title: Magnetic flattening of stem-cell spheroids indicates a size-dependent elastocapillary transition.
abstract: 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 size-dependent 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.
authors: Laboratoire Matière et Systèmes Complexes, UMR 7057, CNRS, Université Paris Diderot, 75013 Paris, France.
authors: Francois
authors: F
authors: Mazuel
authors: Laboratoire Matière et Systèmes Complexes, UMR 7057, CNRS, Université Paris Diderot, 75013 Paris, France.
authors: Myriam
authors: M
authors: Reffay
authors: Laboratoire Matière et Systèmes Complexes, UMR 7057, CNRS, Université Paris Diderot, 75013 Paris, France.
authors: Vicard
authors: V
authors: Du
authors: Laboratoire Matière et Systèmes Complexes, UMR 7057, CNRS, Université Paris Diderot, 75013 Paris, France.
authors: Jean-Claude
authors: JC
authors: Bacri
authors: Institut Lumière Matière, UMR 5306, Université Lyon 1-CNRS, Université de Lyon, 69622 Villeurbanne cedex, France.
authors: Jean-Paul
authors: JP
authors: Rieu
authors: Laboratoire Matière et Systèmes Complexes, UMR 7057, CNRS, Université Paris Diderot, 75013 Paris, France.
authors: Claire
authors: C
authors: Wilhelm
mesh_terms: D002449:Cell Aggregation; D002450:Cell Communication; D006801:Humans; D008280:Magnetics / Q000379:methods*; D059630:Mesenchymal Stem Cells / Q000166:cytology*; D018613:Microscopy, Confocal / Q000379:methods; D008954:Models, Biological; D039904:Pluripotent Stem Cells / Q000166:cytology*; D018874:Spheroids, Cellular / Q000166:cytology*