Dou Zhenglong, Chen Shuiling, Wang Jiacheng, Xia Li, Maitz Manfred F, Tu Qiufen, Zhang Wentai, Yang Zhilu, Huang Nan
Key Lab of Advanced Technology of Materials of Education Ministry, School of Materials Science and Engineering, Southwest Jiaotong University, Chengdu, 610031, China.
Max Bergmann Center of Biomaterials Dresden, Leibniz Institute of Polymer Research Dresden, Hohe Strasse 6, 01069, Dresden, Germany.
Bioact Mater. 2023 Feb 8;25:223-238. doi: 10.1016/j.bioactmat.2023.02.004. eCollection 2023 Jul.
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 MgF 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.
镁（Mg）合金生物可吸收支架（BRS）的过早腐蚀控制通常通过添加稀土元素来实现。然而，这些元素的长期经验有限，引发了对临床应用的担忧，因此人们在寻求其他腐蚀控制方法。在此，我们报告一种“叠加式”复合膜，其底层为MgF转化涂层，中间夹层为聚（1,3-三亚甲基碳酸酯）（PTMC）和3-氨丙基三乙氧基硅烷（APTES）共喷涂涂层（PA），顶层为聚（乳酸-乙醇酸共聚物）（PLGA）超声喷涂涂层，用于修饰不含稀土元素的Mg-2Zn-1Mn（ZM21）BRS，以同时调整其耐腐蚀性和生物学功能。所开发的“叠加式”复合膜显示出协同功能，使涂覆的ZM21 BRS在血管成形术球囊上压缩和扩张时不会出现破裂或剥落。特别重要的是，“叠加式”复合膜的协同腐蚀控制效果使支架的机械完整性能够维持长达3个月，在植入兔髂动脉约半年后观察到完全生物降解且无异物残留。此外，功能化的ZM21 BRS在1个月内完成了再内皮化。
