Enzyme‐Responsive Polymer Hydrogel Particles for Controlled Release

Abstract

An approach based on an enzyme-responsive chemically crosslinked hydrogel that undergoes a macroscopic transition such as hydrogel swelling, when triggered by a target protease, resulting in release of entrapped molecules was analyzed. Polyethylene glycol (PEG)-based crosslinked polymers were modified with peptides providing dual functions, thus creating a zwitterionic peptide that confers no overall charge when coupled to a hydrogel. The enzyme responsiveness of the PEGA particles was studied using three complementary methods that included analysis of accessibility of the hydrogel by two-photon microscopy, high-performance liquid chromatography (HPLC) analysis, and particle diameters obtained by optical microscopy. It was observed that the hydrogel responds by swelling specifically in response to target enzymes based on the enzyme cleavable linker employed in the PEGA-coupled peptide chain.