The exhibition of polyethylene imine/DNA coated with oligonucleotides for gene delivery

The application of technique of assembling oligonucleotides (5´-C₁₀A₂₀-3´) with binay polyethylene imine (PEI)/DNA complexes used to prepare a ternary anioic gene delivery system. Characterization of PEI/DNA/oligonucleotide complexes demonstrated that nanoparticles possessed the negative surface charge -50 mV and size of around 100-170 nm when the molar ratio of oligonucleotide/PEI exceeded 9. Compared with PEI/DNA complexes PEI/DNA/oligonucleotide complexes could completely resistant against erythrocyte agglutination because of anionic surface charge and would not disassociate during the process of forming ternary complexes. The oligonucleotide-coated PEI/DNA complexes exhibited high gene expression with low cytotoxicity in the living Hs68 cells (cell line) and fibroblast-like synoviocytes (primary cells), respectively. Additionally, the deposition of a layer of oligonucleotide onto the binary PEI/DNA complexes could prevent serum inhibition during transfection process. Therefore, the oligonucleotide-coated PEI/DNA complex seems to be a feasible approach to develop new anionic gene delivery systems.