FIGURE 7.

Effect of exogenous GAGs on the cellular association and internalization efficiency at 4 °C of R₁₆ and K₁₆ polyplexes. R₁₆ (A) and K₁₆ (B) polyplexes containing FITC-labeled plasmid DNA were treated with HS and CS at 0.5:1 GAG:peptide w/w. Complexes were added to CHO-K1 and pgsA-745 cells and incubated for 1 h at 4 °C. To measure the cellular association efficiency (black bars), cells were washed with ice-cold PBS, removed non-enzymatically, and resuspended in PBS for flow cytometry analysis. To compare the internalized polyplexes (gray bars), cells were washed with ice-cold PBS containing 1 mg/ml heparin and then with 0.4% trypan blue in PBS. Cells were collected by trypsinization and analyzed by flow cytometry. Values are given as the mean ± S.D.