A method for treating vulnerable plaques of a patient, comprising: providing a biodegradable stent comprising a first supporting zone made of a first biodegradable material, wherein the supporting zone comprises at least a portion of continuous circumference of the stent; and a second therapeutic zone made of a second biodegradable material, wherein the therapeutic zone comprises at least one bioactive agent; delivering the biodegradable stent to the vulnerable plaques; orienting the therapeutic zone at about the luminal surface of the vulnerable plaque; and releasing the at least one bioactive agent for treating the vulnerable plaques.