An increase in agent residence time at a tissue site is provided for by the presence of a barrier. The barrier is a separate entity from the agent when introduced to the tissue. A binding member is included in the barrier for coupling the barrier to the surface of the tissue. In one embodiment, agent is introduced to the tissue prior to attachment of the barrier to the tissue. In another embodiment, agent is presented after the barrier is positioned on the tissue surface. A delivery vehicle may be used to administer the agent and barrier to a patient.