A micro-organ based microfluidic biosensor for continuous monitoring of glucose levels in vivo

Abstract Current approaches to detect analytes use biomolecules or single cells and thus do not harness the computational power of endogenous algorithms present in micro-organs. Consequently, current on-line detection of glucose does not allow an autonomous artificial pancreas. In contrast, monitoring a few electrogenic pancreatic islets may provide a more appropriate read-out. Indeed, upon stimulation islets react with so-called slow potentials (SP) and their amplitude reflects the degree of intercellular coupling. We have now developed a microfluidic microelectrode chip containing a few islets and linked to interstitial fluids in live rats by microdialysis. Blood and dialysate glucose were determined concomitantly with ex-vivo islet electrical activity during an intraperitoneal glucose or insulin challenge. Blood glucose was tightly correlated to islet SP frequency, and to a lesser degree to SP amplitudes. This demonstrates the feasibility and usefulness of microorgan-based biosensors which may also be of interest in the therapy of diabetes.