1. Modulation of Vesicle Adhesion and Spreading Kinetics by Hyaluronan Cushions
- Author
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Kheya Sengupta, Laurent Limozin, Limozin, Laurent, Centre de recherche de la matière condensée et des nanosciences (CRMCN), Université de la Méditerranée - Aix-Marseille 2-Université Paul Cézanne - Aix-Marseille 3-Centre National de la Recherche Scientifique (CNRS), Adhésion et Inflammation (LAI), Aix Marseille Université (AMU)-Assistance Publique - Hôpitaux de Marseille (APHM)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Cinam, Hal, and Assistance Publique - Hôpitaux de Marseille (APHM)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)
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congenital, hereditary, and neonatal diseases and abnormalities ,Materials science ,[PHYS.PHYS.PHYS-BIO-PH]Physics [physics]/Physics [physics]/Biological Physics [physics.bio-ph] ,Kinetics ,Biophysics ,Nanotechnology ,02 engineering and technology ,Models, Biological ,03 medical and health sciences ,chemistry.chemical_compound ,Hyaluronic acid ,Microscopy, Interference ,Hyaluronic Acid ,Cell adhesion ,Unilamellar Liposomes ,030304 developmental biology ,chemistry.chemical_classification ,0303 health sciences ,[PHYS.PHYS.PHYS-BIO-PH] Physics [physics]/Physics [physics]/Biological Physics [physics.bio-ph] ,Vesicle ,Molecular Mimicry ,Substrate (chemistry) ,Adhesion ,Polymer ,021001 nanoscience & nanotechnology ,Avidin ,Membrane ,chemistry ,Cell Biophysics ,embryonic structures ,cardiovascular system ,0210 nano-technology - Abstract
The adhesion of giant unilamellar phospholipid vesicles to planar substrates coated with extracellular matrix mimetic cushions of hyaluronan is studied using quantitative reflection interference contrast microscopy. The absolute height of the vesicle membrane at the vicinity of the substrate is measured by considering, for the first time, the refractive indices of the reflecting media. The thickness of the cushion is varied in the range of approximately 50-100 nm, by designing various coupling strategies. On bare protein-coated substrates, the vesicles spread fast (0.5 s) and form a uniform adhesion disk, with the average membrane height approximately 4 nm. On thick hyaluronan cushions (80 nm), the membrane height is approximately the same as the thickness of the cushion, implying that the vesicle lies on top of the cushion. On a thin and inhomogeneous hyaluronan cushion, the adhesion is modified but not prevented. The spreading is slow ( approximately 20 s) compared to the no-cushion case. The average membrane height is approximately 10 nm and the adhesion disk is studded with blisterlike structures. Observations with fluorescent hyaluronan indicate that the polymer is compressed under, rather than expelled from, the adhesion disk. The adhesion energy density is approximately threefold higher in the no-cushion case (1.2 microJ/m(2)) as compared to the thin-cushion case (0.54 microJ/m(2)). In the thin-cushion case, the presence of short ( approximately 4 nm) glyco-polymers on the vesicles results in a hitherto unreported stable partial adhesion state--the membrane height ranges from zero to approximately 250 nm. The minimal model system presented here mimics in vitro the hyaluronan-modulated early stages of cell adhesion, and demonstrates that the presence of a polymer cushion influences both the final equilibrium adhesion-state and the spreading kinetics.
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