Preparation of ⁹⁹Tc^m(CO)₃-CNRGD and Its Biologic Evaluation

A new radioconjugate with three cyclic RGD was prepared, and in vitro and in vivo evaluation of this conjugate was studied. The results show that the radiolabeled yield of ⁹⁹Tc^m(CO)₃-CNRGD reaches to 77% under optimum conditions and the radiochemical purity is more than 96% after purification with a C-18 Sep-Pak Cartridge. The in vitro stability of ⁹⁹Tc^m(CO)₃-CNRGD is satisfactory. The partition coefficients of ⁹⁹Tc^m(CO)₃-CNRGD indicate that it is a lipophilic compound. The in vivo biodistribution of the radioconjugate in normal mice shows rapid clearance from blood and excretion mainly through hepatobiliary and renal systems. The results in nude mice bearing MCF-7 breast tumor xenografts show that the radioconjugate has moderately tumor uptake and long tumor retention time.