Department of Materials Science, University of Erlangen-Nuremberg, Germany.
Acta Biomater. 2012 Jul;8(7):2639-47. doi: 10.1016/j.actbio.2012.03.040. Epub 2012 Mar 30.
By electrochemical anodization, highly ordered nanotubular TiO(2) structures were formed on titanium surfaces with diameters of 15 and 100 nm. In previous work we showed that 15 nm tubes strongly enhanced adhesion and vitality of many cell types, whereas on 100 nm diameter tubes the induction of apoptosis was observed. In the present work we produce mixed (15 nm contrasted with 100 nm) nanotube microstructures that combine highly defined micro- and nanostructures using a photolithographic approach to achieve a direct comparison of adhesion and spreading of mesenchymal stem cells on different diameter nanotubes present on a single surface. On these coupled different nanoscale surfaces mesenchymal stem cell adhesion is initially favoured on 15 nm tube areas but, with time, a gradient in cell number and shape to the "unfavourable" regions of the substrate (100 nm tubes) can be observed. This can be explained by cells on the "favourable" 15 nm regions that strongly produce and shed extracellular matrix onto the "unfavourable" locations. These findings contribute to the design of cell guiding surfaces, but also demonstrate the need for a long-range defined homogeneous order when studying cell behaviour on nanostructured surfaces.
通过电化学阳极氧化，钛表面形成了直径为 15nm 和 100nm 的高度有序的纳米管状 TiO2 结构。在之前的研究中，我们发现 15nm 管强烈促进了许多细胞类型的黏附和活力，而在 100nm 直径的管上观察到了细胞凋亡的诱导。在本工作中，我们采用光刻技术制备了混合（15nm 对比 100nm）纳米管微结构，将高度定义的微纳结构结合在一起，以实现对单个表面上不同直径纳米管上间充质干细胞黏附和铺展的直接比较。在这些耦合的不同纳米尺度表面上，间充质干细胞的黏附最初有利于 15nm 管区域，但随着时间的推移，可以观察到细胞数量和形状向基底（100nm 管）的“不利”区域的梯度变化。这可以通过在“有利”的 15nm 区域中强烈产生和释放细胞外基质到“不利”位置的细胞来解释。这些发现有助于设计细胞导向表面，但也证明了在研究纳米结构表面上细胞行为时需要具有长程定义的均匀有序性。
