摘要
目的 研究99Tcm 抗人膀胱癌人 鼠嵌合抗体ch BDI对膀胱癌细胞的体外结合性能、在荷人膀胱癌裸鼠中的体内分布及对肿瘤的靶向定位性能。方法 用改进的Schwarz方法进行99Tcm 标记 ,经SephadexG 5 0柱分离纯化。用纸层析法测定标记率与放化纯 ;用Lindmo的方法测定免疫活性分数 ;用Scatchard作图法求得亲和常数。荷人膀胱癌裸鼠静脉注射99Tcm ch BDI 11.1MBq(30 μg) ,分别于 2、6、2 0及 2 4h行放射免疫显像。用感兴趣区 (ROI)技术获得全身和肿瘤放射性计数及肿瘤与对侧正常组织 (T NT)的放射性比值。 2 4h显像后处死裸鼠 ,测定体内放射性分布 ,计算每克组织百分注射剂量率 (%ID g)及T NT比值。结果 99Tcm ch BDI标记率为 (6 6 .5± 7.3) % ,放化纯 >90 % ,免疫活性分数为 76 % ,亲和常数为 3.5 6× 10 9L mol。荷人膀胱癌裸鼠放射免疫显像结果示 ,静脉注射后 6h肿瘤显影清晰 ,随时间延长更清晰。全身放射性计数随时间延长迅速降低 ,肿瘤放射性计数下降缓慢 ,T NT比值随时间增高。荷瘤裸鼠体内分布结果示 ,静脉注射后 2 4h肿瘤 %ID g为 17.4 ,除肾脏外 ,肿瘤与其他正常组织有很高的T NT比值 ,与脑、肌肉、小肠壁、骨骼及心壁的T NT比值分别为 136 .0、5 5 .1、39.3、2 9.7及 2 7 9。结论 ch BDI具有良?
Objective To study the in vitro immunoreactivity and in vivo tissue distribution, tumor targeting property of anti-human bladder tumor human-murine chimeric antibody (ch-BDI) labeled with 99Tcm and to investigate its possibility for being used in guiding diagnosis and guiding therapy of bladder cancer. Methods The ch-BDI was labeled with 99Tcm by improved Schwarz method and the labeled antibody was purified by Sephadex G-50. Labeling yield and radiochemical purity were measured by paper chromatography. The immunoreactive fraction and association constant (K a) were measured by Lindmo method and Scatchard analysis, respectively. 11.1 MBq(30 μg) 99Tcm-ch-BDI was intravenously injected into nude mice bearing human bladder cancer xenografts in the right thigh and radioimmunoimaging (RII) was performed 2, 6, 20 and 24 h postinjection. The images were processed by region of interest (ROI) method to acquire the counts of whole body and the tumor and the counts ratios of tumor to contralateral normal tissue or to tissues of other non-tumor bearing organs. The mice were killed after 24 h postinjection imaging and tissue distribution was measured. %ID/g and target to nontarget (T/NT) ratios were calculated. Results The labeling yield and radiochemical purity of 99Tcm-ch-BDI were (66.5±7.3)% and >90%,respectively. The immunoreactive fraction was 76% and K a was 3.56×109 L/mol. RII showed that the tumor was clearly visualized 6 h postinjection and becoming clearer along with time prolonging. The radioactivity of whole body decreased rapidly with time, whereas the radioactivity of the tumor decreased slowly. The T/NT ratios was increased with time. Biodistribution results showed that tumor uptake was 17.4 %ID/g 24 h postinjection. T/NT ratios were very high except for the kidney. T/NT ratios for brain, muscle, intestinal wall, bone and heart wall were 136.0, 55.1, 39.3, 29.7 and 27.9, respectively. Conclusion 99Tcm-ch-BDI exhibits excellent immunoreactivity and tumor targeting property and has potential applications in guiding diagnosis and guiding therapy of bladder cancer.
出处
《中华核医学杂志》
CAS
CSCD
北大核心
2003年第4期212-214,共3页
Chinese Journal of Nuclear Medicine
