A vascular graft with hydrogen-bonded network structure for leak-free puncture resistance, spatiotemporal anticoagulation, and rapid endothelialization via fucoidan-heparin functionalization

Small-diameter vascular grafts for vascular access applications face three major challenges: thrombosis, difficulty in endothelialization, and post-puncture blood leakage. Existing vascular grafts struggle to meet these three critical requirements simultaneously. To address these challenges, we designed and fabricated a dual-network vascular graft composed of thermoplastic polyurethane (TPU)/polyvinyl alcohol (PVA) &fucoidan-heparin (TPFH). Using a dual-nozzle electrospinning technique combined with covalent modification, we constructed a functionalized graft with strong hydrogen bonding and microphase separation characteristics, which exhibited self-healing capability after puncture and effectively prevents blood leakage. After undergoing 24 puncture cycles (equivalent to 18 months of clinical use), the mechanical properties of the graft remained superior to those of human coronary arteries, meeting the long-term usage requirements for arteriovenous grafts. In terms of anticoagulant function, fucoidan acted as a fast-response molecule that migrated to the damaged site after puncture to achieve immediate anticoagulation, while the covalently grafted heparin provides stable long-term antithrombotic protection for the whole lumen. Furthermore, the TPFH dual-network structure not only mimics the extracellular matrix but also significantly improves material hydrophilicity, effectively promoting endothelial cell adhesion and proliferation. Subcutaneous implantation in rat models confirmed its good biocompatibility. This study provides a feasible strategy for developing novel vascular grafts with integrated leakage resistance, spatiotemporal anticoagulation, and pro-endothelialization functions, showing promising potential for hemodialysis vascular access.