GLUCOSE-RESPONSIVE INSULIN RELEASE FROM POLY(VINYL ALCOHOL)-BLENDED POLYACRYLAMIDE MEMBRANES CONTAINING GLUCOSE-OXIDASE

Abstract

Glucose-sensitive membranes that can increase their permeability in the presence of glucose have been developed. Membranes are fabricated by free-radical polymerization of acrylamide and poly (vinyl alcohol) blends, containing glucose oxidase (GOD). The polymers are hydrogels, with water content in the range of 85-95%, depending on the pH or glucose concentration. The gluconic acid produced by an enzymatic reaction between glucose oxidase and glucose induces a decrease in pH value of the medium. This may causes the protonation of the amino groups in the membrane, resulting in an increase in water content of the polyamine membrane or which changes the solubility of insulin and the diffusional driving force. The in vitro retention of the enzyme activity by the membrane is also reported. It appears that the problem of membrane rupture may be alleviated by the blending of polyacrylamide (AA) with poly(vinyl alcohol) (PVA), since they have demonstrated an improved wet strength, without altering their insulin-transport properties. This preliminary report proposes the possibility of developing glucose-sensitive membranes for controlled delivery of insulin and also benefits from ongoing research on biosensors.