title: Preclinical evaluation of a novel cyanine dye for tumor imaging with in vivo photoacoustic imaging.
abstract: Photoacoustic imaging (PA imaging or PAI) has shown great promise in the detection and monitoring of cancer. Although nanocarrier-based contrast agents have been studied for use in PAI, small molecule contrast agents are required due to their ease of preparation, costeffectiveness, and low toxicity. Here, we evaluated the usefulness of a novel cyanine dye IC7-1-Bu as a PAI contrast agent without conjugated targeting moieties for in vivo tumor imaging in a mice model. Basic PA characteristics of IC7-1-Bu were compared with indocyanine green (ICG), a Food and Drug Administration approved dye, in an aqueous solution. We evaluated the tumor accumulation profile of IC7-1-Bu and ICG by in vivo fluorescence imaging. In vivo PAI was then performed with a photoacoustic tomography system 24 and 48 h after intravenous injection of IC7-1-Bu into tumor bearing mice. IC7-1-Bu showed about a 2.3-fold higher PA signal in aqueous solution compared with that of ICG. Unlike ICG, IC7-1-Bu showed high tumor fluorescence after intravenous injection. In vivo PAI provided a tumor to background PA signal ratio of approximately 2.5 after intravenous injection of IC7-1-Bu. These results indicate that IC7-1-Bu is a promising PAI contrast agent for cancer imaging without conjugation of targeting moieties.
authors.affiliation: Kyoto University, Graduate School of Pharmaceutical Sciences, Department of Patho-Functional Bioanalysis, 46-29 Yoshida Shimoadachi-cho, Sakyo-ku, Kyoto 606-8501, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Temma
authors.affiliation: Kyoto University, Graduate School of Pharmaceutical Sciences, Department of Patho-Functional Bioanalysis, 46-29 Yoshida Shimoadachi-cho, Sakyo-ku, Kyoto 606-8501, Japan.
authors.forename: Satoru
authors.initials: S
authors.lastname: Onoe
authors.affiliation: Kyoto University, Graduate School of Pharmaceutical Sciences, Department of Patho-Functional Bioanalysis, 46-29 Yoshida Shimoadachi-cho, Sakyo-ku, Kyoto 606-8501, JapanbCanon Inc., Medical Imaging Project, Corporate R&D Headquarters, 3-30-2 Shimomaruko, O.
authors.forename: Kengo
authors.initials: K
authors.lastname: Kanazaki
authors.affiliation: Kyoto University, Graduate School of Pharmaceutical Sciences, Department of Patho-Functional Bioanalysis, 46-29 Yoshida Shimoadachi-cho, Sakyo-ku, Kyoto 606-8501, Japan.
authors.forename: Masahiro
authors.initials: M
authors.lastname: Ono
authors.affiliation: Kyoto University, Graduate School of Pharmaceutical Sciences, Department of Patho-Functional Bioanalysis, 46-29 Yoshida Shimoadachi-cho, Sakyo-ku, Kyoto 606-8501, Japan.
authors.forename: Hideo
authors.initials: H
authors.lastname: Saji
mesh_terms: D000818:Animals; D004396:Coloring Agents / Q000737:chemistry*; D003287:Contrast Media / Q000737:chemistry*; D003952:Diagnostic Imaging / Q000379:methods*; D005260:Female; D006367:HeLa Cells; D006801:Humans; D007208:Indocyanine Green; D007211:Indoles / Q000737:chemistry*; D051379:Mice; D008819:Mice, Nude; D009369:Neoplasms / Q000378:metabolism / Q000473:pathology*; D061088:Photoacoustic Techniques / Q000379:methods*
chemical_list: D004396:Coloring Agents; D003287:Contrast Media; D007211:Indoles; D007208:Indocyanine Green