Aqueous synthesis and concentration-dependent dermal toxicity of TiO 2 nanoparticles in Wistar rats

Abstract

A number of dermal toxicological studies using TiO 2 nanoparticles exist which are based on the study of various animal models like mice, rabbits etc. However, a well-defined study is lacking on the dermal toxic effects of TiO 2 nanoparticles on rats, which are the appropriate model for systemic absorption study of nanoparticles. Furthermore, toxicity of TiO 2 nanoparticles varies widely depending upon the size, concentration, crystallinity, synthesis method etc. This study was conducted to synthesize TiO 2 nanoparticles of different sizes (∼15 to ∼30 nm) by aqueous method, thereby evaluating the concentration-dependent toxicological effects of the ∼20-nm sized nanoparticles on Wistar rats. Characterization of the particles was done by transmission electron microscope, dynamic light scattering instrument, X-ray diffractrometer, and ultraviolet spectrophotometer. The toxicity study was conducted for 14 days (acute), and it is observed that TiO 2 nanoparticles (∼20 nm) at a concentration of 42 mg/kg, when applied topically showed toxicity on rat skin at the biochemical level. However, the histopathological studies did not show any observable effects at tissue level. Our data suggest that well-crystallized spherical-shaped ∼20 nm anatase TiO 2 nanoparticles synthesized in aqueous medium can induce concentration-dependent biochemical alteration in rat skin during short-term exposure. © 2011 Springer Science+Business Media, LLC.