Biomimetic-engineered poly (ethylene glycol) hydrogel for smooth muscle cell migration

We report on a biomimetic scaffold as a model system to evaluate smooth muscle cell (SMC) migration in three dimensions. To accomplish this, bio-inert poly (ethylene glycol) (PEG)-based hydrogels were designed as the scaffold substrate. To mimic properties of the extracellular matrix, cell-adhesive peptide (GRGDSP) derived from fibronectin and collagenase-sensitive peptide (GPQGIAGQ) derived from collagen type I were incorporated into the PEG macromer chain. Copolymerization of the biomimetic macromers results in the formation of bioactive PEG hydrogels with cell adhesivity and biodegradability. By utilizing these biomimetic scaffolds, we studied the effect of adhesive ligand concentration, proteolysis, and network cross-linking density on cell migration. Our results showed that three-dimensional SMC migration has a biphasic dependence on adhesive ligand density, and both adhesive and collagenase-sensitive peptides were required for cell migration to occur. Furthermore, network cross-linking density was shown to dramatically influence the behavior of cell migration in the hydrogels.