Design and evaluation of scaffolds for arterial grafts using extracellular matrix based materials

Abstract

For small diameter (<6 mm) blood vessel replacements, lack of collaterals and vascular disease preclude homografts; while synthetic analogs, ePTFE, expanded polytetrafluoroethylene, and PET, polyethyleneterephathalate, are prone to acute thrombosis and restenosis. It is postulated that the hierarchical assembly of cell populated matrices fabricated from protein analogs provides a new design strategy for generating a structurally viable tissue engineered vascular graft. To this end, synthetic elastin and collagen fiber analogs offer a novel strategy for creating tissue engineered vascular grafts with mechanical and biological properties that match or exceed those of native vessels. This work details techniques developed for the fabrication of prosthetic vascular grafts from a series of extracellular matrix analogs composed of nanofibrous collagen matrices and elastin-mimetic proteins, with and without cells, and subsequent evaluation of their biocompatibility and mechanical properties. The work details the fabrication and mechanical analysis of vascular grafts made from aforementioned protein analogs. Subesequent studies detail seeding and proliferation of rodent mesenchymal stem cells on protein-based composites to recapitulate the media of native vasculature. Finally detailing in vivo biocompatibility and stability of tissue engineered vascular grafts.