Dual-Functional Nanofiber Vascular Graft Combining Early Cannulation and Long-Term Thrombosis Resistance for Hemodialysis Access

The global hemodialysis population is growing by 5–6% annually and is projected to reach approximately 5.4 million by 2030. Hemodialysis requires a vascular access "shunt" created by anastomosing an artery and vein, but patients with poor native vessels require an artificial graft. Such grafts occlude more readily than native vessels, necessitating repeated catheter interventions and additional medical costs. Among grafts in clinical use, expanded polytetrafluoroethylene (ePTFE) offers long-term patency while polyurethane (PU) allows early cannulation; however, no graft satisfies both occlusion resistance and early postoperative use. Here, we developed a graft combining these properties by integrating poly(2-methoxyethyl acrylate) (PMEA), which suppresses thrombus formation via an intermediate water layer, with Tecoflex, a PU enabling early cannulation.

PU and PMEA were each dissolved in DMF:chloroform (3:1) as 20 wt% solutions and blended at PU:PMEA ratios of 7:3, 8:2, and 9:1. Each was electrospun into nanofibers and formed into tubular grafts. To preserve strength, PMEA-containing grafts were given a bilayer structure with an outer PU-only layer. Grafts were characterized by SEM, gas chromatography for PMEA content, albumin and fibrinogen adsorption, human platelet adhesion and activation, water contact angle, ATR-IR analysis of interfacial water, tensile strength, and cytotoxicity, with PU-only grafts as controls. In vivo patency was evaluated by rat abdominal aorta replacement with HE staining.

Increasing PMEA content raised the intermediate water content and suppressed protein adsorption and platelet adhesion/activation. PMEA-containing grafts maintained high patency in vivo, with histologically reduced intimal hyperplasia and no excessive hyperplasia near the anastomosis. These findings provide a foundational design strategy for a next-generation vascular access graft that reconciles early cannulation with thrombosis resistance