System for the Application of Hydrostatic Pressure and Mechanical Strain to Cell Cultures

Pressure and stretch are two of the primary forces thatresult in mechanotransductory eventswhichregulatecertainaspects ofhuman health and disease. Laboratory systems such as the commercially available Flexercell® system and a variety of custom-made setups are currently used in research to systematically apply stretch and hydrostatic pressure independently, or in conjunction to cell and tissue cultures. However, these systems do not allow for the decoupling of pressure and stretch under the same culture conditions. The present study aims to design, fabricate, and calibratea device that can apply pressure and stretch simultaneously, as well as independently to cells in culture. Moreover, in order to characterize the mechanical behaviorof the cell substrate, equibiaxial mechanical testing was conducted on the substrate and the resulting data wereused to generate a finite element simulation of the device. Moreover, an analytical approach was used in an attempt to validate the simulation. To our knowledge, this is the first system that can definitively distinguish between the mechanotransductive events activated in response to pressure and stretch. Using this novel device, MYP3 cells cultured onfibronectin-coated substrates were exposed to pressure and stretch, together or independently. The cells exhibited the morphology characteristic of healthy urothelialcells. The extracellular ATP data indicated an increase in ATP release in response to mechanical stimuli. Caspase-1 activity decreased in response to mechanical stimuli. The present study was successful in creating a unique device capable of applying pressure and stretch, together and independently, to cells in culture to allow examination of the relative contributions of these stimuli in various mechanobiological events.