Experimental Study for Active Control of Bubble-Surrounded Cells by Acoustic Radiation Force with Considering Optimal Production and Cell Viability

• Published in: 2018 IEEE International Ultrasonics Symposium (IUS) pp. 1 - 9
• Main Authors: Masuda, Kohji, Otsuka, Takuya, Seki, Masakazu, Oitate, Riki, Unga, Johan, Suzuki, Ryo, Maruyama, Kazuo
• Format: Conference Proceeding
• Language: English
• Published: IEEE 01.10.2018
• Subjects: Acoustic radiation force; Active induction; Bubble-surrounded cells; Cell viability; Standing wave; Trapping
• ISSN: 1948-5727
• DOI: 10.1109/ULTSYM.2018.8579669

Although cellular immunotherapy reduces side effects, where the therapeutic cells are injected into the bloodstream, there is a fundamental problem of the limitation of accumulation at the target area. Therefore, we proposed a method to produce bubble-surrounded cells (BSCs) by attracting microbubbles to the surface of cells to reduce their density and to be propelled using an acoustic radiation force. First, we confirmed cell viability in BSCs with various conditions of ultrasonic exposure. The cell viability in a BSC was guaranteed with more than 70 % under continuous ultrasound exposure with the maximum sound pressure of 400 kPa-pp unless the net exposure time exceeds 30 s. Then, we realized active induction of BSCs to the desired path at a bifurcation in an artificial blood vessel in a standing wave, where we found that the induction performance of the BSCs was enhanced at a frequency of 5 MHz rather than 3 MHz. In contrast, trapping performance of BSCs decreased using 5 MHz for induction, whereas 3 MHz was the most effective to trap much BSCs as possible. Considering these results, we considered that the surrounded bubbles on the surface of the cells are dominant for active control of BSCs.