A balloon catheter for delivering a therapeutic and/or diagnostic agent to tissue is described including an outer balloon having a wall with an opening therethrough and an inner surface, an inner balloon disposed in the outer balloon, enclosing an inflation chamber and having an outer surface defining a space between the outer surface of the inner balloon and the inner surface of the outer balloon, a catheter having a first lumen in fluid communication with the space between the inner balloon and the outer balloon for supplying the agent thereto, and a second lumen through which fluid is supplied to the inflation chamber for inflating the inner balloon to urge the agent out of the opening in the outer balloon, wherein the outer balloon and/or the inner balloon comprise at least one protrusion for directing the agent formed by an inner balloon wall and/or the outer balloon wall.