Non-pulsatile lipid vesicles under osmotic stress

Understanding the physical mechanisms governing vesicle responses under osmotic imbalance is crucial for not only advancing knowledge of the osmoregulatory mechanisms of living cells, but also constraining design choices in biocompatible micro-solute transportation systems, and multicompartment microreactors. When placed under osmotic stress, vesicle response will diverge across one of three trajectories: simple engorgement, swelling with eventual pore formation, and irreversible explosion. In this talk, we present a comprehensive theoretical model that unifies these behavioral outcomes based on fundamental properties of the lipid membrane. We demonstrate how sudden osmotic shock, such as through light-triggered reactions, can lead to explosion, and outline key conditions that determine explosion or swell-burst-reseal dynamics. We expand this understanding by presenting recent advances for the phase diagram of vesicle fates. With this, the previously unappreciated contribution of membrane bending energy emerges as a significant determiner of mechanical response. This talk situates this energy contribution within the broader context of vesicle dynamics and helps in advancing a fundamental understanding of vesicle response in non-equilibrium environments.