阳离子脂质体-DNA复合物与脂质-鱼精蛋白-DNA复合物体外细胞转染率比较

采用薄膜-挤压法制备空白阳离子脂质体后,再分别制得阳离子脂质体-DNA复合物和脂质-聚阳离子-DNA复合物(Lipid-polycation-DNA lipopolyplexes,LPD);用凝胶阻滞实验,确定阳离子脂质体与质粒DNA的配比;用透射电镜观察阳离子脂质体-DNA复合物和LPD的形态,用激光粒度仪测定它们的粒径和zeta电位;用酶标仪测定它们对张氏(Chang)肝细胞、HepG2肝癌细胞的转染率。结果表明阳离子脂质体-DNA复合物和LPD的形态均近似于球体,但LPD的粒径明显较小;LPD对张氏(Chang)肝细胞和HepG2肝癌细胞的转染率均高于阳离子脂质体-DNA复合物。LPD是基因治疗的临床应用中一种更具前景的载体系统。

Transfection Efficiency Comparison of Cationic Liposome-DNA Complexes and Lipid-Protamine-DNA Complexes In Vitro

After the preparation of cationic liposomes composed of DDAB/DOPE, cationic liposome-DNA complexes and lipid-polycation-DNA (LPD) complexes were formulated, respectively. Gel retardation assay was employed to select appropriate ratios of cationic liposomes to DNA of the liposome-DNA complexes. The morphology of LPD and liposome-DNA complexes was observed by transmission electron microscopy. The diameter and surface charge of LPD and liposome-DNA complexes were measured by photon correlation spectroscopy (PCS). Their transfection efficiencies in Chang cells and HepG2 cells were evaluated by beta-gal assay kit. It was found that LPD and liposome-DNA complexes had a regular spherical surface. However, compared with liposome-DNA complexes, LPD had rather smaller particle size and much higher transfection efficiency in Chang cells and HepG2 cells in vitro. LPD could be prepared easily with small particle sizes and high transfection activities. LPD may be a good non-viral gene delivery vehicle for applications in gene delivery.