Department of Chemical and Biochemical Engineering, Faculty of Engineering, The University of Western Ontario, London, Ontario, Canada.
Biomaterials. 2013 Oct;34(30):7215-26. doi: 10.1016/j.biomaterials.2013.06.014. Epub 2013 Jul 2.
The behavior of bone cells is influenced by the surface chemistry and topography of implants and scaffolds. Our purpose was to investigate how the topography of biomimetic hydroxyapatite (HA) coatings influences the attachment and differentiation of osteoblasts, and the resorptive activity of osteoclasts. Using strategies reported previously, we directly controlled the surface topography of HA coatings on polycaprolactone discs. Osteoblasts and osteoclasts were incubated on HA coatings having distinct isotropic topographies with submicrometer and micro-scale features. Osteoblast attachment and differentiation were greater on more complex, micro-rough HA surfaces (Ra ~2 μm) than on smoother topographies (Ra ~1 μm). In contrast, activity of the osteoclast marker tartrate-resistant acid phosphatase was greater on smoother than on micro-rough surfaces. Furthermore, scanning electron microscopy revealed the presence of resorption lacunae exclusively on smoother HA coatings. Inhibition of resorption on micro-rough surfaces was associated with disruption of filamentous actin sealing zones. In conclusion, HA coatings can be prepared with distinct topographies, which differentially regulate responses of osteoblasts, as well as osteoclastic activity and hence susceptibility to resorption. Thus, it may be possible to design HA coatings that induce optimal rates of bone formation and degradation specifically tailored for different applications in orthopedics and dentistry.
骨细胞的行为受植入物和支架表面化学性质和形貌的影响。我们的目的是研究仿生羟基磷灰石（HA）涂层的形貌如何影响成骨细胞的附着和分化，以及破骨细胞的吸收活性。我们使用先前报道的策略，直接控制聚己内酯盘上 HA 涂层的表面形貌。将成骨细胞和破骨细胞孵育在具有亚微米和微米特征的各向同性形貌的 HA 涂层上。与更光滑的形貌（Ra1μm）相比，更复杂的微粗糙 HA 表面（Ra2μm）上的成骨细胞附着和分化更大。相比之下，破骨细胞标志物抗酒石酸酸性磷酸酶的活性在更光滑的表面上大于微粗糙表面。此外，扫描电子显微镜显示仅在更光滑的 HA 涂层上存在吸收陷窝。在微粗糙表面上抑制吸收与丝状肌动蛋白密封区的破坏有关。总之，HA 涂层可以具有不同的形貌，这些形貌可以差异调节成骨细胞以及破骨细胞活性和吸收敏感性的反应。因此，有可能设计出专门针对矫形和牙科中不同应用的诱导最佳骨形成和降解速率的 HA 涂层。
