title: In Vivo Processing of Ceria Nanoparticles inside Liver: Impact on Free-Radical Scavenging Activity and Oxidative Stress.
abstract: The cytotoxicity of ceria ultimately lies in its electronic structure, which is defined by the crystal structure, composition, and size. Despite previous studies focused on ceria uptake, distribution, biopersistance, and cellular effects, little is known about its chemical and structural stability and solubility once sequestered inside the liver. Mechanisms will be presented that elucidate the in vivo transformation in the liver. In vivo processed ceria reveals a particle-size effect towards the formation of ultrafines, which represent a second generation of ceria. A measurable change in the valence reduction of the second-generation ceria can be linked to an increased free-radical scavenging potential. The in vivo processing of the ceria nanoparticles in the liver occurs in temporal relation to the brain cellular and protein clearance responses that stem from the ceria uptake. This information is critical to establish a possible link between cellular processes and the observed in vivo transformation of ceria. The temporal linkage between the reversal of the pro-oxidant effect (brain) and ceria transformation (liver) suggests a cause-effect relationship.
authors: Center for Applied Energy Research and Catalysis Research and Testing Center, University of Kentucky, 2540 Research Park Drive, Lexington, KY 40511 (USA).
authors: Uschi M
authors: UM
authors: Graham
authors: Department of Anatomical Sciences and Neurobiology, University of Louisville, Louisville, KY 40204 (USA).
authors: Michael T
authors: MT
authors: Tseng
authors: Conn Center for Renewable Energy, University of Louisville, Louisville, KY 40204 (USA).
authors: Jacek B
authors: JB
authors: Jasinski
authors: Pharmaceutical Sciences and Graduate Center for Toxicology, University of Kentucky, Lexington, KY 40506 (USA).
authors: Robert A
authors: RA
authors: Yokel
authors: Department of Plant and Soil Sciences, University of Kentucky, Lexington, KY 40506 (USA).
authors: Jason M
authors: JM
authors: Unrine
authors: Center for Applied Energy Research and Catalysis Research and Testing Center, University of Kentucky, 2540 Research Park Drive, Lexington, KY 40511 (USA).
authors: Burtron H
authors: BH
authors: Davis
authors: National Institute of Occupational Safety and Health (NIOSH), Cincinnati, OH 45226 (USA).
authors: Alan K
authors: AK
authors: Dozier
authors: Department of Chemistry, University of Kentucky, Lexington, KY 40506 (USA).
authors: Sarita S
authors: SS
authors: Hardas
authors: Department of Chemistry, University of Kentucky, Lexington, KY 40506 (USA).
authors: Rukhsana
authors: R
authors: Sultana
authors: Chemical and Materials Engineering Department, University of Kentucky, Lexington, KY 40506 (USA).
authors: Eric A
authors: EA
authors: Grulke
authors: Department of Chemistry, University of Kentucky, Lexington, KY 40506 (USA).
authors: D Allan
authors: DA
authors: Butterfield
keywords: biotransformations; cellular chemistry; cerium; nanoparticles; redox chemistry