1. Imaging Endogenous Bilirubins with Two-Photon Fluorescence of Bilirubin Dimers
- Author
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Yun-Shiuan Leung, Kuo-Chun Tang, Chun-Ta Kung, Chi-Kuang Sun, Dar-Bin Shieh, Medel Manuel L. Zulueta, Shao-Chieh Chen, Min-Huey Chen, Rofearnor P. Obena, Yu-Shing Chen, Tzu-Ming Liu, Yu-Fang Shen, Yu-Ju Chen, Wen-Jeng Lee, Pi-Tai Chou, Hsin-Yi Huang, Ming-Rung Tsai, Fu-Lien Huang, and Chien-Tai Hsieh
- Subjects
Fluorescence-lifetime imaging microscopy ,Carcinoma, Hepatocellular ,Bilirubin ,Photochemistry ,Analytical Chemistry ,law.invention ,chemistry.chemical_compound ,Nuclear magnetic resonance ,law ,Cell Line, Tumor ,Microscopy ,Humans ,neoplasms ,Liver Neoplasms ,Laser ,Fluorescence ,Microscopy, Fluorescence, Multiphoton ,Liver ,Molecular Diagnostic Techniques ,chemistry ,Excited state ,Femtosecond ,Mouth Neoplasms ,Molecular imaging ,Dimerization - Abstract
On the basis of an infrared femtosecond Cr:forsterite laser, we developed a semiquantitative method to analyze the microscopic distribution of bilirubins. Using 1230 nm femtosecond pulses, we selectively excited the two-photon red fluorescence of bilirubin dimers around 660 nm. Autofluorescences from other endogenous fluorophores were greatly suppressed. Using this distinct fluorescence measure, we found that poorly differentiated hepatocellular carcinoma (HCC) tissues on average showed 3.7 times lower concentration of bilirubins than the corresponding nontumor parts. The corresponding fluorescence lifetime measurements indicated that HCC tissues exhibited a longer lifetime (500 ps) than that of nontumor parts (300 ps). Similarly, oral cancer cell lines had longer lifetimes (>330 ps) than those of nontumor ones (250 ps). We anticipate the developed methods of bilirubin molecular imaging to be useful in diagnosing cancers or studying the dynamics of bilirubin metabolisms in live cells.
- Published
- 2015
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