Figure 3: FACS analysis of cellular binding of micellar formulations prepared with different PEG blocks in a co-culture system. A co-culture composed of target MCF-7 cells and non-target C166-GFP cells was treated for 1h with either plain micelles or phage-micelles constructed from PEG750- PE, PEG2k-PE, or PE EG5k -PE conjugates, followed by FACS analysis of cellassociated micelles as indicated by the red fluorescence increase. The dot plots were bounded into four regions (R1, R2, R3, and R4). FL1-H (green); FL2-H (red); (A) A representative dot plot showing the untreated co-culture of MCF-7 cells and C166-GFP cells. Red dots in region R1, the location of untreated MCF-7 cells; green dots in region R2, the location of untreated C166-GFP cells; (BD) Plain micelle-treated co-culture of MCF-7 cells and C166-GFP cells. Pink dots in region R3, plain micelle-associated MCF-7 cells; blue dots in region R4, plain micelle-associated C166-GFP cells; (E-G) MCF-7-targeted phage-micelletreated co-culture of MCF-7 and C166-GFP cells.