Alpha-lipoic acid liposome photo-thermal response type hydrogel coating capable of inhibiting scars and promoting wound healing as well as preparation method and application of alpha-lipoic acid liposome photo-thermal response type hydrogel coating

Abstract

The invention provides an alpha-lipoic acid liposome photo-thermal response type hydrogel coating capable of inhibiting scars and promoting wound healing as well as a preparation method and application of the alpha-lipoic acid liposome photo-thermal response type hydrogel coating. The preparation method of the hydrogel coating comprises the following steps: carrying out plasma treatment on a substrate, soaking the substrate in a KH570 solution, then soaking the substrate in a TPO-L ethyl acetate solution, finally soaking the substrate in a hydrogel precursor solution, and carrying out a reaction to obtain the hydrogel coating. The hydrogel coating has the effects of inhibiting scars and promoting tissue regeneration and wound healing, the wound healing speed can be increased, and the experience feeling of a patient is good. Besides, MXene is introduced into the hydrogel coating, so that the hydrogel coating has good photo-thermal responsiveness, and controllable release of the alpha-lipoic acid liposome is realized. The hydrogel coating disclosed by the invention not only has excellent oxidation resistance, but also has good lubricating property and mechanical durability, and has good biological drag reduction performance, so that the hydrogel coating has wide application prospects in the field of biomedicine.

Description

Technical Field

[0001] The present invention belongs to the fields of biomedicine and hydrogel, and specifically relates to an α-lipoic acid liposome photothermal responsive hydrogel coating capable of inhibiting scarring and promoting wound healing, as well as a preparation method and application thereof. Background Art

[0002] Hydrogel coatings that combine the functions of hydrogels and substrates have shown great potential in biomedical applications. At present, hydrogel coating technologies for inhibiting scar formation and promoting wound healing can effectively inhibit scar formation and promote wound healing through different mechanisms (such as anti-inflammatory, antioxidant, antibacterial, and angiogenesis-promoting). This type of hydrogel coating has a wide range of applications in the clinical treatment of chronic wounds and scar management. For example, Chinese patent document CN118949107A discloses an antibacterial dressing, preparation method, and application that promotes wound healing. In principle, the invention forms a gel copolymer network by gelatin and quaternary ammonium salts, and adds long-chain polyhydroxy alcohols thereto. The alcohol hydroxyl groups give the hydrogel the ability to adsorb water and oxygen, which can increase the oxygen concentration at the wound and promote the healing of damaged tissues. In addition, there are also reports of hydrogels that promote wound healing by using a dual method of electric current and electrically controlled drug release through electrically assisted means. For example, Chinese patent document CN119184963A discloses a hydrogel patch for electrically controlled drug release for wound healing. The surface of the hydrogel patch with the conductive hydrogel exposed and the sheet-shaped electrode with a central opening serves as the treatment surface facing the wound. This allows for long-term, continuous replenishment of the drug within the hydrogel and programmed drug release, synergistically promoting wound healing through electrical stimulation and drug release. The aforementioned patents primarily achieve wound healing through anti-inflammatory and antibacterial approaches, but these anti-inflammatory and antibacterial methods can result in a poor patient experience, slow wound healing rates, and potential impacts on human circulation caused by the current.

[0003] Inflammatory response is one of the important mechanisms of scar formation. Hydrogel coatings can effectively reduce the inflammatory response by regulating the release of inflammatory factors, thereby inhibiting the formation of scars. Recently, Liu et al. developed a tough, antibacterial and antioxidant hydrogel dressing that can accelerate wound healing and inhibit the formation of hypertrophic scars in infected wounds. This hydrogel dressing has excellent anti-inflammatory properties by combining a double network structure of polyvinyl alcohol (PVA) and agarose, which can significantly reduce the inflammatory response in infected wounds and thus inhibit scar hyperplasia (Liu X, Sun Y, Wang J, et al. A tough, antibacterial and antioxidant hydrogel dressing accelerates wound healing and suppresses hypertrophic scar formation in infected Wounds [J]. Bioactive Materials, 2024, 34: 269-281.). In addition to inflammatory response, oxidative stress is also an important mechanism of scar formation. Hydrogel coatings can inhibit scar formation by scavenging reactive oxygen species (ROS) and reducing the damage of oxidative stress to tissues. Recently, Zhang et al. constructed a biodegradable hydrogel loaded with verteporfin (VP-gel) that can continuously release antioxidants, effectively scavenge ROS, promote wound healing and reduce scar formation (Zhang C, Yang D, Wang TB, et al. Biodegradable hydrogels with photodynamic antibacterial activity promote wound healing and mitigate scarFormation[J]. Biomaterials Science, 2023, 11(1): 288-297.).

[0004] Furthermore, hydrogel coatings can effectively inhibit scar formation through multiple mechanisms, including antibacterial properties, angiogenesis promotion, and regulation of collagen synthesis and degradation. Their multifunctional synergistic effects provide an ideal environment for wound healing. Hydrogel coatings have shown great potential in clinical applications, particularly in the aforementioned wound healing and scar suppression aspects.

[0005] Reported scar-suppressing hydrogel coatings primarily rely on modulating inflammatory responses; structurally modifying the hydrogel coating to synthesize reducing molecules to enhance ROS scavenging capabilities; or using electrically assisted drug release. α-Lipoic acid, a potent antioxidant, has recently gained increasing attention in biomedical applications. To improve its bioavailability and stability, researchers have developed various nanocarrier systems, including liposomes and hydrogels, and have initially applied them to biological systems. For example, Chinese patent document CN115232329A discloses a lipoic acid hydrogel, its preparation method, and its applications. The resulting lipoic acid hydrogel exhibits efficient self-healing properties, is injectable, has high self-healing properties, and exhibits thermosensitivity, making it suitable for use in adhesives and dressings. The lipoic acid hydrogel obtained in this patent achieves wound healing through an antioxidant pathway, but does not address the issue of controlled release of lipoic acid. Chinese patent document CN115337446A discloses a method for preparing a bio-based adhesive hydrogel patch that promotes wound healing, as well as its product and applications. The preparation method of this hydrogel patch includes the following steps: mixing lipoic acid and cytosine nucleoside and reacting to obtain lipoic acid cytosine; mixing gelatin and methacrylic anhydride and reacting to obtain methacrylated gelatin GelMA; and heating the lipoic acid cytosine and GelMA, polymerizing to obtain a bio-based adhesive hydrogel patch. The hydrogel patch prepared by this invention combines the natural molecules lipoic acid and cytosine nucleoside with gelatin and can be effectively used to promote wound healing. However, the system does not contain any material components that can respond to external stimuli, resulting in the hydrogel patch being unable to release lipoic acid in response to light, heat, or other external stimuli. Furthermore, the biological drag reduction performance of the lipoic acid component in this invention needs to be further improved.

