Method and apparatus for delivery of therapeutic agents

Methods and apparatus for the reproducible, consistent and efficacious delivery of a therapeutic agent to a subject, such as nucleic acids, drugs, peptides, and proteins or combinations thereof, to defined regions in selected tissues of interest, facilitated by the local application of electrical fields, in a safe, effective, and consistent fashion across heterogeneous recipient populations with minimal user training. The apparatus for a controlled delivery of the therapeutic agent to a predetermined tissue site within a subject, the apparatus comprising: a cartridge assembly comprising an outer cartridge, an inner cartridge, a vessel configured to contain the therapeutic agent, and a needle hub, wherein the outer cartridge provides a vessel receiver configured to receive the vessel; an applicator comprising a cartridge assembly receiver configured to receive the cartridge assembly or a portion thereof, and a vessel insertion detector, comprising a sensor that senses the vessel having been loaded in the vessel receiver; a vessel interlock, wherein the vessel interlock is configured to lock out the apparatus from actuation until the vessel is loaded properly in the vessel receiver; at least one injection orifice in fluid communication with the therapeutic agent when the therapeutic agent is loaded in the vessel and through which the therapeutic agent is administered; a plurality of penetrating electrodes arranged with a predetermined spatial relationship relative to the at least one injection orifice; an electrical field generator configured to generate an electrical signal, wherein the electrical field generator is operatively connected to the plurality of penetrating electrodes; and a controlled source of energy sufficient to transfer a predetermined amount of the therapeutic agent from the vessel through the at least one injection orifice to the predetermined tissue site within the subject.