic disorders, peripheral neuropathy, and microcirculatory disturbances, often find their skin wounds in a microenvironment characterized by high glucose, hypoxia, chronic inflammation, and weakened immune function. This makes them highly susceptible to pathogenic bacteria such as Staphylococcus aureus, leading to persistent infection, tissue necrosis, and ultimately, slow wound healing, repeated deterioration, and the formation of intractable ulcers. This poses a significant challenge to be addressed in the field of clinical wound repair.
[0003] Current treatments for diabetic wound infections suffer from a series of common and insurmountable drawbacks: long-term use of traditional antibiotics easily induces bacterial resistance and is difficult to completely remove bacterial biofilms within the wound, leading to recurrent infections and difficulty in eradication; conventional topical antibacterial and repair materials have poor transdermal capabilities, failing to effectively penetrate the stratum corneum to reach deeper tissues of the lesion, resulting in low drug delivery efficiency and poor local effects; while photothermal antibacterial materials possess high bactericidal potential, they generally suffer from low photothermal conversion efficiency, poor thermal stability, and poor biocompatibility, making it difficult to achieve deep drug delivery, efficient antibacterial action, and rapid repair in infected wounds, and failing to adapt to the complex pathological microenvironment of diabetic wounds, resulting in slow healing, prolonged non-healing, and unsatisfactory clinical treatment outcomes.
[0004] Therefore, developing a novel microneedle system with efficient photothermal sterilization, good biocompatibility, and strong healing ability is of great value in solving the clinical challenges of diabetic infected wounds. Summary of the Invention
[0005] This invention overcomes the shortcomings of existing technologies and provides a method for preparing and applying a gold-mannose microneedle patch. This invention combines the photothermal properties of gold nanoparticles, the anti-inflammatory and repairing effects of mannose, and the minimally invasive transdermal advantages of soluble microneedles to prepare a novel microneedle patch suitable for diabetic wounds.
[0006] This invention is achieved through the following technical solution: A method for preparing a gold-mannose microneedle patch, characterized by the following steps: (1) Add the gold nanoparticle solution and mannose to the trehalose solution to obtain a mixed solution; (2) The mixed solution is injected into the mold cavity and then subjected to vacuum degassing and drying. (3) A mixed solution of polyvinylpyrrolidone and polyvinyl alcohol is coated on the surface of a mold containing the mixed solution. After drying and demolding, gold-mannose microneedle patch is obtained.
[0007] Furthermore, in step (1), the concentration of gold nanoparticles in the mixed solution is 1.2 mM, and the mass fraction of mannose is 4%.
[0008] Furthermore, in step (3), the mass ratio of polyvinylpyrrolidone to polyvinyl alcohol is 1~1.5:1.
[0009] Further, in step (1), the gold nanoparticle solution is prepared through the following steps: (1) Weigh out sodium citrate, dissolve it in water, heat it to boiling, and add 886 µL of HAuCl4 aqueous solution (24 mM) for the first time and reflux the solution. (2) The solution was cooled, and 886 µL of HAuCl4 aqueous solution (24 mM) was added for the second time. The solution was then refluxed and the reaction was carried out. (3) Add 886 µL of HAuCl4 aqueous solution (24 mM) for the third time, and continue the reflux reaction. After the reaction is completed, add water to make up the volume and cool at room temperature to obtain the prepared gold nanoparticle solution.
[0010] Furthermore, the reflux reaction during the preparation of the gold nanoparticle solution is maintained at 90 °C for 20-30 min.
[0011] On the other hand, the present invention also provides an application of gold-mannose microneedle patch in diabetic wounds.
[0012] Furthermore, the diabetic wound is treated with photothermal antibacterial therapy.
[0013] Furthermore, the gold-mannose microneedle patch is biocompatible, with a hemolysis rate of less than 1% for all red blood cells.
[0014] Furthermore, the gold-mannose microneedle patch is suitable for diabetic wounds caused by Staphylococcus aureus infection. Test results showed that the wound contraction rate of the AM microneedle patch + laser irradiation treatment group was significantly higher, and the healing process was the fastest. The temperature of the wound site receiving near-infrared irradiation could rise to about 45°C within 5 minutes, confirming that the AM microneedle patch combined with laser irradiation has the best healing-promoting effect.
