Abstract:A self-repairing ability of phospholipid monolayers deposited onto thin hydrogel films was observed by fluorescence microscopy, in terms of the expansion and lateral spreading of the monolayer into film defects. The spreading was quantitatively analyzed by covering half of a substrate supporting a thin hydrogel film with a lipid monolayer by Langmuir-Blodgett transfer and observing the spreading of the initially confined monolayer at increased relative humidities due to the hydration of both lipid headgroups a… Show more
“…1 This edge roughening is in contrast to monolayer spreading on the same substrates, where no significant line roughening was observed. 60 The fact that no spreading of bilayers on agarose films was observed can, according to eq 1, be explained by a small energy gain by bilayer spreading W A , which is in accordance with the results from LB-trough experiments and RICM. However, the impossibility of bilayer spreading on agarose cushions could also be due to a high drag coefficient ζ on agarose films.…”
Section: Discussionsupporting
confidence: 87%
“…Such a roughening was also found in the case of spreading on glass surfaces and was attributed to line pinning, induced by the substrate roughness . This edge roughening is in contrast to monolayer spreading on the same substrates, where no significant line roughening was observed …”
Bilayer lipid membranes were deposited onto two different thin water swellable polymer cushions predominantly by Langmuir-Blodgett trough methods. Membranes consisting of zwitterionic lipids supported by agarose films were shown to be unstable, as observed by fluorescence microscopy, reflection interference contrast microscopy, and the impossibility of bilayer spreading (Rä dler, J.; Strey, H.; Sackmann, E. Langmuir 1995, 11, 4539-4548) on the agarose surface. Chitosan, formerly observed to permanently coat liposome surfaces of zwitterionic lipid membranes (Henriksen, I.; Smistad, G.; Karlsen, J. Int. J. Pharm. 1994, 101, 227-236), was used to prepare thin films by spin-coating and was found to sufficiently adsorb and thereby stabilize planar bilayer lipid membranes. Bilayer spreading on a chitosan surface was observed, indicating the self-healing ability of chitosan-supported lipid membranes.
“…1 This edge roughening is in contrast to monolayer spreading on the same substrates, where no significant line roughening was observed. 60 The fact that no spreading of bilayers on agarose films was observed can, according to eq 1, be explained by a small energy gain by bilayer spreading W A , which is in accordance with the results from LB-trough experiments and RICM. However, the impossibility of bilayer spreading on agarose cushions could also be due to a high drag coefficient ζ on agarose films.…”
Section: Discussionsupporting
confidence: 87%
“…Such a roughening was also found in the case of spreading on glass surfaces and was attributed to line pinning, induced by the substrate roughness . This edge roughening is in contrast to monolayer spreading on the same substrates, where no significant line roughening was observed …”
Bilayer lipid membranes were deposited onto two different thin water swellable polymer cushions predominantly by Langmuir-Blodgett trough methods. Membranes consisting of zwitterionic lipids supported by agarose films were shown to be unstable, as observed by fluorescence microscopy, reflection interference contrast microscopy, and the impossibility of bilayer spreading (Rä dler, J.; Strey, H.; Sackmann, E. Langmuir 1995, 11, 4539-4548) on the agarose surface. Chitosan, formerly observed to permanently coat liposome surfaces of zwitterionic lipid membranes (Henriksen, I.; Smistad, G.; Karlsen, J. Int. J. Pharm. 1994, 101, 227-236), was used to prepare thin films by spin-coating and was found to sufficiently adsorb and thereby stabilize planar bilayer lipid membranes. Bilayer spreading on a chitosan surface was observed, indicating the self-healing ability of chitosan-supported lipid membranes.
“…Recently, Baumgart and Offenhäuser have described complementary experiments on the lateral spreading of substrate-supported lipid monolayers that revealed quite different spreading behavior . Langmuir−Blodgett (LB) monolayers of phospholipids were deposited onto thin, water-swellable polysaccharide films spin-coated onto glass.…”
Section: Introductionmentioning
confidence: 99%
“…There was no evidence of the t 1/2 dependence found for precursor films and also for lipid bilayers spreading from a reservoir; nevertheless, it is still possible that t 1/2 dependence might have been found had the experiments been extended to longer times and greater distances. 1 Data of Baumgart and Offenhäuser . Spreading dynamics at 90% RH of a DMPC monolayer transferred at a pressure of 20 mN/m onto a thin film of chitosan.…”
Using large-scale molecular dynamics simulations, we have shown previously that the spreading dynamics of sessile drops on solid surfaces can be described in detail using the molecular-kinetic theory of dynamic wetting. Here we present our first steps in extending this approach to investigate the spreading dynamics of Langmuir-Blodgett monolayers. We make use of a monolayer model originally developed by Karaborni and Toxvaerd, but somewhat simplified to facilitate large-scale simulations. Our preliminary results are in good agreement with recent experimental observations and also support a molecular-kinetic interpretation in which the driving force for spreading is the lateral pressure in the monolayer. Away from equilibrium, initial spreading rates are constant and logarithmically dependent on pressure. However, near equilibrium, spreading is pseudo-diffusive and follows the square root of time. In both regimes the controlling factor is the equilibrium frequency of molecular displacements within the monolayer.
“…Perhaps most noteworthy, cushioned systems have been fabricated with the polysaccharide chitosan [254]. Chitosan is easily prepared in an aqueous solution and has been demonstrated to make very controllable and high quality thin films via spin coating [275]. …”
Section: Model Membrane Systems To Study the Nonclassical Protein mentioning
Extracellular proteins devoid of signal peptides use nonclassical secretion mechanisms for their export. These mechanisms are independent of the endoplasmic reticulum and Golgi. Some nonclassically released proteins, particularly fibroblast growth factors (FGF) 1 and 2, are exported as a result of their direct translocation through the cell membrane. This process requires specific interactions of released proteins with membrane phospholipids. In this review written by a cell biologist, a structural biologist and two membrane engineers, we discuss the following subjects: (i) Phenomenon of nonclassical protein release and its biological significance; (ii) Composition of the FGF1 multiprotein release complex (MRC); (iii) The relationship between FGF1 export and acidic phospholipid externalization; (iv) Interactions of FGF1 MRC components with acidic phospholipids; (v) Methods to study the transmembrane translocation of proteins; (vi) Membrane models to study nonclassical protein release.
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