Multi-enzymatic activities of ultrasmall ruthenium oxide for anti-inflammation and neuroprotection

Artificial enzymes to mimic the endogenous antioxidant system are promising candidates for treating and manipulating the in vivo dysregulated redox homeostasis. Though progresses have been made for reactive oxygen species (ROS) scavenging using nanozymes, nanomaterials with advanced multi-enzymatic activities and enhanced biocompatibility have been rarely explored. Herein, we report the facile construction of RuO₂-PVP nanoparticles, as a single-component, multi-enzyme-mimicking nano-platform for multi-ROS scavenging, which simultaneously shows multi-enzymatic antioxidant activities mimicking intrinsic catalase, superoxide dismutase, peroxidase, as well as ascorbate peroxidase and thiol peroxidase. Owing to the multifunctional self-synergistic inhibitions on multi-ROS, e.g., H₂O₂, ·OH and O₂^·−, the fabricated RuO₂-PVP nanozymes demonstrate a prominent redox homeostasis protection effect, which not only protects lipid, DNA and protein from damages by UV/H₂O₂/Fenton stimulation in vitro, but also performs magnificent ROS elimination properties against inflammation and Parkinson's disease in vivo. The constructed RuO₂-based nanozymes provide a potential therapeutic nano-platform for the treatment of oxidative stress-related diseases.