Small-Diameter Artificial Arteries Engineered In Vitro

Abstract

Abstract-Although the need for a functional arterial replacement is clear, the lower blood flow velocities of small-diameter arteries like the coronary artery have led to the failure of synthetic materials that are successful for large-diameter grafts. Although autologous vessels remain the standard for small diameter grafts, many patients do not have a vessel suitable for use because of vascular disease, amputation, or previous harvest. As a result, tissue engineering has emerged as a promising approach to address the shortcomings of current therapies. Investigators have explored the use of arterial tissue cells or differentiated stem cells combined with various types of natural and synthetic scaffolds to make tubular constructs and subject them to chemical and/or mechanical stimulation in an attempt to develop a functional small-diameter arterial replacement graft with varying degrees of success. Here, we review the progress in all these major facets of the field. Key Words: tissue engineering Ⅲ artery Ⅲ collagen Ⅲ elastin Ⅲ vascular graft I n 2002, more than 500 000 surgical procedures were performed involving replacement of small-caliber blood vessels. 1 Despite a clear clinical need for a functional arterial graft, success has been limited to arterial replacements of large-caliber vessels such as the thoracic and abdominal aorta, arch vessels, iliac, and common femoral arteries; however, small-caliber (Ͻ6 mm) arterial substitutes, which account for a majority of the demand, have generally proved inadequate largely because of acute thrombogenicity of the graft, anastomotic intimal hyperplasia, aneurysm formation, infection, and progression of atherosclerotic disease. 2 The lower blood flow velocities of smaller vessels pose a different set of design criteria and introduce a host of new problems not encountered in large-caliber arterial substitutes where Dacron and expanded polytetrafluorethylene grafts have succeeded.Although autologous vessels, such as the saphenous vein, remain the standard for small diameter grafts, many patients do not have a vessel suitable for use because of vascular disease, amputation, or previous harvest. Moreover, this method requires a second surgical procedure to obtain the vessel. Tissue engineering has emerged as a promising approach to address the shortcomings of current options. Investigators have explored the use of arterial tissue cells combined with various types of natural and synthetic scaffolds to make tubular constructs and subject them to chemical and/or mechanical stimulation in an attempt to develop a functional small-diameter arterial replacement graft with varying degrees of success. There have been several reviews of vascular tissue engineering studies in recent years. [3][4][5][6] Here, we review the progress in Many design criteria have been proposed for the development of a functional small-diameter arterial replacement graft. 2,5,6,9 -13 It must be biocompatible, ie, nonthrombogenic, nonimmunogenic, and resistant to infection, all of which are associated wi...

Biomimetic materials for tissue engineering

“…Engineering these tissues has been a continuous effort in the tissue engineering community [18][19][20][21][22]. To achieve the needed elastomeric properties, various elastomeric materials have been evaluated as the scaffolds to engineer these tissues.…”

“…To achieve the needed elastomeric properties, various elastomeric materials have been evaluated as the scaffolds to engineer these tissues. In addition to elastic materials derived from the natural ECM [22], poly(ε-cprolactone) (PCL) and polyurethanes (PU) are some of the typical synthetic polymers. PCL is a semicrystalline polymer, has a very low glass-transition temperature (around −62°C), and thus is highly elastic at room or body temperature.…”

Tailoring Mechanical Properties of Collagen-Based Scaffolds for Vascular Tissue Engineering: The Effects of pH, Temperature and Ionic Strength on Gelation

“…When small caliber (ø < 6 mm) blood vessels have to be replaced and autologous substitutes are unavailable, synthetic grafts do not represent a long-term alternative and other options have to be considered [2][3][4][5]. Scaffold-based vascular tissue engineering (VTE) proposes to combine cells and scaffolding systems in order to obtain vascular constructs [4].…”

ECM-based triple layered scaffolds for vascular tissue engineering

“…Although successful with large diameter (>6 mm) high-flow vessels, autografts, allografts or synthetic prosthetic grafts can not meet clinical demand, especially in low-flow small-diameter vascular grafts (SDVGs) which are often connected with thrombosis, aneurysm formation, calcification, and severe inflammatory reactions (3). Even though autologous grafts have excellent long-term properties, their scarcity is a disadvantage (4). Vascular tissue engineering, however, is a multidisciplinary approach which could be applied to create completely biological and functional SDVGs whenever required.…”