Titanium dioxide nanoparticles inhibit proliferation and induce morphological changes and apoptosis in glial cells

Titanium dioxide nanoparticles (TiO2 NPs) are widely used in the chemical, electrical and electronic industries. TiO2 NPs can enter directly into the brain through the olfactory bulb and be deposited in the hippocampus region. We determined the effect of TiO2 NPs on rat and human glial cells, C6 and U373, respectively. We evaluated proliferation by crystal violet staining, internalization of TiO2 NPs, and cellular morphology by TEM analysis, as well as F-actin distribution by immunostaining and cell death by detecting active caspase-3 and DNA fragmentation. TiO2 NPs inhibited proliferation and induced morphological changes that were related with a decrease in immuno-location of F-actin fibers. TiO2 NPs were internalized and formation of vesicles was observed. TiO2 NPs induced apoptosis after 96 h of treatment. Hence, TiO2 NPs had a cytotoxic effect on glial cells, suggesting that exposure to TiO2 NPs could cause brain injury and be hazardous to health.