Fig. 4

a Representative fluorescence images of the gastrointestinal tracts of the mice excised at 2, 6, 12 and 24 h after oral administrations with Cy5-labeled free EXE, DIS NPs and COM NPs; fluorescence intensities of b stomach, c duodenum, d jejunum, e ileum, and f cecum and colon of the mice after the oral administrations (n = 3), *P < 0.05 compared with free EXE group. g CLSM images of the jejunum and ileum sections of the mice excised after 2 h oral administrations with fluorescence-labeled free EXE, DIS NPs and COM NPs; the cell nuclei were stained with DAPI