Hydrogel microneedle patch with combined anti-inflammatory and hyperthermia effects, and preparation method and application thereof

Abstract

The application discloses a hydrogel microneedle patch with combined anti-inflammatory and hyperthermia effects, and a preparation method and application thereof. The preparation method comprises the following steps: mixing polydopamine nanoparticles loaded with drugs and a biocompatible material solution containing a photoinitiator to obtain a pre-gel solution; dropping the pre-gel solution into a mold, and then performing drying and blue light crosslinking to obtain the hydrogel microneedle patch. The polydopamine nanoparticles used are excellent photothermal agents, and have a high drug loading rate. The hydrogel microneedle patch can also be subjected to freezing strengthening treatment to improve the mechanical strength, so that the needle tip can effectively penetrate into an intervertebral disc. The hydrogel microneedle patch can effectively inhibit inflammatory reactions. Meanwhile, hyperthermia can improve the level of heat shock proteins in cells and improve the self-protection of the cells. The hydrogel microneedle patch can promote the release of drugs by near-infrared light stimulation, improve the microenvironment, and meanwhile, a suitable temperature can promote the repair of tissues, so that the hydrogel microneedle patch has a good application prospect in the treatment of intervertebral disc degeneration diseases.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of biomedical materials, and particularly relates to a hydrogel microneedle patch with combined anti-inflammatory and hyperthermia effects, and a preparation method and application thereof. BACKGROUND

[0002] Intervertebral disc degeneration (IVDD) is a degenerative disease of the musculoskeletal system, and the incidence rate in people over 50 years old is more than 90%, and shows a trend of younger generation. The apoptosis of cells in the degeneration process causes the loss of the ability of cells to synthesize extracellular matrix (ECM), resulting in ECM imbalance, which can induce inflammatory mediators such as pro-inflammatory cytokines into the intervertebral disc, and can induce inflammatory response and exacerbate IVDD.

[0003] Small molecule drugs show good therapeutic potential in the regeneration and degeneration of intervertebral disc tissue, but the avascular nature of the intervertebral disc may require prolonged oral drug treatment, and it may be a challenge to achieve an effective concentration of the drug in the intervertebral disc. In addition, the microenvironment after IVDD reduces the effect of the heat shock protein of the cells themselves to play a repair role. Therefore, when IVDD occurs, not only is it necessary to improve the efficacy of the drug and improve the inflammatory microenvironment of the damaged site, but it is also necessary to regulate the protein function of the cells themselves at the damaged site, and a drug carrier that can continuously release the drug is also needed to complete the tissue repair. SUMMARY

[0004] In view of the above problems existing in the prior art, the application provides a hydrogel microneedle patch with combined anti-inflammatory and hyperthermia effects, and a preparation method and application thereof. The polydopamine nanoparticles used are excellent photothermal agents with high drug loading rate and other characteristics, and can be used as a drug carrier. After being compounded with a material with good biocompatibility, the drug is rapidly released through photothermal stimulation to improve the inflammatory microenvironment. At the same time, hyperthermia can enhance the function of the heat shock protein of the cells themselves, and improve the resistance to the harsh microenvironment. Under the above synergistic effect, the repair of the biological tissue is accelerated. In addition, the microneedle patch can also be subjected to a freezing strengthening treatment to improve the mechanical strength thereof, so as to ensure that the needle tip can effectively penetrate the annulus fibrosus tissue.

[0005] The technical scheme of the application is as follows:

[0006] The application relates to a preparation method of a hydrogel microneedle patch with combined anti-inflammatory and hyperthermia effects. Polydopamine nanoparticles loaded with a drug are mixed with a biocompatible material solution containing a photoinitiator to obtain a pre-gel solution. The pre-gel solution is dropped into a mold, and then dried and crosslinked by blue light to obtain the hydrogel microneedle patch.

[0007] Preferably, the hydrogel microneedle patch is also subjected to freeze strengthening treatment, specifically: the hydrogel microneedle patch is first placed in a refrigerator at-20℃ for 3-4h, then placed in a-80℃ refrigerator for 3-4h, and finally placed in liquid nitrogen for 1-2h. Freeze strengthening treatment can improve the mechanical strength of the microneedle patch, ensuring that the needle tip can effectively penetrate the intervertebral disc when treating intervertebral disc degeneration.

