Matrix-mediated symmetry breaking of single cells in a three-dimensional space

Cells often undergo symmetry breaking in various physiological and developmental processes. While symmetry breaking of cells can occur spontaneously, spatial distribution of external signals from microenvironments, such as adhesion ligands from the extracellular matrix can also direct this process. While micropatterning was previously used to show cellular symmetry breaking on two-dimensional substrates, it remains unclear how this process occurs in a three-dimensional (3D) environment. To address this question, we developed a droplet-based microfluidic approach to encapsulate single cells between two different hydrogel compartments where ligand composition of each compartment can be independently controlled. We show that asymmetric presentation of an integrin adhesion ligand accelerates cell volume expansion with slightly decreased sphericity than symmetric presentation, while overall cell geometry is still symmetric. In contrast, membrane tension remains higher on the side of single cells interacting with the adhesion ligand than the side without the ligand. This suggests that there exists a mechanism to consolidate symmetry breaking of membrane tension despite that cell volume expansion occurs symmetrically. At a longer timescale, asymmetric distribution of the adhesion ligand enhances osteogenic differentiation of mesenchymal stem cells. This study highlights the utility of our approach in understanding biophysical mechanisms of cellular symmetry breaking in a 3D space with potential implications in directing cell fate decision.