Mussel mucin hydrogel dressing with self-repairing function, preparation method and application thereof

Abstract

This application discloses a mussel mucin hydrogel dressing with self-repairing function and its preparation method. The dressing comprises a gel system comprising a composite hydrogel matrix and a functionalized nano-modified component. The composite hydrogel matrix comprises a network structure formed by photoenzyme-assisted crosslinking of mussel mucin, methacryloylated gelatin, and phenylboronic acid-modified gelatin. The weight ratio of the mussel mucin, methacryloylated gelatin, and phenylboronic acid-modified gelatin is (2-5):(15-20):5. The functionalized nano-modified component comprises mesoporous silica nanoparticles loaded with small molecule polypeptides and graphene oxide, wherein the graphene oxide accounts for 0.1-0.5 parts by weight in the gel system; the mesoporous silica nanoparticles account for 1-3 parts by weight in the gel system, and the polypeptide loading rate is 30-50%. This application addresses the shortcomings of traditional wound repair materials in terms of adhesion stability, antibacterial properties, and anti-inflammatory properties.

Description

Technical Field

[0001] The present invention relates to the technical field of biological excipients, and in particular to a mussel mucin hydrogel dressing with self-repairing function, a preparation method thereof, and applications thereof. Background Art

[0002] Hydrogels are polymeric materials with a three-dimensional network structure, formed through physical or chemical bonding in aqueous solution. They possess hydrophilic groups, allowing them to swell in water or body fluids without dissolving. This unique structure endows hydrogels with numerous excellent properties, making them promising for wound dressing applications. Hydrogels also exhibit excellent biocompatibility, meaning they are less likely to induce adverse reactions such as inflammation when in contact with human tissue.

[0003] Since the 1960s, researchers have confirmed this property by injecting hydrogels into experimental subjects for the treatment of bone and joint injuries. Its biodegradability is also excellent. Through modification or compounding, high-performance biodegradable hydrogels can be produced. These hydrogels have great application potential in implants and drug delivery, and can effectively address safety issues such as rejection of interventional materials and poor metabolism of drug delivery systems. Hydrogels also have high water absorption and water retention, with a water content of up to 99%. Medical dressings made from hydrogels can absorb wound exudate while maintaining a moist environment, avoiding adhesion to the wound and causing secondary trauma. They also absorb a large amount of fluid and do not require frequent replacement. Furthermore, the hydrogel surface is smooth and highly elastic, allowing it to adhere closely to the wound when used as a dressing without adhesion, reducing bacterial contact.

[0004] Despite the significant advantages of hydrogel dressings, the existing technology still has many shortcomings. In terms of breathability, existing hydrogel dressings have limited breathability, which may affect gas exchange at the wound site and be detrimental to wound healing. For example, after covering the wound, some traditional hydrogel dressings will cause the wound to be locally in a relatively closed state, resulting in the skin being unable to breathe normally and possibly causing problems such as skin maceration. Poor environmental adaptability is also a prominent problem. Some hydrogel dressings have difficulty maintaining stable performance in special environments such as extreme temperatures. For example, in low-temperature environments, some hydrogel dressings may become brittle, lose elasticity, and fail to fit the wound well. In terms of antibacterial properties, long-term use of some hydrogel dressings may cause bacteria to develop drug resistance. For some hydrogel dressings with added antibacterial agents, as the use time increases, bacteria may adapt to the antibacterial components therein, reducing the antibacterial effect. Moreover, current hydrogel dressings have limitations in drug selection, and it is difficult to achieve effective loading and release for certain special drugs or treatment needs. When absorbing wound exudate, existing hydrogel wound dressings adhere to the skin and swell, causing the wound to stretch and expand. This not only causes pain to the patient, but also increases the risk of bacterial infection due to the expansion of the wound area.

[0005] Mussels are able to firmly adhere to various surfaces in the humid and complex marine environment thanks to their secreted mussel mucin. Incorporating mussel mucin into hydrogels significantly improves the adhesion of the hydrogel to wound tissue. Compared to conventional hydrogel dressings, hydrogels infused with mussel mucin adhere more tightly to the wound and are less likely to shift or fall off, even during patient activity. This ensures consistent and effective wound care and reduces the risk of bacterial invasion due to loosening of the dressing. Mussel mucin contains dopa groups, which promote cell adhesion, spreading, and proliferation. When used as a hydrogel component, it provides a favorable microenvironment for wound cells. Studies have shown that hydrogels containing mussel mucin significantly accelerate the proliferation of cells closely involved in wound healing, such as fibroblasts, helping to accelerate the wound healing process, shorten the healing period, and reduce the likelihood of scarring. Mussel mucin has antimicrobial properties and can effectively inhibit the growth of common wound pathogens. This antibacterial effect does not rely solely on killing bacteria, but rather on interfering with the bacterial adhesion mechanism, preventing bacteria from colonizing the wound surface, thereby reducing the chance of wound infection and creating a clean environment for wound healing. Therefore, incorporating mussel mucin into hydrogel dressings can effectively address the problem of hydrogel dressings lacking antibacterial properties. However, after mussel mucin is prepared into a hydrogel, its adhesion is also affected in a wet environment. In addition, since hydrogel dressings need to have a certain mechanical strength to support the wound while maintaining sufficient flexibility to adapt to the movement and deformation of the skin, the addition of mussel mucin will affect the mechanical properties of the hydrogel. Therefore, the main problem that needs to be solved is to ensure that the adhesion of mussel mucin in the hydrogel is long-lasting and maintain good mechanical properties. Summary of the Invention

[0006] In order to overcome the deficiencies of the prior art, the purpose of this application is to provide a mussel mucin hydrogel dressing with self-repairing function to solve the defects of traditional wound repair materials in adhesion stability and antibacterial and anti-inflammatory properties.

[0007] To solve the above problems, the technical solutions adopted in this application are as follows:

[0008] The present application provides a mussel mucin hydrogel dressing with self-repairing function, including a gel system, wherein the gel system includes a composite hydrogel matrix and a functionalized nano-modified component;

[0009] The composite hydrogel matrix is ​​a network structure formed by mussel mucin, methacryloylated gelatin and phenylboronic acid modified gelatin through light-enzyme synergistic crosslinking, wherein the weight ratio of the mussel mucin, methacryloylated gelatin and phenylboronic acid modified gelatin is (2-5): (15-20): 5;

[0010] The functionalized nano-modified component includes mesoporous silica nanoparticles loaded with small molecule polypeptides and graphene oxide, wherein the graphene oxide accounts for 0.1-0.5 parts by weight in the gel system; the mesoporous silica nanoparticles account for 1-3 parts by weight in the gel system, and the polypeptide loading rate is 30-50%.

[0011] As a further preferred embodiment, the gel system described in the embodiment of the present application also includes auxiliary components, which include a moisturizer, a temperature-responsive polymer and deionized water, wherein the moisturizer is 5-10 parts, the temperature-responsive polymer is 2-4 parts, and the deionized water is 30-80 parts by weight; the amount of the auxiliary components added to the gel system is 8-12 parts by weight.

