Vanadium Oxide Nanozymes with Multiple Enzyme-Mimic Activities for Tumor Catalytic Therapy

Using tumors containing high concentrations of hydrogen peroxide to design nanozymes is a new and effective strategy, and vanadium-based nanomaterials receive increasing attention. In this paper, four kinds of vanadium oxide nanozymes with different valences of vanadium are synthesized by a simple method to verify the effect of valence on enzyme activity. Vanadium oxide nanozyme-III (Vnps-III) with a low valence of vanadium (V4+) exhibits good peroxidase (POD) and oxidase (OXD) activities, which can effectively produce reactive oxygen species (ROS) in the tumor microenvironment for tumor treatment. In addition, Vnps-III can also consume glutathione (GSH) to reduce ROS consumption. Vanadium oxide nanozyme-I (Vnps-I) containing a high valence of vanadium (V5+) has catalase (CAT) activity, which can catalyze hydrogen peroxide (H2O2) into oxygen (O2), which is beneficial to alleviate the hypoxic environment of solid tumors. Finally, a vanadium oxide nanozyme with both trienzyme simulation activity and GSH consumption ability was screened out by adjusting the ratio of V4+ to V5+ in vanadium oxide nanozymes. In cell and animal experiments, we successfully demonstrate that vanadium oxide nanozymes have excellent antitumor ability and high safety, which may bring great potential for clinical cancer treatment.