Electrophysiological characterization of ion channels in beta-cells using silicon based lateral patch clamp device

Abstract

Metabolic syndrome, a collection of metabolic abnormalities including diabetes and obesity, affects hundreds of millions of people, and poses a major financial burden to public healthcare around the world. There are two major types of diabetes: Type-1, which is caused by a lack of insulin production and Type-2, which results from a relative deficiency of insulin secretion. Electrical activity of various ion channels in beta (β)-cells plays an important role in the stimulus-secretion of insulin in Type-2 diabetes. Here, we utilize a silicon based lateral patch clamp device to conduct whole cell patch clamp measurements in insulin secreting rat insulinoma (INS-1) cells. High gigaohm seals were achieved between the microfabricated glass capillary apertures and INS-1 cells resulting in picoampere current recordings from various potassium and calcium ion channels. Steady state I–V plots elicited characteristic ion channel properties and longevity of the whole cell mode could be maintained for 1 h without any breakage of the gigaohm seal. Glucose dose responses were also recorded and showed proportional current responses in voltage gated potassium channels. Delivery of multiple ion channel blockers (sulfonylurea drugs) resulted in suppression of currents in potassium channels. The results showcase the capability of our device in performing whole cell measurements and pave a way for developing a cheap platform using our silicon based approach.