[0006] In summary, existing hydrogels that inhibit scarring and promote wound healing mainly achieve the expected wound healing through anti-inflammatory, antibacterial and antioxidant pathways; however, anti-inflammatory and antibacterial hydrogels mainly achieve the expected wound healing through anti-inflammatory and antibacterial pathways, but anti-inflammatory and bactericidal effects will result in a poor patient experience, a low wound healing rate, and electric current will potentially affect the human body's internal circulation; ordinary lipoic acid hydrogel coatings have the ability to scavenge ROS and can inhibit scar formation, but they cannot achieve controlled release and have poor biological drag reduction performance. Summary of the Invention

[0007] In response to the shortcomings of the existing technology in terms of patient experience, wound healing rate and controlled drug release, the present invention provides an α-lipoic acid liposome photothermal responsive hydrogel coating that can inhibit scarring and promote wound healing, as well as its preparation method and application. The preparation method and raw material composition of the α-lipoic acid liposome hydrogel coating of the present invention are simple, low-cost, scalable, environmentally friendly, easy to clean, and recyclable. The α-lipoic acid liposome hydrogel coating of the present invention uses the ROS scavenging properties of α-lipoic acid to inhibit scarring, promote tissue regeneration and wound healing, accelerate the rate of wound healing, and provide a good patient experience. In addition, due to the introduction of MXene into the α-lipoic acid liposome hydrogel coating, MXene has good photothermal responsiveness, thereby achieving controlled release of α-lipoic acid liposomes. The α-lipoic acid liposome hydrogel coating prepared by the present invention not only has excellent antioxidant properties, but also has good lubricity and mechanical durability, and has good biological drag reduction properties, giving it broad application prospects in the biomedical field.

[0008] The technical solutions of the present invention are as follows.

[0009] A method for preparing an α-lipoic acid liposome photothermal responsive hydrogel coating capable of inhibiting scarring and promoting wound healing comprises the following steps:

[0010] (1) Plasma-treating the substrate, then immersing it in a 3-(trimethylsilyl)propyl methacrylate (KH570) solution, and drying it to obtain a KH570-treated substrate;

[0011] (2) The KH570-treated substrate was immersed in an ethyl acetate solution of ethyl (2,4,6-trimethylbenzoyl) phenyl phosphate (TPO-L) and dried to obtain an initiator-treated substrate;

[0012] (3) immersing the substrate treated with the initiator in a hydrogel precursor solution to obtain an α-lipoic acid liposome photothermal responsive hydrogel coating that can inhibit scarring and promote wound healing;

[0013] The hydrogel precursor solution is a dispersion of methacrylated gelatin (GeLMA), polymethacrylate sulfobetaine (PSBMA), α-lipoic acid liposomes, Ti3AlC2 MAX and water.

[0014] Preferably according to the present invention, in step (1), the base material is selected from polyethylene terephthalate or high-density polyethylene.

[0015] According to the preferred embodiment of the present invention, in step (1), before the plasma treatment, the following steps are further included: ultrasonically cleaning the substrate to remove impurities on the surface, and drying in clean air.

[0016] According to the preferred embodiment of the present invention, in step (1), the conditions for plasma treatment are: pressure 5-20 Pa, power 5-20 W, and plasma treatment time 3-8 minutes, preferably 5 minutes.

[0017] According to a preferred embodiment of the present invention, in step (1), the solvent used for the 3-(trimethyloxysilyl)propyl methacrylate (KH570) solution is a mixture of ethanol and water, wherein the volume ratio of ethanol to water is 1-2:1; the content of 3-(trimethyloxysilyl)propyl methacrylate (KH570) in the 3-(trimethyloxysilyl)propyl methacrylate (KH570) solution is 1-5 wt %. The amount of 3-(trimethyloxysilyl)propyl methacrylate (KH570) solution used is sufficient to immerse the substrate.

[0018] According to the preferred embodiment of the present invention, in step (1), the soaking temperature is room temperature and the soaking time is 1-5 hours.

[0019] According to a preferred embodiment of the present invention, in step (2), the concentration of the ethyl (2,4,6-trimethylbenzoyl) phenyl phosphate (TPO-L) ethyl acetate solution is 1-5 wt %. The amount of the ethyl (2,4,6-trimethylbenzoyl) phenyl phosphate (TPO-L) ethyl acetate solution used is sufficient to immerse the substrate.

[0020] According to the preferred embodiment of the present invention, in step (2), the immersion temperature is room temperature and the immersion time is 20-40 seconds. After immersion, as the solvent evaporates, a stable initiator layer is formed on the surface of the substrate.

[0021] Preferably, according to the present invention, in step (3), the α-lipoic acid liposomes are composed of α-lipoic acid and a lipid membrane coated on the surface of the α-lipoic acid, and the lipid membrane is composed of soybean lecithin and cholesterol; the α-lipoic acid liposomes are added to the system in the form of an α-lipoic acid liposome suspension, wherein the solvent of the α-lipoic acid liposome suspension is a phosphate buffer solution with a pH of 7.4, and the concentration of the α-lipoic acid liposomes is 7-7.5 g / L.

[0022] According to the preferred embodiment of the present invention, in step (3), the preparation method of the α-lipoic acid liposome suspension is a thin film hydration method, comprising the steps of: dissolving soybean lecithin, cholesterol and α-lipoic acid in dichloromethane, removing dichloromethane by rotary evaporation to form a uniform thin lipid film; adding phosphate buffered saline (PBS) for hydration treatment; and then filtering to obtain the α-lipoic acid liposome suspension. Preferably, the mass ratio of soybean lecithin to cholesterol is 1-3:1, the mass ratio of the total mass of soybean lecithin and cholesterol to α-lipoic acid is 3-4:1; the volume ratio of the mass of α-lipoic acid to dichloromethane is 2-3g / L; the rotary evaporation temperature is 40°C; the pH of the phosphate buffer is 7.4, and the volume ratio of the mass of α-lipoic acid to the phosphate buffer is 1.5-2g / L; the hydration method is as follows: ultrasonic treatment at 35-45°C for 3-10min, then ultrasonic treatment at -5-5°C for 15-25min; the specification of the filter membrane is 0.45μm.

