From mechanical resilience to active material properties in biopolymer networks

Binding dynamics of alpha-actinin-4 in dependence of actin cortex tension

“…Therefore, tension-regulated manipulation of cross-linking lifetimes and cross-link concentration represents an intriguing mechanism for the cell to tune its cytoskeletal structure, stiffness and mechanical relaxation times through cytoskeletal tension. In particular, understanding and quantifying tension-dependence of actin crosslinker binding is key for the understanding of nonlinear material properties of the cytoskeleton [28][29][30] . The approach presented here now allows to systematically study to which extent this mechanism is implemented in cells.…”

Mechanochemical Adhesion and Plasticity in Multifiber Hydrogel Networks

“…Natural biopolymers, such as those that comprise the fibrillar extracellular matrix (ECM), have force‐responsive (i.e., mechanochemical) properties that allow tissues to adapt to mechanical load . For example, in response to strain, fibrillar proteins (e.g., collagen and fibrin) undergo acute non‐linear changes in stiffness (e.g., strain‐stiffening) and interfiber bonding, that result in plastic deformation and changes in material structure and mechanics .…”

“…Natural ECM has mechanochemical properties that allow the ECM to adapt to loading . Although efforts have been made to model these properties in materials, none have done so without the addition of external inputs (e.g., additional monomer and chemical treatments) and while maintaining the important fibrous network architecture observed in the ECM . Here, we combined multifiber electrospinning with complementary dynamic chemistry (i.e., hydrazone bonds) to fabricate adhesive fibrous hydrogel networks where mechanical loading induces fibers to come into contact for the reaction of chemical groups on the various fiber populations.…”

“…Natural biopolymers, such as those that comprise the fibrillar extracellular matrix (ECM), have force-responsive (i.e., mechanochemical) properties that allow tissues to adapt to mechanical load. [1] For example, in response to strain, fibrillar proteins (e.g., collagen and fibrin) undergo acute non-linear changes in stiffness (e.g., strain-stiffening) [2] and interfiber bonding, [3,4] that result in plastic deformation and changes in material structure [5,6] and mechanics. [7] The incorporation of these mechanochemical features of natural fibrous proteins into synthetic www.advmat.de www.advancedsciencenews.com each other after fabrication; however, under mechanical load, the fibers are brought into close enough proximity (e.g., physical contact between fibers) so that a chemical reaction can occur (e.g., the formation of hydrazone bonds from the interaction of aldehydes and hydrazides; Figure 1b).…”

“…[3,5,7,25] Although efforts have been made to model these properties in materials, [10][11][12] none have done so without the addition of external inputs (e.g., additional monomer and chemical treatments) and while maintaining the important fibrous network architecture observed in the ECM. [1] Here, we combined multifiber electrospinning with complementary dynamic chemistry (i.e., hydrazone bonds) to fabricate adhesive fibrous hydrogel networks where mechanical loading induces fibers to come into contact for the reaction of chemical groups on the various fiber populations. These materials have force responsive self-adhesive properties, which can be utilized to impart changes is stiffness, geometry, and microscale anisotropy with mechanical loading, as well for the fabrication of complex structures via the adhesion of adjacent fibrous materials.…”