Studies toward the biological efficacy of (99m)Tc-labeled dextran-cysteine-mannose ([(99m)Tc(CO)(3)]DCM20) for sentinel lymph node detection.
Abstract The aim of this work was to determine the potential of (99m)Tc carbonyl-labeled dextran-cysteine-mannose (DCM20) as a mannose receptor targeting agent for sentinel lymph node (SLN) detection using biological in vitro and in vivo assays. (99m)Tc labeling of the previously reported DCM20 ligand was carried out via the [(99m)Tc(H(2)O)(3)(CO)(3)](+) synthon. High-performance liquid chromatography (HPLC) showed >99% radiolabeling yield using 50 μg of the ligand. In vitro cell uptake studies performed in RAW 264.7 mouse macrophage precursor cells showed a specific uptake of the preparation. In vivo distribution and scintigraphic imaging were studied in the Wistar rat model. Appreciable uptake and retention of the radiolabeled conjugate was observed in the SLN (4.53%±0.29% at 15 minutes and 3.35%±0.72% at 180 minutes postinjection [p.i.] for 2.5 μg/animal) with a high percentage of popliteal extraction (≥98% at all time points studied), and negligible activity in other nodes as well as blood and nontarget organs. The radiolabeled conjugate also exhibited rapid clearance from the injection site (from ~39.1% clearance at 15 minutes to ~56.5% clearance at 180 minutes p.i.), comparable to current clinically employed agents for SLN detection. These results suggest that [(99m)Tc(CO)(3)]DCM20 could be a potentially useful receptor-based SLN detection agent.
Radiopharmaceuticals Division, Bhabha Atomic Research Centre, Mumbai, India.
Suresh
S
Subramanian
Usha
U
Pandey
Minas
M
Papadopoulos
Ioannis
I
Pirmettis
Meera
M
Venkatesh
Grace
G
Samuel
D000818:Animals; D002460:Cell Line; D004195:Disease Models, Animal; D005260:Female; D037181:Lectins, C-Type / Q000378:metabolism; D008198:Lymph Nodes / Q000000981:diagnostic imaging*; D008264:Macrophages / Q000000981:diagnostic imaging / Q000378:metabolism; D000090323:Mannose Receptor; D037241:Mannose-Binding Lectins / Q000378:metabolism; D051379:Mice; D015609:Organotechnetium Compounds / Q000737:chemistry / Q000493:pharmacokinetics; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals; D051381:Rats; D017208:Rats, Wistar; D011956:Receptors, Cell Surface / Q000378:metabolism; D021701:Sentinel Lymph Node Biopsy / Q000379:methods*; D013667:Technetium
D037181:Lectins, C-Type; D000090323:Mannose Receptor; D037241:Mannose-Binding Lectins; D015609:Organotechnetium Compounds; D019275:Radiopharmaceuticals; D011956:Receptors, Cell Surface; D013667:Technetium