[0012] As a further preferred embodiment, the small molecule polypeptide described in the embodiment of the present application is a mixture of one or more of GD peptide, EGF, and VEGF; the moisturizer is a mixture of one or more of glycerol, sorbitol, hyaluronic acid, trehalose, polyethylene glycol, and aloe polysaccharide; and the temperature-responsive polymer is a mixture of one or more of poly(N-isopropylacrylamide), poly[di(ethylene glycol) methacrylate], polyvinyl caprolactam, and polyethylene oxide-polypropylene oxide block copolymer.

[0013] As a further preferred solution, the functional modification component described in the embodiment of the present application further includes ε-polylysine-PLGA microspheres, and the ε-polylysine-PLGA microspheres form a fiber membrane with a hydrophobic network structure on the surface of the gel system.

[0014] As a further preferred solution, the gel system described in the embodiment of the present application further includes a pH-responsive fluorescent probe, which is dispersed in the hydrogel in the form of microcapsules.

[0015] The present application also provides a method for preparing a mussel mucin hydrogel dressing with self-repairing function, comprising:

[0016] Preparation of mixed hydrogel prepolymer solution: Dissolve methacrylated gelatin and phenylboronic acid modified gelatin in PBS respectively and mix them in proportion, add photoinitiator and disperse them evenly to obtain hydrogel prepolymer solution;

[0017] Mesoporous silica loaded with polypeptides: a small molecule polypeptide solution is mixed with nano-mesoporous silica, and vacuum impregnation is performed to allow the small molecule polypeptide to be adsorbed into the pores of the mesoporous silica. After treatment, the mixture is freeze-dried to obtain mesoporous silica nanoparticles loaded with small molecule polypeptides;

[0018] Functionalization modification of hybrid hydrogel: adding the above-mentioned peptide-loaded mesoporous silica nanoparticles to a hydrogel prepolymer solution, and dispersing and homogenizing the solution by ultrasonic treatment in cold water to obtain a functionalized hydrogel prepolymer solution;

[0019] Preparation of a mussel mucin premix: mussel mucin is dissolved in PBS to obtain a mussel mucin solution, graphene oxide is evenly dispersed in the mussel mucin solution to form a stable suspension, and then a catalytic enzyme is added and evenly dispersed to obtain a mussel mucin premix;

[0020] Photo-enzyme synergistic reaction: The functionalized modified hydrogel prepolymer solution and the mucin premix solution are mixed in proportion, irradiated with blue light for photopolymerization to form a primary network, and then incubated to complete the enzyme-catalyzed reaction to obtain a composite hydrogel with a network structure.

[0021] As a further preferred embodiment, the method for preparing the mussel mucin hydrogel dressing with self-repairing function described in the embodiment of the present application further includes spraying ε-polylysine-PLGA microspheres on the surface of the composite hydrogel to form a surface hydrophobic network layer of ε-polylysine, and the specific steps are as follows:

[0022] Preparation of ε-polylysine-PLGA microspheres: PLGA is first dissolved in ethyl acetate to prepare an oil phase; ε-polylysine is then dissolved in an aqueous acetic acid solution to obtain an aqueous phase; the aqueous phase is slowly dripped into the oil phase and homogenized in an ice bath to form a primary emulsion; the primary emulsion is added to a PBS solution containing polyvinyl alcohol and homogenized to obtain an emulsion; the emulsion is stirred to evaporate the ethyl acetate, and the microspheres are collected by centrifugation, washed with deionized water, freeze-dried, and sieved to retain microspheres with a particle size of 1.5-2.5 μm;

[0023] Spraying microspheres to form a surface hydrophobic network layer: The microspheres are dispersed in an ethanol solution containing Tween 80, and then sprayed onto the surface of the composite hydrogel using a high-pressure airless spray gun. Hot air annealing is then performed to melt the surface of the microspheres and embed them into the surface layer of the dressing.

[0024] The weight ratio of ε-polylysine to PLGA is 1:(3-5).

[0025] As a further preferred embodiment, the method for preparing the mussel mucin hydrogel dressing with self-repairing function described in the embodiment of the present application further comprises the step of adding auxiliary components:

[0026] Dissolving a moisturizing agent in deionized water to obtain a moisturizing solution; then adding a temperature-responsive polymer to pure water at 0-5°C and stirring with a magnetic stirrer to form a uniform sol; then heating the sol to 20-25°C and adding the moisturizing solution dropwise to obtain an auxiliary composition;

[0027] The auxiliary composition is added to the functionalized modified hydrogel prepolymer solution, and ultrasonically treated in an ice bath for 10-20 minutes until the mixture is uniformly dispersed.

[0028] As a further preferred embodiment, in the preparation method described in the embodiment of the present application, when preparing the mussel mucin premix, the graphene oxide is evenly dispersed in the mussel mucin liquid by ultrasound-centrifugation to form a stable suspension, the ultrasonic power is 280-350 W, and the time is 25-35 minutes; the amount of catalytic enzyme added is calculated according to the mass of mussel mucin and is 100-300 U / g.

[0029] As a further preferred embodiment, the photoinitiator described in the embodiments of the present application is LAP and / or Na-TPO (sodium phenyl-2,4,6-trimethylbenzoylphosphonate), and the catalytic enzyme is one or a mixture of two or more of laccase, tyrosinase, transglutaminase, and lysozyme.

[0030] Compared with the prior art, the present invention has the following beneficial effects:

[0031] 1. The self-healing mussel mucin hydrogel dressing described herein combines mussel mucin, methacryloylated gelatin, and phenylboronic acid-modified gelatin. The network structure formed by photoenzyme-mediated crosslinking imparts unique self-healing capabilities to the hydrogel dressing. This self-healing property automatically restores the integrity of the dressing when damaged, maintaining continuity and effectiveness of wound coverage, reducing the frequency of dressing changes and promoting wound healing. By adjusting the ratio of mussel mucin, methacryloylated gelatin, and phenylboronic acid-modified gelatin, the gel system's stability and strength are maintained, while also ensuring good biocompatibility and adhesion. This helps ensure a close fit between the dressing and wound tissue, promoting cell proliferation and wound healing.

[0032] 2. The self-healing mussel mucin hydrogel dressing described in this application incorporates functionalized nanostructured components, including mesoporous silica nanoparticles loaded with small-molecule peptides and graphene oxide. The peptide-loaded mesoporous silica nanoparticles not only provide additional structural support but also promote wound repair and regeneration through the loaded small-molecule peptides, ensuring the effective release of their bioactive properties and helping to accelerate the wound healing process. The trace addition of graphene oxide significantly enhances the hydrogel's electrical conductivity and mechanical strength while maintaining good biocompatibility. This helps promote microcurrent activity at the wound site, further promoting cell growth and tissue repair.

[0033] 3. The self-healing mussel mucin hydrogel dressing described in this application uses phenylboronic acid to modify gelatin, with phenylboronic acid-catechol dynamic covalent bonds replacing some chemical crosslinkers, imparting self-healing capabilities to the hydrogel. Graphene oxide enhances the adhesion of mussel mucin through π-π stacking. In a further embodiment, the surface of the composite hydrogel is sprayed with ε-polylysine / PLGA microspheres, forming a hydrophobic, antibacterial outer layer that effectively blocks bacterial invasion.

[0034] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0036] Figure 1 This is an SEM image of the mussel mucin hydrogel dressing with self-repairing function described in Example 1 of the present application.

