Abstract
Immobilization of enzymes on suitable supports is an interesting area of investigation to increase their application spectrum in the synthetic, therapeutic and biosensor fields. In the present study, a new series of nanogels was used for the immobilization of glucose oxidase (GOx). Nanogels based on poly(acrylic acid) cross-linked with N,N-methylene bisacrylamide were synthesized using a surfactant free emulsification method. The carboxylic groups of the assynthesized nanogels were further functionalized to azide and isocyanate forms. The activity assay of the free GOx and the GOx-immobilized-nanogels was carried out using a standard protocol. The GOx-immobilized nanogels were investigated as devices for the loading and release of insulin. Nanogels were characterized by various techniques to obtain evidence of nanogel formation and GOx immobilization. The activity of various GOx-immobilized nanogels was observed to be dependent on the structure of the nanogels. The activity, thermal stability and substrate affinity of GOx were enhanced after immobilization. Excellent reusability of nanogels was observed up to ten repeat cycles. The GOx immobilized nanogels were loaded with insulin and the release study of the latter was carried out in the presence of glucose, the GOx substrate, under the physiological conditions.
Keywords: Glucose oxidase, immobilization, insulin, nanogel, loading, reusability, support.