DEVELOPMENT OF EXPERIMENTAL INSULIN PUMPS WITH GLUCOSE-CONTROLLED RELEASE

In the present investigation, experimental insulin pumps have been developed in which the release of insulin is governed by the glucose concentration. The mechanical energy required for the glucose-dependent emptying of the insulin reservoir is provided by the carbon dioxide formed on the interaction of glucose with yeast cells. The developed pumps consist of a delivery unit containing an insulin reservoir and a reaction chamber in which 50 mg freeze-dried yeast and 150 mu l glucose solution are incubated. Variable glucose-dependent insulin release could be obtained by using an exchangeable bioreactor, which is replaced at given intervals by a new bioreactor containing fresh supplies of freeze-dried yeast and glucose solution. The results with solutions of 100, 200, and 400 mg glucose per 100 ml show that insulin release kinetics are directly affected by the glucose concentration