<sup>99</sup>Tc<sup>m</sup>标记的小干扰RNA探针的制备及稳定性评价

⁹⁹Tc^m标记的小干扰RNA探针的制备及稳定性评价

摘要: 通过偶联双功能螯合剂S-乙酰基-MAG₃以达到制备⁹⁹Tc^m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⁹⁹Tc^m-siRNA在反应时间大于1h、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，⁹⁹Tc^m-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。

Abstract: 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℃. ⁹⁹Tc^m-labeled siRNA has the same targeted inhibition activity as non-labeled siRNA.