Chu Y.-CLim JLai C.-HTseng M.-CChu Y.-SWang J.-L.JAW-LIN WANG2021-08-052021-08-0520213015629https://www.scopus.com/inward/record.uri?eid=2-s2.0-85107103090&doi=10.1016%2fj.ultrasmedbio.2021.03.020&partnerID=40&md5=8f3a7ec59f5146bde7d7b6323f912721https://scholars.lib.ntu.edu.tw/handle/123456789/577149Modulation 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. ? 2021 World Federation for Ultrasound in Medicine & BiologyAcoustic streaming; Cells; Cytology; Modulation; Shear flow; Stress analysis; Calcium imaging; Cellular stimulation; Cellulars; Inter-vertebral disc degeneration; Micro-pipette; Micro-pipette ultrasound; Nucleus pulposus; Preventive measures; Stimulation devices; Therapeutic Application; Calcium[SDGs]SDG3journal article10.1016/j.ultrasmedbio.2021.03.020339312852-s2.0-85107103090