Figure 5.
Melanoma cells exhibit anisotropic stiffening in the direction of cell migration. (a) Electron micrographs of the cells and attached beads on the cell membrane on flat and grooved substrata. X-axis refers to direction in parallel to grooves, and Y axis refers to the direction perpendicular to the grooves. (b,c) Material properties (stiffness and friction moduli) measured by Magnetic Twisting Cytometry over five decades of probing frequencies in cells cultured on flat (b) and nano-grooved (c) substrata. Data are presented as Geometric Mean ± SE (n = 254–940 individual cells on flat; n = 400–784 individual cells on groove). The solid lines are the fit of experimental data to the structural damping equation with addition of a Newtonian viscous term as previously described55. (d,e) Stiffness measured at 10 Hz, showing anisotropic stiffening of WM35 and 1205Lu cells on the grooves.