Figure 6. The effect of the degradation of the N-terminus of the phage fusion protein by proteinase K (PK) on the binding of rhodamine-labeled, MCF-7-specific phage-liposomes to target MCF-7 cells.

(A) Representative FACS histograms, and (B) geomean analysis showing that PK treatment results in a significant decrease in MCF-7 cell-associated MCF-7-specific phage-liposomes to a level comparable statistically to that of plain liposomes. (C) Representative FACS histogram and (D) geomean analysis showing that PK treatment has no effect on MCF-7 cell-associated plain liposomes. Red: Untreated cells; Blue: Plain liposomes; Pink: Phage- liposomes; Green: Phage-liposomes with PK treatment. Yellow: Plain liposomes with PK treatment. (E) Fluorescence photometric data confirming that PK treatment results in a decrease in MCF-7 cell-associated MCF-7-specific phage–liposomes to the level comparable to plain liposomes, but has no effect on MCF-7-associated plain liposomes. Grey bar: MCF-7-phage-liposomes; Brocade bar: Phage-liposomes with PK treatment. White bar: plain liposomes; Black bar: Plain liposomes with PK treatment. (F) The quantity of MCF-7 cell-associated MCF-7- specific phage–liposomes decreases with an increase in the PK concentration. (Mean ± SD, n=3).