[0023] According to the present invention, in step (3), the mass ratio of methacrylated gelatin (GeLMA), polymethacrylate sulfobetaine (PSBMA), α-lipoic acid liposomes, and Ti3AlC2 MAX is 8-12:4-8:2-3:0.01-0.2, preferably 10:5:2-3:0.01-0.1, and further preferably 10:5:2.5:0.1.

[0024] According to the preferred embodiment of the present invention, in step (3), the mass ratio of Ti3AlC2MAX to water is 1-5 mg / mL.

[0025] According to a preferred embodiment of the present invention, in step (3), the reaction conditions are as follows: reaction under ultraviolet light for 20-50 seconds, then removal of the ultraviolet light and standing at room temperature for 5-50 seconds; the ultraviolet light irradiation power is 800-1200 W. Under ultraviolet light irradiation, free radicals generated by the oil-soluble TPO-L initiator promote the growth of the hydrogel coating from the substrate surface, thereby forming a uniform and stable α-lipoic acid liposome hydrogel coating.

[0026] An alpha-lipoic acid liposome photothermal responsive hydrogel coating capable of inhibiting scarring and promoting wound healing is prepared by the above method.

[0027] The application of the α-lipoic acid liposome photothermal responsive hydrogel coating capable of inhibiting scars and promoting wound healing in the preparation of drugs or dressings capable of inhibiting scars and promoting wound healing.

[0028] The technical features and beneficial effects of the present invention are as follows:

[0029] 1. The present invention uses plasma treatment on the substrate surface to activate the active hydroxyl groups on the substrate surface. The treated substrate is then immersed in a KH570 solution. The hydrolyzed silanol functional groups of the KH570 react with the active hydroxyl groups to form covalent siloxane bonds. After the siloxane bonds are formed, the treated substrate is immersed in an ethyl acetate solution of ethyl (2,4,6-trimethylbenzoyl) phenyl phosphate (TPO-L). As the solvent evaporates, a stable initiation layer gradually forms on the substrate surface. The substrate containing the initiation layer is then immersed in a hydrogel precursor solution and irradiated with an ultraviolet lamp. The oil-soluble TPO-L acts as an initiator to generate free radicals, which promote the graft polymerization of methacrylated gelatin (GeLMA) and polymethacrylate sulfobetaine (PSBMA) in the hydrogel precursor from the substrate surface (the covalent siloxane bonds formed by treating the substrate with KH570 can undergo graft polymerization with GelMA and PSBMA). The free radicals are further polymerized into a network structure. After polymerization, a uniform and stable α-lipoic acid liposome hydrogel coating is obtained, in which the α-lipoic acid liposomes and Ti3AlC2MAX are uniformly dispersed in the α-lipoic acid liposome hydrogel coating. The α-lipoic acid liposome hydrogel coating preparation method and raw material composition of the present invention are simple, low-cost, scalable, environmentally friendly, easy to clean, and recyclable.

[0030] 2. In the α-lipoic acid liposome hydrogel coating of the present invention, covalent bonds are formed between GelMA and PSBMA through free radical polymerization. α-lipoic acid liposomes and Ti3AlC2MAX are uniformly dispersed in the three-dimensional network hydrogel obtained by the polymerization of GelMA and PSBMA. In addition to the covalent bonds between GelMA and PSBMA, there are also electrostatic interactions and hydrogen bonds between the α-lipoic acid liposomes and the GelMA and PSBMA backbone structures, which enhance the interaction between the hydrogel components. GelMA and PSBMA polymerization together form the network backbone structure of the α-lipoic acid liposome hydrogel coating, which makes the hydrogel stable and can be prepared and molded. The incorporation of α-lipoic acid liposomes not only improves the lubricity of the coating, but also imparts antioxidant and antibacterial properties. The photothermal responsiveness of MXene enables the α-lipoic acid liposome hydrogel coating of the present invention to absorb light energy under NIR irradiation and convert it into heat energy, causing the α-lipoic acid liposomes to release α-lipoic acid, achieving controlled release.

[0031] 3. The α-lipoic acid liposome hydrogel coating of the present invention uses the ROS scavenging properties of α-lipoic acid to inhibit scarring, promote tissue regeneration and wound healing; through the NIR photothermal effect, α-lipoic acid molecules can be continuously and controllably released to clear excess ROS, reduce the level of reactive oxygen species around the wound, and reduce local tissue inflammation; α-lipoic acid can also promote the proliferation of endothelial cells and smooth muscle cells, while inhibiting the fibrosis process, promoting wound healing, promoting tissue regeneration and inhibiting scar formation. The present invention improves the stability, bioavailability and targeting of α-lipoic acid through the encapsulation of α-lipoic acid liposomes and hydrogels. α-lipoic acid liposomes and their hydrogels have shown potential applications in clinical treatment in multiple fields such as wound healing, anti-oxidation, antibacterial and skin care.

[0032] 4. The α-lipoic acid liposome hydrogel coating prepared by the present invention not only has excellent antioxidant properties, but also has good lubrication properties and mechanical durability, which makes it have broad application prospects in the biomedical field. The α-lipoic acid liposome hydrogel coating of the present invention has an ultra-low friction coefficient (0.001) and a high surface grafting density. The α-lipoic acid liposome hydrogel coating uses the hydrophobicity of the α-lipoic acid liposomes to improve the lubrication properties of the coating, resulting in the α-lipoic acid liposome hydrogel coating having an ultra-low friction coefficient and excellent biological drag reduction performance. Since the force between the α-lipoic acid liposome hydrogel coating and the substrate surface is a more firmly bonded covalent bond, the α-lipoic acid liposome hydrogel coating has excellent mechanical durability and can maintain structural integrity even after ultrasonic cleaning for 24 hours (400W) or 10,000 cycles of bending. The present invention uses a light-initiated method to prepare the α-lipoic acid liposome hydrogel coating, and the hydrogel precursor is grafted and polymerized on the surface of the substrate. The light-initiated graft polymerization and the presence of an initiation layer on the substrate surface increase the reaction sites on the substrate, so that the α-lipoic acid liposome hydrogel coating of the present invention has a high surface graft density.

