School of Biomedical Engineering and Sciences, Virginia Tech, Blacksburg, VA, USA.
Acta Biomater. 2013 Jul;9(7):7169-77. doi: 10.1016/j.actbio.2013.03.042. Epub 2013 Apr 6.
In the body, cells dynamically respond to chemical and mechanical cues from the extracellular matrix (ECM), yet precise mechanisms by which biophysical parameters (stiffness, topography and alignment) affect cell behavior remain unclear. Here, highly aligned and suspended multilayer polystyrene (PS) nanofiber scaffolds are used to study biophysical influences on focal adhesion complex (FAC) arrangement and associated migration behavior of mouse C2C12 cells arranged in specific shapes: spindle, parallel and polygonal. Furthermore, the role of cytoskeletal-altering drugs including blebbistatin, nocodazole and cytochalasin-D on FAC formation and migratory behavior is investigated. For the first time, this work reports that cells on suspended fiber networks, including cells with administered drugs, elongated along the fiber axes and developed longer (∼ 4×) and more concentrated FAC clusters compared to cells on flat PS control substrates. Additionally, substrate designs which topographically restrict sites of cell attachment and align adhesions were found to promote higher migration speeds (spindle: 52μmh(-1), parallel: 39μmh(-1), polygonal: 25μmh(-1), flat: 32μmh(-1)). This work demonstrates that suspended fiber topography-induced concentration of FACs along fiber axes generates increased migration potential as opposed to flat surfaces, which diffuse and randomly orient adhesions.
在体内，细胞会对细胞外基质（ECM）中的化学和机械线索做出动态响应，但生物物理参数（刚度、形貌和取向）如何影响细胞行为的确切机制仍不清楚。在这里，我们使用高度取向和悬空的多层聚苯乙烯（PS）纳米纤维支架来研究生物物理因素对粘着斑复合物（FAC）排列的影响，以及特定形状排列的小鼠 C2C12 细胞（纺锤形、平行和多边形）的相关迁移行为。此外，还研究了包括 blebbistatin、nocodazole 和 cytochalasin-D 在内的改变细胞骨架的药物对 FAC 形成和迁移行为的作用。这是首次报道，悬空纤维网络上的细胞（包括施用药物的细胞）会沿着纤维轴伸长，并形成更长（∼4 倍）、更集中的 FAC 簇，而不是在 PS 对照基底上。此外，发现限制细胞附着部位和定向黏附的基底形貌设计可以促进更高的迁移速度（纺锤形：52μmh(-1)，平行：39μmh(-1)，多边形：25μmh(-1)，平面：32μmh(-1)）。这项工作表明，悬空纤维形貌诱导的 FAC 沿着纤维轴的集中产生了更高的迁移潜力，而不是在平面上扩散和随机定向黏附。
