Chen Xiyi, Su Yuan-Deng, Ajeti Visar, Chen Shean-Jen, Campagnola Paul J
Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, WI 53717, USA.
Cell Mol Bioeng. 2012 Sep;5(3):307-319. doi: 10.1007/s12195-012-0237-8.
Concentration gradients of ECM proteins play active roles in many areas of cell biology including wound healing and metastasis. They may also form the basis of tissue engineering scaffolds, as these can direct cell adhesion and migration and promote new matrix synthesis. To better understand cell-matrix interactions on attractive gradients, we have used multiphoton excited (MPE) photochemistry to fabricate covalently linked micro-structured gradients from fibronectin (FN). The gradient design is comprised of a parallel series of individual linear gradients with overall dimensions of approximately 800 × 800 m, where a linear dynamic range of nearly 10-fold in concentration was achieved. The adhesion dynamics of 3T3 fibroblasts were investigated, where the cell morphology and actin cytoskeleton became increasingly elongated and aligned with the direction of the gradient at increasing protein concentration. Moreover, the cell morphologies are distinct when adhered to regions of differing FN concentration but with similar topography. These results show that the fabrication approach allows investigating the roles of contact guidance and ECM cues on the cell-matrix interactions. We suggest this design overcomes some of the limitations with other fabrication methods, especially in terms of 3D patterning capabilities, and will serve as a new tool to study cell-matrix interactions.
细胞外基质（ECM）蛋白的浓度梯度在细胞生物学的许多领域发挥着积极作用，包括伤口愈合和转移。它们也可能构成组织工程支架的基础，因为这些支架可以引导细胞黏附和迁移，并促进新基质的合成。为了更好地理解细胞在有吸引力的梯度上与基质的相互作用，我们利用多光子激发（MPE）光化学技术，从纤连蛋白（FN）制备了共价连接的微结构梯度。梯度设计由一系列平行的单个线性梯度组成，总体尺寸约为800×800μm，其中浓度实现了近10倍的线性动态范围。研究了3T3成纤维细胞的黏附动力学，在蛋白质浓度增加时，细胞形态和肌动蛋白细胞骨架变得越来越细长，并与梯度方向对齐。此外，当细胞黏附在不同FN浓度但地形相似的区域时，细胞形态是不同的。这些结果表明，这种制备方法能够研究接触导向和ECM信号在细胞与基质相互作用中的作用。我们认为这种设计克服了其他制备方法的一些局限性，特别是在三维图案化能力方面，并将成为研究细胞与基质相互作用的新工具。
