Photo-induced asymmetric oxidation causes vesicle explosion

Oxidation of lipids by reactive oxygen species alters their structural properties, compromising cell membrane integrity and disrupting homeostasis and biological functions in living cells, and even causing cell death. Oxidation of a model membranes employing giant unilamellar vesicles, leads to the formation of a series of short-lived pores as well as sudden total catastrophic loss of membrane stability (i.e., vesicle explosion). However, the physical mechanism as to how oxidized lipids cause vesicles explosion is still unknown. In this poster, we investigate the process of the mechanical response in lipid vesicles to photoinduced oxidative stress. Through experiments and theoretical modeling, we demonstrate key role of spontaneous curvature in causing vesicle explosion. Accounting for role of spontaneous curvature and curling instability, we propose a model of the pore-opening dynamics, which captures the experimental observations reasonably well. Finally, we show temporal evolution of spontaneous curvature during oxidation and conclude with a phase diagram delineating formation of transient pores and vesicle explosion. Our results provide insights on the stability of biological cells in oxidative environment and to aide in strategizing and fine-tuning release dynamics of vesicle-based precision delivery systems.