Abstract
Main advantages of the optical imaging technique achieving high spatio-temporal resolution, non-radiation, less cytotoxicity and low cost with small devices as compared to conventional clinical imaging techniques such as CT, MRI and PET. In particular, near infrared (NIR) fluorescence imaging enables us to visualize deep portion of tissues due to the excellent penetration in vivo. We developed a NIR fluorophore-conjugated anti-Carcinoembryonic antigen (CEA) antibody for mice bearing tumor of CEA expressing cells, and demonstrated in vivo optical imaging by two-photon excitation microscopy. In the result, CEA-expressing cancer cells were specifically detected in vivo. In preclinical applications, the lymph node micrometastasis was also successfully visualized by two-photon excitation microscopy. These results suggest that two-photon excitation microscopy in combination with the immunoconjugated NIR fluorescence probe could be widely adapted to cancer detection in clinical settings or various cancer metastasis model to reveal the mechanism of cancer metastasis and to visualize microenvironment which may consist of cancer cells and stroma cells.
