Preparation And Properties Of Organometallic Network Coating Based On Protocatechualdehyde

Vascular stent implantation for the treatment of cardiovascular diseases as one of the important methods has been widely used clinically,but complications such as late thrombosis and in-stent restenosis caused by implantation limit its wider application.How to hinder the occurrence of complications of vascular stent implantation has become an important clinical issue.Surface modification of vascular stent materials is one of the effective means to improve its biocompatibility and effectively inhibit the occurrence of complications after implantation.Previous studies have shown that protocatechualdehyde is one of the active ingredients extracted from the commonly used traditional chinese medicine Salvia Miltiorrhiza.It can dilate coronary arteries,increase coronary blood flow and has anticoagulant effects.Due to the excellent physiological functions of protocatechualdehyde,a functional coating of DBTA organic conversion based on protocatechualdehyde was prepared by the chemical reaction principle of polyphenols,and a tripod polyphenol compound was synthesized.Finally,based on the previous research,an organometallic network coating was successfully prepared,which can load copper ions and effectively catalyze the release of nitric oxide.The physical and chemical properties and biological performance of the coating were systematically explored,and its application potential for surface modification of stent materials was discussed in depth.It is expected that the relevant research will provide new ideas for the preparation of multifunctional stent coatings.In this thesis,the DBTA organic conversion functional coating was prepared by Michael addition and Schiff base reaction between protocatechualdehyde(DBA)and tris(2-aminoethyl)amine(TAEA),and the coating construction of different solvents was investigated.The coating has been characterized by FTIR,XPS,surface amino quantification,and so on.Platelet adhesion and activation experiments show that the blood compatibility of the DBTA coating remains to be improve.Further,a one-pot synthesis method was used to synthesize a tripod polyphenol compound(TEC)based on DBA and TAEA.The organic functional coating with nitric oxide catalytic ability was constructed by the chelation of catechol and copper ion.The stability,morphology and composition of the coating were investigated by UV-spectrometer,FTIR,scanning electron microscope,XPS.The NO release experiment showed that the catalytic release rate of NO from TEC-Cu coatings was higher than that of normal endothelial cells with different copper content.The culture experiments of endothelial cells,smooth muscle cells and macrophages show that TEC-Cu can promote the adhesion and proliferation of endothelial cells,effectively inhibit the adhesion and proliferation of smooth muscle,and has anti-inflammatory properties.Hemocompatibility experiments show that all TEC-Cu samples can significantly inhibit the adhesion and activation of platelets,and can significantly prolong the partial thromboplastin time(APTT),which has an anticoagulant effect.The antibacterial performance test results show that the TEC-Cu sample has an antibacterial effect on Staphylococcus aureus and Escherichia coli.In summary,based on the chemical principles of polyphenols,this thesis uses the chemical interaction between catechins,polyamines and the surface of the metal substrate to prepare a DBTA coating rich in functional groups.A three-legged Schiff base polyphenol compound was designed and synthesized.The metal-polyphenol network coating(TEC-Cu)was constructed using the chelation effect of polyphenols and copper ions.This coating can significantly catalyze the release of NO,and exhibits promotion of endothelium,anti-smooth muscle proliferation,anti-inflammatory,anti-coagulation and antibacterial functions,which provides a new idea for the surface modification of vascular stents.