A multifunctional endothelial-mimetic surface: Synergistically combating thrombus formation by releasing nitric oxide, promoting fibrinolysis, and enhancing endothelialization

Thrombus formation often leads to the failure of intravascular implants. Natural endothelium provides multifaceted antithrombotic functions through nitric oxide/ prostacyclin secretion to inhibit platelet activation, glycosaminoglycan mediated anticoagulation, and tissue-type plasminogen activator driven fibrinolysis. Therefore, surfaces mimicking these multiple endothelial functions are expected to have enhanced antithrombotic properties. In this study, polyvinyl chloride surface was rendered porous through solvent/nonsolvent-induced phase separation and loaded with a metal-organic framework, CuBTTri to catalyze nitric oxide release from a precursor. Furthermore, using layer-by-layer self-assembly, multiple bilayers of a poly(lysine- co -oligo(ethylene glycol) methyl ether methacrylate) copolymer (fibrinolysis-promoting), and sodium heparin (endothelial cell growth-promoting), were deposited on the un-etched side of the polyvinyl chloride. This modified surface was shown to be capable of releasing nitric oxide, destroying nascent thrombus, inhibiting smooth muscle cell growth, and promoting endothelial cell adhesion. This study represents a novel approach to developing multifunctional blood-contacting surfaces that mimic multiple properties of the endothelium.