title: A general approach for the microrheology of cancer cells by atomic force microscopy.
abstract: The determination of the viscoelastic properties of cells by atomic force microscopy (AFM) is mainly realized by looking at the relaxation of the force when a constant position of the AFM head is maintained or at the evolution of the indentation when a constant force is maintained. In both cases the analysis rests on the hypothesis that the motion of the probe before the relaxation step is realized in a time which is much smaller than the characteristic relaxation time of the material. In this paper we carry out a more general analysis of the probe motion which contains both the indentation and relaxation steps, allowing a better determination of the rheological parameters. This analysis contains a correction of the Hertz model for large indentation and also the correction due to the finite thickness of the biological material; it can be applied to determine the parameters representing any kind of linear viscoelastic model. This approach is then used to model the rheological behavior of one kind of cancer cell called Hep-G2. For this kind of cell, a power law model does not well describe the low and high frequency modulus contrary to a generalized Maxwell model.
authors.affiliation: Laboratoire de Physique de la Matière Condensée (LPMC), CNRS UMR 7336, Université de Nice-Sophia Antipolis, Parc Valrose, 06108 Nice Cedex 2, France.
authors.forename: Biran
authors.initials: B
authors.lastname: Wang
authors.forename: Pascal
authors.initials: P
authors.lastname: Lançon
authors.forename: Céline
authors.initials: C
authors.lastname: Bienvenu
authors.forename: Pierre
authors.initials: P
authors.lastname: Vierling
authors.forename: Christophe
authors.initials: C
authors.lastname: Di Giorgio
authors.forename: Georges
authors.initials: G
authors.lastname: Bossis
mesh_terms: D045744:Cell Line, Tumor; D004548:Elasticity; D056945:Hep G2 Cells; D006801:Humans; D008113:Liver Neoplasms; D018625:Microscopy, Atomic Force; D008954:Models, Biological; D012212:Rheology / Q000379:methods*; D013314:Stress, Mechanical; D014783:Viscosity