[0033] 5. The α-lipoic acid liposome hydrogel coating prepared by the present invention has the performance of controlled release of α-lipoic acid. The mechanism is that MXene has good photothermal responsiveness, which can enable the α-lipoic acid liposome to achieve controlled release: when the α-lipoic acid liposome hydrogel coating is irradiated with NIR, due to the photothermal effect, MXene absorbs light energy and converts it into heat energy, thereby releasing α-lipoic acid and achieving controlled release.

[0034] 6. In the preparation method of the present invention, if plasma treatment is not performed, the active hydroxyl groups on the substrate surface cannot be activated and cannot undergo a condensation reaction with KH570 to form siloxane bonds. Similarly, if KH570 treatment is not performed, a condensation reaction to form siloxane bonds cannot occur. If PSBMA is not added, the hydrogel network skeleton structure is unstable and cannot be prepared and formed. In the hydrogel precursor solution, the raw materials methacrylated gelatin (GeLMA), polymethacrylate sulfobetaine (PSBMA), α-lipoic acid liposomes, and Ti3AlC2MAX need to be appropriately proportioned. If too much Ti3AlC2MAX is added, it will overheat under NIR irradiation; if α-lipoic acid liposomes are replaced with α-lipoic acid, the lubricity of the hydrogel coating will be reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 The graph shows the relationship between the storage modulus (G') and the loss modulus (G") of the hydrogel coatings obtained in Comparative Example 1 and Comparative Example 3.

[0036] Figure 2 Appearance of the α-lipoic acid liposome hydrogel coating (substrate is PET) prepared in Comparative Example 1 after 10,000 cycles of bending (the left picture is in a stretched state after 10,000 cycles of bending, and the right picture is in a contracted state after 10,000 cycles of bending).

[0037] Figure 3 These are appearance pictures of the α-lipoic acid liposome hydrogel coating (substrate is PET) prepared in Comparative Example 1 before and after 24 hours of ultrasonic cleaning (ultrasonic power is 400 W).

[0038] Figure 4 This is a comparative data graph of the water contact angle of the surface of the α-lipoic acid liposome hydrogel coating (substrate is PET) prepared in Comparative Example 1 after 10,000 cycles of bending and ultrasonic cleaning.

[0039] Figure 5 (a) is a test graph of the hemolytic ability of the hydrogel samples of Example 1, Comparative Example 2 and Comparative Example 3 on fresh rat red blood cells; (b) and (c) are schematic diagrams of the viability and proliferation ability of DF cells during the quantitative proliferation process obtained by the CCK-8 detection method for the hydrogel samples of Example 1, Comparative Example 2 and Comparative Example 3; (d) and (e) are test graphs of the ROS levels of DF cells of the hydrogel samples of Example 1, Comparative Example 2 and Comparative Example 3; (f) is a test graph of the expression levels of COL1A1 and MKi67 quantitatively measured by immunofluorescence staining of the hydrogel samples of Example 1, Comparative Example 2 and Comparative Example 3.

[0040] Figure 6(a) is a full-thickness excision model of a mouse wound in the hydrogel sample groups of Example 1, Comparative Example 2, and Comparative Example 3; (b) is an immunofluorescence staining image of MYHI1+ in the hydrogel sample groups of Example 1, Comparative Example 2, and Comparative Example 3 on the 5th and 10th day after injury; (c) is an immunofluorescence staining image of MKi67+ (proliferating cells) in the hydrogel sample groups of Example 1, Comparative Example 2, and Comparative Example 3 on the 5th and 10th day after injury; (d) is an immunofluorescence staining image of C in the hydrogel sample groups of Example 1, Comparative Example 2, and Comparative Example 3 Immunofluorescence staining images of NN1+ (smooth muscle cells) on the 5th and 10th days after injury; (e) is a graph showing the relationship between the changes in CD45+, CD31+ and MKi67+ cells and time in Example 1, Comparative Example 2 and Comparative Example 3; (f) is a comparison of the mRNA levels of fibrosis-related genes (Col1a1, Col3a1, Co3a1, Postn, Ctgf) and inflammatory factors (Mcp1, Tnfa, IL6) in Example 1, Comparative Example 2 and Comparative Example 3.

[0041] Figure 7 These are the adsorption patterns of Staphylococcus aureus on the surfaces of surgical sutures (blank sample), surgical sutures coated with a hydrogel coating (GelMA) prepared by the method of Comparative Example 4 without NIR irradiation, surgical sutures coated with an α-lipoic acid liposome hydrogel coating (Ge@PS-L-MX1) prepared by the method of Example 1 without NIR irradiation, and surgical sutures coated with an α-lipoic acid liposome hydrogel coating (NIR irradiated Ge@PS-L-MX1) prepared by the method of Example 1 under NIR irradiation.

[0042] Figure 8 (a) Schematic diagram of the friction test of hydrogel coating; Figure 8 (b) and Figure 8 (c) The friction coefficients of the hydrogel coatings prepared by the methods of Comparative Example 4 (GelMA), Comparative Example 3 (Ge@PS), and Comparative Example 1 (Ge@PS-L) under a constant normal force of 1 N and a constant rotation speed of 30 rad / min; Figure 8 (d) Graph showing the friction coefficient of the hydrogel coating prepared by Example 1 (Ge@PS-L-MX1) and Comparative Example 1 (Ge@PS-L) under a constant normal force of 1 N and a constant rotation speed of 30 rad / min.

[0043] Figure 9 (a) Temperature variation diagram of hydrogel coatings with different MXene contents under NIR irradiation (0.839 W); Figure 9 (b) Infrared thermal imaging of the hydrogel coatings prepared by the methods of Comparative Example 1 (Ge@PS-L-MX0) and Example 1 (Ge@PS-L-MX1) under NIR irradiation (0.839 W). DETAILED DESCRIPTION

[0044] The present invention will be further described below with reference to specific examples, but is not limited thereto.

[0045] Unless otherwise specified, the raw materials used in the examples are all conventional commercial products; and the equipment used are all conventional equipment unless otherwise specified.

[0046] In the examples, methacrylated gelatin (molecular weight 100-200 kDa) was purchased from Aladdin Co., Ltd. Ti3AlC2MAX was purchased from Fushan Information Technology Co., Ltd.

