Radiosynthesis and preliminary biological evaluation of 99mTc-labeled 2-methyl-2-pentylmalonic acid as an apoptosis imaging agent

Apoptosis is one of the fundamental phenomena behind successful radiation and chemotherapy treatments. Non-invasive imaging of apoptosis can offer an early diagnosis of disease and the true efficiency of an ongoing treatment procedure. The present study describes an attempt to develop Tc-99m-labeled 2-methyl-2-pentylmalonic acid ([Tc-99m] 8) as a new SPECT based apoptosis imaging agent. An optimized chemical and radiosynthesis procedure provided desired product [Tc-99m] 8 with high radiochemical yield (84%, n = 3) and radiochemical purity (> 99%) as determined by radio HPLC. Biodistribution data indicated that the radiotracer has a rapid clearance from blood and other background tissues. High testes accumulation confirmed the ability of the radiotracer to detect testicular apoptosis in mice.