title: Role of Fluorophore Charge on the In Vivo Optical Imaging Properties of Near-Infrared Cyanine Dye/Monoclonal Antibody Conjugates.
abstract: Near-infrared (NIR) fluorophores have several advantages over visible-light fluorophores, including superior light penetration in tissue and lower autofluorescence. We recently demonstrated that a new class of NIR cyanine dyes containing a novel C4'-O-alkyl linker exhibit greater chemical stability and excellent optical properties relative to existing C4'-O-aryl variants. We synthesized two NIR cyanine dyes with the same core structure but different indolenine substituents: FNIR-774 bearing four sulfonate groups and FNIR-Z-759 bearing a combination of two sulfonates and two quaternary ammonium cations, resulting in an anionic (-3) or monocationic (+1) charge, respectively. In this study, we compare the in vitro and in vivo optical imaging properties of monoclonal antibody (mAb) conjugates of FNIR-774 and FNIR-Z-759 with panitumumab (pan) at antibody-to-dye ratios of 1:2 or 1:5. Conjugates of both dyes demonstrated similar quenching capacity, stability, and brightness in target cells in vitro. However, FNIR-Z-759 conjugates showed significantly lower background in mice, resulting in higher tumor-to-background ratio. Thus, FNIR-Z-759 conjugates appear to have superior in vivo imaging characteristics compared with FNIR-774 conjugates, especially in the abdominal region, regardless of the dye-mAb ratio. These results suggest that zwitterionic cyanine dyes are a promising class of fluorophores for improving in vivo optical imaging with antibody-NIR dye conjugates.
authors.forename: Kazuhide
authors.initials: K
authors.lastname: Sato
authors.forename: Alexander P
authors.initials: AP
authors.lastname: Gorka
authors.forename: Tadanobu
authors.initials: T
authors.lastname: Nagaya
authors.forename: Megan S
authors.initials: MS
authors.lastname: Michie
authors.forename: Roger R
authors.initials: RR
authors.lastname: Nani
authors.forename: Yuko
authors.initials: Y
authors.lastname: Nakamura
authors.affiliation: Imaging Probe Development Center, National Heart, Lung, and Blood Institute, National Institutes of Health , Rockville, Maryland 20850, United States.
authors.forename: Vince L
authors.initials: VL
authors.lastname: Coble
authors.affiliation: Imaging Probe Development Center, National Heart, Lung, and Blood Institute, National Institutes of Health , Rockville, Maryland 20850, United States.
authors.forename: Olga V
authors.initials: OV
authors.lastname: Vasalatiy
authors.affiliation: Imaging Probe Development Center, National Heart, Lung, and Blood Institute, National Institutes of Health , Rockville, Maryland 20850, United States.
authors.forename: Rolf E
authors.initials: RE
authors.lastname: Swenson
authors.forename: Peter L
authors.initials: PL
authors.lastname: Choyke
authors.forename: Martin J
authors.initials: MJ
authors.lastname: Schnermann
authors.forename: Hisataka
authors.initials: H
authors.lastname: Kobayashi
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000737:chemistry* / Q000493:pharmacokinetics; D002232:Carbocyanines / Q000737:chemistry* / Q000493:pharmacokinetics; D045744:Cell Line, Tumor; D005260:Female; D005456:Fluorescent Dyes / Q000737:chemistry* / Q000493:pharmacokinetics; D006801:Humans; D018796:Immunoconjugates / Q000737:chemistry* / Q000493:pharmacokinetics; D051379:Mice; D008819:Mice, Nude; D008856:Microscopy, Fluorescence; D009369:Neoplasms / Q000175:diagnosis*; D061848:Optical Imaging; D000077544:Panitumumab; D000644:Quaternary Ammonium Compounds / Q000737:chemistry / Q000493:pharmacokinetics; D013451:Sulfonic Acids / Q000737:chemistry / Q000493:pharmacokinetics
chemical_list: D000911:Antibodies, Monoclonal; D002232:Carbocyanines; D005456:Fluorescent Dyes; D018796:Immunoconjugates; D000644:Quaternary Ammonium Compounds; D013451:Sulfonic Acids; D000077544:Panitumumab