Controlled membrane remodeling by DNA origami nanorods: Experiments targeting the design principles for membrane-based materials

Membrane remodeling facilitated by the self-assembly of proteins on the membrane is essential for cellular function. Inspired by this system, we use DNA origami nanorods to illuminate the role of particle shape and adhesion on membrane reconfiguration. We combine giant unilamellar vesicles with oppositely charged nanorods and observe them with optical and electron microscopy. The binding affinity of the nanorods to the membrane is tunable via lipid composition, which reveals three primary behaviors. For weak particle binding vesicles adhere to one another and form a stable gel. At intermediate binding strengths the gel forms but is subsequently destroyed by avid binding of the nanorods. At higher binding strengths the vesicles rupture without forming a gel. Cryo transmission electron microscopy reveals in-plane ordering of rods on the membrane. These responses are robust and repeatable providing a physical understanding of the dependence on shape, binding affinity and concentration in membrane remodeling. The design principles derived from these experiments will lead to bio-inspired membrane materials that are stimuli-responsive and reconfigurable.