[0037] Figure 2 This is an SEM image of the mussel mucin hydrogel dressing with self-repairing function described in Example 2 of the present application.

[0038] Figure 3 This is an SEM image of the mussel mucin hydrogel dressing with self-repairing function described in Example 3 of the present application.

[0039] Figure 4 This is a diagram of the appearance of the mussel mucin hydrogel dressing with self-repairing function described in an embodiment of the present application. DETAILED DESCRIPTION

[0040] To make the purpose, technical solutions, and advantages of the embodiments of this application more clear, the technical solutions in the embodiments of this application will be clearly and completely described below in conjunction with the drawings in the embodiments of this application. Obviously, the described embodiments are part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0041] The term "comprising" and other equivalent descriptions in the description and claims of this application are intended to cover non-exclusive inclusions, including both the contents clearly described in the description and claims and the steps or units that are not described in the description and claims but are inherent in the product, method or structure.

[0042] An embodiment of the present application provides a mussel mucin hydrogel dressing with self-repairing function, including a gel system, wherein the gel system includes a composite hydrogel matrix and a functionalized nano-modified component; the composite hydrogel matrix is ​​a network structure formed by mussel mucin, methacryloylated gelatin and phenylboronic acid-modified gelatin through light-enzyme synergistic crosslinking, and the weight ratio of the mussel mucin, methacryloylated gelatin and phenylboronic acid-modified gelatin is (2-5): (15-20): 5; the functionalized nano-modified component includes mesoporous silica nanoparticles loaded with small molecule polypeptides and graphene oxide, wherein the graphene oxide accounts for 0.1-0.5 parts by weight in the gel system; the mesoporous silica nanoparticles account for 1-3 parts by weight in the gel system, and the polypeptide loading rate is 30-50%. In the composite hydrogel matrix described in the examples of the present application, methacryloylated gelatin (GelMA) forms a stable covalent network through photoinitiated polymerization, while the boronate bonds of phenylboronic acid-modified gelatin (Gel-PBA) are dynamically reversible. The two work together to construct a dual-network structure that is both rigid and flexible. The boronate bonds can reversibly break and recombine when damaged, thereby achieving dynamic repair of the internal structure of the material and extending the service life of the dressing. The phenylboronic acid groups can reversibly bind to substances such as glucose in wound exudate, giving the gel pH responsiveness and optimizing the moist environment. Mussel mucin (MAP) is rich in catechol groups and can tightly adhere to the tissue surface through hydrogen bonding, π-π stacking, and other effects. At the same time, it participates in the formation of a dynamic network and improves the overall mechanical strength. Furthermore, in the examples of this application, synergistic enhancement is achieved by adding functionalized nanocomposite components. The high surface area mesoporous structure of MSNs enables efficient loading of small molecule peptides (such as antimicrobial peptides or growth factors), which are slowly released in the wound microenvironment (e.g., weakly acidic or enzyme-triggered). The released peptides can inhibit bacterial biofilm formation (e.g., antimicrobial peptides) or activate cell migration / proliferation signaling pathways (e.g., RGD peptides), accelerating wound repair. Graphene oxide (GO) has a nanosheet structure that can achieve broad-spectrum antimicrobial effects by physically cleaving bacterial membranes and reducing oxidative stress (generating reactive oxygen species). Its electrical conductivity can also promote intercellular electrical signaling, accelerating epidermal regeneration. GO, as a nanofiller, is embedded in the gel network, increasing tensile strength (approximately 1.5-3 times) and toughness through hydrogen bonding and π-π interactions. In the above scheme, the weight ratio of mussel mucin, methacryloylated gelatin (GelMA), and phenylboronic acid-modified gelatin significantly affects the performance of the hydrogel dressing.For example, mussel mucin has excellent adhesion and biocompatibility, allowing it to adhere tightly to wounds, reducing infection risk and promoting wound healing. However, an excessively high ratio can lead to a decrease in the mechanical properties of the gel. When forming a network structure, increasing the GelMA weight ratio improves the hydrogel's tensile strength, toughness, and other mechanical properties. An appropriate GelMA ratio facilitates good cross-linking, thereby enhancing the hydrogel's overall performance. An appropriate amount of phenylboronic acid-modified gelatin can significantly enhance the hydrogel's self-healing ability. To achieve a balanced and optimized balance of adhesion, biocompatibility, mechanical properties, and self-healing function, in the examples of this application, the weight ratio of mussel mucin, methacrylated gelatin, and phenylboronic acid-modified gelatin is (2-5):(15-20):5. In a preferred embodiment, the weight ratio of mussel mucin, methacrylated gelatin, and phenylboronic acid-modified gelatin is 4:20:5. Graphene oxide can enhance the adhesive properties of mussel mucin through π-π stacking. Graphene oxide (GO) contains oxygen-containing functional groups and can act as a physical crosslinker, hydrogen bonding with -COOH groups in the gel system. This increases the crosslink density and intermolecular forces of the hydrogel, enhancing its tensile strength and elongation at break, and improving its overall mechanical properties. Therefore, when preparing hydrogel dressings, appropriately increasing the GO content can enhance their mechanical stability, making them more suitable for applications requiring resistance to certain external forces or pressures. Furthermore, the addition of GO can significantly improve the thermal stability and elastic recovery of hydrogel dressings. In dynamically covalently crosslinked hydrogel systems, graphene oxide (GO) acts as both a reinforcing agent (mechanical and electrical conductivity) and a functional carrier (antimicrobial and photothermal responsiveness). Small changes in its mass fraction can significantly impact the key properties of the dressing. When the GO mass fraction is too low, the rigidity of the GO skeleton is weakened, the hydrogel storage modulus decreases, and the tensile strength of the dressing is reduced. Furthermore, insufficient carboxyl groups on the GO surface participate in the dynamic covalent bonding of phenylboronic acid, compromising the network's self-healing efficiency. However, excessive use of graphene oxide (GO) can also have numerous negative effects. For example, excessive GO filling can result in a hydrogel with a smaller pore size, hindering oxygen and nutrient penetration, inhibiting cell migration, and increasing the exposure of GO's active edges (oxygen-containing functional groups), leading to decreased fibroblast survival. Therefore, in the examples of this application, the amount of graphene oxide in the gel system is controlled to 0.1-0.5 parts by weight; in some preferred embodiments, the amount of graphene oxide in the gel system is 0.2-0.4 parts by weight.

