Construction of vascular graft with circumferentially oriented microchannels for improving artery regeneration.

Design and fabrication of scaffolds with three-dimensional (3D) topological cues inducing regeneration of the neo-tissue comparable to native one remains a major challenge in both scientific and clinical fields. Here, we developed a well-designed vascular graft with 3D highly interconnected and circumferentially oriented microchannels by using the sacrificial sugar microfiber leaching method. The microchannels structure was capable of promoting the migration, oriented arrangement, elongation, and the contractile phenotype expression of vascular smooth muscle cells (VSMCs) in vitro. After implantation into the rat aorta defect model, the microchannels in vascular grafts simultaneously improved the infiltration and aligned arrangement of VSMCs and the oriented deposition of extracellular matrix (ECM), as well as the recruitment and polarization of macrophages. These positive results also provided protection and support for ECs growth, and ultimately accelerated the endothelialization. Our research provides a new strategy for the fabrication of grafts with the capability of inducing arterial regeneration, which could be further extended to apply in preparing other kinds of oriented scaffolds aiming to guide oriented tissue in situ regeneration.