Acoustic and flow conditions for effective non-contact culturing of vascular endothelial cells using lipid bubbles

For application in the fabrication of artificial blood vessels, we developed a method for in situ culturing of vascular endothelial cells following a process of non-contact retention. Utilizing the propulsive force acting on cells under ultrasound exposure when the cells were surrounded by lipid bubbles, the conditions of the flow path were investigated. The cells were retained on the two types of inner surface of the flow path, which were a flat wall and a concave wall, using various acoustic fields including single-focal and bar-shaped fields. After culturing the cells in the path without flow for 24 h, the cultured area of cells were measured to evaluate the series of performance. When the bar-shaped fields and the concave wall in the flow path were used for the retention process, significant cell engraftment was observed compared to other conditions, even though the acoustic intensity of SATA (Spatial average temporal average) and the retained area of the cells were similar. Those results suggest that not only the shape of the acoustic field but also the wall condition in the flow path are clitical for non-contact culturing of cells following retention.