Porter Alexandra E, Patel Nelesh, Skepper Jeremy N, Best Serena M, Bonfield William
Department of Materials Science and Metallurgy, Cambridge University, Pembroke Street, Cambridge CB2 3QZ, UK.
Biomaterials. 2004 Jul;25(16):3303-14. doi: 10.1016/j.biomaterials.2003.10.006.
Phase pure, sintered granules of hydroxyapatite (HA) and silicon-substituted hydroxyapatite (Si-HA) were implanted for 6 and 12 weeks in an ovine model. Samples containing the bone-implant interface were prepared for ultramicrotomy and transmission electron microscopy (TEM) using an anhydrous sample preparation procedure. The results demonstrate that the morphology of apatite deposits and the sequence of events at the interfaces of bone with pure HA and with Si-HA implants, were different. Organised collagen fibrils were first found at the bone/Si-HA interface after 6 weeks, whereas they were found only after 12 weeks around the pure HA implant. Many more nodular aggregates comprised of plate-like apatite crystallites were observed in the vicinity of Si-HA than around the pure HA after 12 weeks in vivo. These findings suggest that the incorporation of silicate ions into HA promotes processes of bone remodelling at the bone/HA interface. TEM observations suggested that the trabecular bone weaves over the Si-HA and that the collagen fibrils form a mechanical interlock with the Si-HA ceramic implants. High-resolution lattice imaging illustrated apatite crystallites contiguous with the Si-HA ceramic and revealed a direct relationship between the bone mineral and the Si-HA ceramic.
将羟基磷灰石（HA）和硅取代羟基磷灰石（Si-HA）的纯相烧结颗粒植入绵羊模型中6周和12周。使用无水样品制备程序制备包含骨-植入物界面的样品用于超薄切片术和透射电子显微镜（TEM）观察。结果表明，磷灰石沉积物的形态以及骨与纯HA和Si-HA植入物界面处的事件顺序是不同的。6周后在骨/Si-HA界面首次发现有组织的胶原纤维，而在纯HA植入物周围仅在12周后才发现。在体内植入12周后，在Si-HA附近观察到的由板状磷灰石微晶组成的结节状聚类比纯HA周围更多。这些发现表明，将硅酸根离子掺入HA中可促进骨/HA界面处的骨重塑过程。TEM观察表明，小梁骨覆盖在Si-HA上，并且胶原纤维与Si-HA陶瓷植入物形成机械互锁。高分辨率晶格成像显示磷灰石微晶与Si-HA陶瓷相邻，并揭示了骨矿物质与Si-HA陶瓷之间的直接关系。
