Interactions between TiO2 nanoparticles and biomolecules

Hélène TERRISSE, Sophie QUILLARD, Bernard HUMBERT

Titanium dioxide (TiO₂, identified as a food additive noted E171) is currently present as particles in numerous food formulations (such as confectionary and dairy products), as well as in various drugs (coated tablets), where it is used for its whiteness and shiny appearance.

However, for the moment, little information is available about the possible toxicity of these particles (which may present nanometric size) introduced in food formulations. In this context, we study, in collaboration with INRA of Nantes (Marie-Hélène ROPERS, BIA team) the interactions involved between titanium dioxide and biomolecules existing in food products or in the gastro-intestinal tract.

Our first research axis consists in studying the adsorption mechanisms of phospholipid molecules, the main constituents of cell membranes, onto the TiO₂ surface, in order to identify the possibility for TiO₂ to cross these membranes and reach the cell nucleus. Studying these interactions requires a large panel of experimental tools, such as Langmuir trough, zeta potential measurements, as well as Infrared and NMR spectroscopy. Our second research axis aims at determining the whole set of physico-chemical characteristics of E171 particles obtained from various suppliers or extracted from candy coatings, and then studying their evolution all along the gastro-intestinal tract.