Photothermal antibacterial MoS₂ composited chitosan hydrogel for infectious wound healing

Pathological bacterial infection poses a serious threat to public health security. The excessive use of antibiotics has resulted in a serious decline in treatment effect and bacterial resistance. For the treatment of infected wounds, we compounded dopamine-assisted exfoliated molybdenum disulfide (MoS₂@PDA) into lipoic acid modified chitosan (LAMC) to obtain a composite hydrogel dressing (LAMC-MoS₂@PDA). LAMC-MoS₂@PDA hydrogels exhibited excellent photothermal conversion ability and the LAMC-MoS₂@PDA2 group (0.3 wt%) has a photothermal conversion efficiency of 26.29 %. Meanwhile, they showed good biocompatibility and ROS scavenging activity in vitro. Photothermal therapy usually utilizes photothermal agents to convert near-infrared light into heat energy for bacterial cell membrane destruction and bacterial protein inactivation. Under the near-infrared light irradiation, the antibacterial ratio of LAMC-MoS₂@PDA hydrogels against Staphylococcus aureus and Escherichia coli reached nearly 100 %, and the morphology of the bacteria showed obvious contraction and cleavage. The hydrogels also showed an excellent antibacterial effect and wound healing promotion in the infected wound of rats. In particular, the LAMC-MoS₂@PDA2 (+) group (with NIR) showed almost complete wound closure after 14 days, indicating that the LAMC-MoS₂@PDA hydrogels have great potential in clinical anti-infected treatment.