Evaluation of novel cationic 99mTc-nitrido complexes as radiopharmaceuticals for heart imaging: improving liver clearance with crown ether groups

摘要: Abstract This report describes the evaluation of a series novel cationic 99m Tc-nitrido complexes, [ TcN(DTC)(PNP)] + (DTC=crown ether-containing dithiocarbamates; PNP=bisphosphine), as potential radiotracers for myocardial perfusion imaging. Synthesis complexes was accomplished in two steps according to literature methods. Biodistribution studies were performed rats. Planar images Sprague-Dawley rats administered with 15±2 MBq Tc radiotracer obtained using PhoGama large field-of-view Anger camera. Samples from both urine and feces analyzed by reversed-phase radio-HPLC method. Results biodistribution showed that most have high initial heart uptake long retention. They also show rapid clearance liver lungs. Cationic TcN(L2)(L6)] TcN(L4)(L6)] heart/liver ratios four five times better than Tc-sestamibi due their much faster clearance. Their ratio are comparable TcN-DBODC5 within experimental error. These findings been confirmed results imaging studies. Radio-HPLC analysis samples indicated there very little metabolism under anesthesia. The key finding this study is lipophilicity remains important factor affecting target-to-background (T/B) ratios. Crown ethers useful functional groups improve complexes. It combination appropriate DTCs bisphosphines fast at same time. suggests they might be used obtain clinically early 30 min postinjection. promising candidates further more extensive preclinical animal models.