Peptide and micelle activity in vitro. A-B) D-melittin peptide (A) and micelles (B) were incubated with human and murine tumor cells (3T3, A549, and CT26) for 24 hours, and viability was assessed via MTS assay. C-D) D-melittin peptide (C) and micelles (D) were incubated with both wild type (WT) and doxorubicin-resistant (DOX-R) MDA-MB-435 cells for 24 hours, and viability was assess via MTS assay. E-F) Hemolytic activity of peptide (E) and (F) micelles was determined against red blood cells (RBCs) at pH 5.4, 6.4, and 7.4. H) Endosomal escape of micelles was demonstrated in Gal8-GFP-RAW 264.7 macrophages (500 µm scale). Endosomal disruption is observed as green punctae, as Gal8-GFP+ binds to the inner membrane of endosomes. Image insets (red) are magnification of cells (100 µm scale).