Ceria-supported gold nanoparticles are prepared exhibiting peroxidase activity and acting as radical traps. Au/CeO2 shows a remarkable biocompatibility as demonstrated by measuring cellular viability, proliferation, and lack of apoptosis for two human cell lines (Hep3B and HeLa). The antioxidant activity of Au/CeO2 against reactive oxygen species (ROS) is demonstrated by studying the cellular behavior of Hep3B and HeLa in a model of cellular oxidative stress. It is determined that Au/CeO2 exhibits higher antioxidant activity than glutathione, the main cytosolic antioxidant compound, and its CeO2 carrier. Overall the result presented here shows the potential of implementing well-established nanoparticulated gold catalysts with remarkable biocompatibility in cellular biology. ; Martín González, R.; Alvaro Rodríguez, MM.; García Gómez, H.; Menchón, C.; Apostolova, N.; Victor, VM.; Herance Camacho, JR. (2012). Gold nanoparticles supported on nanoparticulate ceria as a powerful agent against intracellular oxidative stress. Small. 8(12):1895-1903. doi:10.1002/smll.201102255. ; Senia ; 1895 ; 1903 ; 8 ; 12