Nitric Oxide Donors for Cardiovascular Implant Applications

In an era of increased cardiovascular disease burden in the ageing population, there is great demand for devices that come in to contact with the blood such as heart valves, stents, and bypass grafts that offer life saving treatments. Nitric oxide (NO) elution from healthy endothelial tissue that lines the vessels maintains haemostasis throughout the vasculature. Surgical devices that release NO are desirable treatment options and N‐diazeniumdiolates and S‐nitrosothiols are recognized as preferred donor molecules. There is a keen interest to investigate newer methods by which NO donors can be retained within biomaterials so that their release and kinetic profiles can be optimized. A range of polymeric scaffolds incorporating microparticles and nanomaterials are presenting solutions to current challenges, and have been investigated in a range of clinical applications. This review outlines the application of NO donors for cardiovascular therapy using biomaterials that release NO locally to prevent thrombosis and intimal hyperplasia (IH) and enhance endothelialization in the fabrication of next generation cardiovascular device technology. Small‐diameter bypass grafts occlude in the absence of NO, resulting in platelet adhesion, smooth muscle cell (SMC) proliferation and migration from the site of anastomosis, causing repeat episodes of thrombosis and intimal hyperplasia leading to graft failure. The presence of NO‐eluting micro‐ or nanoparticles within the vascular graft provides an environment similar to the natural vessel by inhibiting thrombus formation and SMC proliferation to prevent graft failure.