Antioxidant sonodynamic hydrogel as well as preparation method and application thereof

Abstract

The invention relates to antioxidant sonodynamic hydrogel as well as a preparation method and application thereof, the yield and sonodynamic performance of ROS (reactive oxygen species) can be improved, and the prepared hydrogel can realize efficient antibiosis in the early stage of infection, exert antioxidant and repair promoting effects in the later stage of infection, and can promote angiogenesis and collagen deposition, optimize inflammation and immune microenvironment, improve the immunity of the ROS and improve the ROS yield and the sonodynamic performance of the ROS. The dynamic balance of antibiosis, antioxidation and healing promotion is realized, and the treatment effect is comprehensively improved.

Description

Technical Field

[0001] This invention relates to the field of biomedical materials technology, specifically to an antioxidant acoustic-dynamic hydrogel, its preparation method, and its application. Background Technology

[0002] In the field of wound treatment, effectively addressing the synergistic issue of infection control and tissue repair has always been a core direction in biomedical materials research and development. Ideal wound repair materials need to simultaneously possess highly efficient antibacterial capabilities, appropriate levels of reactive oxygen species (ROS) regulation, good antioxidant properties, and the ability to promote tissue regeneration, in order to meet the dynamic changes in wound healing from the infection phase to the healing phase.

[0003] Currently, titanium dioxide nanoparticles (TiO2 NPs) have attracted widespread attention in the fields of wound treatment and antibacterial applications due to their excellent antibacterial properties, and are used in products such as antibacterial coatings, wound dressings, and air purification. The most important antibacterial mechanism of TiO2 NPs is the generation of reactive oxygen species (ROS) during photocatalysis, which kills bacterial cell membranes by generating excess ROS. Secondly, TiO2 NPs have an excellent structure, which can be used to create targeted drug delivery systems, enhancing the effectiveness of various antibiotics. However, TiO2 nanoparticles typically rely on ultraviolet light excitation to generate ROS, and their generation efficiency is limited by light conditions. Furthermore, the continuous generation of reactive oxygen species can easily lead to excessive ROS, causing oxidative damage to surrounding healthy tissues and hindering wound healing. In addition, TiO2 has a wide band gap, and it can usually only be activated under ultraviolet light irradiation. However, ultraviolet light has poor penetration and potential tissue damage, limiting its application in deep wounds or in vivo. Moreover, the catalytic performance of traditional TiO2 nanoparticles is difficult to dynamically control once synthesized, making it impossible to flexibly adjust the ROS level according to the needs of different stages of wound healing. Moreover, TiO2 itself lacks antioxidant capacity and cannot effectively remove excess ROS, which may lead to oxidation imbalance during long-term use.

[0004] In addition, other types of antibacterial dressings and repair materials still have many limitations in clinical applications. Although traditional porphyrin-based antibacterial materials have certain acoustic or photosensitive properties, small molecule porphyrins have poor stability and are easily degraded and inactivated in complex wound environments, resulting in limited antibacterial efficiency. Moreover, they often only achieve a single bactericidal function and lack synergistic effects of antioxidation and promoting repair, making it difficult to meet the comprehensive needs of wound repair.

[0005] Therefore, developing a wound repair material that can achieve dynamic regulation of reactive oxygen species and has both high-efficiency antibacterial and antioxidant healing functions is of great significance for improving the treatment effect of wounds. Summary of the Invention

[0006] To address the aforementioned problems in the prior art, this invention provides a method for preparing an antioxidant sonodynamic hydrogel, which can improve ROS production and sonodynamic performance. The prepared hydrogel can achieve highly efficient antibacterial activity in the early stage of infection, exert antioxidant and repair-promoting effects in the later stage of infection, and can also promote angiogenesis, collagen deposition, and optimize the inflammatory and immune microenvironment.

[0007] The present invention provides the following technical solution.

