A dilatation catheter for delivering a therapeutic agent within a body lumen having a wall with a thickness is provided having a balloon having a flexible wall including a polymer with dispersed nanotubes and pores configured to close below a predefined pressure and to open at or above a predefined pressure. In some embodiments, an actuator is provided to controllably inflate the balloon with a fluid at a pressure sufficient to bring the flexible wall of the balloon into contact with at least a portion of the wall of the body lumen but below the predefined pressure, and to controllably increase the pressure of the fluid within the inflated balloon to at least the predefined pressure at a rate and with a force sufficient to deliver the therapeutic agent from the pores and through at least a portion of the thickness of the wall of the body lumen.
