Cytodetachment Technique Using Ultrasonic Vibration
Ultrasonic vibration is often used in tissue engineering, for example, to provide effective mechanical stimuli for cell growth. This study aims for adherent cells to be effectively detached from a culturing substrate by using ultrasonic vibration. First, a cell detachment device using ultrasonic vibration is designed and fabricated. The first out-of-plane natural vibration mode of a stainless steel cultivation substrate is adopted. Then, we compared cell detachment abilities between the conventional trypsin-pipetting treatment and the trypsin-ultrasonic vibration treatment with calf chondrocytes. In case of low concentration of trypsin, the number of cells detached with the trypsin-ultrasonic vibration treatment is much larger than that with the conventional method. This result suggests that ultrasonic vibration encourages trypsinization in the process of cell detachment compared with conventional pipetting. In addition, we observed the cells remaining on the substrate after the ultrasonic vibration. The density of cells after the ultrasonic vibration treatment is lower than the initial state. However, the density of remained cells is the highest at the vibration node. As is obvious from the result, the cells are much effectively detached in the higher amplitude region than the lower amplitude region.