Understanding Shape Manipulation of Polymer Vesicles: a Reactive Dissipative Particle Dynamics Study

Biological cells have long been of interest to researchers due to their ability to actively control their shape. However, the complexity of the process makes it hard to define a deterministic mechanism. Therefore, there is significant interest in mimicking similar behaviors in simplified synthetic systems such as polymer vesicles. Accordingly, we have developed a custom reaction-diffusion model that combines Dissipative Particle Dynamics (DPD) and the Split Reactive Brownian Dynamics (SRBD) that can model the dynamic self-assembling of polymers as they undergo chemical reactions, which expands the capability of simulating the non-equilibrium stochastic behavior of polymer solutions on mesoscopic scales. We first use reactive dissipative particle dynamics (RDPD) to investigate the local shape change driven by either an enzymatically-produced stimulus or microinjection of a stimulus. Our model predicts localized inflation that is induced by either a solvent stimulus that swells the vesicle, or a reactant stimulus that alters the chemistry of the block polymer. Having established this foundation, we use our RDPD simulations to further investigate mechanisms that can induce more complex shape changes and catalytically-driven motion of polymer vesicles.