In vivo pulmonary genotoxicity of multiwalled-carbon nanotubes

Carbon nanotubes (CNTs) are newly developed nanomaterials with unique chemical and physical properties. Exposure to airborne CNTs in occupational settings or via consumer products is expected to increase significantly within the next decade due to the vigorous synthesis and applications of these materials in numerous consumer and industrial activities. Previous studies have shown that multiwalled CNT (MWCNT) induce pulmonary inflammation and pulmonary fibrosis. In the present study, we investigated genotoxic potential of MWCNTs. Female MutaMouse were exposed to 42.7 ug/mouse or 128 ug/mouse doses of MWCNTs Mitsui XNRi-7 or NM 401 once a week for four consecutive weeks. Doses were administered via intratracheal instillation. Lung tissues were collected 56 days post-exposure. Bronchoalveolar lavage(BAL) fluid cellularity, BAL and lung tissue DNA damage (COMET assay), lacz mutation frequency and global gene expression changes in lung tissue were determined. This experiment examined the pulmonary response of male mice exposed to Mitsui XNRi-7 and NM 401 once a week for 4 consecutive weeks via intratracheal instillation at two doses, including 42.7µg/mouse and 128µg/mouse and vehicle control. Each dose group was examined 56 days following the final exposure. Each dose group had 4-5 biological replicates. There were a total 26 samples (arrays) from the lung included in the final analysis using a two-colour reference design.