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SYBM: Physik biologischer Materie

SYBM 401: Physics of biological matter: Poster

SYBM 401.42: Poster

Tuesday, March 12, 2002, 18:00–19:30, H37

Strain Field Mapping of the Cell Membrane of Endothelial Cells — •Wolfgang Feneberg and Erich Sackmann — Institut für Biophysik E22, Technische Universität München

We applied a recently developed magnetic bead micro-rheometer (Magnetic Tweezers) to investigate the influence of actin on the properties of the cell membrane of endothelial cells (HUVEC). We coated superparamagnetic beads of a diameter of 4.5 µm with different integrin-binding proteins (e.g. fibronectin, collagen IV, invasin) and thus linked them to the actin cortex. Via an external magnetic coil we can apply forces of up to 5 nN to these beads. The displacement is measured in real time with framerates of 100 Hz by a single particle trecking algorithm. With this setup we can test the influence of drugs and enzyms (e.g. thrombin, histamine, LPA) on the viscoelastic properties of the actin cortex. For an additional characterisation of the properties of the actin cortex we additionally analyze the strain field, which we visualize by non-magnetic beads attached to the cell membrane.