Transfection of BHK cell by serum-stabilized cationic liposome-DNA particles

Cationic liposomes complexed with DNA have been used extensively as non-viral vectors for the intracellular delivery of reporter or therapeutic genes in cell culture and in vivo transfection experiments. Most of cationic liposome-DNA particles will be cleared from the blood very quickly when they were administered into the blood circulation system. Serum-stabilized cationic liposome-DNA particles made by preformed vesicles and ethanol method were developed [1]. Steric stabilization confers long circulation times to these particles, allowing them to extravasate more easily at sites of porous vasculature. In vitro transfection potency was evaluated by culturing with BHK cells. Experimental results show that the cell uptake of cationic liposome-DNA particles made by DO-DAP/DSPC/Chol /PEG-CerC 14 (25/20/45/10 mol%) was higher than that of made by DO-DAP/DOPE/Chol /PEG-CerC 14 (20/50/20/10 mol%). However, the transfection efficiency of liposome-DNA particles made by DODAP/DOPE/Chol /PEG-CerC 14 (20/50/20/10 mol%) was much higher than the liposome-DNA particles made by DODAP/DSPC/Chol /PEG-CerC 14 (25/20/45/10 mol%). This confirms that DOPE is a transfection helper lipid. Except the DOPE, the concentration of calcium ion also plays an important role in the BHK transfection experiments. 10 mM Ca ++ was necessary for achieving high transfection efficiency.