壳聚糖脂质体复合载体的核酸递送

目的构建一种由脂质体Lipofectamine2000、低分子质量壳聚糖、pDNA组成的三元新型复合载体用于核酸递送能力研究。方法复合物形态采用原子力显微镜轻敲模式下表征、载体与核酸结合能力采用凝胶延滞法表征,Hep-2细胞报告基因表达利用倒置荧光显微镜检测。细胞毒性研究采用3-甲基-2-噻唑硫酮(MTT)法。结果复合载体与pDNA结合能力强,可完全延滞pDNA。脂质体/壳聚糖/pDNA复合载体形态呈现出未完全压缩的球形,短棒状和不规则的聚集块。新型载体转染Hep-2细胞提高了绿色荧光蛋白报告基因的表达效率。与脂质体对照载体比较,基因转染效率提高了2～4倍,对照壳聚糖载体无明显转染效果。细胞毒性表明壳聚糖降低了脂质体的细胞毒性。结论基于脂质体的壳聚糖新型复合载体具有核酸递送潜力。

Chitosan and cationic liposome complex vector for gene delivery

Objective To construct a new type of stable ternary complex by mixing Lipofectamine2000 with chitosan/pDNA polyplex for delivery of plasmid DNA.Methods Morphology of liposome/chitosan/pDNA was characterized by atomic force microscopy(AFM) in tapping model.Vectors could bind pDNA sufficiently,which can be measured by gel retarding.GFP gene expression in Hep-2 cells in vitro was imaged by inverted fluorescence microscope.Cell toxicity was evaluated by MTT assay.Results Complex vector did combine pDNA and retard it completely.The liposome/polymer/pDNA complexes were incompacted spheroids,short rod and irregular lump of larger aggregates in structure.The transfection efficiency of the lipopolyplexes showed higher GFP gene expression than Lipofectamine2000/pDNA and CTS/pDNA controls.It was 2-to 4-fold than Liposome/pDNA control,while CTS/pDNA had few expression.Chitosan reduced cell toxicity of liposome.Conclusions New ternary complex has very higher transfection potential in gene delivery.