^(99m)Tc(Ⅳ)标记双膦酸配合物的制备及其在动物体内的骨显像性能

Preparation and in vivo Bone Imaging Properties of ^(99m)Tc(Ⅳ)-Labeled Diphosphonic Acid Complex

以2-乙基咪唑、5-溴戊酸乙酯和PCl3为原料,合成了一种唑来膦酸衍生物:1-羟基-5-(2-乙基-1H-咪唑-1-基)戊烷-1,1-双膦酸(EIPeDP),将其与放射性元素99mTc(Ⅳ)进行标记形成配合物,研究了EIPeDP用量和反应体系pH值对标记率的影响。结果表明,当pH值为5～6、EIPeDP为5 mg、SnCl2.2H2O为100μg和Na99mTcO4为92.5 MBq时,可获得满意的标记率和放化纯(均大于97%)。标记物99mTc-EIPeDP具有良好的体外稳定性。动物体内实验表明,兔经注射99mTc-EIPeDP 1 h后获得的骨显像图质量明显优于99mTc-ZL和99mTc-MDP。表明99mTc-EIPeDP是一种制备简便、稳定性好和骨显像性能优异的新型放射显像剂。

A zoledronic acid derivative, 1-hydroxy-5-（2-ethyl-lH-irnidazol-l-yl） pentane-1, l-diphosphonic acid（EIPeDP）, was synthesized using 2-ethylimidazole, 5-bromo valeric acid ethyl ester and PC13 as the starting material and further labeled with 99mTc. The influence of the amount of EIPeDP and the pH value of the reaction system on the labeling yield of 99mTc-EIPeDP has been studied. Satisfactory radiolabelling yield （RLY） and the radiochemical purity（RCP） （over 97% ） were obtained when the pH was 5 -6 and the amount of EIPeDP, SnC12 ~ 2H20 and Na99~ TcO4 were 5 mg, 100 I-~g and 92. 5 MBq, respectively. The radiolabeled complex was very stable in vitro. In vivo SPECT bone imaging of rabbit showed that a clearer image can be obtained from 99mTc-EIPeDP at 1 h post injection, which is superior to 99mTc-ZL and 99mTc-MDP. These results showed that 99mTc-EIPeDP is a potential bone imaging agent with advantages of simple preparation, good stabihty and superior bone imaging characteristics.