Fibrin Coating Contributes to the Retention of the Endothelial Layer in Pulsating Flow

Abstract

The presence of a modifying coating based on extracellular matrix proteins on the inner surface of vascular prostheses is known to enhance endothelial cell adhesion and prevent detachment under pulsating flow conditions. This coating effectively reduces the risk of thrombosis and plays a critical role in determining implantation outcomes. Although proteins like collagen, fibrin, and fibrinogen are commonly used as coatings to improve cell adhesion, their relative effectiveness remains uncertain. Objective: This study aims to identify the optimal coating, based on extracellular matrix proteins, that preserves prosthesis functionality and maintains endothelial layer integrity under pulsating flow conditions. Methods: Scaffolds and vascular prostheses were fabricated using poly(3-hydroxybutyrate-co-3-hydroxyvalerate) and poly(ε-caprolactonone) through an electrospinning process. These structures were then modified with collagen I, fibronectin, or fibrin. Endothelial colony-forming cells (ECFCs) were seeded onto the protein-modified electrospun samples and cultured under both static and dynamic conditions. After a 3-day incubation period under static conditions, cell viability, metabolic and proliferative activity, as well as adhesive properties, were evaluated. Adhesive properties were assessed by analyzing the area occupied by the focal adhesion protein paxillin. Cell retention was determined by comparing cell density on the inner surface of 4 mm diameter vascular prostheses after a 7-day incubation period, both under pulsating flow conditions and static conditions. Results: Cell metabolic activity, viability, number, proliferation, and the area occupied by the focal adhesion protein paxillin were found to be significantly higher in samples coated with fibrin compared to those coated with collagen I and fibrinogen. The cell density (cells/cm2) of ECFCs on the inner surface of fibrin-coated prostheses showed no significant difference between dynamic and static conditions. In contrast, collagen and fibronectin coatings resulted in approximately half the cell density under pulsating flow conditions compared to static conditions. Conclusion: The fibrin coating demonstrated superior biological activity, adhesive properties, and preservation of the endothelial layer under both static and pulsating flow conditions, as compared to collagen I and fibronectin coatings. Consequently, the utilization of fibrin coating emerges as a promising option for modifying the inner surface of vascular prostheses.