Distribution, Elimination, and Biopersistence to 90 Days of a Systemically Introduced 30 nm Ceria-Engineered Nanomaterial in Rats

• DOI: 10.1093/toxsci/kfs067
• Publication Date: 2012-02-25T01:15:14Z
• Authors: Robert A. Yokel; Tu C. Au; Robert MacPhail; Sarita S. Hardas; D. Allan Butterfield; Rukhsana Sultana; Michael Goodman; Michael T. Tseng; Mo Dan; Hamed Haghnazar; Jason M. Unrine; Uschi M. Graham; Peng Wu; Eric A. Grulke
• Keywords: Mononuclear phagocyte system; Nanotoxicology

Nanoceria is used as a catalyst in diesel fuel, an abrasive printed circuit manufacture, and being pursued antioxidant therapeutic. Our objective to extend previous findings showing that there were no reductions of cerium organs the mononuclear phagocyte (reticuloendothelial) system up 30 days after single nanoscale ceria administration. An ~5% aqueous dispersion citrate-stabilized nm ceria, synthesized characterized in-house, or vehicle, was iv infused into rats terminated 1, 7, 30, 90 later. Cageside observations obtained daily, body weight weekly. Daily urinary fecal outputs quantified for 2 weeks. Nine weighed samples collected from 14 tissues/organs/systems, blood cerebrospinal fluid determination. Histology oxidative stress assessed. Less than 1% nanoceria excreted first weeks, 98% feces. Body gain initially impaired. Spleen significantly increased some ceria-treated groups, associated with abnormalities. Ceria primarily retained spleen, liver, bone marrow. There little decrease any tissue over days. Granulomas observed liver. Time-dependent changes seen liver spleen. Nanoscale persistently by system, adverse changes. The results support concern about long-term fate effects inert metal oxides distribute throughout body, are retained, produce