A Method to Determine the Effect of Stiffness and Stretch on Cell Phenotype

Cells have the ability to sense their mechanicalenvironment and respond by altering their adhesion, proliferation, locomotion, and morphology. In order to elucidatethe interrelated effects of different mechanical stimuli on cellphenotype in vitro, we have developed a method for culturingmammalian cells in a two-dimensional environment at variouslevels of substrate stiffness and equibiaxial stretch. Polydimethylsiloxane was polymerized on flexible siliconemembranes at different levels of stiffness. The membranes werethen stretched equibiaxially using a commercially availablesystem. Image analysis was used to verify the uniformity of thestrain field applied to the cells. Microscopic analysis of stretchedand static samples showed low initial cell attachment; however, both static and stretched samples retained cells with 87% and83% viability, respectively. We are currently investigating the combined effects of substrate stiffness and stretch onvalvular interstitial cell phenotype, as the phenotype ofthese cells influences the function of heart valves [1-3].