Fig. 6

In vitro therapeutic efficacy of d-NPs in B16F10 cells. A, B The cytotoxicity of the free drug to B16F10 cells in traditional two-dimensional (2D) cell culture (DTX dose of treatment in 2D was 100 µg/mL, 50 µg/mL, 25 µg/mL, 12.5 µg/mL, 6.25 µg/mL) and three-dimensional (3D) tumor spheroids (DTX dose of treatment in 3D was 200 µg/mL, 100 µg/mL, 50 µg/mL, 25 µg/mL, 12.5 µg/mL, 6.25 µg/mL). C, D The cytotoxicity of nanoformulations (d-PN, d-PRN and d-PGN) to B16F10 cells in traditional 2D cell culture and 3D tumor spheroids. E IC₅₀ of free drugs and drug-loaded NPs on traditional two-dimensional (2D) cells and 3D tumor spheroids. F Cytotoxicity of B16F10 cells cotreated with rapamycin and drug-loaded NPs for 24 h. G Apoptosis of B16F10 cells after treatment with free drug and drug-loaded NPs for 24 h.