Systematic Influence Induced by 3 nm Titanium Dioxide Following Intratracheal Instillation of Mice

This work reported the systematic influence of titanium dioxide nanoparticles (TiO₂ NPs) with a diameter of 3 nm on mice. Mice were repeated intratracheally instilled with TiO₂ NPs, once per-week for 4 consecutive weeks, at total dose of 13.2 mg/kg. At 28 days post-instillation, the biochemical parameters in broncboalveolar lavage fluid (BALF) and brain homogenate as well as histopathologic changes of tissues were examined to describe the subacute toxicity of instilled TiO₂ NPs. The results showed that instilled TiO₂ NPs could induce lung damage, and change the permeability of alveolar-capillary barrier. The TiO₂ NPs were able to get access to blood circulation and reach extrapulmonary tissues, then lead to injury at the different level, such as liver and kidney. Our results also indicated that TiO₂ NPs might pass through the blood–brain barrier (BBB), and induce the brain injury through oxidative stress response.