Department of Materials Engineering, Ben-Gurion University of the Negev, Beer-Sheva, Israel.
Department of Mechanical Engineering, Sami Shamoon College of Engineering, Beer-Sheva, Israel.
Ann Biomed Eng. 2020 Jan;48(1):380-392. doi: 10.1007/s10439-019-02355-5. Epub 2019 Sep 17.
Mg-based alloys have been considered as potential structural materials for biodegradable implants in orthopedic and cardiovascular applications, particularly when combined with other biocompatible alloying elements. However, the performances of Mg-based alloys in in vitro conditions do not accurately reflect their behavior in an in vivo environment. As such, the present study aimed at evaluating the in vivo behavior of a novel Mg-5Zn-2Nd-0.13Y-0.35Zr alloy designated as ZE52 alloy. In vivo assessment was carried out using cylindrical disks implanted into the sub-cutaneous layer of the skin at the back midline of male Wistar rats for up to 11 weeks. Post-implantation responses evaluated included well-being behavior, blood biochemical tests and histology. The corrosion rate of the implants, expressed in terms of hydrogen gas formation, was evaluated by radiographic assessment and CT examination. Results of the well-being behavioral and blood biochemical tests indicated that the in vivo behavior of ZE52 alloy implants was similar to that of inert Ti-6Al-4V alloy implants introduced into a control group. Moreover, histological analysis did not reveal any severe inflammation, as compared to the reference alloy. However, significant sub-cutaneous gas cavities were observed, indicative of the accelerated degradation of the ZE52 alloy implants. The accelerated degradation was also manifested by the formation of alloy debris that was encapsulated within the gas cavities. Post-implantation gas bubble puncturing resulted in the complete degradation of the Mg-based implants, indicating that the inert nature of the gas prevented accelerated degradation of the alloy before it was naturally absorbed by the body.
镁基合金已被认为是骨科和心血管应用中可生物降解植入物的潜在结构材料，特别是与其他生物相容性合金元素结合使用时。然而，镁基合金在体外条件下的性能并不能准确反映其在体内环境中的行为。因此，本研究旨在评估一种新型 Mg-5Zn-2Nd-0.13Y-0.35Zr 合金（命名为 ZE52 合金）的体内行为。体内评估是通过将圆柱形圆盘植入雄性 Wistar 大鼠背部中线的皮下层来进行的，时间长达 11 周。植入后的反应评估包括行为表现、血液生化测试和组织学检查。通过射线照相评估和 CT 检查评估植入物的腐蚀速率，以氢气形成的形式表示。体内行为和血液生化测试的结果表明，ZE52 合金植入物的体内行为与引入对照组的惰性 Ti-6Al-4V 合金植入物相似。此外，与参考合金相比，组织学分析并未发现任何严重的炎症。然而，观察到明显的皮下气体腔，表明 ZE52 合金植入物的加速降解。加速降解还表现为形成被气体腔包裹的合金碎屑。植入后气泡穿孔导致基于 Mg 的植入物完全降解，表明惰性气体在被身体自然吸收之前阻止了合金的加速降解。
