The present invention provides apparatus and methods for treating tissue by delivering at least one therapeutic agent to the tissue. In one embodiment, the apparatus comprises first and second membranes (30,32) in sealing engagement with strut segments (25,26) of at least one stent. A first membrane pocket is disposed between the first and second membranes(30,32), and a first therapeutic agent is disposed within the first membrane pocket. In other embodiments, the first and second membranes (130, 140) may be disposed between first and second spaced apart stents (114, 122), or only a single membrane may be provided. In each instance, the quantity of the therapeutic agent delivered is not limited by the surface area of the stent struts or the lumen diameter of the struts.