[0008] A method for preparing an antioxidant sonodynamic hydrogel, characterized by comprising the following steps: Preparation of acoustically sensitive organic framework materials; The metal salt and the acoustic-sensitive organic framework material are mixed in a first solvent, followed by ultrasonication, heating, and drying to prepare a metal-doped organic framework material. An alkali and an antioxidant containing disulfide bonds or thiol groups are mixed in a second solvent to activate the disulfide bonds or thiol groups. Then, the mixture is mixed with the organic framework material of the doped metal to carry out cross-linking reaction and coordination to prepare the antioxidant sonodynamic hydrogel. The acoustically sensitive organic framework is selected from porphyrin-based covalent organic frameworks, metal porphyrin frameworks, phthalocyanine-based coordination polymers, metal phthalocyanine MOFs, supported porous silica-type porphyrin ultrasonic response materials, or supported graphene oxide-type porphyrin ultrasonic response materials. The metal in the metal salt includes osmium.

[0009] The preparation method described in this invention involves preparing a sonic-sensitive organic framework material, enhancing its sonic ROS production capacity by doping with osmium ions, and then activating an antioxidant containing disulfide bonds or thiol groups with an alkali. This antioxidant then undergoes a cross-linking reaction and coordination with the osmium-doped organic framework material, forming a stable hydrogel system. The cross-linking reaction tightly binds the antioxidant to the organic framework material, endowing the hydrogel with excellent mechanical properties and structural stability, providing a continuously moist microenvironment for the wound. The coordination effect strengthens the interaction between the osmium ions, the organic framework, and the antioxidant. This ensures the high efficiency of the sonic agent, enabling the generation of a large amount of ROS through ultrasound synergy in the early stages of infection to achieve a bactericidal rate greater than 95%, while also allowing for the stable release of the antioxidant. In the later stages, this effectively neutralizes residual ROS, reduces oxidative stress, and promotes angiogenesis, collagen deposition, and optimization of the immune microenvironment. Ultimately, this achieves a dynamic synergistic function of antibacterial, antioxidant, and healing-promoting effects, overcoming the shortcomings of traditional materials such as uncontrolled ROS generation and weak regulatory capabilities.

[0010] In one embodiment, the metal salt further includes one or more of ruthenium, iron, rhodium, iridium, and chromium.

[0011] In this invention, the metal salt also includes metal centers that can form coordination structures with porphyrins, such as ruthenium, iron, rhodium, iridium, and chromium. These metals can also enhance ROS generation activity under ultrasonic or photoacoustic excitation, and can form stable coordination structures with the sonosensitive organic framework, synergistically enhancing the peroxidase activity and sonodynamic properties of the sonosensitive organic framework. This ensures efficient generation of reactive oxygen species under ultrasonic excitation, guaranteeing a high bactericidal rate in the early stages of infection. Furthermore, the introduction of different metals provides more options for regulating the efficiency of reactive oxygen species generation, allowing for flexible adjustments based on specific wound needs, further optimizing the antibacterial effect.

[0012] In one embodiment, the metal salt is osmium chloride.

[0013] In this invention, osmium chloride possesses excellent water solubility and ionic stability, promoting the full dissolution and uniform dispersion of osmium ions in the first solvent (such as DMF). This ensures sufficient contact with the acoustically sensitive organic framework material. After ultrasonic treatment, uniform doping of metal ions can be achieved, avoiding abnormal coordination structures caused by excessively high local concentrations and ensuring the consistency of the performance of the doped organic framework material. Simultaneously, as a weak-field ligand, chloride ions, after binding with osmium ions, do not excessively occupy the coordination sites of osmium ions. This ensures that the formation of a stable and efficient core coordination structure between osmium ions and the acoustically sensitive organic framework is not affected, and that mild dissociation during the reaction does not interfere with subsequent cross-linking reactions with antioxidants. This effectively avoids side reactions that may be caused by other anions, thus ensuring the stability of the hydrogel system.

[0014] In one embodiment, the sonosensitive organic framework is a porphyrin-based covalent organic framework, which is prepared from a raw material containing a first organic ligand and a second organic ligand by a solvothermal method. Wherein, the first organic ligand is 5,10,15,20-tetra(4-aminophenyl)porphyrin; and / or the second organic ligand is 5,10,15,20-tetra(4-aldehydephenyl)porphyrin.

