Grant: Operating Grant

Heart disease is a condition where the arteries nourishing the heart become too narrow. A common procedure to treat heart disease is to implant stents to reopen the blood vessels. Over 50 000 coronary artery interventions are performed in Canada each year. To reduce the risks of complications such as sudden heart failure years later, a normal cell lining should be re-established on the stent surface. The endothelial cells that cover our healthy blood vessels secrete molecules that inhibit blood clotting and vessel narrowing. To restore this cell lining, the stents can be coated with antibodies that capture endothelial progenitor cells from the blood stream. These cells can generate large numbers of endothelial cells in vitro. Studies have shown that stents that capture the circulating progenitor cells become covered by endothelial cells. However, this did not improve the performance of the stents. We hypothesize that this is due to the lack of a natural microenvironment to help cell growth and maturation. More mature endothelial cells should produce higher amounts of the molecules that inhibit blood vessel obstruction. We therefore propose to engineer stents that mimic the normal endothelial cell environment. To do so, we will coat the stents with combinations of molecules involved in endothelial cell adhesion, growth and maturation. We will also use stents that slowly dissolve over time. These stents would provide the transient support needed to reopen the vessel and recruit cells with regenerative potential. The use of biodegradable materials will avoid leaving a foreign body behind once the stents have served their purpose. These engineered materials could help restore a normal vasculature at the implant site. The stents developed during this project could help patients suffering from heart disease live without the constant fear of a recurrent heart failure or other complications.