一种体外贴壁细胞应变加载装置的研制

目的开发一套新型的应变加载装置,用于贴壁细胞力学生物学研究。方法该装置基于基底形变加载技术,采用可控制编程器驱动步进器,引起硅橡胶小室变形,实现多单元大应变的细胞加载;研制该装置,检测机械性能;建立硅橡胶小室的三维模型,利用有限元技术对硅橡胶小室进行仿真,分析该小室的应变场均匀性问题;采用该装置对骨髓间充质干细胞(bone marrow stromal cells,BMSCs)加载5%机械应变,频率0.5 Hz,2 h/d,持续5 d,并在倒置显微镜下观察细胞形态的变化。结果所研制的适用于体外细胞加载装置可对3组细胞加载基底实现最大至50%机械单向应变;在10%应变范围内,硅橡胶小室底部的均匀应变场面积占比保持在50%以上,保证了细胞受力均匀; BMSCs形态发生明显变化,排列方向趋于垂直主应变加载方向。结论该装置运行可靠,应变范围宽,频率可调,操作方便,可同时对多组细胞培养基底进行应变加载,为细胞力学生物学研究提供了便利条件。

Development of Strain Loading Device for Adherent Cells in vitro

Objective To design a novel strain loading device for studying the mechanical biology of adherent cells. Methods Based on the technology of substrate deformation loading, the device adopted controllable stepper to cause deformation of the silastic chamber, so as to realize cell loading with multiple units and large strain. The device was developed to test its loading functions. The three-dimensional (3D) models of the silastic chamber were established to simulate the loaded chamber by the finite element technology, and uniformity of the strain field was analyzed. The device applied 5% strain to bone marrow stromal cells (BMSCs) with 0.5 Hz stretch frequency at 2 hours per day for 5 days, and an inverted phase contrast microscope was used to observe the morphology of BMSCs. Results The developed strain loading device for adherent cells in vitro could provide mechanical unidirectional strain up to 50% with three groups of cell loading substrates; within the 10% stain range, the area of uniform strain filed on the silastic chamber remained above 50%, which ensured that the cells were loaded evenly; the morphology of BMSCs was obviously altered, and the direction of arrangement tended to be perpendicular to the loading direction of principal strain. Conclusions The device shows the advantages of reliable operation, wide strain range, adjustable frequency and convenient operation. It can be used to load multiple cell culture substrates at the same time, which provides convenient conditions for the study of cell mechanobiology.