Preparation method and application of porous GelMA microneedle for delivering AIE molecules based on HSF derived exosome

Abstract

The invention discloses a preparation method and application of a porous GelMA microneedle for delivering AIE molecules based on HSF derived exosome. The preparation method comprises the following steps: S1, preparing TTMN molecules; s2, dispersing DPPC and Chol in chloroform, performing water bath evaporation at 50 DEG C to form a thin film, hydrating the thin film in PBS, incubating to enable DPPC and Chol to form a liposome structure again, and uniformly dispersing TTMN molecules in the liposome structure to obtain TL; s3, extracting an exosome from the HSF cells; s4, loading the TL into the exosome by utilizing an electroporation technology, so as to obtain TE; s5, preparing the GelMA; and S6, mixing the GelMA with the TE, so that the TE is uniformly dispersed in the GelMA to obtain a mixed solution, injecting the mixed solution into a microneedle mold, and irradiating with 405nm laser to obtain the porous GelMA microneedle. According to the invention, high-efficiency treatment of hypertrophic scars is realized, and the system has a remarkable drug delivery effect, an innovative photodynamic therapy, a high-efficiency scar tissue remodeling effect and good biological safety and stability, and has important clinical application value and market prospect.

Description

Technical Field

[0001] The present invention belongs to the field of biomedicine technology, and in particular relates to a preparation method and application of a porous GelMA microneedle based on HSF-derived exosomes for delivering AIE molecules. Background Art

[0002] Hypertrophic scar (HS) is a pathological scar formed due to excessive healing after skin trauma or surgery, which is characterized by excessive proliferation of fibroblasts and excessive deposition of extracellular matrix (ECM), especially abnormal deposition of collagen fibers. This abnormal healing process causes scar tissue to bulge and thicken, and is often accompanied by uncomfortable symptoms such as itching and pain, which not only affects the patient's appearance but may also cause functional impairment. Therefore, how to effectively prevent and treat hypertrophic scars has always been a hot topic and difficulty in the clinical and scientific research fields.

[0003] At present, there are many methods for treating hypertrophic scars, including pressure therapy, silicone dressings, steroid injections, surgical excision, radiotherapy, and laser therapy. Although these methods can alleviate the symptoms of scars to a certain extent, there are many problems. Pressure therapy and silicone dressings have long treatment cycles and poor patient compliance; although steroid injections can inhibit scar hyperplasia, long-term use may lead to hormone dependence and side effects; surgical excision has a high risk and may recur; radiotherapy and laser therapy are expensive and may cause other side effects. Therefore, it is urgent to develop an efficient and low-side effect treatment method to solve this clinical problem.

[0004] In recent years, photodynamic therapy (PDT) has gradually attracted attention due to its advantages such as high selectivity, low trauma, and fast recovery. PDT uses photosensitizers (PSs) to generate reactive oxygen species (ROS) under the irradiation of light of a specific wavelength, thereby killing diseased tissues or cells. However, traditional PSs have an aggregation-caused quenching (ACQ) effect in their applications, that is, PSs will aggregate at high concentrations, resulting in a significant decrease in fluorescence and ROS generation efficiency, affecting the therapeutic effect. In addition, the limited diffusion distance of ROS in biological tissues also limits the application of PDT. Therefore, how to improve the ROS generation efficiency of PSs and achieve its efficient delivery has become an urgent problem to be solved in the current PDT field.

[0005] In addition, aggregation-induced emission (AIE) molecules have attracted much attention because they can significantly enhance fluorescence and ROS generation in the aggregated state. AIE molecules can overcome the ACQ effect of traditional PSs and have higher photostability and ROS generation ability. However, how to efficiently deliver AIE molecules to target tissues and achieve their effective function in vivo remains a challenge.

[0006] Exosomes, as an important carrier of intercellular information transmission, have natural biocompatibility and low immunogenicity, and can carry a variety of bioactive molecules, making them an ideal drug delivery system. The delivery efficiency and therapeutic effect of AIE molecules to the hypertrophic scar site through exosomes can be further improved by combining microneedle technology. As a minimally invasive drug delivery system, microneedle patches can penetrate the stratum corneum of the skin and deliver drugs directly to the subcutaneous tissue, with the advantages of precise drug delivery and high patient compliance. Summary of the invention

[0007] The purpose of the present invention is to provide a preparation method and application of porous GelMA microneedles based on HSF-derived exosomes delivering AIE molecules for the treatment of hypertrophic scars, aiming to overcome the shortcomings of the prior art and improve the treatment effect.

