mica and titanium dioxide manufacturers

A few non-dietary studies have reported adverse effects in the gastrointestinal tract of laboratory animals given food-grade TiO2. However, these same effects were not seen when the same or higher doses of food-grade TiO2 were administered in the animals' diet. Dietary studies best reflect how humans are exposed to TiO2 from food. Thus, the Food Directorate placed the most emphasis on the results of these studies in the state of the science report.

...

As mentioned above, these oxide NPs are harmful in part because both anatase and rutile forms are semiconductors and produce ROS. Particularly, P25 kind has band-gap energies estimated of 3.2 and 3.0 eV, equivalent to radiation wavelengths of approximately 388 and 414 nm, respectively. Irradiation at these wavelengths or below produces a separation of charge, resulting in a hole in the valence band and a free electron in the conduction band, due to the electron movement from the valence to conduction bands. These hole–electron pairs generate ROS when they interact with H2O or O2 [43,44]. It was described that they can cause an increase in ROS levels after exposure to UV-visible light [45]. The NBT assay in the studied samples showed that bare P25TiO2NPs produce a large amount of ROS, which is drastically reduced by functionalization with vitamin B2 (Fig. 5). This vitamin, also known as riboflavin, was discovered in 1872 as a yellow fluorescent pigment, [46] but its function as an essential vitamin for humans was established more than sixty years later, and its antioxidant capacity was not studied until the end of the XX century [47,48]. This antioxidant role in cells is partially explained because the glutathione reductase enzyme (GR) requires it for good functionality. This enzyme is the one in charge of the conversion of oxidized glutathione to its reduced form which acts as a powerful inner antioxidant and can quench the ROS [49,50]. The cost of this action is that the glutathione is converted to the oxidized form and needs to be recovered by the GR. Consequently, the cells need more vitamin B2. Another glutathione action is the protection against hydroperoxide. This activity is also mediated by riboflavin. Therefore, local delivery of this vitamin seems to significantly help the cells in their fight to keep the oxidative balance, once they are exposed to high levels of ROS.

...
{随机栏目} 2025-08-15 02:14 404
  • In conclusion, China's billion-ton TiO2 industry is a microcosm of the country's economic strength and industrial sophistication. It not only underscores China's manufacturing might but also highlights its ability to adapt and innovate in the face of challenges. As the world continues to grapple with the balance between economic progress and environmental sustainability, China's TiO2 sector will undoubtedly play a pivotal role in shaping the future of this critical industry.

    {随机栏目} 2025-08-15 00:44 155