Rare-earth-free magnesium(Mg)alloy bioresorbable stent(BRS)exhibits significant potential in vascular intervention due to its exceptional biosafety.However,its susceptibility to corrosion complicates surface func-tion...Rare-earth-free magnesium(Mg)alloy bioresorbable stent(BRS)exhibits significant potential in vascular intervention due to its exceptional biosafety.However,its susceptibility to corrosion complicates surface func-tionalization and renders existing coating strategies ineffective for degradation-remodeling kinetics,resulting in delayed re-endothelialization and excessive lumen loss.Herein,a hierarchical MgF_(2)/polyurethane(PU)/pit-avastatin(PTV)coating system is constructed on Mg-Zn-Mn BRS using elastomeric PU as an intermediate layer.Studies confirm the PU layer effectively accommodates stent deformation,alleviates stress concentrations,and confines corrosion propagation triggered by deformation-induced MgF_(2) microcracks.The in situ formed MgF_(2) layer concurrently decreases substrate reactivity,establishes stable interfaces with PU,and synergistically en-hances the corrosion resistance.The surface PTV-loaded poly-L-lactic acid layer maintains sustained drug release through PU-mediated interfacial stability while serving as an initial corrosion barrier.In vivo evaluations demonstrate the MgF_(2)/PU/PTV-functionalized stent significantly suppresses neointimal hyperplasia in rabbit models while achieving synchronized degradation-remodeling kinetics.This hierarchical coating architecture,which synergistically integrates controlled drug elution with degradation modulation,provides a viable solution to clinical challenges of post-implant restenosis and vascular remodeling mismatch.展开更多
基金supported by Natural Science Foundation of China(Project 32171326,32371377,32471376,32261160372)the Post-doctoral Fellowship Program(Grade C)of China Postdoctoral Science Foundation(Grant Number GZC20240667)+3 种基金The Third People’s Hospital of Chengdu Scientific Research Project(2023PI06)the Guang Dong Basic and Applied Basic Research Foundation(2022B1515130010)Dongguan Science and Technology of Social Development Program(20231800906311)the Leading Talent Project of Guangzhou Development District(2020-L013).
文摘Rare-earth-free magnesium(Mg)alloy bioresorbable stent(BRS)exhibits significant potential in vascular intervention due to its exceptional biosafety.However,its susceptibility to corrosion complicates surface func-tionalization and renders existing coating strategies ineffective for degradation-remodeling kinetics,resulting in delayed re-endothelialization and excessive lumen loss.Herein,a hierarchical MgF_(2)/polyurethane(PU)/pit-avastatin(PTV)coating system is constructed on Mg-Zn-Mn BRS using elastomeric PU as an intermediate layer.Studies confirm the PU layer effectively accommodates stent deformation,alleviates stress concentrations,and confines corrosion propagation triggered by deformation-induced MgF_(2) microcracks.The in situ formed MgF_(2) layer concurrently decreases substrate reactivity,establishes stable interfaces with PU,and synergistically en-hances the corrosion resistance.The surface PTV-loaded poly-L-lactic acid layer maintains sustained drug release through PU-mediated interfacial stability while serving as an initial corrosion barrier.In vivo evaluations demonstrate the MgF_(2)/PU/PTV-functionalized stent significantly suppresses neointimal hyperplasia in rabbit models while achieving synchronized degradation-remodeling kinetics.This hierarchical coating architecture,which synergistically integrates controlled drug elution with degradation modulation,provides a viable solution to clinical challenges of post-implant restenosis and vascular remodeling mismatch.
