Introduction to force transmission by nonlinear biomaterials
Xiaoming Mao and Yair Shokef introduce the Soft Matter themed collection on force transmission by nonlinear biomaterials.
Non-linear elastic properties of actin patches to partially rescue yeast endocytosis efficiency in the absence of the cross-linker Sac6
Viscoelastic measurements of actin patches, using magnetic micro-cylinders, show that patches lacking a crosslinker are softer but stiffen with stress, allowing in some cases the build-up of elastic energy necessary for endocytosis.
Paper
Moduli and modes in the Mikado model
We determine how low frequency vibrational modes control the elastic shear modulus of Mikado networks, a minimal mechanical model for semi-flexible fiber networks.
Transient mechanical interactions between cells and viscoelastic extracellular matrix
A cell embedded in a matrix contracts, resulting in development of mechanical forces and structural changes in the matrix.
Effect of matrix heterogeneity on cell mechanosensing
(a,b) Images of collagen fibers (gray) next to mouse mammary tumors (cyan) illustrating regions of low (a) and high (b) fiber density. (c,d) Stiffness sensed by contracting in more heterogeneous (c) and more homogeneous (d) fiber networks with stiff inclusions located a distance d/R away.
Paper
Stress relaxation in tunable gels
Molecular dynamics shows how stress relaxation of tetra-PEG hydrogels with hybrid (permanent + reversible) crosslinks is set by the strength and concentration of the reversible bonds, which provides a way to improve the responsivity of these gels.
Viscoelasticity of 3D actin networks dictated by the mechanochemical characteristics of cross-linkers
In this study, we report a computational investigation on how the mechanochemical characteristics of crosslinking molecules influence the viscoelasticity of three dimensional F-actin networks, an issue of key interest in analyzing the behavior of living cells and biological gels.
Quantifying the link between local structure and cellular rearrangements using information in models of biological tissues
A machine-learning classifier predicts impending topological rearrangement in a model of dense tissue, extracting a large fraction of the total available information contained in local structure throughout the model’s parameter space.
Directed force propagation in semiflexible networks
We consider the propagation of tension along specific filaments of a semiflexible filament network in response to the application of a point force using a combination of numerical simulations and analytic theory.
A model for 3D deformation and reconstruction of contractile microtissues
The combination of high-throughput three-dimensional (3D) culture systems and experimentally-validated computational models accelerate the study of cell-ECM interactions and tissue-scale deformation.
Inverse method based on 3D nonlinear physically constrained minimisation in the framework of traction force microscopy
We present a new inverse and physically-consistent traction force microscopy method developed and implemented in the context of 3D nonlinear elasticity. We prove its enhanced accuracy applying it to real cases of cells cultured in a 3D hydrogel.
Tensile behavior of non-crosslinked networks of athermal fibers in the presence of entanglements and friction
A geometric definition of entanglements in athermal random networks is proposed and is linked to the network stiffness. Entanglements produce a self-equilibrated stress which increases the stiffness.
Spatiotemporal control of micromechanics and microstructure in acoustically-responsive scaffolds using acoustic droplet vaporization
Acoustic droplet vaporization (ADV) of phase shift emulsion (green) generates different bubble morphologies, and spatiotemporally tunes the micromechanics of fibrin gels (red).
Harnessing biomimetic cryptic bonds to form self-reinforcing gels
Cryptic sites, which lay hidden in folded biomolecules, become exposed by applied force and form new bonds that reinforce the biomaterial.
About this collection
This special issue, Guest Edited by Xiaoming Mao (University of Michigan) and Yair Shokef (Tel Aviv University) focuses on a wide variety of non-linear mechanical phenomena in biological contexts, and how they arise from the underlying fibrous structure of different biomaterials.
The issue presents contributions on theoretical, computational and experimental studies of natural, as well as synthetic, model systems, ranging from the molecular level, through the cellular level, to the tissue level. The results included in the collection will deal with the influence of non-linear mechanics on biological processes and also with mechanical features of biomaterials that are interesting in their own right.