[0008] Preferably, the preparation method of the drug-loaded polydopamine nanoparticle comprises the following steps:

[0009] (1) After mixing polyether (F127) and mesitylene, they are added to a mixture of water and anhydrous ethanol, stirred for 20-30min, then dopamine hydrochloride Tris solution is added, and stirring is continued for 24-36h. After washing, polydopamine nanoparticles are obtained;

[0010] (2) The polydopamine nanoparticles are added to a drug solution, stirred for 12-24h, and then washed to obtain drug-loaded polydopamine nanoparticles.

[0011] Preferably, in step (1), the mass-volume ratio of polyether and mesitylene is (0.2-0.36) g:(0.2-0.36) mL.

[0012] Preferably, in step (1), the particle size of the polydopamine nanoparticles is 100-200nm.

[0013] Preferably, the drug is diclofenac sodium.

[0014] Preferably, the photoinitiator is lithium phenyl-2,4,6-trimethylbenzoyl phosphinate; and the biocompatible material is methacrylated gelatin.

[0015] Preferably, the mass ratio of the drug to the polydopamine nanoparticles is 1:100.

[0016] Preferably, the drug loading rate of 4mg polydopamine nanoparticles to 40μg drug is 40%-80%.

[0017] Preferably, the mass-volume ratio of the polydopamine nanoparticles to the biocompatible material solution containing the photoinitiator is less than or equal to 0.4%g / mL.

[0018] Preferably, the specific process for preparing the hydrogel microneedle patch from the pre-gel solution is: the pre-gel solution is added dropwise to the mold, vacuum pumping is performed to remove air from the needle tip, and the temperature is maintained at 35-40℃; after the device is vented, the temperature is kept unchanged, air bubbles on the surface of the solution are quickly removed, and the above operation is repeated 3-5 times; then drying, blue light crosslinking for 3-5min, and finally demolding; wherein the wavelength of the blue light source is preferably 405nm.

[0019] The application also relates to a hydrogel microneedle patch with combined anti-inflammatory and thermotherapy effects, which is prepared by the above method and comprises a bottom sheet and microneedles arranged on the top of the bottom sheet, the needle tips of the microneedles can penetrate into tissues to help play a role. The microneedle patch can effectively inhibit inflammatory reactions, and the thermotherapy can increase the level of heat shock proteins in cells and improve the self-protection of cells; the microneedle patch can also be subjected to a freezing strengthening treatment to improve the mechanical strength and ensure that the needle tips can effectively penetrate into annulus fibrosus tissues.

[0020] Preferably, the height of the needle tips of the microneedles of the hydrogel microneedle patch is 500-600 microns, and the diameter of the needle bases is 200-300 microns.

[0021] The application also relates to the use of the hydrogel microneedle patch with combined anti-inflammatory and thermotherapy effects in the preparation of a product for treating intervertebral disc degeneration.

[0022] Preferably, the hydrogel microneedle patch with combined anti-inflammatory and thermotherapy effects promotes the rapid delivery of drugs through external stimulation, regulates the release of drugs, and the thermotherapy promotes the repair of tissues. The microneedle patch combined with thermotherapy can regulate the release of drugs, effectively relieve the inflammatory microenvironment, promote the synthesis of cell matrix, accelerate the deposition of extracellular matrix, inhibit the catabolism of cells, and reduce the loss of cell matrix.

[0023] Preferably, the external stimulation is near-infrared light stimulation, and the power of the near-infrared light is greater than or equal to 1 W / cm 2 , and the irradiation time of the hydrogel microneedle patch is 8-10 minutes.

[0024] The anti-inflammatory and thermotherapy functions of the microneedle patch are verified by the following method: suitable cells are planted on the surface of the microneedle patch, after 7 days of culture, the RNA of all the cells is extracted; after the concentration of the RNA is determined, the RNA is reversely transcribed into cDNA; finally, real-time quantitative polymerase chain reaction (RT-qPCR) is used to verify the gene level in the cells.

