Fig. 2

Intracellular localization of chitosan NCs. a \({\text{M}}{\upphi }{\text{s}}\) were cultured for 18 h in the presence of 100 µg/ml CS-NCs and intracellular visualization assessed by TEM. Yellow arrows: CS-NCs, Red arrows: NCs fusion. b \({\text{M}}{\upphi }{\text{s}}\) were incubated with 100 µg/ml DiD-labelled CS-NCs (green) for 18 h, co-stained with LysoTracker (red) and DAPI (blue), and visualized by confocal microscopy. c Pearson correlation coefficient between CS-NCs and acidic compartments (Lysotracker positive). Each dot represents one single cell (n = 98). Error bars represent the mean ± SD. d \({\text{M}}{\upphi }{\text{s}}\) were exposed to 100 µg/ml CS-NCs or latex beads for 18 h and incubated with Lysotracker Red. The intensity of the lysotracker staining was then quantified by FACS. Results are expressed as the mean fluorescence intensity (MFI). Significant differences between treatments and untreated controls are indicated by an asterisk, in which *p < 0.05. Error bars represent the mean ± SD