[0015] Furthermore, the antibacterial activity was evaluated using Staphylococcus aureus and Escherichia coli as test strains. The test results showed that under near-infrared light irradiation, the number of bacterial colonies in the aggregated Au NPs and AM microneedle patch groups was significantly reduced, with an antibacterial efficiency of 73.17% against Escherichia coli and 74.11% against Staphylococcus aureus. The beneficial effects of the technical solution provided by this invention are: 1. The AM microneedle patch of the present invention has excellent photothermal heating and photothermal stability performance. It can achieve precise local heating of infected wounds under near-infrared irradiation. Relying on the photothermal effect, it can significantly inhibit the proliferation of Staphylococcus aureus and Escherichia coli, destroy bacterial biofilms, solve the problems of easy drug resistance and incomplete sterilization of traditional antibiotics, and effectively improve the antibacterial treatment effect of infected wounds.
[0016] 2. It adopts soluble microneedles for minimally invasive transdermal delivery, which can effectively penetrate the stratum corneum and accurately deliver active ingredients to the deep layers of the wound, overcoming the shortcomings of low transdermal efficiency and superficial action of topical drugs, and improving the accuracy of local treatment.
[0017] 3. AM microneedle patches integrate photothermal antibacterial, anti-inflammatory repair, and minimally invasive drug delivery. They significantly accelerate wound closure in diabetic wounds infected with Staphylococcus aureus, effectively solving the clinical problems of slow healing and difficulty in repairing chronic diabetic wounds. Attached Figure Description
[0018] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.
[0019] Figure 1 This is a flowchart illustrating the fabrication process of AM microneedle patches. A shows the fabrication process of AM microneedle patches; B is a photograph of the AM microneedle patch.
[0020] Figure 2 The graph shows the photothermal performance test results of the AM microneedle patch. A represents the temperature change of the microneedle patch after continuous irradiation with different powers for 3 minutes; B represents the temperature change at 0.7 W / cm². 2 Temperature changes of the microneedle patch after four repeated irradiations at different power levels; C shows thermal images of the microneedle patch after continuous irradiation at different power levels for 3 minutes.
[0021] Figure 3 The figures show the hemolysis results of Au NPs, mannose, and AM microneedle patches. A shows the hemolysis results of Au NPs aggregated at different concentrations; B shows the hemolysis results of mannose at different mass fractions; and C shows the hemolysis results of AM microneedle patches.
[0022] Figure 4 The images show the bacterial survival rates and colony diagrams of Staphylococcus aureus and Escherichia coli after treatment in different experimental groups. A shows the survival rate and colony diagram of Staphylococcus aureus after treatment in different experimental groups; B shows the survival rate and colony diagram of Escherichia coli after treatment in different experimental groups.
[0023] Figure 5This image shows the healing effects of different experimental groups on Staphylococcus aureus-infected diabetic wounds. A is a flowchart of establishing a diabetic mouse wound infection model; B is an image showing the changes in wounds at different time points in each group treated with different experimental groups; C is the healing traces of wounds at different time points in each group treated with different experimental groups; D is a thermal imaging image of the treatment process for the aggregated AuNPs + laser irradiation and AM microneedle patch + laser irradiation groups; E is a line graph showing the temperature changes during the treatment process for the aggregated AuNPs + laser irradiation and AM microneedle patch + laser irradiation groups; F is an image showing the changes in the microneedle patch after drug administration. Detailed Implementation
[0024] It should be noted that the following detailed descriptions are illustrative and intended to provide further explanation of this application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.
[0025] To enable those skilled in the art to better understand the technical solutions of this application, the technical solutions of this application will be described in detail below with reference to specific embodiments. Unless otherwise specified, experimental conditions not detailed in the embodiments are generally based on conventional conditions or conditions recommended by the reagent company; reagents, consumables, etc., used in the following embodiments can be obtained commercially unless otherwise specified.
