*2.2. Murine Malignant Melanoma Cells*

Murine malignant melanoma B16-F10 cells (ATCC CRL-6475) were grown in Iscove's Modified Dulbecco's Medium (IMDM; P04-20350; Panbiotech; Aidenbach, Germany) supplemented with 10% fetal bovine serum (FBS; 26140079; Fisher Scientific; Waltham, MA, USA) and antibiotics. Cells were incubated under 37 ◦C with an atmosphere of 5% CO2. B16-F10 cells were treated at a final concentration of 2 µg/mL of DOX-loaded SLPs (SLPs-DOX) for 2, 16, or 48 h. For confocal fluorescence imaging purposes, cells were fixed with 4% paraformaldehyde (43368; Alfa Aesar; Haverhill, MA, USA) and were immunolabeled with the anti-α-tubulin (B512; Sigma; Germany) antibody to recognize the microtubules. A secondary goat anti-mouse 647 (A21236; Invitrogen; USA) was used. Fluorescent images were obtained with a Nikon A1R confocal microscope (Tokyo, Japan). All images were pseudocolored.
