New strategy in gene transfection by cationic transfection lipids with a cationic cholesterol

The present article reviews interesting cationic liposomes (cationic transfection lipids) with novel cationic cholesterol derivatives, a new strategy in gene transfection developed by our group and the presently accepted molecular mechanism of gene transfection. Use of confocal laser scanning microscopy and atomic force microscopy in elucidating the molecular mechanism of gene transfection by cationic liposomes is also reviewed using examples from our own work. As delineated below, both the confocal laser scanning microscopic and the atomic force microscopic results advocate for the involvement of the sequential three steps in gene transfection mediated by the cationic liposomes: endocytotic internalization of the lipoplexes (liposome-DNA complexes) into the target cells, endosome-lysosome fusion whereby the DNA gets released from the liposomes and moves towards the nucleus of the target cells and microtubule organization apparently involved in trafficking the transfected foreign genes to lysosomes. Furthermore, the present article also reviews couple of important strategies in gene transfection namely, use of liposomes made from biosurfactants and harnessing efficient gene transfection by activating the membrane-bound receptor molecules.