[0015] This invention uses 5,10,15,20-tetra(4-aminophenyl)porphyrin (TAPP) and 5,10,15,20-tetra(4-aldehydephenyl)porphyrin (TFPP) as building blocks. Both of these porphyrin ligands contain porphyrin rings in their molecular structures, possessing good conjugation systems and planar structures. This lays the foundation for forming a two-dimensional planar conjugated covalent organic framework, giving it a stable porous structure and excellent ultrasonic response performance, thereby improving ROS yield.

[0016] Furthermore, a porous polyporphyrin host was prepared using a solvothermal method with the first and second organic ligands. The constructed porphyrin-based covalent organic framework has a regular structure and high porosity, which not only facilitates the uniform doping of osmium ions, enhancing peroxidase activity and sonodynamic properties, but also provides sufficient contact sites for bacteria. Combined with the mechanical disturbance of ultrasound, it improves the bactericidal efficiency, ensuring a bactericidal rate of >95% in the early stage of infection. Simultaneously, this framework structure exhibits good compatibility with antioxidants containing disulfide bonds or thiol groups, and can stably bind during cross-linking reactions and coordination, ensuring the structural integrity of the hydrogel system. This allows for the stable release of antioxidants to neutralize residual ROS, promote angiogenesis, collagen deposition, and optimize the immune microenvironment, achieving a synergistic function of antibacterial and healing-promoting effects. Furthermore, the selection of specific porphyrin ligands ensures good biocompatibility of the framework, avoiding damage to normal tissues and further enhancing the application value of the hydrogel.

[0017] In one embodiment, the solvothermal method satisfies one or more of the following conditions: (1) The molar ratio of the first organic ligand to the second organic ligand is 1:(0.5~1.5); (2) The solvothermal method is carried out in an organic solvent, wherein the organic solvent is selected from one or more of dichlorobenzene and n-butanol; (3) The solvothermal method is carried out at a temperature of 100℃~140℃.

[0018] Understandably, in this invention, the molar ratio of the first organic ligand to the second organic ligand includes, but is not limited to, 1:0.5, 1:0.6, 1:0.7, 1:0.8, 1:0.9, 1:1, 1:1.1, 1:1.2, 1:1.3, 1:1.4, and 1:1.5.

[0019] In this invention, the aforementioned molar ratio range ensures sufficient reaction between the two organic ligands, reducing unreacted ligand residue. When the ratio falls within this range, the amino and aldehyde groups can achieve efficient condensation, avoiding framework structure defects caused by an excess of one organic ligand, thereby forming a well-structured porphyrin-based covalent organic framework with uniform pore distribution. This framework provides uniform sites for metal ion doping, ensuring stable acoustic and dynamic performance, while the ample porosity enhances contact efficiency with bacteria.

[0020] This invention selects dichlorobenzene and n-butanol as organic solvents, which exhibit good solubility for the first and second organic ligands, promoting uniform dispersion of the ligands and avoiding uneven polymerization caused by excessively high local concentrations. Simultaneously, dichlorobenzene and n-butanol maintain a stable reaction environment at the reaction temperature, promoting covalent bond formation and framework structure growth.

[0021] Understandably, in this invention, the solvothermal method is carried out at temperatures including but not limited to: 100°C, 102°C, 104°C, 106°C, 108°C, 110°C, 112°C, 114°C, 116°C, 118°C, 120°C, 122°C, 124°C, 126°C, 128°C, 130°C, 132°C, 134°C, 136°C, 138°C, and 140°C.

[0022] In this invention, the aforementioned temperature range provides sufficient energy for the ligand reaction, promoting the stable formation of covalent bonds and ensuring the integrity of the framework structure. If the temperature is too low, the reaction rate will be slow and incomplete, easily leading to a loose framework structure; if the temperature is too high, it may cause ligand decomposition or structural collapse.

[0023] In one embodiment, the antioxidant is selected from lipoic acid.

[0024] The disulfide bonds in lipoic acid molecules are easily activated under the action of alkali, enabling them to undergo efficient cross-linking reactions with osmium-doped organic framework materials. At the same time, the carboxyl groups of lipoic acid can form stable coordination with osmium ions, making the hydrogel structure more stable and possessing good mechanical properties and durability.