[0008] In order to achieve the above purpose, this application adopts the following technical solutions:

[0009] In a first aspect, the present invention provides a method for preparing a porous GelMA microneedle based on HSF-derived exosomes for delivering AIE molecules, the preparation method comprising the following steps:

[0010] S1, preparation of TTMN molecule, the structural formula of the TTMN molecule is:

[0011]

[0012] S2, preparation of TL: DPPC and Chol are dispersed in chloroform, evaporated in a water bath to form a thin film, the thin film is hydrated in PBS and then incubated to allow the DPPC and Chol to re-form a liposome structure, and the TTMN molecules are uniformly dispersed therein to obtain TTMN liposomes, namely TL;

[0013] S3, extraction of exosomes from HSF cells;

[0014] S4, preparation of TE: loading the TL into the exosomes using electroporation technology to obtain TE;

[0015] S5, preparation of GelMA;

[0016] S6, preparation of porous GelMA microneedles: mixing the GelMA with TE to uniformly disperse TE in the GelMA to obtain a mixed solution, injecting the mixed solution into a microneedle mold, and irradiating with laser to form a microneedle array with a porous structure, thereby obtaining the porous GelMA microneedles.

[0017] In the above technical solution, in S4, after the TL is loaded into the exosomes by electroporation technology, the excess TTMN is removed by ultrasound and centrifugation technology.

[0018] In the above technical scheme, in S5, the specific preparation method of GelMA is: by physical mixing method, methacrylic anhydride gelatin is mixed with polyethylene oxide and 2,4,6-trimethylbenzoyl in a ratio of 100:10-20:3-10.

[0019] In a second aspect, the present invention provides a porous GelMA microneedle patch based on HSF-derived exosomes for delivering AIE molecules, and the preparation method of the porous GelMA microneedle patch is:

[0020] The porous GelMA microneedle is prepared by the above preparation method;

[0021] The porous GelMA microneedle patch is obtained by filling the base portion of the porous GelMA microneedle with a GelMA solution and curing the base portion by laser irradiation.

[0022] In a third aspect, the present invention provides the use of the porous GelMA microneedle patch in the preparation of a medical product for treating hypertrophic scars.

[0023] In the above technical solution, the porous GelMA microneedle patch is applied to the target scar area, and a white light laser device is used to irradiate the patch area.

[0024] The beneficial effects of the present invention are: the present invention significantly improves the photodynamic efficacy of AIE molecules through an innovative drug delivery system and microneedle technology, has the advantages of high efficiency, low side effects, and simple operation, significantly improves the therapeutic effect of hypertrophic scars, and improves the quality of life of patients. The present invention achieves efficient treatment of hypertrophic scars by constructing a porous GelMA microneedle patch based on HSF-derived exosomes to deliver AIE molecules, which has significant advantages and innovations compared to the prior art.

[0025] (1) Efficient drug delivery system: Traditional scar treatment methods such as surgical excision, laser therapy and drug injection have problems such as unstable treatment effect, large trauma, long recovery time and many side effects. The present invention uses HSF-derived exosomes to deliver AIE molecules and achieves efficient drug delivery in the form of GelMA microneedle patches. Exosomes have natural biocompatibility and targeting, can effectively carry and protect drugs, avoid premature degradation and clearance of drugs in the body, and improve drug utilization and therapeutic effects. At the same time, GelMA microneedles can penetrate the skin barrier and deliver drugs directly to scar tissue, greatly improving the local concentration and therapeutic effect of drugs.

