Magnetically retained and glucose-fueled hydroxyl radical nanogenerators for H2O2-self-supplying chemodynamic therapy of wound infections

Chemodynamic therapy (CDT) involving the highly toxic hydroxyl radical ((OH)-O-center dot) has exhibited tremendous potentiality in combating bacterial infection. However, its antibacterial efficacy is still unsatisfactory due to the insufficient H2O2 levels and near neutral pH at infection site. Herein, a glucose-fueled and H2O2-self-supplying (OH)-O-center dot nanogenerator (pFe(3)O(4)@GOx) based on cascade catalytic reactions is developed by immobilizing glucose oxidase (GOx) on the surface of PAA-coated Fe3O4 (pFe(3)O(4)). Magnetic pFe(3)O(4) can act as a horseradish peroxidase-like nanozyme, catalyzing the decomposition of H2O2 into (OH)-O-center dot under acidic conditions for CDT. The immobilized GOx can continuously convert non-toxic glucose into gluconic acid and H2O2, and the former improves the catalytic activity of pFe(3)O(4) nanozymes by decreasing pH value. The self-supplying H2O2 molecules effectively enhance the (OH)-O-center dot generation, resulting in the high antibacterial efficacy. In vitro studies demonstrate that the pFe(3)O(4)@GOx conducts well in reducing pH value and improving H2O2 level for self-enhanced CDT. Moreover, the cascade catalytic reaction of pFe(3)O(4) and GOx effectively avoids strong toxicity caused by directly adding high concentrations of H2O2 for CDT. It is worth mentioning that the pFe(3)O(4)@GOx performs highly efficient in vivo CDT of bacteria-infected wound via the localized long-term magnetic retention at infection site and causes minimal toxicity to normal tissues at therapeutic doses. Therefore, the developed glucose-fueled (OH)-O-center dot nanogenerators are a potential nano-antibacterial agent for the treatment of wound infections.