Differential toxic responses between pristine and functionalized multiwall nanotubes involve induction of autophagy accumulation in murine lung.

ABSTRACT

Carbon nanotubes (CNT) are becoming commonly used in industrial applications. However, the toxicity associated with this material remains to be established. The aim of this study was to investigate the potential toxic mechanisms associated with multiwall carbon nanotubes (MWCNT) in normal mouse lung. A total of 100 µg of two types of MWCNT, namely, pristine MWCNT (PMWCNT) and acid-treated-MWCNT (TMWCNT), was administered to male C57BL/6 mice via intratracheal (IT) instillation for a period of 6 mo. Our results indicated that PMWCNT induced pulmonary autophagy accumulation and resulted in more potent tumorigenic effects compared to TMWCNT. Accordingly, MWCNT may exert differential toxicity attributed to various physicochemical properties. Data emphasize the need for careful regulation of production and use of CNT.