Ultra-giant lipid vesicles functioning as a centimeter-sized smart chemical reactor

We report a simple and robust method for generating centimeter-sized lipid vesicles (ultra-giant lipid vesicles, UGLVs) by dripping an aqueous solution onto a thin lipid layer floating on the surface of an aqueous phase. A mixture of oleic acid and phospholipids was used to form an interfacial lipid layer. During dripping, the aqueous droplet initially remained above the lipid layer but gradually sank owing to gravity as its volume increased. Once the droplet volume reached several cubic centimeters, it detached from the air-liquid interface and spontaneously formed a stable vesicle with a diameter of several centimeters. Notably, the UGLV remained stable even under mechanical perturbation using a spatula. Furthermore, UGLVs encapsulating the Belousov-Zhabotinsky oscillatory reaction medium were successfully prepared. Neighboring UGLVs exhibit spontaneous synchronization of chemical waves upon contact, demonstrating that UGLVs can function as a unique type of smart chemical reactor.