Probing cell structure by controlling the mechanical environment with cell-substrate interactions

Recent results demonstrate the exquisite sensitivity of cell morphology and structure to mechanical stimulation. Mechanical stimulation is often coupled with cell-substrate interactions that can, in turn, influence molecular response and determine cellular fates including apoptosis, proliferation, and differentiation. To understand these effects as they specifically relate to compressive mechanical stimulation and topographic control, we developed a microfabricated system to grow cells on polydimethylsiloxane (PDMS) microchannel surfaces where we maintained compression stimulation. We also probed cellular response following compressive mechanical stimulation to PDMS substrates of varying stiffness. In these instances, we examined cytoskeletal and morphologic changes in living cells attached to our substrate following the application of localized compressive stimulation. We found that the overall morphology and cell structure, including the actin cytoskeleton, oriented in the direction of the compressive strain applied and along the topographic microchannels. Furthermore by comparing topographic response to material stiffness, we found a 40% increase in cell area for cells cultured on the microchannels versus softer PDMS as well as a decreased cell area of 30% when using softer PDMS over unmodified PDMS. These findings have implications for research in a diversity of fields including cell-material interactions, mechanotransduction, and tissue engineering.