Regensburg 2019 – wissenschaftliches Programm
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BP: Fachverband Biologische Physik
BP 24: Cell adhesion and migration, multicellular systems I
BP 24.11: Vortrag
Donnerstag, 4. April 2019, 12:30–12:45, H11
Probing the interface structure of adhering cells by contrast variation neutron reflectometry — •Bert Nickel1, Philip Böhm1, Joachim Rädler1, and Erich Sackmann2 — 1Fakultät für Physik & CeNS, Ludwig-Maximilians-Universität, 80539 München — 2Physikdepartment E22, Technische Universität München, 85748 Garching
The cell substrate distance and the amount of water in the membrane substrate gap is difficult to determine. Here, we present a neutron reflectometry study of confluent epithelial cell monolayers on silicon substrates. The neutron experiments have been performed at MLZ in Garching, using MARIA and REFSANS, in collaboration with A. Koutsioubas and J.F. Moulin, respectively. The cell chamber enabled perfusion with cell medium and allowed for contrast variation in-situ by sterile exchange of buffer with different H2O-to-D2O ratio. Contrast variation reduces the ambiguity of data modelling for determining the thickness and degree of hydration of the interfacial cleft between the adherent cells and the substrate. Our data suggest a three-layer interfacial organization. The first layer bound to the silicon surface interface is in agreement with a very dense protein film with a thickness of 10 nm, followed by a highly hydrated 25 nm thick layer, and a several ten nm thick layer attributed to the composite membrane. Hence, the results provide clear evidence of a highly hydrated region between the composite cell membrane and the substrate.