Acoustic field sweeping for active induction of bubble-surrounded T-cells

Abstract

Abstract Although immunotherapy has been recognized as a new therapeutic method, there is a problem of low cell concentration because of cell dispersion in the bloodstream. We previously developed methods of active induction of cells applicable to future therapeutic methods by using aggregations of bubbles containing Colon-26 cells. However, Colon-26 cells are not appropriate for therapeutic applications. Furthermore, the controllability of aggregation under ultrasound exposure has been confirmed only in still water, not in a flow. Therefore, we utilized T-cell hybridoma (CD8-OVA1.3) and induced the aggregates of bubbles and cells by using acoustic radiation force with the motion of travelling nodes. We improved our observation system including its digital camera for the active induction of aggregates containing therapeutic cells in a flow under ultrasound exposure. We found that the induction performance of bubble-surrounded cells (BSCs) was enhanced with an ultrasound frequency of 5 MHz rather than 3 or 7 MHz. Furthermore, we found that a node velocity of 5 mm/s shows the best performance compared with 1 or 10 mm/s, at which the flow velocity was 10 mm/s. We believe that the parameters realized in this study indicate effective in vivo applications in the future.