Abstract: The present invention relates generally to vesicles such as liposomes, colloidosomes, and polymersomes, as well as techniques for making and using such vesicles. In some cases, the vesicles may be at least partially biocompatible and/or biodegradable. The vesicles may be formed, according to one aspect, by forming a multiple emulsion comprising a first droplet surrounded by a second droplet, which in turn is surrounded by a third fluid, where the second droplet comprises lipids and/or polymers, and removing fluid from the second droplet, e.g., through evaporation or diffusion, until a vesicle is formed. In certain aspects, the size of the vesicle may be controlled, e.g., through osmolarity, and in certain embodiments, the vesicle may be ruptured through a change in osmolarity. In some cases, the vesicle may contain other species, such as fluorescent molecules, microparticles, pharmaceutical agents, etc., which may be released upon rupture.