TY - JOUR T1 - Genotoxicity evaluation of nanosized titanium dioxide, synthetic amorphous silica and multi-walled carbon nanotubes in human lymphocytes. JF - Toxicol In Vitro Y1 - 2014 A1 - Tavares, Ana M A1 - Louro, Henriqueta A1 - Antunes, Susana A1 - Quarré, Stephanie A1 - Simar, Sophie A1 - Pieter-Jan De Temmerman A1 - Eveline Verleysen A1 - Jan Mast A1 - Jensen, Keld A A1 - Norppa, Hannu A1 - Nesslany, Fabrice A1 - Silva, Maria João KW - Adult KW - Female KW - Humans KW - In Vitro Techniques KW - Light KW - Lymphocytes KW - Male KW - Micronucleus Tests KW - Microscopy, Electron, Transmission KW - Mutagenicity Tests KW - Nanostructures KW - Nanotubes, Carbon KW - Particle Size KW - Scattering, Radiation KW - Silicon Dioxide KW - Titanium AB -

Toxicological characterization of manufactured nanomaterials (NMs) is essential for safety assessment, while keeping pace with innovation from their development and application in consumer products. The specific physicochemical properties of NMs, including size and morphology, might influence their toxicity and have impact on human health. The present work aimed to evaluate the genotoxicity of nanosized titanium dioxide (TiO2), synthetic amorphous silica (SAS) and multiwalled carbon nanotubes (MWCNTs), in human lymphocytes. The morphology and size of those NMs were characterized by transmission electron microscopy, while the hydrodynamic particle size-distributions were determined by dynamic light scattering. Using a standardized procedure to ensure the dispersion of the NMs and the cytokinesis-block micronucleus assay (without metabolic activation), we observed significant increases in the frequencies of micronucleated binucleated cells (MNBCs) for some TiO2 NMs and for two MWCNTs, although no clear dose-response relationships could be disclosed. In contrast, all forms of SAS analyzed in this study were unable to induce micronuclei. The present findings increase the weight of evidence towards a genotoxic effect of some forms of TiO2 and some MWCNTs. Regarding safety assessment, the differential genotoxicity observed for closely related NMs highlights the importance of investigating the toxic potential of each NM individually, instead of assuming a common mechanism and equal genotoxic effects for a set of similar NMs.

VL - 28 CP - 1 U1 - http://www.ncbi.nlm.nih.gov/pubmed/23811260?dopt=Abstract M3 - 10.1016/j.tiv.2013.06.009 ER -