Developing small-diameter vascular grafts with human amniotic membrane: long-term evaluation of transplantation outcomes in a small animal model.

While current clinical utilization of large vascular grafts for vascular transplantation is encouraging, tissue engineering of small grafts still faces numerous challenges. This study aims to investigate the feasibility of constructing a small vascular graft from the decellularized amniotic membranes (DAMs). DAMs were rolled around a catheter and each of the resulting grafts was crosslinked with a) 0.1% glutaraldehyde; b) EDC (20mM)-NHS (10mM); c) 0.5% genipin; and d) no-crosslinking, respectively. Our results demonstrated the feasibility of using a rolling technique followed by lyophilization to transform DAM into a vessel-like structure. The genipin-crosslinked DAM graft showed an improved integrated structure, prolonged stability, proper mechanical property, and superior biocompatibility. After transplantation in rat abdominal aorta, the genipin-crosslinked DAM graft remained patent up to 16-month, with both endothelial and smooth muscle cell regeneration, which suggests that the genipin-crosslinked DAM graft has great potential to be implemented as a small tissue engineered graft for future vascular transplantation.