Hemocompatibility evaluation of poly(glycerol-sebacate) in vitro for vascular tissue engineering

Poly(glycerol-sebacate) (PGS) is an elastomeric biodegradable polyester that could potentially be used to engineer blood vessels in vivo. However, its blood-material interactions are unknown. The objectives of this study were to: (a) fabricate PGS-based biphasic tubular scaffolds and (b) assess the blood compatibility of PGS in vitro in order to get some insight into its potential use in vivo. PGS was incorporated into biphasic scaffolds by dip-coating glass rods with PGS pre-polymer. The thrombogenicity (platelet adhesion and aggregation) and inflammatory potential (IL-1beta and TNFalpha expression) of PGS were evaluated using fresh human blood and a human monocyte cell line (THP-1). The activation of the clotting system was assessed via measurement of tissue factor expression on THP-1 cells, plasma recalcification times, and whole blood clotting times. Glass, tissue culture plastic (TCP), poly(l-lactide-co-glycolide) (PLGA), and expanded polytetrafluorethylene (ePTFE) were used as reference materials. Biphasic scaffolds with PGS as the blood-contacting surface were successfully fabricated. Relative to glass (100%), platelet attachment on ePTFE, PLGA and PGS was 61%, 100%, and 28%, respectively. PGS elicited a significantly lower release of IL-1beta and TNFalpha from THP-1 cells than ePTFE and PLGA. Similarly, relative to all reference materials, tissue factor expression by THP-1 cells was decreased when exposed to PGS. Plasma recalcification and whole blood clotting profiles of PGS were comparable to or better than those of the reference polymers tested.