Fluorescent nanotubes enhance mouse imaging

May 30, 2011

Researchers at Stanford University have developed a better way of imaging mouse innards using fluorescent carbon nanotubes.

The fluorescent imaging method, which uses fluorescent dyes, offers poor resolution at tissue depths of more than a few millimeters. The fluorescent nanotube method —  injecting the mouse with nanotubes that then circulate in the bloodstream and diffuse into every organ — offers sharp resolution for organs several centimeters deep.

The nanotubes are particularly useful for imaging because they fluoresce under wavelengths of infrared light between 1,000 and 1,400 nanometers (nm), in contrast to most biocompatible dyes, which fluoresce at around 900 nm. Because tissue fluoresces naturally under light with a wavelength of around 900 nm, this creates an undesirable background glow that obscures imaging. So the nanotubes provide a sharper picture.

The nanotube imaging method allows simultaneous drug delivery and imaging, tagging the drug with the fluorescent nanotubes and revealing its diffusion path in real time.