In vivo methods are provided for using an electric field to delivery
therapeutic treatment to a subject while reducing inducement of
histopathological change in the target muscle tissue, such as is
associated with induction or amplification of an immune response caused
by the pulsed electric field. Therapeutic agents can be delivered nto
cells of muscle for local and systemic treatments with optimal gene
expression and minimal tissue damage. In particular, therapeutic agents
include naked or formulated nucleic acid, polypeptides and
chemotherapeutic agents.