[Optical nano-imaging for the diagnosis of gastrointestinal cancers]

Development of in vivo animal imaging instrumentations and methods contributes to the early diagnosis of cancer. Of variable imaging modalities, in vivo optical imaging such as bioluminescence and fluorescence is one of the best methods to measure molecular change of cancer cells. High sensitivity and relatively low cost of optical method gives benefits to apply for translational research in the field of cancer. Nano-probes to label and detect early cancer cells have been developed by nano-chemists and molecular imaging researchers. Quantum dots made from fluorescent semi-conductors show good advantages in term of imaging probes; high quantum yields, large molar extinction coefficients, size-dependent tunable emission and high photostability. To detect a gastrointestinal (GI) cancer, newly developed endoscopes have been used. Among them, near infrared fluorescence endoscope and confocal endomicroscope are good candidates for clinical application. In animal studies, successful results to detect cancer in gastrointestinal tract have been obtained. Prospect of nanoparticles as optical imaging moiety is promising to detect GI cancers if their toxicity is minimized. Future fluorescence confocal endoscope with safe cancer targeting nanoparticles will be useful for the detection and treatment of GI cancers.