title: Albumin-binding domain conjugate for near-infrared fluorescence lymphatic imaging.
abstract: OBJECTIVE
  The aim of this study was to develop and characterize a novel peptide imaging agent for noninvasive near-infrared fluorescence imaging of protein transport by the lymphatics. An imaging agent consisting of a cyclic albumin-binding domain (cABD) peptide, with sequence, Arg-Leu-Ile-Glu-Asp-Ile-Cys-Leu-Pro-Arg-Trp-Gly-Cys-Leu-Trp-Glu-Asp-Asp-Lys, was conjugated to a near-infrared fluorophore, IRDye800CW, allowing for enhanced vascular uptake, retention, and fluorescence imaging.
  
  
  METHODS
  Characterization of the cABD-IRDye800 peptide conjugate was performed using fluorescence spectroscopy to assess optical properties and SDS-PAGE and Biacore binding assays to determine binding affinity and specificity. Fluorescence imaging of normal C57BL/6 mice was conducted to monitor lymphatic uptake and retention.
  
  
  RESULTS
  cABD-IRDye800 exhibited approximately six times greater fluorescent yield and greater stability than indocyanine green, an agent previously used in humans to image lymphatic vasculature. The agent exhibited affinity for albumin with IC(50) and Kd in the nanomolar range and demonstrated superior retention characteristics within mouse lymphatics when compared with IRDye800CW.
  
  
  CONCLUSIONS
  cABD-IRDye800 has utility for assessing lymphatic function in mouse models of human lymphatic disease and the potential for use in clinical diagnostic imaging of the lymphatic vasculature.
authors.affiliation: The Center for Molecular Imaging, The Brown Foundation Institute of Molecular Medicine, University of Texas Health Science Center, Houston, TX 77030, USA.
authors.forename: Cynthia A
authors.initials: CA
authors.lastname: Davies-Venn
authors.forename: Bonnie
authors.initials: B
authors.lastname: Angermiller
authors.forename: Nathaniel
authors.initials: N
authors.lastname: Wilganowski
authors.forename: Pradip
authors.initials: P
authors.lastname: Ghosh
authors.forename: Barrett R
authors.initials: BR
authors.lastname: Harvey
authors.forename: Grace
authors.initials: G
authors.lastname: Wu
authors.forename: Sunkuk
authors.initials: S
authors.lastname: Kwon
authors.forename: Melissa B
authors.initials: MB
authors.lastname: Aldrich
authors.forename: Eva M
authors.initials: EM
authors.lastname: Sevick-Muraca
mesh_terms: D000418:Albumins / Q000378:metabolism*; D000818:Animals; D001665:Binding Sites; D004591:Electrophoresis, Polyacrylamide Gel; D005456:Fluorescent Dyes / Q000737:chemistry* / Q000378:metabolism / Q000493:pharmacokinetics; D006801:Humans; D007208:Indocyanine Green; D042601:Lymphatic Vessels / Q000033:anatomy & histology* / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D010455:Peptides / Q000737:chemistry / Q000378:metabolism; D011485:Protein Binding; D013050:Spectrometry, Fluorescence / Q000379:methods*; D019265:Spectroscopy, Near-Infrared / Q000379:methods*
chemical_list: D000418:Albumins; D005456:Fluorescent Dyes; D010455:Peptides; D007208:Indocyanine Green