*2.15. Scratch Assay*

At 24 h prior to transfection, 1 × 10<sup>5</sup> T24 and MDA-MB 231 cells per well were seeded in a 6-well plate in 2000 μL of growth medium. The medium was replaced by 800 μL fresh medium and 200 μL MSN160 nm-454-GE11 (500 μg mL−<sup>1</sup> in HEPES bu ffer) loaded with Ctrl RNA or miR200c was added. Cells were incubated with MSN160 nm-454-GE11 for 4 h, then the medium was changed. After 24 h additional incubation time, the cell layer was broken by a scratch using a 200 μL Eppendorf tip. Cells were washed with PBS and microscope (Axiovert 200, Zeiss, Oberkochen, Germany) pictures were taken after 24 h.
