A new infrared fluorescent-Labeling agent and labeled antibody for diagnosing microcancers

• Published in: Bioorganic & medicinal chemistry 2003-07, Vol.11 (15), p.3289-3294
• Main Authors: Tadatsu, Masaya, Ito, Susumu, Muguruma, Naoki, Kusaka, Yoshihiro, Inayama, Kumi, Bando, Terumi, Tadatsu, Yoko, Okamoto, Koichi, Kunio, Nagao, Yoshimitsu, Sano, Shigeki, Taue, Hiromi
• Format: Article
• Language: English
• Subjects: Biological and medical sciences; Digestive system; Gastric Mucosa - chemistry; Humans; Indocyanine Green - analysis; Investigative techniques, diagnostic techniques (general aspects); Medical sciences; Microscopy, Fluorescence - methods; Neoplasms - diagnosis; Pathology. Cytology. Biochemistry. Spectrometry. Miscellaneous investigative techniques; Spectrophotometry, Infrared - methods; Staining and Labeling - methods; Thiazolidinediones - analysis
• ISSN: 0968-0896; 1464-3391
• DOI: 10.1016/S0968-0896(03)00239-6

Purpose: We have developed infrared fluorescent labeling agents and infrared-ray fluorescence endoscopes to establish a novel diagnostic technique. Since the fluorescence intensity of the initial labeled antibody (ICG-sulfo-OSu-labeled antibody) was not sufficient for practical use, we synthesized indocyanine green acylthiazolidinethione (ICG-ATT), which was expected to label various target molecules having amino groups efficiently. Materials and Methods: To confirm imaging of infrared fluorescence intensity of ICG-ATT- and ICG-sulfo-OSu-labeled anti-MUC1 antibodies, cotton thread was soaked in various concentrations of the antibody solution in 0.1 M PBS, and observed under the epi-illumination infrared fluorescence microscope. Localization and the intensity of infrared fluorescence and DAB coloring was compared in paraffin sections of human gastric mucosa. Results: In the study of cotton threads, both labeled antibodies showed relatively clear infrared fluorescence, and significant difference was not observed between the two antibodies. ICG-ATT-labeled anti-MUC1 antibody produced stronger staining than that by ICG-sulfo-OSu-labeled antibody. Localization pattern of infrared fluorescent staining was in good agreement with that by the conventional method with oxidized DAB staining. Conclusion: ICG-ATT is useful as a fluorescent-labeling agent for diagnosis of microcancers by infrared fluorescence endoscopes. We synthesized indocyanine green acylthiazolidinethione (ICG-ATT), which was expected to label various target molecules having amino groups efficiently. ICG-ATT labeled antibody seems to be useful as a fluorescent-labeling agent for diagnosis of microcancers by infrared fluorescence.