Synthesis of a non-viral vector for gene transfer via the high-affinity neurotensin receptor

We describe herein a method for synthesizing a non-viral gene vector that exploits the internalization properties of neurotensin (NT), as well as the procedures for a successful gene transfer to cells via the high-affinity NT receptor. The gene vector is NT cross-linked with poly-L-lysine via N-succinimidyl-6-[3'-(2-pyridyldithio)propionamido]hexanoate (LC-SPDP). The SPDP-derivatives containing either NT or poly-L-lysine are purified by gel filtration. The non-viral vector resulting from the reaction of NT-SPDP with HS-SPDP-poly-L-lysine is purified on Biogel A-1.5 m. This vector is complexed with plasmid DNA at a specific molar ratio to form the NT-polyplex, which ensures the delivery of the gene of interest to cells under conditions of receptor-mediated internalization. The NT-polyplex has shown ability to mediate transient gene expression in vitro [Brain Res. Mol. Brain Res. 69 (1999) 249] and in vivo [Soc. Neurosci. Abstr. 25 (1999) 67. 7]. This approach holds great promise for research and therapy.