Cerium oxide nanoparticle: a remarkably versatile rare earth nanomaterial for biological applications

Cerium oxide nanoparticles have the unique power to act as both oxidation and reduction catalysts, thanks to the ability of cerium to rapidly switch between two oxidation states. Can Xu and Xiaogang Qu from the Chinese Academy of Sciences review how this dual catalytic activity yields enzyme-like behavior that can be harnessed for cancer-detecting assays and new biomedical applications. The nanoparticles mimic enzyme species, such as superoxide dismutases and catalases, that repair the damage caused by free radicals and reduce harmful reactive oxygen levels in the body. With tiny dimensions that allow them to enter cellular spaces inaccessible to traditional medicines - including crossing the blood-brain barrier for Alzheimer's disease treatments - these nanomaterials may offer potent remedies against degenerative diseases. Xu and Qu stress the need for systematic biological testing, however, to resolve possible toxicity concerns.