In the past few decades, many radiotracers have been developed as drugs for renal imaging as reported previously but the drawback associated with them is the delayed clearance from kidneys. In this study, we have reported the synthesis of newly designed radiotracer 99mTcN-tetrathiocarbamate (99mTcN-TTC) with the highest radiochemical purity of ~ 98% under optimized reaction conditions. Quality control parameters such as the effect of temperature, pH, reaction time, and amount of substrate were studied to achieve optimized reaction yield. The radiotracer was observed to possess the in vitro stability in normal saline (≥ 95%) and plasma protein stability (≥ 85%) up to 6 h, as well as more hydrophilic with a value of log Po/w = − 2.65. The in vivo biodistribution and scintigraphic imaging studies in normal animal models illustrated that the radiotracer 99mTcN-TTC showed rapid accumulation in kidneys (9.6 ± 0.12% ID/g at 5 min and 1.1 ± 0.01% ID/g at 60 min post-injection) with no uptake in other body tissues, as well as fast clearance (≥ 90% within 60 min) via urinary bladder as estimated by GFR study. These results suggested that the newly synthesized radiotracer has the potential to diagnose renal function and could serve as a novel radiotracer for renal imaging.
Graphic abstract
Radiosynthesis of 99mTcN-TTC using facile and easy synthesis approach as confirmed by Radio-HPLC and HR-MS analysis. The novel radiotracers showed excellent renal imaging and clearance within 60 min after intravenous administration.