[0047] Example 1

[0048] Preparation of an α-lipoic acid liposome photothermal responsive hydrogel coating that can inhibit scarring and promote wound healing:

[0049] (1) Before preparing the α-lipoic acid liposome hydrogel coating, the PET substrate was ultrasonically cleaned to remove impurities on the surface and dried with clean air.

[0050] (2) The PET substrate was plasma treated in a vacuum (pressure of 10 Pa) at a power of 10 W for 5 minutes, and then immersed in a 3 wt% KH570 solution (the solvent is a mixture of ethanol and water, wherein the volume ratio of ethanol to water is 1:1) at room temperature for 2 hours (the amount of KH570 solution used is sufficient to immerse the PET substrate). The PET substrate was taken out and dried at room temperature to obtain a KH570-treated PET substrate.

[0051] (3) The KH570-treated PET substrate was placed in an ethyl acetate solution containing 1 wt% ethyl (2,4,6-trimethylbenzoyl) phenyl phosphate (TPO-L). The amount of ethyl (2,4,6-trimethylbenzoyl) phenyl phosphate (TPO-L) ethyl acetate solution was sufficient to submerge the PET substrate. The PET substrate was then removed and dried after the solvent evaporated to obtain an initiator-treated PET substrate. As the solvent evaporated, a stable initiator layer formed on the surface of the PET substrate.

[0052] (4) The initiator-treated PET substrate was immersed in a hydrogel precursor solution, which was a dispersion of GeLMA, PSBMA, α-lipoic acid liposome suspension, Ti3AlC2 MAX and water, wherein the mass ratio of GeLMA, PSBMA, α-lipoic acid liposome and Ti3AlC2 MAX was 10:5:2.5:0.1; the mass ratio of Ti3AlC2 MAX to the above-mentioned water was 1 mg / mL.

[0053] α-Lipoic acid liposomes consist of α-lipoic acid and a lipid membrane coating the surface of the α-lipoic acid. The lipid membrane is composed of soybean lecithin and cholesterol. The α-lipoic acid liposome suspension was prepared using the thin film hydration method. The following steps were performed: soybean lecithin and cholesterol were weighed in a 2:1 mass ratio (total mass 0.168 g) and dissolved together with 0.05 g of α-lipoic acid in 20 mL of dichloromethane. The mixture was then placed in a round-bottom flask. The dichloromethane was evaporated using a rotary evaporator at 40°C, forming a uniform, thin lipid film on the inner wall of the flask. The lipid film was then hydrated with 30 mL of phosphate buffered saline (PBS) at pH 7.4 at the same temperature. The hydration process was as follows: ultrasonic treatment at 40°C (ultrasonic power 200 W) for 5 minutes; then, the flask was placed in an ice-water bath and probe sonicated (40% amplitude, 20 minutes). During sonication, the probe tip was slightly below the liquid surface (immersion depth approximately 3-5 mm). Finally, the obtained liposome dispersion was filtered through a 0.45 μm filter membrane to obtain a uniform liposome suspension, which was stored at 4°C.

[0054] (5) The reaction was allowed to proceed at room temperature for 30 seconds under ultraviolet light irradiation (1000W) until an initiation layer was formed. The α-lipoic acid liposome hydrogel coating was then allowed to stand at room temperature (without ultraviolet light irradiation) for 10 seconds. The free radicals generated by the oil-soluble TPO-L initiator promoted the growth of the hydrogel coating from the surface of the PET substrate, thereby forming a uniform and stable α-lipoic acid liposome hydrogel coating.

[0055] Example 2

[0056] A preparation of an α-lipoic acid liposome photothermal responsive hydrogel coating that can inhibit scarring and promote wound healing is as described in Example 1, except that: in step (4), the concentration of Ti3AlC2MAX is 0.5mg / ml (the mass ratio of Ti3AlC2MAX to the volume of water); the other steps and conditions are the same as in Example 1.

[0057] Example 3

[0058] A photothermal responsive α-lipoic acid liposome hydrogel coating capable of inhibiting scarring and promoting wound healing is prepared as described in Example 1, except that in step (4), the concentration of Ti3AlC2MAX is 0.1mg / ml (the mass ratio of Ti3AlC2MAX to the volume of water); the other steps and conditions are the same as in Example 1.

[0059] Comparative Example 1

[0060] An α-lipoic acid liposome hydrogel coating was prepared as described in Example 1, except that Ti3AlC2 MAX was not added to the hydrogel precursor solution in step (4); the other steps and conditions were the same as in Example 1.

[0061] Comparative Example 2

[0062] An α-lipoic acid liposome hydrogel coating is prepared as described in Example 1, except that: in step (4), no α-lipoic acid liposome suspension is added to the hydrogel precursor solution; other steps and conditions are the same as in Example 1.

[0063] Comparative Example 3

[0064] An α-lipoic acid liposome hydrogel coating was prepared as described in Example 1, except that in step (4), no α-lipoic acid liposome suspension and Ti3AlC2 MAX were added to the hydrogel precursor solution; the other steps and conditions were the same as in Example 1.

[0065] Comparative Example 4

[0066] An α-lipoic acid liposome hydrogel coating was prepared as described in Example 1, except that in step (4), no PSBMA, α-lipoic acid liposome suspension, and Ti3AlC2 MAX were added to the hydrogel precursor solution; the other steps and conditions were the same as in Example 1.

[0067] Test Example 1

[0068] Rheological Measurement of α-Lipoic Acid Liposome Hydrogel Coating

[0069] like Figure 1 As shown, the mechanical properties of the α-lipoic acid liposome hydrogel coating were determined at the microscale through rheological experiments. A strain amplitude sweep was performed in the experiment, with the strain increasing from 1% to 1000%. Within the linear strain range of 3%, the storage modulus (G') and loss modulus (G") of the α-lipoic acid liposome hydrogel coating of Comparative Example 1 (Ge@PS-L) were both greater than those of the hydrogel coating of Comparative Example 3 (Ge@PS). The results indicate that hydrogen bonds between the α-lipoic acid liposomes and the hydrogel network significantly improve the mechanical properties of the α-lipoic acid liposome hydrogel coating.

