Enzyme-mimetic antioxidant nanomaterials for ROS scavenging: Design, classification, and biological applications

Reactive oxygen species (ROS) perform vital functions in numerous life processes and significantly affect physiological activities in different organ systems in the human body. However, excessive ROS accumulation is harmful and causes oxidative damage or ROS-related diseases. Recently, various natural enzyme-like nanomaterials with ROS-scavenging activities have been designed. These nanomaterials can be used as alternative substitutes for ideal antioxidants. This review summarizes various antioxidant nanomaterials in terms of their design, classification, and biological applications. First, different design strategies (e.g., modulating the size, shape, composition, ligand, or surface chemistry of nanomaterials or forming atomically distributed metal active centres) for regulating antioxidant activity are analysed. Second, various antioxidant nanomaterials based on the enzymatic properties and types of scavenged ROS are classified and summarized. Third, the representative biological applications of antioxidant enzyme-mimetic nanomaterials, including therapeutics, protective effects, and other ROS-related applications, are described. Finally, the challenges and perspectives regarding the use of these enzyme-like antioxidant nanomaterials are outlined. This review provides a deeper understanding of the design and biological application of antioxidant nanomaterials and offers guidance for improving biocatalytic performance and selecting future research directions.