TISSUE-ENGINEERED VASCULAR GRAFT: ASSESSMENT OF MATERIAL QUALITY AND ACTIVITY OF ANTI-TROMBOGENIC COATING

Highlights The original method of forming a hydrogel anti-trombogenic drug coating on the inner surface of a small diameter vascular graft did not affect the baseline structural, physical and mechanical properties of the product. Loading iloprost and heparin into the coating significantly improved the hemocompatibility of the material with respect to inhibition of platelet aggregation. Aim . To evaluate structural, physical and mechanical characteristics of a drug-eluting tissue-engineered vascular graft and the functional activity of its coating. Methods. Vascular grafts based on polycaprolactone and polyurethane with growth factors were manufactured by emulsion electrospinning. The modified coating on the inner surface of the graft consisted of a hydrogel layer loaded with iloprost and heparin. The surface structure was studied by scanning electron microscopy, physical and mechanical characteristics were studied using a universal Zwick/Roell testing machine, surface properties were studied by contact angle measurements and wettability. The functional activity of the modified coating was assessed with the help of indicators of maximum platelet aggregation upon contact with the material. Results. The results showed that forming the coating did not change the architectonics of the polymer matrix surface. The structure of the graft was represented by randomly directed micro- and nanofibers with heterogeneous pores and without deformation of material; the surface of the graft retained hydrophilicity (θ = 68.6 ± 11.85). We confirmed the success of surface modification of vascular graft by observing extremely low values of the maximum platelet aggregation upon contact of platelet-rich plasma with the surface of the graft (8,5 (7,2; 12,2) %). Depending on the conditions of their incubation in saline solution, we have noted the prolongation of the drug-releasing activity. Conclusion. The formation of anti-thrombogenic coating on the surface of the PCL/PU/GFmix/ Ilo/Hep vascular graft did not negatively affect the structural characteristics or physical and mechanical properties, moreover, it significantly improved hemocompatibility in terms of inhibition of platelet aggregation.