Monosialoganglioside containing cationic liposomes with a cationic cholesterol derivative promote the efficiency of gene transfection in mammalian culture cells

We have studied the effects of monosialoganglioside (GM(1))-containing cati onic liposomes with a cationic cholesterol on the liposome-mediated gene tr ansfection into mammalian culture cells. The results showed that both catio nic liposomes with either a cationic cholesterol derivative of a hydrophobi c amino head group (I) and a hydrophilic amino head group (II) promoted the transfection of lucliferase plasmids (pGL3) into HeLa and CHO-K1 cells mor e than the control cationic liposomes without GM(1). In addition, we found that cationic liposomes with a cationic cholesterol derivative (II) were ab out ten times as effect as that by commercially available cationic liposome Lipofectin. Confocal fluorescence microscopy showed that the liposome/DNA complex was transferred more efficiently into the target cells by the GM(1) -containing liposomes than by the liposomes without GM(1). In proportion to the above results, free antisense DNAs were also more efficiently transfer red into the nucleus of the target cells by the GM(1)-containing liposomes. When there was 100 mM galactose in the transfection medium, the luciferase activity by the GM(1)-containing liposomes was reduced to the level of the control liposomes. The results suggest that GM(1)-containing cationic lipo somes with a cationic cholesterol derivative of a hydrophobic amino head gr oup or a hydrophilic amino head group should significantly increase the tra nsfection efficiency of plasmid DNAs and antisense DNAs by galactose recept or-mediated endocytosis. This means that the GM(1)-containing liposomes des cribed here should he very promising for gene transfection in vitro.