Coherent Timescales and Mechanical Structure of Multicellular Aggregates

摘要: Abstract Multicellular aggregates are an excellent model system to explore the role of tissue biomechanics in specifying multicellular reorganization during embryonic developments and malignant invasion. Tissue-like spheroids, when subjected a compressive force, known exhibit liquid-like behaviors at long timescales (hours), largely because cell rearrangements that serve effectively dissipate applied stress. At short (seconds minutes), before rearrangement, mechanical behavior is strikingly different. The current work uses shape relaxation investigate structural characteristics discovers two coherent timescales: one on order seconds, other tens seconds. These universal, conserved across variety tested species, persist despite great differences properties such as surface tension adhesion. A precise mathematical theory used correlate with reveals have relatively strong envelope unusually “soft” interior (weak bulk elastic modulus). This characteristic peculiar, considering both layers consist identical units (cells), but consistent fact this structure can engender integrity flexibility required for remodeling. In addition, tension, modulus, viscosity proportional each other. Considering these tissue-level intrinsically derive from cellular-level properties, proportionalities imply coregulation latter particular cell-medium cell-cell interfaces.