[0025] The application has the following beneficial effects:

[0026] (1) The application uses polydopamine nanoparticles as a drug-loaded matrix, the nanoparticles are an excellent photothermal agent, have good biocompatibility, adhesion and a high drug loading rate; the nanoparticles loaded with drugs are combined with a material with good biocompatibility, so that a preparation with good biocompatibility can be prepared;

[0027] (2) The application provides a hydrogel microneedle patch combining anti-inflammatory and hyperthermia effects, which has the advantages of simple preparation method, good stability, use as a drug sustained-release agent, adjustable rapid release of drugs under photothermal stimulation, suitable temperature generated by photothermal effect, improved self-protection ability of cells, resistance to damage of external microenvironment to cells, thus accelerated repair of tissues, and the like. BRIEF DESCRIPTION OF DRAWINGS

[0028] The application will be further described below in combination with the drawings and examples:

[0029] Figure 1 A transmission electron microscope image of polydopamine nanoparticles (PDA) prepared in Example 1;

[0030] Figure 2 Temperature changes of PDA nanoparticles with different concentrations under near-infrared light irradiation;

[0031] Figure 3 A preparation process of the hydrogel microneedle patch;

[0032] Figure 4 Macroscopic images and scanning electron microscope images of the hydrogel microneedle patch;

[0033] Figure 5 A photothermal image of the hydrogel microneedle patch under near-infrared irradiation;

[0034] Figure 6 Release of diclofenac sodium from the hydrogel microneedle patch with or without near-infrared light irradiation;

[0035] Figure 7 is the effect of the hydrogel microneedle patch combining anti-inflammatory and hyperthermia effects on annulus fibrosus cells at a gene level;

[0036] Figure 8 Mechanical property tests of the microneedle patch after freezing treatment or without treatment;

[0037] Figure 9 Macroscopic images of the freeze-strengthened hydrogel microneedle patch after penetrating into annulus fibrosus tissue. DETAILED DESCRIPTION

[0038] In order to make the objectives, technical solutions and advantages of the present application clearer, further detailed description will be made below with reference to the specific embodiments and the accompanying drawings. It should be understood that these descriptions are only exemplary and are not intended to limit the scope of the present application. In addition, in the following description, the description of the known structures and technologies is omitted to avoid unnecessary confusion of the concept of the present application.

[0039] The present application discloses a preparation method of hydrogel microneedle patch combined with anti-inflammatory and hyperthermia effects, comprising the following steps:

[0040] (1) The preparation process of polydopamine nanoparticles is as follows: 0.2-0.36 g of polyether (F127) and 0.2-0.36 mL of mesitylene are mixed and then added to 100-150 mL of a mixed solution of water and anhydrous ethanol (the mass ratio of water to anhydrous ethanol is 1.08:1), stirred for 20-30 min, and then 50-100 mg of a dopamine hydrochloride Tris solution (the mass fraction of the solution is 0.9%) is added and the stirring is continued for 24-36 h. The obtained product is washed with anhydrous ethanol and acetone respectively for three times. Then, the washed particles in the above step are placed in a mixed solution of anhydrous ethanol and acetone with a volume ratio of 2:1, and the washing is continued under ultrasonic condition for 20-30 min, and this step is repeated for 3 times. Finally, the washed particles are freeze-dried for standby use.

[0041] (2) The preparation process of drug-loaded polydopamine nanoparticles is as follows: the polydopamine nanoparticles are added to a drug solution, stirred for 12-24 h, and then centrifuged and washed to obtain drug-loaded polydopamine nanoparticles, and the drug is preferably sodium diclofenac.

[0042] (3) The biocompatible material is methacrylated gelatin, and the preparation process of the pre-gel solution is as follows: the drug-loaded polydopamine nanoparticles are added to a methacrylated gelatin solution containing a photoinitiator to obtain a pre-gel solution; and the photoinitiator is preferably lithium phenyl-2,4,6-trimethylbenzoyl phosphinate.