[0025] Furthermore, as a natural antioxidant, lipoic acid possesses strong antioxidant activity. It can not only eliminate excess residual ROS generated by sonodynamic processes in the early stages of infection, reducing oxidative stress damage to normal tissues, but also continuously regulate the wound microenvironment through stable release, protecting the proliferative activity of fibroblasts and endothelial cells and preventing secondary necrosis caused by excessive inflammation. In addition, the introduction of lipoic acid endows the hydrogel with moist healing properties, providing a suitable repair environment for the wound. Moreover, its good biocompatibility can synergistically promote angiogenesis and type III collagen deposition, optimize the wound immune microenvironment, and complement the antibacterial function of the sonosensitive organic framework, significantly enhancing the overall therapeutic effect of the hydrogel.

[0026] In one embodiment, the preparation method satisfies one or more of the following conditions: (1) The first solvent is selected from DMF; (2) The second solvent is selected from water; (3) The alkali is sodium bicarbonate; (4) The heating temperature is 100℃~140℃.

[0027] This invention selects DMF (N,N-dimethylformamide) as the first solvent, which has extremely strong dissolving power and can efficiently dissolve metal salts (such as osmium chloride) and acoustic-sensitive organic framework materials, ensuring uniform dispersion of the two during mixing and avoiding insufficient metal doping due to localized uneven concentration. Simultaneously, DMF's moderate polarity can stabilize the structure of the acoustic-sensitive organic framework, reducing aggregation or decomposition during ultrasonication and heating processes. This provides a suitable environment for the coordination reaction between osmium ions and the organic framework, ensuring the stability of the doped organic framework material's performance and thus enhancing the efficiency of subsequent acoustic dynamics-driven generation of reactive oxygen species.

[0028] This invention selects water as the second solvent because it has good biocompatibility and can avoid adverse effects on antioxidants containing disulfide bonds or thiol groups (such as lipoic acid) and metal-doped organic framework materials. Simultaneously, water, as a polar solvent, can promote the dissolution and ionization of alkalis (such as sodium bicarbonate), enhance the activation effect on disulfide bonds or thiol groups, and accelerate the cross-linking reaction and coordination with metal-doped organic framework materials. Furthermore, the resulting hydrogel possesses suitable hydrophilicity, providing a moist microenvironment for the wound, thereby promoting tissue repair.

[0029] Sodium bicarbonate, as a base, has a mild alkalinity. When activating disulfide bonds or thiol groups in antioxidants, it avoids the destruction of the antioxidant structure due to excessive alkalinity, thus ensuring the activity of the antioxidant. Simultaneously, the bicarbonate ions released from sodium bicarbonate in aqueous solution stabilize the pH of the reaction system, providing a suitable acid-base environment for cross-linking and coordination reactions, promoting orderly reaction and making the hydrogel structure more stable. Furthermore, sodium bicarbonate has good biocompatibility and does not introduce toxic or harmful substances, ensuring that the prepared hydrogel meets the safety requirements of biomedical materials and can be directly applied to wound treatment.

[0030] Understandably, in this invention, the heating temperature includes, but is not limited to, 100°C, 102°C, 104°C, 106°C, 108°C, 110°C, 112°C, 114°C, 116°C, 118°C, 120°C, 122°C, 124°C, 126°C, 128°C, 130°C, 132°C, 134°C, 136°C, 138°C, and 140°C.

[0031] In this invention, the aforementioned heating temperature range promotes the coordination and bonding of osmium ions with the organic framework, improves doping efficiency, ensures uniform and stable embedding of osmium ions into the organic framework, and enhances its acoustic-dynamic properties. If the temperature is too low, the reaction rate is slow and doping is insufficient, affecting the subsequent generation of reactive oxygen species; if the temperature is too high, the organic framework structure may be destroyed or metal ions may be precipitated.

[0032] In one embodiment, the activation of disulfide bonds or thiol groups is carried out at a temperature of 40°C to 50°C.

