Fig. 6.

dPEI polyplexes transfect human mucosal epithelial cells and can facilitate transfection of stromal cells. Human penile glans tissue, cut into 3 mm × 3 mm explants was transfected with GFP expressing plasmid complexed to dPEI. Negative control tissue stained with DAPI and Wheat Germ Agglutinin (WGA) (A), MHC Class II (HLA-DR) expression (B) and GFP expression (C and D) was examined 48 h post transfection using a fluorescent microscope. Mucosal epithelium is indicated by the white dotted lines while GFP expressing cells (green) are indicated by red arrows. Transwell inserts containing apically cultured confluent monolayers of Caco-2 cells were transfected with dPEI-GFP polyplexes (E). After 4 h, the media in the basal chamber were removed and added to CHO cells to evaluate polyplex migration through mucosal epithelium (F). Negative control Caco-2 cells grown on transwell inserts (G). Transepithelial electrical resistance (TEER) was monitored for 4 h following application of 0–5 μg dPEI-GFP polyplexes (H). Luciferase expression from dPEI transfected cells is expressed as relative light units (RLU) for apical Caco-2 (I) and basolateral CHO (J) cell lines.