Structure and dynamics of multicellular assemblies measured by coherent light scattering

Benjamin Brunel (1) , Carles Blanch (2) , Aurélien Gourrier (1) , Vanni Petrolli (1) , Antoine Delon (1) , Jean-François Joanny (3, 2) , Rémi Carminati (4) , Romain Pierrat (4) , Giovanni Cappello (1)

1 LIPhy - Laboratoire Interdisciplinaire de Physique [Saint Martin d’Hères]
2 PCC - Physico-Chimie-Curie
3 ESPCI Paris - Ecole Superieure de Physique et de Chimie Industrielles de la Ville de Paris
4 IL - Institut Langevin - Ondes et Images (UMR7587)

Determining the structure and the internal dynamics of tissues is essential to understand their functional organization. Microscopy allows monitoring positions and trajectories of every single cell. Those data are useful to extract statistical observables, such intercellular distance, tissue symmetry and anisotropy, and cell motility. However, this procedure requires a large and supervised computational effort. In addition, due to the large cross-section of cells, the light scattering limits the use of microscopy to relatively thin samples. As an alternative approach, we propose to take advantage of light scattering and to analyze the dynamical diffraction pattern produced by a living tissue illuminated with coherent light. In this article, we illustrate with few examples that supra-cellular structures produce an exploitable diffraction signal. From the diffraction signal, we deduce the mean distance between cells, the anisotropy of the supra-cellular organization and, from its fluctuations, the mean speed of moving cells. This easy to implement technique considerably reduces analysis time, allowing real time monitoring.

Domaines: Biophysique [physics.bio-ph]

Benjamin Brunel, Carles Blanch, Aurélien Gourrier, Vanni Petrolli, Antoine Delon, et al.. Structure and dynamics of multicellular assemblies measured by coherent light scattering. New Journal of Physics, 2017, ⟨10.1088/1367-2630⟩. ⟨hal-01525521⟩