Depth matters: cells grown on nano-porous anodic alumina respond to pore depth

Recent experiments have shown unambiguously that living cells respond to the nano-topography of surfaces they grow on—specifically, the fate of stem cells grown on nano-porous titania or alumina have been shown to be decided by the pore size. However, most experiments have focused on pore size or pitch. Here we show that in addition to pore size and pitch, the depth of the pores has a profound effect on cell morphology and the arrangement of the actin cytoskeleton.