[0043] (4) The preparation process of the hydrogel microneedle patch is as follows: the pre-gel solution is added dropwise to a mold, vacuum pumping is performed to exhaust the air in the needle tip part, and the temperature is maintained at 35-40℃; after the device is vented, the temperature is kept unchanged, the air bubbles on the surface of the solution are quickly removed, and the above operation is repeated for 3-5 times; then drying, blue light crosslinking, and finally demolding are performed to obtain the hydrogel microneedle patch. The blue light crosslinking is irradiated by a blue light source for 3-5 min, and the wavelength of the blue light source is preferably 405 nm.

[0044] (5) The freeze strengthening process is as follows: the prepared hydrogel microneedle patch is first placed in a refrigerator at-20℃ for 3-4 h, then placed in a refrigerator at-80℃ for 3-4 h, and finally placed in liquid nitrogen for 1-2 h.

[0045] Example 1 Preparation of polydopamine nanoparticles

[0046] 1. Preparation of polydopamine nanoparticles (PDA)

[0047] 0.36 g of polyether (F127) and 0.36 mL of mesitylene were mixed and added to a mixture of 125 mL of water and anhydrous ethanol (mass ratio of water to anhydrous ethanol was 1.08:1). After stirring for 30 min, 60 mg of a dopamine hydrochloride Tris solution (mass fraction of the solution was 0.9%) was added, and stirring was continued for 24 h. The resulting product was washed three times with anhydrous ethanol and acetone, respectively. Then, the washed particles from the above step were placed in a mixed solution of anhydrous ethanol and acetone in a volume ratio of 2:1, and were further washed under ultrasonic conditions for 30 min. This step was repeated three times. Finally, the washed particles were freeze-dried for later use.

[0048] 2. Photothermal performance test

[0049] Different amounts of PDA nanoparticles were added to PBS to obtain different concentrations of solutions (250 pg / mL, 500 pg / mL, 1 mg / mL, 2 mg / mL, and 4 mg / mL). Then, 1 mL of the mixture was added to a cell culture plate, and a temperature rise test was performed under near-infrared light (808 nm, 2 W / cm 2 ) irradiation. The temperature was recorded periodically every 30 s using a visual infrared thermometer.

[0050] The polydopamine nanoparticles prepared above were subjected to transmission electron microscopy (TEM) and photothermal performance characterization, and the relevant characterization analysis results are as follows:

[0051] The TEM image of the polydopamine nanoparticles is shown in Figure 1 The PDA nanoparticles are regular spherical particles with a particle size of 100-200 nm. Irregular pores exist on the non-smooth surface of the PDA particles.

[0052] As shown in Figure 2 , the temperature change of the PDA nanoparticles under near-infrared light irradiation was monitored. The initial temperature was room temperature. The temperature change of the control group (PBS solution) was not obvious before and after near-infrared light irradiation for 10 min. However, the temperature change of the other five groups of mixtures with different PDA concentrations was more significant when the near-infrared light irradiation time was shorter. As the near-infrared light irradiation time was prolonged, the temperature change became smaller and smaller. After near-infrared light irradiation for 10 min, the temperature of the five groups of solutions with different PDA particle concentrations all rose significantly, and the higher the concentration of the PDA particles, the more significant the temperature change. This indicates that the PDA particles have excellent photothermal performance.

[0053] Example 2 Preparation of PDA / GelMA hydrogel microneedle patch

[0054] This example relates to a method for preparing a PDA / GelMA hydrogel microneedle patch, in particular:

[0055] (1) The polydopamine nanoparticles (PDA) were prepared according to the method in Example 1.

[0056] (2) 1.0 g of GelMA solid sponge was added to 10 mL of PBS (phosphate buffer solution), and then placed in a 37°C oven for complete dissolution, followed by the addition of 0.025 g of photoinitiator lithium phenyl-2,4,6-trimethylbenzoylphosphinate to obtain a 10% GelMA (wt / v) solution.

