Toxicity evaluation of TiO2 nanoparticles embedded in toothpaste products

The present study evaluates the toxicity of titanium dioxide nanoparticles (TiO₂ NPs) that were extracted from toothpaste products by solid-liquid extraction method. The NPs structures were characterized using X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR) and scanning electron microscope (SEM). Ultraviolet spectrophotometer (UV) was also used to determine the band gab energy of these NPs. The XRD results indicated that the mixture of TiO₂ NPs was formed (anatase and rutile titanium dioxide nanoparticles). XRD results also indicated the crystalline size of NPs, which were small and ranging from 2.5 to 53.2 nm. The toxicity effect of TiO₂ NPs was evaluated on Chlorella vulgaris micro marine algae over 3 days. The results indicate a negative effect on the growth algae and concentration of chlorophyll a during the early growth stages. In contrast, at the late growth stages these NPs had a positive effect. Also, the toxicity effect of TiO₂ NPs was evaluated on Jurkat, HepG2, T-47D and S180 cancer cell lines. Cells were cultured with various concentrations of TiO₂ NPs (10, 20, 50, 100 and 200 µg/mL) for 48 hours using the Water-Soluble Tetrazolium (WST) method. The results showed that the TiO₂ NPs had a negative effect on the growth of the Jurkat, T-47D and S180 cancer cell lines. In contrary, a positive effect was seen on the HepG2 cell line.