Potential pulmonary effects of engineered carbon nanotubes: in vitro genotoxic effects

Abstract

The development of novel engineered nano-sized materials is a rapidly emerging technology with many applications in medicine and industry. In vitro and in vivo studies have suggested many deleterious effects of carbon nanotube exposure including granulomatous inflammation, release of cytosolic enzymes, pulmonary fibrosis, reactive oxygen damage, cellular atypia, DNA fragmentation, mutation and errors in chromosome number as well as mitotic spindle disruption. The physical properties of the carbon nanotubes make respiratory exposure to workers likely during the production or use of commercial products. Many of the investigations of the genotoxicity of carbon nanotubes have focused on reactive oxygen mediated DNA damage; however, the long thin tubular-shaped carbon nanotubes have a striking similarity to cellular microtubules. The similarity of carbon nanotubes to microtubules suggests a potential to interact with cellular biomolecules, such as the mitotic spindle, as well as the motor proteins that separate the chromosomes during cell division. Disruption of centrosomes and mitotic spindles would result in monopolar, tripolar, and quadrapolar divisions of chromosomes. The resulting aneuploidy is a key mechanism in the potential carcinogenicity of carbon nanotubes.

Keywords::

• Genotoxic
• mitotic spindle
• microtubule
• carbon nanotube
• aneuploid

Acknowledgements

We would like to thank Mr Michael Gipple, Scientific Illustrator, Scientific Arts, LLC, 198 Tyrone Road, Morgantown, WV 26508, USA, for the elegant drawing of the mitotic spindle and the 3-D reconstruction of the mitotic spindle. The authors are grateful to Ms Kimberly Clough Thomas, National Institute for Occupational Safety and Health (NIOSH), 1095 Willowdale Road, Morgantown, WV 26505, for her assistance with the Figures for the manuscript.

Disclaimer: The findings and conclusions in this report are those of the authors and do not necessarily represent the views of the National Institute for Occupational Safety and Health.

Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.