"Smart Insulin Patch" Holds Promise for Type 1 Diabetes
(HealthDay News) — A microneedle-array patch ("smart insulin patch") containing glucose-responsive vesicles (GRVs), which are loaded with insulin and sensitive to hypoxia, can regulate blood glucose in a mouse model of type 1 diabetes. The findings were published online June 22 in the Proceedings of the National Academy of Sciences.
Jicheng Yu, PhD, from the University of North Carolina at Chapel Hill, and colleagues describe the smart insulin patch -- a novel glucose-responsive insulin delivery device. The patch contains GRVs, which are loaded with insulin and glucose oxidase enzymes.
The researchers note that the GRVs are self-assembled from hypoxia-sensitive hyaluronic acid (HS-HA) which is conjugated with 2-nitroimidazole. Under hypoxic conditions, the 2-nitroimidazole can be converted to hydrophilic 2-aminoimidazoles through bioreduction. Enzymatic oxidation of glucose in the hyperglycemic state, which causes a local hypoxic microenvironment, promotes the reduction of HS-HA, rapidly triggering vesicle dissociation and insulin release. In a mouse model of chemically-induced type 1 diabetes, the smart insulin patch regulated blood glucose.
"The described work is the first demonstration, to our knowledge, of a synthetic glucose-responsive device using a hypoxia trigger for regulation of insulin release," the authors write. "The faster responsiveness of this approach holds promise in avoiding hyperglycemia and hypoglycemia if translated for human therapy."