Increasing attention is being given to research that makes use of the high bio-permeability of near-infrared light to perform in vivo imaging using a near-infrared fluorescent nanomaterial.

Unlike other near-infrared fluorescent nanomaterials, single-walled carbon nanotubes (SWCNTs) do not fade easily and also have low toxicity, so SWCNT is expected to contribute to medical research using animal experiments.

Through joint research with the National Center for Global Health and Medicine and Hokkaido University, mouse whole-body near-infrared fluorescence (NIRF) contrast imaging and tissue observation using a newly developed NIRF microscope were performed by using SWCNTs coated with phospholipid polyethylene glycol as a probe for NIRF. The researchers discovered that SWCNTs accumulated in the brown adipose tissue (BAT) in fasted mice. Furthermore, they found that this phenomenon occurred due to SWCNT leakage out of BAT blood vessels caused by increase in vascular wall permeability.

It is expected that mouse whole-body NIRF contrast imaging using SWCNTs and tissue observation at the cellular level using a NIRF microscope will aid in the discovery of organ and tissue abnormalities and clarification of the corresponding mechanisms, and contribute to the development of drugs and treatments.