Light-responsive microneedle array with tunable insulin release function for painless and on-demand anti-diabetic therapy

Diabetes is a chronic disease with a high incidence that requires persistent therapy with accurate drug administration. We report a near-infrared light-responsive microneedle with tunable insulin supply for painless and on-demand anti-diabetes therapy. It comprises of a calcium alginate frame having near-infrared radiation-responsive polydopamine-coated poly-lactic-co-glycolic acid microspheres serving as a capsule for insulin on the frame. The microneedle initiated and stopped insulin release via a light triggered on–off mechanism. In vivo experiments revealed that our microneedle provided an appropriate dose of insulin in conformity with the daily blood glucose fluctuations to precisely maintain the blood glucose levels for a long period. These findings suggest the efficacy and safety of the developed microneedle for anti-diabetic therapy.