The development of poly-L-arginine-coated liposomes for gene delivery

In this study, liposomes coated with cationic polymers, poly-L-arginine (PLA), were assessed as a promising gene transfer system in human cervical carcinoma (HeLa) cells and human hepatoma cell line (Huh7) cells. The liposomes were prepared using egg yolk phosphatidylcholine and sodium oleate in the molar ratio of 10:2 with an ultrasonic generator and then coated with PLA. The PLA-coated liposomes (PCLs) formed complexes with plasmid DNA encoding green fluorescent protein. The complexes were characterized by agarose gel electrophoresis and investigated for their transfection efficiency in HeLa and Huh7 cells. The data were compared with PLA/DNA complexes and the positive control Lipofectamine 2000(™). The results showed that complete PCL/DNA complexes were formed at weight ratios of more than 0.05. Efficient gene transfer by PCLs was dependent on the cell type. The transfection efficiency of PCLs was about two times higher than that of PLA/DNA complexes in both HeLa cells and Huh7 cells. Cytotoxicity was determined by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay and showed that 80%-100% of both of the cells were viable after treating PCL/DNA complexes. The present results demonstrate that PCLs are a promising, nonviral gene carrier with low toxicity.