PEGylated nanoceria protect human epidermal cells from reactive oxygen species

Background Cerium oxide nanoparticles (CeNPs) have shown promise as catalytic antioxidants in cell culture and animal models due to its superoxide dismutase and catalase mimetic activities. CeNPs can exist in +3 and +4 oxidation states, which have been suggested as the mechanism behind the free radical scavenging activity. It has also been shown that unique crystal structure of CeNPs with surface oxygen defects promote the shuffling between the +3 and +4 oxidation states that help in eliminating the free radicals. This activity of CeNPs has been suggested as the mechanism, at least in part, behind increase in cellular longevity and decrease in the toxic insults in mammalian cells/tissues. Further, the uniform distribution of CeNPs, upon cellular uptake, within the cells could prevent the accumulation of reactive oxygen species in the cells.