Preparation of a Novel Glucose Responsive Worm-like Micelle Gel with Phenylboronic Acid and Evaluation of Its Drug Release

Abstract

We prepared a novel glucose-responsive gel formed by worm-like micelles (WLMs), which has the potential to provide a self-regulating insulin delivery system. We used 75 mM cetyltrimethyl-ammonium bromide, 75 mM phenylboronic acid, and water to prepare the gel. At pH 9.4, the system was highly viscous and supported its own weight, and dynamic viscoelasticity measurement indicated that it contained long and entangled WLMs. The visual observation revealed that the gel with 10 mM glucose changed to sol-like appearance, whereas those prepared to include a control compound (10 mM diethylene glycol) retained their gel-like appearance. In vitro release was evaluated using a test compound (fluorescein isothiocyanate dextran) in a microsized flow system. By 120 min, the release of this compound from the WLM gel was around 27-fold greater in the presence of 100 mM glucose than with 100 mM diethylene glycol. This demonstrated the successful preparation of a WLM gel that showed an altered drug release rate, depending on glucose.