Multilayered Hollow Tubes as Blood Vessel Substitutes

The available therapies for cardiovascular pathologies often require the replacement of diseased vascular grafts. However, the current blood vessel substitutes are unsuitable for small-diameter blood vessel replacements. Herein, we propose the creation of multilayered hollow tubes as blood vessel substitutes. Hollow tubes were obtained by building-up multilayers of marine-derived polysaccharides (i.e., chitosan and alginate) on sacrificial tubular templates using layer-by-layer technology and template leaching. A cross-linking degree of approximate to 59% was achieved using genipin, which is reflected in an increase of the mechanical properties and a decrease of the water uptake. To further improve the cell adhesive properties of the multilayers, fibronectin (FN) was immobilized on the surface of the hollow tubes. The in vitro biological performance of human umbilical vein endothelial cells (HUVECs) and human aortic smooth muscle cells (HASMCs) was assessed. In addition, to perform the culture of HUVECs on the inner side and the HASMCs on the outer side of the tubes, an in-house developed apparatus was created that allowed us to feed cells with their respective culture medium. The developed hollow tubes were shown to be a suitable structure to promote cell adhesion, spreading, and proliferation. It is our belief that the creation of these functional structures will open a new research field in order to develop innovative multilayered tubular structures for cardiovascular TE applications.