Track synthesis, materials and catalysis as it is published.
Search papers, labs, and topics across Lattice.
The authors investigate how cellular contractility remodels the extracellular matrix (ECM) into aligned, high-stress fiber networks that mechanically couple distant cells into functional clusters. Using finite-element modeling of active contractile inclusions in a nonlinear biopolymer gel alongside experimental validation, they analyze how matrix mechanics govern long-range collective organization. They find that mechanical percolation and bulk internal stiffening emerge at an exceptionally low cell volume fraction of roughly 10%, bypassing standard geometric contact thresholds via nonlinearly reinforced stress bands.
Sparse populations of contractile cells can globally stiffen and percolate tissue at just 10% volume fraction, bypassing physical contact thresholds entirely through nonlinear matrix-mediated stress bands.
Tissues are composites of living cells and extracellular matrix (ECM), that jointly determine their unique mechanical behavior. Here, we experimentally demonstrate that contractile cells remodel the ECM by generating long-range bands of aligned and densified fibers that mechanically couple cells into multicellular clusters. Using a finite-element model, we quantify the collective mechanical interactions mediated by these ECM bands for various volume fractions of cells. The model incorporates contractile particles that mimic cell-active forces within a nonlinear biological gel, inducing stiffening internally rather than through external loading. We find that even a small volume fraction of contractile particles (approximately 10%), much below what is expected for percolation of sphere contacts, leads to internal stiffening, mediated by the high-concentrated stress bands between cells and is strongly dependent on the nonlinear mechanical response of the ECM. Percolation analysis of the band network reveals sharp transitions at a critical particle volume fraction, that aligns with the onset of internal stiffening. These results demonstrate that long-range interaction between contractile cells through the deformation of the medium has the potential to globally shape the structure and mechanics of the bulk gel, leading to a functional structure with modified properties. These modified macroscopic changes can define organizing principles in tissue patterning and morphogenesis.