State Key Laboratory of Metal Matrix Composites, School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China.
J Biomed Mater Res A. 2011 Dec 15;99(4):666-75. doi: 10.1002/jbm.a.33239. Epub 2011 Oct 3.
This study investigated the surface characteristics and in vitro cytocompatibility of hierarchical textured titanium surfaces with nanograins and microroughness, produced by surface mechanical attrition treatment (SMAT). The surface characteristics were evaluated by scanning electron microscopy, X-ray diffraction, transmission electron microscopy, contact angle, and surface energy measurements. The in vitro cytocompatibility of the SMAT processed surfaces (hereafter Ti-SMAT surfaces) were assessed in terms of cellular attachment, morphology, viability, alkaline phosphatase (ALP) activity, and mRNA gene expression. Two other titanium surfaces were compared: well-polished Ti6Al4V surfaces (hereafter Ti-polish surfaces) and thermally sprayed rough surfaces (hereafter Ti-spray surfaces). The Ti-SMAT surfaces showed a higher hydrophilicity and increased surface energy compared with the Ti-polish and Ti-spray surfaces. Consequently, these Ti-SMAT surfaces demonstrated enhancement of cell attachment, spreading, viability, and ALP activity. Reverse transcriptase polymerase chain reaction (RT-PCR) analysis showed significantly higher ALP activity and stronger expression of mRNA levels of key osteoblast genes in cells grown on the Ti-SMAT surfaces than the other two surfaces. These results reveal a synergic role played by nanostructure and microtopography in osteoblastic functions and demonstrate the more promising cytocompatibility of the hierarchical textured surfaces. It is suggested that the SMAT process may provide a novel method of surface modification to the currently available metallic biomaterials.
本研究探讨了通过表面机械研磨处理（SMAT）制备的具有纳米晶粒和微粗糙度的分级纹理钛表面的表面特性和体外细胞相容性。通过扫描电子显微镜、X 射线衍射、透射电子显微镜、接触角和表面能测量来评估表面特性。通过细胞附着、形态、活力、碱性磷酸酶（ALP）活性和 mRNA 基因表达来评估 SMAT 处理表面（以下简称 Ti-SMAT 表面）的体外细胞相容性。还比较了另外两种钛表面：经过精抛光的 Ti6Al4V 表面（以下简称 Ti-polish 表面）和热喷涂粗糙表面（以下简称 Ti-spray 表面）。与 Ti-polish 和 Ti-spray 表面相比，Ti-SMAT 表面表现出更高的亲水性和更高的表面能。因此，这些 Ti-SMAT 表面表现出增强的细胞附着、铺展、活力和 ALP 活性。逆转录聚合酶链反应（RT-PCR）分析显示，在 Ti-SMAT 表面上生长的细胞中，ALP 活性和关键成骨基因的 mRNA 水平表达明显更高。这些结果揭示了纳米结构和微形貌在成骨细胞功能中的协同作用，并证明了分级纹理表面更有前途的细胞相容性。建议 SMAT 工艺可能为现有的金属生物材料提供一种新的表面改性方法。