[0057] (3) Next, the PDA prepared in step (1) was mixed into the 1 mL of 10% GelMA (wt / v) solution obtained in step (2) to obtain a pre-gel solution. The pre-gel solution was dropped into a PDMS mold, and next, the PDMS mold was placed in a negative pressure air extraction device, maintaining the temperature at 35°C. After the device was deflated, the temperature was kept constant, and the air bubbles on the surface of the solution were quickly removed, and the above operation was repeated 5 times. Next, drying was carried out at 35°C, and a hydrogel type composite microneedle patch was formed after 5 min of 405 nm blue light crosslinking, and finally demolding was carried out to obtain a PDA / GelMA hydrogel microneedle patch.

[0058] In addition, a comparative sample GelMA hydrogel microneedle patch was also prepared, and the preparation method was as follows: the pre-gel solution was a 10% GelMA (wt / v) solution without doping PDA, and the subsequent step (3) was synchronized.

[0059] Temperature rise test: The hydrogel microneedle patch was added to a cell culture plate, and the temperature rise test was carried out under near-infrared light (808 nm, 2 W / cm 2 ) irradiation conditions, and the temperature was recorded regularly every 30 s with a visual infrared thermometer.

[0060] The preparation process of the hydrogel microneedle patch in step (3) of this example is shown in Figure 3 .

[0061] The macroscopic image of the hydrogel microneedle patch is shown in Figure 4 , the tip of the hydrogel microneedle patch is in the shape of a pyramid, the height is 500-600 μm, and the bottom diameter is 200-300 μm. Due to the addition of PDA nanoparticles, the hydrogel microneedle patch presents an opaque black color.

[0062] The results of the temperature rise test are shown in Figure 5As shown, the temperature of the GelMA hydrogel microneedle patch does not increase significantly after NIR irradiation, while the temperature of the PDA / GelMA hydrogel microneedle patch increases significantly under NIR irradiation. The above shows that the PDA / GelMA hydrogel microneedle patch has excellent photothermal performance.

[0063] Example 3 Preparation of diclofenac sodium / PDA / methacrylated gelatin (DCs / PDA / GelMA) hydrogel microneedle patch

[0064] This example relates to a method for preparing a DCs / PDA / GelMA hydrogel microneedle patch, specifically:

[0065] (1) According to the method in Example 1, polydopamine nanoparticles (PDA) were prepared, 4 mg of PDA was added to the DCs solution and stirred at 37°C for 24 h. Then, the centrifuge tube was placed in the centrifuge at a speed of 14800 rpm for 5 min, and after removing the supernatant, the PDA was washed with deionized water, and this step was repeated 3 times.

[0066] (2) 1.0 g of GelMA solid sponge was added to 10 mL of PBS (phosphate buffer solution), and then placed in a 37°C oven to completely dissolve, followed by the addition of 0.025 g of photoinitiator lithium phenyl-2,4,6-trimethylbenzoylphosphonate to obtain a 10% GelMA (wt / v) solution.

[0067] (3) Then, the drug-loaded PDA washed in step (1) was mixed into the 1 mL of 10% GelMA (wt / v) solution obtained in step (2) to obtain a pre-gel solution. The pre-gel solution was dropped into the PDMS mold, and then the PDMS mold was placed in a negative pressure air extraction device, and the temperature was maintained at 35°C. After the device was deflated, the temperature was kept constant, and the air bubbles on the surface of the solution were quickly removed, and the above operation was repeated 5 times. Then, dry at 35°C, crosslinking under 405 nm blue light for 5 min to form a hydrogel type composite microneedle patch, and finally demolded.

[0068] The mass ratio of PDA:DCs is 100:1, and the mass-volume ratio of PDA to 10% GelMA solution is 0.4% g / mL.

[0069] Drug release test: the DCs / PDA / GelMA hydrogel microneedle patch was soaked in PBS solution, and irradiated with near-infrared light (808 nm, 1 W / cm 2 or 808 nm, 2 W / cm 2) irradiated for 10 min, then the solution was completely aspirated after 50 min interval, and new PBS solution was added, the released DCs were determined by measuring the absorbance of the solution using UV-Vis spectrophotometer. This process was repeated for 8 times.

