Polymer-induced tubulation in lipid vesicles.
A mechanism of extraction of tubular membranes from a lipid vesicle is presented. A concentration gradient of anchoring amphiphilic polymers generates tubes from budlike vesicle protrusions. We explain this mechanism in the framework of the Canham-Helfrich model. The energy profile is analytically calculated and a tube with a fixed length, corresponding to an energy minimum, is obtained in a certain regime of parameters. Further, using a phase-field model, we corroborate these results numerically. We obtain the growth of tubes when a polymer source is added, and the budlike shape after removal of the polymer source, in accordance with recent experimental results.
Departament d'Estructura i Constituents de la Matèria, Facultat de Física, Universitat de Barcelona, Diagonal 647, Barcelona, Spain. campelo@ecm.ub.es
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Campelo
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Hernández-Machado
D008051:Lipid Bilayers / Q000737:chemistry*; D008956:Models, Chemical; D011108:Polymers / Q000737:chemistry*
D008051:Lipid Bilayers; D011108:Polymers