Targeted Delivery of Complexes of Biotin–PEG–Polyethylenimine and NF-κB Decoys to Brain-derived Endothelial Cells in Vitro

Abstract

To evaluate the effect of re-directing the uptake mechanism of polyplexes containing oligodeoxynucleotide (ODN) decoys to nuclear factor kappa B (NF-kappaB) from absorptive-mediated to receptor-mediated endocytosis. Complexes of ODNs and a co-polymer of biotin-polyethylenglycol and polyethylenimine (BPP) were targeted to brain-derived endothelial cells with a conjugate of antibody 8D3 and streptavidin (8D3SA). Size and stability of ODN/BPP complexes was measured by dynamic light scattering. Cellular uptake was studied by confocal microscopy. Cell viability and pharmacological effects were investigated on murine bEnd5 cells stimulated with tumor necrosis factor. ODN/BPP complexes showed sizes of 116+/-2.3 nm, which increased by 40 nm when coupled to 8D3SA, and were stable in physiological fluids. Targeted complexes were internalized intact into endosomal compartments. Treatment conditions, which yielded significant inhibitory effects on mRNA expression of VCAM-1, ICAM-1, IkappaBalpha and iNOS by bEnd5 cells, did not affect viability. At 0.5 microM, decoy ODN significantly inhibited monocyte adhesion to bEnd5 monolayers when delivered as 8D3SA-targeted complex, while higher concentrations of untargeted complex were ineffective. The complex of NF-kappaB decoys and BPP, which can be targeted to transferrin receptors, is a promising drug candidate for neuroinflammatory diseases affecting the blood-brain barrier.