Cross‐Linking of a Triple‐Layered Polymeric‐Collagen Vascular Graft by Carbodiimide for Enhanced Mechanical Properties and Biocompatibility

Abstract

Based on the characteristics of natural blood vessels, polylactic acid (PLA), polyurethane (PU), and collagen (COL) were utilized as raw materials to fabricate a small‐diameter three‐layered artificial vascular graft to mimic their structural and functional properties via sequential electrospinning technology. The inner layer with smooth surface was comprised of PLA, PU, and COL, the middle layer offering mechanical strength and elasticity was comprised of PU and COL, and the outer layer ensuring structural support and integration with surrounding tissues was composed of PLA and COL. Enhancement of performance was achieved through EDC/NHS crosslinking treatment. Results indicated improved mechanical properties (longitudinal increase of 43.35%, transverse increase of 29.36%) and enhanced hydrophilicity (from 61.6° to 54.7°) after EDC/NHS crosslinking treatment. Furthermore, L929 cell survival rates exceeded 80% after 1 day's cultivation in leaching solutions of the vascular grafts, and stable growth of the cells was observed after 7 days' cultivation, suggesting low toxicity and good biocompatibility. All samples demonstrated hemolysis rates were below 5%, indicating that the rupture of red blood cells was effectively limited upon contact with the vascular grafts. Overall, enhanced tensile properties, preliminary in vitro cytocompatibility, and low hemolytic activity were exhibited by the crosslinked PLA‐COL@PU‐COL@PLA‐PU‐COL scaffolds, which supports further vascular‐specific biological evaluations.