Objective: To design a novel small-caliber vascular graft using a decellularized allogeneic vascular scaffold pre-loaded with bFGF.
Methods: The decellularized canine common carotid were obtained by a detergent-enzymatic procedure, then the scaffolds were covalently linked with heparin and pre-loaded with bFGF, the amount of binding bFGF and releasing curve were assayed by ELISA. Canine BMSCs expanded in vitro were seed on the scaffolds to observe the effects of binding bFGF on proliferation. Both bFGF pre-loaded and non-pre-loaded decellularized grafts were implanted in canines as carotid artery interposition for 8 weeks, the patency was examined by digital subtraction angiography and histological method.
Results: Histology and electron microscopic examination of the decellularized scaffolds showed that cellular components were removed completely and that the extracellular matrix structure remained intact. The amount of binding bFGF positively related to the concentration of bFGF. There was a significant difference in the amount of binding bFGF between two different scaffolds throughout all bFGF concentrations (P < 0.05), and up to 100 ng/mL, the local and sustained release of bFGF from the heparin treated scaffolds were assayed up to 20 days. Additionally, MTT test showed the bFGF-preloaded scaffolds significantly enhanced the proliferation of seeded BMSCs in vitro compared with non-bFGF-preloaded scaffolds at 3 days after seeding and thereafter (P < 0.01). Furthermore, in vivo canine experiments revealed that all 8 bFGF-pre-loaded scaffolds remained patent after 8 weeks of implantation, and host cell lined the lumen and populated the wall. Only 1 non-bFGF-pre-loaded scaffold was patent, and the other 7 grafts were occluded because of thrombsus formation.
Conclusion: This study provides a new strategy to develop a small diameter vascular graft with excellent biocompatibility and high patency rate.