A Rapid In Vitro Endothelialization Approach for Small‐Diameter Vascular Grafts via Covalent Reaction

Abstract Small‐diameter vascular grafts are prone to thrombosis and stenosis mainly due to inadequate endothelialization. The current in vitro endothelial cells (ECs) seeding methods are time‐consuming and insufficient to resist blood flow erosion, which limited the application of pre‐endothelialized grafts. Herein, human induced pluripotent stem cell‐derived ECs (hiPSC‐ECs) are modified with azide group via metabolic glycoengineering. Then, these cells can achieve complete endothelial coverage on the lumen surface of Dibenzocyclooctyne (DBCO)‐functionalized polycaprolactone (PCL) grafts via click reaction at 2 h, which is currently the fastest method. Transcriptomic analysis reveals upregulated cytoskeletal/ junctional genes and suppressed inflammatory pathways, suggesting enhanced endothelial barrier function. In the mouse carotid artery replacement model, the click‐endothelialized exhibits ≈64% cell retention at 7 days and achieve a 100% patency at 30 days, which is both superior to the traditional seeding group (retention rate ≈ 2%; patency rate = 33.3%). The implanted hiPSC‐ECs accelerate host endothelial regeneration and attenuate inflammation response of grafts. At 90 days, the regenerated ECs and smooth muscle cells exhibited a tissue structure similar to that of a natural artery. The click reaction‐mediated seeding strategy provides a rapid and stable pre‐endothelialization approach, which may be promote the application of pre‐endothelialization grafts, especially for emergency vascular surgery.