Multi-walled carbon nanotubes induce cytotoxicity, genotoxicity and apoptosis in normal human dermal fibroblast cells

Multi-walled carbon nanotubes (MWCNT) have won enormous popularity in nanotechnology. Due to their unusual, one dimensional, hollow nanostructure and unique physicochemical properties they are highly desirable for use within the commercial, environmental and medical sectors. Despite their wide application, little information is known concerning their impact on human health and the environment. While nanotechnology looms large with commercial promise and potential benefit, an equally large issue is the evaluation of potential effects on humans and other biological systems. Our research is focused on cellular response to purified MWCNT in normal human dermal fibroblast cells (NHDF). Three doses (40, 200, 400 microg/mL) of MWCNT and control (tween-80+0.9% saline) were used in this study. Following exposure to MWCNT, cytotoxicity, genotoxicity and apoptosis assays were performed using standard protocols. Our results demonstrated a dose-dependent toxicity with MWCNT. It was found to be toxic and induced massive loss of cell viability through DNA damage and programmed cell-death of all doses compared to control. Our results demonstrate that carbon nanotubes indeed can be very toxic at sufficiently high concentrations and that careful monitoring of toxicity studies is essential for risk assessment.