Generating vascular conduits: from tissue engineering to three-dimensional bioprinting

Abstract

Vascular disease – including coronary artery disease, carotid artery disease, and peripheral vascular disease – is a leading cause of morbidity and mortality worldwide. The standard of care for restoring patency or bypassing occluded vessels involves using autologous grafts, typically the saphenous veins or internal mammary arteries. Yet, many patients who need life- or limb-saving procedures have poor outcomes, and a third of patients who need vascular intervention have multivessel disease and therefore lack appropriate vasculature to harvest autologous grafts from. Given the steady increase in the prevalence of vascular disease, there is great need for grafts with the biological and mechanical properties of native vessels that can be used as vascular conduits. In this review, we present an overview of methods that have been employed to generate suitable vascular conduits, focusing on the advances in tissue engineering methods and current three-dimensional (3D) bioprinting methods. Tissue-engineered vascular grafts have been fabricated using a variety of approaches such as using preexisting scaffolds and acellular organic compounds. We also give an extensive overview of the novel use of 3D bioprinting as means of generating new vascular conduits. Different strategies have been employed in bioprinting, and the use of cell-based inks to create de novo structures offers a promising solution to bridge the gap of paucity of optimal donor grafts. Lastly, we provide a glimpse of our work to create scaffold-free, bioreactor-free, 3D bioprinted vessels from a combination of rat vascular smooth muscle cells and fibroblasts that remain patent and retain the tensile and mechanical strength of native vessels.

Acellular Small-Diameter Tissue-Engineered Vascular Grafts

“…Three-dimensional printing technology has been applied in many different fields. Bio-printing is already commonly used in tissue engineering and is also a method for fabricating TEVG [25]. As introduced previously, support materials mixed with seed cells are the starting materials for fabricating printed TEVGs.…”

Development of drug loaded cardiovascular prosthesis for thrombosis prevention using 3D printing

“…Revascularization techniques include angioplasty, placement of a stent, or surgical bypass grafting [ 6 ]. For the latter technique, autologous vessels remain the best clinical option, but the process of harvesting vessels is invasive, and they are often unsuitable [ [7] , [8] , [9] ]. Therefore, synthetic vascular grafts made from biocompatible materials are still needed [ 1 , 6 ].…”

Endothelialization of an ePTFE vessel prosthesis modified with an antithrombogenic fibrin/heparin coating enriched with bound growth factors

“…Currently, the best conduits for vascular graing are autologous arteries or veins, typically the saphenous veins, internal mammary arteries, or radial arteries. 1,2 Nevertheless, they have several drawbacks: limited availability; donor site morbidity and patient burden due to the requirement for additional surgery. As a result, synthetic polymer VGs made from expanded polytetrauoroethylene (ePTFE), polyethylene terephthalate (PET, Dacron), and polyurethane (PU) are routinely used in current clinical practice as an alternative to autologous vessels.…”