WE43镁合金在大鼠体内的降解规律及其元素分布

Degradation pattern and element distribution of WE43 magnesium alloy implanted in rats

目的研究能够与骨形成建立良好动态重建平衡关系的降解性镁合金,探讨WE43镁合金作为骨科固定材料的可行性。方法在18只SD大鼠股骨内分别植入WE43镁合金棒(9只)及Mg-Mn合金棒(9只),术后不同时间处死动物,取肝、肾行病理分析;体视镜及扫描电镜下观察移植物/新骨界面区,并计算降解率;电子探针全扫描分析合金元素分布状态。结果两种镁合金均发生不同程度降解,WE43比Mg-Mn合金具有更好的新骨诱导性和耐腐蚀性能,两种材料降解均未对大鼠肝、肾造成不良影响。实验组WE43中的稀土元素可在大鼠股骨体周围形成少量存留,并对骨生成起促进作用,两种合金中的镁元素及Mg-Mn合金中的锰元素在大鼠股骨体周围均不形成存留。结论 WE43镁合金比Mg-Mn合金的降解速率慢,更适合与新骨重建形成良好平衡关系,是一种可降解性内固定材料。

Objective To investigate the feasibility of WE43 magnesium alloy applied as balanced degradable fixed materials in the bones of human body. Methods Both experimental WE43 and control Mg-Mn alloy rods were implanted into the same femora of 18 SD rats, which were sacrificed at different time postoperatively for hepatic and renal pathological analysis, implant/bone interface observation with stereoscope and scanning electron microscope （SEM）, degradation rate counting and elements distribution scanning. Results WE43 rods showed better corrosion resistance and osteoinductive properties than Mg-Mn , although both of them degraded simultaneously. Likewise, both materials scarcely harmed liver and kidney of rats. A few earth elements of WE43 rod remained in the new bone and could promote bone development, while Mg and Mn elemnts in whatever alloy were not existed in the peripheral bone tissue. Conclusion WE43 alloy degrades slower than Mg-Mn alloy ,which enables it to adapt to bone forming and rebuilt balance relationship between them. Therefore, WE43 is a potential biodegradable bone implant with good histocompatibility.