Colchicine is a cytotoxic bioactive alkaloid that exhibits its action by microtubular binding. With an aim to develop a tumor targeted radio-therapeutic agent, colchicine has been functionalized to trimethylcolchicinic acid and conjugated to the isothiocyanato derivative of DOTA (1,4,7,10-tetraaza cyclododecane tetracetic acid). DOTA coupled colchicine was radiolabeled with 90Y, one of the most commonly used therapeutic radioisotope. Complexation of 200 µg of the conjugate with 90Y was carried out at pH 4.5 with an incubation time of 45 min at 70°C. Complexation yield of 90Y-DOTA-NCS-colchicine was confirmed to be >98% using C-18 reverse phase HPLC system. 90Y-colchicine complex could be differentiated from 90Y-p-NCS-benzyl-DOTA on the basis of difference in their retention times 8 and 4 min, respectively in a standardized HPLC system. Biodistribution studies in Swiss mice fibrosarcoma tumor model showed an uptake of ∼0.8% ID/g tumor at 3 h.p.i. that was retained till 24 h.p.i. 90Y-DOTA-NCS-colchicine complex showed excellent pharmacokinetics with major portion of the radioactivity being excreted out within 3 h.p.i. and no accumulation of radioactivity in vital organs. Copyright © 2006 John Wiley & Sons, Ltd.
秋水仙碱是一种细胞毒性
生物活性
生物碱,通过微管结合发挥作用。为了开发一种肿瘤靶向放射治疗剂,
秋水仙碱被功能化为三甲基秋
水仙酸,并与DOTA(1,4,7,10-四氮
环十二烷四乙酸)的异
硫氰酸酯衍
生物结合。DOTA偶联的
秋水仙碱被放射性标记为90Y,这是最常用的治疗放射性同位素之一。在pH 4.5、70°C下孵育45分钟的条件下,200 µg的偶联物与90Y的络合反应。使用C-18反相HPLC系统确认90Y-DOTA-
NCS-colchicine的络合产率>98%。在标准HPLC系统中,90Y-colchicine络合物与90Y-p-
NCS-苄基-DOTA基于它们的保留时间差异(分别为8分钟和4分钟)进行区分。在瑞士小鼠纤维肉瘤肿瘤模型中的
生物分布研究显示,在3小时时肿瘤摄取约为0.8% ID/g,并在24小时时保持不变。90Y-DOTA-
NCS-colchicine络合物显示出优异的药代动力学特性,大部分放射性在3小时时排出,并且没有在重要器官中积累放射性。版权所有 © 2006 John Wiley & Sons, Ltd.