Mechanosensation of osteocyte with collagen hillocks and primary cilia under pressure and electric field stimulation  

压力与电场协同作用下具有初级纤毛和胶原小丘的骨细胞的力学响应研究

作　　者：Yan Wang Chaoxin Li Hao Dong Jianhao Yu Yang Yan Xiaogang Wu Yanqin Wang Pengcui Li Xiaochun Wei Weiyi Chen 王岩;李朝鑫;董浩;禹健豪;燕杨;武晓刚;王艳芹;李鹏翠;卫小春;陈维毅

机构地区：[1]College of Biomedical Engineering,Taiyuan University of Technology,Taiyuan 030024,China [2]Shanxi Provincial Key Laboratory for Repair of Bone and Soft Tissue Injury,Taiyuan 030001,China

出　　处：《Acta Mechanica Sinica》2022年第3期172-186,I0004,共16页力学学报（英文版）

基　　金：supported by the National Natural Science Foundation of China(Grant Nos.11972242,11632013,11702183);China Postdoctoral Science Foundation(Grant No.2020M680913).

摘　　要：Mechanosensors are the most important organelles for osteocytes to perceive the changes of surrounding mechanical environment.To evaluate the biomechanical effectiveness of collagen hillock,cell process and primary·cilium in lacunar-canalicular system(LCS),we developed pressure-electricity-structure interaction models by using the COMSOL Multiphysics software to characterize the deformation of collagen hillocks-and primary cilium-based mechanosensors in osteocyte under fluid flow and electric field stimulation.And mechanical signals(pore pressure,fluid velocity,stress,deformation)were analyzed in LCS.The effects of changes in the elastic modulus of collagen hillocks,the number and location of cell processes,the length and location of primary cilia on the mechanosensitivity and the overall poroelastic responses of osteocytes were studied.These models predict that the presence of primary cilium and collagen hillocks resulted in significant stress amplifications(one and two orders of magnitude larger than osteocyte body)on the osteocyte.The growth of cell process along the long axis could stimulate osteocyte to a higher level than along the short axis.The Mises stress of the basal body of primary cilia near the top of osteocyte is 8 Pa greater than that near the bottom.However,the presence of collagen hillocks and primary cilium does not affect the mechanical signal of the whole osteocyte body.The established model can be used for studying the mechanism of bone mechanotransduction at the multiscale level.骨细胞内的力学传感器是骨细胞感知周围力学环境变化的最重要的细胞器.为了评估骨陷窝骨小管系统(LCS)内胶原小丘、细胞突触和初级纤毛作为力学传感器的生物力学效应,我们利用COMSOL Multiphysics软件开发了一种压力-电场-结构相互作用的骨细胞模型,以描述在流体流动和电场刺激下LCS中胶原小丘,初级纤毛以及细胞突触作为骨细胞中力学传感器的力学感应效果.分析了LCS中的力学信号(孔隙压力、流体速度、应力、变形)并且研究了胶原小丘弹性模量的变化、细胞突触的数量和.位置、初级纤毛的长度和位置对骨细胞内力学传感器的力学敏感性以及骨细胞总体多孔弹性响应的影响.结果表明,初级纤毛和.胶原小丘的存在将会导致骨细胞部分位置产生明显的应力集中(比骨细胞体其他位置的应力大1-2个数量级).相比于细胞突触沿骨细胞短轴方向生长,沿长轴方向生长可以刺激骨细胞产生更大的应力.当初级纤毛位于骨细胞顶部时,初级纤毛基底的应力比初级纤毛位于骨细胞底部时大8 Pa.然而,胶原小丘和初级纤毛的存在并不影骨细胞整体的力学信号分布.所建立的模型可用于在多尺度水平上研究骨力学信号的传导机制.

关 键 词：OSTEOCYTE Cell Process Primary Cilium Collagen Hillock Finite Element 

分 类 号：O511.3[一般工业技术—材料科学与工程]