Biomedical nanomotors: efficient glucose-mediated insulin release

We report herein the design of an autonomous glucose-responsive smart nanomachine for insulin (In) delivery based on ultrasound (US)-propelled nanomotors combined with an enzyme-based sensing-effector unit. Gold nanowire (AuNW) motors have been coupled with a mesoporous silica (MS) segment, which was gated with pH-responsive phenylboronic acid (PBA)-glucose oxidase (GOx) supramolecular nanovalves responsible for the insulin release. Glucose-induced protonation of the PBA groups triggers the opening of the pH-driven gate and uncapping of the insulin-loaded nanovalves. The insulin-loaded MS-Au nanomotors displayed an efficient US-driven movement that dramatically accelerates the glucose-triggered insulin release when compared to their static counterparts. Such coupling of the locomotion of nanovehicles with gated insulin-containing nanocontainers and glucose-responsive nanovalves holds great promise for the improved management of diabetes.