ABSTRACT
As carriers targeting neurons, their effects on the functional activities of neurons must be made clear. Many excellent studies have provided rich knowledge on this issue. Ion channels are important functional nanostructures in neurons. Park et al. (2003) have provided evidence that CNTs can affect the function of ion channels although their experiments were done with non-nerve cells. They exposed Chinese hamster ovary cells expressing a variety of potassium ion channels to unmodifi ed SWCNTs of varying diameter and the effects of CNTs were determined by whole-cell current recordings. SWCNTs affected all the types of potassium ion channel that were expressed, with human ether-a-go-go-related gene channels showing the greatest inhibition on current. Small-diameter CNTs (0.9 nm), such as SWCNTs, had the greatest blocking ability and the effects were concentration-dependent and reversible, while large-diameter MWCNT have no blocking effects on the channel activity. It is speculated that the CNTs may sit in or on top of the channel pore and interrupt ion fl ux and transition of the channel between the open and inactive states.
