Glucose‐Operated Widget (GLOW) for Closed‐Loop Optogenetic Glycemic Control

Closed-loop control systems for precise control of therapeutic gene expression are promising candidates for personalized treatment of chronic ailments such as diabetes. Pancreatic iβ-cells are engineered with blue-light-inducible melanopsin to drive rapid insulin release by vesicular secretion from intracellular stores. In this work, a glucose-operated widget (GLOW) is designed as a component of a closed-loop control system for diabetes treatment by employing a probe that emits blue fluorescence in a glucose-concentration-dependent manner as a real-time glucose sensor to precisely control insulin release from these iβ-cells. As proof-of-concept of the complete control system, the probe is encapsulated together with iβ-cells in alginate-poly-(L-lysine) hydrogel-microbeads(400 µm in diameter and containing about 500 cells) called GLOW