Emergent mechanics of biological structures.
Bottom Line: Unlike the engineered macroscopic structures that we commonly build, biological structures are dynamic and self-organize: they sculpt themselves and change their own architecture, and they have structural building blocks that generate force and constantly come on and off.A description of such structures defies current traditional mechanical frameworks.It requires approaches that account for active force-generating parts and for the formation of spatial and temporal patterns utilizing a diverse array of building blocks.
Affiliation: Department of Cell and Tissue Biology and Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA 94143-0512 email@example.com.Show MeSH
Mentions: Moving to a larger length scale, that of multicellular organisms, how can we comprehend the physical properties of a large cluster of homogeneous or heterogeneous cells? From the outset, calling an aggregate of cells or a tissue “dynamic” may seem paradoxical. After all, our common macroscopic perception of a tissue is static and fixed—a structure that resists stress and maintains the mechanical integrity of organs. However, at the microscopic scale of individual cells, a very different (and dynamic) story emerges, as is readily seen during development and tissue maintenance and homeostasis (Guillot and Lecuit, 2013). From the early proposals of differential adhesion theory, cellular ensembles have been described as being like a fluid with specific surface tension associated with cellular interfaces (Foty and Steinberg, 2005). For decades, we have known that macroscopic cellular rearrangements play a critical role in morphogenesis at developmental time scales. Mature tissue has also been uncovered to have the plasticity to recover from injury and trauma and to maintain homeostasis, for example, in the kidney (Rabelink and Little, 2013). Thus the conceptual challenges described above for understanding the mechanics of macromolecular assemblies are similar at multicellular scales (Figure 2).
Affiliation: Department of Cell and Tissue Biology and Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA 94143-0512 firstname.lastname@example.org.