Complex morphologies in lipid membranes typically arise due to chemical heterogeneity, but in the tilted gel phase, complex shapes can form spontaneously even in a membrane containing only a single lipid component. We explore this phenomenon via experiments and coarse-grained simulations on giant unilamellar vesicles of 1,2-dipalmitoyl-sn-glycero-3-phosphocholine. When cooled from the untilted L-alpha liquid-crystalline phase into the L-beta, tilted gel phase, vesicles deform from smooth spheres to disordered, highly crumpled shapes. We propose that this shape evolution is driven by nucleation of complex membrane microstructure with topological defects in the tilt orientation that induce nonuniform membrane curvature. Coarse-grained simulations demonstrate this mechanism and show that kinetic competition between curvature change and defect motion can trap vesicles in deeply metastable, defect-rich structures.
Proceedings of the National Academy of Sciences of the United States of America
Copyright 2013 National Academy of Sciences. Available on publisher's site at http://dx.doi.org/10.1073/pnas.1213994110.
Hirst, Linda S.; Ossowski, Adam; Fraser, Matthew; Geng, Jun; Selinger, Jonathan V.; Selinger, Robin L. B. (2013). Morphology Transition in Lipid Vesicles Due to In-Plane Order and Topological Defects. Proceedings of the National Academy of Sciences of the United States of America 110(9) 3242-3247. doi: 10.1073/pnas.1213994110. Retrieved from https://oaks.kent.edu/cpippubs/365