Ultrasound-mediated Delivery of Natural Killer Cells with Microbubble for Cancer Treatment

In this paper, NK cells conjugated with microbubbles (Sonazoid) are proposed to control and image the NK cells by focused ultrasound. We verified that the NK cells were successfully conjugated with Sonazoid. Moreover, the Sonazoid-conjugated NK cells (NK_Sona cells) were more controlled by ultrasound blocking than NK cells in a Y channel phantom model. The regulated NK_Sona cells were clearly imaged using a transducer of the ultrasound system. We also examined the targeting effect of focused ultrasound about NK_Sona cells in the subcutaneous (s.c.) tumor mice model. The intravenously injected NK_Sona cells were more targeted into the subcutaneous tumor under ultrasound exposure than only NK_Sona cells without ultrasound exposure. Consequently, our developed NK_Sona cells could be imaged and controlled by ultrasound, and further research is needed to improve the performance of NK_Sona cells to use medical applications.