Effect of IL-1β, TNF-α and IGF-1 on trans-endothelial passage of synthetic vectors through an in vitro vascular endothelial barrier of striated muscle.

When administrated in the blood circulation, plasmid DNA (pDNA) complexed with synthetic vectors must pass through a vascular endothelium to transfect underlying tissues. Under inflammatory condition, cytokines can modify the endothelium integrity. Here, the trans-endothelial passage (TEP) of DNA complexes including polyplexes, lipoplexes and lipopolyplexes was investigated in the presence of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β) or insulin-like growth factor-1 (IGF-1). The experiments were performed by using an in vitro model comprising a monolayer of mouse cardiac endothelial cells (MCEC) seeded on a trans-well insert and the transfection of C2C12 myoblasts cultured on the lower chamber as read out of TEP. We report that polyplexes made with a histidinylated derivative of lPEI (His-lPEI) exhibit the highest capacity (10.5 μg cm-2 h versus 0.324 μg cm-2 h) to cross TNF-α-induced inflamed endothelium model, but this positive effect is counterbalanced by the presence of IL-1β. His-lPEI polyplex TEP is also increased in the presence of IGF-1 (2.58 μg cm-2 h). TEP of lipid-based DNA complexes including lipoplexes and lipopolyplexes was lowest compared with polymer-based DNA complexes. Overall, the results indicate that under inflammation, His-lPEI polyplexes have a good profile to cross a vascular endothelium of striated muscle with low cytotoxicity and high transfection efficiency of C2C12 myoblasts. These data provide insights concerning the endothelial passage of vectors in inflammatory conditions and can serve as a basis towards in vivo studies.