[0043] Furthermore, the gel system described in the embodiments of this application also includes auxiliary components, including a moisturizer, a temperature-responsive polymer, and deionized water. The moisturizer comprises 5-10 parts by weight, the temperature-responsive polymer comprises 2-4 parts by weight, and the deionized water comprises 50-80 parts by weight. The auxiliary components are added to the gel system in an amount of 8-12 parts by weight. The small molecule polypeptide is a mixture of one or more of GD peptide, EGF, and VEGF. The moisturizer is a mixture of one or more of glycerol, sorbitol, hyaluronic acid, trehalose, polyethylene glycol, and aloe polysaccharide. In some embodiments, glycerol is added to the hydrogel dressing. Glycerol can form hydrogen bonds with water molecules through its hydroxyl groups to increase water absorption, while also lowering the hydrogel's glass transition temperature and improving its flexibility. However, excessive amounts can result in a sticky feeling and interfere with the oxidative crosslinking efficiency of mussel mucin. Therefore, in the gel system described in the embodiments of this application, Sorbitol has low viscosity and maintains high porosity, making it suitable for highly exudative wounds. It also scavenges free radicals and prolongs the activity of polypeptides. In a preferred embodiment, sorbitol is combined with glycerol (3:2 by volume) to effectively balance moisture retention and breathability. Hyaluronic acid has excellent water retention and can activate CD44 receptors to promote fibroblast migration. It can dynamically bind to the phenylboronic acid bonds of GelPB in the gel system, enhancing network stability. However, excessive use can reduce the gel crosslink density, so it is not recommended for use in the gel system. In the embodiments of this application, auxiliary components of the moisturizing agent may also include trehalose, polyethylene glycol, and aloe polysaccharide. Trehalose acts as a biomolecular protectant, stabilizing the polypeptide conformation through a "water displacement" mechanism. Polyethylene glycol is primarily used for film formation and osmotic pressure regulation, forming a semipermeable membrane on the wound surface to inhibit bacterial adhesion. Aloe polysaccharide has dual anti-inflammatory and moisturizing properties, effectively inhibiting the growth of Gram-positive bacteria and reducing the area of ​​erythema. In the embodiments of the present application, a temperature-responsive polymer is also added to the auxiliary components. Temperature-responsive polymers are a class of intelligent polymer materials that can respond to changes in external temperature. These polymers exhibit a lower critical solution temperature (LCST), also known as a cloud point (CT), in aqueous solution. When the temperature is below the LCST, the polymer chains become hydrophilic, dissolve in water, and expand in volume. When the temperature is above the LCST, the polymer chains become hydrophobic, undergo phase separation, curl the chains, and shrink in volume. The temperature-responsive polymer can be selected from one or a mixture of two or more of poly(N-isopropylacrylamide), poly(di(ethylene glycol) methacrylate), polyvinyl caprolactam, and polyethylene oxide-polypropylene oxide block copolymers. In the embodiments of the present application, by precisely controlling the amounts and ratios of the moisturizer, temperature-responsive polymer, deionized water, and small molecule peptides, the performance of the hydrogel dressing can be finely controlled and optimized, improving the overall performance of the hydrogel dressing while also meeting the needs of different wound types and healing stages.

[0044] Furthermore, on the basis of the above scheme, the functional modification component described in the embodiment of the present application also includes ε-polylysine-PLGA microspheres, and the ε-polylysine-PLGA microspheres are sprayed on the surface of the gel system to form a fiber membrane with a hydrophobic network structure, that is, an antibacterial outer layer. In combination with the above scheme, the mussel mucin hydrogel dressing described in the embodiment of the present application can form a biomimetic structure, specifically including a hydrophobic network layer formed by ε-polylysine-PLGA microspheres as an outer antibacterial layer to block bacterial invasion; the mesoporous silica nanoparticles loaded with small molecule polypeptides are assembled in the network structure formed by the light-enzyme synergistic crosslinking of mussel mucin, methacryloylated gelatin and phenylboronic acid modified gelatin to form a shrinkage scaffold layer located in the middle to ensure that the pores remain stable under mechanical stress; the π-π stacking effect of mussel mucin and graphene oxide and the DOPA oxidation crosslinking form a strong adhesion interface to form a high adhesion matrix layer.

[0045] As a further preferred embodiment, based on the above embodiments, in some embodiments, a pH-responsive fluorescent probe is further added to the gel system. The pH-responsive fluorescent probe is dispersed in the hydrogel in the form of microcapsules. Specifically, the pH-responsive fluorescent probe is a microencapsulated bromocresol green derivative, with a shell material of calcium alginate and a wall thickness of 0.5-1 μm. When the pH is greater than 7, the fluorescence emission peak red-shifts from 515 nm to 620 nm.

[0046] The present application also provides a method for preparing a mussel mucin hydrogel dressing with self-repairing function, comprising:

[0047] Preparation of a mixed hydrogel prepolymer solution: Dissolve methacrylated gelatin and phenylboronic acid-modified gelatin in PBS, respectively, mix the dissolved methacrylated gelatin and phenylboronic acid-modified gelatin in proportion, add a photoinitiator and disperse evenly to obtain a hydrogel prepolymer solution;

[0048] Mesoporous silica loaded with polypeptides: A small molecule polypeptide solution is mixed with nano-mesoporous silica, and vacuum impregnation is performed to allow the small molecule polypeptide to be adsorbed into the pores of the mesoporous silica. After completion, freeze-drying is performed to obtain mesoporous silica nanoparticles loaded with small molecule polypeptides;

[0049] Functionalization modification of hybrid hydrogel: adding the above-mentioned peptide-loaded mesoporous silica nanoparticles to a hydrogel prepolymer solution, and dispersing and homogenizing the solution by ultrasonic treatment in cold water to obtain a functionalized hydrogel prepolymer solution;

[0050] Preparation of a mussel mucin premix: mussel mucin is dissolved in PBS to obtain a mussel mucin solution, graphene oxide is evenly dispersed in the mussel mucin solution to form a stable suspension, and then a catalytic enzyme is added and evenly dispersed to obtain a mussel mucin premix;

[0051] Photo-enzyme synergistic reaction: The functionalized modified hydrogel prepolymer solution and the mucin premix solution are mixed in proportion, irradiated with blue light for photopolymerization to form a primary network, and then incubated to complete the enzyme-catalyzed reaction to obtain a composite hydrogel with a network structure.

[0052] In a specific embodiment of the present application, to prepare a mixed hydrogel prepolymer, methacrylated gelatin and phenylboronic acid-modified gelatin were separately dissolved in PBS at a pH of 7.0-7.5 in a water bath at 30-40°C to prevent gelatin deformation and maintain a viscosity of 500-800 mPa·s. The photoinitiator was used in an amount of 0.1% to 0.3% by weight of the gel system. Preferably, after obtaining the hydrogel prepolymer, air bubbles were removed by vacuum centrifugation at 1800-2500 rpm for 8-15 minutes to avoid structural defects after curing. In some preferred embodiments, when loading peptides onto mesoporous silica, the small molecule peptide and nano-mesoporous silica are mixed in a weight ratio of (0.5-1.0):2. The mesoporous silica has a pore size of 4-6 nm and a specific surface area of ​​800-1000 m² / g. Vacuum impregnation conditions are: -0.1 MPa, 20-27.5°C, and oscillation adsorption for 10-15 hours. Freeze-drying uses a combination of pre-freezing and freeze-drying steps: pre-freezing at -80°C for 20-25 hours, followed by vacuum freeze-drying at 0.1 Pa for 20-25 hours, with a residual moisture content of ≤2%. In specific embodiments of this application, when functionalizing the hybrid hydrogel, ultrasonic treatment uses probe sonication at 180-250W for 25-35 minutes, with the cold water temperature controlled at ≤25°C, and a particle size distribution CV of ≤15%. In the preparation method described in the embodiment of the present application, when preparing the mussel mucin premix, the graphene oxide is uniformly dispersed in the mussel mucin liquid by ultrasound-centrifugation to form a stable suspension. The graphene oxide sheet size is 200-500nm. The ultrasound is carried out in a water bath at a temperature of ≤25°C to prevent overheating and protein denaturation. The ultrasonic power is 280-350W and the time is 25-35 minutes. The amount of catalytic enzyme added is 50-100U / mL. The enzyme solution is prepared and used immediately and stored at 4°C for ≤6 hours to avoid inactivation. In the embodiment of the present application, during the light-enzyme synergistic reaction, 405nm, 10mW / cm² blue light is used for 50-70 seconds, the incubation condition is a constant temperature and humidity box at 37°C, the reaction time is 1.5-2.5 hours, and the humidity is ≥90% to prevent dehydration.

