Ternary complexes with core-shell bilayer for double level targeted gene delivery: in vitro and in vivo evaluation

Hyaluronic acid (HA)/polyethyleneimine-dexamethasone (PEI-Dex)/DNA ternary complexes with "core-shell" bilayer were developed for double level targeted gene delivery. A PEI1800-Dex, as a core, was applied to compact DNA into a nano-sized structure and facilitate the nuclear translocation of DNA after endocytosis into tumor cells, and a polyanion HA, as the outer corona, was employed to improve targeted tumor delivery and reduce cytotoxicity.

PEI-Dex was synthesized and characterized by (1)H NMR. The characterizations of ternary complexes were investigated. Their biological properties, including transfection efficiency, cytotoxicity, cellular uptake and in vivo efficacy were evaluated systemically.

Ternary complexes with the size of about 160 nm exhibited the lowest cytotoxicity and the highest transfection efficiency in B16F10 cells among investigated complexes. The sub-cellular localization study confirmed that ternary complexes could facilitate more efficient cell uptake and nuclear transport of DNA than binary complexes. Moreover, Cy7-labeled ternary complexes obviously accumulated in the tumor after i.v. administration, indicating that ternary complexes could assist the DNA targeting to the tumor. In in vivo studies, HA/PEI1800-Dex/DNA ternary complexes showed confirmed anti-inflammation activity, and could significantly suppress tumor growth of tumor-bearing nude mice.

HA/PEI-Dex/DNA ternary complexes might be a promising targeted gene delivery system.