Cell adhesion and detachment on gold surfaces modified with a thiol-functionalized RGD peptide.

The dynamic nature of cell adhesion and detachment is critically important to a variety of physiological and pathophysiological phenomena. Much, however, still remains uncertain and controversial about the mechanochemical players and processes involved in cellular adhesion and detachment. This leads to the need for quantitative characterization of the adhesion and detachment of anchorage-dependent cells. Here, cell adhesion and detachment up to subcellular level are examined using gold surfaces modified with a thiol-functionalized arginine-glycine-aspartic acid (RGD) peptide. A thiol self-assembled monolayer (SAM) on top of the gold surfaces is reductively desorbed with activation potential to spatiotemporally manipulate both cell adhesion and detachment. This method maintains cells of interest living and intact during experiments, making it possible to quantify cell adhesion and detachment as close as possible to in vivo conditions. Experimental characterizations for NIH 3T3 fibroblasts are carried out with a focus on the following issues: the effect of the size and geometric shape of gold surfaces on cell adhesion; the effect of cell confluency, cell shape, and activation potential magnitude on cell detachment; changes in the material properties of cells during cell detachment. The findings of this study should lead to better understanding of cellular dynamics in anchorage-dependent cells.