Endothelial Outgrowth Cells: Function and Performance in Vascular Grafts

Abstract

The clinical need for vascular grafts continues to grow. Tissue engineering strategies have been employed to develop vascular grafts for patients lacking sufficient autologous vessels for grafting. Restoring a functional endothelium on the graft lumen has been shown to greatly improve the long-term patency of small-diameter grafts. However, obtaining an autologous source of endothelial cells for in vitro endothelialization is invasive and often not a viable option. Endothelial outgrowth cells (EOCs), derived from circulating progenitor cells in peripheral blood, provide an alternative cell source for engineering an autologous endothelium. This review aims at highlighting the role of EOCs in the regulation of processes that are central to vascular graft performance. To characterize EOC performance in vascular grafts, this review identifies the characteristics of EOCs, defines functional performance criteria for EOCs in vascular grafts, and summarizes the existing work in developing vascular grafts with EOCs.

Harnessing developmental processes for vascular engineering and regeneration

“…These primary ECs have been widely used in vascular engineering for many years because they already possess the functional attributes of ECs and thus require little manipulation prior to transplantation. In the past decade, EPCs, such as endothelial colony-forming cells (ECFCs) (Critser and Yoder, 2010) and human outgrowth ECs (Lin et al, 2000;Glynn and Hinds, 2013), have also been investigated for vascular tissue engineering. These cells circulate in the bloodstream and can be differentiated into ECs, contributing to vasculogenesis and angiogenesis (Asahara et al, 1997;Richardson and Yoder, 2011).…”

In Vitro Endothelialization of Biodegradable Vascular Grafts Via Endothelial Progenitor Cell Seeding and Maturation in a Tubular Perfusion System Bioreactor

“…Thus, these cells may prove to be promising candidates for the seeding of vascular grafts before implantation. 15 Biomechanical stimuli serve as integral components to the development of a mature endothelium. Mechanical forces applied by blood flow can affect vascular remodeling, homeostasis, and disease.…”

Blood Outgrowth Endothelial Cells Alter Remodeling of Completely Biological Engineered Grafts Implanted into the Sheep Femoral Artery

“…A recent study performed in the porcine model demonstrates clear benefit of pre-seeding endothelial cells (EC) [1]: patency was substantially improved and neo-intima formation was attenuated with both autologous vessel EC and circulating endothelial progenitor cells (EPC). Use of autologous blood outgrowth endothelial cells (BOEC, also referred to as late-outgrowth EPC), presents a uniquely advantageous strategy for fabricating TEVG with anti-thrombogenic functionality [6, 7]. These cells can be isolated from a small amount of blood obtained via routine venipuncture and expanded extensively (to 10 19 cells) [6], including some patients with coronary artery disease [8].…”