Assessment of biocompatibility in prokaryotic cells

Nano-sized TiO₂ generally shows low or no acute toxicity in both invertebrates and vertebrates. However, exposure of Daphnia magna to 20 ppm TiO₂ for 8 consecutive days was found to cause 40 % mortality. Zhu et al. showed minimal toxicity to D. magna after 48 h exposure, while upon chronic exposure for 21 days, D. magna suffered severe growth retardation and mortality. A significant amount of nano-sized TiO₂ was found also accumulated in the body of the animals. Similar findings with coated nano-sized TiO₂ (T-Lite™ SF, T-Lite™ SF-S and T-Lite™ MAX; BASF SE) were reported by Wiench et al. Biochemical measurements showed that exposure to TiO₂ NPs induces significant concentration-dependent antioxidant enzyme activities in D. magna. Lee et al. showed that 7 and 20 nm-sized TiO₂ induced no genotoxic effect in D. magna and in the larva of the aquatic midge Chironomus riparius.

Références

Titanium dioxide safety is evaluated by regulatory agencies all over the world based on scientific studies.

It should also be considered that due to the low pH in the stomach, the increased dissolution of the TiO₂ particles may increase its bioavailability and may facilitate the entry of titanium ions into the blood circulation. Despite the relatively large consumption of TiO₂ as a food additive, no studies on the effect of pH on its absorption and bioavailability have been found in the literature. This can be attributed to a general belief that TiO₂is completely insoluble. However, this is not completely true, as TiO₂ particles show a certain degree of solubility.

Assessment of biocompatibility

Still, in 2016 Skittles publicly declared it would get rid of the chemical compound in its products, according to a press release at the time from the Center for Food Safety, which called the substance harmful and potentially poisonous. But the ingredient remains, according to the lawsuit, which alleges the candy company is misleading consumers by not having eliminated titanium dioxide.