A development of repetitious mechanical stress loading system for cultured cells.

在项目开始时，我们使用自制的应力加载系统获得了适当的强度和机械应力循环加载到骨细胞上的基本标准。在零件的耐久试验中，我们发现原来的电磁铁驱动系统在CO_2保温箱中不耐用，我们将该系统改为防水电机驱动-凸轮传动系统。这一变化除了耐用性外，还带来了一些好处。通过改变凸轮的形状，使往复运动中的加速过程变得可控，这是电磁铁驱动系统所不能做到的。经过一年的试制和改造，该系统建成了一台具有以下特点的机器：1.通过拉伸作为胶原胶的增强剂的尼龙网，使镶嵌在胶原凝胶薄层中的细胞承受反复的机械应力。通过改变电机的转速和凸轮的形状，不仅可以控制往复运动中拉伸和循环的距离，而且可以控制往复运动中的加速过程。胶原蛋白凝胶层足够薄(约1毫米)，可以忽略通过重复拉伸增加营养物质对凝胶的渗透性的影响。此外，您可以设置循环控制的样本，它在介质中往复运动而不进行任何拉伸，或者设置稳定控制的样本，它在介质中停顿。这些特征使人们有可能区分机械冲击的真实效果。在应激负荷期间，直接显微镜观察胶原层中的细胞是可能的。这使得测量电池上的FORTH负荷量作为电池的变形量，并将从不同机器获得的数据进行比较成为可能。经耐久试验和两年的使用测试，该系统具有良好的质量。

At the start of project, we obtained the basic dotards for an appropnate strenght and cycle of mechanical stress to load on bone cells using our hand-made stress loading system. During an endurance test of parts, we realized that the solenoid driving system is not durable in CO_2 incubator, and we change the system to waterproof motor driving-cam transmitting system. This change brought some merits besides a durability. An accelerating process in reciprocating movement became controllable with changing a shape of cam, which was impossible for solenoid driving system. A manufacture for trial and reform were repeated for a year and the system was completed as a machine with features,1. A repetitious mechanical stress is loaded for cells embedded in thin layr of collagen gel by stretching a nylon mesh, which is a reinforcement for cllagen gel. Not only a distance of stretch and cycle but also an accelerating process in reciprocating movement is controllable with changing the speed of motor and the shape of cam.2. A collagen gel layr is thin enough (about 1 mm) to neglect the effects of increasing permeability of nutrition into the gel according a repetitious stretch. Moreover, you can set a sample for cyclic control, which moves in the medium reciprocally without any stretch, or a sample for stable control, which standstill in the medium. These features make it possible to distinguish the true effect of mechanical forth.3. A direct microscopic observation of cells in collagen gel layr during the load of stress is possible. This makes it possible to measure the amount of forth loaded on cells as an amount of deformation of cells, and to compare the data obtained from different machines.It was confirmed by an endurance test and two years use for test that this system has a good quality.