Cationic cholesterol with a hydroxyethylamino head group promotes significantly liposome‐mediated gene transfection

A novel cationic cholesterol derivative with a hydroxyethylamino head group, cholesteryl-3beta-carboxyamidoethylene-N-hydroxyethylamine (II), has been synthesized and used for liposome-mediated gene transfection. The cationic liposomes containing the derivative (II) facilitated greatly pSV2CAT gene transfection into mouse NIH3T3 and L929 cells in the absence of serum. The transfection efficiency was much higher than those by the cationic liposomes containing cationic derivatives with a dialkylamino head group (I, III or IV). Further, the efficiency by the cationic liposomes with the derivative (II) was not so much decreased in the presence of serum. This suggested that a novel cationic cholesterol derivative (II) should be very promising in liposome-mediated gene transfection of plasmid and antisense DNA into target cells.