[0070] The encapsulation efficiency of PDA nanoparticles to DCs was 74 ± 2.6%. Then, the DCs-loaded PDA was prepared into hydrogel microneedle patch. The results of drug release kinetics were shown in Fig. 6, after near-infrared irradiation for 10 min at certain time intervals, obvious release of DCs was observed, indicating that the near-infrared irradiation affected the drug release behavior of the hydrogel microneedle patch, and the release efficiency had near-infrared light power dependence. Figure 6

[0071] Example 4 Functional verification of anti-inflammatory and hyperthermia of hydrogel microneedle patch

[0072] This example relates to the functional verification of hydrogel microneedle patch, the specific steps are as follows:

[0073] The annulus fibrosus cells were planted on the surface of the hydrogel microneedle patch prepared according to the preparation method of Example 3, and the cell number was 50-60 million / group. After the cells were attached to the surface of the hydrogel microneedle patch, the annulus fibrosus cells were treated with a culture medium containing lipopolysaccharide (LPS) for 3 days, then changed to normal complete culture medium for 7 days, and then extracted the RNA in the annulus fibrosus cells. The RNA was extracted by the following steps: adding Trizol, lysing the cells on ice for 15 min, then adding 200 μL chloroform, standing on ice for 15 min, centrifuging at 4°C at 12000 rpm for 15 min; about 400-500 μL of supernatant was added to 500 μL of isopropanol, and stood on ice for 15 min, centrifuged at 4°C at 12000 rpm for 15 min; remove the supernatant, add DEPC water diluted anhydrous ethanol, centrifuge at 4°C at 7500 rpm for 10 min, remove the supernatant and dry; after complete drying, add 10-20 μL of DEPC water, dissolve the RNA thoroughly; determine the RNA concentration of each group.

[0074] The RNA was reversely transcribed into cDNA, and the specific system and conditions are shown in the following table:

[0075] Table 1 Reverse transcription reaction system

[0076]

[0077] Table 2 Reverse transcription reaction conditions

[0078]

[0079] Real-time quantitative polymerase chain reaction (RT-qPCR), the primer sequence of the related target gene is shown in the following table:

[0080] ​Table 3 PCR primer sequences

[0081]

[0082]

[0083] The anti-inflammatory and hyperthermia functions of the hydrogel microneedle patch are shown in FIG. 7 (including 7A-7D). In the pathological condition (LPS group), the annulus fibrosis cells showed a significant decrease in inflammation-related genes, cell anabolism and catabolism-related genes. The DCs / PDA / GelMA group showed different degrees of reduction in intracellular inflammation gene levels, while the DCs / PDA / GelMA+NIR group showed the most obvious anti-inflammatory effect. Figure 7A The DCs / PDA / GelMA+NIR group showed the highest expression of heat shock protein-related genes. Figure 7B The DCs / PDA / GelMA+NIR group also showed the most obvious upregulation of extracellular matrix anabolism-related genes and downregulation of catabolism-related genes. Figure 7C Figure 7D The TIMP1 gene showed the highest expression in the DCs / PDA / GelMA+NIR group, indicating the most obvious inhibition of matrix degradation. The above shows that the combination of anti-inflammatory and hyperthermia has a stronger protective effect on cells.

[0084] Example 5 Mechanical property test of microneedle patch after freezing treatment or without treatment

[0085] This example relates to a method for preparing a freeze-strengthened hydrogel microneedle patch, which specifically comprises: first preparing PDA / GelMA hydrogel microneedle patches and GelMA hydrogel microneedle patches according to the preparation method of Example 2. Then, the prepared hydrogel microneedle patch is placed in a-20℃ refrigerator for 4h, then placed in a-80℃ refrigerator for 4h, and finally placed in liquid nitrogen for 1h to obtain a freeze-strengthened hydrogel microneedle patch.

