Evaluation of collagen-elastin hybrid tissue engineered vascular constructs

Collagen-based tissue engineered replacements for small diameter blood vessels have been investigated for many years but typically lack the elasticity and tensile strength necessary for implantation. In this study, we have incorporated elastin with an organized structural architecture into tubular cell-seeded collagen constructs using two different reconstituted collagen sources. We evaluated the mechanical, chemical, and biological properties of these collagen-only and collagen-elastin hybrid grafts. Gel compaction quantification and live/dead staining revealed that cells in all matrix combinations were viable and able to rapidly compact their surrounding matrix. Compared to controls, uniaxial tensile testing revealed an increase in ultimate tensile strength and linear modulus for elastin hybrid constructs and for constructs formed with bovine dermal type I collagen. Histological assessment showed the unique composite structure of the elastin hybrid construct as well as the cell and extracellular matrix organization in all constructs studied. A discussion of these findings and their importance to vascular tissue engineering is discussed.