Berlin 2015 – wissenschaftliches Programm

Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe

BP: Fachverband Biologische Physik

BP 16: Posters: Cell adhesion, mechanics and migration

BP 16.16: Poster

Montag, 16. März 2015, 17:30–19:30, Poster A

Early cell adhesion on hydrogels with graded stiffness and ligand affinity — •Christina Müller and Tilo Pompe — Universität Leipzig, Institut für Biochemie, Johannisallee 21-23, 04103 Leipzig

Mechanotransduction is known as one control mechanism for several basic cell functions, like proliferation, differentiation and cell death. For a better understanding of mechanotransduction, we investigated early cell adhesion on hydrogels with an independent variation of substrate stiffness and affinity of adhesion ligands to the hydrogel surface. Thin film coatings of maleic acid copolymers on top of polyacrylamide hydrogel layers were fabricated to tune protein binding to the hydrogel surface. The stiffness of the hydrogel was modulated between 2.5 kPa and 9 kPa. Human umbilical vein endothelial cells were monitored during the first two hours of cell adhesion by time-resolved cell traction force microscopy. Three different regimes of traction force generation were found. In the first regime (R0) cells spread fast, but traction forces were negligibly small. In the second regime (R1) spreading slowed down and traction forces increased until they saturated in the last regime (R2). The force curve characteristics, for instance the slope in R1 and the saturation force in R2 were substrate-dependent. From 2.5 kPa to 5 kPa both parameters showed a tremendous increase and leveled off for 9 kPa hydrogels. For the two polymer coatings an offset in the averaged forces additive to the stiffness dependence could be observed in positive correlation to protein affinity to the substrate surface. These results can be interpreted as a superposition of conservative and dissipative processes in cell adhesion.