壳聚糖-聚乙二醇纳米粒介导的Survivin RNAi基因纳米复合物的制备及其特性研究

Preparation and characterization of PEGylated chitosan/ survivin siRNA complex

目的制备壳聚糖-聚乙二醇纳米粒介导的survivinRNAi基因纳米复合物,并对其相关性质进行评价。方法通过接枝共聚法制备出空白壳聚糖-聚乙二醇纳米粒;通过静电吸附作用连接基因质粒形成基因纳米复合物。并对基因纳米复合物的包封率进行测定;通过DnaseⅠ消化壳聚糖-聚乙二醇纳米-质粒结合物以观察纳米载体对质粒的保护作用;通过对比基因-纳米复合物与裸基因对基因-纳米复合物的转染效率进行评价。结果经电镜检测表明壳聚糖-聚乙二醇纳米粒呈球形,粒度分布均匀,粒径集中在60nm左右;琼脂糖凝胶电泳的结果显示纳米粒能有效地保护基因质粒;不同基因纳米比的基因-纳米复合物对质粒的保护作用不同;DnaseⅠ消化试验证实壳聚糖纳米载体对质粒DNA有保护作用。结论制备出的壳聚糖-聚乙二醇纳米粒粒度均匀,并且能有效地连接上质粒并对其有保护作用。壳聚糖-聚乙二醇纳米粒介导的survivinRNAi基因纳米复合物克服了RNA干扰在肿瘤的基因治疗中作用短暂和不能持久作用的不足。

[Objective] To prepare PEGylated chitosan/survivin siRNA complex and investigate its properties. [Methods] Blank PEGylated chitosan nano-particles were prepared by grafting eopolymerization method; then static electric adsorption method was used to obtain the gene-nano complex. The rate of envelopment of the complex was evaluated. And the protective effect of the particles was measured by Dnase I test. The transfection rate of the genenano complex was compared with that of the naked gene. [Results] The transmission electron microscope （TEM） photograph showed that the blank PEGylated chitosan particles are of stable dispersion, with a diameter of about 60 nm, which meet the reqirements of nano-materials. The agarose gel eleetrophoresis test showed that nano-particles could effectively protect the plasmid, and different rate of DNA to nano-particles had different protective effect; Dnase I test proved that the nano-particles could protect the plasmid. [Conclusion] The PEGylated chitosan nano- particles can effectively protect the plasmid; and the gene-nano complex can overcome the shortage of sutwivin RNAi a/one.