An advanced in situ imaging method using heavy metal-doped hollow tubes to evaluate the biokinetics of carbon nanotubes in vivo

We made ‘Gd-peapod’, which is a double-walled carbon nanotube filled with gadolinium chloride. After Gd-peapods were injected to a rat via tail vein, we evaluated the organs by magnetic resonance imaging (MRI). As a result, the peapods in rats were easily visualized by MRI and the change in signal intensity was dose dependent. This newly developed method can be used to monitor carbon nanotube biokinetics in vivo without tedious tissue preparation.