Delivery of DNA into skin via electroporation

Delivery of DNA into skin is an attractive method, because skin is the most accessible somatic tissue for gene transfer and can be monitored conveniently. Skin is especially suitable for immunization using plasmid-DNA-based vaccines; however, a low level of transfection is the major limitation to the use of DNA-based therapeutics. Several chemical and physical methods are being investigated to improve the transfection of target cells with plasmid DNA. Electroporation is a physical method of gene transfer by applying electric pulses to the target cells. Most of the electroporation studies involve insertion of electrode needles into the tissues. In this chapter, we discuss that the DNA delivery into skin can be greatly enhanced by topical electroporation of the DNA injection site in rabbits using a tweezer electrode. Furthermore, the immune responses following a DNA vaccine delivery by using electroporation have been explored. Electroporation shows great potential for enhancing the DNA delivery into the skin.