Single polymer dynamics of topologically complex DNA

Single molecule studies allow for the direct observation of polymer dynamics in dilute and concentrated solutions, thereby revealing polymer chain conformations and molecular sub-populations that may be obscured in ensemble-level measurements. Over the past two decades, researchers have used DNA as a model system to study polymer dynamics at the molecular level. The vast majority of studies have focused on linear DNA molecules; however, researchers have recently begun to study polymers with complex topologies and architectures at the single molecule level. Here, we explore recent work in single polymer dynamics focused on topologically complex DNA, including knots, ring polymers, and branched polymers. Experimental, computational, and theoretical advances have enabled in-depth studies of topologically complex DNA, with recent efforts focused on complex molecular conformations, intermolecular interactions, and topology-dependent dynamics. In this article, we highlight recent work aimed at understanding the interplay between molecular-scale behavior and the emergent properties of polymeric materials.