Topical gene transfer into rat skin using electroporation

Purpose. To investigate whether electroporation can be used for topical gene delivery and far DNA expression in rat keratinocytes. Methods. The localization of a fluorescent-labelled plasmid and the expression of a reporter gene (pEGFP-N1) coding for Green Fluorescent Protein (GFP) in stripped skin were assessed by Confocal Laser Scanning Microscopy (CLSM). Results. The plasmid penetrated into the epidermis within minutes after electroporation and entered the keratinocyte cytoplasm within hours. A localized expression of GFP was observed for at least 7 days in the epidermis. Skin viability was not compromised by electroporation. Conclusions. Electroporation enhances the delivery, and hence the expression, of topically applied plasmid DNA on the skin. It could be a promising alternative method to administer DNA, particularly for DNA vaccines, in the skin in vivo.