Coarsening Dynamics of Domains in Lipid Membranes

Abstract

We investigate isothermal diffusion and growth of micron-scale liquid domains within membranes of free-floating giant unilamellar vesicles with diameters between 80 and 250 μm. Domains appear after a rapid temperature quench, when the membrane is cooled through a miscibility phase transition such that coexisting liquid phases form. In membranes quenched far from a miscibility critical point, circular domains nucleate and then progress within seconds to late stage coarsening in which domains grow via two mechanisms 1), collision and coalescence of liquid domains, and 2), Ostwald ripening. Both mechanisms are expected to yield the same growth exponent, α = 1/3, where domain radius grows as time(α). We measure α = 0.28 ± 0.05, in excellent agreement. In membranes close to a miscibility critical point, the two liquid phases in the membrane are bicontinuous. A quench near the critical composition results in rapid changes in morphology of elongated domains. In this case, we measure α = 0.50 ± 0.16, consistent with theory and simulation.

RNA transcription modulates phase transition-driven nuclear body assembly

“…Such theories have a long history of application in materials phenomena such as solidification, spinodal decomposition, and the evolution of emulsions and liquid sols (15). Recently, these theories have also been applied to biological phenomena such as compositional domain formation in lipid membranes (16)(17)(18).Here, we investigate the assembly dynamics of nucleoli and "extranucleolar droplets" (ENDs) via a combination of theory, simulation, and experiment. We find that classical models of phase separation and coarsening are sufficient for explaining key features of nucleolar and END assembly dynamics.…”

“…Such theories have a long history of application in materials phenomena such as solidification, spinodal decomposition, and the evolution of emulsions and liquid sols (15). Recently, these theories have also been applied to biological phenomena such as compositional domain formation in lipid membranes (16)(17)(18).…”

Coarsening Dynamics of Binary Bose Condensates

“…The phase ordering dynamics of different systems can thus be separated into distinct dynamical universality classes that are characterized by the dynamical critical exponent z. The concept of scaling applied to the late-time coarsening is truly universal and has found its application to a wide variety of distinct problems in physics: originally developed to describe the growth of metallic grain boundaries [7] and the spinoidal decomposition of a binary alloys below a critical phase-coexistence temperature [8], scaling concepts are now used to describe to formation of galaxies, the domain growth of liquid membranes [9], or even sociopysics [10]. Here, we extend the classical paradigm of phase ordering kinetics to quantum systems by presenting an example of a quantum system that exhibits classical late-time scaling: we calculate the dynamical critical exponent for domain coarsening in a binary superfluid in two dimensions, finding a dynamical scaling exponent that is consistent with inviscid hydrodynamic domain growth.…”

Thermal-driven domain and cargo transport in lipid membranes

“…However, to minimize their edge length, liquid phase domains most commonly form circular patches and coarsen to reduce the overall line energy over the membrane. "Normal" coarsening can occur by collision and coalescence of domains because of their diffusive motion (12,13) or by Ostwald ripening (14). In practice, membrane curvature adds other degrees of freedom and provides another route to minimize the free energy via domain budding (15)(16)(17).…”

“…The behavior of domains in liquid-ordered (Lo)/liquid-disordered (L d ) phase coexistence has been explored in equilibrium and during coarsening (12). Such studies include the fluctuations in the domain boundary observed near Tt (19) and the dependence of Tt on the membrane composition (4).…”