Biological effects associated with nanoceria exposure

Cerium oxide nanoparticles (CeO2NPs, nanoceria) present two different oxidation states (Ce³⁺ and Ce⁴⁺) what can suppose an autoregenerativeredox cycle. Thus, nanoceria consistently exhibit both superoxide dismutase-mimetic activity, as well as catalase-mimeticactivity. According to that, potential applications of nanoceria to quenchreactive oxygen species (ROS) in biological systems are currently being investigated. In this context nanoceria can be a novel agent to protect cells and tissues against oxidative damage by its regenerative free radical scavenging properties. In fact, it use has been proposed against diseases related with increasing levels of reactive oxygen species, or even as an antitumoral agent. Nevertheless, alternative studies pointed out that moreattention needs to be paid to long-term approaches prior to an eventualapplication of nanoceria in biomedicine. This means that important controversy swirl over its use as a protective therapeutic agent andbiosafety concerns need to be solved before its biomedical applications.In this context the present review present the pros and the cons that theuse of nanoceria in nanomedicine can be posed.