Effects of carbon nanotube exposure on mouse lungs

<p>Carbon nanotubes (CNTs) are attracting attention as a next-generation nanomaterial with potential for a wide range of engineering applications. However, it is concerned that its high aspect ratio needle shape and high biodurability may cause asbestos-like toxicity. The aim of this study was to investigate the role of Nrf2 in the effects of multi-walled carbon nanotubes (MWCNTs) on the lung through exposure by pharyngeal aspiration. Nrf2 null or C57BL/6JJcl wild-type male mice were exposed to short or long Nanocyl MWCNT dispersed in Dispersion medium (DM) at 0, 10 and 20 μg per mouse by pharyngeal aspiration. Seven days later, the bronchoalveolar lavage fluid (BALF) of the mice was collected. The total number of cells or macrophages in the BALF was significantly different only between the control group and the long MWCNT 20 μg group in wild-type mice. Histopathological study revealed that exposure to long MWCNT increased granuloma with retention of MWCNT in the lung of wild-type mice, The study suggests that inflammatory responses are induced by exposure to long MWCNT in wild-type mice, but are attenuated by Nrf2 deletion. Length of MWCNTs was also implicated as a factor for induction of inflammation.</p>