title: Cerium oxide nanoparticle aggregates affect stress response and function in Caenorhabditis elegans.
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 (CeO2) 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 CeO2 nanoparticles affects indices of whole animal stress and survivability in Caenorhabditis elegans.
  
  
  METHODS
  Caenorhabditis elegans were exposed to different concentrations of CeO2 nanoparticles and evaluated.
  
  
  RESULTS
  Our findings demonstrate that chronic exposure of CeO2 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, CeO2 aggregates promoted strain-dependent decreases in animal fertility, a decline in stress resistance as measured by thermotolerance, and shortened worm length.
  
  
  CONCLUSIONS
  The data obtained from this study reveal the sublethal toxic effects of CeO2 nanoparticle aggregates in Caenorhabditis elegans and contribute to our understanding of how exposure to CeO2 may affect the environment.
authors.affiliation: Center for Diagnostic Nanosystems, Marshall University, Huntington, WV, USA.
authors.forename: Steven
authors.initials: S
authors.lastname: Rogers
authors.affiliation: Center for Diagnostic Nanosystems, Marshall University, Huntington, WV, USA.
authors.forename: Kevin M
authors.initials: KM
authors.lastname: Rice
authors.affiliation: Center for Diagnostic Nanosystems, Marshall University, Huntington, WV, USA.
authors.forename: Nandini Dpk
authors.initials: ND
authors.lastname: Manne
authors.affiliation: Department of Mechanical Engineering and Engineering Mechanics, Michigan Technological University, Houghton, MI, USA.
authors.forename: Tolou
authors.initials: T
authors.lastname: Shokuhfar
authors.affiliation: Department of Mechanical Engineering and Engineering Mechanics, Michigan Technological University, Houghton, MI, USA; School of Material Science and Engineering, Shandong University, Jinan, China.
authors.forename: Kun
authors.initials: K
authors.lastname: He
authors.affiliation: Center for Diagnostic Nanosystems, Marshall University, Huntington, WV, USA.
authors.forename: Vellaisamy
authors.initials: V
authors.lastname: Selvaraj
authors.affiliation: Center for Diagnostic Nanosystems, Marshall University, Huntington, WV, USA; Department of Pharmaceutical Sciences and Research, Marshall University, Huntington, WV, USA.
authors.forename: Eric R
authors.initials: ER
authors.lastname: Blough
keywords: Caenorhabditis elegans; Cerium oxide nanoparticles; nanoparticles; stress response; toxicity