(443e) The Relative Impact of Scaffold Modulus Versus Applied Strain On Smooth Muscle Cell Behavior

Over the past decade, tissue engineered vascular grafts (TEVGs) have emerged as potential replacements for small diameter blood vessels. Recent literature indicates that scaffold modulus critically influences smooth muscle cell (SMC) behavior under static culture conditions. Thus, a number of studies are currently being performed to optimize the modulus of TEVGs scaffolds so as to elicit desired cell ECM deposition prior to implantation. However, little work has been done to determine whether scaffold modulus is a significant regulator of cell response under physiological (dynamic culture) conditions. The present study was designed to evaluate the influence of scaffold modulus relative to applied mechanical strain on SMC extracellular matrix deposition and phenotype. Tubular scaffolds of distinct moduli (60 kPa and 300 kPa) but with similar mesh sizes and bioactivity levels were prepared using diacrylate derivatized poly(ethylene glycol) (PEGDA). For each scaffold modulus group, two distinct cyclic strain conditions (5% and 10%) were applied using a pulsatile bioreactor. After 7 days of mechanical conditioning, constructs were harvested and biochemically and histologically analyzed. Comparison among the four modulus-strain treatment groups indicated that applied strain dominated cell responses, suggesting that applied strain may have greater influence on SMC behavior than scaffold modulus.