Researchers at Rice University have come up with a better X-ray contrast agent, which may allow for very precise tracking of cells, biomolecules, and other particles within the body. In particular, the researchers believe that seeing whether stem cells are moving towards and healing diseased tissue will be one of the first important applications for this technology.
The particles consist of very short (20-80 nm) nanotubes, along with bismuth groups attached to them. To conjugate the bismuth clusters to the carbon nanotubes, the researchers discovered that they had had to make imperfections within the nanotubes.