(A) Cellular uptake of polyplexes in an HN12-YFP/U87 (FR-high/FR-low) co-culture model monitored by using fluorescence microscopy. Blue, DAPI; yellow, HN12-YFP cells; and red, Cy3-plasmid. (B) Relative percentages of HN12-YFP and U87 cells presenting Cy3 plasmid in the co-culture model following 6-h incubation with G4-FA/Cy3 plasmid and G4/Cy3 plasmid polyplexes.
DAPI: 4′,6-diamidino-2-phenylindole; FR: Folate receptor.