Figure 6. Analysis of cationic MB stability after interaction with pDNA by flow cytometry.

MBs were prepared with a mixture of cationic lipids, pH-sensitive lipids in a molar ratio of 1:1 (MB1), 2:1 (MB2) or 1:2 (MB3) respectively and 5% of PEGylated phospholipids (DSPE-PEG5000). A complexation between 10 µl of cationic MBs and 1 µg of Cy5-labelled pDNA was made in 10 mM HEPES buffer. (A) The FSC-SSC plot of the MBs presents two different populations; MBs and lipoplexes. The MB population was gated and showed pDNA fluorescence in FL5 channel. The proportion of these MBs and lipoplexes populations have been analysed over time of complexation (B) MBs and (C) for lipoplexes.