Magnetic Flattening of Stem-Cell Spheroids Indicates a Size-Dependent Elastocapillary Transition

Francois Mazuel , Myriam Reffay , Vicard Du , Jean-Claude Bacri , Jean-Paul Rieu (1) , Claire Wilhelm

1 ILM - Institut Lumière Matière [Villeurbanne]

Cellular aggregates (spheroids) are widely used in biophysics and tissue engineering as model systems for biological tissues. In this Letter we propose novel methods for molding stem-cell spheroids, deforming them, and measuring their interfacial and elastic properties with a single method based on cell tagging with magnetic nanoparticles and application of a magnetic field gradient. Magnetic molding yields spheroids of unprecedented sizes (up to a few mm in diameter) and preserves tissue integrity. On subjecting these spheroids to magnetic flattening (over 150g), we observed a sizedependent elastocapillary transition with two modes of deformation: liquid-drop-like behavior for small spheroids, and elastic-sphere-like behavior for larger spheroids, followed by relaxation to a liquidlike drop.

Domaines: Chimie; Physique [physics]; Sciences de l'ingénieur [physics]

Francois Mazuel, Myriam Reffay, Vicard Du, Jean-Claude Bacri, Jean-Paul Rieu, et al.. Magnetic Flattening of Stem-Cell Spheroids Indicates a Size-Dependent Elastocapillary Transition. Physical Review Letters, 2015, 114, pp.098105. ⟨10.1103/PhysRevLett.114.098105⟩. ⟨hal-02307262⟩