材料期刊网

近年来,镁及镁合金由于其生物可降解性和良好的生物相容性,在医疗器械领域的应用获得了迅速的发展,然而过快的降解速率限制了其在临床上的应用.可生物降解有机高分子涂层是一种降低镁及镁合金降解速率的有效表面改性方法,同时还可赋予镁及镁合金医疗器械多种功能性.首先综述了可降解有机高分子涂层对镁及镁合金耐腐蚀性能和生物相容性的影响.可降解聚合物涂层能阻碍腐蚀性介质与基体的接触,从而延长其降解时间.而涂层对基体的保护提供了碱性较弱的环境,更利于细胞的生长增殖;同时涂层随着基体一起降解,可降低聚合物长期存在生物体内可能引发炎症反应的风险.此外,对聚合物涂层在骨科以及心血管支架领域的应用以及进展进行了综述.一方面,可降解聚合物涂层能显著延长镁及镁合金在生物体内的作用时间;另一方面,涂层可以作为载体材料通过携带具有不同功能的试剂或者药物实现医疗器械的功能化,如促进骨愈合和药物的可控释放.因此,可降解聚合物涂层在镁和镁合金器械领域必将起到无可替代的作用.

In recent years,the application of Mg and Mg alloys has achieved great progress in the field of medical devices due to their biodegradability and excellent biocompatibility.However,the fast degradation of Mg and its alloys has limited the clinical application of the Mg-based medical devices.Biodegradable organic polymer coating is an effective surface modification technology to decrease the degradation rate of Mg and its alloys,and provide a variety of functional properties for them.Effects of the biodegradable polymer coating on corrosion resistance and biocompatibility of Mg-based devices were firstly reviewed.The coating could prevent corrosive medium from contacting the substrate,thus prolonging the degradation period.The coating provided alkalescent environment for substrate protection,facilitating the growth and proliferation of cells.Moreover,the coating degraded along with the substrate,which could lower the risk of inflammation reaction caused by permanent existence of polymer in vivo.Besides,the application of polymer coating in the field of orthopedics and cardiovascular stents was reviewed.The biodegradable polymer coating,on one hand,could extend the action time of Mg and its alloys in vivo;on the other hand,the biodegradability of the polymer made it an ideal carrier to carry various reagents and drugs featuring in different functions to realize distinct functions,such as promoting bone healing and controlled drug release.In summary,the biodegradable polymer coating is expected to play an irreplaceable role in Mg and Mg alloys-based medical devices.