[0070] Test Example 2

[0071] Stability and durability test of α-lipoic acid liposome hydrogel coating

[0072] Comparative Example 1: α-lipoic acid liposome hydrogel coating is applied to the surface of PET material (ie, the substrate is PET), and PET material is easy to bend. Figure 2 and Figure 3 As shown in Figure 2, the material was subjected to a bending test with 10,000 cycles or an ultrasonic cleaning for 24 hours (ultrasonic power of 400W). Figure 4As shown, there was no significant change in the bending position and the water contact angle of the α-lipoic acid liposome hydrogel coating surface before and after bending and ultrasonic cleaning.

[0073] Test Example 3

[0074] Hemolysis test of fresh rat erythrocytes coated with α-lipoic acid liposome hydrogel

[0075] The biocompatibility of the hydrogel samples of Example 1 (Ge@PS-L-MX), Comparative Example 2 (Ge@PS-MX) and Comparative Example 3 (Ge@PS) was evaluated by their hemolytic ability on fresh rat red blood cells. Figure 5 As shown in (a), the sample was co-cultured with red blood cells for 24 hours and then centrifuged. The supernatant of the positive control group (0.1% Triton X-100) was a distinct blood red, while the supernatant of the hydrogel sample group remained transparent and colorless. The absorbance of the supernatant was measured, and the hemolysis rates of the hydrogel samples were calculated to be 2.18%, 3.05%, and 0.5%, respectively (corresponding to Example 1 (Ge@PS-L-MX), Comparative Example 2 (Ge@PS-MX), and Comparative Example 3 (Ge@PS), respectively), all below 5%. These results indicate that the sample has good blood compatibility.

[0076] Test Example 4

[0077] CCK-8 Detection of α-Lipoic Acid Liposome Hydrogel Coating

[0078] The CCK-8 assay was used to evaluate the number of viable cells during quantitative proliferation in the hydrogel samples of Example 1 (Ge@PS-L-MX), Comparative Example 2 (Ge@PS-MX), and Comparative Example 3 (Ge@PS). Figure 5 As shown in Figures 5(b) and 5(c), compared with the groups of Comparative Examples 2 and 3, the viability and proliferation of DF cells in the Example 1 group were significantly reduced. The proliferation ability was strongest in the Comparative Example 2 group. The number of surviving DF cells in the Example 1 group was only two-thirds of that in the Comparative Example 2 and 3 groups. In addition, Figure 5 As shown in Figures 5(d) and 5(e), compared with Comparative Examples 2 and 3, the ROS level of DF cells in Example 1 was significantly reduced, being half of that in the groups of Comparative Examples 2 and 3. The ROS levels of DF cells in Comparative Examples 2 and 3 were both around 0.7, with very little difference. The ROS level of DF cells in Comparative Example 2 was slightly higher than that in Comparative Example 3. This indicates that Example 1 can significantly reduce oxidative stress.

[0079] Test Example 5

[0080] Immunofluorescence staining to quantitatively determine the expression levels of COL1A1 and MKi67 in α-lipoic acid liposome hydrogel coatings

[0081] like Figure 5 (f) Quantification of COL1A1 and MKi67 expression levels by immunofluorescence staining: COL1A1, a key extracellular matrix (ECM) component, is significantly elevated in hypertrophic scar fibroblasts compared to healthy skin fibroblasts, highlighting its potential as a biomarker for skin fibrosis. Furthermore, MKi67 is a proliferation marker specifically upregulated in activated fibroblasts during skin scarring. Representative images show that compared to the Comparative Example 2 (Ge@PS-MX) and Comparative Example 3 (Ge@PS) groups, the expression of COL1A1 and MKi67 in the Example 1 (Ge@PS-L-MX) group was significantly reduced. The fluorescence expression of COL1A1 in Comparative Example 2 was stronger than that in Comparative Example 3, while the fluorescence expression of MKi67 was weaker in Comparative Example 2 than in Comparative Example 3. ROS levels were significantly elevated in Comparative Example 2 and Comparative Example 3, with ROS levels in Comparative Example 2 slightly weaker than in Comparative Example 3, with a small difference in fluorescence intensity. This suggests that oxidative stress may exacerbate the fibrotic process. These findings indicate that LA can inhibit cell proliferation and attenuate ROS accumulation, suggesting its potential efficacy in inhibiting fibrotic scar formation.

[0082] Test Example 6

[0083] Effects of α-lipoic acid liposome hydrogel coating on wound healing and fibrotic remodeling

[0084] A full-thickness excisional wound model was established in mice (n=8 / group) to systematically evaluate the effects of the hydrogels of Comparative Example 2 (Ge@PS-MX) and Comparative Example 3 (Ge@PS) as well as Example 1 (Ge@PS-L-MX) on wound healing and fibrotic remodeling. In the experiment, the hydrogels were applied to the wound site.

[0085] Figure 6 (a) is a schematic diagram of the full-thickness excision model of mouse wounds. Figure 6 (b) is the immunofluorescence staining image of MYHI1+ on the 5th and 10th day after injury (wherein the first row of pictures is taken on the 5th day after injury, and the second row of pictures is taken on the 10th day after injury), 6(c) is the immunofluorescence staining image of MKi67+ (proliferating cells) on the 5th and 10th day after injury (wherein the first row of pictures is taken on the 5th day after injury, and the second row of pictures is taken on the 10th day after injury), 6(d) is the immunofluorescence staining image of CNN1+ (smooth muscle cells) on the 5th and 10th day after injury (wherein the first row of pictures is taken on the 5th day after injury, and the second row of pictures is taken on the 10th day after injury). Figure 6As shown in Figures 6(b), 6(c) and 6(d), 5 days after injury, the fluorescence intensity of αSMA and MKi67+ cells in Example 1 group was significantly higher than that in Comparative Example 3 group. These results indicate that MXene activates myofibroblasts and accelerates their proliferation through local photothermal effect under NIR irradiation (in the test experiment, NIR continuous irradiation was performed immediately after the hydrogel was applied to the wound, with an NIR irradiation power of 0.839W, a wavelength of 350nm, and an irradiation time of 600s). In Comparative Example 2 group, the density of vascular smooth muscle cells (MYH11+ or CNN1+ cells) and endothelial cells (CD31+ cells) increased synchronously, indicating that the mild thermal stimulation induced by MXene enhanced the angiogenesis ability. In addition, as Figure 6 As shown in (f), compared with the Example 1 group, the mRNA levels of fibrosis-related genes (Col1a1, Col3a1, Co3a1, Postn, Ctgf) in the Comparative Example 2 group were significantly increased, further confirming its pro-fibrotic characteristics. At the same time point (5 days), the expression levels of inflammatory factors (Mcp1, Tnfa, IL6) in the Example 1 group were lower, indicating that LA alleviated excessive inflammatory response through its antioxidant and anti-inflammatory effects. Compared with the Comparative Example 2 and Comparative Example 3 groups, the Example 1 group showed obvious regulatory characteristics on the 5th day. These characteristics include a significant decrease in the fluorescence intensity of MYH11+ and MKi67+ cells, and a decrease in the expression levels of genes related to fibrosis. In addition, the CD31 cell density in this group continued to increase, accompanied by an increase in CNN1+ cells. This observation indicates that LA promotes the maturation of new blood vessels by promoting endothelial-smooth muscle cell interactions rather than simply stimulating vascular proliferation. As Figure 6 (e) Quantitative analysis showed that Example 1 group had the lowest number of CD45+ and MKi67+ cells on days 5 and 10, respectively. Compared with Comparative Examples 2 and 3, Comparative Example 2 group had the highest number of MKi67+ cells on days 5 and 10, Comparative Example 2 group had the highest number of CD45+ cells on day 5, and Comparative Example 3 group had the highest number of CD45+ cells on day 10. This indicates that the addition of α-lipoic acid liposomes in Example 1 can gradually release and significantly inhibit the growth of mouse skin scars, promote angiogenesis, and thus significantly promote wound healing.