[0033] Understandably, in this invention, the activation temperature includes, but is not limited to, 40°C, 41°C, 42°C, 43°C, 44°C, 45°C, 46°C, 47°C, 48°C, 49°C, and 50°C.

[0034] In this invention, the aforementioned temperature range provides suitable energy conditions for the activation of disulfide bonds or thiol groups. If the temperature is too low, the activation reaction rate is slow, which may lead to insufficient activation of disulfide bonds or thiol groups. Conversely, if the temperature is too high, it may damage the molecular structure of the antioxidant, causing it to lose its antioxidant activity, and may also trigger unnecessary side reactions.

[0035] The cross-linking reaction and coordination were carried out at a temperature of 55℃~65℃.

[0036] Understandably, in this invention, the temperatures for crosslinking reactions and coordination effects include, but are not limited to, 55°C, 56°C, 57°C, 58°C, 59°C, 60°C, 61°C, 62°C, 63°C, 64°C, and 65°C.

[0037] In this invention, the aforementioned temperature range promotes the formation of stable cross-linked structures and coordination bonds between the activated antioxidant and the metal-doped organic framework material. If the temperature is too low, the reaction kinetics are insufficient, potentially leading to inadequate cross-linking and coordination, resulting in a loose hydrogel structure and poor mechanical properties. Conversely, if the temperature is too high, some of the existing bonds may break, or the material structure may be destroyed, affecting the stability and functionality of the hydrogel.

[0038] The present invention also provides an antioxidant sonodynamic hydrogel prepared by the preparation method described above.

[0039] The present invention also provides the antioxidant sonodynamic hydrogel described above for the preparation of materials for treating infected burn wounds.

[0040] The beneficial effects of this invention are reflected in the following aspects: By doping osmium metal ions into acoustically sensitive organic framework materials such as porphyrin groups, the peroxidase activity of the acoustically sensitive materials is significantly enhanced, and the efficiency of generating reactive oxygen species (ROS) through acoustic dynamics is greatly improved. This solves the problem of insufficient efficacy of traditional acoustically sensitive agents and ensures that a sterilization rate of >95% can be achieved under the synergy of ultrasound, effectively controlling pathogens in the early stages of infection.

[0041] Meanwhile, the stable structure formed by this osmium metal doping provides a good foundation for subsequent cross-linking and coordination reactions with alkali-activated antioxidants containing disulfide bonds or thiol groups. This makes the constructed hydrogel system not only structurally stable, providing continuous mechanical support and a moist microenvironment, but also able to dynamically remove residual ROS through antioxidants, avoiding oxidative stress damage to tissues, promoting angiogenesis and collagen deposition, and optimizing the inflammatory and immune microenvironment. This achieves an integrated treatment from highly effective antibacterial to antioxidant and healing-promoting effects, showing significant improvements in functional synergy and therapeutic efficacy compared to traditional materials.

[0042] Furthermore, by using a solvothermal method and other preparation processes to form an integrated hydrogel, the sonodynamic antibacterial and antioxidant repair-promoting functions can be synergistically exerted. Combined with the mechanical effect of ultrasound, it effectively promotes angiogenesis, type III collagen deposition and optimization of the immune microenvironment, achieving a dynamic balance of "antibacterial-antioxidant-promoting healing" and comprehensively improving the treatment effect. Attached Figure Description

