zinc sulfide content, %

Because of its unique properties, titanium dioxide is widely used and is well known in nanoscience and nanotechnology. Titanium dioxide was one of the first materials to be used in nanotechnology products. However, the potential toxicity of titanium dioxide nanoparticles is a controversial subject. Many cosmetic companies use titanium dioxide nanoparticles. Because of its bright whiteness, it is used in products such as paints, coatings, papers, inks, toothpaste, face powder, and food colouring.

It’s also used in food products to provide a white color. Candies, cakes and creamers are examples of foods that may contain titanium dioxide for its color enhancing and bleaching properties.

The ROS seemed to be endlessly produced by P25TiO₂NPs upon irradiation, since the values detected after 6 h are similar to the ones after 3 h. However, the amount of vitamin B2 in the surface of the NPs proved to be enough to decrease the ROS detected even after 6 h. Statistical analysis showed a significant difference between C and A. p < 0.05

Titanium dioxide is a versatile material with a wide range of applications. Some of its most common uses include:

The toxicity of P25TiO₂NPs was evaluated in both prokaryotic (Fig. 3) and eukaryotic cells (Fig. 4). The XTT assay was chosen to measure the cell viability in bacterial cultures of MSSA, a normal skin microbiota microorganism. The reduction in the viability of samples with bare NPs is notorious, possibly due to the described ROS production from the interaction of P25TiO₂NPs with light [37]. This effect seems to be avoided when they are functionalized with vitamin B2. Also, the most concentrated vitaminB2@P25TiO₂NPs sample (0.2 mg/mL) shows up to 60% more absorbance after 6 h compared to the bare NPs (due to normal cell replication). This may indicate that the antioxidant effect of the vitamin B2 coating is greater than the oxidation damage produced by the NPs. This protective capacity could be attributed to the glutathione redox cycle and the conversion of reduced riboflavin to its oxidized form [38]. Values of cell viability greater than 100% are not rare and could be understood because the XTT assay actually measure metabolic activity when reducing the tetrazole to formazan. It is usually assumed that conversion is dependent on the number of viable cells, but it could also be related to an expected increased enzymatic activity when cells are exposed to small doses of some new substance. Further analysis showed that this effect was not the only one responsible for better cell viability of vitaminB@P25TiO₂NPs treated samples.

The FDA first approved the use of titanium dioxide in food in 1966, following its 1960 removal (along with the removal of other color additives) from the agency's original Generally Recognized as Safe list. In 1977, titanium dioxide joined the list of color additives that are exempt from certification, which means titanium dioxide doesn't have to be listed on the packaging of every product it's used in, Faber noted.