Authors: L.M. Jakubek, J. Raingo, D. Lipscombe, R.H. Hurt
Affilation: Brown University, United States
Pages: 78 - 81
Keywords: SWNT, calcium ion channel, yttrium
The calcium ion channel is a voltage gated channel that enables calcium to enter electrically active cells. Proper function of these channels is essential for gene expression, neuronal excitability, muscle contraction and the release of neurotransmitters and hormones. As carbon nanotubes are electrically conductive and hydrophobic, they may interact with cell membranes and ion channels and adversely affects cells that depend on membrane potential for proper function. In this study, tsA201 cells were transfected with the CaV2.2 neuronal calcium ion channel and exposed to aryl-sulfonated SWNTs prior to electrophysiological characterization. As-produced SWNTs were found to strongly inhibit calcium channel function. Surprisingly, the same inhibitory dose response curve was seen in supernatant solutions after the nanotubes were removed by centrifugation. Careful study of this system reveals that the inhibitory effect is due to soluble yttrium ion that is mobilized from residual catalyst nanoparticles imbedded in these arc-synthesized SWNTs. The result emphasizes the need to carefully investigate the mechanistic origin and material basis for biological impacts of complex nanostructures.