[0053] Furthermore, based on the above scheme, in some embodiments, the method for preparing the mussel mucin hydrogel dressing with self-repairing function described in the embodiments of the present application further includes spraying ε-polylysine-PLGA microspheres on the surface of the composite hydrogel to form a surface hydrophobic network layer of ε-polylysine, and the specific steps are as follows:

[0054] Preparation of ε-polylysine-PLGA microspheres: first dissolve PLGA in ethyl acetate to prepare an oil phase; then dissolve ε-polylysine in an acetic acid aqueous solution to obtain an aqueous phase; slowly drip the aqueous phase into the oil phase and homogenize in an ice bath to form a primary emulsion; add the primary emulsion to a PBS solution containing polyvinyl alcohol and homogenize to obtain an emulsion; stir the emulsion and evaporate the ethyl acetate; collect the microspheres after centrifugation, wash with deionized water, freeze-dry, and sieve to retain microspheres with a particle size of 1.5-2.5 μm; in this step, when PLGA is dissolved in ethyl acetate, magnetic stirring is used to promote dissolution; the magnetic stirring conditions are: 500 -800 rpm, 25-30°C, 1.5-2.5 hours, the concentration of PLGA after dissolution is 10-15% w / v; when ε-polylysine is dissolved in aqueous acetic acid, ultrasound-assisted dissolution is used under the following ultrasound conditions: frequency 35-45 kHz, power 100-150 W, time 10-20 minutes, the concentration of ε-polylysine after dissolution is 2-4% w / v; the process of forming the primary emulsion is carried out in a water bath at a temperature of ≤10°C, the aqueous phase is added at a rate of 0.3-0.8 mL / min, and a homogenizer is used to accelerate dispersion during the addition process, with a homogenizer speed of 10,000-12,000 rpm;

[0055] Spraying microspheres to form a surface hydrophobic network layer: The microspheres are dispersed in an ethanol solution containing Tween 80, and then sprayed onto the surface of the composite hydrogel using a high-pressure airless spray gun. Hot air annealing is then performed to melt the surface of the microspheres and embed them into the surface layer of the dressing.

[0056] The weight ratio of ε-polylysine to PLGA is 1:(3-5).

[0057] As a further preferred embodiment, the method for preparing the mussel mucin hydrogel dressing with self-repairing function described in the embodiment of the present application further comprises the step of adding auxiliary components:

[0058] Dissolving a moisturizing agent in deionized water to obtain a moisturizing solution; then adding a temperature-responsive polymer to pure water at 0-5°C and stirring with a magnetic stirrer to form a uniform sol; raising the temperature of the sol to 20-25°C and adding the moisturizing solution dropwise to obtain an auxiliary composition;

[0059] The auxiliary composition is added to the functionalized modified hydrogel prepolymer solution, and ultrasonically treated in an ice bath for 10-20 minutes until the mixture is uniformly dispersed.

[0060] Furthermore, in some embodiments, the photoinitiator used is LAP or / and Na-TPO (sodium phenyl-2,4,6-trimethylbenzoylphosphonate). LAP is compatible with 405 nm blue light, preventing UV damage to bioactive components, and offers high initiation efficiency. Its degradation products are lactic acid and pyruvic acid, with low toxicity. Na-TPO exhibits deep-layer curing capabilities, making it suitable for thick hydrogels or tissue repair scaffolds. It also exhibits long-wavelength adaptability, responding to a broad spectrum of light from 365-420 nm. It exhibits high free radical activity and superior resistance to oxygen interference to LAP. In some embodiments, a mixture of LAP and Na-TPO (mixed in a 1:1 weight ratio) is used as the photoinitiator, combining rapid surface curing with deep penetration. In the present embodiments, the catalytic enzyme is one or a mixture of two or more of laccase, tyrosinase, transglutaminase, or lysozyme. Among them, laccase has DOPA oxidation specificity, efficiently catalyzing the oxidation of DOPA (DOPA) in mussel mucin to DOPAquinone, forming a covalent crosslinked network and promoting the construction of a dynamic crosslinked and self-repairing mussel mucin network. Laccase also has antibacterial properties, and its oxidation products inhibit bacterial biofilm formation. Tyrosinase catalyzes the hydroxylation and crosslinking of tyrosine / DOPA, adapting to collagen, silk fibroin, and other proteins. Its activity is stable at 25-37°C, preventing high-temperature cell damage. It can regulate melanin production and assist in aesthetic wound repair. Transglutaminase enhances the mechanical strength of gelatin / collagen networks through ε-(γ-glutamyl)lysine bonds. Lysozyme can cleave the cell walls of Gram-positive bacteria, achieving highly effective antibacterial properties. When used in combination with a photoinitiator, it can achieve simultaneous antibacterial and gelation effects. Preferably, in some embodiments, the catalytic enzyme is a combination of laccase and lysozyme in a 2:1 weight ratio, achieving simultaneous crosslinking and long-lasting antibacterial effects on mussel mucin. The amount of catalytic enzyme added is calculated based on the mass of mussel mucin and is 100-300 U / g.

[0061] Example 1

[0062] This example provides a self-healing mussel mucin hydrogel dressing, comprising a gel system comprising a composite hydrogel matrix, a functionalized nano-modified component, and auxiliary components. The composite hydrogel matrix comprises a network structure formed by photo-enzyme synergistic crosslinking of mussel mucin, methacryloylated gelatin, and phenylboronic acid-modified gelatin. The functionalized nano-modified component comprises mesoporous silica nanoparticles loaded with small-molecule peptides and graphene oxide. The specific components and amounts used in this example are shown in Table 1.

[0063] Table 1: Composition and dosage of the examples

[0064]

[0065] The preparation method of the mussel mucin hydrogel dressing with self-repairing function is as follows:

[0066] Prepare a mixed hydrogel prepolymer solution: add 20 g of GelMA to 100 mL of PBS (pH 7.4, 37°C) and stir in a water bath until dissolved (200 rpm, 30 min); dissolve 5 g of phenylboronic acid-modified gelatin in 50 mL of PBS (pH 7.4), stir in a 50°C water bath until dissolved, and then mix with the methacrylated gelatin solution; add 0.15 g of LAP and 0.15 g of Na-TPO, stir for 10 min until completely dissolved, and vacuum centrifuge to remove bubbles (2000 rpm, 10 min) to obtain a clear prepolymer solution;

[0067] Mesoporous silica loaded with polypeptides: 0.5 g of small molecule polypeptide (RGD polypeptide) was dissolved in 10 mL of deionized water, and 2 g of mesoporous silica nanoparticles (particle size 50-100 nm) were added. The small molecule polypeptide was adsorbed into the pores of the mesoporous silica by vacuum impregnation (vacuum impregnation conditions -0.1 MPa, 25°C, and oscillation for 12 h). After treatment, the mixture was pre-frozen at -80°C for 24 h and freeze-dried at 0.1 Pa for 24 h to obtain mesoporous silica nanoparticles loaded with small molecule polypeptides.