[0026] (2) Innovative photodynamic therapy (PDT) The present invention combines AIE molecules with photodynamic therapy, and utilizes the highly efficient reactive oxygen species (ROS) generated by AIE molecules under light to induce apoptosis of HSF cells in scar tissue and inhibit their proliferation and migration. AIE molecules have excellent photostability and biocompatibility, and can produce significant therapeutic effects at low doses, avoiding the phototoxicity and side effects of traditional photosensitizers. At the same time, photodynamic therapy has the advantages of non-invasiveness, precise positioning, and simple operation. It can achieve precise treatment of scar tissue, reduce damage to surrounding normal tissues, and improve the safety and effectiveness of treatment.

[0027] (3) Efficient scar tissue remodeling effect: The GelMA microneedle patch of the present invention can not only deliver drugs, but also has good mechanical strength and biocompatibility, and can effectively support and promote the remodeling of scar tissue. Through the puncture of the microneedle, it can promote local blood circulation and metabolism, and accelerate the repair and regeneration of scar tissue. At the same time, the GelMA material has good degradability and biocompatibility, can gradually degrade in the body, will not cause inflammatory reactions and foreign body rejection, and improves the safety of treatment and patient compliance.

[0028] (4) Significant scar treatment effect: Through animal experiments and cell experiments, the GelMA microneedle patch of the present invention showed significant effects in the treatment of hypertrophic scars. The results of animal experiments showed that after the application of the GelMA microneedle patch of the present invention, the thickness of the rabbit ear hypertrophic scar was significantly reduced, the tissue structure returned to normal, the inflammatory response was significantly alleviated, and the collagen fibers of the scar tissue were arranged more regularly, indicating that the present invention can effectively inhibit the proliferation and migration of scars and promote the repair and regeneration of scar tissue. The results of cell experiments showed that after the application of the GelMA microneedle patch of the present invention, the proliferation and migration of HSF cells were significantly inhibited, and the cell apoptosis rate was significantly increased, indicating that the present invention can effectively inhibit the activity of fibroblasts in scar tissue and improve the microenvironment of scar tissue, thereby achieving the purpose of treating hypertrophic scars.

[0029] (5) Biosafety and stability: The GelMA microneedle patch of the present invention adopts materials and preparation processes with good biocompatibility, and has high biosafety and stability. Through a series of biosafety tests, the results show that the GelMA microneedle patch of the present invention does not cause obvious inflammatory reactions and toxic side effects, and has high clinical application potential. At the same time, the preparation process of the present invention is simple and easy, and can be mass-produced and applied, and has good market prospects and application value.

[0030] (6) Innovation and practicality: The present invention proposes a new treatment scheme for hypertrophic scars by combining exosome technology, AIE molecules and GelMA microneedle technology, which has significant innovation and practicality. Exosome technology can achieve efficient drug delivery and targeted therapy, AIE molecules have excellent photodynamic therapy, and GelMA microneedles have good mechanical strength and biocompatibility. The combination of the three can significantly improve the effect and safety of scar treatment. The GelMA microneedle patch of the present invention has a wide range of application prospects. It is not only suitable for the treatment of hypertrophic scars, but can also be extended to other skin diseases and tissue repair fields. It has important clinical application value and market prospects.

[0031] In summary, the present invention achieves efficient treatment of hypertrophic scars by constructing a porous GelMA microneedle patch based on HSF-derived exosomes to deliver AIE molecules. It has significant drug delivery effect, innovative photodynamic therapy, efficient scar tissue remodeling effect, and good biosafety and stability, and has important clinical application value and market prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 : Characterization diagram. (A) TEM images of TL and (B) TE. (C) Zeta potential of lip@exo, TL and TE. (D) UV-visible absorption of TE and TTMN. (E) Size distribution of lip@exo, (F) TL and (G) TE. (H) Monitoring of size distribution over time.

[0033] Figure 2 : In vitro permeation. (A) Schematic diagram of the Transwell model. (B) Confocal images of the bottom chamber of the Transwell model treated with TL and TE.

[0034] Figure 3: In vitro treatment effects. (A) Cell viability after HSF co-incubation with different concentrations of TL or TE. (B) Quantification of ROS-positive cells. (C) Cell viability of different treatment groups. (D) Representative immunofluorescence staining images of ROS. Flow cytometry analysis of cell apoptosis. (E) Statistical analysis and (H) representative apoptosis detection. (F) Expression of apoptosis-related proteins and (G) corresponding quantitative analysis.