[0086] Test Example 7

[0087] Antibacterial properties of α-lipoic acid liposome hydrogel coating

[0088] A hydrogel coating was prepared on the surface of surgical sutures (the preparation method was the same as that of Example 1 and Comparative Example 4, except that the substrate was replaced with surgical sutures) to study the anti-adhesion properties of the hydrogel coatings prepared by the methods of Example 1 and Comparative Example 4 against Staphylococcus aureus. Figure 7As shown on the left, the four groups of culture medium comparison pictures are the adhesion comparison of Staphylococcus aureus on the surface of blank surgical suture (blank sample), hydrogel coating-coated surgical suture (GelMA) prepared by the method of Comparative Example 4 without NIR irradiation, α-lipoic acid liposome hydrogel coating-coated surgical suture (Ge@PS-L-MX1) prepared by the method of Example 1 without NIR irradiation, and α-lipoic acid liposome hydrogel coating-coated surgical suture (NIR irradiated Ge@PS-L-MX1) prepared by the method of Example 1 under NIR irradiation conditions (NIR irradiation at the initial stage of culture, power of 0.839W, wavelength of 350nm, irradiation time of 600s). As shown Figure 7 As shown on the right, the adhesion rates of Staphylococcus aureus on a blank suture, a suture coated with Comparative Example 4, a suture coated with Example 1 without NIR irradiation, and a suture coated with Example 1 under NIR irradiation were 100%, 25%, 7.5%, and 2.5%, respectively. The antibacterial experiment demonstrated that the α-lipoic acid liposome hydrogel coating of Example 1 can prevent bacterial adhesion. Under NIR irradiation, the bacterial adhesion rate of the α-lipoic acid liposome hydrogel coating of Example 1 was further reduced to 2.5%. This is because MXene can absorb light energy under NIR irradiation and convert it into heat energy, resulting in an increase in the surface temperature of the coating. This temperature increase not only controls the release of the drug but also effectively kills bacteria attached to the surface.

[0089] Test Example 8

[0090] Experimental study on lubricity of α-lipoic acid liposome hydrogel coating

[0091] like Figure 8 As shown in (a), Figure 8 (a) is a schematic diagram of the method for measuring the friction coefficient of the hydrogel coatings of Comparative Example 1, Comparative Example 3, and Comparative Example 4 using a rheometer. Figure 8 (b) and Figure 8 (c) is the friction coefficient of the hydrogel coating of Comparative Example 4 (GelMA), Comparative Example 3 (Ge@PS) and Comparative Example 1 (Ge@PS-L) under the conditions of a friction speed of 30 rad / min and a normal load of 1 N, which are 0.01, 0.007 and 0.002 respectively. The introduction of PSBMA and α-lipoic acid liposomes reduces the friction coefficient of the α-lipoic acid liposome hydrogel coating of Comparative Example 1 by 5 times compared with the hydrogel coating of Comparative Example 4. This is because the sulfonated betaine groups in PSBMA establish hydrogen bonds with water molecules to form a dense hydration layer; in addition, the phospholipid bilayer of the α-lipoic acid liposome is an amphiphilic structure, which is conducive to the formation of a self-lubricating layer, and the lubrication performance of the liposome will decrease if liposomes are replaced with lipoic acid. The presence of a dense hydration layer and a self-lubricating layer reduces the friction coefficient of the α-lipoic acid liposome hydrogel coating of Comparative Example 1 and improves its wear resistance. As shown in FIG. Figure 8 As shown in (d), Figure 8 (d) The friction coefficients of the hydrogel coatings of Example 1 (Ge@PS-L-MX1) and Comparative Example 1 (Ge@PS-L) were measured using a rheometer at a constant normal force of 1 N and a constant rotation speed of 30 rad / min. The friction performance of the hydrogel coatings with and without MXene introduction was compared, and the effect on the friction coefficient was not significant.

[0092] Test Example 9

[0093] Photothermal performance test of α-lipoic acid liposome hydrogel coating

[0094] like Figure 9 (a) and 9(b), Figure 9 (a) Recorded the NIR irradiation (0.839W, 350nm) of Comparative Example 1 (Ge@PS-L-MX0), Example 3 (Ge@PS-L-MX 0.1 ), Example 2 (Ge@PS-L-MX 0.5 ) and Example 1 (Ge@PS-L-MX1) α-lipoic acid liposome hydrogel coating temperature changes over time. After 600s of NIR irradiation, the temperatures of the α-lipoic acid liposome hydrogel coatings in Comparative Example 1, Example 3, Example 2, and Example 1 were 30.5°C, 45°C, 58°C, and 68°C, respectively. Figure 9 (b) shows infrared thermal images of Comparative Example 1 and Example 1 under NIR irradiation (0.839 W, 350 nm) for 1 minute, 2 minutes, 4 minutes, and 6 minutes. This shows that the photothermal conversion efficiency of the α-lipoic acid liposome hydrogel coating significantly improves with increasing MXene content. However, if the MXene content is higher than 1 mg / ml, it will overheat under NIR irradiation.

