Tatiana Kardashina , Elba E. Serrano , John A. Dawson , Borys Drach
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引用次数: 0
Abstract
Mechanical properties are essential for the biological activities of cells, and they have been shown to be affected by diseases. Therefore, accurate mechanical characterization is important for studying the cell lifecycle, cell-cell interactions, and disease diagnosis. While the cytoskeleton and actin cortex are typically the primary structural stiffness contributors in most live cells, oocytes possess an additional extracellular layer known as the vitelline membrane (VM), or envelope, which can significantly impact their overall mechanical properties. In this study, we utilized nanoindentation via an atomic force microscope to measure the Young's modulus of Xenopus laevis oocytes at different force setpoints and explored the influence of the VM by conducting measurements on oocytes with the membrane removed. The findings revealed that the removal of VM led to a significant decrease in the apparent Young's modulus of the oocytes, highlighting the pivotal role of the VM as the main structural component responsible for the oocyte's shape and stiffness. Furthermore, the mechanical behavior of VM was investigated through finite element (FE) simulations of the nanoindentation process. FE simulations with the VM Young's modulus in the range 20–60 MPa resulted in force-displacement curves that closely resemble experimental in terms of shape and maximum force for a given indentation depth.
机械特性对细胞的生物活动至关重要,而且已被证明会受到疾病的影响。因此,准确的机械特性分析对于研究细胞生命周期、细胞-细胞相互作用和疾病诊断非常重要。在大多数活细胞中,细胞骨架和肌动蛋白皮层通常是造成结构僵硬的主要因素,而卵母细胞则拥有一个被称为卵黄膜(VM)或包膜的额外细胞外层,它能显著影响细胞的整体机械特性。在这项研究中,我们通过原子力显微镜利用纳米压痕技术测量了不同力设定点下爪蟾卵母细胞的杨氏模量,并通过对去除了卵黄膜的卵母细胞进行测量来探索卵黄膜的影响。研究结果表明,去除 VM 后,卵母细胞的表观杨氏模量显著下降,这突出表明 VM 作为卵母细胞形状和刚度的主要结构成分所起的关键作用。此外,还通过对纳米压痕过程的有限元(FE)模拟研究了 VM 的机械行为。在有限元模拟中,VM 的杨氏模量范围为 20-60 兆帕,结果得出的力-位移曲线在形状和给定压痕深度的最大力方面与实验结果非常相似。
期刊介绍:
The Journal of the Mechanical Behavior of Biomedical Materials is concerned with the mechanical deformation, damage and failure under applied forces, of biological material (at the tissue, cellular and molecular levels) and of biomaterials, i.e. those materials which are designed to mimic or replace biological materials.
The primary focus of the journal is the synthesis of materials science, biology, and medical and dental science. Reports of fundamental scientific investigations are welcome, as are articles concerned with the practical application of materials in medical devices. Both experimental and theoretical work is of interest; theoretical papers will normally include comparison of predictions with experimental data, though we recognize that this may not always be appropriate. The journal also publishes technical notes concerned with emerging experimental or theoretical techniques, letters to the editor and, by invitation, review articles and papers describing existing techniques for the benefit of an interdisciplinary readership.