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

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