新型骨显像剂99Tcm-HBIDP的制备与初步生物学性质

在SnCl2.2H2O存在下,用Na 99 TcmO4标记1-羟基-2-(1-丁基-1H-咪唑-2-基)亚乙基-1,1-双膦酸(HBIDP)。研究了99 Tc m-HBIDP的最优标记条件、理化性质及其在正常小鼠体内分布。结果表明,当pH=6、m(SnCl2.2H2O)=100μg、m(HBIDP)=5mg、A(99 TcmO4-)=55.5MBq、室温反应15min时,99 Tcm-HBIDP的标记率大于95%。99 Tcm-HBIDP在pH为7.0和7.4时,脂水分配系数lg P分别为-2.17和-2.28。99 Tcm-HBIDP的血浆蛋白结合率为(31.41±1.25)%。99 Tcm-HBIDP具有良好的体外稳定性。动物分布实验显示:99 Tcm-HBIDP在骨组织中有较高摄取,并能保持较长时间;其在软组织中的摄取相对较低,并能较快的清除。此外,99 Tcm-HBIDP较99 Tcm-ZL在心、肝、脾等器官组织中的摄取低。99 Tcm-HBIDP有望成为新型骨显像剂。

Preparation and Biological Study on a Novel Bone Imaging Agent 99Tcm-HBIDP

To obtain a maximum radiolabeling yield,the labeling parameters for 99Tcm-HBIDP were optimized.Chemical and physical properties and biodistribution studies in mice for 99Tcm-HBIDP were performed.The optical labeling parameters are found as follows:pH=6,m(SnCl2·2H2O)=100 μg,m(HBIDP)=5 mg,A(99TcmO-4)=55.5 MBq at room temperature for 15 min and the radiochemical purity is more than 95% and it is stable within 6 h in vitro at room temperature.The octanol-water partition coefficients of 99Tcm-HBIDP(lg P) are-2.17 and-2.28 at the pH value of 7.0 and 7.4,respectively.The plasma protein binding ratio of 99Tcm-HBIDP is(31.41±1.25)%.In the biodistribution studies,99Tcm-HBIDP exhibits a relatively high uptake in bone and much lower uptake in soft tissues and shows rapid clearance from soft tissues.Besides,the uptake of 99Tcm-HBIDP in heart,liver and spleen is much lower than that of 99Tcm-ZL.These preliminary studies indicate that 99Tcm-HBIDP has significant potential as a novel bone imaging agent.