Neuro-Physique Cellulaire, Université Paris Descartes, UFR Biomédicale, Paris, France.
Biomaterials. 2010 May;31(14):3762-71. doi: 10.1016/j.biomaterials.2010.01.099. Epub 2010 Feb 10.
Recent results indicate that, in addition to chemical, spatial and mechanical cues, substrate physical cues such as gradients in surface energy may also impact cell functions, such as neuronal differentiation of PC12 cells. However, it remains to be determined what surface effect is the most critical in triggering PC12 cell differentiation. Here we show that, beyond continuously probing the surface energy landscape of their environment, PC12 cells are highly sensitive to nanoscale chemical heterogeneities. Self-assembled monolayers of alkylsiloxanes on glass were used as a culture substrate. By changing the structure, ordering and chemical nature of the monolayer, the surface energy distribution is altered. While both well-ordered CH(3) terminated substrates and bare glass (OH terminated) substrates did not favor PC12 cell adhesion, PC12 cells seeded on highly disordered CH(3)/OH substrates underwent enhanced adhesion and prompt neuritogenesis by 48 h of culture, without nerve growth factor treatment. These data illustrate that surface free-energy gradients, generated by nanoscale chemical heterogeneities, are critical to biological processes such as nerve regeneration on biomaterials.
最近的研究结果表明，除了化学、空间和机械线索外，基底物理线索，如表面能的梯度，也可能影响细胞功能，如 PC12 细胞的神经元分化。然而，目前尚不清楚在触发 PC12 细胞分化方面，哪种表面效应最重要。在这里，我们发现，PC12 细胞不仅在不断探测其环境的表面能景观，而且对纳米级化学不均匀性高度敏感。玻璃上的烷基硅氧烷自组装单层被用作培养基底。通过改变单层的结构、有序性和化学性质，改变了表面能分布。虽然有序的 CH(3)末端基底和裸玻璃（OH 末端）基底都不利于 PC12 细胞的黏附，但在高度无序的 CH(3)/OH 基底上接种的 PC12 细胞在没有神经生长因子处理的情况下，在培养 48 小时后经历了增强的黏附和迅速的神经突形成。这些数据表明，由纳米级化学不均匀性产生的表面自由能梯度，对于生物材料上的神经再生等生物过程至关重要。
