^(99)Tc^m标记的小干扰RNA探针的制备及稳定性评价

Preparation and Stability Evaluation of Small Interference RNA Radiolabeled With ^(99)Tc^m

通过偶联双功能螯合剂S-乙酰基-MAG3以达到制备99Tcm标记的小干扰RNA探针的目的,并对其标记条件及体外稳定性进行评价。结果表明,室温下99Tcm-siRNA在反应时间大于1 h、SnCl2.2H2O质量浓度小于2 g/L时,标记率可达(73.4±3.0)%;经Sephadex G25纯化后其放化纯度大于92%,比活度达25.9 PBq/mol;在室温和37℃条件下,99Tcm-siRNA于生理盐水和血清中均保持良好的标记稳定性;标记后的siRNA探针与未标记探针具备相似的靶向干扰活性。

This study was to develop an available method of radiolabeling siRNA via conjugation with chelator of S-acetyl NHS-MAG3,and to evaluate its radiolabeled efficiency and stability in vitro.At room temperature,the labeling efficiency reaches（73.4±3.0）% under the reaction condition of reaction time above 1 h,and ρ（SnCl2·2H2O）2 g/L.After Sephadex G25 purification,the radiochemical purity is no less than 92% and the specific activity is up to 25.9 PBq/mol.In different mediums of saline and fresh human serum,the radiochemical purity keeps high stability in room temperature and 37 ℃.99Tcm-labeled siRNA has the same targeted inhibition activity as non-labeled siRNA.