^(99m)Tc-C_(50)的生物性能和安全限度实验研究

Experimental study of the biological property and safety limitation of ^(99m)Tc-C_(50)

为评价 2 -亚氨基噻吩盐酸盐 (2 -IT)法标记的抗结肠癌 (CEA)单克隆抗体99mTc -C50 的生物学性能及标记化合物应用的安全性 ,采用 2 -IT法对C50 化学修饰 ,以99mTc -GH转络合法标记C50 。对标记抗体进行免疫活性、稳定性和安全限度的试验 ,并对荷人结肠癌裸鼠进行放射免疫显像。结果表明 ,标记抗体免疫活性为 4 0 .2 %— 73.2 % ,纸层析法测得最佳标记率为 94 .1 % ,胶体含量为 3.8% ,标记后 1 2h内放化纯度均在 90 %以上。标记化合物无热源 ,无毒性 ,荷人结肠癌裸鼠尾静脉注入99mTc -C50 后放射免疫显像显示 ,6h肿瘤区有放射性浓集 ,2 4hT/NT值为 3.4 6—4 .68。表明以 2 -IT法预处理抗CEA单抗能有效地进行99mTc标记 ,对蛋白活性损伤较少 ,标记方法简单 。

Evaluation of the immunological properties and safety of 99m Tc-C 50 CEA McAb labelled by 2-IT was reported. C 50 was modulated chemically by 2-IT and labelled by 99m Tc with stannous reduction. The immunological activity, stability and safety were studied, and radioimmunoimaging were performed in human colon tumor bearing mice. The results showed that the immunological activity, the best labelling rate of chromatography and colloid inclusion were 40.2%-73.2%, 94.1% and 3.8% respectively, and radiochemicl purity maintained over 90% within 12h after labelling. Labelling products was pyogen free and no toxicity was found. Radioactivity was highly accumalated at tumor site of 6h after injection human colon tumor bearing nude mice, T/NT ratio was 3.46-4.68 at 24h after 99m Tc-C 50 injection. All the findings suggested that preconditioning with 2-IT to C 50 can improve labelling of 99m Tc,and minimize the injury of protein. The labelling method is simple and safe, and can be effectively used for clinical study.