[0068] Preparation of an auxiliary composition: 5 g of glycerol and 3 g of sorbitol were dissolved in 30 g of deionized water to obtain a moisturizing solution; 2 g of PNIPAM was added to 10 mL of ice water (0-5°C) and magnetically stirred for 30 minutes to form a sol. The sol was heated to 25°C, and the moisturizing solution was added dropwise. After mixing, the mixture was ultrasonicated in an ice bath for 15 minutes (power 200 W) to obtain the auxiliary composition;

[0069] Functionalization modification of hybrid hydrogel: The peptide-loaded mesoporous silica nanoparticles were added to a hydrogel prepolymer solution, and the mixture was homogenized by ultrasonic treatment (ultrasonic power 250 W, time 20 min) in cold water (≤25°C). Then, 10 g of the auxiliary composition was added and stirred evenly to obtain a functionalized hydrogel prepolymer solution.

[0070] Preparation of mussel mucin premix: 4 g of mussel mucin freeze-dried powder was ultrasonically dispersed (300 W, 30 min, ≤ 25 ° C) in PBS to obtain a mussel mucin gel with a concentration of 10 mg / mL. 0.2 g of GO was added and the aggregates were removed by ultrasonic-centrifugation (3000 rpm, 10 min) to form a stable suspension. 400 U of laccase (freshly prepared enzyme solution, stored at 4 ° C for ≤ 6 h) was then added and mixed to obtain the mussel mucin premix.

[0071] Photoenzyme synergistic reaction: The functionalized hydrogel prepolymer solution and the mussel mucin premix were mixed and irradiated with blue light (405 nm, 10 mW / cm², 60 s) to form a primary network. The mixture was then transferred to a 37°C wet box (95% humidity) and incubated with enzymes for 2 h to obtain a composite hydrogel with a network structure.

[0072] Preparation of ε-polylysine-PLGA microspheres: 4 g of PLGA was dissolved in 40 mL of ethyl acetate (stirring speed 500 rpm, 25°C, 2 h) to prepare the oil phase; 1 g of ε-polylysine was dissolved in 10 mL of 1% acetic acid water (ultrasonication power 100 W) to prepare the aqueous phase; the aqueous phase was added dropwise to the oil phase (0.5 mL / min, ≤10°C), homogenized (10000 rpm, 10 min) to form an emulsion, and the emulsion was poured into 500 mL of PBS containing 2% PVA, homogenized (5000 rpm, 20 min), stirred to evaporate the solvent (4 h), and then centrifuged (8000 rpm, 15 min), washed with water, freeze-dried, and sieved (2 μm) to obtain microspheres;

[0073] Spraying microspheres to form a surface hydrophobic network layer: The microspheres were dispersed in 50% ethanol (containing 0.5% Tween80, concentration 10 mg / mL), and evenly sprayed onto the gel surface with a high-pressure spray gun (0.3 MPa) to a thickness of 30 μm. After hot air annealing (50°C, 30 min), the microspheres melted and embedded in the surface layer to form a surface hydrophobic network layer.

[0074] Figure 1 This is the SEM image of the mussel mucin hydrogel dressing with self-repairing function described in this embodiment. Figure 1 The mussel mucin hydrogel dressing exhibits a porous network structure with pores of varying sizes that are interconnected, forming a complex three-dimensional network. This porous structure provides the hydrogel dressing with a large specific surface area, facilitating material exchange with surrounding tissues. For example, it can better absorb wound exudate while also facilitating the delivery of nutrients and medications. The interconnected pores and network structure provide conditions for the hydrogel's self-repair. When the hydrogel is damaged, its internal molecular chains can interact through the pores, reentering and cross-linking to achieve self-repair. Mussel mucin itself has unique adhesive properties that can better function in this structure, helping the hydrogel reconnect at the site of injury.

[0075] Example 2

[0076] This example provides a self-healing mussel mucin hydrogel dressing, comprising a gel system comprising a composite hydrogel matrix, a functionalized nano-modified component, and auxiliary components. The composite hydrogel matrix comprises a network structure formed by photo-enzyme synergistic crosslinking of mussel mucin, methacryloylated gelatin, and phenylboronic acid-modified gelatin. The functionalized nano-modified component comprises mesoporous silica nanoparticles loaded with small-molecule peptides and graphene oxide. Specific components and amounts are shown in Table 2.

[0077] Table 2: Composition and dosage of Example 2

[0078]

[0079] The preparation method of the mussel mucin hydrogel dressing with self-repairing function is as follows:

[0080] Preparation of mixed hydrogel prepolymer solution: 15g GelMA was added to 120mL PBS (pH 7.2, 37°C) and stirred in a water bath until dissolved (speed 200 rpm, 30 min); 5g phenylboronic acid-modified gelatin was added to 50mL PBS (pH 7.4) and swelled, then dispersed in a 50°C water bath with magnetic stirring (300 rpm), deionized water was gradually added until transparent, and then mixed with methacryloyl gelatin solution; 0.2g Na-TPO was added and stirred for 15min until completely dissolved to obtain prepolymer solution, 0.1g fluorescent microcapsules were ultrasonically dispersed into the prepolymer solution (power 180W, 10min), and vacuum degassing was performed (1800rpm, 8min);

[0081] Mesoporous silica loaded with polypeptides: 1.5 g of a small molecule polypeptide (EGF) was dissolved in 15 mL of deionized water, and 3 g of mesoporous silica nanoparticles (particle size 50-100 nm) were added. The small molecule polypeptide was adsorbed into the pores of the mesoporous silica by vacuum impregnation (vacuum impregnation conditions: -0.1 MPa, 20°C, and oscillation for 15 h). After treatment, the mixture was pre-frozen at -80°C for 20 h and freeze-dried at 0.1 Pa for 20 h to obtain mesoporous silica nanoparticles loaded with small molecule polypeptides.

[0082] Preparation of an auxiliary composition: 4 g of hyaluronic acid and 4 g of trehalose were dissolved in 20 g of deionized water to obtain a moisturizing gel; 3 g of polyvinyl caprolactam was added to 10 mL of ice water (0-5°C), and magnetically stirred for 40 minutes to form a sol. The sol was heated to 20°C, and the moisturizing gel was added to the sol. The mixture was magnetically stirred and mixed, and then ultrasonicated in an ice bath for 10 minutes (power 200W) to obtain an auxiliary composition;

[0083] Functionalization modification of hybrid hydrogel: The peptide-loaded mesoporous silica nanoparticles were added to a hydrogel prepolymer solution, and the mixture was homogenized by ultrasonic treatment (ultrasonic power 250 W, time 20 min) in cold water (≤25°C). Then, 12 g of the auxiliary composition was added and stirred evenly to obtain a functionalized hydrogel prepolymer solution.

