ABSTRACT
INTRODUCTION The skin represents an attractive site for the delivery of nucleic-acid-based drugs for the treatment of topical or systemic diseases and immunization. However, attempts at therapeutic cutaneous gene delivery have been hindered by several factors. Usually, except for viral vectors, gene expression is transient and typically disappears with one to two weeks due to the continuous renewal of the epidermis. Moreover, DNA penetration is limited by the barrier properties of the skin, rendering topical application rather inefficient.
