Strategies in functional poly(ester amide) syntheses to study human coronary artery smooth muscle cell interactions

The design of new generation cardiovascular biomaterials focuses on biomimetic properties that are capable of eliciting specific cellular responses and directing new tissue formation. Synthetic poly(ester amide)s (PEAs) containing α-amino acid residues have the potential to elicit favorable cellular responses. Furthermore, they are biodegradable owing to the incorporation of naturally occurring amino acids. In this study, a family of PEAs was synthesized from selected α-amino acids using both solution and interfacial polymerization approaches to optimize their properties for vascular tissue engineering applications. By careful selection of the monomers and the polymerization approach, high-molecular-weight PEAs with low glass-transition temperatures were obtained. Human coronary artery smooth muscle cells (HCASMCs) cultured directly on bare PEA films attached and spread well up to 7 days of culture. Moreover, cell viability was significantly enhanced on all nonfunctional PEAs compared with tissue culture polystyrene controls. The trifluoroacetic acid salt of the lysine-containing functional PEAs was found to retard cell growth but still supported cell viability up to 5 days of culture. Immunostaining of HCASMCs revealed strong vinculin expression, suggesting that the HCASMCs initiated cellular processes for focal adhesion contacts with all PEA surfaces. Conversely, smooth muscle α-actin expression was not abundant on the PEA surfaces, suggesting a proliferative smooth muscle cell phenotype. Altogether, our results indicate that these PEAs are promising materials for vascular tissue engineering scaffolds.