Detection of photoinduced formation of reactive oxygen species by aqueous TiO2 nanoparticles suspension in 3T3 cells

M. Kwak, M.B. Heo, V. Reipa, T.G. Lee
Korea Research Institute of Standards and Science,

Keywords: photocatalytic activity, nanotoxicology, engineered nanomaterials


As the use of nanomaterials in industrial and cosmetic processes increases, the nanosafety aspect becomes more and more emphasized in these days. It is prerequisite to assess the potential hazard of those products to the environment and human health to facilitate the growth of nanoindustry. Some wide-bandgap nanomaterials, such as TiO2, ZnO, CeO2 and metal nanoparticles have the capability to induce high photocatalytic activities (PCA) which refers to capacity of a material to promote a specific photochemical reaction in the presence of light related to their small size and comparatively large surface area. Also, the generation of reaction oxygen species (ROS) by these nanomaterials can cause oxidative stress, resulting in the phototoxicity in living organisms. In this study, we have observed PCAs of TiO2 nanoparticle suspension and its effect toward 3T3 cells with high sensitivity and low experimental uncertainties using the multiplexed assay technique. This method is applicable to the high-throughput screening of various nanomaterials and cells with FreSHtracer, which is a fluorescent probe that easily penetrates into cells for detection and quantification of intracellular reduced glutathione (GSH). The relationship between the nanomaterial PCA, concentration, UV light dose and ROS generation is presented.