GFP质粒DNA/阳离子脂质体复合物的制备及其体外表达

目的 为基因免疫和基因治疗寻找一种简单、经济、有效的DNA投递系统。方法 采用逆向蒸发法，用卵磷脂、胆固醇、十八胺制备成阳离子脂质体包封含绿色荧光蛋白基因的真核表达质粒pEGFPC1，对三种不同DNA加入量所形成的DNA／脂质体复合物的微球形、包封率、电荷性、转染真核细胞的效果以及对细胞的毒性作用进行初步检测研究。结果 所获得的DNA／脂质体复合物呈球形、平均粒径为562nm；包封率达55％～65％，为阳离子脂质体；都能有效转染真核细胞，但转染效率有差异，DNA／脂质体混悬液中DNA含量、混悬液的加入量以及细胞的作用时间，都对细胞毒性有不同程度的影响。结论 该方法可作为提高基因免疫效果的简单、经济、有效的手段之一。

Preparation and Transfection of GFP Plasmid DNA/Cationic Liposome Complex

Objective This work was directed at obtaining a better gene carrier to improve the effects of gene delivery. Methods Cationic liposomes made from cholesterol, lecithin and Eighteenth Amic by reverse evaporation technique were used for encapsulating plasmid DNA containing gfp gene. The DNA/liposome complexes differed in quantity of plasmid DNA. The sizes of complexes and the efficiency of encapsulation were detected. MTT assay was used to measure the cytotoxicities of complexes. The efficiency of transfection into COS1 cells was shown by observation of green fluorescent and measurement of fluorescent intensity. Results The average size of complexes was 562 nm, the encapsulating efficiency of DNA in microspheres reached 55%-65%. These DNA/Cationic liposome complexes could be transfected into mammalian cells, but they were different from each other in efficiency of transfection. The cytotoxicities of these complexes varied with the concentration of DNA in complexes, the quantities of complexes and the time of treatment by complexes. Conclusion DNA/Cationic liposome complexes prepared by reverse evaporation technique could be applied in DNA delivery system.