[0095] The above-described embodiments merely represent implementation methods of the present invention and should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art may make various modifications and improvements without departing from the scope of the present invention, all of which fall within the scope of protection of the present invention.

Claims

1. A method for preparing an α-lipoic acid liposome photothermal responsive hydrogel coating that can inhibit scarring and promote wound healing, comprising the steps of: (1) Plasma-treating the substrate, then immersing it in a 3-(trimethylsilyl)propyl methacrylate (KH570) solution, and drying it to obtain a KH570-treated substrate; (2) The KH570-treated substrate was immersed in an ethyl acetate solution of ethyl (2,4,6-trimethylbenzoyl) phenyl phosphate (TPO-L) and dried to obtain an initiator-treated substrate; (3) immersing the substrate treated with the initiator in a hydrogel precursor solution to obtain an α-lipoic acid liposome photothermal responsive hydrogel coating that can inhibit scarring and promote wound healing; The hydrogel precursor solution is a dispersion of methacrylated gelatin (GeLMA), polymethacrylate sulfobetaine (PSBMA), α-lipoic acid liposomes, Ti3AlC2 MAX and water.

2. The method for preparing the α-lipoic acid liposome photothermal responsive hydrogel coating capable of inhibiting scarring and promoting wound healing according to claim 1, characterized in that: In step (1), the substrate material is selected from polyethylene terephthalate or high-density polyethylene.

3. The method for preparing the α-lipoic acid liposome photothermal responsive hydrogel coating capable of inhibiting scarring and promoting wound healing according to claim 1, characterized in that: In step (1), one or more of the following conditions are included: i. Before the plasma treatment, the following steps are also included: ultrasonic cleaning of the substrate to remove impurities on the surface and drying in clean air; ii. The conditions for plasma treatment are: pressure 5-20 Pa, power 5-20 W, and plasma treatment time 3-8 minutes, preferably 5 minutes.

4. The method for preparing the α-lipoic acid liposome photothermal responsive hydrogel coating capable of inhibiting scarring and promoting wound healing according to claim 1, characterized in that: In step (1), the solvent used for the 3-(trimethyloxysilyl)propyl methacrylate (KH570) solution is a mixture of ethanol and water, wherein the volume ratio of ethanol to water is 1-2:1; the content of 3-(trimethyloxysilyl)propyl methacrylate in the 3-(trimethyloxysilyl)propyl methacrylate (KH570) solution is 1-5wt%; preferably, in step (1), the immersion temperature is room temperature and the immersion time is 1-5h.

5. The method for preparing the α-lipoic acid liposome photothermal responsive hydrogel coating capable of inhibiting scarring and promoting wound healing according to claim 1, characterized in that: In step (2), the concentration of the ethyl (2,4,6-trimethylbenzoyl) phenyl phosphate (TPO-L) ethyl acetate solution is 1-5 wt %; preferably, in step (2), the immersion temperature is room temperature and the immersion time is 20-40 s.

6. The method for preparing the α-lipoic acid liposome photothermal responsive hydrogel coating capable of inhibiting scarring and promoting wound healing according to claim 1, characterized in that: In step (3), the α-lipoic acid liposomes are composed of α-lipoic acid and a lipid membrane coated on the surface of the α-lipoic acid, and the lipid membrane is composed of soybean lecithin and cholesterol; the α-lipoic acid liposomes are added to the system in the form of an α-lipoic acid liposome suspension, wherein the solvent of the α-lipoic acid liposome suspension is a phosphate buffer solution with a pH of 7.4, and the concentration of the α-lipoic acid liposomes is 7-7.5 g / L; Preferably, in step (3), the preparation method of the α-lipoic acid liposome suspension is a thin film hydration method, comprising the steps of: dissolving soybean lecithin, cholesterol and α-lipoic acid in dichloromethane, removing dichloromethane by rotary evaporation to form a uniform thin lipid film; adding phosphate buffered saline (PBS) for hydration treatment; then ultrasonically and filtering to obtain the α-lipoic acid liposome suspension; further preferably, the mass ratio of soybean lecithin to cholesterol is 1-3:1, and the mass ratio of the total mass of soybean lecithin and cholesterol to α-lipoic acid is 3-4:1; the volume ratio of the mass of α-lipoic acid to dichloromethane is 2-3 g / L; the rotary evaporation temperature is 40°C; the pH of the phosphate buffer is 7.4, and the volume ratio of the mass of α-lipoic acid to the phosphate buffer is 1.5-2 g / L; the hydration method is as follows: ultrasonic treatment at 35-45°C for 3-10 min, and then ultrasonic treatment at -5-5°C for 15-25 min; the specification of the filter membrane is 0.45 μm.

7. The method for preparing the α-lipoic acid liposome photothermal responsive hydrogel coating capable of inhibiting scarring and promoting wound healing according to claim 1, characterized in that: In step (3), the mass ratio of methacrylated gelatin (GeLMA), polymethacrylate sulfobetaine (PSBMA), α-lipoic acid liposomes, and Ti3AlC2 MAX is 8-12:4-8:2-3:0.01-0.2, preferably 10:5:2-3:0.01-0.1, and more preferably 10:5:2.5:0.

1.

8. The method for preparing the α-lipoic acid liposome photothermal responsive hydrogel coating capable of inhibiting scarring and promoting wound healing according to claim 1, characterized in that: In step (3), one or more of the following conditions are included: i. The mass ratio of Ti3AlC2 MAX to water is 1-5 mg / mL; ii. The reaction conditions are as follows: react under UV light for 20-50 seconds, then remove the UV light and let it stand at room temperature for 5-50 seconds; the UV light power is 800-1200W.

9. An α-lipoic acid liposome photothermal responsive hydrogel coating capable of inhibiting scarring and promoting wound healing, prepared by the method according to any one of claims 1 to 8.

10. Use of the α-lipoic acid liposome photothermal responsive hydrogel coating capable of inhibiting scarring and promoting wound healing according to any one of claims 1 to 8 in the preparation of a drug or dressing capable of inhibiting scarring and promoting wound healing.

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