Type and composition of surfactants mediating gene transfection of polyethylenimine-coated liposomes

BACKGROUND The objective of this study was to compare the transfection efficiency of anionic liposomes coated with polyethylenimine (PEI) with that of PEI and Lipofectamine 2000(™) using the plasmid DNA encoding green fluorescent protein in a human hepatoma (Huh7) cell line. METHODS Factors affecting transfection efficiency, including type of surfactant, ratio of phosphatidylcholine (PC)/surfactant, carrier/DNA weight ratio, and the presence of serum have been investigated. Anionic liposomes, composed of PC and anionic surfactants, ie, sodium oleate (NaO), sodium taurocholate (NaT), or zwitterionic surfactant (3-[{3-cholamidopropyl}-dimethylammonio]-1-propanesulfonate, CHAPS) at molar ratios of 10:1, 10:1.5, and 10:2 were prepared by the sonication method. Subsequently, they were coated with PEI to produce polycationic liposomes (PCL). RESULTS PCL was able to condense with pDNA depending on the PCL/DNA weight ratio. PCL composed of PC:NaO (10:2) showed higher transfection efficiency than NaT and CHAPS at all weight ratios tested. Higher transfection efficiency and gene expression were observed when the carrier/DNA weight ratio increased. The highest transfection efficiency was found at a weight ratio of 0.5. CONCLUSION This PCL showed remarkably high transfection efficiency with low cytotoxicity to Huh7 cells in vitro, in comparison with PEI and Lipofectamine 2000.