Promoting Endothelialization of Polymeric Cardiovascular Biomaterials

Abstract

The lack of a blood compatible synthetic interface is one of the largest unaddressed challenges in the field of biomaterials science. This technological shortcoming hinders the successful clinical application of small diameter vascular grafts and other cardiovascular devices such as stents and artificial heart valves. Therefore, intensive research activities are ongoing to develop polymer materials with improved blood compatibility. One attractive strategy to improve the blood compatibility of an interface is to design surfaces that promote the development of an endothelium, the monolayer of endothelial cells that line our native vasculature and is responsible for blood compatibility. This article describes the recent strategies that have been used to generate polymeric materials that promote the development of an endothelium, discusses shortcomings in the field, and proposes future directions of research that can be undertaken to design next generation polymeric biomaterial that promote endothelialization.

Preparation of Small‐Diameter Tissue‐Engineered Vascular Grafts Electrospun from Heparin End‐Capped PCL and Evaluation in a Rabbit Carotid Artery Replacement Model

“…As complete endothelialization is essential for long‐term patency of vascular grafts, there was an endothelial layer observed on the lumen of the grafts after 1 month, and it became more obvious after 2 months of implantation, which was detected by CD31 as a marker of endothelial cells (Figure ). This is because a steady release of grafted heparin and an existence of glycocalyx structure reduced the occurrence of anticoagulation incidents and can also capture either vascular progenitor cells or differentiate vascular cells and even promote the rapid formation of endothelial layer …”

Endothelialization mechanisms in vascular grafts

“…An alternative approach is coating the surface with adhesion peptide sequences (de Mel et al, ; Heath, ; Melchiorri et al, ; Ren et al, ). Active peptide sequences have simpler structures and high stability; however, it might promote nonspecific cell adhesion (Heath, ; Hersel, Dahmen, & Kessler, ; Melchiorri et al, ; Ren et al, ). One of the most employed sequences is arginine‐glycine‐aspartic acid, which has demonstrated to increase cellular adhesion and proliferation (Ren et al, ), but its broad integrin binding affinity and selectivity might poses issues related to a lacking of EC specificity, increasing thrombosis or intimal hyperplasia (Hersel et al, ).…”

The Surface Modification Methods for Constructing Polymer-Coated Stents

“…To tackle these challenges, the concept of drugeluting stents (DESs) was introduced to restrain the occurrence of restenosis and thrombosis by allowing the release of the drug to be gradual and permitting the drug delivery to be sustained over many weeks [3,16]. Though DESs have achieved great success, material-related problems still exist in the treatment of cardiovascular diseases [17]. An outstanding problem is the lack of blood compatibility, in other words, when these stent implantation devices are confronted to blood directly, the accumulation of a blood clot or thrombus occurs on the surface of these devices [17,18].…”

“…An outstanding problem is the lack of blood compatibility, in other words, when these stent implantation devices are confronted to blood directly, the accumulation of a blood clot or thrombus occurs on the surface of these devices [17,18]. In some cases, the thrombus can directly impair the function of the device, or a piece of the thrombus can embolize and cause life-threatening problem downstream [17]. For these, many functional surfaces of implantation devices with nonfouling chemical groups [19] and/or anticoagulants [20] have been devoted to improve the blood compatibility of biomaterials, suppressing the protein and platelet deposition.…”

“…Though DESs have achieved great success, material-related problems still exist in the treatment of cardiovascular diseases [17]. An outstanding problem is the lack of blood compatibility, in other words, when these stent implantation devices are confronted to blood directly, the accumulation of a blood clot or thrombus occurs on the surface of these devices [17,18]. In some cases, the thrombus can directly impair the function of the device, or a piece of the thrombus can embolize and cause life-threatening problem downstream [17].…”