Glucose-sensitivity of glucose oxidase-containing cationic copolymer hydrogels having poly(ethylene glycol) grafts

Glucose oxidase and catalase were immobilized on poly(diethylaminoethyl methacrylate-g-ethylene glycol) gels by copolymerization of the constituent monomers and the functionalized enzyme solutions. The hydrogels were prepared in the form of discs and microparticles. The amount and the activity of enzymes immobilized in the matrix were determined. The hydrogels were tested for their response to glucose by exposing microparticles to varying concentrations of glucose. The generation of gluconic acid as a result of the reaction of glucose with oxygen was investigated as a function of polymer parameters, such as crosslinking ratio and enzyme loading. Pulsatile variation of the glucose concentration was used to confirm the glucose-dependent swelling properties of these hydrogels.