Cationic Green Solid Lipid nanoparticles by the fatty acid coacervation method for gene delivery to the cornea: preliminary studies on cell and isolated tissue models

Gene augmentation therapy is an emerging approach to treat several corneal diseases, accounting for visual impairment and blindness worldwide. To this aim, in this preliminary experimental study, cationic Solid Lipid Nanoparticles (SLNs), obtained with the fatty acids coacervation method from natural soaps (Green SLNs), were used to prepare non-viral vectors for the green fluorescent protein encoding plasmid DNA (pDNA). Of note, Green SLNs contain oleic acid and the unsaponifiable fraction, that can act as a permeation enhancer and as an antioxidant, respectively. Stable vectors were obtained with and without the inclusion of hyaluronic acid. SLNs-based vectors were tested for pDNA binding/protection/release, and on in vitro and ex vivo corneal models for association and transfection capacity. pDNA was efficiently bound, protected and released from the vectors. In vitro studies on cell models showed a good cells association, but a poor transfection. Promising results were obtained in ex vivo transfection on rabbit corneas, in the case of vectors without hyaluronic acid, probably thanks to their oleic acid content.