目的:设计一套细胞剪切力加载系统,可通过计算机对应力模式及参数进行控制,并验证系统设计的有效性和可行性.方法:使用蠕动泵和自行设计研制的多通道流体腔室进行细胞剪切力加载系统的硬件部分设计,同时设计一套基于LabVIEW软件的剪切力模式控制程序,通过RS485接口技术和Modbus协议实现计算机对细胞剪切力加载系统的程控.同时,对剪切力与系统参数进行标定和有限元仿真分析,并通过细胞实验验证该系统设计的可行性.结果:该系统能够利用蠕动泵或计算机控制选择不同模式和不同大小的剪切力,并可完成对细胞长期效应的观察.系统标定显示,蠕动泵转速与剪切力大小呈高度线性正相关关系(P<0.001).有限元仿真分析显示,流体剪切力大小在载玻片上分布均匀且仿真结果与标定结果相符.细胞骨架染色结果表明,骨细胞在接受流体剪切力刺激后,细胞形态改变,且微丝数量增多,排列方向沿流场分布.结论:该系统具有科学、稳定、可靠的特点,可针对不同实验要求提供不同类型的细胞剪切力加载模式,能够为不同细胞流体力学信号转导机制的探讨提供有力的平台支持.
Objective To develop a cellular shear stress loading system with an adjustable stress mode and relevant parameters, and subsequently verify the effectiveness and feasibility of this system. Methods The hardware of the system was developed by using a peristaltic pump and self-designed multi-channel flow chamber, and the mode control program of shear stress based on LabVIEW was designed to control the device via RS485 interfacing and Modbus protocol. Additionally, the relationship between the shear stress and system parameters was calibrated, and finite element analysis was also conducted. Finally, the feasibility of the system was confirmed via the in vitro cell experiment. Results The mode and magnitude of shear stress of the system could be controlled via either the peristaltic pump or computer, and the cellular long-term effect was also able to be detected. The calibration results of the system indicated that the level of shear stress exhibited significantly linear positive correlation with the revolution of the peristaltic pump (P<0.001). Finite element analysis demonstrated that the level of shear stress on the slide was uniformly distributed and the result of simulation was accordant with calibration. Cytoskeleton staining suggested that cellular morphology of MLO-Y4 cells was changed, and microfilament increased and arrayed along fluid flow direction. Conclusion The system is stable and reliable enough to provide different loading modes and magnitude of cellular shear stress to offer a convictive platform of the research for different cellular stress signal transduction mecha-nisms.