Cytotoxic Effects of Short Multi-Wall Carbon Nanotubes in Dorsal Root Ganglion (DRG) Neurons

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

Keywords: short multi-wall carbon nanotubes, neurotoxicity of carbon nanotubes, dorsal root ganglion neurons, peripheral nervous system, neurotoxicity of carbon nanotubes

Summary:

Because of their unique physico-chemical properties, carbon nanotubes (CNTs) have found their way into diverse industrial and biomedical applications. Their escalating uses in multiple industries result in enhanced occupational human exposure to CNTs. However, the human health hazard of exposure to CNTs has not been assessed. Furthermore, the effects of CNTs on the nervous system and/or neural cells are virtually unknown. Because the putative neurotoxicity of CNTs has not been reportedly studied, we have investigated the putative cytotoxic effects of both funtionalized (i.e., carboxylated and hydroxylated) and non-functionalized short multi-wall carbon nanotubes (SMWCNTs) on dorsal root ganglion (DRG) neurons, an excellent model in vitro of neurons derived from the peripheral nervous system (PNS). We found SMWCNTs induced concentration-related decreases in survival and growth of DRG neurons, the non-functionalized ones being more cytotoxic than the functionalized ones, especially at the higher treatment concentrations. Treatment of DRG neurons with non-functionalized SMWCNTs induced necrotic damage and/or cell death in the neurons and decreased their expression of phospho-Akt, a cell survival and proliferation signal. Thus, our results may have pathophysiological implications in how exposure to SMWCNTs impacts on the structure and function of the PNS.