Gugutkov Dencho, González-García Cristina, Rodríguez Hernández José Carlos, Altankov George, Salmerón-Sánchez Manuel
Institut de Bioenginyeria de Catalunya (IBEC), 08028 Barcelona, Spain.
Langmuir. 2009 Sep 15;25(18):10893-900. doi: 10.1021/la9012203.
Fibronectin (FN) fibrillogenesis is a cell-mediated process involving integrin activation that results in conformational changes of FN molecules and the organization of actin cytoskeleton. A similar process can be induced by some chemistries in the absence of cells, e.g., poly(ethyl acrylate) (PEA), which enhance FN-FN interactions leading to the formation of a biologically active network. Atomic force microscopy images of single FN molecules, at the early stages of adsorption on plane PEA, allow one to rationalize the process. Further, the role of the spatial organization of the FN network on the cellular response is investigated through its adsorption on electrospun fibers. Randomly oriented and aligned PEA fibers were prepared to mimic the three-dimensional organization of the extracellular matrix. The formation of the FN network on the PEA fibers but not on the supporting coverglass was confirmed. Fibroblasts aligned with oriented fibers, displayed extended morphology, developed linearly organized focal adhesion complexes, and matured actin filaments. Conversely, on random PEA fibers, cells acquired polygonal morphology with altered actin cytoskeleton but well-developed focal adhesions. Late FN matrix formation was also influenced: spatially organized FN matrix fibrils along the oriented PEA fibers and an altered arrangement on random ones.
纤连蛋白（FN）原纤维形成是一个细胞介导的过程，涉及整合素激活，导致FN分子的构象变化和肌动蛋白细胞骨架的组织。在没有细胞的情况下，一些化学物质，如聚丙烯酸乙酯（PEA），也可以诱导类似的过程，其增强了FN-FN相互作用，导致形成生物活性网络。在平面PEA上吸附早期的单个FN分子的原子力显微镜图像，使人们能够合理地解释这一过程。此外，通过将FN网络吸附在电纺纤维上，研究了FN网络的空间组织对细胞反应的作用。制备了随机取向和排列的PEA纤维，以模拟细胞外基质的三维组织。证实了在PEA纤维上而不是在支撑盖玻片上形成了FN网络。与取向纤维对齐的成纤维细胞呈现出伸长的形态，形成线性组织的粘着斑复合物，并使肌动蛋白丝成熟。相反，在随机的PEA纤维上，细胞获得多边形形态，肌动蛋白细胞骨架改变，但粘着斑发育良好。晚期FN基质形成也受到影响：沿取向PEA纤维形成空间组织的FN基质原纤维，而在随机纤维上排列改变。