[0035] Figure 4 : Synthesis and characterization of microneedle patches. (A) Schematic diagram of the microneedle patch fabrication process. (B) SEM images and magnified images of conventional GelMA and (C) porous GelMA. (D) Drug release profiles of conventional GelMA and porous GelMA. (E) SEM images of the side and (F) top view of the fabricated MNs. (G) Optical image of TE MNs. (H) Storage modulus and loss modulus of porous GelMA.

[0036] Figure 5 : Application of GelMA microneedles in rabbit ear model. (A) Treatment flow chart. (B) Scar changes on days 21, 28, 35, and 42. (C) Quantification of scar elevation index (SEI). (D) and (E) Quantification and representative immunofluorescence staining of TUNEL. (F) HE staining of HS. (G) Collagen type I analysis using WB.

[0037] Figure 6 .Ultrasound imaging after treatment. DETAILED DESCRIPTION

[0038] In order to better illustrate the purpose, technical solutions and advantages of the present invention, the present invention will be further described below in conjunction with specific embodiments. The present invention can be implemented in many different forms and should not be construed as being limited to the embodiments set forth herein. On the contrary, these embodiments are provided so that this disclosure will be thorough and complete, and the concept of the present invention will be fully conveyed to those skilled in the art, and the present invention will only be limited by the claims.

[0039] The present invention relates to a preparation method and application of porous GelMA microneedles based on HSF-derived exosomes delivering AIE molecules for the treatment of hypertrophic scars. The invention integrates photodynamic therapy (PDT), aggregation-induced emission (AIE) molecules, exosome delivery system and microneedle technology, significantly improving the scar treatment effect.

[0040] The preparation method of the porous GelMA microneedle patch of the present invention is as follows:

[0041] 1. Preparation and functionalization of AIE molecules

[0042] The TPECM-2BA molecule (TTMN) with aggregation-induced emission properties was synthesized and purified, and chemical methods were used to make it have good photosensitivity and biocompatibility. The structural formula of TTMN is as follows:

[0043]

[0044] As one example, the specific preparation method of TTMN is as follows: a brominated aryl compound and thiophene nitrile boronic acid are reacted in an ethanol solution at 78° C. for 12 hours in the presence of a palladium catalyst (Pd(OAc)2) and potassium carbonate (K2PO4) as a base to generate an intermediate product. Subsequently, the reaction system is transferred to an acetonitrile solvent and the reaction is continued at 78° C. for 3 days to obtain the target product.

[0045] 2. Preparation of TL and TE

[0046] DPPC and cholesterol (Chol) were dispersed in chloroform and evaporated at 50°C to form a film. After the film was hydrated, TTMN molecules were evenly dispersed in it to obtain TTMN-containing liposomes (TL). TL was then loaded into HSF-derived exosomes using electroporation technology to form TE. Excess TTMN was removed by ultrasound and centrifugation technology, and TE was finally collected.

[0047] As one embodiment, the specific method for extracting exosomes from HSF cells is: separating exosomes by differential centrifugation. First, the HSF cell culture supernatant is centrifuged at low speed to remove cells and cell debris, and then the exosomes are collected by ultracentrifugation (above 100,000 g).

[0048] 3. Preparation of GelMA microneedle patch

[0049] 6% (w / v) methacryloyl gelatin (GelMA) was mixed with TE solution and placed in a mold. A 405nm laser was used to initiate a cross-linking reaction to form a porous GelMA microneedle patch. The base of the patch was filled with GelMA and irradiated again, and the microneedle patch was finally peeled off and stored in a dark place.

[0050] As one embodiment, the preparation method is as follows:

[0051] 1. Preparation and application of TTMN liposomes

[0052] (1) Material preparation

[0053] 12-Dipalmitoyl-sn-glycero-3-phosphorylcholine (DPPC) was purchased from Avanti Polar Lipids; cholesterol (Chol) was also purchased from Avanti Polar Lipids; chloroform was purchased from Thermo Fisher Scientific; and TTMN molecules were active molecules synthesized in the laboratory.

