Fig. 8

Confocal microscopy images of A549 cells after 24 h exposure to GFP dissolved in ʟ-arginine (A1–A3) and GFP-doped nanoparticles C_FS_1FS_2F (B1–B3), and control cells (C). Top (1): merge-images; middle (2): Cell membrane (WGA): red; bottom (3): GFP, green. Arrows indicate internalised nanoparticles. Contrast and brightness were enhanced by using the ImageJ software