Cerium oxide nanoparticle aggregates affect stress response and function in

Abstract

Objective: The continual increase in production and disposal of nanomaterials raises concerns regarding the safety of nanoparticles on the environmental and human health. Recent studies suggest that cerium oxide (CeO 2 ) nanoparticles may possess both harmful and beneficial effects on biological processes. The primary objective of this study is to evaluate how exposure to different concentrations (0.17–17.21 µg/mL) of aggregated CeO 2 nanoparticles affects indices of whole animal stress and survivability in Caenorhabditis elegans . Methods: Caenorhabditis elegans were exposed to different concentrations of CeO 2 nanoparticles and evaluated. Results: Our findings demonstrate that chronic exposure of CeO 2 nanoparticle aggregates is associated with increased levels of reactive oxygen species and heat shock stress response (HSP-4) in Caenorhabditis elegans , but not mortality. Conversely, CeO 2 aggregates promoted strain-dependent decreases in animal fertility, a decline in stress resistance as measured by thermotolerance, and shortened worm length. Conclusion: The data obtained from this study reveal the sublethal toxic effects of CeO 2 nanoparticle aggregates in Caenorhabditis elegans and contribute to our understanding of how exposure to CeO 2 may affect the environment.