Cerium Oxide-Based Nanozymes in Biology and Medicine

Abstract

Biological enzymes are excellent biocatalysts because they display high specificity to their substrates and accelerate the rate of biochemical reactions to many folds. Despite these and several other advantages, the catalytic performances of natural enzymes are found to be compromised when exposed to heavy metals-based inhibitors and different conditions of their optimum temperature and pH. The high cost of synthesis, isolation, and purification are some of the typical constraints over their broad-spectrum utility. However, nanoparticle-based biological enzyme mimetic is currently growing exponentially with particular interest to the biological applications. Although there are several types of nanomaterials discovered for displaying various biological enzyme-like activities, this chapter comprehensively covers the cerium oxide nanoparticles (nanoceria)-based enzyme mimetic systems and related biological applications. Recently, nanoceria has been explored for possessing the superoxide dismutase, catalase, peroxidase, and oxidase enzyme-like activities. Nanoceria has reported to exhibit antioxidant (ability to inhibit oxidative stress) as well as prooxidant (ability to generate reactive oxygen species) activities. These enzyme mimetic activities can be tuned by modulating the synthesis process and surface modification of nanoceria.