Fig. 5.

Cuboplexes deliver siRNA more effectively compared to lipoplexes. (A) Uptake of siRNA in HeLa cells and 4T1 cells quantified by flow cytometry. Trypan blue (TB) was added to quench the fluorescence of siRNA outside the cellular membrane and that of membrane-compromised cells (n = 3, data presented as mean ± SD). Significance between groups was calculated with two-sided Student’s t-test and indicated as *P ≤ 0.05, **P ≤ 0.01, or ***P ≤ 0.001. (B) Schematic representation of live cell imaging experiments evaluating the internalization and siRNA endosomal entrapment of LNP–RNA complexes. (C and D) HeLa cells were treated with DiO-labeled LNP–siRNA complexes (red) and imaged every 5 min. Less lipoplexes (C) enter the cells compared to cuboplexes (D). (Scale bar, 10 μm.) (E and F) Endosome-labeled cells were treated with cuboplexes (E) and lipoplexes (F) containing AF546-siRNA and imaged every 5 min. Less siRNA (red) are entrapped in the endosome in cuboplex-treated cells compared to those treated with lipoplexes. (Scale bar, 10 μm.)