Bioengineered Vascular Scaffolds: The State of the Art

Abstract

To date, there is increasing clinical need for vascular substitutes due to accidents, malformations, and ischemic diseases. Over the years, many approaches have been developed to solve this problem, starting from autologous native vessels to artificial vascular grafts; unfortunately, none of these have provided the perfect vascular substitute. All have been burdened by various complications, including infection, thrombogenicity, calcification, foreign body reaction, lack of growth potential, late stenosis and occlusion from intimal hyperplasia, and pseudoaneurysm formation. In the last few years, vascular tissue engineering has emerged as one of the most promising approaches for producing mechanically competent vascular substitutes. Nanotechnologies have contributed their part, allowing extraordinarily biostable and biocompatible materials to be developed. Specifically, the use of electrospinning to manufacture conduits able to guarantee a stable flow of biological fluids and guide the formation of a new vessel has revolutionized the concept of the vascular substitute. The electrospinning technique allows extracellular matrix (ECM) to be mimicked with high fidelity, reproducing its porosity and complexity, and providing an environment suitable for cell growth. In the future, a better knowledge of ECM and the manufacture of new materials will allow us to “create” functional biological vessels - the base required to develop organ substitutes and eventually solve the problem of organ failure.

Conjugation with RGD Peptides and Incorporation of Vascular Endothelial Growth Factor Are Equally Efficient for Biofunctionalization of Tissue-Engineered Vascular Grafts

“…Vascular tissue engineering is considered as a promising approach for producing biocompatible and mechanically competent small caliber vascular substitutes [9]. Many types of natural and synthetic biodegradable polymers have been investigated and used to prepare tubular grafts for in situ vascular tissue engineering [7].…”

Cell-microenvironment interactions and architectures in microvascular systems

“…Several literature reviews have largely focused on identifying critical aspects for successful development of vascularized models. Many of them were found to be mainly focused on the fundamental principles of engineering, microfabrication techniques (Auger et al, 2013) and microfluidic technologies (Inamdar and Borenstein, 2011, Wong et al, 2012), while other reviews highlighted the pivotal role of cell sources (Baldwin et al, 2014), scaffolds and pro-angiogenic factors (Bae et al, 2012, Kaully et al, 2009, Palumbo et al, 2014, Park and Gerecht, 2014) with low emphasis on microfabrication strategies. This review attempts to critically summarize and connect engineering principles and biological considerations as well as highlight how design of the system architecture and selection of the most suitable microfabrication technique are the first steps for analyzing biological phenomena occurring in a specific environment.…”

Human Peripheral Blood-Derived Endothelial Colony-Forming Cells Are Highly Similar to Mature Vascular Endothelial Cells yet Demonstrate a Transitional Transcriptomic Signature

“…or saphenous veins is often limited in patients with widespread atherosclerotic vascular disease or in those whose vessels are anatomically incompatible or have already been harvested for a previous procedure [2][3][4]. Allogeneic and xenogeneic blood vessels demonstrate only a limited efficiency due to the risk of transmissible disease, graft-versus-host disease, infection, and calcification [4,5] while prosthetic grafts fabricated from biostable synthetic polymers such as poly(ethylene terephthalate), expanded poly(tetrafluoroethylene), and polyurethanes show inferior patency rates in small-diameter applications due to poor endothelialization, low blood flow, and compliance mismatch, all resulting in intimal hyperplasia, thrombosis, or (pseudo)aneurysms [2][3][4][5]. In addition, both xenogeneic and biostable synthetic vascular conduits lack growth adaptation potential and therefore demand repeated surgery and ultimately lead to unacceptable long-term outcomes [5,6].…”