Department of Paediatric and Adolescent Surgery, Medical University of Graz, Austria.
Acta Biomater. 2011 Jan;7(1):432-40. doi: 10.1016/j.actbio.2010.08.020. Epub 2010 Sep 15.
Previous research on the feasibility of using biodegradable magnesium alloys for bone implant applications mainly focused on biocompatibility and corrosion resistance. However, successful clinical employment of endosseous implants is largely dependent on biological fixation and anchorage in host bone to withstand functional loading. In the present study, we therefore aimed to investigate whether bone-implant interface strength and osseointegration of a novel biodegradable magnesium alloy (Mg-Y-Nd-HRE, based on WE43) is comparable to that of a titanium control (Ti-6Al-7Nb) currently in clinical use. Biomechanical push-out testing, microfocus computed tomography and scanning electron microscopy were performed in 72 Sprague-Dawley rats 4, 12 and 24 weeks after implantation to address this question. Additionally, blood smears were obtained from each rat at sacrifice to detect potential systemic inflammatory reactions. Push-out testing revealed highly significantly greater maximum push-out force, ultimate shear strength and energy absorption to failure in magnesium alloy rods than in titanium controls after each implantation period. Microfocus computed tomography showed significantly higher bone-implant contact and bone volume per tissue volume in magnesium alloy implants as well. Direct bone-implant contact was verified by histological examination. In addition, no systemic inflammatory reactions were observed in any of the animals. We conclude that the tested biodegradable implant is superior to the titanium control with respect to both bone-implant interface strength and osseointegration. These results suggest that the investigated biodegradable magnesium alloy not only achieves enhanced bone response but also excellent interfacial strength and thus fulfils two critical requirements for bone implant applications.
先前关于可生物降解镁合金在骨植入物应用中可行性的研究主要集中在生物相容性和耐腐蚀性上。然而，内植物在临床上的成功应用在很大程度上取决于其在宿主骨中的生物学固定和锚固，以承受功能性负荷。因此，本研究旨在探讨一种新型可生物降解镁合金（基于 WE43 的 Mg-Y-Nd-HRE）的骨-植入物界面强度和骨整合能力是否可与目前临床使用的钛对照（Ti-6Al-7Nb）相媲美。在植入后 4、12 和 24 周，通过生物力学推出试验、微焦点计算机断层扫描和扫描电子显微镜对 72 只 Sprague-Dawley 大鼠进行了研究。此外，在处死每个大鼠时获取血涂片以检测潜在的全身炎症反应。推出试验结果显示，在每个植入期后，镁合金棒的最大推出力、最终剪切强度和失效能量吸收均显著高于钛对照。微焦点计算机断层扫描显示，镁合金植入物的骨-植入物接触和骨体积/组织体积也显著更高。组织学检查证实了直接的骨-植入物接触。此外，在任何动物中均未观察到全身炎症反应。我们得出结论，与钛对照相比，所测试的可生物降解植入物在骨-植入物界面强度和骨整合方面均具有优势。这些结果表明，所研究的可生物降解镁合金不仅能增强骨反应，而且还具有优异的界面强度，从而满足骨植入物应用的两个关键要求。
