Biosurfactants of MEL-A increase gene transfection mediated by cationic liposomes

Many microorganisms growing on water-insoluble substrates have been known t o produce surface-active compounds called biosurfactants. Although biosurfa ctants have received increasing attention due to their special properties, there has been no information available until now of a role for them with r egard to gene transfection. Thus, we studied here the effects of biosurfact ants on gene transfection by cationic liposomes with a cationic cholesterol derivative. Our results showed clearly that a biosurfactant of mannosylery thritol lipid A (MEL-A) increased dramatically the efficiency of gene trans fection mediated by cationic liposomes with a cationic cholesterol derivati ve. Among them, the liposomes with a cationic cholesterol derivative, chole steryl-3 beta -carboxyamindoethylene-N-hydroxyethylamine (I), were much mor e effective for gene transfection than the liposomes with DC-Chol (choleste ryl-3 beta -oxycarboxyamidoethylenedimethyl-amine) or liposomes without MEL -A in various cultured cells. This demonstrates that this new finding has g reat potential in the experiment of gene transfection and gene therapy medi ated by nonviral vectors such as cationic liposomes. (C) 2001 Academic Pres s.