University Medical Center Rostock, Dept. of Cell Biology, Schillingallee 69, 18057 Rostock, Germany.
Leibniz-Institute for Plasma Science and Technology e.V. (INP), Felix-Hausdorff-Str. 2, 17489 Greifswald, Germany.
J Cell Sci. 2018 Jan 4;131(1):jcs207001. doi: 10.1242/jcs.207001.
The topographical and chemical surface features of biomaterials are sensed by the cells, affecting their physiology at the interface. When placed on titanium, we recently discovered osteoblasts attempted caveolae-mediated phagocytosis of the sharp-edged microstructures. This active, energy-consuming process resulted in decreased osteoblastic cell functions (e.g. secretion of extracellular matrix proteins). However, chemical modification with plasma polymerized allylamine (PPAAm) was able to amplify osteoblast adhesion and spreading, resulting in better implant osseointegration In the present study, we analyzed whether this plasma polymer nanocoating is able to attenuate the microtopography-induced changes of osteoblast physiology. On PPAAm, we found cells showed a higher cell interaction with the geometrical micropillars by 30 min, and a less distinct reduction in the mRNA expression of collagen type I, osteocalcin and fibronectin after 24 h of cell growth. Interestingly, the cells were more active and sensitive on PPAAm-coated micropillars, and react with a substantial Ca ion mobilization after stimulation with ATP. These results highlight that it is important for osteoblasts to establish cell surface contact for them to perform their functions.
生物材料的表面形貌和化学特征被细胞感知，从而影响细胞在界面处的生理学功能。最近我们发现，当将成骨细胞放置在钛上时，成骨细胞会尝试通过网格蛋白介导的胞吞作用来吞噬具有锋利边缘的微结构。这种主动的、耗能的过程导致成骨细胞功能下降（例如细胞外基质蛋白的分泌）。然而，通过等离子体聚合丙烯胺（PPAAm）进行化学修饰能够增强成骨细胞的黏附和扩展，从而实现更好的植入体骨整合。在本研究中，我们分析了这种等离子体聚合物纳米涂层是否能够减轻微形貌诱导的成骨细胞生理学变化。我们发现，在 PPAAm 上，细胞与几何微柱的相互作用在 30 分钟内就增强了，并且在细胞生长 24 小时后，Ⅰ型胶原、骨钙素和纤连蛋白的 mRNA 表达减少不明显。有趣的是，细胞在涂有 PPAAm 的微柱上更加活跃和敏感，并且在用 ATP 刺激后会发生大量钙离子动员。这些结果强调了细胞表面接触对于成骨细胞发挥功能的重要性。