[0054] (2) Preparation of TTMN liposomes

[0055] The steps for preparing TTMN liposomes are as follows: First, accurately weigh 27 mg DPPC and 3 mg cholesterol and dissolve them in an appropriate amount of chloroform to form a uniform mixed solution. Subsequently, the solution is evaporated in a 50°C water bath to remove the chloroform solvent and form a uniform film. Next, the film is hydrated in PBS (phosphate buffered saline) and incubated at 37°C for 5 minutes to allow DPPC and Chol to re-form the liposome structure, while 3 mg TTMN molecules are uniformly dispersed therein, and finally TTMN liposomes (TL) are obtained.

[0056] (3) Characteristic analysis of TTMN liposomes

[0057] To ensure that the physical properties of TL meet the experimental requirements, a series of analyses were performed, such as Figure 1 As shown. First, the particle size of TL was measured using dynamic light scattering (DLS) technology, and the results showed that its average particle size was 120nm, indicating that the prepared TL had a suitable size, which was conducive to subsequent cell experimental applications. In addition, the morphology of TL was observed by transmission electron microscopy (TEM), and the image showed that TL had a uniform spherical structure, further confirming the stability and repeatability of the preparation process.

[0058] (4) Application of TTMN liposomes

[0059] After completing the preparation and characterization of TL, we further studied its potential for biomedical applications. First, we tested the penetration of TTMN molecules delivered by HSF exosomes. Figure 2 TL or TE was co-cultured with HSF cells in the Transwell chamber, and then the medium was changed to remove TL and TE, and the treated HSF cells were co-cultured with the bottom cells. It can be seen that the cells treated with TL and TE showed red fluorescence, and the fluorescence intensity in the TE group was stronger, indicating that TE has better cell penetration depth and cell phagocytosis effect.

[0060] like Figure 3The results show the in vitro therapeutic effect. The PBS group was the control group, which was treated with only an equal amount of PBS, the L group was the light-only group, the TE group was the TE-only group, the TL+L group was the light-after-TL group, and the TE+L group was the light-after-TE group. TL was applied to the culture system of human hypertrophic scar fibroblasts (HSF) to evaluate its effect on cell proliferation and migration. Cell activity was measured by cell counting kit-8 (CCK-8), and cell migration ability was observed using a cell scratch assay. The results showed that TL could significantly inhibit the proliferation and migration of HSF cells. This result suggests that TTMN liposomes may be used as an effective drug carrier for the treatment of hypertrophic scars and have important clinical application prospects.

[0061] (5) Results analysis

[0062] Through the above experiments, we not only successfully prepared TTMN liposomes, but also preliminarily verified its potential in inhibiting HSF cell proliferation and migration. The preparation process of TL is simple, low-cost, and has good biocompatibility and stability, which provides a solid foundation for further drug development and clinical application.

[0063] 2. Preparation and application of TE-loaded porous GelMA microneedle patches

[0064] (1) Material preparation

[0065] GelMA (gelatin modified with methacrylate), exosomes extracted from HSF (hypertrophic scar fibroblasts) cells, and TE (TTMN-loaded exosomes) prepared by electroporation. All materials were carefully selected and prepared to ensure the biocompatibility and effectiveness of the microneedle patch.

[0066] The specific preparation method of GelMA is as follows: by physical mixing method, methacrylic anhydride gelatin is mixed with polyethylene oxide and 2,4,6-trimethylbenzoyl in a ratio of 100:10-20:3-10 to obtain GelMA.

[0067] The specific method for extracting exosomes from HSF cells is as follows: exosomes are separated by differential centrifugation steps. First, the HSF cell culture supernatant is centrifuged at low speed to remove cells and cell debris, and then the exosomes are collected by ultracentrifugation (above 100,000 g).

[0068] (2) Preparation of porous GelMA microneedles

[0069] First, a 6% (w / v) GelMA solution was accurately prepared and mixed evenly with 50 μL TE solution at 37°C to ensure that TE was evenly dispersed in the GelMA solution. Subsequently, the mixed solution was injected into the microneedle mold and irradiated with a 405nm laser to induce the cross-linking reaction of GelMA to form a microneedle array with a porous structure. The porous structure is conducive to improving the drug loading and release efficiency.

