Figure 1.

Polyplex characterization

The sequence-defined cationic lipo-OAA containing an N-terminal azido group complexed NIS pDNA (N/P ratio of 12) to build an azido bearing core (A). Structures are shown of PEGylated DBCO agents containing the GE11 peptide to target tumoral EGFR or TfRre peptide to target transferrin receptors (B). Ligands were added with 0.25 equiv to build EGFR mono-targeted (C) or TfR mono-targeted polyplexes (D). For dual-targeted polyplexes, 0.125 equiv of DBCO-PEG₂₄-GE11 and 0.125 equiv of DBCO-PEG₂₄-TfRre were used (E). TEM images are shown of DBCO-PEG₂₄-Dual/NIS (F), DBCO-PEG₂₄-GE11/NIS (G) and DBCO-PEG₂₄-TfRre/NIS polyplexes (H) revealing spherical shapes and narrow size distribution. One representative image of each group is shown (scale bar, 200 μm; close-up, 80 μm). TEM measurements revealed a size of 25–32 nm and DLS measurements a size of 42–48 nm (size by numbers) with a uniform size distribution (PDI ≤ 0.3) (I) and a positive surface charge below 20 mV (J) (∗p ≤ 0.05, ∗∗∗p ≤ 0.001). Results are reported as mean ± SEM (n = 3).