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 (POX), 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 POX + 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 cm3/s 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 + POX membrane to chemicals normally present in human blood except for d-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.