Compositions and methods for use with substrates which are useful in the
sustained delivery of bioeffecting agents are described. The compositions
of the invention include a multicomponent complex which attaches a
bioeffecting agent to a substrate with an anchor provided by a linker
compound which also forms a cleavable linkage so that the bioeffecting
agent's release into the area surrounding the substrate occurs in a
sustained manner over an extended period of time. The methods of the
invention involve providing a bioeffecting composition on the surface of a
substrate so that a bioeffecting agent may be released in a sustained
manner over time.