Fig. 6

NS coupled with electric field for cellular DNA transfection. (a) Components of the NSEP device. The upper PDMS chunk housing the cell culture chamber, the NS, the lower PDMS layer of the microchannel, ITO glass (bottom electrode), a Pt electrode (top electrode) are integrated into the NSEP device. (b) Photograph of NSEP device. (c) Schematic representation of transfection using NS coupled with electric field (Electric field & NS). (d, e) COMSOL simulation of electric potential distribution at the cell-NS interface. (f) Schematic representation of the 2D model used for COMSOL simulation, featuring three intercept lines marked as 1, 2, and 3 across the cell membrane. (g) The electric potential across the cell membrane along the three intercept lines. The horizontal axis, the Arc line, represents the length of the intercept line, while the corresponding Y values from 0 to 0.10 μm represent the electric potential values across the intercept lines from top to bottom as shown in (f). (h) Fluorescent microscopy images capturing GFP expression 24 h after NS coupled with electric field-mediated transfection. The images merge signals from GFP (green), Hoechst (gray), and PI (red). Upper panel: HeLa cells, middle panel: DC2.4 cells, lower panel: HL-1 cells. Rows from left to right represent different electric voltages (10, 15, 20, 25, and 30 V). Scale bars in all images measure 200 μm. (i) Quantitative assessment of transfection efficiency and cell viability following pMAX-GFP transfection via NS coupled with electric field delivery system, as determined from microscopic images. Mean ± SEM, n = 5 regions, Two-way ANOVA