0000000000749106
AUTHOR
Marie Carrière
Impact of Titanium Dioxide Nanoparticle Dispersion State and Dispersion Method on Their Toxicity Towards A549 Lung Cells and Escherichia coli Bacteria
International audience; Titanium-dioxide nanoparticle (TiO2-NPs) dispersion for toxicological studies is classically achieved by high power sonication. The aim of this study was to compare the dispersion state resulting from different dispersion techniques, and to correlate dispersion state and dispersion method to in vitro toxicity in a final view to contribute to the very active field of establishing protocols for reliable NP toxicity testing. To achieve this objective, several dispersion methods were applied to Evonik P25 TiO2-NPs. The dispersion state, as well as the stability of these TiO2-NP suspensions were evaluated by photon correlation spectroscopy (PCS) and turbidimetry. A549 hum…
PIXE ANALYSES OF THE SOLUBLE AND MEMBRANE SE-CONTAINING PROTEINS EXTRACTED FROMCUPRIAVIDUS METALLIDURANSCH34 AFTER SELENIUM OXIDES CHALLENGE
The soil bacterium Cupriavidus metallidurans CH34 resist selenite by reducing it into the insoluble and less toxic elemental selenium. Two mechanisms of reduction of selenium oxides in C. metallidurans CH34 were highlighted: assimilation leading to organic species and detoxification leading to precipitation of selenite in nanoparticules of elemental selenium. The alkyl selenide detected as an intermediate product during assimilation of selenite or as the major accumulated chemical form during assimilation of selenate was identified as selenomethionine.Soluble and membrane proteins were extracted from C. metallidurans CH34 submitted to selenium oxides challenge. After separation by SDS-PAGE,…