Radboud University Nijmegen Medical Centre, Department of Biomaterials, Nijmegen, The Netherlands.
Biomaterials. 2010 Oct;31(30):7758-65. doi: 10.1016/j.biomaterials.2010.06.050.
Osteoblasts respond to mechanical stimulation by changing morphology, gene expression and matrix mineralization. Introducing surface topography on biomaterials, independently of mechanical loading, has been reported to give similar effects. In the current study, using a nanotextured surface, and mechanical loading, we aimed to develop a multi-factorial model in which both parameters interact. Mechanical stimulation to osteoblast-like cells was applied by longitudinal stretch in parallel direction to the nanotexture (300 nm wide and 60 nm deep grooves), with frequency of 1 Hz and stretch magnitude varying from 1% to 8%. Scanning electron microscopy showed that osteoblast-like cells subjected to mechanical loading oriented perpendicularly to the stretch direction. When cultured on nanotextured surfaces, cells aligned parallel to the texture. However, the parallel cell direction to the nanotextured surface was lost and turned to perpendicular when parallel stretch to the nanotexture, greater than 3% was applied to the cells. This phenomenon could not be achieved when a texture with micro-sized dimensions was used. Moreover, a significant synergistic effect on upregulation of fibronectin and Cfba was observed when dual stimulation was used. These findings can lead to a development of new biomimetic materials that can guide morphogenesis in tissue repair and bone remodeling.
成骨细胞对外界机械刺激的响应表现为形态改变、基因表达和基质矿化。有研究报道，在不施加机械载荷的情况下，通过在生物材料表面引入微观形貌结构，也可以产生类似的效果。在本研究中，我们采用纳米纹理表面和机械加载两种方式，旨在开发一种多因素模型，使两种参数相互作用。采用平行于纳米纹理（宽度 300nm，深度 60nm 的沟槽）方向的纵向拉伸对成骨样细胞进行机械刺激，频率为 1Hz，拉伸幅度为 1%至 8%。扫描电子显微镜显示，接受机械加载的成骨样细胞垂直于拉伸方向排列。当在纳米纹理表面培养时，细胞沿纹理平行排列。然而，当对细胞施加大于 3%的平行于纳米纹理的拉伸时，细胞会失去平行于纳米纹理的方向，并转向垂直方向。当使用具有微米级尺寸的纹理时，无法实现这种现象。此外，当采用双重刺激时，观察到纤维连接蛋白和 C-fos 结合蛋白 A 的上调有显著的协同作用。这些发现可以为新型仿生材料的开发提供依据，从而引导组织修复和骨重塑过程中的形态发生。
