Synthesis and biodistribution of the 99mTc(CO)3-DEDT complex as a potential new radiopharmaceutical for brain imaging

Abstract

The 99mTc(CO)3(H2O)-DEDT complex was prepared by a two-step procedure involving the preparation of the precursor fac-[99mTc(CO)3(H2O)3]+, followed by the addition of sodium salt of diethyl dithiocarbamate (DEDT). The radiochemical purity (RCP) of the product was over 90% as measured by thin layer chromatography (TLC). No decomposition of the complex at room temperature was observed over a period of 6 hours. Its partition coefficient indicated that it was a lipophilic complex. The electrophoresis results showed the complex was neutral. Biodistribution in mice demonstrated that the complex can penetrate the intact blood-brain barrier (BBB) and the brain uptake (ID%/g) was 4.22 at 5-minute post-injection, suggesting the complex may lead to a further development of the radiopharma ceutical as a brain perfusion tracer.