A novel formulation based on 2,3-di(tetradecyloxy)propan-1-amine cationic lipid combined with polysorbate 80 for efficient gene delivery to the retina.

PURPOSE: The aim of the present study was to evaluate the potential application of a novel formulation based on a synthesized cationic lipid 2,3-di(tetradecyloxy)propan-1-amine, combined with polysorbate 80 to deliver the pCMS-EGFP plasmid into the rat retina.
METHODS: We elaborated lipoplexes by mixing the formulation containing the cationic lipid and the polysorbate 80 with the plasmid at different cationic lipid/DNA ratios (w/w). Resulted lipoplexes were characterized in terms of size, charge, and capacity to condense, protect and release the DNA. In vitro transfection studies were performed in HEK-293 and ARPE-19 cells. Formulations were also tested in vivo by monitoring the expression of the EGFP after intravitreal and subretinal injections in rat eyes.
RESULTS: At 2/1 cationic lipid/DNA mass ratio, the resulted lipoplexes had 200 nm of hydrodynamic diameter; were positive charged, spherical, protected DNA against enzymatic digestion and transfected efficiently HEK-293 and ARPE-19 cultured cells exhibiting lower cytotoxicity than LipofectamineTM 2000. Subretinal administrations transfected mainly photoreceptors and retinal pigment epithelial cells; whereas intravitreal injections produced a more uniform distribution of transfection through the inner part of the retina.
CONCLUSIONS: These results hold great expectations for other gene delivery formulations based on this cationic lipid for retinal gene therapy purposes.