Department of Biomedical Engineering, National Taiwan University, Taipei, Taiwan.
Brain Research Center, National Yang Ming University, Taipei, Taiwan.
Ultrasound Med Biol. 2021 Jul;47(7):1775-1784. doi: 10.1016/j.ultrasmedbio.2021.03.020. Epub 2021 Apr 27.
Modulation of intra-cellular calcium by ultrasound offers a possible means for therapeutic applications. One such possibility is the modulation of nucleus pulposus cells as a preventive measure for inter-vertebral disc degeneration. We report a cellular stimulation device (micro-pipette ultrasound) using a glass micro-pipette as a waveguide to deliver ultrasound through the pipette tip and to elevate intra-cellular calcium in nucleus pulposus cells. The device generates two relevant stimuli at the cellular level: ultrasound propagation throughout the cell and acoustic streaming on the apical side. Ultrasound is radiated from a tip of a few microns, and its amplitude is proportional to the input voltage; acoustic streaming can be controlled by the duty factor. The novelty of the device is to impose a unique cellular loading: shear stress on cell apical surfaces combined with compressional waves propagating through the cells. G protein-coupled receptors and acid-sensing ion channel 3 were shown to play a role in calcium elevation by micro-pipette ultrasound in nucleus pulposus cells. Our results demonstrate that micro-pipette ultrasound can be an effective tool to elevate intra-cellular calcium levels in different cells, facilitating the identification of different mechanoreceptors in action.
超声对细胞内钙的调节为治疗应用提供了一种可能的手段。一种可能性是调节髓核细胞作为预防椎间盘退变的一种措施。我们报告了一种细胞刺激装置（微管超声），该装置使用玻璃微管作为波导，通过微管尖端传递超声，并升高髓核细胞内的钙。该装置在细胞水平上产生两种相关的刺激：超声在整个细胞中的传播和顶端的声流。超声从几微米的尖端辐射，其幅度与输入电压成正比;声流可以通过占空比来控制。该装置的新颖之处在于施加独特的细胞负荷：细胞顶表面的剪切应力与穿过细胞传播的压缩波相结合。研究表明，微管超声可通过 G 蛋白偶联受体和酸敏感离子通道 3 升高髓核细胞内的钙。我们的结果表明，微管超声可以成为一种有效工具，可升高不同细胞内的钙水平，有助于鉴定不同的机械感受器的作用。
