Functionally Segmented Small-Diameter Vascular Grafts with Excellent Mechanical Matchability Prepared by Emulsion Spinning Method

Long-term patency remains the main challenge for small-diameter vascular grafts in clinical applications. In addition to anticoagulation and endothelialization, antiproliferative treatment of the autologous vessels at the suture site and mechanical compatibility are also important influences on long-term patency rates. In order to address these issues simultaneously, this study constructed a functionally segmented small-diameter vascular graft with anticoagulant and endothelialization functions in the whole-graft and antiproliferation functions at both ends by emulsion electrospinning. The functionally segmented vascular grafts were composed of thermoplastic polyurethane (TPU) and Type I collagen (Col), with heparin (Hep)/anti-CD133 antibody in the whole segment and rapamycin (RAPA) loaded at both ends. In addition，through component modulation, we prepared blood vessels possessing excellent mechanical matching with human autologous blood vessels, which is highly conducive to enhance the stability of blood vessels and promote endothelialization growth. Moreover, compared with the TPU group, the thermoplastic polyurethane/collagen/heparin/anti-CD133 antibody/rapamycin (TCHCR) group showed better biocompatibility and hemocompatibility. In vivo implantation experiments in the New Zealand Great White Rabbit have shown that the TCHCR group exhibited good anticoagulant, endothelialization and antiproliferative effects. Therefore，the functionally segmented vascular grafts we prepared may succeed in solving the problem of vascular long-term patency rates.