Fig. 4

CLSM images of P727 isolate cells stained by SYTO 9 (green) and PI (red) as well as TEM images of P727 isolate cells. The P727 isolate cells were separately incubated with culture medium (negative control), blank NPs (without MXF-loaded Oxi-αCD NPs), MXF, MXF/Oxi-αCD NPs, and MXF/FA-Oxi-αCD NPs at 1/4 × MIC of MXF (4 μg/mL) for 4 h, then were stained by a dye mixture (SYTO 9 dye and PI at a ratio of 1:1) for 15 min for CLSM observation. As for TEM observation, the P727 isolate cells were fixed with 2.5% glutaraldehyde overnight. The red arrow indicates that P727 isolate cells had complete cellular surface disruption and the cellular cytoplasmic content of these cells underwent massive outflow, and only the cell membrane fragments remained. Scale bar represents 20 μm for CLSM images and 500 nm for TEM images