Ni Siyu, Sun Linlin, Ercan Batur, Liu Luting, Ziemer Katherine, Webster Thomas J
College of Chemistry, Chemical Engineering and Biotechnology, Donghua University, Shanghai, 201620, China; Department of Chemical Engineering, College of Engineering, Northeastern University, Boston, Massachusetts.
J Biomed Mater Res B Appl Biomater. 2014 Aug;102(6):1297-303. doi: 10.1002/jbm.b.33127. Epub 2014 Mar 8.
In this study, 316L stainless steel with tunable nanometer pit sizes (0, 25, 50, and 60 nm) were fabricated by an anodization procedure in an ethylene glycol electrolyte solution containing 5 vol % perchloric acid. The surface morphology and elemental composition of the 316L stainless steel were characterized by scanning electron microscopy (SEM), atomic force microscopy (AFM), and X-ray photoelectron spectroscopy (XPS). The nano-pit arrays on all of the 316L stainless steel samples were in a regular arrangement. The surface properties of the 316L stainless steel nano-pit surface showed improved wettability properties as compared with the untreated 316L stainless steel, as demonstrated by the lower contact angles which dropped from 83.0° to 28.6 to 45.4°. The anodized 316L stainless steel surfaces with 50 nm and 60 nm diameter pits were also more rough at the nanoscale. According to MTT assays, compared with unanodized (that is, nano-smooth) surfaces, the 50 and 60 nm diameter nano-pit surfaces dramatically enhanced initial human dermal fibroblast attachment and growth for up to 3 days in culture. Mechanistically, this study also provided the first evidence of greater select protein adsorption (specifically, vitronectin and fibronectin which have been shown to enhance fibroblast adhesion) on the anodized 316L stainless steel compared with unanodized stainless steel. Such nano-pit surfaces can be designed to support fibroblast growth and, thus, improve the use of 316L stainless steel for various implant applications (such as for enhanced skin healing for amputee devices and for percutaneous implants).
在本研究中，通过在含有5体积%高氯酸的乙二醇电解液中进行阳极氧化工艺，制备了具有可调纳米坑尺寸（0、25、50和60纳米）的316L不锈钢。采用扫描电子显微镜（SEM）、原子力显微镜（AFM）和X射线光电子能谱（XPS）对316L不锈钢的表面形貌和元素组成进行了表征。所有316L不锈钢样品上的纳米坑阵列排列规则。与未处理的316L不锈钢相比，316L不锈钢纳米坑表面的表面性能表现出改善的润湿性，较低的接触角从83.0°降至28.6°至45.4°证明了这一点。直径为50纳米和60纳米的阳极氧化316L不锈钢表面在纳米尺度上也更粗糙。根据MTT分析，与未阳极氧化（即纳米光滑）表面相比，直径为50和60纳米的纳米坑表面在培养长达3天的时间里显著增强了人真皮成纤维细胞的初始附着和生长。从机制上讲，本研究还首次证明，与未阳极氧化的不锈钢相比，阳极氧化的316L不锈钢上有更多的选择性蛋白质吸附（特别是已被证明能增强成纤维细胞粘附的玻连蛋白和纤连蛋白）。这种纳米坑表面可以设计成支持成纤维细胞生长，从而改善316L不锈钢在各种植入应用中的使用（例如用于增强截肢设备的皮肤愈合和经皮植入物）。
