Synthesis Of Antibacterial Hydrogels Based On Dopamine-modified Hyaluronic Acid And Their Wound Therapy

As the largest and most important protective organ of the human body,the skin tissue is extremely susceptible to external damage and infection by pathogenic bacteria,which may even threaten the life and health of patients in severe cases.Therefore,there is an urgent need to develop wound dressings that prevent bacterial infection.Hydrogels are a class of polymers with high water content with a three-dimensional porous network structure,which have excellent properties such as simulating the microenvironment of human tissue,absorbing wound exudate and providing a long-term moist healing environment,making the hydrogel stand out among many wound dressings.However,traditional hydrogels suffer from poor antibacterial activity,insufficient mechanical strength,and uncontrollable defects in practical applications,which limit their application in the biomedical field.In view of the above problems,this topic explores the use of dopamine-modified hyaluronic acid as the hydrogel skeleton,and through modification to obtain a hydrogel wound dressing with excellent antibacterial activity and adjustable mechanical properties,the specific research contents are as follows:（1）In this work,in view of the poor antibacterial activity of hydrogels,a multimodal synergistic antibacterial hydrogel based on dopamine-modified oxidized hyaluronic acid was developed,and its in vitro antibacterial activity and biocompatibility were demonstrated.First,dopamine-modified oxidized hyaluronic acid（OHA-DA）was used as the hydrogel backbone.A dual-dynamically cross-linked injectable hydrogel was constructed by mixing OHA-DA,Fe³⁺with cationic antimicrobial peptide polylysine（EPL）via Schiff base and coordination complexation.Next,glucose oxidase-loaded MoS₂ nanosheets were synthesized through electrostatic interaction and loaded into the hydrogel through physical mixing,and finally a multimodal synergistic antibacterial hydrogel OD/EPL/GM was obtained.Antibacterial experiments show that the hydrogel has good antibacterial activity against E.coli and S.aureus,and the antibacterial rate can reach 99.99%.（2）In view of the poor and uncontrollable mechanical properties of injectable hydrogels,we developed an injectable hydrogel with phototunable mechanical properties.First,dopamine-modified hyaluronic acid（HA-DA）was obtained by amidation reaction.The metal-organic framework PCN-224 was synthesized by a hydrothermal method,and PCN-224 was loaded onto black phosphorus nanosheets to prepare PCN@BP.Next,an injectable hydrogels HA-DA/Fe³⁺/PCN@BP was prepared by complexation.The PCN@BP in the hydrogel can generate reactive oxygen species to oxidize DA polymerization under 660 nm laser irradiation,thereby introducing chemical crosslinking into the hydrogel in situ and effectively improving the mechanical properties of the hydrogel.（3）using E.coli and S.aureus as experimental indicator bacteriato to interact with injectable hydrogel HA-DA/Fe³⁺/PCN@BP,the efficient bactericidal effect was confirmed by plate counting method,live/dead bacterial staining and scanning electron microscopy（SEM）.In addition,the good biocompatibility of the HA-DA/Fe³⁺/PCN@BP hydrogel was confirmed by cell viability assay,cell migration assay and hemolysis assay.Based on the above results,a mouse wound infection model was finally constructed to evaluate the in vivo antibacterial and wound healing properties of the hydrogel.The results showed that the hydrogel could effectively eliminate bacterial infection and accelerate wound healing in mice.