effect of stress-fiber inclusion on the local stiffness of cell cytoskeleton probed by afm indentation: insights from a discrete network model

In this paper, we analyze the effect of stress-fiber inclusion on the stiffness of an actin random network. we use a discrete random network model to analyze the elastic response of this system in terms of apparent young’s modulus. first, we showed that for a flat-ended cylindrical indenter the total indentation force has a linear relation with the indentation depth and the indenter radius. using this relation, we concluded that the stiffening effect of the stress-fiber on the fibrous network has a range of effectivity and surprisingly, the stiffening is not maximum when the stress-fiber is straight below the indenter but when it is a certain distance from it. these results shed light on some aspects of the widely used afm stiffness measurements of cells.