Study On Copper-mediated Polyphenol Coating For Cardiovascular Materials Surface Modification

Nitric oxide (NO), a molecule produced by endothelial cells of the blood vessel intima, has been found to be a potent inhibitor of platelet activation and adhesion, as well as an effective inhibitor of smooth muscle proliferation. Recent research has reported that biomaterials modified by NO donor could improve anticoagulant and antiproliferative properties by releasing NO. In the presence of the reducing agent GSH, Cu (Ⅱ) has a strong catalytic effect,having the capable of catalyzing the RSNO release NO. When applied to study cardiovascular material, it’s the currently hotspot to use copper ion as a catalyst in the production of nitric oxide.In this paper, a novel method was developed for improving anticoagulant and antiproliferative properties of inorganic materials by building a catalytic activity layer with cystamine immobilization. The catalytic activity layer can in situ induce NO releasing from endogenous NO donor.Firstly, four different feed ratios of collagen and EGCG/CA-doped copper coating were prepared, in which surface is a variety of functional groups of phenol hydroxyl group, an amide bond, an amino group, quinone group, Michael addition reaction and Seaver base reaction occurred with collagen and polyphenols, the copper was successfully loaded. Redox reaction occured between polyphenols and copper, so that Cu (Ⅱ) is reduced to Cu (Ⅰ) and Cu (0). TEM results show that not only copper (Ⅰ/Ⅱ) but also the copper nanoparticle is possible formed in the surface of collagen-polyphenols crosslinked film.The in vitro NO release experiment was used to evaluate the catalytic activity of cystamine-modified surface. The test showed that surface can effectively catalyze SNAP release NO.The platelet adhesion test and smooth muscle cells (SMC) test were used to evaluate biological properties of catalytic activity surface, the cooper- incorporated surface could inhibit platelets adhesion as well as smooth muscle cells adhesion. The endothelial cell(EC) test in vitro showed the coating had no toxic effects o on endothelial cellsIn addition,in the paper, the catechol/polyethyleneimine coating was also successfully constructed,,After three different amounts of the amino and phenolic hydroxyl surface preparing by adjusting the ratio between the two, copper was doped. Three kinds of coatings all had the catalytic activity of NO release, and with the copper content increasing, the ability to catalyze NO increased. The platelet adhesion test and smooth muscle cells (SMC) test were used to evaluate biological properties of catalytic activity surface, the surface could inhibit platelets adhesion as well as smooth muscle cells adhesion.In summary, in this paper, two different catalytically active layer was successfully constructed on the stainless steel surface. Both can catalyze NO release from endogenous NO donor. The modified surface can induce the generation of cGMP in platelet and smooth muscle cell, and inhibit platelet adhesion and activation, and prevent smooth muscle cell adhesion and proliferation.