A method of localized delivery of a therapeutic and/or diagnostic agent to nasal tissue or cavities includes inserting a catheter into a nasal cavity, the catheter having an outer balloon with at least one opening therethrough and an inner surface, and an inner balloon disposed in the outer balloon and at least partially 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, supplying the agent to the space between the outer surface of the inner balloon and the inner surface of the outer balloon via a first lumen of the catheter, and inflating the inner balloon by supplying fluid to the inflation chamber via a second lumen of the catheter to urge the agent out of the opening in the wall of the outer balloon and into nasal tissue.
