Fig. 3

Cell uptake and tumor penetration of the four types of nanocarriers in vitro. A LSCM images showing the uptake of the four types of nanocarriers by 4T1 cells and macrophages. Blue: DAPI; red: nanocarriers. B TEM images of 4T1 cells incubated with FA-MSNR/LMDI@MP/MPCM (indicated by the arrows) for 1, 2 and 4 h. C LSCM images of 4T1 cell spheroids incubated with the four types of nanocarriers at pH 7.4 and pH 6.5. (I: FA-MSNR/LMDI@MP/MPCM; II: FA-MSNR/LMDI; III: FA-MSNR/LMDI@MPCM; IV: FA-MSN/LMDI)