Hazards of nanotechnology: effect of titanium dioxidenanoparticles on the liver and renal cortex of albino rats.An electron microscopic study

IntroductionExposure to titanium dioxide nanoparticles (TiO2 NPs) results from its wide usein the fields of medicine, industry, engineering, and environmental technology.ObjectivesTo investigate the effect of administration of TiO2 NPs on the ultrastructure of the ratliver and renal cortex.Materials and methodsRats were subdivided into two groups: group A (served as control) and group B(TiO2 group). TiO2 was suspended in PBS and administered by an oral gavage to therats of group B daily for 90 days at a dose of 5 mg/kg body weight. Thereafter, groupB was subdivided into group B1 and sacrificed 24 h after the last dose of titanium.Group B2 was left untreated for 12 months and then sacrificed. Specimens from theliver and renal cortex were obtained and processed for examination by transmissionelectron microscopy.ResultsHistopathological changes were detected in the hepatocytes of group B1 in theform of dilated rough endoplasmic reticulum, numerous lysosomes, and abnormalmitochondria. Moreover, accumulation of large lipid droplets and wide cytoplasmicvacuoles was observed. The renal cortex was also affected. Numerous lysosomeswere observed in the lining cells of the proximal tubules and the glomerulus showedan apparent increase in the number of mesangial cells. The interstitium was thesite of excessive collagen bundles. These hepatic and renal cortical changes werepartially ameliorated 12 months after the last dose of TiO2.ConclusionSmall doses of TiO2 NPs for a long duration resulted in a variety of degenerativechanges in the rat liver and renal cortex. Therefore, further studies are required toinvestigate the underlying mechanisms of this toxicity and to search for possibleprotective measures.