Mon, Jan 31, 2011 @ 12:30 PM - 01:50 PM
Alfred E. Mann Department of Biomedical Engineering
Conferences, Lectures, & Seminars
Speaker: Dr. George Truskey, Duke University
Talk Title: Engineering Endothelial Progenitor Cells for Vascular Repair
Series: Invited Chair Series
Abstract: Endothelial progenitor cells can be obtained from cord blood, adult blood or bone marrow and serve as a potential source of vascular endothelium for a variety of therapeutic applications. Our own work has focused upon using late outgrowth endothelial progenitor cells for a variety of applications including seeding vascular devices, preparing, tissue engineered blood vessels and repair of endothelial injury. The focus of this talk is upon the use of human endothelial cells derived from late outgrowth cord bold (hCB-ECs) to accelerate vein graft re-endothelialization, and reduce vein graft atherosclerosis.
As a principal cause of vein graft failure, endothelial injury complicates ~500,000 vein graft procedures performed annually in the US to treat atherosclerosis. Over-distension of the vein graft by arterial pressure leads to endothelial injury, which exposes the extracellular matrix to circulating blood and promotes vein graft thrombosis. Neointimal hyperplasia subsequently predisposes vein grafts to accelerated atherosclerosis, and late vein graft failure. The hCB-ECs function similarly to vascular endothelium. The hCB-ECs demonstrate smaller size, superior adhesive properties and higher 51 integrin expression levels compared with EC adhesion to SMC/extracellular matrix is significantly greater under flow conditions with hCB-ECs than with ECs derived from adult human peripheral blood EPCs. When administered intravenously, hCB-ECs enhanced vein graft re-endothelialization, and prevented thrombosis in carotid interposition vein grafts implanted in SCID mice. To better understand the adhesion process, we examined adhesion of hCB-ECs as a function of shear stress in vitro. The number of adherent cells varied with shear stress, with the maximum number of adherent cells and the shear stress at maximum adhesion depending upon fluid viscosity. A dimensional analysis indicated that adhesion was a function of the net force on the cells, the ratio of cell diffusion to sliding speed and molecular diffusivity. This work suggests that delivery conditions can be developed to maximize adhesion of EPCs for repair of damaged arteries.
Host: Department of Biomedical Engineering, USC
Location: Olin Hall of Engineering (OHE) - 122
Audiences: Everyone Is Invited
Contact: Mischalgrace Diasanta