Hazard assessment of benchmark metallic nanomaterials in alveolar epithelial cells

Abstract publicado em: Toxicology Letters. 2017;280 (Suppl 1):S180–S190. Disponível em: http://dx.doi.org/10.1016/j.toxlet.2017.07.523The fast development of nanotechnology has led to the manufacturing of a wide array of nanomaterials (NMs). Despite the number of studies addressing NMs toxicity, uncertainties about their safety remain, representing a challenge to regulatory authorities. This work intended to assess the toxicity of metallic NMs in alveolar epithelial cells and to relate the effects with their physicochemical properties. Benchmark NMs (JRC) - CeO2 (NM-212), TiO2 (NM-100) and BaSO4 (NM-220) - were dispersed and their properties in the culture medium were evaluated by DLS. A549 cells were exposed to each NM for cytotoxicity (MTT and plating efficiency assays) and genotoxicity (comet and cytokinesis-blocked micronucleus, CBMN, assays) assessment. A homogeneous dispersion that remained stable in culture medium was achieved for all NMs. The CeO2NM was the only one that decreased cells’ proliferative capacity after 8 days exposure. As to the genotoxicity, the TiO2NM significantly increased the level of DNA damage following 3h and 24h exposure, whereas the CeO2NM caused only a slight increase in DNA damage at 3h exposure. None of the NMs tested positive by the CBMN assay. BaSO4NM was neither cytotoxic nor genotoxic. In conclusion, this study contributed to the hazard assessment of different benchmark metallic NMs, disclosing diverse biological effects that will be interpreted considering the inherent physicochemical properties. The identification of key features and pathways that drive NMs’ toxicity is paramount to allow prediction of their adverse effects, avoiding the huge task of testing every new NM.Project NANoREG (GA 310584), ToxOmics (UID/BIM/00009/2013) and INSA (2013DGH860).