[0043] Figure 1 This is a schematic diagram of an in vitro and in vivo experiment demonstrating the use of ultrasound in conjunction with polypor(M)@PLA to treat infected burn wounds on the skin. Figure 2 The image shows plate counts after polypor(Os)@PLA hydrogel was co-incubated with bacteria; where (a) represents the bactericidal rate of polypor(Os)@PLA after co-incubation with different bacteria; and (b) represents the plate coating after polypor(Os)@PLA was co-incubated with different bacteria. Figure 3 The images show the fluorescence staining of live and dead bacteria using SYTO-9 / PI; (a) represents the fluorescence staining of live and dead bacteria after co-incubation of polypor(Os)@PLA with different bacteria; (b) represents the ratio of live to dead bacteria after co-incubation with MRSA; (c) represents the ratio of live to dead bacteria after co-incubation with E. coli; * represents the control group, P<0.05; Figure 4 SEM images showing the morphological changes of each group of bacteria; Figure 5 A schematic diagram showing the DPPH removal efficiency of polypor(Os)@PLA hydrogel; Figure 6 A schematic diagram showing the O2⁻ scavenging efficiency of polypor(Os)@PLA hydrogel; Figure 7 (a) is a fluorescence image of DCFH-DA after co-incubation of hydrogel with HUVECs; (b) is a schematic diagram of fluorescence intensity analysis. Figure 8 A schematic diagram showing the ROS detection results in skin tissue of each group after treatment of burn wounds infected with MRSA. Figure 9 A schematic diagram showing the ROS detection results in skin tissue of each group after treatment of burn wounds infected with E. coli; Figure 10 A schematic diagram of Masson staining of tissue sections from burn wounds; where (a) represents the Masson trichrome staining image of burn wounds; (b) represents the CVF values ​​of each group of rabbit wounds infected with MRSA; and (c) represents the CVF values ​​of each group of rabbit wounds infected with E. coli. Figure 11 This is a schematic diagram of type III collagen in burn wound tissue; where (a) represents the fluorescent staining image of type III collagen in burn wound; (b) represents the fluorescence intensity value of type III collagen in each group of MRSA-infected rabbit wounds; and (c) represents the fluorescence intensity value of type III collagen in each group of E. coli-infected rabbit wounds. Figure 12 A schematic diagram comparing the newly formed microvessels in burn wound tissue; where (a) represents DAPI / CD31 immunofluorescence staining of wound tissue in each group; (b) represents the vascular density of each group of burn wounds in rabbits infected with MRSA; and (c) represents the vascular density of each group of burn wounds in rabbits infected with E. coli. Figure 13 This is a schematic diagram showing the ELISA test results of tissues in different groups after treatment of burn wounds infected with MRSA; where (a) represents the TNF-α level in wound tissues of each group; (b) represents the IL-6 level in wound tissues of each group; (c) represents the bFGF level in wound tissues of each group; and (d) represents the TGF-β1 level in wound tissues of each group. Figure 14 A schematic diagram showing the ELISA results of tissues in each group after treatment of burn wounds infected with E. coli; where (a) represents the TNF-α level in the wound tissues of each group; (b) represents the IL-6 level in the wound tissues of each group; (c) represents the bFGF level in the wound tissues of each group; and (d) represents the TGF-β1 level in the wound tissues of each group. Figure 15 This is a schematic diagram of the results of peripheral blood leukocyte and granulocyte counts; where (a) represents the leukocyte count in the peripheral blood of rabbits infected with MRSA; (b) represents the granulocyte count in the peripheral blood of rabbits infected with MRSA; (c) represents the leukocyte count in the peripheral blood of rabbits infected with E. colil; and (d) represents the granulocyte count in the peripheral blood of rabbits infected with E. colil. Detailed Implementation

[0044] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0045] Unless otherwise specified, all raw materials used in the embodiments of this invention are commercially available products.

[0046] Example 1: Preparation of antioxidant hydrogel Step 1. Construct a porous polyporphyrin host using a covalent organic framework (COF). Two-dimensional planar conjugated polypor-COF was constructed using TAPP and TFPP as building blocks via a solvothermal method: equimolar amounts of 5,10,15,20-tetra(4-aminophenyl)porphyrin (TAPP) and 5,10,15,20-tetra(4-aldehydephenyl)porphyrin (TFPP) were dissolved in a mixed solvent of dichlorobenzene and n-butanol. After ultrasonic dispersion for 5 min, the mixture was reacted in a sealed environment at 120 °C for 72 h. Subsequently, the mixture was thoroughly washed with DMF, THF, and acetone, and then vacuum dried at 60 °C for 24 h to obtain polypor-COF.