[0086] Mechanical property test experiment: The mechanical properties of the hydrogel microneedle patch were tested on a universal material testing machine. The hydrogel-based microneedle patch was placed horizontally on the base of the machine, with the tip pointing vertically upward. The mechanical sensor was vertically downward, slowly approaching the microneedle patch. When the needle tip was just touched, the sensor moved downward at a speed of 0.5mm / min for 60s, and the process was repeated. Then, the data was recorded and the compression modulus and mechanical strength were calculated. The mechanical test of the freeze microneedle patch is consistent with the above steps, except that the frozen environment needs to be maintained.

[0087] ​The results of the mechanical testing experiment show that there is no statistical difference in the compression modulus and mechanical strength of the GelMA hydrogel microneedle patch and the PDA / GelMA hydrogel microneedle patch, while the compression modulus and mechanical strength of the cryo-PDA / GelMA hydrogel microneedle patch after freezing treatment are significantly improved, and it is observed that the cryo-PDA / GelMA microneedle patch successfully penetrates into the intervertebral disc tissue Figure 8

[0088] It should be understood that the above specific embodiments of the present application are only used for illustrative or explanatory purposes of the principles of the present application, and do not constitute a limitation on the present application. Therefore, any modification, equivalent replacement, improvement, etc. made without departing from the spirit and scope of the present application shall be included in the protection scope of the present application. In addition, the appended claims of the present application are intended to cover all variations and modifications falling within the scope and boundary of the appended claims, or the equivalent forms of such scope and boundary.​

Claims

1. A method for preparing a hydrogel microneedle patch with combined anti-inflammatory and thermotherapy effects, characterized in that, Polydopamine nanoparticles loaded with the drug diclofenac sodium were mixed with a biocompatible material solution containing a photoinitiator to obtain a pregel solution. The pregel solution was then dropped onto a mold, dried, and crosslinked under blue light to obtain a hydrogel microneedle patch.

2. The preparation method according to claim 1, characterized in that, The hydrogel microneedle patch is also subjected to cryogenic enhancement treatment, specifically: the hydrogel microneedle patch is first placed in a -20℃ refrigerator for 3-4 hours, then placed in a -80℃ refrigerator for 3-4 hours, and finally placed in liquid nitrogen for 1-2 hours.

3. The preparation method according to claim 1, characterized in that, A method for preparing drug-loaded polydopamine nanoparticles includes the following steps: (1) After mixing polyether and mesitylene, add it to a mixture of water and anhydrous ethanol. Stir for 20-30 min, then add dopamine hydrochloride Tris solution and continue stirring for 24-36 h. After washing, polydopamine nanoparticles are obtained. (2) Add polydopamine nanoparticles to the drug solution, stir for 12-24 h, and then wash to obtain drug-loaded polydopamine nanoparticles.

4. The preparation method according to claim 3, characterized in that, In step (1), the mass-to-volume ratio of polyether and mesitylene is (0.2-0.36) g: (0.2-0.36) mL.

5. The preparation method according to claim 1, characterized in that, The photoinitiator is lithium phenyl-2,4,6-trimethylbenzoylphosphonate; the biocompatible material is methacrylamide gelatin.

6. The preparation method according to claim 1, characterized in that, The specific process for preparing hydrogel microneedle patches from pregel solution is as follows: the pregel solution is dropped into the mold, vacuum is performed to remove air from the needle tip, and the temperature is maintained at 35-40℃; after the device is degassed, the temperature is kept constant, and the air bubbles on the surface of the solution are quickly removed. The above operation is repeated 3-5 times; then it is dried, crosslinked with blue light for 3-5 minutes, and finally demolded.

7. A hydrogel microneedle patch with combined anti-inflammatory and thermotherapeutic effects, characterized in that, The hydrogel microneedle patch, prepared by any one of claims 1-6, comprises a substrate and a plurality of microneedles disposed on the top of the substrate.

8. The use of the hydrogel microneedle patch with combined anti-inflammatory and thermotherapy effects as described in claim 7 in the preparation of products for treating intervertebral disc degeneration.

9. The application according to claim 8, characterized in that, The hydrogel microneedle patch, which combines anti-inflammatory and thermotherapy effects, promotes rapid drug delivery through external stimulation, regulates drug release, and promotes tissue repair through thermotherapy.

Images