Nanoparticles (NPs) are presently introduced in a fast growing number of commercial products. Among them, titanium dioxide is found in daily use hygiene products or orally administered drugs. However its effects on gastrointestinal tract are poorly investigated. Here we focused on the translocation of TiO2 NPs through different models of gastrointestinal epithelia: Caco-2 enterocytes, HT29-MTX mucus-secreting cells and a co-culture of both types, more representative of the complexity of the digestive barrier. Once their integrity and functionality checked, they were exposed to anatase and rutile NPs, well characterized in terms of purity, size and crystallinity. After exposure, cyto- and genotoxicity were assessed together with the activity of enzymes responsible for cell redox balance preservation. Internalization was followed by TEM and μ-XRF elemental mapping, coupled to XAS analysis of Ti speciation, allowing to get insights on NPs fate after internalization. Ti contents in apical and basolateral compartments were determined by ICP-MS. TiO2 NPs surface modification after exposure to gastrointestinal fluids was investigated. A digestion model was thus developed, simulating the different compartments of a gastrointestinal tract. The originality of this project relies on the panel of techniques implemented to investigate digestive barrier translocation, bringing together biologists, chemists and physicists in a pluridisciplinary research program.< Leer menos