[0084] Preparation of mussel mucin premix: 2 g of mussel mucin freeze-dried powder was ultrasonically dispersed (300 W, 30 min, ≤ 25 ° C) in PBS to obtain a mussel mucin gel with a concentration of 5 mg / mL. 0.2 g of GO was added and the aggregates were removed by ultrasonic-centrifugation (3000 rpm, 10 min) to form a stable suspension. 400 U of laccase (freshly prepared enzyme solution, stored at 4 ° C for ≤ 6 h) was then added and mixed to obtain the mussel mucin premix.

[0085] Photoenzyme synergistic reaction: The functionalized hydrogel prepolymer solution and the mussel mucin premix were mixed and irradiated with blue light (405 nm, 10 mW / cm², 60 s) to form a primary network. The mixture was then transferred to a 37°C wet box (95% humidity) and incubated with enzyme for 2 h to obtain a composite hydrogel with a network structure.

[0086] Figure 2 This is an SEM image of the mussel mucin hydrogel dressing with self-repairing function described in Example 2. Figure 2 The film presents an interconnected three-dimensional porous structure. The white area is the hydrogel skeleton (containing mussel mucin and polymer cross-linking network), and the black area is the pore. The porous network allows the molecular chains at the damaged site (containing the adhesion groups of mussel mucin) to contact and reorganize with each other through the pores, thereby achieving repair with the help of the adhesion of mucin and the dynamic cross-linking of polymer chains.

[0087] Example 3

[0088] This example provides a self-healing mussel mucin hydrogel dressing, comprising a gel system comprising a composite hydrogel matrix, a functionalized nano-modified component, and auxiliary components. The composite hydrogel matrix comprises a network structure formed by photo-enzyme synergistic crosslinking of mussel mucin, methacryloylated gelatin, and phenylboronic acid-modified gelatin. The functionalized nano-modified component comprises mesoporous silica nanoparticles loaded with small-molecule peptides and graphene oxide. Specific components and amounts are shown in Table 3.

[0089] Table 3: Composition and dosage of Example 3

[0090]

[0091] The preparation method of the mussel mucin hydrogel dressing with self-repairing function is as follows:

[0092] Prepare a mixed hydrogel prepolymer solution: dissolve 18 g of GelMA and 5 g of phenylboronic acid-modified gelatin in 100 mL of PBS (pH 7.4, 40°C) and stir in a water bath until dissolved (200 rpm, 30 min). Add 0.2 g of LAP and stir until clear. Vacuum degassing (2500 rpm, 15 min) to obtain a clear prepolymer solution.

[0093] Mesoporous silica loaded with peptides: 0.3 g of small molecule peptide (LL-37 peptide) was dissolved in 10 mL of deionized water, and 1 g of mesoporous silica nanoparticles was added. The small molecule peptide was adsorbed into the pores of the mesoporous silica by vacuum impregnation (vacuum impregnation conditions: -0.1 MPa, 27.5°C, and shaking for 10 h). After treatment, the mixture was pre-frozen at -80°C for 24 h and freeze-dried at 0.1 Pa for 24 h to obtain mesoporous silica nanoparticles loaded with small molecule peptides.

[0094] Functionalization modification of hybrid hydrogel: The peptide-loaded mesoporous silica nanoparticles were added to a hydrogel prepolymer solution, and the solution was dispersed and homogenized by ultrasonic treatment (ultrasonic power 250 W, time 20 min) in cold water (≤25°C) to obtain a functionalized hydrogel prepolymer solution.

[0095] Preparation of mussel mucin premix: 5 g of mussel mucin freeze-dried powder was ultrasonically dispersed (300 W, 30 min, ≤ 25 ° C) in 20 mL of PBS. 0.2 g of GO was added to the obtained mussel mucin solution. Agglomerates were removed by ultrasonication-centrifugation (3000 rpm, 10 min) to form a stable suspension. 400 U of laccase (freshly prepared enzyme solution, stored at 4 ° C for ≤ 6 h) was then added and mixed to obtain the mussel mucin premix.

[0096] Photoenzyme synergistic reaction: The functionalized hydrogel prepolymer solution and the mussel mucin premix were mixed and irradiated with blue light (405 nm, 10 mW / cm², 60 s) to form a primary network. The mixture was then transferred to a 37°C wet box (95% humidity) and incubated with enzymes for 2 h to obtain a composite hydrogel with a network structure.

[0097] Preparation of ε-polylysine-PLGA microspheres: 3 g of PLGA was dissolved in 30 mL of ethyl acetate (stirring speed 800 rpm, 30°C, 1.5 h) to prepare the oil phase; 1 g of ε-polylysine was dissolved in 5 mL of 1% acetic acid water (ultrasonication power 150 W for 20 min) to prepare the aqueous phase; the aqueous phase was added dropwise to the oil phase (0.8 mL / min, ≤5°C) and homogenized (6000 rpm, 15 min) to form an emulsion, which was then poured into 600 mL of PBS containing 3% PVA and homogenized (6000 rpm, 15 min). The solvent was evaporated by stirring (4 h), and the microspheres were obtained after centrifugation (10000 rpm, 10 min), washing with water, freeze-drying, and sieving (2.5 μm).

[0098] Spraying microspheres to form a surface hydrophobic network layer: The microspheres were dispersed in 60% ethanol (containing 1% Tween80, concentration 15 mg / mL), and evenly sprayed onto the gel surface with a high-pressure spray gun (0.3 MPa) to a thickness of 50 μm. After hot air annealing (55°C, 25 min), the microspheres melted and embedded in the surface layer to form a surface hydrophobic network layer.

[0099] Figure 3 This is a SEM image of the mussel mucin hydrogel dressing with self-repairing function described in Example 3. Figure 3 The three-dimensional porous network structure can also be clearly seen.

[0100] Performance testing

[0101] The performance test of the mussel mucin hydrogel dressing with self-repairing function obtained in Example 1 was carried out. The specific test items and methods are as follows:

[0102] 1. Tensile and compression performance tests

[0103] The self-healing mussel mucin hydrogel dressing was dried in a 50°C oven to remove moisture, then cut into strips 50 mm long, 10 mm wide, and 3 mm thick. A Sterma S6 series electronic universal testing machine was used to perform tensile strength and compression tests. The strain rate was set to 50 mm / min, and five tests were performed each time, with the average value calculated.

[0104] 2. Adhesion strength (peel) test

[0105] After the mussel mucin hydrogel dressing with self-healing function was dried in an oven at 50°C to remove moisture, it was cut into strips 25 mm long, 20 mm wide, and 3 mm thick. The adhesion performance was tested on glass and polytetrafluoroethylene plates respectively on an electronic universal testing machine at a loading rate of 50 mm / min and a force of 100 N.

[0106] 3. Self-healing performance test

[0107] The mussel mucin hydrogel dressing with self-healing function was dried in a 50°C oven to remove moisture, and then cut into strips 25 mm long, 20 mm wide, and 10 mm thick. The strips were cut into two pieces with a blade and immediately brought into contact without external force. The self-healing process of the hydrogel was observed under a microscope, and the healing time after complete healing without visible cracks was recorded.

