Enzyme-digestible swelling hydrogels as platforms for long-term oral drug delivery: synthesis and characterization.

A method was developed for synthesizing enzyme-digestible swelling hydrogels. Albumin molecules were modified using glycidyl acrylate to introduce vinyl groups. The functionalized albumin molecules participated as cross-linkers in the polymerization of vinyl monomers, such as acrylic acid or acrylamide. The extent of chemical modification of albumin was an important variable in controlling the cross-linking ability. The albumin in the synthesized hydrogels retained its property of enzymatic digestion by proteolytic enzymes. The kinetics of swelling and enzymatic digestion of the hydrogels were examined using various enzyme concentrations. It was observed that the digestion kinetics were largely determined by the relative concentrations of albumin and enzyme. The potential application of the enzyme-digestible swelling hydrogels as platforms for long-term oral drug delivery is discussed.