99Tcm(CO)3-CNRGD的制备及生物学评价

合成了含异腈基团的多肽偶联物（CNRGD），并用［⁹⁹Tc^m(CO)₃(H₂O)₃］⁺标记，得到具有与整合素α_vβ₃受体多结合位点的⁹⁹Tc^m(CO)₃-CNRGD，并对其进行了体内外生物学评价。结果表明，在优化的标记条件下，⁹⁹Tc^m(CO)₃-CNRGD的标记率达到77%，纯化后，标记物放射化学纯度大于96%。体外稳定性实验显示其具有很高的稳定性；脂水分配系数显示其具有较好的脂溶性。正常小鼠体内分布显示，⁹⁹Tc^m(CO)₃-CNRGD在血液中清除较快，主要通过肝肾代谢。荷MCF-7人乳腺癌裸鼠体内分布显示，注射1、4h后，标记物在肿瘤部位的摄取值达(2.38±0.37)%ID/g和(1.57±0.21)%ID/g，瘤/血比分别达0.71±0.09、1.15±0.15，表明该标记物在肿瘤细胞中有一定的摄取和较长的滞留时间。

Preparation of 99Tcm(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 99Tcm(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 99Tcm(CO)3-CNRGD is satisfactory.The partition coefficients of 99Tcm(CO)3-CNRGD indicate that it is a lipophilic compound.The in vivo biodistribution of the radioco...