The role of particle shape in the deformation and disruption of lipid membranes : Experiments with tunable particle shape and adhesion

We seek to understand the effects of DNA origami nano-rods on membrane structure and morphology. We combine giant unilamellar lipid vesicles (GUVs) with a sufficiently high concentration of oppositely charged nano-rods and observe the interactions. The adhesion of the nano-rods to the membrane is a tunable parameter controlled by the lipid composition, and results in three primary behaviors. At weak adhesion strengths, vesicles adhere to one another and form a stable gel, with the nano-rods acting as a glue that holds the gel together. At intermediate adhesion strengths, gel forms but is subsequently destroyed by avid binding of the nano-rods. At higher adhesion strengths, the vesicles are ruptured by the nano-rods without ever forming a gel. These behaviors can be explained respectively by shallow, deep, or complete wrapping of the nano-rods onto the lipid membrane. These results are a robust example of tuning response in a synthetic membrane system and provide a physical understanding of the design principles toward controlled membrane morphologies. These results will lead to a bio-inspired membrane material that is stimuli-responsive, has high surface area and is reconfigurable.