~(99)Tc~m(CO)_3-BPHRGD的制备及其在荷M21人黑色素瘤裸鼠体内的生物分布

制备了99 Tcm(CO)3-BPHRGD,并进行了荷M21人黑色素瘤裸鼠体内生物学评价。在pH=7、75℃条件下反应30min,99 Tcm(CO)3-BPHRGD的标记率大于80%,纯化后标记物的放化纯度大于98%。体外稳定性实验结果显示,37℃下,标记物在生理盐水、人血清中具有很好的稳定性。荷M21人黑色素瘤裸鼠体内分布显示,注射99 Tcm(CO)3-BPHRGD后0.5、1、2、4h,标记物的瘤/血比分别为0.70±0.45、0.87±0.05、1.10±0.19、1.68±0.04。随着时间的延长,靶与非靶的放射性摄取比(T/NT)增大,表明该标记物在肿瘤细胞中的清除速度慢于其他组织。通过进一步结构修饰,改变其体内代谢途径及药代动力学性质,99 Tcm(CO)3-BPHRGD非常有希望成为一种新型肿瘤显像剂。

Preparation of99Tcm(CO)3-BPHRGD and Its Biodistribution in Nude Mice Bearing M21 Human Melanoma Tumor

The ⁹⁹Tc^m(CO)₃-BPHRGD was prepared, and in-vivo biological evaluations in nude mice bearing M21 human melanoma tumor were completed. The labeling yield of ⁹⁹Tc^m(CO)₃-BPHRGD is more than 80% under optimal conditions (pH=7, reacting at 75 ℃ for 30 min), and the radiochemical purity is more than 98% after purification. The in-vitro stability experiments show that the radiolabeled compound has good stability in normal saline and human serum under 37 ℃. The biodistribution of ⁹⁹Tc^m(CO)₃-BPHRGD in nude mice bearing M21 human melanoma tumor shows that the ratio of tumor/blood is 0.70±0.45, 0.87±0.05, 1.10±0.19 and 1.68±0.04 at 0.5, 1, 2 and 4 h respectively. The ratio of T/NT increases with time. This indicates that the clearance rate of this radiolebeled compound in tumor is slower than in other tissues. Through the further structural modification to change metabolic pathways and pharmacokinetic properties, it is very promising as a new tumor imaging agent.