Amorphous silica is largely used in many products including foods, cosmetics, paints and as vector for drug delivery. However, still limited data on its potential health hazard are available. The aim of this study was to investigate the cytotoxic and genotoxic potential of silica particles characterized by different size (250 and 500 nm) and structure (dense and mesoporous). Dense silica spheres (DS) were prepared by sol-gel synthesis, mesoporous silica particles (MCM-41) were prepared using the hexadecyltrimethylammonium bromide as structure directing agent and the tetraethylorthosilicate as silica source. Particles were accurately characterized by dynamic light scattering, nitrogen adsorption, X ray diffraction and field emission scanning electron microscopy. Murine macrophages (RAW264.7) and human epithelial lung (A549) cell lines were selected as representative of occupational and environmental exposure. Genotoxicity was evaluated by Comet assay and Micronucleus test. Cytotoxicity was tested by Trypan blue method. Cells were treated with 0-5-10-20-40-80 µg/cm2 of different silica powders for 4 and 24 hrs. The intracellular localization of silica was investigated by Transmission Electron Microscopy. Amorphous particles penetrated into the cell being compartmentalized in endocytic vacuoles. DS and MCM-41 particles induced cytotoxic and genotoxic effects in A549 and RAW264.7, although with different extent in the two cell lines. A549 were resistant, in term of cell viability, while showed a generalized induction of DNA strand breaks. RAW264.7 were susceptible to amorphous silica exposure, exhibiting both cytotoxic and genotoxic responses, expressed as DNA fragmentation and chromosomal alterations. The cytotoxic response of RAW264.7 was particularly relevant after MCM-41 exposure. The genotoxicity of amorphous silica highlights the need for a proper assessment of its potential hazard for human health.
|Autori interni:||GUIDI, PATRIZIA|
|Autori:||Guidi P; Nigro M; Bernardeschi M; Scarcelli V; Lucchesi P; Onida B; Mortera R; Frenzilli G|
|Titolo:||Genotoxicity of amorphous silica particles with different structure and dimension in human and murine cell lines|
|Anno del prodotto:||2013|
|Digital Object Identifier (DOI):||10.1093/mutage/ges068|
|Appare nelle tipologie:||1.1 Articolo in rivista|