【摘要】 目的 建立¹⁸⁸ Re标记抗小细胞肺癌单克隆抗体(MAb)2F7的方法,探讨其标记条件。方法 以葡萄糖酸钠为中间螯合剂，用¹⁸⁸ Re标记2F7，β-疏基乙醇法还原MAb。探讨还原剂SnCl₂ 用量、pH值、MAb浓度等对标记反应的影响。上行纸层析法测定标记率及胶体含量。直线回归外推法测定标记MAb的免疫活性分数,并测定其在荷瘤裸鼠体内的生物分布。结果 ¹⁸⁸ Re标记反应的适宜条件为:4.0～8.0g/L SnCl₂ ,0.1mol/L葡萄糖酸钠溶液,0.5～2g/L MAb,pH值5.4～6.8,标记率在2小时后可达90%以上。荷瘤裸鼠体内生物分布测定表明,注射标记2F7 48小时后,瘤/血比约为2.8,72小时后则达3.2。结论 该标记方法操作简便,标记率高,无需在用药前进一步纯化,反应时间短,是较好的¹⁸⁸ Re标记MAb法。

【Abstract】 Purpose To studymonoclonal antibody 2F7 against small cell lung cancer radiolabelling with ¹⁸⁸ Reusing sodium gluconate as chelating agent. Methods Various parameters of the radiolabelling reaction, such as SnCl₂ concentration, pH value, MAb concentration were studied in details, as well as theimmunoactive fraction of labelled MAb 2F7 and its biodistribution in tumor-bearing nudemice. The reduction of MAb disulfide bonds was performed with β-ME. The labelling efficiency of the procedure and the content ofcolloid were determined by paper chromatography. Results The optimal conditions for this ¹⁸⁸ Re labelling reactionincluded 4.0～8.0g/L SnCl₂ in 0.1mol/Lsodium gluconate solution, 0.5～2g/L MAb and pH 5.4～6.8, and the labelling efficiency was over 90% after 2 hours. Thebiodistribution in tumor-bearing nude mice showed that the labelled MAb 2F7 may be ofpotential clinical application value in cancer radioimmunotherapy with the tumor/bloodratio of 2.8 and 3.2 by 48 hours and 72 hours after administration. Conclusions This method of labelling MAb with ¹⁸⁸ Re is convenientand relatively rapid in performance with satisfactory labelling efficiency, and does notneed further purification of the labelled radio-pharmaceutical before administration.

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