In vitro assessment of endothelial cell adhesion mechanism on vascular patches

Endothelial cell (EC) seeding of small caliber vascular grafts prior to their implantation has proved to significantly improve long-term patency in humans. We have previously demonstrated that a monolayer of EC could be obtained on type I collagen-coated knitted ultrathin polyster grafts (InterVascular, La Ciotat, France). Thus, the aim of the present work was to understand the nature of cell adhesion mechanisms involved in the cell /biomaterial interface, using HemaCarotid (InterVascular) patches made of type I collagen-coated knitted ultrathin polyster (type I collagen is used to coat patches to attain low permeability). By means of quantitative attachment tests, adhesion blocking assays, RT-PCR for the expression of beta1 integrin mRNA, indirect immunofluorescence with antivinculin antibody, we were able to show that EC are able to adhere to such surfaces by the means (non-unique) of cell surface receptors of the beta1 integrin group. However, the latter are probably downregulated at the cell/biomaterial interface.