Abstract
We have synthesized ceria nanoparticles by reacting cerium salts and sodium hydroxide without any additive in order to avoid possible cytotoxicity. The synthesized ceria nanoparticles were with cubic structure according to X-ray diffraction and have diameters between 6 and 10 nm analyzed by transmission electron microscopy. Aggregation behaviors of ceria nanoparticles in DI water and cell culture media have been studied by dynamic light scattering. In de-ionized water, ceria nanoparticles formed a stable colloidal solution with hydrodynamic size ~ 70 nm and zeta potential ~ 47 mV. Dispersion of the nanoparticles in serum-free media was found to result in larger aggregates, while the nanoparticles in serumcontaining media form a stable solution, which suggests that proteins in serum and ceria nanoparticles have some interactions. In cellular uptake test, entry of ceria nanoparticles into HeLa cells incubated in serum-containing media at 37 °C for 60 min was observed and without cytotoxicity. © 2013 SPIE.