Center for Biomaterials and Tissue Engineering, Universidad Politécnica de Valencia, 46022 Valencia, Spain.
Colloids Surf B Biointerfaces. 2010 Jun 1;77(2):181-90. doi: 10.1016/j.colsurfb.2010.01.021. Epub 2010 Feb 4.
Phase separation of PLLA/PS (50/50, w/w) solutions during a spin-casting process gives rise to well-defined nanotopographies of 14, 29 and 45 nm deep pits depending on the concentration of the solution. Their influence on the biological activity of fibronectin (FN) was investigated. FN adsorption was quantified by radiolabelling the protein. The amount of adsorbed FN was higher on the 14 nm deep pit nanotopography than on the other two surfaces. FN distribution between valleys and peaks was investigated by AFM combined with image analysis. FN tends to adsorb preferentially on the valleys of the nanotopography only for the 14 nm system and when adsorbed from solutions of concentration lower than 10 microg/ml. Higher concentration of the FN solution leads to evenly distribution of the protein throughout the surface; moreover, there is no difference in the distribution of the protein between valleys and peaks for the other two systems (29 and 45 nm) irrespective of the concentration of the FN solution. The biological activity of the adsorbed protein layer was assessed by investigating MC3T3 osteoblast-like cells adhesion, FN reorganisation and late matrix formation on the different substrates. Even if initial cell adhesion is excellent for every substrate, the size of the focal adhesion plaques increases as the size of the pits in the nanotopography does. This is correlated to FN reorganisation, which only takes places on the 29 and 45 nm deep pits surfaces, where enhanced late matrix production was also found.
在旋涂过程中，PLLA/PS（50/50，w/w）溶液的相分离会产生深度为 14、29 和 45nm 的规则纳米凹坑形貌，具体取决于溶液的浓度。研究了它们对纤维连接蛋白（FN）生物活性的影响。通过放射性标记蛋白质来定量 FN 的吸附。与其他两种表面相比，FN 在 14nm 深凹坑纳米形貌上的吸附量更高。通过 AFM 结合图像分析研究了 FN 在谷和峰之间的分布。FN 仅在 14nm 体系中且从浓度低于 10μg/ml 的溶液中吸附时，倾向于优先吸附在纳米形貌的谷上。FN 溶液浓度较高时，蛋白质会均匀分布在整个表面上；此外，对于其他两种体系（29 和 45nm），FN 溶液浓度无论如何，蛋白质在谷和峰之间的分布没有差异。通过研究不同基底上 MC3T3 成骨样细胞的黏附、FN 重组和晚期基质形成来评估吸附蛋白层的生物活性。即使每种基底的初始细胞黏附都很好，但随着纳米形貌中凹坑的尺寸增加，焦点黏附斑的大小也会增加。这与 FN 重组相关，FN 重组仅发生在 29 和 45nm 深凹坑表面，也发现了增强的晚期基质生成。