[0108] 4. Antibacterial activity test

[0109] The surface antibacterial activity of mussel mucin hydrogel was tested using Gram-positive bacteria Staphylococcus aureus (CICC 10145) and Gram-negative bacteria Escherichia coli (AB93154). The specific operation was to place the composite hydrogel in a 36-well plate and add 25µL of 1×10 7 CFU / mL bacterial dispersion was added to the surface of mussel mucin hydrogel and incubated at 37°C for 2 hours. The hydrogel surface was then rinsed with sterile saline to redisperse the bacteria. 100 µL of the test strain suspension was applied to LB solid medium and quickly and evenly spread using a sterile spreading rod. The suspension was incubated at 37°C for 24 hours, and the number of viable bacteria was recorded.

[0110] The performance test results of Examples 1-3 are shown in Table 4.

[0111] Table 4: Performance test of the hydrogel dressing described in Examples 1-3

[0112]

[0113] The above embodiments are only preferred embodiments of the present invention and cannot be used to limit the scope of protection of the present invention. Any non-substantial changes and replacements made by technicians in this field on the basis of the present invention fall within the scope of protection required by the present invention.

Claims

1. A mussel mucin hydrogel dressing with self-repairing function, characterized in that: The invention comprises a gel system, wherein the gel system comprises a composite hydrogel matrix and a functionalized nano-modified component; in The composite hydrogel matrix is ​​a network structure formed by mussel mucin, methacryloylated gelatin and phenylboronic acid modified gelatin through light-enzyme synergistic crosslinking, wherein the weight ratio of the mussel mucin, methacryloylated gelatin and phenylboronic acid modified gelatin is (2-5): (15-20): 5; The functionalized nano-modified component includes mesoporous silica nanoparticles loaded with small molecule polypeptides and graphene oxide, wherein the graphene oxide accounts for 0.1-0.5 parts by weight in the gel system; the mesoporous silica nanoparticles account for 1-3 parts by weight in the gel system, and the polypeptide loading rate is 30-50%; The preparation method of the mussel mucin hydrogel dressing with self-repairing function, The following steps are included: Preparation of mixed hydrogel prepolymer solution: Dissolve methacrylated gelatin and phenylboronic acid modified gelatin in PBS respectively and mix them in proportion, add photoinitiator and disperse them evenly to obtain hydrogel prepolymer solution; Mesoporous silica loaded with polypeptides: a small molecule polypeptide solution is mixed with nano-mesoporous silica, and vacuum impregnation is performed to allow the small molecule polypeptide to be adsorbed into the pores of the mesoporous silica. After treatment, the mixture is freeze-dried to obtain mesoporous silica nanoparticles loaded with small molecule polypeptides; Functionalization modification of hybrid hydrogel: adding the above-mentioned peptide-loaded mesoporous silica nanoparticles to a hydrogel prepolymer solution, and dispersing and homogenizing the solution by ultrasonic treatment in a cold water bath to obtain a functionalized hydrogel prepolymer solution; Preparation of a mussel mucin premix: mussel mucin is dissolved in PBS to obtain a mussel mucin solution, graphene oxide is evenly dispersed in the mussel mucin solution to form a stable suspension, and then a catalytic enzyme is added and evenly dispersed to obtain a mussel mucin premix; Photo-enzyme synergistic reaction: The functionalized modified hydrogel prepolymer solution and the mucin premix solution are mixed in proportion, irradiated with blue light for photopolymerization to form a primary network, and then incubated to complete the enzyme-catalyzed reaction to obtain a composite hydrogel with a network structure.

2. The mussel mucin hydrogel dressing with self-repairing function according to claim 1, characterized in that: The gel system also includes auxiliary components, which include a moisturizer, a temperature-responsive polymer, and deionized water. The moisturizer is 5-10 parts, the temperature-responsive polymer is 2-4 parts, and the deionized water is 30-80 parts by weight. The amount of the auxiliary components added to the gel system is 8-12 parts by weight.

3. The mussel mucin hydrogel dressing with self-repairing function according to claim 2, characterized in that: The small molecule polypeptide is one or a mixture of two or more of GD peptide, EGF, and VEGF; the moisturizer is one or a mixture of two or more of glycerol, sorbitol, hyaluronic acid, trehalose, polyethylene glycol, and aloe polysaccharide; and the temperature-responsive polymer is one or a mixture of two or more of poly(N-isopropylacrylamide), poly[di(ethylene glycol) methacrylate], polyvinyl caprolactam, and polyethylene oxide-polypropylene oxide block copolymer.

4. The mussel mucin hydrogel dressing with self-repairing function according to claim 1, characterized in that: The functionalized nano-modified component further comprises ε-polylysine-PLGA microspheres, and the ε-polylysine-PLGA microspheres form a fiber membrane with a hydrophobic network structure on the surface of the gel system.

5. The mussel mucin hydrogel dressing with self-repairing function according to any one of claims 1 to 4, characterized in that: The gel system further comprises a pH-responsive fluorescent probe, which is dispersed in the hydrogel in the form of microcapsules.

6. The mussel mucin hydrogel dressing with self-repairing function according to claim 1, characterized in that: The method further includes spraying ε-polylysine-PLGA microspheres on the surface of the composite hydrogel to form a surface hydrophobic network layer of ε-polylysine, and the specific steps are as follows: Preparation of ε-polylysine-PLGA microspheres: First, PLGA is dissolved in ethyl acetate; then, ε-polylysine is dissolved in aqueous acetic acid to obtain an aqueous phase; the aqueous phase is slowly dripped into the oil phase and homogenized in an ice bath to form a primary emulsion; the primary emulsion is added to a PBS solution containing polyvinyl alcohol and homogenized to obtain an emulsion; the emulsion is stirred to evaporate the ethyl acetate, and the microspheres are collected by centrifugation, washed with deionized water, freeze-dried, and sieved to retain microspheres with a particle size of 1.5-2.5 μm; Spraying microspheres to form a surface hydrophobic network layer: The microspheres are dispersed in an ethanol solution containing Tween 80, and then sprayed onto the surface of the composite hydrogel using a high-pressure airless spray gun. Hot air annealing is then performed to melt the surface of the microspheres and embed them into the surface layer of the dressing. The weight ratio of ε-polylysine to PLGA is 1:(3-5).

7. The mussel mucin hydrogel dressing with self-repairing function according to claim 1, characterized in that: It also includes the step of adding auxiliary components: Dissolving a moisturizing agent in deionized water to obtain a moisturizing solution; then adding a temperature-responsive polymer to pure water at 0-5°C and stirring with a magnetic stirrer to form a uniform sol; then heating the sol to 20-25°C and adding the moisturizing solution dropwise to obtain an auxiliary composition; The auxiliary composition is added to the functionalized modified hydrogel prepolymer solution, and ultrasonically treated in an ice bath for 10-20 minutes until the mixture is uniformly dispersed.

8. The mussel mucin hydrogel dressing with self-repairing function according to claim 7, characterized in that: When preparing the mussel mucin premix, the graphene oxide is evenly dispersed in the mussel mucin liquid by ultrasound-centrifugation to form a stable suspension. The ultrasonic power is 280-350W and the time is 25-35 minutes. The amount of catalytic enzyme added is 100-300U / g calculated based on the mass of the mussel mucin.

9. The mussel mucin hydrogel dressing with self-repairing function according to claim 7, characterized in that: The photoinitiator is LAP or / and Na-TPO, and the catalytic enzyme is one or a mixture of two or more of laccase, tyrosinase, transglutaminase and lysozyme.

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