新型可降解镁合金胆道支架的体外降解规律及力学性能

新型可降解镁合金胆道支架的体外降解规律及力学性能王金瑞，于良，师建华，王博，吕西安交通大学第一附属医院肝胆外科，陕西省西安市710061InvitrobiodegradationandmechanicalcharacteristicsofanovelbiliarystentmadeofmagnesiumalloyWangJin-rui,YuLiang,ShiJian-hua,WangBo,LvYi,HaoJieDepartmentofHepatobiliarySurgery,theFirstAffiliatedHospital,Xi’anJiaotongUniversity,Xi’an710061,ShaanxiProvince,China摘要背景：大量文献表明镁合金可在体内降解，具有优良的机械支撑性能，并且可作为血管支架材料、骨固定材料及多孔骨修复材料，但未见将其应用于胆道支架的报道。目的：评估AZ31B镁合金胆道支架在体外人胆汁中的降解过程及力学性能变化规律。方法：将AZ31B镁合金激光镂空雕刻成球囊扩张可膨式胆道支架，其中表面经微弧氧化处理的胆道支架、裸胆道支架各15枚，分别为实验组和对照组。体外建立动态数值化模拟系统，模拟人体胆道内环境，将两组支架置于模拟系统内，每20d为一个观察单位，定期观察支架的大体形态、质量及径向支撑力，扫描电镜观察支架表面形态。结果与结论：①实验组较对照组降解速度明显减慢，对照组20d开始出现连杆的断裂，降解高峰在30d左右，70d内完全降解；实验组40d开始出现连杆的断裂，降解高峰在50d左右，90d内完全降解。两组随着降解时间的延长，支架表面变得粗糙，蚀坑的密度增加，蚀坑的面积增大，蚀坑的深度加大。在相同阶段，对照组相对于实验组降解程度明显严重。②实验组与对照组支架的质量及径向支撑力随降解时间的延长逐渐下降，实验组较对照组下降速度明显减慢。表明AZ31B镁合金胆道支架经过表面微弧氧化处理后降解速度适宜，能够达到临床上对胆道支架降解时间的要求。中国组织工程研究杂志出版内容重点：生物材料；骨生物材料;口腔生物材料;纳米材料;缓释材料;材料相容性；组织工程全文链接：关键词：生物材料；材料相容性；镁合金；胆道支架；生物可降解；径向支撑力；Abstract：BACKGROUND:Numerousevidencehasdemonstratedthatthemagnesiumalloywithexcellentmechanicalpropertiescandegradeinvivo,andcanbeusedasvascularstentmaterials,bonefixationmaterials,porousmaterialsforbonerepair.Butitisnotreportedinthebiliarystent.OBJECTIVE:Toobservethedegradationproceduresandevaluatethechangesofmechanicalcharacteristicsofbiliarystentsmadeofmagnesiumalloy(AZ31B)inhumanbileinvitro.METHODS:Theballoon-expandablebiliarystentsweremadeofmagnesiumalloywithlasersculpture.Then,15stentstreatedwithmicro-arcoxidationonthesurfaceservedasexperimentalgroupandanother15stentswithoutmicro-arcoxidationascontrolgroup.Adynamicnumericalsimulationsystemwasestablishedinvitrotosimulatetheinternalenvironmentofhumanbiliarytract.Allofthebiliarystentswereplacedintothissystem.Theirshapeswereobserved,andtheirqualitiesandradicalforcesweremeasuredevery20days.Atthesametime,theirsurfaceswerescannedbyscanningelectronmicroscope.RESULTSANDCONCLUSION:(1)Thedegradationspeedsofthestentsintheexperimentalgroupwereobviouslyslowerthanthoseinthecontrolgroup.Thefractureoftheconnectingrodsincontrolgroupandexperimentalgroupappeared20daysand40dayslater,respectively.Thepeaktimeofdegradationinthecontrolgroupandexperimentalgroupwere30daysand50days,respectively.Thestentswerefullybiodegradedwithin70daysinthecontrolgroupwhilewithin90daysintheexperimentalgroup.Withtime,thestentsurfacebecamemorerough,andthedensity,areaanddepthofetchpitswereallincreasedinthetwogroups.Atthesamestage,thedegradationspeedofthecontrolgroupwasmorerapidthanthatintheexperimentalgroup.(2)Thequalitiesandradicalforcesofthestentsweregraduallyreducedwithtimeinbothgroups.However,thedegradationspeedofstentsintheexperimentalgroupwasmuchslowerthanthatinthecontrolgroup.Insummary,thedegradationspeedofthebiliarystentsmadeofmagnesiumalloytreatedwithmicro-arcoxidationisappropriateandcanmeettheclinicalrequirementforthedegradationtimeofbiliarystents.Thisnovelmaterialcouldpotentiallybeusedforthepreparationofbiliarystents.中国组织工程研究杂志出版内容重点：生物材料；骨生物材料;口腔生物材料;纳米材料;缓释材料;材料相容性；组织工程全文链接：Keywords：biocompatiblematerials;magnesium;biliarytract;histocompatibility;收稿日期:2014-04-11中图分类号:R318基金资助:陕西省科技统筹创新工程计划项目(2011KTCL03-21)通讯作者:于良，博士，教授，硕士生导师，西安交通大学第一附属医院肝胆外科，陕西省西安市710061作者简介:王金瑞，男，1985年生，山东省滨州市沾化县人，汉族，西安交通大学在读硕士，主要从事胆道微创治疗研究。引用本文:.新型可降解镁合金胆道支架的体外降解规律及力学性能[J].中国组织工程研究,2014,18(25):3980-3986..Invitrobiodegradationandmechanicalcharacteristicsofanovelbiliarystentmadeofmagnesiumalloy[J].ChineseJournalofTissueEngineeringResearch,2014,18(25):3980-3986.