Fig. 4

NS coupled with mechanical force applied to cellular DNA transfection. (a) Schematic illustrating the transfection by NS coupled with mechanical force (Mechanical force & NS). (b) Depiction of the procedure involved in applying mechanical forces to the NS to facilitate transfection efficiency. (c) Fluorescent microscopy images showing the cell condition to mechanical forces applied to the NS over a 12-h period. The images display the merged signals from Calcein AM (green), Hoechst (gray), and PI (red). The upper panel represents HeLa cells, the middle panel shows DC2.4 cells, and the lower panel features HL-1 cells. Results of cell condition after different weights (0.1, 0.2, 0.5, and 1.0 g) application are presented in rows from left to right. (d) Assessment of cell viability under different mechanical force conditions based on microscopic images. Mean ± SEM, n = 3, One-way ANOVA. (e) Fluorescent microscopy images displaying cells expressing GFP following delivery via NS coupled with mechanical force. These images represent the merged signals of GFP, Hoechst, and PI, with the rows corresponding to those in panel (c). (f) Evaluation of transfection efficiency and cell viability after pMAX-GFP transfection mediated by NS coupled with mechanical force, based on the microscopic images. Mean ± SEM, n = 3, Two-way ANOVA. Scale bars in all images are 200 μm