Vanadium Pentoxide-Coated Ultrafine Titanium Dioxide Particles Induce Cellular Damage and Micronucleus Formation in V79 Cells

Abstract

Surface-treated titanium dioxide (TiO₂) particles coated with vanadium pentoxide (V₂O₅) are used industrially for selective catalytic reactions such as the removal of nitrous oxide from exhaust gases of combustion power plants (SCR process) and in biomaterials for increasing the strength of implants. In the present study, untreated ultrafine TiO₂ particles (anatase, diameter: 30–50 nm) and vanadium pentoxide (V₂O₅)-treated anatase particles were tested for their cyto- and genotoxic effects in V79 cells (hamster lung fibroblasts). Cytotoxic effects of the particles were assessed by trypan blue exclusion, while genotoxic effects were investigated by micronucleus (MN) assay. In addition, the generation of reactive oxygen species (ROS) was determined by the acellular method of electron spin resonance technique (ESR) and by the cellular technique of determination of thiobarbituric acid-reactive substances (TBARS). Our results demonstrate that V₂O₅-treated TiO₂ particles induce more potent cyto- and genotoxic effects than untreated particles. Further, acellular and cellular radical formation was more pronounced with V₂O₅-anatase than untreated anatase. Thus, data indicate that V₂O₅-treated TiO₂ particles were more reactive than natural anatase and capable of inducing DNA damage in mammalian cells through production of free radicals.