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

Praneet Opanasopit¹, Orapan Paecharoenchai¹, Theerasak Rojanarata¹, Tanasait Ngawhirunpat¹, Uracha Ruktanonchai^2
1Faculty of Pharmacy, Silpakorn University, Nakhon Pathom, ²National Nanotechnology Center, Thailand Science Park, Pathumthani, Thailand

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^TM 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.

Keywords: polycation liposomes, polyethylenimine, gene delivery, transfection efficiency