Synthesis and biological evaluation of novel 99mTc-oxo and 99mTc-nitrido complexes with phenylalanine dithiocarbamate for tumor imaging

Abstract

In this study, phenylalanine dithiocarbamate (PHEDTC) ligand was successfully synthesized and then radiolabeled with [99mTcO]3+ core and [99mTc≡N]2+ core to produce 99mTcO–PHEDTC and 99mTcN–PHEDTC, respectively. Both complexes were prepared with high radiochemical purity and had good stability. The partition coefficient results showed they were hydrophilic, while 99mTcN–PHEDTC was more hydrophilic than 99mTcO–PHEDTC. The biodistribution study in mice bearing S 180 tumor showed that 99mTcO–PHEDTC and 99mTcN–PHEDTC had high tumor uptake at 2 h post-injection, 1.91 and 1.21, respectively. The good uptake and retention in tumor together with favorable tumor-to-muscle ratios make them promising candidates for further evaluation as potential tumor imaging agents.