Figure 4.
The mechanisms of cellular uptake. (A) Cellular uptake of PPNs and EXOs in E12 cells (with post-removal of mucus) and Caco-2 cells. ∗∗P < 0.01 versus PPN. (B) CLSM images of DiO-loaded PPNs or EXOs treated Caco-2 cells. Blue: nucleus. Scale bar: 10 μm. (C, E, F) Cellular uptake of EXO@DiI with the addition of different inhibitors. Glu: glucose; Fru: fructose. HSA: human serum albumin. ∗P < 0.05, ∗∗P < 0.01, ∗∗∗P < 0.001, versus control. #P < 0.05, ###P < 0.001. Error bars represent SD (n = 3). (D) TEM images of Caco-2 cells with or without EXOs treatment. EXOs that interacted with cell membrane and internalized EXOs were indicated by red arrows. Scale bar: 500 nm.