Effects of mechanical stimulus on cells via multi-cellular compression device

Abstract

Mechanical as well as chemical stimulations are considered as critical factors on cell behaviors. To understand the effects of mechanical stimuli on cells, many researchers have developed either single cell compression devices to locally stimulate cells and 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 media and connected to a self contained incubation system to supply fresh culture media provide 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 using PID controller, 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 applied compressive stimulation on keratinocytes, which are mechano-sensitive skin epidermal cells. Cellular responses upon compressive stimulation have been investigated in the manner of cell migration, cytoskeleton remodeling and cell proliferation and differentiation. Mechanical compression affects to focal adhesion via changing...