Biological activity of the substrate-induced fibronectin network: Insight into the third dimension through electrospun fibers

[EN] 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, oil 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,AFM was performed tinder the technical guidance of the Microscopy Service at the Universidad Politecnica de Valencia, whose advice is greatly appreciated. The support of the Spanish Ministry of Science through project MAT200608120 (including the FEDER financial support) is kindly acknowledged. This work has been partly financed through 'convenio de colaboracion entre el Instituto de Salud Carlos III, la Conselleria de Sanidad de la Generalitat Valenciana y la Fundacion de la Comunidad Valenciana Centro de Investigacion Principe Felipe para la investigacion basica y traslacional en medicina regenerativa'.Gugutkov, D.; González-García, C.; Rodríguez Hernández, JC.; Altankov, G.; Salmerón Sánchez, M. (2009). Biological activity of the substrate-induced fibronectin network: Insight into the third dimension through electrospun fibers. Langmuir. 25(18):10893-10900. https://doi.org/10.1021/la90122031089310900251