Fig. 6

Effect of vibrational loading on polyplex uptake and transgene expression. a Fold-increase in pDNA uptake by polyfected vs. vibropolyfected L929 cells. Experiments were carried out with lPEI/pGLuc following the post-delivery set-up. Results express the fold-increase in the amount of intracellular pDNA (t = 24 hrs) in vibropolyfected cells with respect to polyfected counterparts. Results are expressed as mean ± SD (n = 3). b Expression levels of Gaussia luciferase transcripts in L929 cells polyfected and vibropolyfected with lPEI/pGLuc. Target luciferase transcript levels were normalized to GAPDH levels. Results are expressed as mean ± SD (n = 3). c Uptake kinetics of lPEI/pDNA-FITC polyplexes. CLSM images of L929 cells transfected according to standard transfection vs. vibropolyfection (post-delivery set-up, 1,000 Hz-vibrational loading for 5 min). Cells were next fixed and imaged at 30 min, 1 hr, and 4 hrs post-polyplex addition to the cells. High-magnification (insets of c, right panels) digital images of single cells were taken 4 hrs after polyfection or vibropolyfection (post-delivery set-up, 1,000 Hz-vibrational loading for 5 min). Polyplexes are in green, while F-actin and nuclei are in red and blue, respectively. Scale bars = 50 µm and 12.5 µm (right panels)