【摘要】 目的制备高纯度放射性125I标记的酪氨酸聚乙二醇化胸腺素α1(Tyr-PEG-TA1)用于动物药代动力学研究。方法改良Iodogen法进行125I标记。Ziptip头监测标记反应进程以优化反应条件。采用Sephadex G50与Sephadex G10两步凝胶层析法对标记混合物进行纯化。利用酶免疫分析(EIA)方法鉴定PEG-TA1增加酪氨酸残基前后以及Tyr-PEG-TA1经125I标记前后免疫学活性的变化。结果PEG-TA1增加酪氨酸残基前后以及Tyr-PEG-TA1经125I标记前后免疫活性均无明显变化,纯化后的标记产物放化纯度为95.9%,放射性比活度为39.4Bq/ng。结论成功地制备了放化纯度和放射性比活度均满足药代动力学研究的125I-Tyr-PEG-TA1。更多还原

【Abstract】 Objective To prepare a highly purified 125 I -pegylated thymosin α1 （PEG-TA1） with satisfied bioactivity for using in the distribution and excretion study in animals. Methods Tyr-PEG-TA1 was iodinated by means of Iodogen method. The ZipTip pipette tips were utilized to monitor the reaction process for the optimization of reaction conditions. A two-step gel filtration chromatography with Sephadex G50 followed by Sephadex G10 was applied to purify the labelled products. The bioactivity assay of PEG-TA1, Tyr-PEG-TA1 and 125 I -Tyr-PEG-TA1 were performed by an enzyme immunoassay （EIA） method. Results The optimum condition of labelling reaction was: shaking for 20 min at 25℃ in 0.1 mol/L phosphate buffer （0.1mol/L NaCl） with the pH value of 7.0. Slight but no significant difference of bioactivity among the PEG-TA1, Tyr-PEG-TA1 and the 125 I -Tyr-PEG-TA1 was observed. After the two-step purification process, a product of 125 I -Tyr-PEG-TA1 with radiochemical purity of 95% and specific activity of 39.4 Bq/ng was obtained. Conclusion A successful preparation of 125 I -Tyr-PEG-TA1 was achieved, and the radiochemical purity and the specific activity of the ¹²⁵I labeled molecules satisfied the requirements of non-clinical pharmacokinetic study.;更多还原