Cell adhesion mechanisms and stress relaxation in the mechanics of tumours
Cell adhesion mechanisms and stress relaxation in the mechanics of tumours
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DOI：
10.1007/s10237-008-0145-y
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发表时间：
2009-10-01
影响因子：
3.5
通讯作者：
Preziosi, Luigi
中科院分区：
文献类型：
--
作者：
Ambrosi, Davide;Preziosi, Luigi
肿瘤细胞通常生活在由其他宿主细胞、细胞外基质和细胞外液体形成的环境中。由于粘附分子施加可测量强度的力，细胞在相互结合时复制、重组和变形。本文研究了考虑这种粘附机制的实体瘤宏观力学模型。细胞外基质被视为一种弹性可压缩材料，同时，为了定义细胞成分的应力和应变之间的关系，变形梯度以乘法方式分解，区分由于生长，细胞重排和弹性变形的贡献。在细胞水平上的实验结果的基础上，提出在宏观水平上存在一个分离弹性和耗散状态的屈服条件。以前提出的模型是作为极限情况获得的，例如，在快速细胞重组和可忽略屈服应力的极限下获得的类流体模型。一个数值测试案例表明，该模型能够解释几种复杂的相互作用：肿瘤生长如何受到压力的影响，它如何以及在哪里产生细胞重组以释放压力水平，它如何导致包膜形成和周围组织的压缩。
Tumour cells usually live in an environment formed by other host cells, extra-cellular matrix and extra-cellular liquid. Cells duplicate, reorganise and deform while binding each other due to adhesion molecules exerting forces of measurable strength. In this paper, a macroscopic mechanical model of solid tumour is investigated which takes such adhesion mechanisms into account. The extracellular matrix is treated as an elastic compressible material, while, in order to define the relationship between stress and strain for the cellular constituents, the deformation gradient is decomposed in a multiplicative way distinguishing the contribution due to growth, to cell rearrangement and to elastic deformation. On the basis of experimental results at a cellular level, it is proposed that at a macroscopic level there exists a yield condition separating the elastic and dissipative regimes. Previously proposed models are obtained as limit cases, e.g. fluid-like models are obtained in the limit of fast cell reorganisation and negligible yield stress. A numerical test case shows that the model is able to account for several complex interactions: how tumour growth can be influenced by stress, how and where it can generate cell reorganisation to release the stress level, how it can lead to capsule formation and compression of the surrounding tissue.