A Mxene@TA/Fe dual-nanozyme composited antifouling hydrogel for burn wound repair

Bacterial infection, oxidative stress, and inflammation response severely hinder burn wound repair. To address these issues, a multifunctional quaternary ammonium modified chitosan-sulfonic betaine acrylamide hydrogel loaded with Mxene@TA/Fe nanosheets was developed for burn wound healing. Since zwitterionic sulfonate betaine acrylamide exhibited good antifouling properties, thus the hydrogel system resisted protein adsorption and bacterial adhesion and avoided wound infection. Moreover, Mxene@TA/Fe nanosheets simultaneously showed catalase (CAT)-like and peroxidase (POD)-like activities because the high conductivity of Mxene augmented the electron transfer rate and promoted the transformation of Fe(Ⅱ) to Fe(Ⅲ) and vice-versa. The POD-like activity combined with photothermal therapy led to a highly effective antibacterial capacity, while the CAT-like activity produced oxygen and alleviated tissue hypoxia. Furthermore, MXene@TA/Fe nanosheets showed a good antioxidant capacity because MXene and TA molecules scavenged toxic reactive oxygen species and reduced oxidative stress. In vivo experiment further proved that the prepared hydrogel could significantly promote burn wound healing by facilitating granulation tissue regeneration, epithelial layer formation, and collagen deposition.