Measuring cell adhesion forces during the cell cycle by force spectroscopy

Abstract

Force spectroscopy has been used to measure the adhesion of Saos-2 cells to a glass surface at different phases of the cell cycle. The cells were synchronized in three phases of the cell cycle: G 1 , S, and G 2 M. Cells in these phases were compared with unsynchronized and native mitotic cells. Individual cells were attached to an atomic force microscope cantilever, brought into brief contact with the glass surface, and then pulled off again. The force-distance curves obtained allowed the work and maximum force of detachment as well as the number, amplitude, and position of discrete unbinding steps to be determined. A statistical analysis of the data showed that the number of binding proteins or protein complexes present at the cell surface and their binding properties remain similar throughout the cell cycle. This, despite the huge changes in cell morphology and adhesion that occur as the cells enter mitosis. These changes are rather associated with the changes in cytoskeletal organization, which can be quantified by force spectroscopy as changes in cell stiffness.

Determinants of cell–material crosstalk at the interface: towards engineering of cell instructive materials

“…Atomic force microscopes equipped with specifically designed tips have been variously used to detect the force to dislodge or to stretch cells. Depending on the substrate properties and cell type, detachment forces of the order of 10-100 nN (cell dislodging) or 0.1-1 nN (cell stretching) have been reported [13,14]. Similar results were obtained by means of micropipettes.…”

Regulation of Endothelial Cell Adherence and Elastic Modulus by Substrate Stiffness

“…The maximum force of detachment has been considered as a dependent parameter, which is related to the number and amplitude of unbinding events (Weder et al 2009) due to molecular bonds breakage (Friedrichs et al 2010). Detachment work also depends on the number, amplitude, and position of unbinding events (Weder et al 2009). Here, the lowest value of this parameter was corresponding to the soft substrate which indicates the least cell adherence on the soft gel.…”

“…The retract curve (grey curve in Figure 1) (Retraction part 1) contains several information about cell-substrate adhesion, including maximum detachment force which is related to the number and amplitude of the unbinding events (Weder et al 2009), detachment work which is the required work for detaching cell from the surface and is related to the number, amplitude, and the position of unbinding events during cantilever retraction (Weder et al 2009), as well as unbinding force of molecular bonds. Finally, there is no more cell-surface contact (Retraction 2).…”

Dynamic cell adhesion and migration on nanoscale grooved substrates

“…Adhesion of the cell adhered to the cantilever to the different nanostructures was subsequently measured by bringing the cell into contact with the substrate with a contact force of 1000 pN and allowing the cell to adhere for 10 s. Subsequently, the cell was retracted at a retraction speed at 12 μm/s, with subsequently a relaxing time of 2 s to give the cell time to recover ( Fig. 2b) (Friedrichs et al, 2010;Weder et al, 2009). Cell adhesion experiments were performed in either 10 % serum, 1 % serum, or in serumfree conditions.…”