Figure 4.

Effect of I₆P₇-Stp-His/DNA NPs on BBB-Penetrating Efficiency and Cascade-Targeting Expression in U87 Cells

(A) Schematic illustration of the in vitro BBB model (a) and the b.End3/U87 cell co-culture model (b). (B and C) The apparent permeability (B) and cumulative transport amount (C) of different NPs across BBB monolayer at various incubation times. DNA was pre-labeled by YOYO-3. (D) Luciferase expression levels of different NPs in U87 cells after transporting across the BBB. Results are presented as mean ± SD (n = 3). **p < 0.01; ***p < 0.001. (E) Immunofluorescence images of glioma sections from glioma-bearing mice injected with I₆P₇scr-Stp-His/pRFP and I₆P₇-Stp-His/pRFP NPs. Red represents red fluorescent protein (RFP); green represents anti-CD31-labeled brain capillary; blue represents DAPI-labeled cell nuclei. White arrows: co-localization of RFP and brain capillary. Scale bars, 100 μm.