Metal-phenolic-(amine)surface Chemistry For Generating Nitric Oxide On Biodegradable Polymer Matrix Vascular Stent Coating

Cardiovascular disease(CVDS)is a common disease in modern human society,and interventional therapy is the most extensive,rapid,effective and minimally invasive treatment for CVDS.Bare metal stents(BMS)may cause harmful ion dissolution and poor biocompatibility,which can easily lead to complications such as late thrombus and restenosis.Drug-eluting stents(DES)can inhibit the abnormal proliferation of smooth muscle cells by releasing drugs,but at the same time,they also inhibit the growth of endothelial cells and delay the process of endothelialization.Polysanyanmethyl carbonate(PTMC)has a broad application prospect in the surface modification of degradable implanted instruments such as vascular stents due to its surface solubility,excellent biocompatibility and drug slow release,and has potential value in the protection of degradable metal stents and drug loading.However,PTMC is relatively hydrophobic,and its biological function cannot meet the needs of vascular stents for multiple functions such as anticoagulation,inhibition of smooth muscle cell proliferation,and promotion of endothelial regeneration.Moreover,the functional coating for the catalytic release of nitric oxide(NO)based on metal-phenol surface chemistry has been proven to successfully catalyze the release of NO when applied to the surface modification of vascular stents.It has multiple biological functions such as anticoagulation,inhibition of smooth muscle cell proliferation and promotion of endothelial regeneration.However,it has not been reported whether the NO catalytic release coating can be applied to the surface modification of degradable PTMC materials.Therefore,in this study,the spin coating method was used to first prepare the PTMC coating on the surface of the material,and then based on the metal-phenol surface chemistry,gallic acid(GA)and selenocystamine(Se CA)were covalently combined to form a network structure.Using Cu²⁺as a crosslinking agent to crosslink the above network structure,explore the construction of a NO catalytic coating with Cu^II-GA/Se CA network structure on the surface of PTMC coating,and explore the possibility of NO catalytic release coating applied to PTMC surface modification,in order to construct degradable metal stents with catalytic release of NO and PTMC corrosion protection,such as magnesium alloy stents,preliminary exploratory work has been done.The results showed that Cu^II-Ga/Seca coating was successfully constructed on PTMC coating surface by means of infrared spectroscopy,XPS,and water contact Angle,and the catalytic release rate of NO was regulated in the range of 2-6.2×10^-10 mol×cm^-2×min^-1,owing to the broad spectrum material adhesion characteristics of GA polyphenol.The systematic blood compatibility experiments showed that the catalytic release of NO inhibited platelet adhesion and activation by specifically upregulating the expression of platelet ring guanosine phosphate(c GMP),which confirmed that the NO-catalytic release coating based on metal-phenol surface chemistry could be applied to the surface modification of degradable polymer coating.The results of blood circulation experiment showed that the coating had excellent anticoagulant ability.The cytocompatibility evaluation showed that Cu^II-GA/Se CA coating could significantly inhibit the adhesion and proliferation of smooth muscle cells by catalyzing the release of NO,and promote the growth of endothelial cells.