Study on the Dynamic Properties of Living-Cells from the viewpoint of Intelligent Vibration-Reducible Structure

生物基本上是由细胞组成的，细胞可以适应他们的环境；他们聚集在一起寻找相同类型的细胞，排除对它们的不方便的刺激，保持最好的生命保护条件。虽然细胞在生物学、医学、生物化学等领域都有过处理，但作为微型机械的原型，它们可能会受到机械工程师的关注。但是，几乎没有关于细胞的机械性能的研究。本项目致力于揭示活细胞的力学特性，并将其应用于构建更智能的结构。本研究采用骨相关细胞作为活细胞，骨细胞具有对周围力学条件的适应性。据报道，负责骨形成的成骨细胞对机械振动做出反应，改变了细胞的增殖和产生的骨量。为了找到有效的刺激…更多关于成骨，有必要从机械工程学的角度了解细胞的弹性或粘性等力学性质。就骨细胞而言，由于它们附着在骨基质的表面，因此了解它们在粘连条件下的力学性能是很重要的。在这项研究中，我通过施加正弦形变法测量了培养的成骨细胞MC3T3-E1在粘连条件下的动态粘弹性。利用这些实验结果，我们推导出了粘弹性的Voigt模型，并确定了每个参数的值。然后，评估了机械刺激的效果。对骨骼的机械刺激会影响成骨，如宇航员在失重状态下的骨量减少，以及使用超声波设备修复骨折等。骨细胞已被报道在细胞水平、形态和代谢水平上对机械刺激进行感知和反应。从机械振动的角度来看，骨细胞是根据机械刺激及其力学特性而发生变形的。据报道，细胞的粘弹性是通过拉伸和蠕变实验测量的，在结构动力学的意义上，细胞可能存在固有频率和非线性。提示机械刺激对骨细胞成骨的作用存在有效频率和幅度。本研究将正弦惯性力作用于培养的成骨细胞MC3T3-E1，从细胞增殖、骨基质生成和碱性磷酸酶(ALP)基因表达的角度，研究了机械振动的频率和加速度对细胞增殖的影响。较少

Living creatures are fundamentally composed of cells, which may adapt to their environment; they get together finding the same kind of cells, exclude inconvenient stimulus to them, and keep the best condition for life conservation. Though the cells have been treated in biology, medical science, or bio-chemistry, they may be paid attention by mechanical engineers when they are regarded as a prototype of micro-machine. But, almost nothing has been studied as for the mechanical properties of cells. This project is concentrated to reveal mechanical properties of living cells and they are applied to construct more intelligent structures. As living cells, a bone related cell are used in this study.Bone cells have adaptability to the surrounding mechanical condition. Osteoblasts, which are responsible for bone formation, were reported that they responded to mechanical vibration and changed the cell proliferation and the amount of generated bone mass. In order to find the effective stimulation … More on osteogenesis, it is necessary to understand the mechanical properties such as elasticity or viscosity of the cells in the view of mechanical engineering. In the case of bone cells, it is important to understand the mechanical properties under adhesive condition because they attach on surfaces of bone matrices. In this study, I measured dynamic viscoelasticity of a cultured osteoblast, MC3T3-E1, under adhesive condition by applying sinusoidal deformation. Using these experimental results, we derived Voigt model for viscoelasticity and identified the value of each parameter.Next, the effect of mechanical stimulation was evaluated. Mechanical stimulation to bones affects osteogenesis such as decrease of bone mass of astronauts under zero gravity and fracture repair with ultrasound devices. Bone cells have been reported to sense and response to mechanical stimulation at cellular level morphologically and metabolically. In the view of mechanical vibrations, bone cells are deformed according to mechanical stimulation and their mechanical characteristics. It was reported that viscoelasticity of cells was measured using tensile and creep tests and that there was likely natural frequency and nonlinearity of cells in the sense of structural dynamics. It suggests that there is effective frequency and amplitude of mechanical stimulation on osteogenesis by bone cells. In this study, sinusoidal inertia force was applied to cultured osteoblasts, MC3T3-E1, and effects of frequency and acceleration amplitude of mechanical vibration on the cells were investigated in respect of the cell proliferation, bone matrix generation and alkaline phosphatase (ALP) gene expression. Less