Ultrasmall gold decorated bimetallic metal-organic framework based nanoprobes for enhanced chemodynamic therapy with triple amplification.

Chemodynamic therapy (CDT) has shown potential for important applications in tumor precision therapy, but insufficient endogenous hydrogen peroxide (HO), overexpressed glutathione (GSH) and a weak Fenton-reaction rate greatly reduced the efficacy of CDT. Herein, a metal-organic framework (MOF) based bimetallic nanoprobe with self-supplying HO was developed for enhancing CDT with triple amplification, in which ultrasmall gold nanoparticles (AuNPs) were deposited on Co-based MOFs (ZIF-67), and manganese dioxide (MnO) nanoshells were coated to form a ZIF-67@AuNPs@MnO nanoprobe. In the tumor microenvironment, MnO depleted overexpressed GSH to produce Mn, and the bimetallic Co/Mn nanoprobe accelerated the Fenton-like reaction rate. Moreover, by catalyzing glucose ultrasmall AuNPs, the self-supplying HO further promoted hydroxyl radical (˙OH) generation. Compared with those of ZIF-67 and ZIF-67@AuNPs, the ˙OH yield of ZIF-67@AuNPs@MnO obviously increased, due to which the cell viability decreased to 9.3%, and the tumor completely disappeared, indicating the enhanced CDT performance of the ZIF-67@AuNPs@MnO nanoprobe.