A novel cationic cardiolipin analogue for gene delivery

The optically active R and S isomers of cationic cardiolipin analogues (CCA) were synthesized and evaluated as a liposome based transfection reagent. Both isomers form stable liposomes with mean diameters of about 120 nm without any additional lipid ingredients. No significant change in particle size distribution profile was observed over one-month storage at room temperature (20-25 degrees C). The gel to liquid crystalline phase transition temperature (Tm) of cationic liposomes comprised of both R and S isomers was approximately 2 degrees C, as measured by differential scanning calorimetry (DSC). Both isomers also formed stable liposomes when combined with DOPE. In vitro transfection efficiency of the CCA/DOPE liposomes complexed to plasmid DNA was evaluated using a luciferase reporter gene. Both liposomes composed of R and S isomers of the cationic cardiolipin displayed higher transfection efficiency than commercially available Lipofectin. Further in vivo studies are warranted.