Construction and biocompatibility evaluation of MOF/S-HA composite coating on the surface of magnesium alloy vascular stent

In recent years, functional molecules such as metal-organic frameworks (MOFs), hyaluronic acid (HA) and heparin have been widely studied in the field of surface modification of cardiovascular and cerebrovascular implant materials. However, magnesium (Mg) alloy scaffolds, which are used as implanted materials, have difficulties such as poor cell compatibility, insufficient endothelialization, and remodeling of the blood-brain barrier. In this study, MOF-Cu formed after chelating organic ligand catechol (HPT) and Cu(II) was coated by Sulfonated hyaluronic acid (S-HA) on the surface of ZE21B Mg alloy to form a composite coating, which not only inherited the excellent anticoagulant and anti-inflammatory properties of S-HA, but also significantly improved the bio-compatibility of the coating by reasonably regulating the concentration of Nitric oxide (NO) catalytic release, promoted the proliferation, migration and expression of specific factors in endothelial cells (ECs), regulated the transformation of smooth muscle cells (SMCs) to contractile phenotypes. And it has important and remarkable performance in promoting the transformation of macrophage (MA) into anti-inflammatory M2 phenotype. These results provide important research strategies for Mg alloy vascular stents materials in remodeling blood-brain barrier, relaxing cerebrovascular vessels, inhibiting inflammatory responses, and maintaining cardiovascular and cerebrovascular elasticity.