In vitro physical and biological characterization of biodegradable elastic polyurethane containing ferulic acid for small-caliber vascular grafts

Demand for small diameter vascular grafts is growing. The main limitations of these grafts include induced thrombotic events, lack of in situ endothelialization, intimal hyperplasia and poor mechanical properties which impair the graft patency rate in long-term applications. Most anti-thrombotic modification methods currently in use usually conflict with the formation of an endothelial cell monolayer on the grafts. Here, we synthesized a novel biodegradable poly(ether ester urethane)urea elastomer (PEEUU) using poly(ethylene glycol) and poly(diethylene glycol adipate) as soft segments. To improve hemocompatibility, synthesized PEEUU was blended with ferulic acid (FA). Scanning electron microscopy, water contact angle measurement, and tensile testing were used to characterize the scaffolds. The PEEUU and PEEUU–FA scaffolds revealed appropriate mechanical properties, with tensile strengths and strains similar to a coronary artery. In vitro assay demonstrated that the release of FA from the scaffold is in a sustained manner. Hemocompatibility tests indicated that the PEEUU–FA sample induced lower platelet adhesion compared to the PEEUU sample. Reductions in hemolysis and fibrinogen adsorption were detected on the PEEUU–FA sample. Cell studies showed that PEEUU–FA supported the adhesion, expansion and proliferation of endothelial cells. The cells maintained an endothelial cell phenotype through the expression of the endothelial cell marker CD31. The results revealed that the new PEEUU modified with FA can be considered as a promising candidate for vascular applications with enhanced blood compatibility and vascular cell-compatibility. (paper)