Dresden 2017 – scientific programme

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BP: Fachverband Biologische Physik

BP 21: Posters - Membranes and Vesicles

BP 21.9: Poster

Tuesday, March 21, 2017, 14:00–16:00, P1A

Biological Signaling by Sound. A Physics Approach. — •Carina Fedosejevs and Matthias Schneider — TU Dortmund, Germany

Lipid bilayers build up all biological interfaces in cells. We study the prediction that perturbations can propagate and have characteristics of acoustic waves. These perturbations can be local changes of parameters like pH, temperature or density. The pulses increase also the activity of embedded enzymes during their propagation. We examine whether these acoustic pulses can explain how intercellular communication happens. For lipid monolayers this is already proven. Here we attempt to study the propagation in bi-/ multilayers because of their biological relevance. To measure these pulses a Langmuir Trough is used with two pressure sensors holding a Wilhelmy Plate. With the Langmuir-Blodgett Technique lipid layers are transferred onto a glass slide. The bi-/multilayer results by connecting the slide to the monolayer on the subphase. The excitation happens with the embedding of e.g. ethanol molecules in the layer, which causes a local density change. Pulses were measured in bilayers for different phospholipids in varied phase states. By using more layers a correlation between number of layers and velocity is expected. Additionally the lipid dynamics on the glass slide are investigated with fluorescence measurements. A correlation between diffusion velocity in the outer layer and number of layers could show the influence of the glass slide in the experiments. We could prove that our assumptions are also true for lipid bilayers, which is an important step transferring this theory to the living system of cells.