Figure 2.

ONV Intestinal Biodistribution and Cellular Absorption

(A) Quantification of PKH67 fluorescence in IBs after ONV treatment (5 μg/mL, 3 h). Cells were trypsinated and PKH67 fluorescent cells were sorted by flow cytometry. Data are presented as mean PKH67 fluorescence intensity ± SEM (n = 3). ∗p < 0.05 (Student’s t test, versus untreated IBs). (B) Representative images of Caco-2 cells treated with 10 μg of PKH67-labeled ONVs, 3 h post-treatment. Cell nuclei were labeled with Hoechst 33258. (C) Caco-2 cells were pre-treated with inhibitors of endocytosis and treated with PKH26-labeled ONVs. Fluorescence intensities of either PKH26 or Hoechst 33258 were quantified with a Cytation 3 cell imaging reader. Data are mean ratios of fluorescence intensities (PKH26/Hoechst 33258; n = 4 replicates). (D) IVIS images, 6 h post-gavage with 100 μg of DIR-labeled ONVs. (E) In vivo biodistribution of the fluorescence from DIR-ONVs in the digestive tract of SD mice 6 h post-gavage, normalized to background (n = 3 PBS-DIR as control background of DIR fluorescence, and n = 4 DIR-labeled ONV gavaged mice).