Delivery devices, systems and methods for delivering therapeutic agents

A device for delivering an agent to a treatment site, comprising:

• a sheath having a first end, a second end, and a length between the first end and the second end, the sheath having an outer diameter, the sheath including a section that is configured to reversibly depress from the outer diameter, the sheath including at least one penetrating member configured to be movable between an aligned position and a protruded position with respect to the length disposed at the section;
• and
• an elongate member having a first end, a second end, and a length between the first end and the second end, the elongate member being configured to move relative to the sheath;
• wherein the aligned position corresponds to when the penetrating member is parallel with the outer diameter and the protruded position corresponds to when the penetrating member protrudes from the outer diameter into the treatment site;
• and
• wherein the elongate member includes a plurality of sections, at least one of the sections of the elongate member being configured to control the position of at least the penetrating member based on position of the elongate member with respect to the sheath.