Fig. 4. (a) Fluorescence images of the MCF-7/ADR cells stained with calcein-AM incubated without/with FA-PEG-b-PAA (250 μM), PIC micelles containing different amount of WP6. (b) Fluorescence intensity changes of the culture in the presence of FA-PEG-b-PAA or PIC micelles containing different amounts of WP6. (c) Cytotoxicity of DOX·HCl (25 μM), FA-PEG-b-PAA, PIC micelles, and DOX·HCl (25 μM) loaded PIC micelles with different concentrations of WP6 against MCF-7/ADR cells. Schematic illustration of the preparation of PIC micelles and possible mechanism to inhibit the efflux pump by forming a host–guest complex WP6⊃ATP in the cell.
