Vascular smooth muscle cells on hyaluronic acid: culture and mechanical characterization of an engineered vascular construct.

Esterified hyaluronic acid (HYAFF) is routinely used for clinical tissue-engineering applications such as skin and cartilage. The material is degraded by neotissue formation and degradation products are highly biocompatible. In the present article we investigate the possibility to culture vascular smooth muscle cells on this biodegradable material for the generation of tubular constructs to be used for vascular tissue engineering. We have evaluated cell attachment and growth, and the possibility to obtain a three-dimensional tubular shape culture from flat HYAFF sheets. We also evaluated the mechanical properties of the cell constructs, using a specific testing protocol, and compared them with the properties of segments of porcine coronary artery. Morphology and viability tests demonstrated that vascular cells, either from porcine or human origin, adhere and grow on nonwoven meshes of HYAFF, and that precoating of the material with fibronectin or collagen had a modest effect on cell growth and extracellular matrix production. Cell growth reached a maximum 7 days after seeding. Simple wrapping of flat sheets of nonwoven meshes containing vascular cells around a cylindrical mandrel, and culture under static conditions for 14 days, yielded tubular constructs suitable for mechanical tests. Despite cell colonization, constructs showed lower mechanical resistance as compared with porcine coronary arteries. The material used and the technique developed result in highly cellularized tubular constructs. Whether the mechanical properties may be improved by dynamic culture conditions is worthy of investigation.