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
Control of premature corrosion of magnesium(Mg)alloy bioresorbable stents(BRS)is frequently achieved by the addition of rare earth elements.However,limited long-term experience with these elements causes concerns for ...Control of premature corrosion of magnesium(Mg)alloy bioresorbable stents(BRS)is frequently achieved by the addition of rare earth elements.However,limited long-term experience with these elements causes concerns for clinical application and alternative methods of corrosion control are sought after.Herein,we report a“built-up”composite film consisting of a bottom layer of MgF2 conversion coating,a sandwich layer of a poly(1,3-trimethylene carbonate)(PTMC)and 3-aminopropyl triethoxysilane(APTES)co-spray coating(PA)and on top a layer of poly(lactic-co-glycolic acid)(PLGA)ultrasonic spray coating to decorate the rare earth element-free Mg-2Zn-1Mn(ZM21)BRS for tailoring both corrosion resistance and biological functions.The developed“built-up”composite film shows synergistic functionalities,allowing the compression and expansion of the coated ZM21 BRS on an angioplasty balloon without cracking or peeling.Of special importance is that the synergistic corrosion control effects of the“built-up”composite film allow for maintaining the mechanical integrity of stents for up to 3 months,where complete biodegradation and no foreign matter residue were observed about half a year after implantation in rabbit iliac arteries.Moreover,the functionalized ZM21 BRS accomplished re-endothelialization within one month.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.
基金This work was supported by the National Natural Science Foundation of China(Project 32171326,82072072,81330031)the INTERNATIONAL COOPERATION Project by Science and Technology Department of Sichuan Province(2021YslnFH0056)the High-level Talents Research and Development Program of Affiliated Dongguan Hospital(K202102).
文摘Control of premature corrosion of magnesium(Mg)alloy bioresorbable stents(BRS)is frequently achieved by the addition of rare earth elements.However,limited long-term experience with these elements causes concerns for clinical application and alternative methods of corrosion control are sought after.Herein,we report a“built-up”composite film consisting of a bottom layer of MgF2 conversion coating,a sandwich layer of a poly(1,3-trimethylene carbonate)(PTMC)and 3-aminopropyl triethoxysilane(APTES)co-spray coating(PA)and on top a layer of poly(lactic-co-glycolic acid)(PLGA)ultrasonic spray coating to decorate the rare earth element-free Mg-2Zn-1Mn(ZM21)BRS for tailoring both corrosion resistance and biological functions.The developed“built-up”composite film shows synergistic functionalities,allowing the compression and expansion of the coated ZM21 BRS on an angioplasty balloon without cracking or peeling.Of special importance is that the synergistic corrosion control effects of the“built-up”composite film allow for maintaining the mechanical integrity of stents for up to 3 months,where complete biodegradation and no foreign matter residue were observed about half a year after implantation in rabbit iliac arteries.Moreover,the functionalized ZM21 BRS accomplished re-endothelialization within one month.
