title: Ce³+ ions determine redox-dependent anti-apoptotic effect of cerium oxide nanoparticles.
abstract: Antioxidant therapy is the novel frontier to prevent and treat an impressive series of severe human diseases, and the search for adequate antioxidant drugs is fervent. Cerium oxide nanoparticles (nanoceria) are redox-active owing to the coexistence of Ce(3+) and Ce(4+) oxidation states and to the fact that Ce(3+) defects, and the compensating oxygen vacancies, are more abundant at the surface. Nanoceria particles exert outstanding antioxidant effects in vivo acting as well-tolerated anti-age and anti-inflammatory agents, potentially being innovative therapeutic tools. However, the biological antioxidant mechanisms are still unclear. Here, the analysis on two leukocyte cell lines undergoing apoptosis via redox-dependent or independent mechanisms revealed that the intracellular antioxidant effect is the direct cause of the anti-apoptotic and prosurvival effects of nanoceria. Doping with increasing concentrations of Sm(3+), which progressively decreased Ce(3+) without affecting oxygen vacancies, blunted these effects, demonstrating that Ce(3+)/Ce(4+) redox reactions are responsible for the outstanding biological properties of nanoceria.
authors: Department of Biology, University of Roma "Tor Vergata", Rome, Italy.
authors: Ivana
authors: I
authors: Celardo
authors: Milena
authors: M
authors: De Nicola
authors: Corrado
authors: C
authors: Mandoli
authors: Jens Z
authors: JZ
authors: Pedersen
authors: Enrico
authors: E
authors: Traversa
authors: Lina
authors: L
authors: Ghibelli