Fig. 3.

In vitro bioassay results and plausible mechanism after MC-38 cells were treated with Eu-FBCP/PTX (**p < 0.01 and **p < 0.001). a Cytotoxicities of MC-38 cells treated with Eu-FBCP/PTX or Eu-s/PTX for 24 h, as well as free PTX and individual Eu-FBCP or Eu-s (n = 6). b, c FACS results (n = 3; fluorescence profile and MFI) for comparing cellular uptake between Eu-FBCP/Cy5.5 and Eu-s/Cy5.5. d, e FACS results (n = 3; fluorescence profile and MFI) for comparing cellular uptake of Eu-FBCP/Cy5.5 between the pretreatments with different inhibitors, including low-temperature conditions. f Schematic of a plausible mechanism for the uptake pathway from the pretreatment of cells with the different inhibitors and subsequent incubation with Eu-FBCP/Cy5.5