Rapid Endothelialization of Off-the-Shelf Small Diameter Silk Vascular Grafts

Highlights • Bombyx mori silk was electrospun to engineer mechanically robust vascular grafts that support endothelial cell attachment and monolayer formation while resisting blood adhesion and fibrin assembly in vitro. •Silk grafts were evaluated in a rat aortic interposition grafting model at 3, 6, 12, and 24 weeks. Graft survival for silk grafts (95%) was superior to control ePTFE (73%) at 24 weeks. •Comprehensive histologic analysis of the grafts demonstrated near complete endothelialization by 6 weeks, which occurred concomitantly with neointima regression, characterized by a loss in cellularity, a phenotypic switch in SMC and an increased ECM expression. •Silk grafts appear to undergo positive remodeling over time, with temporal reductions in apoptotic and inflammatory cells, adventitial granulation tissue, and the deposition of new ECM proteins.