Cellular and Molecular Toxicology of Nanoparticles

Tiago Alves Jorge de Souza, Thiago Lopes Rocha, Leonardo Pereira Franchi

This chapter will present an original effort to summarize the relevant data about the cyto-genotoxicity induced by cerium dioxide nanoparticles (nanoceria) in physiologically (in vivo and in vitro) relevant models. In this way, this chapter should be extremely useful to everyone who wants to plan their research and publishing their results. Massive application of nanoceria at different fields is increasing year after year, and it is urgent to address and discuss their use and its safety-related issues. Specifically, the nanoceria are being designed for nanomedicine, cosmetics, polishing materials and additives for automotive fuels. Their unique properties include the ability to absorb UV radiation, antioxidant potential and the rapid exchange of valence between Ce4+and Ce3+ions associated to oxygen storage. In this chapter, the state of the art regarding the physicochemical properties of nanoceria, nanogenotoxicity detected by in vitro and in vivo systems and the general aspects in the cyto-genotoxic mechanism of nanoceria are summarized. The cyto-genotoxicity will be discussed in terms of evaluations by Comet assay, Micronucleus test, DNA damage response and oxidative stress detected in cell culture systems and in vivo test. We also described the dose dependent cyto-genotoxic effects of nanoceria based on their physical-chemical nature. Paradoxically, these particles have been characterized as either pro-oxidant or anti-oxidant in dependence of microenvironment and physiological conditions such as pH. Finally, this chapter will contribute to point out aspects of the development of new in vitro and in vivo methodologies to detect cyto-genotoxic effects of the nanoceria.