title: Noninvasive real-time fluorescence imaging of the lymphatic uptake of BSA-IRDye 680 conjugate administered subcutaneously in mice.
abstract: The goal of our studies was to determine lymphatic uptake of bovine serum albumin (BSA) using real-time noninvasive fluorescence imaging. BSA labeled with near-infrared dye (IRDye) 680 was used as a model protein-dye conjugate. The conjugation of BSA with IRDye 680 was confirmed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Size-exclusion high-performance liquid chromatography and SDS-PAGE demonstrated that the IRDye 680-labeled BSA conjugate in the lymph node (LN) homogenate samples was stable at physiological temperature (37°C) for at least 5 days. Whole-body noninvasive optical imaging of hairless SKH-1 mice was performed after subcutaneous (s.c.) injection (dose = 0.1 mg/kg) into the front footpad. Noninvasive fluorescence imaging demonstrated that BSA-IRDye 680 conjugates were dynamically taken up by the lymphatic system, accumulated in the axillary LNs and then cleared, indicating that lymphatic transport plays a role in the absorption of BSA. Ex vivo tissue imaging of LN homogenates provided confirmatory data with respect to the uptake of fluorescent-labeled BSA determined by in vivo imaging. Noninvasive real-time imaging of LNs provides a novel tool for evaluating uptake and accumulation of fluorescent-labeled proteins by the lymphatic system after s.c. injection in a mouse model.
authors.affiliation: Department of Pharmaceutical Sciences, University at Buffalo, State University of New York, Amherst, New York 14260, USA.
authors.forename: Fang
authors.initials: F
authors.lastname: Wu
authors.forename: Suraj G
authors.initials: SG
authors.lastname: Bhansali
authors.forename: Mitalee
authors.initials: M
authors.lastname: Tamhane
authors.forename: Rajiv
authors.initials: R
authors.lastname: Kumar
authors.forename: Lisa A
authors.initials: LA
authors.lastname: Vathy
authors.forename: Hong
authors.initials: H
authors.lastname: Ding
authors.forename: Ken-Tye
authors.initials: KT
authors.lastname: Yong
authors.forename: Earl J
authors.initials: EJ
authors.lastname: Bergey
authors.forename: Paras N
authors.initials: PN
authors.lastname: Prasad
authors.forename: Marilyn E
authors.initials: ME
authors.lastname: Morris
mesh_terms: D000818:Animals; D002850:Chromatography, Gel; D002851:Chromatography, High Pressure Liquid; D004591:Electrophoresis, Polyacrylamide Gel; D005453:Fluorescence; D005456:Fluorescent Dyes / Q000737:chemistry / Q000378:metabolism*; D007279:Injections, Subcutaneous; D042601:Lymphatic Vessels / Q000378:metabolism*; D051379:Mice; D012710:Serum Albumin, Bovine / Q000737:chemistry / Q000378:metabolism*
chemical_list: D005456:Fluorescent Dyes; D012710:Serum Albumin, Bovine