Abstract: A modular drug delivery system for use by cardiothoracic surgeons and interventional cardiologists for delivery of molecular and cellular therapies that target genes, molecules and peptides. The regulated drug delivery devices comprise a modular mechanically actuated drug delivery module (DDM) that can be attached to either a surgical viewing endoscope hand-piece or specialized catheter for interventional procedures. The DDM provides metering of drugs to treatment sites and allows for quick interchangeability with other component parts such as a viewing scope end portion for MIS or other surgical procedures or a flexible catheter shaft for percutaneous procedures.