Fig. 4.

Cell association and internalization of DNA as a function of peptide content. Peptide–lipoplexes containing radiolabeled DNA were immobilized to tissue-culture polystyrene prior to the addition of NIH/3T3 cells. Cell-associated plasmids (A) and internalized plasmid copies (B) are reported per cell. Internalization efficiency (C) was calculated as the percentage of cell-associated plasmids that are internalized per cell. Data are presented as the mean of triplicate measurements ± standard deviation. A statistical significance with p<0.05 is denoted for values with different letters.