TENSILE INTEGRITY ACROSS THE SCALES OF THE LIVING MATTER: A STRUCTURAL PICTURE OF THE HUMAN CELL

Tensile integrity principle governs the existence of stable constructs in which sets of pre-tensed cables and pre-compressed struts mutually interconnect according to specific topological rules and exchange forces in a way to guarantee the structure’s overall self-equilibrium. Starting from the simplest form of 2-element bow-like system, several structural components can be arranged together to assemble increasingly intricate tensegrity architectures where bars levitate sustained by a precise interplay with tensed cables, whose peculiar organization balances the vector field of axial forces. Modulation of the internal pre-stress tunes tensegrity systems towards disparate forms with different rigidities and stored elastic energies, while the floating arrangement of the compressed elements and the possible chirality confer to the whole structure pronounced deployability. This makes tensile integrity a persuasive structural paradigm for explaining and reproducing some underlying mechanisms at the basis of several dynamics experimentally observed in single cells as well as at different scales of biological architectures. In particular, by deeply exploring the intra-cellular environment, one discovers that the cytoskeleton mechanically sustains the cell’s membrane, structurally integrates cellular sub-constituents and steers migration, adhesion and division activities by behaving as a dynamic tensegrity lattice, hierarchically assembled by protein filaments, in turn made of continuously reacting polymeric tensegrity-chains at the lower nano-scale.