Exposure to Carbon Nanotube Material: Assessment of Nanotube Cytotoxicity using Human Keratinocyte Cells

TLDR

Carbon nanotubes, a novel class of carbon allotropes with unique electrical, mechanical, and thermal properties, are employed in electronics, aerospace, and computing, yet exposure to graphite and related carbon materials has been linked to skin diseases such as dermatitis, hyperkeratosis, and naevi. The study examined the adverse effects of single‑wall carbon nanotubes on immortalized human epidermal keratinocytes (HaCaT) in vitro. Exposure of HaCaT cells to SWCNT for 18 h induced oxidative stress, peroxidative damage, antioxidant depletion, loss of viability, and ultrastructural alterations. These results indicate that dermal exposure to unrefined SWCNT can cause skin toxicity through accelerated oxidative stress.

Abstract

Carbon nanotubes are new members of carbon allotropes similar to fullerenes and graphite. Because of their unique electrical, mechanical, and thermal properties, carbon nanotubes are important for novel applications in the electronics, aerospace, and computer industries. Exposure to graphite and carbon materials has been associated with increased incidence of skin diseases, such as carbon fiber dermatitis, hyperkeratosis, and naevi. We investigated adverse effects of single-wall carbon nanotubes (SWCNT) using a cell culture of immortalized human epidermal keratinocytes (HaCaT). After 18 h of exposure of HaCaT to SWCNT, oxidative stress and cellular toxicity were indicated by formation of free radicals, accumulation of peroxidative products, antioxidant depletion, and loss of cell viability. Exposure to SWCNT also resulted in ultrastructural and morphological changes in cultured skin cells. These data indicate that dermal exposure to unrefined SWCNT may lead to dermal toxicity due to accelerated oxidative stress in the skin of exposed workers.