Synthesis and In vitro Evaluation of ^(99m)Tc-diglucosediethylenetriamine (DGTA) as a Potential Tumor Imaging Agent

Using a single step chemical synthesis, we synthesized the potential tumor imaging agent ^(99m)Tc-diglucosediethylenetriamine (DGTA) from diethylenetriamine and natural D-glucose. 10 min Incubation of 10 mg of precursor with 50 μg of SnCl_2·2H_2O at room temperature yielded over 95% of ^(99m)Tc labeling. The stability for 6 hours in saline or human plasma was over 90%. In vitro tumor cell uptake assays using the SNU-C5 and 9 L cell lines showed that, in 0-400 mg/dL glucose medium, cell uptake of ^(99m)Tc-DGTA was 1.5-8 times higher than that of [^18F]FDG. Moreover, [^18F]FDG uptake was dependent on glucose concentration in the medium,whereas cellular uptake of ^(99m)Tc-DGTA was not dependent on glucose concentration, suggesting that the two compounds have different uptake mechanisms by tumor cells.