Composite Tissue-Engineered Small-Diameter Vascular Grafts Based on Polycaprolactone and Polyurethane with Growth Factors and Atrombogenic Drug Coatings: Surface Ultrastructure, Physical and Mechanical Properties.

There is a growing need for synthetic small-diameter vascular grafts (<6 mm) for bypass surgery since the majority of currently developed products have demonstrated unacceptable high frequency of thrombosis in preclinical studies. The proprietary composite vascular graft based on a nonwoven polymer with anti-thrombogenic and anti-aneurysm effect and functional activity is aimed at stimulating the formation of vascular neotissue at the implantation site. Materials and Methods: PCL/PU vascular grafts with growth factor mix (GFmix) were manufactured using the electrospinning method. The hydrogel coating containing iloprost (Ilo) and heparin (Hep) was formed by complexation with polyvinylpyrrolidone. The controls were multilayer vascular grafts of similar composition and nonwoven matrices based on 12% PCL and 12% PU. The surface structure was analyzed with the S-3400N scanning electron microscope (Hitachi, Japan). The physical properties of the surface were determined by the wetting angle method. The mechanical properties were evaluated on a Z series universal testing machine (Zwick/ Roell, Germany). Statistical processing of the data was performed using the GraphPad Prism 8 software. Results: Our new manufacturing technique for the composite PU/PCL/GFmix/ Conclusion: The composite functionalized vascular PU/PCL/GFmix/