An integrated strategy for designing and fabricating triple-layer vascular graft with oriented microgrooves to promote endothelialization.

Compared with native blood vessels and existing vascular grafts, design and manufacture of vascular grafts with a three-dimensional topological structure is a key to induce cells and tissue growth, which remains an essential issue in both tissue engineering and regenerative medicine. This study sought to develop a novel triple-layer vascular graft (TLVG) with oriented microgrooves to investigate the mechanical property and endothelialization. The TLVGs were composed of electrospun Poly-ε-caprolactone (PCL)/thermoplastic polyurethane (TPU) as the inner layer, albumen/sodium alginate (SA) hydrogel as the middle layer, and electrospun PCL/TPU as the outer layer. In detail, a cylindrical sacrificial template was designed and printed using polyvinyl alcohol (PVA), served as the electrospinning receiving platform to form the oriented microgrooves in the inner layer of TLVGs. The highly elastic albumen/SA hydrogel and PCL/TPU nanofibers were able to simulate the elastin in blood vessels. In addition, the introduction of the albumen/SA hydrogel layer not only solves the leakage problem of a porous vascular graft but also improves the wettability of the scaffolds. The physicochemical properties and biological characteristics of TLVGs were evaluated by tensile testing, Surface wettability test, Fourier transform-infrared spectroscopy (FTIR) measurement, Live-Dead cell staining assay, and CCK-8 assay. Especially, the oriented microgrooves on the inner surface of the TLVGs can promote human umbilical vein endothelial cells (HUVECs) directed growth and migration in favor of endothelialization. All results showed that the fabricated TLVGs with excellent physicochemical properties and biocompatibility has great potential in clinic application.