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机械应力强度和周期对骨细胞加载的基本数据。在对零件进行耐久性试验时，发现原电磁铁驱动系统在CO_2培养箱中使用寿命不长，于是将原系统改为防水电机驱动-凸轮传动系统。这种变化带来了一些好处，除了耐用性。通过改变凸轮的形状，使往复运动的加速过程变得可控，这是螺线管驱动系统所不能做到的。经过一年的试制和改革，该系统已建成一台性能优良的机器。通过拉伸尼龙网片对包埋在胶原凝胶薄层中的细胞施加重复的机械应力，尼龙网片是胶原凝胶的增强物。通过改变电机转速和凸轮形状，不仅可以控制拉伸和循环的距离，而且可以控制往复运动的加速过程.胶原蛋白凝胶层足够薄（约1 mm），以忽略根据重复拉伸增加营养渗透到凝胶中的效果。此外，您还可以设置一个用于循环控制的样品，它在介质中移动，没有任何拉伸，或者一个用于稳定控制的样品，它在介质中静止。这些特征使我们有可能区分机械摩擦的真实效果.在应力负荷期间，可以直接显微镜观察胶原凝胶层中的细胞。这使得可以测量作为电池变形量的电池上的前负荷量，并比较从不同机器获得的数据。通过耐久性试验和两年的使用试验证实，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.