Hybrid lymph node imaging using 64Cu-labeled mannose-conjugated human serum albumin with and without indocyanine green. Issue 10 (October 2015)

• Record Type: Journal Article
• Authors: Kang, Choong Mo; An, Gwang Il; Choe, Yearn Seong
• Is Part Of: Nuclear medicine communications. Volume 36:Issue 10(2015:Oct.)
• Publication Date: 2015-10
• Subjects: Nuclear medicine -- Periodicals; 616.07575
• DOI: 10.1097/MNM.0000000000000353
• Languages: English
• ISSNs: 0143-3636

Abstract

<abstract> <title> <x xml:space="preserve">Abstract</x> </title> <sec> <title>Objective</title> <p>Human serum albumin (HSA), which has 58 Lys residues, one Cys residue, and indocyanine green (ICG) adsorption sites, can be used as a multifunctional platform for the development of hybrid imaging probes. In this study, we prepared <sup>64</sup>Cu-labeled mannose-conjugated HSA with and without ICG ([<sup>64</sup>Cu]<bold>1</bold>-ICG and [<sup>64</sup>Cu]<bold>1</bold>, respectively) and compared hybrid PET/near-infrared fluorescence (NIRF) imaging with positron emission tomography (PET)/Cerenkov luminescence (CL) imaging of lymph nodes (LNs).</p> </sec> <sec> <title>Materials and methods</title> <p>1, 4, 7, 10-Tetraazacyclododecane-<italic>N</italic>, <italic>N</italic>′, <italic>N</italic>′′, <italic>N</italic>′′′-tetraacetic acid (DOTA)/mannose-conjugated HSA (<bold>1</bold>) was synthesized by conjugating mannose molecules to Lys residues and a DOTA molecule to a Cys residue of HSA. Compound <bold>1</bold> was then labeled with <sup>64</sup>Cu ([<sup>64</sup>Cu]<bold>1</bold>), and the resulting [<sup>64</sup>Cu]<bold>1</bold> was adsorbed with ICG ([<sup>64</sup>Cu]<bold>1</bold>-ICG). PET/NIRF or PET/CL imaging and subsequent biodistribution studies were performed in ICR mice after injection of the probes into the foot pads.</p> </sec> <sec> <title>Results</title> <p>The numbers of mannose and DOTA molecules conjugated to HSA were 7.17±0.49 and 0.95±0.18, respectively. The site-specific conjugation of one DOTA molecule to HSA was sufficient for <sup>64</sup>Cu-labeling with high efficiency (96.0±1.1%). PET/NIRF and PET/CL imaging and subsequent biodistribution studies demonstrated that the probes were avidly taken up by the popliteal LNs (PO), with a slightly higher uptake ratio of the PO to the lumbar LNs by [<sup>64</sup>Cu]<bold>1</bold>.</p> </sec> <sec> <title>Conclusion</title> <p>In-vivo studies suggest that [<sup>64</sup>Cu]<bold>1</bold> has more specific and selective binding to mannose receptors in the PO than [<sup>64</sup>Cu]<bold>1</bold>-ICG.</p> </sec> </abstract>