Cytotoxicity of single-walled carbon nanotubes, multi-walled carbon nanotubes, and chrysotile to human lung epithelial cells

Abstract

Carbon nanotubes (CNTs) have found numerous applications in various industries. Recently, adverse effects of these materials on human and animal cells in vitro have been reported. In the present study, the cytotoxicity of single-walled carbon nanotubes (SWCNTs), multi-walled carbon nanotubes (MWCNTs), and chrysotile asbestos in human lung epithelial cells has been studied using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. The cells were exposed for 6 h and 24 h to between 0.97 and 1500 μg mL⁻¹ of CNTs and chrysotile fibers prepared in two culture media containing 5% serum and 0.5% dimethylsulfoxide. Dose–response curves were obtained to determine the nonobservable adverse effect concentration and the half-maximum inhibitory concentration (IC₅₀). The way of dispersion affects the cytotoxicity of CNTs. For MWCNT, the toxicological indexes were lower than for SWCNT. Chrysotile fibers were even less cytotoxic than CNTs. Therefore, workplace control measures are recommended as priority for occupational and environmental conditions.

Keywords:

• carbon nanotubes
• chrysotile
• cytotoxicity
• MTT assay
• human lung cells

Acknowledgments

This research has been supported by Tehran University of Medical Sciences (TUMS) for the financial support of this work, grant number (15196/2011). The authors are very grateful for all colleagues in the Department of Cellular and Molecular Nutrition, TUMS for their kind helps and advices in the laboratory.