ABSTRACT
Cardiovascular diseases (CVDs) cover a range of conditions affecting both the heart and the blood vessels, and are a major health problem that results in substantial morbidity and death worldwide due to dysfunctional or diseased valve, atherosclerosis, narrowing of the arteries and small blood vessels by plaque deposition, and aging of the population [2-5]. Therefore, the improved healthcare has become a great need of the hour. Currently, there are several treatment options for blocked blood vessels such as angioplasty, stenting, thrombolysis, and surgical bypass. While these treatments are well established, they have their inherent limitations and complications and also typically do not regenerate the damaged organs. Therefore, there is a need to develop new strategies for regenerating tissue following ischemia [6]. Although various commercial cardiovascular implants include processed biological substances (collagen and heparin), metals (titanium, stainless steel, nitinol, cobalt-chrome alloys, etc.) and polymeric biomaterials (polytetrauorethylene, polyethylene terephthalate, polyurethane, polyvinyl chloride, etc.) have been approved by Food and Drug Administration (FDA) as effective implants and graft materials and millions of patients benet from these products. Both synthetic and natural polymers have been trialed, though each has its own limitations. While the former allows easy processing and modications, the later offers better cyto-and biocompatibility [3]. However, there is still need for an ideal device that can help patients who are suffering from CVDs because cardiovascular system consists of the heart and all the blood vessels, and cardiovascular biomaterials may contact blood (both arterial and venous), vascular endothelial cells, broblasts, and myocardium, as well as a number of other cells and a cellular matrix material that make up all biological tissue and may provoke coagulation and platelet activation. Therefore, the foremost requirements for biomaterials used in contact with blood include prevention of the coagulation cascade and platelet activation. Now, most permanently implanted cardiovascular devices are designed to treat underlying medical conditions or provide enhanced functions. However, the main causes of failure of cardiovascular devices are excessive growth of the tissues surrounding the device, thrombosis (clots may occlude the device or may occlude small blood vessels, resulting in heart attacks, strokes, paralysis, failures of other organs, etc.), damage blood cells, and hemolysis (occur as a reaction to the material surface and the blood) that necessitate reoperation or cause morbidity or death. Cardiovascular biomaterials may also in contact with other tissues. Cardiovascular biomaterials, either temporary or permanent devices, can be divided into three categories: temporary external devices (simple tubing for bypass or hemodialysis, oxygenators, arterial lters, and hemodialysis equipment), temporary internal devices (catheters, guide wires, and cannulae used in bypass circuits), and permanent internal devices (pacemakers, debrillators, stents, left ventricular assist devices, and articial hearts) [7-11].
