Electroporation-Based Gene Transfer

When an external electric field, under specific pulse conditions, is applied to cells, in suspension or in biological tissues, the permeability of cell membranes is transiently increased. This physical method, termed electroporation, can be used to introduce poorly or non permeant molecules into the cell. The combination of electroporation and chemotherapy is termed electrochemotherapy. Electrochemotherapy enhances local cytotoxicity of hydrophilic drugs that do not easily pass the cell membrane, e.g. Bleomycin. This combination treatment has proven effective in local control of metastatic tumour nodules to the skin, independently of the histotype. Delivery of genetic materials into the target tissues or cells by means of electric pulses is referred to as electroporation based gene transfer. Gene expression level and kinetic patterns after in vivo electroporation mediated delivery can be optimized and adapted for different purposes by employing different applicator configuration, electrical parameters, and target tissues of delivery. The current chapter discusses present knowledge of nonviral gene delivery, the mechanism of DNA electrotransfer, and clinical applications focusing on delivery to skeletal muscle and skin. An overview of the equipment, tissue electroporation device and electrodes, currently available for clinical use of electroporation based gene transfer is provided.