[0047] Step 2. Introduce Os for metal coordination to form polypor(Os). 10 mg of polypor was dispersed in 10 mL of DMF, followed by the addition of 0.05 mM osmium chloride. The mixture was sonicated for 10 min to disperse evenly, and then stirred continuously at 120 °C for 12 h. After filtration, the mixture was washed three times in sequence with DMF, deionized water, and ethanol, and then dried at 60 °C for 24 h to obtain metal-doped polypor (Os).

[0048] Step 3. Synergistically integrate the natural antioxidant alpha-lipoic acid (LA) to construct an antioxidant sonodynamic hydrogel. Weigh 1.03g of α-lipoic acid (LA), dissolve it in 5mL of pure water, add 0.2g of sodium bicarbonate (NaHCO3) at 45℃ and mix thoroughly. Then add different concentrations of polypor(Os) and stir vigorously at 60℃ for 3h to form an antioxidant hydrogel polypor(Os)@PLA with sonodynamic ROS production ability.

[0049] Effect verification The efficacy of ultrasound-assisted polypor(Os)@PLA hydrogel in treating infected burn wounds in rabbits was verified in vitro and in vivo. A schematic diagram of the in vitro and in vivo experiments of ultrasound-assisted polypor(M)@PLA in treating infected burn wounds is shown below. Figure 1 As shown.

[0050] Highly effective antibacterial effect in the early stages of infection, such as Figures 2-4 As shown in the figure, in in vitro models of MRSA and E. coli, and in a New Zealand rabbit second-degree burn infection model, polypor(Os)@PLA hydrogel, under the synergistic effect of ultrasound, achieved a bactericidal rate of >95% as indicated by OD600, plate count, live / dead staining, and SEM observation. The polypor(Os) sonosensitive agent simulates POD enzyme activity to generate ROS in an acidic wound environment, while the sonodynamic effect significantly enhances local ROS generation. The porous structure of the PLA hydrogel facilitates bacterial contact, and the mechanical disturbance of ultrasound accelerates the local diffusion range of ROS, allowing the bactericidal effect to penetrate deeper into the infected area rather than just the surface, thereby rapidly inhibiting the proliferation of drug-resistant bacteria and reducing the risk of infection spread.

[0051] The antioxidant and repair-promoting effects in the later stages of infection are as follows Figures 5-9 As shown in the figure. DPPH and SOD tests, as well as cellular-level ROS fluorescence staining, indicate that after early sterilization under ultrasonic stimulation, polypor(Os)@PLA can continuously neutralize residual ROS, effectively reducing oxidative stress. In vivo DHE staining also confirmed that in wound tissue, the ROS level in the polypor(Os)@PLA+US group returned to near normal tissue levels, while the control group and antibiotic group remained in a high-oxidation state. The lipoic acid in PLA hydrogel not only provides mechanical support and a moist microenvironment, but also dynamically regulates the local free radical concentration in the wound through stable release, reducing oxidative stress damage to mitochondria, proteins, and DNA, protecting proliferating fibroblasts and endothelial cells, and avoiding secondary necrosis caused by excessive inflammation, thereby significantly optimizing repair conditions.

[0052] The ability to promote angiogenesis and collagen deposition is as follows: Figures 10-12 As shown in the figure. Masson staining, CD31 immunofluorescence, and type III collagen fluorescence experiments all showed that the angiogenesis density and collagen ratio in the polypor(Os)@PLA+US group were significantly increased, especially the expression of type III collagen during the proliferative phase, which was significantly better than that in the antibiotic group. After early ROS clearance controlled the infection and stabilized the microenvironment, the mechanical effect of ultrasound could stimulate local microcirculation, further activate vascular endothelial cell function, and promote CD31 expression; while the increase in type III collagen provided support for the stable remodeling of the extracellular matrix, indicating that this hydrogel has good regulatory ability in the early and middle stages of tissue regeneration, and is not just a simple bactericidal material.

[0053] The effects of inflammation control and immune microenvironment optimization are as follows: Figures 13-15As shown in the figure, in animal experiments, the TNF-α level in the polypor(Os)@PLA+US group was significantly decreased, and the white blood cell and granulocyte counts tended to normalize, while the antibiotic group still had a high level of inflammation. In the early stage, the hydrogel controls the source of infection through ROS-mediated sterilization; in the middle stage, lipoic acid regulates the inflammatory response through antioxidant action, reduces the level of excessive pro-inflammatory factors, avoids the continuous activation of macrophages and neutrophils, and alleviates tissue damage; the improved microcirculation and mechanical stimulation under ultrasound can also assist in the migration and clearance of inflammatory cells, thereby reshaping a favorable immune microenvironment in the wound as a whole.

