Probing elasticity and adhesion of live cells by atomic force microscopy indentation
- 1.1k Downloads
Atomic force microscopy (AFM) indentation has become an important technique for quantifying the mechanical properties of live cells at nanoscale. However, determination of cell elasticity modulus from the force–displacement curves measured in the AFM indentations is not a trivial task. The present work shows that these force–displacement curves are affected by indenter-cell adhesion force, while the use of an appropriate indentation model may provide information on the cell elasticity and the work of adhesion of the cell membrane to the surface of the AFM probes. A recently proposed indentation model (Sirghi, Rossi in Appl Phys Lett 89:243118, 2006), which accounts for the effect of the adhesion force in nanoscale indentation, is applied to the AFM indentation experiments performed on live cells with pyramidal indenters. The model considers that the indentation force equilibrates the elastic force of the cell cytoskeleton and the adhesion force of the cell membrane. It is assumed that the indenter-cell contact area and the adhesion force decrease continuously during the unloading part of the indentation (peeling model). Force–displacement curves measured in indentation experiments performed with silicon nitride AFM probes with pyramidal tips on live cells (mouse fibroblast Balb/c3T3 clone A31-1-1) in physiological medium at 37°C agree well with the theoretical prediction and are used to determine the cell elasticity modulus and indenter-cell work of adhesion.
KeywordsCell mechanics Atomic force microscopy indentation Cell membrane adhesion
We are grateful to Mr. Takao Sasaki for SEM images of the AFM probes used in the experiments.
- A-Hassan E, Heinz WF, Antonik MD, D’Costa NP, Nageswaran S, Schoenenberger C-A, Hoh JH (1998) Relative microelastic mapping of living cells by atomic force microscopy. Biophys J 74:1564–1578Google Scholar
- Alcaraz J, Buscemi L, Grabulosa M, Trepat X, Fabry B, Farree R, Navajas D (2003) Microrheology of human lung epithelial cells measured by atomic force microscopy. Biophys J 84:2071–2079Google Scholar
- Andersen L K, Cortera SA, Justesen J, Duch M, Hansen O, Chevallier J, Foss M, Pedersen FS and, Besenbacher F (2005) Cell volume increase in murine MC3T3-E1 Pre-ostereoblasts attaching onto biocompatible tantalum observed by magnetic AC mode atomic force microscopy. Euro Cells Mater 10:61–69Google Scholar
- Israelachivili JN (1992) Intermolecular and surface forces, 2nd edn. Academic Press, LondonGoogle Scholar
- Jena BP (2002) Fusion pore in live cells. News Physiol Sci 17:219–222Google Scholar
- Rotsch C, Radmacher M (2000) Drug-induced changes of cytoskeletal structure and mechanics in fibroblasts: an atomic force microscopy study. Biophys J 78:520–535Google Scholar
- Radmacher M (2002) Measuring the elastic properties of living cells by the atomic force microscopy. In: Jena BP, Horber JK (eds) Methods in Cell Biology, vol 68. Academic Press, Elsevier, New York, Amsterdam, pp 67–90Google Scholar
- Schaus SS, Henderson ER (1997) Cell viability and probe-cell membrane interactions of XR1 glial cells imaged by atomic force microscopy. Biophys J 73:1205–1214Google Scholar
- Seifert U, Lipowsky R (1995) The structure and dynamics of membranes. In: Lipowsky R, Sackmann E (eds) Handbook of biological physics, vol 1. Elsevier, AmsterdamGoogle Scholar
- Zhu AP, Fang N, Chan-Park MB, Chan V (2006) Adhesion contact dynamics of 3T3 fibroblasts on poly (lactide-co-glycoide acid). Surf Modified Photochem Immobil Biomacromolec Biomater 27:2566–2576Google Scholar