Short-term oral exposure to low doses of nano-sized TiO2 and potential modulatory effects on intestinal cells.
The present study investigated potential modulatory effects of low doses of nano-sized titanium dioxide (TiO2) on intestinal cells in vivo and in vitro. After short-term exposure to TiO2 nanoparticles in rats, histopathological analysis of intestinal tissues indicated a gender-specific effect with increased length of intestinal villi in male rats only. Moreover the intestinal tissue showed nanoparticle deposition as revealed by ICP-MS determination of titanium. Increased serum testosterone levels were also detected. Considering the male-specific effects detected in vivo, the TiO2 nanoparticle interaction with intestinal cells was further characterized in vitro and the modulating effect of testosterone and a hormone-induced growth factor, namely Insulin-like Growth Factor 1 (IGF-1), was also assessed. Cytotoxicity assays and analysis of Reactive Oxygen Species (ROS) production showed neither cellular alteration nor oxidative stress for nanoparticles at low concentrations, even though they were able to penetrate intestinal cells, as revealed by electron microscopy. Cell treatments with nanoparticles in association with testosterone or IGF-1 showed increased cell proliferation, compared to nanoparticles or testosterone/IGF-1 alone. Since long-term intake of TiO2 nanoparticles at low doses is a relevant scenario for human exposure, attention should be given to the potential modulating activity of this nanomaterial on cell proliferation.
['Ammendolia|Maria Grazia|MG|', 'Iosi|Francesca|F|', 'Maranghi|Francesca|F|', 'Tassinari|Roberta|R|', 'Cubadda|Francesco|F|', 'Aureli|Federica|F|', 'Raggi|Andrea|A|', 'Superti|Fabiana|F|', 'Mantovani|Alberto|A|', 'De Berardis|Barbara|B|']
D000284:Administration, Oral D000818:Animals D004305:Dose-Response Relationship, Drug D000067493:Dynamic Light Scattering D005260:Female D019073:HT29 Cells D006801:Humans D007422:Intestines D008297:Male D053768:Metal Nanoparticles D008855:Microscopy, Electron, Scanning D017207:Rats, Sprague-Dawley D017382:Reactive Oxygen Species D013739:Testosterone D014025:Titanium D018675:Toxicity Tests
Low doses Modulatory effects Testosterone IGF-1 In vitro and in vivo studies Nano-sized TO(2)