In vivo transfer of genetic information to cells of the skin may offer a useful therapy for skin-specific indications as well as systemic diseases such as hemophilia. The skin presents a large, easily accessible target that contains cells such as keratinocytes that can provide secretory capability to the circulatory system. Currently, the greatest obstacle to skin-targeted gene therapy is the lack of a simple and effective delivery system. The transient nature of transgene expression in the epidermis demands that the delivery method be readily repeatable, and thus preferably based on the use of naked DNA. We present here a novel method, based on the electroporation of naked DNA, for topical delivery of DNA to human skin. The purpose of the Phase I study plan is to advance our preliminary data on gene transfer and develop an optimized, effective protocol for targeting keratinocytes in human skin xenografts. In Phase II and beyond, our goal is the development of a therapeutic method and device for the treatment of hemophilia A and B. PROPOSED COMMERCIAL APPLICATION: The goal of this research is the development of a novel gene delivery method and device that will enable us to enter clinical trials for gene therapy. Ultimately we envision the creation of a small, hand-held, battery-operated applicator. The device would enable the user to safely self-administer a pharmaceutically prepared packet of therapeutic DNA directly to the skin through the use of disposable electrodes.