^(99m)Tc标记抗人肝癌单抗Fab片段修饰物在荷人肝癌裸鼠模型中的放射免疫显像

Study on the method of labelling HAb18 McAb Fab fragment modifier with 99m Tc for radioimmunoimaging in nude mice bearing human hepatocellular carcinoma

研究抗人肝细胞癌单克隆抗体Ｆａｂ片段修饰物的９９ｍＴｃ标记方法。用２亚氨基噻吩盐酸盐（ＩＴ）修饰ＨＡｂ１８Ｆａｂ片段。用９９ｍＴｃＧＨ转络合法标记ＩＴＦａｂ，测定标记物的放化纯度及生物活性，进行荷人肝癌裸鼠模型的放射免疫显像。结果：纸层析法测得标记率为５０％～８０％，体外细胞结合法测定免疫活性为３０％～４０％。荷人肝癌裸鼠模型尾静脉注入９９ｍＴｃＩＴＦａｂ后４～８小时，肿瘤区放射性有浓聚，１２～２２小时浓聚最多，Ｔ／ＮＴ值为５１８～７４８。因此，９９ｍＴｃＩＴＦａｂ可特异性浓聚于荷人肝癌裸鼠模型中，可能成为肝癌放射免疫显像的有效显像剂。

PURPOSE To establish a method of labeling anti hepatoma McAb(HAb18) Fab fragment modifier with 99m Tc METHODS HAb18 Fab was modified with 2 iminotholane and labelled with 99m Tc by transchelation from 99m Tc GH Labeling yield, radiochemical purity and immunoreactivity were determined by TLC SG, PC, Sephadex G50 column chromatography and cell binding assay, respectively The nude mice bearing human hepatoma were used for RII RESULTS 50%～80% radiolabeling yield was obtained, immunoreactivity (IR) was 30%～40% Radioimaging results showed that 99m Tc HAb18 McAb Fab concentrated in the tumor tissue 4～6 hours post injection, and the maximum concentration was seen 12～24 hours post injection T/NT value was 5 18～7 48 at 6～8 hours CONCLUSIONS 99m Tc HAb18 McAb Fab can specifically localize in the tumor tissue of nude mice bearing human hepatocellular carcinoma within 24 hours, and this method can be effectively used for labelling McAb Fab fragment with 99m Tc