MEMBRANE ELECTROPORATION AND DIRECT GENE-TRANSFER

The direct transfer of genetic material into cells by electroporation can be described in physicochemical terms as an electroporation-resealing hysteresis. The hysteresis concept includes unidirectional state transitions of the membrane, coupled to electrodiffusive migration of DNA through cell wall structures and electroporated plasma membranes. Deeper insight into electroporation phenomena such as electrotransfection, electrofusion and electro-insertion is gained by the inspection of the electrosensitivity and the recovery curves of cell populations as well as by the analysis of the pulse strength-duration relationship. A theoretical framework is developed for an adequate comparison of data obtained with different pulse shapes. The results of the physicochemical analysis of electroporation data not only indicate possible molecular mechanisms but are also instrumental in developing a goal-directed optimization strategy for the various practical applications of electroporation techniques such as electric gene delivery, production of hybridoma cells for antibody secretion or the insertion of immune proteins into the membranes of blood organelles.