[0026] Example 1 1. Preparation of gold nanoparticles (Au NPs) Weigh 32.3 mg of sodium citrate solid powder and add it to 50 mL of ultrapure water in a three-necked flask. Stir mechanically at 1000 rpm until completely dissolved. Heat the flask to boiling in an oil bath at 110 °C, and quickly add 886 µL of HAuCl4 aqueous solution (24 mM). Maintaining boiling, stir continuously at 1000 rpm / min and reflux for 30 min. Cool the solution to 90 °C, and with mechanical stirring at 1000 rpm, quickly add another 886 µL of HAuCl4 aqueous solution (24 mM) and reflux for 30 min. Continue to quickly add a third 886 µL of HAuCl4 aqueous solution (24 mM) and reflux for another 30 min. Maintain the reflux reaction at 90 °C. After the reaction is complete, dilute to 51 mL with ultrapure water, and remove 33 mL to cool at room temperature. This is the prepared gold nanoparticle solution.
[0027] 2. Preparation of gold-mannose microneedle patches 100 µL of Au NPs solution (3.6 mM) and 12 mg of mannose were added to 200 µL of trehalose solution (450 mg / mL), resulting in a final system with a mannose mass fraction of 4% and a gold nanoparticle concentration of 1.2 mM. This mixture was injected into a PDMS microneedle mold cavity, placed in a vacuum degassing device to remove air bubbles, and dried overnight. Finally, a PVP:PVA mixture of 1.2:1 was coated onto the mold surface containing the mixture. After drying and demolding, the gold-mannose microneedle patch (AM microneedle patch) was obtained.
[0028] Photothermal properties of AM microneedle patches 1. Photothermal heating test AM microneedle patches were placed in a 24-well plate, and the power of the 808 nm laser source was adjusted to 0.3 W / cm². 2 0.5 W / cm 2 0.7 W / cm 2 Irradiate continuously for 3 minutes and record the temperature, then plot the temperature rise curve, as shown below. Figure 2 As shown in Figure A, the higher the laser power, the faster the AM microneedle patch heats up and the higher its equilibrium temperature. Simultaneously, images are acquired every 30 seconds using a thermal imager to record the temperature changes of the AM microneedle patch. Figure 2 As shown in Figure C, the AM microneedle patch exhibits concentrated and uniform temperature rise in the light-receiving area, demonstrating excellent localized and precise temperature rise performance.
[0029] 2. Photothermal stability test AM microneedle patches were placed in a 24-well plate, and the power of the 808 nm laser source was adjusted to 0.7 W / cm². 2 Irradiate continuously for 3 minutes, cool to room temperature, and repeat the irradiation process four more times. Record the temperature and plot the temperature change curve, as shown below. Figure 2 As shown in Figure B, the AM microneedle patch exhibits no significant decrease in heating amplitude and equilibrium temperature, and its heating curve shows good repeatability. This indicates that the prepared AM microneedle patch has excellent photothermal stability and can be repeatedly used for photothermal therapy, meeting the clinical needs for repeated drug administration and antibacterial repair.
[0030] Biocompatibility testing After confirming the efficacy of gold nanoparticles and mannose, assessing their biocompatibility is a prerequisite for clinical translation. The biocompatibility of Au NPs, mannose, and AM microneedle patches was evaluated using a hemolysis assay. Deionized water was used as a hypotonic solution to induce hemolysis of erythrocytes as a positive control, while isotonic saline was used as a negative control. Figure 3 The results showed that the hemolysis rate of red blood cells was less than 1%, which meets the safety standards for hemolysis of biomedical materials and has excellent biocompatibility.
