Abstract
J Yu, Y Zhang, Y Ye, et al.
Proc Natl Acad Sci 2015; 112: 8260–8265.
The development of a glucose-responsive ‘closed-loop’ insulin delivery system mimicking pancreatic function has the potential to greatly improve quality of life and health in diabetics. Current systems couple implantable continuous glucose monitors to implantable pumps, which deliver insulin subcutaneously via a cannula. However, issues surrounding multiple calibrations, a ‘lag’ in blood glucose measurement and risk of infection have hampered their use in clinical practice.
Yu et al. describe a glucose-responsive-microneedle patch that can be painlessly applied to the skin and that releases insulin in response to glucose. The nanoparticles in each needle contain insulin and glucose oxidase. These molecules are surrounded by hypoxia-sensitive hyaluronic acid-based vesicles which rapidly dissociate and release encapsulated insulin under the local hypoxic environment, caused by the enzymatic oxidation of glucose in the hyperglycemic state.
Using mouse models of type 1 diabetes, the authors demonstrate that the patch effectively regulates glucose after dosing with a glucose load. Once blood glucose normalized, insulin release ceased. Serial administration of patches produced prolonged euglycaemia. The faster responsiveness of this approach holds promise in helping people with diabetes manage their condition more safely and effectively.