Power-law rheology and mechano-sensing in a cytoskeleton model with forced protein unfolding

Cell nucleus as a microrheological probe to study the rheology of the cytoskeleton

Mechanical properties of the cell are important biomarkers for probing its architectural changes caused by cellular processes and/or pathologies. The development of microfluidic technologies have enabled measuring cell mechanics at high-throughput, so that mechanical phenotyping can be applied to large samples in reasonable time-scales. These studies typically measure the stiffness of the cell as the only mechanical biomarker, and cannot disentangle the rheological contribution of different structural components of the cell, including the cell cortex, the interior cytoplasm and its immersed cy…

通过细胞骨架网络中的机械敏感性和活动性进行学习

Learning via mechanosensitivity and activity in cytoskeletal networks

本文提出一种基于肌动球蛋白细胞骨架的机械敏感网络，在对比学习框架下从环境扰动中学习，为生物系统学习提供原理验证，并探讨其对适应与稳态的意义。

Rheology of fractal networks

We model the cytoskeleton as a fractal network by identifying each segment with a simple Kelvin-Voigt element, with a well defined equilibrium length. The final structure retains the elastic characteristics of a solid or a gel, which may support stress, without relaxing. By considering a very simple regular self-similar structure of segments in series and in parallel, in 1, 2 or 3 dimensions, we are able to express the viscoelasticity of the network as an effective generalised Kelvin-Voigt model with a power law spectrum of retardation times, $\cal L\simτ^α$. We relate the parameter $α$ with t…

活细胞拥挤细胞质的单一幂律流变学

Single power-law rheology of crowded cytoplasm in living cells

本研究采用 3D 反馈微流变学技术，发现除 ATP 耗竭外，活细胞拥挤细胞质在宽频范围内普遍遵循单一幂律流变学 $G(ω)\propto(-iω)^{0.5}$，揭示了分子拥挤是决定细胞质力学普遍性的关键物理基础。

Nonequilibrium dynamics of probe filaments in actin-myosin networks

Active dynamic processes of cells are largely driven by the cytoskeleton, a complex and adaptable semiflexible polymer network, motorized by mechanoenzymes. Small dimensions, confined geome- tries and hierarchical structures make it challenging to probe dynamics and mechanical response of such networks. Embedded semiflexible probe polymers can serve as non-perturbing multi-scale probes to detect force distributions in active polymer networks. We show here that motor-induced forces transmitted to the probe polymers are reflected in non-equilibrium bending dynamics, which we analyze in terms of …

预应力细胞骨架丝网络的离散到连续模型

Discrete-to-continuum models of pre-stressed cytoskeletal filament networks

本文提出离散到连续的细胞骨架力学模型，用于预测预应力蛋白丝网络的力学响应，并验证了模型在波形蛋白网络中的有效性，发现刚度随预应力和珠子尺寸呈特定标度关系。