Preliminary application of a cell-free mono-layered vascular scaffold in a rabbit model

Abstract

Of the qualities small caliber artificial vascular scaffolds must possess for application in modified Blalock-Taussig (B-T) surgery, effective anticoagulation and mechanical maintenance take priority over structural bionics. Currently, only the IMPRA® ePTFE vascular graft is available. Here, we designed a mono-layered vascular scaffold by loading heparin (Hep), made up of poly(l-lactide-co-caprolactone) (PLCL) and silk fibroin (SF), through a conjugate electrospinning technique. Three kinds of Hep@SF/PLCL nanofiber membranes containing different SF and heparin contents were produced by adjusting the spinning speed of a Hep@SF mixed solution. Compared to the other two nanofiber membranes, the 1.0Hep@SF/PLCL nanofiber membrane contained the most SF, resulting in suitable radial tensile property, optimal hydrophilicity, cytocompatibility and antithrombotic activity. Therefore, we then prepared a mono-layered artificial vascular scaffold using this design. Finally, orthotopic rabbit carotid artery transplantation was performed to evaluate remodeling effect in vivo. Three months after surgery, the 1.0Hep@SF/PLCL vascular scaffold exhibited satisfactory remodeling in vivo, resulting in a regenerated smooth muscle layer covered by a continuous endothelium.