Zhu Xiaolong, Chen Jun, Scheideler Lutz, Altebaeumer Thomas, Geis-Gerstorfer Juergen, Kern Dieter
Section of Medical Materials and Technology, Department of Prosthodontics and Medical Materials, University of Tübingen, Tübingen, Germany.
Cells Tissues Organs. 2004;178(1):13-22. doi: 10.1159/000081089.
Osteoblast reactions to topographic structures of titanium play a key role in host tissue responses and the final osseointegration. Since it is difficult to fabricate micro- and nano-scale structures on titanium surfaces, little is known about the mechanism whereby the topography of titanium surfaces exerts its effects on cell behavior at the cellular level. In the present study, the titanium surface was structured in micron- and submicron-scale ranges by anodic oxidation in either 0.2 M H3PO4 or 0.03 M calcium glycerophosphate with 0.15 calcium acetate. The average dimensions of pores in the structured surface were about 0.5 and 2 microm in diameter, with roughness averaging at 0.2 and 0.4 microm, respectively. Enhanced attachment of cells (SaOS-2) was shown on micron- and submicron-scale structures. Initial cell reactions to different titanium surfaces, e.g. the development of the actin-containing structures, are determined by the different morphology of the surfaces. It is demonstrated that on either micron- or submicron-structured surfaces, many well-developed filopodia were observed to be primary adhesion structures in cell-substrate interactions, and some of them entered pores using their distinct tips or points along their length for initial attachment. Therefore, porous structures at either micro- or submicrometre scale supply positive guidance cues for anchorage-dependent cells to attach, leading to enhanced cell attachment. In contrast, the cells attached to a smooth titanium surface by focal contacts around their periphery as predominant adhesion structures, since repulsive signals from the environment led to retraction of the filopodia back to the cell bodies. These cells showed well-organized stress fibres, which exert tension across the cell body, resulting in flattened cells.
成骨细胞对钛的表面形貌结构的反应在宿主组织反应和最终的骨整合中起着关键作用。由于在钛表面制造微米和纳米尺度的结构很困难，关于钛表面形貌在细胞水平上对细胞行为产生影响的机制，人们所知甚少。在本研究中，通过在0.2 M磷酸（H3PO4）或含有0.15醋酸钙的0.03 M甘油磷酸钙中进行阳极氧化，在微米和亚微米尺度范围内构建钛表面结构。结构化表面的孔隙平均直径约为0.5微米和2微米，粗糙度平均分别为0.2微米和0.4微米。在微米和亚微米尺度结构上显示出细胞（SaOS-2）附着增强。细胞对不同钛表面的初始反应，例如含肌动蛋白结构的形成，由表面的不同形态决定。结果表明，在微米或亚微米结构表面上，许多发育良好的丝状伪足被观察到是细胞与基质相互作用中的主要粘附结构，其中一些丝状伪足利用其独特的尖端或沿其长度的点进入孔隙以进行初始附着。因此，微米或亚微米尺度的多孔结构为依赖锚定的细胞附着提供了积极的引导线索，导致细胞附着增强。相比之下，细胞通过其周边的粘着斑附着在光滑的钛表面上，作为主要的粘附结构，因为来自环境的排斥信号导致丝状伪足缩回细胞体。这些细胞显示出组织良好的应力纤维，其在细胞体上施加张力，导致细胞扁平。
