Glucose-sensing and glucose-driven organic engine with co-immobilized enzyme membrane toward autonomous drug release systems for diabetes

In this study we report the enhanced performance of a glucose-sensing and glucose-driven organic engine (decompression unit) that can convert the chemical energy of glucose into mechanical energy for autonomous drug release without a need for electrical input. The novel chemical approach is based on increasing the effective decompression in the organic engine by fabrication of a co-immobilized enzyme membrane. Among the enzymes (glucose oxidase (GOD), pyranose oxidase (PDX), alcohol oxidase (AOX), galactose oxidase (GAO)) which can oxidize glucose and glucono-1.5-lactone (product of the glucose oxidation) evaluated in co-immobilization designs within the organic engine, the most effective decompression was obtained with PDX + GOD, which was 3 times higher than the conventional organic engine that obtained with the GOD membrane. Furthermore, the decompression rate of 7.4 Pa cm(3)Is in the organic engine necessary to drive the drug release system was obtained at 10 mmol/L glucose, which is close to the normal blood sugar level. Selectivity studies revealed no significant response of the GOD + PDX membrane to chemicals normally present in human blood except for ID-glucose and glucono-1.5-lactone. In conclusion, the organic engine is a promising device for development of a chemo-mechanical system with pancreas-like function actuated by human blood sugar for the treatment of Diabetes Mellitus. (C) 2013 Elsevier B.V. All rights reserved.