Effects of Culture Conditions on Sonoporation of Dendritic Cells

The presentation of an antigen for dendritic cells (DCs) is an important application of sonoporation to immunotherapy. To achieve efficient sonoporation of DCs, it is important to determine suitable conditions of cells (floating or adherent cells) and bubbles (phagocytosed or attached bubbles). In this study, the effects of the cell and bubble conditions on sonoporation were investigated using a high-speed camera and a confocal microscope. Two types of samples, DCs incubated on a coverslip for 0.5 h (quasi-floating cell sample) and DCs incubated for 48 h (adherent cell sample), were used to study the effects of cell conditions. Another two types of samples with different bubble conditions, phagocytosed and attached bubbles, were used to study the effects of bubble conditions. Areas of cell membrane adhesion on a coverslip scaffold, maximum expansion ratios and disappearance rates of bubbles, and membrane damage rates of cells were evaluated. The results indicated that the bubble expansion ratios and bubble disappearance rates were decreased in the condition of cells adhering to the scaffold and in the condition of bubbles being phagocytosed by DCs, resulting in decrease in a cell membrane damage rate.