Thèse de doctorat en Sciences des matériaux, Physico-chimie des matériaux
Soutenue en 2014
à Nantes , dans le cadre de École doctorale Matériaux, Matières, Molécules en Pays de la Loire (3MPL) (Le Mans) , en partenariat avec Université de Nantes. Faculté des sciences et des techniques (autre partenaire) .
Le président du jury était Hynd Remita.
Pas de résumé disponible.
Characterizing the interaction between titanium dioxide and phospholipids in aqueous medium
The interaction of titanium dioxide nanoparticles with phospholipids, components of living membranes, was investigated in aqueous medium. The aim of this study was to understand (i) how metal-oxide (TiO222222312 2 ) affinity chromatography can separate phospholipids and (ii) TiO-living cells interactions at molecular level. At the macroscopic level, Langmuir film technique coupled with Laser Doppler Velocimetry revealed that the interactions between TiO-P25 particles and phospholipids are essentially charge-dependent. TiO-P25 particles interact strongly at acidic pH with 1,2-dimyristoyl-sn-glycero-3-phosphate (DMPA), 1,2-dimyristoyl-sn-glycero-3-phospho-rac-1-glycerol (DMPG) and 1',3'-bis[1,2-dimyristoyl-sn-glycero-3-phospho]-sn-glycerol (TMCL), and weakly with 1,2-dimyristoyl-sn-glycero-3-phospho-L-serine (DMPS). Other membrane lipids such as 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC), 1,2-dimyristoyl-sn-glycero-3-phosphoethanolamine (DMPE) and sphingomyelin (SM) did not interact with TiO-P25 regardless of pH. The interactions of DMPA and DMPG, the main phospholipid adsorbing on TiO-P25 particles, with pure anatase and rutile crystallites were evidenced by surface tension measurements, batch adsorption experiments, Infrared spectroscopy, Raman spectroscopy and P NMR. DMPA adsorbs solely at acidic pH on anatase and rutile, through electrostatic interactions implying the phosphate moiety. In contrast, DMPG adsorbs on TiOat both acidic and basic pH mainly by non-electrostatic interactions, through the glycerol moiety and weakly through the phosphate group. The Ti (IV) sites and surface hydroxyl groups on TiOwere suggested to be involved into the interaction with phospholipids