Small Animal Clinic, University of Veterinary Medicine Hannover, Buenteweg 9, 30559 Hannover, Germany.
Acta Biomater. 2013 Nov;9(10):8548-60. doi: 10.1016/j.actbio.2012.08.028. Epub 2012 Aug 23.
Magnesium alloys are the focus of research as resorbable materials for osteosynthesis, as they provide sufficient stability and would make surgery to remove implants unnecessary. The new degradable magnesium alloy ZEK100 was developed to improve the stability and corrosion resistance by alloying with zinc, rare earth metals and zirconium. As the implants were degraded to only a limited extent after 6 months implantation in a previous in vivo study the present study was conducted to evaluate the long-term degradation behaviour and biocompatibility in the same animal model over 9 and 12 months. Five rabbits each with intramedullary tibia implants were examined over 9 and 12 months. Three legs were left without an implant to serve as negative controls. Numerous examinations were performed in the follow-up (clinical examinations, serum analysis, and radiographic and in vivo micro-CT investigations) and after death (ex vivo micro-CT, histology, and implant analysis) to assess the in vivo degradation and biocompatibility. It could be shown that favourable in vivo degradation behaviour is not necessarily associated with good biocompatibility. Although ZEK100 provided a very high initial stability and positive biodegradation, it must be excluded from further biomedical testing as it showed pathological effects on the host tissue following complete degradation.
镁合金是作为可吸收内固定材料的研究重点，因为它们提供足够的稳定性，使手术取出植入物成为不必要。新型可降解镁合金 ZEK100 通过与锌、稀土金属和锆合金化来提高稳定性和耐腐蚀性。由于在前一项体内研究中，植入物在 6 个月后仅降解到一定程度，因此进行了本研究，以在相同的动物模型中评估 9 和 12 个月时的长期降解行为和生物相容性。每个兔子的胫骨骨髓内都植入了一个植入物，共进行了 9 个月和 12 个月的检查。三条腿没有植入物作为阴性对照。在后续（临床检查、血清分析以及放射学和体内 micro-CT 研究）和死后（离体 micro-CT、组织学和植入物分析）进行了多次检查，以评估体内降解和生物相容性。结果表明，有利的体内降解行为不一定与良好的生物相容性相关。尽管 ZEK100 提供了非常高的初始稳定性和积极的生物降解性，但由于它在完全降解后对宿主组织产生了病理影响，因此必须排除在进一步的生物医学测试之外。
