[Transfection efficiency comparison of cationic liposome-DNA complexes and lipid-protamine-DNA complexes in vitro]

After the preparation of cationic liposomes composed of DDAB/DOPE, cationic liposome-DNA complexes and lipid-polycation-DNA (LPD) complexes were formulated, respectively. Gel retardation assay was employed to select appropriate ratios of cationic liposomes to DNA of the liposome-DNA complexes. The morphology of LPD and liposome-DNA complexes was observed by transmission electron microscopy. The diameter and surface charge of LPD and liposome-DNA complexes were measured by photon correlation spectroscopy (PCS). Their transfection efficiencies in Chang cells and HepG2 cells were evaluated by beta-gal assay kit. It was found that LPD and liposome-DNA complexes had a regular spherical surface. However, compared with liposome-DNA complexes, LPD had rather smaller particle size and much higher transfection efficiency in Chang cells and HepG2 cells in vitro. LPD could be prepared easily with small particle sizes and high transfection activities. LPD may be a good non-viral gene delivery vehicle for applications in gene delivery.