State-key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University, Xi'an 710049, China.
Department of Genetics and Molecular Biology, College of Medicine, Xi'an Jiaotong University, Xi'an 710061, China.
Colloids Surf B Biointerfaces. 2013 Nov 1;111:232-41. doi: 10.1016/j.colsurfb.2013.06.007. Epub 2013 Jun 15.
Nano- and ultrafine-grained β-Ti layers were fabricated on Ti-25Nb-3Mo-3Zr-2Sn alloy by surface mechanical attrition treatment (SMAT). After being ground and polished, the two layers exhibited the same chemical composition, similar surface roughness and topography features to the coarse-grained surface, however, higher hardness values were exhibited on the ultrafine- and nano-grained surfaces, especially on nano-grained surface compared to coarse-grained surface. Hydrophilicity test, evaluated by measuring water contact angles, showed that the nano-grained surface was much more hydrophilic than the ultrafine- and coarse-grained surfaces. The adsorption of total protein and anchoring proteins such as vitronectin and fibronectin on the different surfaces from DMEM medium containing 10% fetal bovine serum was also examined. Employing hFOB1.19 cells, the behaviors of osteoblasts on the three kinds of grain-scaled surfaces, including adhesion, proliferation and differentiation, were evaluated by examining the morphology, the number of adherent cells, actin cytoskeleton reorganization, vinculin signals, expressions of steogenesis-related genes, alkaline phosphatase activity, contents of intracellular specific proteins and collagen type I, extracellular collagen secretion as well as matrix mineralization. The significant enhancements of osteoblast adhesion, proliferation, maturation and mineralization are exhibited on the nano-grained surface, while little improvements are found on the ultrafine-grained surface compared to the conventional coarse-grained surface. The differences in the cellular response to the three kinds of grain-scaled surfaces are related to grain size and degree of hydrophilicity. The improved cell functions together with mechanical properties make SMAT-processed nanograined β-Ti a promising biomaterial for surgical implants.
通过表面机械研磨处理（SMAT）在 Ti-25Nb-3Mo-3Zr-2Sn 合金上制备了纳米和超细晶粒β-Ti 层。经过研磨和抛光后，这两层具有与粗晶粒表面相同的化学成分、相似的表面粗糙度和形貌特征，但在超细和纳米晶粒表面表现出更高的硬度值，尤其是纳米晶粒表面比粗晶粒表面更高。通过测量水接触角评估的亲水性测试表明，纳米晶粒表面比超细和粗晶粒表面更亲水。还研究了不同表面从含有 10%胎牛血清的 DMEM 培养基中吸附总蛋白和锚定蛋白，如纤连蛋白和玻连蛋白。使用 hFOB1.19 细胞，通过检查形态、贴壁细胞数量、肌动蛋白细胞骨架重组、连接蛋白信号、成骨相关基因表达、碱性磷酸酶活性、细胞内特定蛋白质和 I 型胶原含量、细胞外胶原分泌以及基质矿化等方面，评估了成骨细胞在这三种晶粒尺度表面上的黏附、增殖和分化行为。与传统的粗晶粒表面相比，在纳米晶粒表面上表现出显著增强的成骨细胞黏附、增殖、成熟和矿化，而在超细晶粒表面上则发现了很少的改善。细胞对这三种晶粒尺度表面的反应差异与晶粒尺寸和亲水性程度有关。改善的细胞功能和机械性能使经过 SMAT 处理的纳米晶粒β-Ti 成为一种有前途的外科植入物生物材料。
