Right once for all: Zinc-modulated highly stable iron-based ROS generator under physiological conditions for promoting bacteria-infected wound healing

Iron-based metal–organic frameworks (Fe-MOFs) have been regarded as promising antibacterial alternatives towards antibiotics since they can generate strong reactive oxygen species (ROS) for combating bacterial-infected wounds. But its instability under physiological conditions could not only lead to attenuation of the catalytic activity but also result in a large accumulation of iron ions, which would increase the risk of additional wound infection due to the simultaneous role of iron as a nutrient for bacterial growth. Herein, zinc (Zn) doped Fe-MOFs (ZFMs), which was prepared via stabilizing the structure of Fe-MOFs (FMs) upon Zn doping to enhance the carboxyl group on the frameworks. It can maintain long-term stability in the physiological environment while FMs disintegrate rapidly within one minute. ZFMs inactivated drug-resistant Escherichia coli (E. coli) (1 × 106 CFU mL−1) with high efficiency (>98 %) and accelerated the E. coli infected wounds healed by up-regulating VEGFα factor, which was validated in vivo and vitro. In addition, fibroblast cells (L929) remained at 100 % cell viability after incubating with 150 μg mL−1 ZFMs for 48 h and presented negligible effects on the functions of important organs in animal experiments.