Fig. 3

SP-AH nanoparticles targeted breast cancer cells in vitro. a Dot blot analysis of HER2 receptor levels of MCF7, SKBR3 and MDA-MB-453 (MDA) breast cancer cells. Actin was used as loading control (n = 3). b Flow cytometry (FACScan) analysis of MCF7, SKBR3 and MDA cells treated with fluorescent-labeled SP-F, SP-AF, and SP-AH nanoparticles (representative analysis was shown, n = 3). Untreated cells were used as control (CNT). c Confocal microscopy images of SP-F- or SP-AH-treated MCF7, SKBR3 and MDA cells. Hoechst staining was used to mark the nuclei (blue). d Time kinetics (5 min, 1 h (h), 6 h, 24 h and 48 h) of SP-AH nanoparticle attachment and uptake in SKBR3 or MDA cells. Blue signal, Hoechst staining of nuclei. e Graph depicting the ImageJ analysis of red fluorescence intensity per cell versus time in SKBR3 and MDA cells: a.u., arbitrary fluorescence signal intensity units. f Time-dependent (1 h, 3 h and 6 h) colocalization (merge, yellow) of SP-AH nanoparticles (red) with the early endosome markerRAB5 (green). Scale bar: 25 µm