Effect of Force-dependent Unbinding Kinetics on the Self-Assembly of DNA-Coated Emulsion Droplets

Micron-sized emulsion droplets coated with mobile DNA linkers can self-organize into predetermined structures by appropriate control of the droplet valence. Our coarse-grained molecular dynamics simulation model is designed to study the phenomenon of self-assembly of these droplets. A crucial piece of our model is specific one-to-one dynamic bonding between coarse-grained beads representing DNA. We previously designed the model so that the kinetics includes temperature-dependent rates, in order to appropriately represent DNA melting. But we also know that mechanical forces can play a role in governing the lifetime of molecular interactions. Here, we introduce different models of force dependent kinetics into our dynamic bonding model. We then explore how the force-dependent unbinding rates affects the valence of these emulsion droplets. Also, we show how the force-dependent unbinding governs the kinetics of growth of the "adhesion patch" formed between two droplets (by recruitment of the DNA linkers) as well as the size of the adhesion patch.