Manganese-base Nanozyme Synergetic Photo-thermal Therapy For Bacterial Infection

The continuous emergence of multidrug-resistant(MDR)bacteria has greatly challenged the current antibiotic therapy due to the abuse of antibiotics.It is urgent to develop a new antibiotics-alternative antibacterial drug.Recently,nanozyme with low cost and high stability,meanwhile without drug resistance,has developed to a new generation of antibacterial agents.Herein,we prepare a manganese-doped dopamine-derived hollow carbon sphere(MnO_x/HNCS),as nanozyme and photo-thermal agent,further apply it in MDR bacteria-infected wound therapy.MnO_x/HNCS displays oxidase(OXD)-like and peroxidase(POD)-like activities,which can catalyze oxygen to generate superoxide anion by OXD-like activity,then in acidic condition,further converted to hydrogen peroxide,finally generated hydroxyl radical owing to the POD-like activity,to implement self-cascade enzyme catalysis.In addition,we also find that under near-infrared laser irradiation,the enzyme-like activities of MnO_x/HNCS significantly increase,due to that the manganese oxide-graphite carbon heterostructure can improve the electron transport rate.Furthermore,MnO_x/HNCS also has stable and excellent photo-thermal effect under near-infrared laser irradiation.Based on the synergistic effect of photo-thermal effect and photo-enhanced enzyme-like activities,MnO_x/HNCS combined with photo-therapy shows excellent bactericidal effect against MDR bacteria in vitro.In vivo experiments,it also has a good therapeutic effect on MDR bacteria-infected wound.It can promote wound healing by promoting the deposition of extracellular matrix and reepithelialization.In summary,this photo-responsive multifunctional therapeutic platform pave a new way for broad-spectrum and efficient antibacterial strategy.