Construction And Performance Investigation Of Biomimetic Basement Membrane Extracellular Matrix On ZE21B Alloy

Cardiovascular disease is the number one killer that threatens human’s health,and vascular stent implantation is one of the most effective methods to cure it at present.Magnesium alloy vascular stents have excellent mechanical support properties and biodegradability,and have broad clinical application prospect.However,the rapid degradation rate and insufficient biocompatibility severely restrict the clinical use of magnesium alloy vascular stents.In order to improve the biocompatibility of magnesium alloys,this study firstly prepared a biomimetic basement membrane extracellular matrix by regulating the physiological phenotypes of vascular smooth muscle cells and endothelial cells by surface hyaluronic acid micropatterns and sequentially decellularized cells.Then the extracellular matrix(ECM)suspension was obtained by sonication.Finally,the ECM in suspension was grafted onto the surface of degradable Mg-Zn-Y-Nd(ZE21B)alloy by using a self-assembly method.Three different ECM samples(ECM-6 h sample,ECM-12 h sample and ECM-24 h sample)were obtained by controlling the self-assembly time.(1)In this study,the characterization of the morphology,element content,functional group changes,and valence states of the samples were conducted by SEM,FTIR and XPS,and it demonstrated ECM were successfully grafted.The water contact angle test results showed that the ECM samples had better hydrophilicity,and the water contact angle decreased with the extension of the self-assembly time.The roughness test results showed that the roughness of the ECM samples was larger than that of the ZE21 B alloy,which is more conducive to cell adhesion.By analyzing the distribution of the two main components(COL IV and FN)in the ECM on the samples,it was found that ECM distributed on the ECM-12 h and ECM-24 h samples was larger.As the selfassembly time was longer,ECM was more uniformly distributed on the surface of the sample.(2)In this study,the results of electrochemical and weight loss experiments showed that there was no statistically significant difference in the corrosion rate of ECM samples.The results of corrosion product and corrosion morphology experiments showed that the corrosion resistance of the ECM-12 h and ECM-24 h samples was better than that of ECM-6 h sample during long-time soaking.(3)In this study,the results of vitro blood experiments showed that the ECM-24 h sample had a low degree of platelet activation and a small number of platelet adhesion.At the same time,the hemolysis rate,blood component adhesion,and fibrinogen adhesion and degeneration showed lower levels.(4)In this study,the results of endothelial cells culture experiments showed that ECM-24 h sample had the best reendothelialization function and the ability to continuously release functional factor NO.The results of smooth muscle cells culture experiments showed that the ECM-24 h sample had the best anti-proliferative ability and could inhibit smooth muscle cells proliferation by regulating the smooth muscle cells’ phenotype to contractile type.The results of the competitive culture of endothelial cells and smooth muscle cells showed that endothelial cells had the most obvious competitive growth advantage on ECM-24 h sample.The results of macrophages culture experiments showed that the ECM group samples had better anti-inflammatory function.In conclusion,the ECM-24 h sample has excellent blood compatibility,the functions of promoting reendothelialization,anti-proliferation and anti-inflammatory,and can improve the corrosion resistance of magnesium alloys.This biomimetic basement membrane extracellular matrix modification strategy provides a new idea for the design and development of magnesium alloy vascular stents.