(F-209) Delivery of plasmid DNA to floating cells under acoustic levitation

Introduction:: Transfection of foreign genes into cells is crucial for regulation of genes for studying cellular functions. There are various common methods including chemical, physical, and viral transfections. However, the development of a high transfection efficiency, especially in floating (non-adherent) cell lines is the universal challenge. Here, we show that the levitation technology can lead to high transfection in floating cell lines with cell viability. In addition to this, there are many aspects unique to acoustic levitation such as contactless handling of samples, which may lead to the construction of a sustainable research environment without single use plastic tips and bottles.







Materials and Methods:: Three kinds of floating cells (HL-60, PC12, and HEK293) were used in this experiment. Cell viability of static, shaken, and ultrasonically levitated cell suspensions after 4 h incubation was tested by trypan blue exclusion assay. Plasmid DNA (pLuc)/Lipofectamine 2000 complexes were transfected to each cell line for 4h, and the transfection efficiency was determined by luciferase assay.

Results, Conclusions, and Discussions:: The viability of cells after levitation maintained more than 90%, showing that acoustic levitation has no effect on cell viability. Luciferase expression in PC12 cells transfected in levitated culture was 4.8 times higher than that in static culture (Figure 1C). A similar increase in cell transfection efficiency was also observed in adherent Huh-7 cells ^[1]. HEK293 and HL-60 cells showed no significant increase in expression efficiency. In the case of Huh-7 cells, it was found that an enhancement of macropinocytosis was the leading cause of higher transfection efficiency. Therefore, we are conducting further experiments to elucidate the endocytic pathway and transfection mechanism.

We showed that cell transfection in the levitation culture resulted in higher transfection efficiency without reduction of cell viability even after 4 h of levitation, compared to that in static and shaken cultures.

Acknowledgements (Optional): :

References (Optional): : [1] T. Arai, et al., Adv. Sci. 2022, 9, 2203576