[0054] In the description of embodiments of the present invention, the terms "first," "second," "third," and "fourth" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first," "second," "third," or "fourth" may explicitly or implicitly include one or more of that feature. In the description of the present invention, unless otherwise stated, "a plurality of" means two or more.

[0055] In the description of the embodiments of the present invention, it should be understood that "-" and "~" represent a range of two numerical values, and this range includes the endpoints. For example, "AB" represents a range greater than or equal to A and less than or equal to B. "A~B" represents a range greater than or equal to A and less than or equal to B.

[0056] In the description of embodiments of the present invention, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0057] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for preparing an antioxidant sonodynamic hydrogel, characterized in that, The method comprises the following steps: Preparation of a sound-sensitive organic framework material; Mixing a metal salt with the sound-sensitive organic framework material in a first solvent, ultrasonic treatment, heating, drying, and preparation of a metal-doped organic framework material; Mixing a base with an antioxidant containing a disulfide bond or a mercapto group in a second solvent, activation of the disulfide bond or the mercapto group, and then mixing with the metal-doped organic framework material to perform a cross-linking reaction and coordination, and preparation of the antioxidant sonodynamic hydrogel; The sound-sensitive organic framework is selected from a porphyrin-based covalent organic framework, a metal porphyrin framework, a phthalocyanine-based coordination polymer, a metal phthalocyanine MOF, a porous silicon-loaded porphyrin ultrasound-responsive material, or a graphene oxide-loaded porphyrin ultrasound-responsive material. The metal in the metal salt includes osmium.

2. The method of claim 1, wherein the antioxidant sonodynamic hydrogel is prepared by the steps of: The metal in the metal salt further includes one or more of ruthenium, iron, rhodium, iridium, and chromium.

3. The method for preparing the antioxidant sonodynamic hydrogel as described in claim 1, characterized in that, The metal salt is osmium chloride.

4. The method for preparing the antioxidant sonodynamic hydrogel as described in claim 1, characterized in that, The sound-sensitive organic framework is a porphyrin-based covalent organic framework, which is prepared by a solvothermal method from raw materials containing a first organic ligand and a second organic ligand. The first organic ligand is 5,10,15,20-tetrakis(4-aminophenyl)porphyrin, and / or the second organic ligand is 5,10,15,20-tetrakis(4-formylphenyl)porphyrin.

5. The method of claim 4, wherein the antioxidant sonodynamic hydrogel is prepared by the steps of: The solvothermal method satisfies one or more of the following conditions: (1) The molar ratio of the first organic ligand to the second organic ligand is 1:(0.5-1.5); (2) The solvothermal method is performed in an organic solvent selected from one or more of dichlorobenzene and n-butanol; (3) The solvothermal method is performed at a temperature of 100-140°C.

6. The method of claim 1, wherein the antioxidant sonodynamic hydrogel is prepared by the steps of: The antioxidant is selected from thioctic acid.

7. The method of preparing the antioxidant sonodynamic hydrogel according to any one of claims 1 to 6, wherein, The preparation method satisfies one or more of the following conditions: (1) The first solvent is selected from DMF; (2) The second solvent is selected from water; (3) The base is sodium bicarbonate; (4) The heating temperature is 100-140°C.

8. The method of preparing the antioxidant sonodynamic hydrogel according to any one of claims 1 to 6, wherein, The activation of the disulfide bond or the mercapto group is performed at a temperature of 40-50°C; and / or the cross-linking reaction and coordination are performed at a temperature of 55-65°C.

9. The antioxidant sonodynamic hydrogel prepared by the preparation method of any one of claims 1-8.

10. Use of the antioxidant sonodynamic hydrogel of claim 9 in the preparation of a material for treating burn infectious wounds.

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