Effects of Nanoceria on Human Platelet Functions and Blood Coagulation.

PURPOSE: Cerium oxide nanoparticles (nanoceria) exist in either 3+ or 4+ oxidation state with interesting redox properties and exhibit both oxidant and antioxidant attributes based on concentration, environment and pH. Thanks to their wide spread use in fuel, cosmetics and other industries as well as in biomedical field, nanoceria particles get released into environment with risk of significant human exposure, and thus necessitate careful examination and optimization of their biomedical applications. METHODS: This research was planned to explore effects of nanoceria on human platelet functions and whole blood coagulation. Platelets and whole blood from volunteer healthy donors were treated with different doses of nanoceria and various platelet functions, fibrin polymerization and blood coagulation were tested. RESULTS: Nanoceria particles were found to reduce platelet aggregation and secretion of granule contents in a dose-dependent manner, impaired fibrin polymerization and retraction of fibrin-rich thrombi, associated with reduced cytosolic filamentous actin. Remarkably, nanoceria instigated early clot formation in whole blood attributable to putative activation of coagulation cascade. CONCLUSION: Above observations provide cautionary framework to critically re-evaluate and accordingly plan biomedical applications of nanoceria.