Enzymatically controlled responsive drug delivery systems

This paper discusses two approaches for the preparation of enzymatically controlled drug delivery systems: (i) a calcium-responsive biodegradable drug delivery system based on a mixture of starch with HPMC (hydroxypropyl methyl cellulose ether) (biodegradable) and the starch hydrolytic enzyme, α-amylase, in its non-active form; (ii) a glucose-responsive insulin delivery system based on the hydrogel poly(2-hydroxyethyl methacrylate-co-N,N-dimethylaminoethyl methacrylate), with entrapped glucose oxidase, catalase and insulin. In both systems, the sensitivity to a trigger molecule (calcium or glucose) was achieved by the incorporation of a specific enzyme that reacts with the trigger molecule. Based on these interactions we propose two different enzyme-controlled drug release mechanisms for responsive drug delivery systems.