Assessment of dermal irritation potential of MWCNT

There is an increasing concern regarding the potential toxicity of nanoparticles (NPs), but little literature is available on its skin toxicity and irritation potential. We investigated whether multi-walled carbon nanotubes (MWCNTs) affect skin irritation using HaCaT cell line, the human skin equivalent model (HSEM), and anin vivo model. We evaluated the cytotoxic effects of MWCNTs on HaCaT cells and the HSEM. To confirm in vitro results, we evaluated the irritation potentials of MWCNTs on rabbit skin. In MTT assay, MWCNTs cytotoxicity depended on the concentration of MWCNTs in HaCaT cells. The HSEM skin irriation experiments revealed that MWCNTs have no irritation potential. These HSEM data are consistent with Draize skin irritation test. MWCNTs did not induce the cutaneous irritation of rabbit skin. We suggest that MWCNTs do not induce any acute cutaneous irritation and the HSEM offers a useful alternative method for evaluating the toxicities of toxicants including NPs.