[0070] (3) Preparation of microneedle patches

[0071] After forming the microneedle array, the GelMA solution is used to fill the base part of the microneedle and solidified by laser irradiation. This step ensures the firm bonding of the microneedle to the base, forming a complete TE-loaded porous GelMA microneedle patch. The preparation process of the patch must be carried out under sterile conditions to ensure the safety and stability of the product. Figure 4 Shown is the synthesis and characterization of the microneedle patch.

[0072] (4) Application of microneedle patches:

[0073] This study used New Zealand rabbits as an animal model to create hypertrophic scars in their ears to simulate scar hyperplasia in humans. The prepared TE-loaded porous GelMA microneedle patch was applied to the hypertrophic scar model of the rabbit ear, and the therapeutic effect of the microneedle patch was evaluated by observing and analyzing the scar thickness, tissue structure, and inflammatory response.

[0074] like Figure 5 The figure shows the application of GelMA microneedles on the rabbit ear model, where the Control group is the control group, the L group is the light-only group, the TE group is the TE-only group, the TL+L group is the light-after-TL group, and the TE+L group is the light-after-TE group. The experimental results show that the TE-loaded porous GelMA microneedle patch can effectively penetrate the surface of the skin and deliver TE deep into the scar tissue. In the scar tissue, TE releases TTMN and produces reactive oxygen species (ROS) through photodynamic action, which effectively inhibits the proliferation and migration of HSF cells and promotes cell apoptosis, thereby significantly reducing the thickness of the scar. In addition, through histological examination (such as HE staining) and immunofluorescence staining (such as TUNEL staining), it was found that the tissue structure of the microneedle patch treatment area was significantly improved, and the infiltration of inflammatory cells was reduced, indicating that the microneedle patch has good anti-inflammatory and tissue repair effects.

[0075] (5) Result analysis:

[0076] The above animal models have verified the therapeutic potential of microneedle patches for hypertrophic scars. The preparation process of microneedle patches is simple and controllable, and they have good biocompatibility and degradability, providing a new strategy for scar treatment. In the future, we will further explore the application of this microneedle patch in the treatment of different types of scars and evaluate its long-term safety and effectiveness.

[0077] 3. Synergistic treatment mechanism of photodynamic therapy and microneedle patch

[0078] The TE-loaded porous GelMA microneedle patch was applied to the hypertrophic scar site, and the microneedles penetrated the skin to efficiently deliver the AIE molecules to the scar tissue. Under white light laser irradiation, the AIE molecules produced efficient ROS, induced apoptosis of HSF cells in scar tissue, inhibited their proliferation and migration, and promoted collagen remodeling.

[0079] (1) Material preparation:

[0080] A white light laser device, used to provide the necessary light energy, purchased from Thermo Fisher Scientific; and the above successfully prepared TE-loaded porous GelMA microneedle patch, used as a drug carrier and therapeutic tool.

[0081] (2) Implementation of photodynamic therapy:

[0082] When treating hypertrophic scars, the TE-loaded porous GelMA microneedle patch is first carefully applied to the target scar area. Through moderate pressure and the mechanical action of the microneedle, it is ensured that the microneedle can completely penetrate the epidermis of the skin, allowing the drug to act directly on the scar tissue. Subsequently, a white light laser device is used to irradiate the patch area. Each irradiation lasts for 10 minutes to ensure that enough light energy is absorbed by the TTMN in the TE to trigger a photodynamic reaction. The treatment is performed 3 times a week for 4 consecutive weeks to achieve the best therapeutic effect.

[0083] (3) Evaluation of the effect of photodynamic therapy:

[0084] To evaluate the therapeutic effect of photodynamic therapy on hypertrophic scars, a series of biomedical analysis methods were used. Histological staining, such as HE staining, was used to observe the changes in scar tissue structure and evaluate the infiltration of inflammatory cells and the degree of tissue repair. Immunofluorescence staining, such as TUNEL staining, was used to detect the apoptosis of HSF cells. In addition, the expression of proteins related to apoptosis and collagen synthesis, such as Bax, Bcl-2, and Caspase-3, as well as the level of collagen I were analyzed by Western blotting.

