Abstract

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.

中文翻译：

---

Mg–5％Zn–2％Nd合金作为一种创新的可生物降解植入材料的体内评估

摘要

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。但是，镁基合金在体外条件下的性能不能准确反映其在体内环境下的行为。因此，本研究旨在评估称为ZE52合金的新型Mg-5Zn-2Nd-0.13Y-0.35Zr合金的体内行为。体内使用圆柱形圆盘植入雄性Wistar大鼠后中线皮肤皮下层进行长达11周的评估。评估的植入后反应包括健康行为，血液生化测试和组织学。植入物的腐蚀速率以氢气形成的形式通过射线照相评估和CT检查进行评估。健康行为和血液生化测试的结果表明，体内ZE52合金植入物的行为类似于引入对照组的惰性Ti-6Al-4V合金植入物的行为。而且，与参考合金相比，组织学分析没有发现任何严重的炎症。但是，观察到明显的皮下气体腔，这表明ZE52合金植入物的加速降解。加速降解还通过包封在气体腔内的合金碎屑的形成来证明。植入后的气泡刺穿导致基于Mg的植入物完全降解，表明气体的惰性性质阻止了合金在被人体自然吸收之前加速降解。