Investigating cell‐substrate and cell–cell interactions by means of single‐cell‐probe force spectroscopy

ABSTRACT Cell adhesion forces are typically a mixture of specific and nonspecific cell‐substrate and cell–cell interactions. In order to resolve these phenomena, Atomic Force Microscopy appears as a powerful device which can measure cell parameters by means of manipulation of single cells. This method, commonly known as cell‐probe force spectroscopy, allows us to control the force applied, the area of interest, the approach/retracting speed, the force rate, and the time of interaction. Here, we developed a novel approach for in situ cantilever cell capturing and measurement of specific cell interactions. In particular, we present a new setup consisting of two different half‐surfaces coated either with recrystallized SbpA bacterial cell surface layer proteins (S‐layers) or integrin binding Fibronectin, on which MCF‐7 breast cancer cells are incubated. The presence of a clear physical boundary between both surfaces benefits for a quick detection of the region under analysis. Thus, quantitative results about SbpA‐cell and Fibronectin‐cell adhesion forces as a function of the contact time are described. Additionally, the importance of the cell spreading in cell–cell interactions has been studied for surfaces coated with two different Fibronectin concentrations: 20 μg/mL (FN20) and 100 μg/mL (FN100), which impact the number of substrate receptors. Microsc. Res. Tech. 80:124–130, 2017. © 2016 Wiley Periodicals, Inc.