Figure 3.
Cellular uptake and tumor penetration properties of the prodrug NPs in vitro. (A) The representative CLSM images (scale bar = 10 μm), and (B) Flow cytometric plots of intracellular uptake of the PHNJ@DiL or NJ@DiL NPs in 4T1 breast tumor cells in vitro (treated at an identical DiL concentration of 5.0 μmol/L); (C) CLSM examination of tumor penetration profile of the prodrug NPs in the 3-D spheroids of 4T1 tumor upon 8 h incubation in vitro (scale bar = 50 μm); (D) Quantitative fluorescence intensity profile along the arrow region at depth of 40 μm.