[0031] Antibacterial activity of gold-mannose microneedle patches First, single Staphylococcus aureus and Escherichia coli bacteria preserved on solid LB medium were added to 7-8 mL of liquid LB medium and incubated overnight at 37°C. Then, 1-3 mL of the overnight bacterial culture was added to 20 mL of liquid LB medium and incubated on a shaker at 160 rpm for 2-3 hours until OD (Organic Discharge) was reached. 600nm The concentration was 0.3. The materials were divided into six groups (liquid LB medium as blank control, aggregated Au NPs, aggregated Au NPs + laser irradiation, mannose, AM microneedle patches, and AM microneedle patches + laser irradiation) and added to 96-well plates. The plates were irradiated with or without an 808 nm laser for 5 min, followed by incubation at 37°C for 2 h. Then, 1 µL of the mixture was diluted 1000 times with liquid LB medium, and 5 µL was evenly spread onto solid LB medium using a sterile spreader. The plates were incubated upright at 37°C for 30 min, then inverted overnight. Colony growth was observed, and bacterial viability was assessed using the MTT assay. Figure 4 As shown, the number of colonies formed in the aggregated Au NPs and AM microneedle patch groups irradiated with 808nm near-infrared light was significantly lower than that in other control groups, confirming their excellent antibacterial activity. The study calculated the antibacterial efficiency against Escherichia coli to be 73.17% and against Staphylococcus aureus to be 74.11%.
[0032] Healing ability of diabetic wounds infected with Staphylococcus aureus To evaluate the therapeutic effect of microneedling on Staphylococcus aureus-infected skin wounds, a wound model was first established by intraperitoneal injection of streptozotocin (STZ) at a rate of 50 mg / kg for 5 consecutive days, followed by a sustained random blood glucose level exceeding 16.7 mmol / L. A full-thickness circular wound was then created on the dorsal skin and inoculated with Staphylococcus aureus. Figure 5 A) Mice were randomly assigned to six treatment groups (blank control, aggregated Au NPs, aggregated Au NPs + laser irradiation, mannose, AM microneedle patch and AM microneedle patch + laser irradiation); Figure 5 Tables B and C show the changes in wound area at different time points for each group. Quantitative analysis showed that, compared with the other groups, the AM microneedle patch + laser irradiation treatment group had a significantly higher wound contraction rate and the fastest healing process. Furthermore, as shown in Figures B and C... Figure 5 As shown in Figures D and 5E, the temperature of the wound site exposed to near-infrared irradiation can rise to 45°C within 5 minutes. 0 Around C. For example... Figure 5As shown in Figure F, the drug is loaded onto the needle tip, and the needle tip dissolves after administration, demonstrating drug release. Through in vivo experiments on a diabetic mouse model of infected wounds, we confirmed that AM microneedle patches combined with laser irradiation have the best healing-promoting effect.
[0033] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.
Claims
1. A method for preparing a gold-mannose microneedle patch, characterized in that, The following steps are adopted: (1) Add the gold nanoparticle solution and mannose to the trehalose solution to obtain a mixed solution; (2) The mixed solution is injected into the mold cavity and then subjected to vacuum degassing and drying. (3) A mixed solution of polyvinylpyrrolidone and polyvinyl alcohol is coated on the surface of a mold containing the mixed solution. After drying and demolding, gold-mannose microneedle patch is obtained.
2. The method for preparing the gold-mannose microneedle patch according to claim 1, characterized in that, In step (1), the concentration of gold nanoparticles in the mixed solution is 1.2 mM, and the mass fraction of mannose is 4%.
3. The method for preparing the gold-mannose microneedle patch according to claim 1, characterized in that, In step (3), the mass ratio of polyvinylpyrrolidone to polyvinyl alcohol is 1~1.5:
1.
4. The method for preparing the gold-mannose microneedle patch according to claim 1, characterized in that, In step (1), the gold nanoparticle solution is prepared through the following steps: (1) Weigh out sodium citrate, dissolve it in water, heat it to boiling, and add HAuCl4 solution for the first time. Then reflux the solution. (2) Cool the solution, add HAuCl4 aqueous solution for the second time, and reflux the reaction. (3) Add HAuCl4 aqueous solution for the third time, continue the reflux reaction, add water to make up the volume after the reaction is completed, and cool at room temperature to obtain the prepared gold nanoparticle solution.
5. The method for preparing the gold-mannose microneedle patch according to claim 4, characterized in that, The condensation and reflux reaction takes 20-30 minutes.
6. The application of the gold-mannose microneedle patch prepared by any one of claims 1-5 in diabetic wounds.
7. The application according to claim 6, characterized in that, The diabetic wound was treated with photothermal antibacterial therapy.
8. The application according to claim 6, characterized in that, The gold-mannose microneedle patch is suitable for diabetic wounds caused by Staphylococcus aureus infection.