RESUMEN
The use of force spectroscopy to study the adhesion of living fibroblasts to their culture substrate was investigated. Both primary fibroblasts (PEMF) and a continuous cell line (3T3) were studied on quartz surfaces. Using a fibronectin-coated AFM cantilever, it was possible to detach a large proportion of the 3T3 cells from the quartz surfaces. Their adhesion to the quartz surface and the effects of topography on this adhesion could be quantified. Three parameters characteristic of the adhesion were measured: the maximum force of detachment, the work of adhesion, and the distance of detachment. Few PEMF cells were detached under the same experimental conditions. The potential and limitations of this method in measuring cell/surface interactions for adherent cells are discussed.
Asunto(s)
Adhesión Celular , Microscopía de Fuerza Atómica/métodos , Células 3T3 , Animales , Proliferación Celular , Fibronectinas/química , Ratones , Propiedades de SuperficieRESUMEN
Force spectroscopy has been used to measure the adhesion of Saos-2 cells to a glass surface at different phases of the cell cycle. The cells were synchronized in three phases of the cell cycle: G(1), S, and G(2)M. Cells in these phases were compared with unsynchronized and native mitotic cells. Individual cells were attached to an atomic force microscope cantilever, brought into brief contact with the glass surface, and then pulled off again. The force-distance curves obtained allowed the work and maximum force of detachment as well as the number, amplitude, and position of discrete unbinding steps to be determined. A statistical analysis of the data showed that the number of binding proteins or protein complexes present at the cell surface and their binding properties remain similar throughout the cell cycle. This, despite the huge changes in cell morphology and adhesion that occur as the cells enter mitosis. These changes are rather associated with the changes in cytoskeletal organization, which can be quantified by force spectroscopy as changes in cell stiffness.