The regeneration of macro-porous electrospun poly(ɛ-caprolactone) vascular graft during long-term in situ implantation.

Long-term evaluation of vascular grafts is an essential step to facilitate clinical translation. In this study, we investigate the long-term performance of a macro-porous poly(ɛ-caprolactone) (PCL) electrospun vascular graft using the rat abdominal artery replacement model. Long-term patency, endothelialization, and smooth muscle cell regeneration were evaluated, as well as calcification and degradation. The data showed that all the grafts remained open and unobstructed. There was no evidence of aneurysm, stenosis, or calcification one year after implantation. Importantly, neo-vessel was regenerated on the luminal surface of the graft, and was composed of a complete endothelial layer and several layers of smooth muscle cells. The neo-vessel showed vascular physiological function, although not as good as that in native blood vessels, likely due to the remaining scaffold fibers. These data indicated that the PCL macro-porous electrospun vascular graft has potential to be an artery substitute for long-term implantation. Also, this work indicates that continued efforts are needed to develop advanced vascular grafts that exhibit the appropriate balance between the regeneration of the neo-vessel and the complete degradation of the graft materials. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 1618-1627, 2018.