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.

Single-Cell Probe Force Studies to Identify Sox2 Overexpression-Promoted Cell Adhesion in MCF7 Breast Cancer Cells

“…Thus, cells are used to probe the interaction with either surfaces or other cells, permitting force-, position-, and time-resolved adhesion measurements [19,20]. Recently, we have successfully demonstrated an experimental approach to prepare cell samples for such measurements utilizing bacterial surface layer protein coatings, known by their high efficiency as anti-fouling coatings [21][22][23], in a feasible, easy-to-handle, one-step manner [24].…”

Novel biodegradable and non-fouling systems for controlled-release based on poly(ε-caprolactone)/Quercetin blends and biomimetic bacterial S-layer coatings

“…The presence of the SbpA S-layer does not only provide the PCL/ Q blends with an effective release-controlling membrane but also endows these lms with anti-fouling properties, known the good non-fouling activity of such type of coatings. 12,13 Continuing with the methodology explained in the previous section, HUVEC cells were seeded on different PCL/Q ratios which had previously been employed for the recrystallization of SbpA bacterial proteins. Again, samples were kept for 24 hours under cell growth promoting conditions and the cell area was measured as shown in Fig.…”

“…S-Layers are found in the outermost envelope of prokaryotes, and represent not only the simplest biological membrane but also a highly efficient protective membrane with proven anti-fouling activity. 12,13 From the bioengineering point of view, it is highly interesting that isolated S-layer protein sub-units have the ability to self-assemble, through the so-called recrystallization process, on a broad number of organic and inorganic supports. 14,15 This is the case of SbpA from Lysinibacillus sphaericus CCM2177, which presents a square (p4) lattice symmetry, a system that has quite extensively been characterized in literature so far.…”

A beginner's guide to atomic force microscopy probing for cell mechanics

“…In the case of tip-less cantilevers, they have been specially used when probing loosely attached spherical objects, such as nonadherent cells or isolated cell nuclei (Cartagena-Rivera, Logue, Waterman, & Chadwick, 2016;Chaudhuri, Parekh, Lam, & Fletcher, 2009;Lee et al, 2015;Stewart et al, 2013). In addition, tip-less cantilevers are a good substrate to attach living cells, which are then used as biological probes to measure adhesion strength of cell-cell interactions (Benoit & Selhuber-Unkel, 2011;Moreno-Cencerrado et al, 2016).…”