The cytotoxic and genotoxic potential of titanium dioxide (TiO2) nanoparticles on human SH-SY5Y neuronal cells in vitro

Titanium dioxide (TiO2) nanoparticles are one of the most commonly used nanomaterials. They are used in plastics, sunscreens, personal care products, pharmaceuticals and the food industry due to their photocatalytic properties, high refractive index and generally unreactive nature. Their vast range of applications, and hence potential exposure to humans, raises concern over the safety of the nanomaterial. TiO2 nanoparticles have been extensively studied; however, their toxic effect on humans is still poorly understood, particularly the adverse effects they may have on the nervous system. In vivo studies have shown that TiO2 nanoparticles are able to enter the brain via circulation and through the olfactory pathway. Because of their potential genotoxicity and carcinogenic effect, the aim of this study was to assess the cytotoxic and genotoxic potential of TiO2 nanoparticles on human SHSY5Y neuronal cells. Anatase TiO2 nanoparticles were used in this experiment due to their extensive use in industry. Results obtained from this study show that TiO2 nanoparticles are able to induce DNA damage in neuronal cells at concentrations of 3000μM (239.61μg/ml) after 24 and 48 hours of exposure, but do not significantly alter cell viability even at concentrations as high as 10,000 μM (798.66 μg/ml). Cell morphology, as determined by scanning electron microscopy, was also unaltered in this study. Further study is required to determine cell internalisation and the mechanisms behind the genotoxicity induced by TiO2 nanoparticles