Multifunctional Tyrosine-Derived Polycarbonates: Effect of Chemistry on Smooth Muscle Cell Adhesion and Motility

The performance of blood-contacting implants and vascular tissue engineering scaffolds depends heavily on the regulation of vascular cell responses. The goal of this study was to examine underlying substrate-smooth muscle cell responses, using a library of multifunctional, tyrosine-derived polycarbonates. Three chemical components within the polymer structure were selectively varied through copolymerization: 1) the content of iodinated tyrosine to achieve X-ray visibility; 2) the content of poly(ethylene glycol) (PEG) to decrease protein adsorption and cell adhesivity; and 3) the content of desaminotyrosyl-tyrosine (DT) which regulates the rate of polymer degradation. We quantified differential serum protein adsorption behavior due to the chemical components DT, iodinated tyrosine, and PEG using quartz crystal microbalance with dissipation. The complex interplay of the polymer components was tested on the adhesion, proliferation, and motility behavior cultured human aortic smooth muscle cells. The incorporation of PEG into the polymer reduced cell attachment, which was reversed in the presence of iodinated tyrosine. Further, we found that as little as 10% DT content was sufficient to negate the PEG effect in polymers containing iodinated tyrosine while in non-iodinated polymers the PEG effect on cell attachment was reversed. Cross-functional analysis of motility and proliferation revealed divergent substrate chemistry related cell response regimes. Additionally, our data suggests unique biorelevant properties following the incorporation of iodinated subunits in a polymeric biomaterial as a potential platform for X-ray visible devices.