Entry of Short Multi-Wall Carbon Nanotubes into Dorsal Root Ganglion (DRG) Neurons Induces Cell Death

J.C.K. Lai, W. Gao, A. Bhushan, S.E. Bearden, L. McDougall, S.W. Leung
Idaho State University College of Pharmacy, US

Keywords: nanotoxicity, neurotoxicity, carbon nanotubes, peripheral nervous system, entry into neurons


Carbon nanotubes (CNTs) have found their way into diverse industrial and biomedical applications because of their unique physico-chemical properties. However, the human health impact of exposure to CNTs is unknown. Our recent and ongoing studies focus on the putative cytotoxicity of CNTs in neural cells as neurotoxicity of CNTs has not been reportedly studied. We have therefore investigated the putative cytotoxic effects of two functionalized, namely carboxylated and hydroxylated, and non-functionalized short multi-wall carbon nanotubes (SMWCNTs) on dorsal root ganglion (DRG) neurons, which constitute an excellent model in vitro of neurons derived from the peripheral nervous system (PNS). We hypothesized that treatment with CNTs induces a dose-related decrease in the viability of DRG neurons and functionalization of CNTs modulates the cytotoxicity profile of CNTs. Employing confocal microscopy, we found that exposure of DRG neurons to SMWCNTs resulted in the entry of the SMWCNTs into the cytoplasm of the neurons. Apparently, concomitant with the entry of SMWCNTs into DRG neurons, their survival was greatly decreased dependent on the levels of SMWCNTs, the non-functionalized being more cytotoxic than the functionalized SMWCNTs. Thus, our results may have pathophysiological implications in how exposure to SMWCNTs impacts on the structure and function of the PNS.