血清蛋白与阳离子多糖的质量比对RNAi效率的调控作用研究

Relationship Between Serum and RNAi Efficiency

阳离子多糖可以通过静电相互作用与核酸分子相结合,并具有水溶性好和易被生物体降解的优点,是具有潜在临床应用价值的核酸载体.但是,在血清存在的环境中,阳离子多糖与si RNA形成的复合物会吸附血清蛋白,这是影响RNA干扰效率的主要原因之一.本文以精胺化普鲁兰多糖(Ps)作为阳离子多糖的模型材料,通过凝胶电泳、等温滴定量热、动态光散射和流式细胞分析方法研究了血清蛋白(Pr)与Ps的质量比(Pr/Ps)对Ps/si RNA复合物的颗粒尺寸及RNA干扰效率的影响.结果显示,Pr/Ps对复合物的颗粒尺寸及其进入细胞的能力均起着重要的调节作用,由此而影响RNA干扰的效率.

Cationic polysaccharide is a promising si RNA carrier for its water-solubility, biodegradable character, and the binding ability with nucleic acid. However, the low RNA interference activity in serum containing conditions caused by the adsorption of serum protein is a big barrier for its clinic use. In this study, spermine modified pullulan（pullulan-spermine, Ps）, a cationic polymer carrier, was used as a model material to study its hydrodynamic diameter, cell internalization character, and RNAi efficacy in different serum containing conditions. Results showed that the relative amount of protein and Ps could regulate the particle size of Ps/si RNA complex and finally affect the Ps mediated RNAi efficiency.