Redox Trimetallic Nanozyme with Neutral Environment Preference for Brain Injury.

Metal nanozyme has attracted wide interest for biomedicine, and a highly catalytic material in physiological environment is highly desired. However, catalytic selectivity of nanozyme is still highly challenged, limiting its wide application. Here, we show a trimetallic (triM) nanozyme with highly catalytic activity and environmental selectivity. Enzyme-mimicked investigations find that triM system possesses multienzyme mimetics activity for removing reactive oxygen species (ROS) and reactive nitrogen species (RNS), such as 1O2, H2O2, •OH, and •NO. Importantly, triM nanozyme exhibits the significant neutral environment preference for removing •OH, 1O2, and •NO free radical, indicating its highly catalytic selectivity. The Density Functional Theory (DFT) calculations reveal triM nanozyme can capture electrons very easily and provide more attraction to reactive oxygen and nitrogen species (RONS) radicals in neutral environment. In vitro experiments show triM nanozyme can improve the viability of injured neural cell. In LPS-induced brain injury model, the superoxide dismutase (SOD) activity and lipid peroxidation can be greatly recovered after triM nanozyme treatment. Moreover, the triM nanozyme treatment can significantly improve the survival rate, neuroinflammation and reference memory of injured mice. Present work provides a feasible route for improving selectivity of nanozyme in physiological environment as well as exploring potential applications in brain science.