In vitro and in vivo studies on a Mg-Sr binary alloy system developed as a new kind of biodegradable metal
In vitro and in vivo studies on a Mg-Sr binary alloy system developed as a new kind of biodegradable metal
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作为一种新型可生物降解金属开发的 Mg-Sr 二元合金系统的体外和体内研究
DOI：
10.1016/j.actbio.2012.02.018
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发表时间：
2012-07-01
影响因子：
9.7
通讯作者：
Qin, L.
中科院分区：
文献类型：
--
作者：
Gu, X. N.;Xie, X. H.;Qin, L.
镁合金由于其可降解性、与皮质骨的相似性和生物相容性降解/腐蚀产物而显示出作为骨科应用的可生物降解金属材料的潜力。然而，镁合金的快速腐蚀和合金元素的潜在毒性限制了镁合金的临床应用。从冶金学和生物相容性两方面考虑，选择Sr（Sr）制备热轧Mg-Sr二元合金（Sr含量为1 ~ 4 wt.%）在本研究中。通过体外细胞实验和髓内植入实验，筛选出了最佳Sr含量，并对Mg-Sr二元合金的力学性能和腐蚀性能进行了研究，探讨了Mg-Sr合金作为骨科生物降解金属的可行性。Mg-Sr合金的力学性能和腐蚀速率与添加的Sr含量有关。轧制态Mg-2Sr合金的强度最高，腐蚀速率最慢，表明最佳Sr含量为2 wt.%。轧制态Mg-2Sr合金显示出I级细胞毒性，并诱导出比其他合金更高的碱性磷酸酶活性。在4周植入期间，我们观察到轧制Mg-2Sr合金在骨隧道内逐渐降解。微型计算机断层扫描和组织学分析显示，实验种植体周围的矿物质密度增加，皮质骨变厚。与对照组相比，在新形成的笔式种植体骨中观察到更高水平的Sr。综上所述，本研究表明，添加的Sr的最佳含量为2 wt.%对于轧制状态的二元Mg-Sr合金，轧制态Mg-2Sr合金在体内产生可接受的宿主反应。(C)2012 Acta Materialia Inc.由爱思唯尔有限公司出版。保留所有权利。
Magnesium alloys have shown potential as biodegradable metallic materials for orthopedic applications due to their degradability, resemblance to cortical bone and biocompatible degradation/corrosion products. However, the fast corrosion rate and the potential toxicity of their alloying element limit the clinical application of Mg alloys. From the viewpoint of both metallurgy and biocompatibility, strontium (Sr) was selected to prepare hot rolled Mg-Sr binary alloys (with a Sr content ranging from 1 to 4 wt.%) in the present study. The optimal Sr content was screened with respect to the mechanical and corrosion properties of Mg-Sr binary alloys and the feasibility of the use of Mg-Sr alloys as orthopedic biodegradable metals was investigated by in vitro cell experiments and intramedullary implantation tests. The mechanical properties and corrosion rates of Mg-Sr alloys were dose dependent with respect to the added Sr content. The as-rolled Mg-2Sr alloy exhibited the highest strength and slowest corrosion rate, suggesting that the optimal Sr content was 2 wt.%. The as-rolled Mg-2Sr alloy showed Grade I cytotoxicity and induced higher alkaline phosphatase activity than the other alloys. During the 4 weeks implantation period we saw gradual degradation of the as-rolled Mg-2Sr alloy within a bone tunnel. Micro-computer tomography and histological analysis showed an enhanced mineral density and thicker cortical bone around the experimental implants. Higher levels of Sr were observed in newly formed pen-implant bone compared with the control. In summary, this study shows that the optimal content of added Sr is 2 wt.% for binary Mg-Sr alloys in the rolled state and that the as-rolled Mg-2Sr alloy in vivo produces an acceptable host response. (C) 2012 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.