Synthesis and Biodistribution in mice of 99TcmN(PNP5)(DTC)+ Heterocomplexes

In this study, 99TcmN(PNP5)(PODC)+ (PNP5: bis(dimethoxypropylphosphinoethyl)ethoxyethylamine，PODC：N-methoxyethyl dithiocarbamate), 99TcmN(PNP5)(BODC)+(BODC：N-ethoxyethyl dithiocarbamate), 99TcmN(PNP5)(MOPDTC)+ (MOPDTC：N-methoxypropyl dithiocarbamate) and 99TcmN(PNP5)(EOPDTC)+ (EOPDTC： N-ethoxypropyl dithiocarbamate) four new 99Tcm-nitride heterocomplexes were synthesized by ligand exchange reaction. They are lipophilic cations with good stability, and their radiochemical purities are over 90%. Results of biodistribution in mice show that they have different degrees of myocardial uptake and retention, and that the activity of blood, liver, lungs and other non-target tissues washes out rapidly and is mainly eliminated through kidneys. Of four complexes, the heart/blood, heart/lung and heart/liver ratios at 30min of 99TcmN(PNP5)(EOPDTC)+ are 23.75, 3.45, 3.63, in favor of fast cardiac imaging. It could be developed a novel myocardial perfusion imaging agent by structural optimization to improve its myocardial uptake.