The present invention provides dynamic charge state cationic polymers that are useful for delivery of anionic molecules. The dynamic charge state cationic polymers are designed to have cationic charge densities that decrease by removal of removable functional groups from the polymers. The present invention also provides interpolyelectrolyte complexes containing the polymers complexed to a polyanion. Methods for using the interpolyelectrolyte complexes to deliver anionic compounds are also provided.
