Résumé
The aim of this work is to provide a rheological description of biomimetic tissues in microfluidic confinement, as a simplified model for the flow of cellular tissues observed in complex physiological problems such as in embryogenesis or tumour metastasis. We designed a microfluidic chip that allowed us to tune the assembly of GUVs and to synthesize prototissues with controlled shape and size. GUV-GUV adhesion was mediated by the inclusion of complementary DNA strands enabling the control of prototissue cohesivity and the quantification of GUV-GUV adhesion by fluorescence microscopy. Rheological properties of prototissues were probed in a “pipette-aspiration” inspired microfluidic device, under controlled pressure conditions (creep test). We reported a viscoelastic response, which was well captured by a generalized Kelvin-Voigt fluid model. The prototissue rheology was complemented with a velocimetry analysis which allowed us to identify spatial reorganizations taking place within the prototissue, and with the quantification of the deformation field at the scale of individual vesicles.