一种新型骨关节软骨显像剂^(99m)TC-硫酸软骨素的制备及动物实验

A New Radiopharmaceutical for Osteoarthral Cartilage Imaging:Preparation and Animals Experiment of ^(99m)Tc-CS

本研究的目的是制备一种新的放射性药物,探讨其作为骨软骨显像剂的可能性。该方法采用亚锡还原法标记硫酸软骨素(Chondroitin sulfate,CS),其标记率及放射化学纯度分别为79.30%±1.72%和90.12%±1.23%。动态观察99mTc-CS在动物体内不同时相的生物学资料,表明该显像剂从血液清除快,主要经肾脏排泄,亲软骨组织特性较好。建立兔骨关节炎模型,于耳缘静脉注射99mTc-CS后5h进行静态影像,得到的显像图片清晰,病灶摄取显像剂明显增多,利用勾画感兴趣区技术计算病变关节与对侧正常组织(T/NT)的放射性计数比值为3.0±0.6(P<0.05)。结果表明99mTc-CS的标记方法简便,亲软骨组织性能良好,有待发展成为一种新的骨关节软骨显像剂。

The objective of this research work is to prepare a new and reliable radiopharmaceutical for osteoarthral cartilage imaging. Chondroitin sulfate（CS） was labeled directly with ^99mTc by ＂pretinning＂ method,the labeling efficiency was 79.30%±1.72 % and radiochemical purity was 90.12% ±1.23 % after filtration by use of asepsis filter membrane. The biodistribution of ^99mTc-CS was studied at 10,30 min and 1,2,3,4,5,6,7,8,9 h respectively after caudal vein injection in normal mice,which showed that the radiolabeled product was washed out from blood quickly, and it was mainly excreted through kidney, but ^99mTc-CS had distinctive characteristic of philo- cartilage. Scintigraphy of ^99mTe-CS was performed on the rabbit with ostarthritis at 5h after intravenous injection; the scintigram was clear,and the focus showed increased radiopharmaeeutical uptake. The radioactivity ratio of the injured/uninjured side （T/NT）calculated over the region of interest （ROD was 3.0±0.6（P〈0. 05）. These results indicate that ^99mTc-CS is an easily prepared compound with the characteristic of high philo-cartilage and it may be a new ideal cartilage imaging agent.