[0085] like Figure 5The figure shows the application of GelMA microneedle on the rabbit ear model. A hole was made on the left ear of the rabbit through surgery to create a model. The rabbits were treated in groups on the 20th day after the hole was made, and the scar condition was continuously observed until the 42nd day, when the rabbits were killed and the rabbit ear tissues were collected for analysis. The experimental results showed that in the scar tissue treated with photodynamic therapy, the apoptosis of HSF cells increased significantly, and the proliferation and migration of cells were significantly inhibited. At the same time, the remodeling of collagen was promoted, and the repair process of scar tissue was accelerated. By measuring the scar height and observing the appearance of the scar, it was found that the TE-loaded porous GelMA microneedle patch combined with photodynamic therapy can effectively reduce the height and redness of the scar and improve the aesthetics of the scar.

[0086] (4) Ultrasound imaging:

[0087] Ultrasonic imaging was performed to observe the ultrasound images of rabbit ear scars. Figure 6 The ultrasound images after treatment are shown. The scars on the rabbit ears in the TE+L group have basically disappeared.

[0088] (5) Safety assessment:

[0089] During the treatment, the treated rabbits were monitored in detail, including observation of local skin and recording of systemic reactions. No obvious side effects such as allergic reactions, pain or infection were observed during the treatment. In addition, the systemic safety of the treatment was evaluated by routine blood and liver function tests, and the results showed that the treatment did not have a negative impact on the rabbits' systemic health.

[0090] (6) Result analysis:

[0091] Studies have shown that TE-loaded porous GelMA microneedle patches combined with photodynamic therapy are a safe and effective treatment strategy for hypertrophic scars. Through local drug delivery and photodynamic action of microneedles, precise inhibition of HSF cells is achieved, promoting the repair and remodeling of scar tissue. This method not only improves the treatment effect, but also reduces the side effects that may be caused by traditional photodynamic therapy, providing a new option for the treatment of hypertrophic scars.

[0092] Obviously, the above embodiments are merely examples for the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived therefrom are still within the scope of protection of the invention.

Claims

1. A method for preparing porous GelMA microneedles based on HSF-derived exosomes delivering AIE molecules, characterized by: The preparation method comprises the following steps: S1, preparation of TTMN molecule, the structural formula of the TTMN molecule is: S2, preparation of TL: DPPC and Chol are dispersed in chloroform, evaporated in a water bath to form a thin film, the thin film is hydrated in PBS and then incubated to allow the DPPC and Chol to re-form a liposome structure, and the TTMN molecules are uniformly dispersed therein to obtain TTMN liposomes, namely TL; S3, extraction of exosomes from HSF cells; S4, preparation of TE: loading the TL into the exosomes using electroporation technology to obtain TE; S5, preparation of GelMA; S6, preparation of porous GelMA microneedles: mixing the GelMA with TE to uniformly disperse TE in the GelMA to obtain a mixed solution, injecting the mixed solution into a microneedle mold, and irradiating with laser to form a microneedle array with a porous structure, thereby obtaining the porous GelMA microneedles.

2. The preparation method according to claim 1, characterized in that: In S4, the TL is loaded into the exosomes by electroporation technology, and then the excess TTMN is removed by ultrasound and centrifugation technology.

3. The preparation method according to claim 1, characterized in that: In S5, the specific preparation method of the GelMA is: by physical mixing method, methacrylic anhydride gelatin, polyethylene oxide and 2,4,6-trimethylbenzoyl are mixed in a mass ratio of 100:10 to 20:3 to 10 to obtain.

4. A porous GelMA microneedle patch based on HSF-derived exosomes delivering AIE molecules, characterized by: The preparation method of the porous GelMA microneedle patch is: The porous GelMA microneedle is prepared by the preparation method according to any one of claims 1 to 3; The porous GelMA microneedle patch is obtained by filling the base portion of the porous GelMA microneedle with a GelMA solution and curing the base portion by laser irradiation.

5. Use of the porous GelMA microneedle patch according to claim 4 in preparing a medical product for treating hypertrophic scars.

6. The application according to claim 5, characterized in that: The porous GelMA microneedle patch is applied to the target scar area, and a white light laser device is used to irradiate the patch area.

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