制备脂质体包裹的99m锝标记c-myc mRNA反义寡聚核苷酸的研究

探讨脂质体包裹的 99m-锝标记 c- myc m RNA反义寡聚核苷酸的制备方法 ,为反义显像和反义治疗的实验研究奠定基础。合成 15 bp的反义寡聚核苷酸 (DNA)和双功能螯合剂 -联肼尼克酰胺衍生物 ,DNA与双功能螯合剂偶联后 ,用 99m锝标记 ,然后用 C1 8Sep- Pak反相柱进行纯化 ,根据纯化结果 ,绘制淋洗曲线 ,计算标记率。再用阳离子脂质体对纯化产物进行包裹 ,获得脂质体包裹的 99m锝 - DNA。用纸层析测定脂质体包裹的 99m锝 - DNA的放射性化学纯度及与水、血清孵育后的稳定性。结果 ,不同放射性活度的 99m Tc O4 - 标记时的标记率为 :14 80 MBq时为 6 3.37%± 3.5 1% ,74 0 MBq时为 6 2 .5 2 %± 3.6 9% ,5 92 MBq时为 5 9.82 %± 5 .12 % ,经 χ2检验无显著性差异。脂质体包裹 99m Tc- DNA的放射化学纯度 =96 .4 7%± 3.0 1% ,与水、血清孵育后脱落的 99m Tc极少 ,可见 99m Tc- DNA的稳定性极好。由此可见 ,以脂质体作载体 ,联肼尼克酰胺衍生物作为双功能螯合剂 ,可制备脂质体包裹的 99m锝标记的单链寡聚核苷酸

Preparation of Liposome-mediated 99m-technetium-labeled Antisense Oligonucleotides of c-myc mRNA

To explore the preparation method of liposome-mediated 99m-technetium-labeled antisense oligonucleotides of c-myc mRNA and lay foundations for antisense imaging and treatment, antisense oligonucleotides (DNA) with 15 bases and di-functional chelate, hydrazino nicotinamide derivatives, were synthesized. After DNA combined with chelate, they were labeled with 99m-technetium to form compounds, 99mTc-chelate-DNA (99mTc-DNA), and were purified through Sep-Pak reverse column(C18, Waters) by using methanol and water as eluent. The leaching curve was made; the labeling efficiency was calculated. The products were then encapsulated with cation liposome to form liposome-mediated 99mTc-DNA. The radiochemical purity and stability of the liposome-mediated 99mTc-DNA were tested through strip chromatography. The labeling efficiency was 63.37% +/- 3.51% at the radioactive concentration of 1480 MBq, 62.52% +/- 3.69% at that of 740 MBq, 59.82% +/- 5.12% at that of 592 MBq. There were no significant differences between these labeling efficiencies. The radiochemical purity was 96.47% +/- 3.01%. The liposome-mediated radiolabeled antisense oligonucleotides were stable after incubation with water or serum. Therefore liposome-mediated radiolabeled antisense oligonucleotides could be obtained through hydrazino nicotinamide derivatives as di-functional chelate and liposome as vector.