Electrokinetic intracellular delivery combined with vibration-assisted cell membrane perforation

The introduction of biological macromolecules such as DNA, RNA, and proteins into living cells plays a crucial role in the fundamental analysis of cellular functions and mechanisms in living systems. Therefore, we have been developing an effective platform for the in vitro manipulation and analysis of biological cells at the single-cells. In this paper, we successfully demonstrated a novel intracellular delivery method of DNA into living HeLa cells via a glass micropipette based on DC-biased AC electrokinetically driven flow. We also proposed a vibration-assisted insertion method for penetrating a cell membrane to reduce cell damage. Preliminary insertion tests on homemade SICM system and FEM simulations revealed that the application of the mechanical oscillation can reduce the deformation of cells probably due to an increase in their viscous resistance. Moreover, we also found that a change in the ion current during the insertion process allows us to detect the instant when the micropipette tip penetrates the cell membrane.