title: Spontaneous vesicle formation at lipid bilayer membranes.
abstract: Unilamellar vesicles are observed to form spontaneously at planar lipid bilayers agitated by exothermic chemical reactions. The membrane-binding reaction between biotin and streptavidin, two strong transmembrane neutralization reactions, and a weak neutralization reaction involving an "antacid" buffer, all lead to spontaneous vesicle formation. This formation is most dramatic when a viscosity differential exists between the two phases bounding the membrane, in which case vesicles appear exclusively in the more viscous phase. A hydrodynamic analysis explains the phenomenon in terms of a membrane flow driven by liberated reaction energy, leading to vesicle formation. These results suggest that energy liberated by intra- and extracellular chemical reactions near or at cell and internal organelle membranes can play an important role in vesicle formation, membrane agitation, or enhanced transmembrane mass transfer.
authors.affiliation: Department of Chemical Engineering, Pennsylvania State University, University Park 16802, USA.
authors.forename: D A
authors.initials: DA
authors.lastname: Edwards
authors.forename: F
authors.initials: F
authors.lastname: Schneck
authors.forename: I
authors.initials: I
authors.lastname: Zhang
authors.forename: A M
authors.initials: AM
authors.lastname: Davis
authors.forename: H
authors.initials: H
authors.lastname: Chen
authors.forename: R
authors.initials: R
authors.lastname: Langer
mesh_terms: D001426:Bacterial Proteins / Q000737:chemistry; D055592:Biophysical Phenomena; D001703:Biophysics; D001710:Biotin / Q000737:chemistry; D066298:In Vitro Techniques; D008051:Lipid Bilayers / Q000737:chemistry*; D008854:Microscopy, Electron; D008956:Models, Chemical; D009038:Motion; D010713:Phosphatidylcholines / Q000737:chemistry; D012459:Salicylates / Q000737:chemistry; D020156:Salicylic Acid; D019809:Streptavidin; D013816:Thermodynamics; D014783:Viscosity
chemical_list: D001426:Bacterial Proteins; D008051:Lipid Bilayers; D010713:Phosphatidylcholines; D012459:Salicylates; D001710:Biotin; D019809:Streptavidin; D020156:Salicylic Acid