Preclinical studies conducted on nanozyme antioxidants: shortcomings and challenges based on US FDA regulations

The wide prevalence of oxidative stress-induced diseases has led to a growing demand for antioxidant therapeutics worldwide. Nanozyme antioxidants are drawing enormous attention as practical alternatives for conventional antioxidants. The considerable body of research over the last decade and the promising results achieved signify the potential of nanozyme antioxidants to secure a place in the expanding market of antioxidant therapeutics. Nonetheless, there is no report on clinical trials for their further evaluation. Through analyzing in-depth selected papers which have conducted in vivo studies on nanozyme antioxidants, this review aims to pinpoint and discuss possible reasons impeding development of research toward clinical studies and to offer some practical solutions for future studies to bridge the gap between preclinical and clinical stages.