Effects of Mechanical Stimulus on Cells Via Multi-Cellular Indentation Device

Abstract

Mechanical as well as chemical stimulations are considered as a critical factor on cell behaviors. To understand the effects of mechanical stimuli on cells, many researchers have developed either single cell indentation devices to locally stimulate cells or to measure mechanical properties of cells, or compression chambers or bioreactors to apply global compressive pressure on cells. However, none of these previously developed devices are suitable to investigate the cell-cell communications amongst cells upon mechanical stimulation. To accomplish this experimental need, we developed a new cellular compression device using soft-lithography techniques. We fabricated the chamber with transparent Poly-carbonate, which consists of two sections, a self-contained cell incubator and an air chamber, separated by a PDMS membrane. On an incubator side of this PDMS divider, we attach a patterned PDMS sheet of micro poles mounted on a glass to ensure a uniform displacement of the array of poles to stimulate cells when the air chamber is pressurized. The cell incubator chamber is filled with medium and connected to a self contained incubation system to supply fresh culture medium to cells providing a stable culture environment during the experiments. The operating power is an air pressure applied on the air chamber side of the PDMS membrane. By controlling the air pressure, this device can stimulate cells in cyclic or continuous conditions. Also as cells are cultured in a form of single layer, it allows us to investigate cell-cell communications amongst cells that are under stimulated or non-stimulated conditions. Using this noble device, we investigated protein responses in keratinocytes, one of the mechano-sensitive cells. Preliminary results have shown the versatility of this compression device in studying cellular responses, thus demonstrating the feasibility of this tool as to be utilized in evolving cell mechanics research. © 2009 International Federation of Medical and Biological Engineering.