Cationic solid lipid nanoparticles complexed with genetic material for liver tumor treatment

Concept Gene therapy is a growing field of medicine with great potential for the treatment of several diseases and it is based on the delivery of nucleic acids (DNA, RNA, etc.,) to specific cells. To achieve their therapeutic effects, the nucleic acids need to cross several biological barriers and be protected from the degradation by nucleases, present in biological fluids and intracellular compartments, to successfully gain access to their intracellular targets. To overcome these hurdles, it is necessary to deliver the genetic material with biocompatible carriers able to facilitate its translocation across the cell membranes and protect it from being degraded while circulating in the bloodstream. At this purpose, viral and non-viral vectors have been used. Viral vectors usually have high transfection efficiencies, although there are several concerns about their use in human therapy such as an increased immune response, the possible recombination of oncogenes and the difficulty in scale-up. For these reasons, non-viral vectors have emerged as promising carriers due to their reduced immune response, low toxicity and their safety in comparison to viral vectors. Within this field, the use of solid lipid nanoparticles (SLN), made up of biocompatible and biodegradable lipids, solid at room and body temperatures, is of particular importance [1,2]. Motivations and Objectives In the present study, we aimed to develop cationic solid lipid nanoparticles able to efficiently bind, protect and deliver nucleic acids for the treatment of hepatocellular carcinoma. These nanosystems were designed in order to get features that made them suitable for parenteral administration (size, surface charge and hemocompatibility). We studied their potential as gene delivery systems carrying out biological assays (cytotoxicity, transfection, protection of the genetic material by DNasi degradation) on human hepatocellular carcinoma Hep3B cells. Results and Discussion Two different nanosystems were prepared, characterized in terms of size, polydipersity index and zeta potential, and complexed with siRNA and a DNA plasmid using different weight ratios. The physical binding between SLN and the nucleic acids was confirmed by Dynamic Light Scattering measurements and electrophoretic mobility studies. We also verified the acceptability of prepared formulations for parenteral administration performing hemocompatibility assays on human herytrocytes. Finally, in vitro biological characterization confirmed that these nanosystems are not toxic and able to protect and efficiently transfect genetic material to Hep3B cells.