Abstract
Electromagnetic waves in the near-infrared (NIR) region have relatively high tissue permeability and are
expected to be applied not only to small animals for research but also in human clinical practices. In
molecular imaging, a molecular target probe is used to visualize the functions of the targeted molecules
and find specific diseases. To date, various near-infrared fluorescence and photoacoustic imaging methods
have been developed. Molecular-targeted phototherapy, or NIR-Photoimmuno therapy (PIT), was
developed using photochemical reactions induced by near-infrared light and approved in Japan in 2020.
In NIR-PIT, antibody-photoabsorber conjugates are used as a drug. NIR light specifically activates the
drug on the cancer cell membrane, causing irreversible damage to the cell membrane.
