Regensburg 2004 – scientific programme

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AKB: Biologische Physik

AKB 50: Poster Session "Biological Physics"

AKB 50.51: Poster

Friday, March 12, 2004, 10:30–13:00, B

Studying cell adhesion with holographic optical tweezers — •Jennifer E. Curtis and Joachim P. Spatz — Biophysical Chemistry, Institiute for Physical Chemistry, University of Heidelberg

Most cells must adhere to a surface if they are to survive. Cell adhesion involves the orchestration of a stunning number of proteins to form focal complexes, the physical link between the surface, plasma membrane, and the stabilizing cytoskeleton. Despite this complexity, simple mechanical force plays a unique role in the initiation of cell adhesion. The activities of cells depend sensitively on the mechanical nature of their adhesion substrate. When too soft, a cell cannot adhere and focal contacts fail to form. When too hard, unphysiological actin stress fibers plague the cell. Using holographic optical tweezers, we present dozens of microspheres directly above the surface of a fibroblast to study the dynamics of focal adhesion formation. We also study how the initial position and the force exerted by the optical traps influences the final binding strength, the total time for full binding, and the subsequent motion of the bead. Lastly, we hope to elucidate the role of the hylauronic acid layer in focal adhesion by studying binding dynamics with and without this sticky sugar matrix.