Browsing by Author "Mao, Xiaoming"

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    Alignment and nonlinear elasticity in biopolymer gels
    (American Physical Society, 2015) Feng, Jingchen; Levine, Herbert; Mao, Xiaoming; Sander, Leonard M.; Center for Theoretical Biological Physics
    We present a Landau-type theory for the nonlinear elasticity of biopolymer gels with a part of the order parameter describing induced nematic order of fibers in the gel. We attribute the nonlinear elastic behavior of these materials to fiber alignment induced by strain. We suggest an application to contact guidance of cell motility in tissue. We compare our theory to simulation of a disordered lattice model for biopolymers. We treat homogeneous deformations such as simple shear, hydrostatic expansion, and simple extension, and obtain good agreement between theory and simulation. We also consider a localized perturbation which is a simple model for a contracting cell in a medium.
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    Stress-induced plasticity of dynamic collagen networks
    (Springer Nature, 2017) Kim, Jihan; Feng, Jingchen; Jones, Christopher A.R.; Mao, Xiaoming; Sander, Leonard M.; Levine, Herbert; Sun, Bo
    The structure and mechanics of tissues is constantly perturbed by endogenous forces originated from cells, and at the same time regulate many important cellular functions such as migration, differentiation, and growth. Here we show that 3D collagen gels, major components of connective tissues and extracellular matrix (ECM), are significantly and irreversibly remodeled by cellular traction forces, as well as by macroscopic strains. To understand this ECM plasticity, we develop a computational model that takes into account the sliding and merging of ECM fibers. We have confirmed the model predictions with experiment. Our results suggest the profound impacts of cellular traction forces on their host ECM during development and cancer progression, and suggest indirect mechanical channels of cell-cell communications in 3D fibrous matrices.