Figure 5.

Quantification of intracellular doxorubicin and C6-ceramide by mass spectrometry. Cells were incubated with previously determined DXR concentrations corresponding to the lowest IC₅₀ of the [F3]L-DC₆11 formulation. SKOV-3 cells were incubated with 0.63 and 0.49 µM for 4 and 8 h, respectively, and MDA-MB-231 with 25.87 and 6.35 µM for 1 and 4 h, respectively, at 37 °C with F3 peptide-targeted liposomal DXR ([F3]L-D) or DXR:C6-ceramide combination at a molar ratio of 1:1 ([F3]L-DC₆11) or the non-targeted counterpart (L-DC₆11). DXR and C6-ceramide were quantified after extraction from the cultured cells. Data represent the mean ± SEM (n = 3; two-way ANOVA with Tukey’s multiple comparisons post-test; **** p < 0.0001).