Purpose To develop a novel non-viral gene delivery systems—liposome-PEI-DNA ternary complexes(TC) and to investigate their stability in human plasma and transfection efficiencies in vitro.Methods TC were prepared by first mixing the plasmid DNA with polyethylenimine (PEI), and then by incubating the resulted polyplexes for 30 min at room temperature, followed by addition of preformed anionic liposomes. The physico-chemical properties, stability in plasma, the protection effect on DNA from nuclease degradation, in vitro cytotoxicity as well as transfection activity in Hela cells were evaluated respectively. Results The obtained DNA loaded TC were approximately spherical in shape with average particle size of 234.3 nm and Zeta potential of - 20.72 mV. TC could protect the plasmid DNA from nuclease degradation after 2 h incubation at 37 ℃ while the naked DNA degraded rapidly. TC stayed stably for 4 h without apparent aggregation. It showed low cytotoxicity to Hela cells and could transfer the loaded gene into Hela cells both in serum free medium and serum medium. Conclusion TC could be prepared easily with stability in human plasma and high transfection activities. It may be a good non-viral vector for applications in gene delivery. It has the potential to make in vivo gene therapy achievable.%目的 研究非病毒基因栽体脂质体-聚乙烯亚胺(PEI)-DNA三元复合物(TC)的制备方法,评价其体外细胞学性质.方法 采用乙醇注入法制备空白阴离子脂质体,与PEL/DNA复合物37℃孵育30 min后,得到TC,考察其理化性质、抗核酸酶降解能力、血浆稳定性、细胞毒性及在卵巢癌细胞(Hela)中的转染效率.结果 制备的TC呈类球形,大小较均匀,平均粒径为234.5 nm,Zeta电位为-20.72 mV;TC能在血浆中稳定存在4 h而不发生聚集;与核酸酶作用2 h后,其中的DNA几乎无降解;其细胞毒性较低,在无血清和含血清培养基中均能成功的转染Hela细胞,在舍血清培养基中其转染效率明显高于PEI/DNA复合物.结论 TC是一种制备工艺简单、血浆稳定性好、转染率较高、极具应用潜力的非病毒纳米基因载体.
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