Nucleic Acid Delivery by Solid Lipid Nanoparticles Containing Switchable Lipids: Plasmid DNA vs. Messenger RNA.

The development of safe and effective nucleic acid delivery systems remains a challenge, with solid lipid nanoparticle (SLN)-based vectors as one of the most studied systems. In this work, different SLNs were developed, by combination of cationic and ionizable lipids, for delivery of mRNA and pDNA. The influence of formulation factors on transfection efficacy, protein expression and intracellular disposition of the nucleic acid was evaluated in human retinal pigment epithelial cells (ARPE-19) and human embryonic kidney cells (HEK-293). A long-term stability study of the vectors was also performed. The mRNA formulations induced a higher percentage of transfected cells than those containing pDNA, mainly in ARPE-19 cells; however, the pDNA formulations induced a greater protein production per cell in this cell line. Protein production was conditioned by energy-dependent or independent entry mechanisms, depending on the cell line, SLN composition and kind of nucleic acid delivered. Vectors containing 1,2-dioleoyl-3-trimethylammonium-propane (DOTAP) as unique cationic lipid showed better stability after seven months, which improved with the addition of a polysaccharide to the vectors. Transfection efficacy and long-term stability of mRNA vectors were more influenced by formulation-related factors than those containing pDNA; in particular, the SLNs containing only DOTAP were the most promising formulations for nucleic acid delivery.

Gene delivery in the cornea: in vitro & ex vivo evaluation of solid lipid nanoparticle-based vectors.

AIM: Inflammation is a process that underlies sight-threatening ocular surface diseases, and gene supplementation with the plasmid that encodes for p-IL10 will allow the sustained de novo synthesis of the cytokine to occur in corneal cells, and provide a long-term anti-inflammatory effect. This work describes the development of solid lipid nanoparticle systems for the delivery of p-IL10 to transfect the cornea. RESULTS: In vitro, vectors showed suitable features as nonviral vectors (size, Î¶-potential, DNA binding, protection and release), and they were able to enter and transfect human corneal epithelial cells. Ex vivo, the vectors were found to transfect the epithelium, the stroma and the endothelium in rabbit corneal explants. Distribution of gene expression within the cell layers of the cornea depended on the composition of the four vectors evaluated. CONCLUSION: Solid lipid nanoparticle-based vectors are promising gene delivery systems for corneal diseases, including inflammation.

Nanopartículas sólidas lipídicas para terapia génica / Solid lipid nanoparticles for gene therapy

La terapia génica consiste en la administración de ácidos nucleicos con el fin de modular la expresión de proteínas específicas y revertir así una enfermedad. Es una nueva área de la medicina con gran potencial para el tratamiento de enfermedades tanto hereditarias como adquiridas. Hasta ahora, los sistemas virales de administración de ácidos nucleicos han resultado eficaces, pero presentan importantes problemas de seguridad. Los vectores no virales, en cambio, son más seguros pero menos eficaces, aunque su eficacia ha aumentado significativamente en los últimos años. Esta revisión recoge la contribución de nuestro grupo de investigación al diseño de vectores no virales basados en nanopartículas sólidas lipídicas (SLNs) para terapia génica. Hemos estudiado la relación entre factores de la formulación con los procesos de internalización y disposición intracelular del material genético, que condicionan la eficacia de transfección, y por primera vez demostramos la capacidad de las SLNs para inducir la síntesis de una proteína tras su administración endovenosa a ratones. Esta revisión también recoge nuestros trabajos sobre la aplicación de las SLNs en el tratamiento de enfermedades infecciosas y enfermedades raras, como la retinosquisis juvenil ligada al cromosoma X, enfermedad en la que la retina está desestructurada debido a la deficiencia de la proteína retinosquisina. La administración de SLNs con el gen que codifica esta proteína en un modelo animal de esta enfermedad indujo la recuperación estructural de la retina. Los trabajos aquí recogidos muestran el gran potencial de las SLNs como sistemas de administración de ácidos nucleicos (AU)

Gene therapy is a rapidly advancing field with great potential for the treatment of genetic and acquired systemic diseases. This therapy requires the introduction of foreign genetic material in the target cells to modify a genetic sequence. Viral vectors are the most effective, but their application is limited by their immunogenicity, oncogenicity and the small size of the DNA they can transport. Non-viral vectors, however, are safer, lowered cost, and more reproducible and do not present DNA size limit. The main problem of nonviral systems is their low transfection efficiency, although it has improved during the last years. This review presents the contribution of our research group to the design and evaluation of SLNs based non-viral vectors for gene transfer. We report our studies about the relationship between formulation factors and cell uptake and intracellular trafficking of the genetic material, very important for transfection. We have shown, for the first time, the ability to induce transgene protein expression of the SLNs after endovenous administration to mice. This revision also reports our work about the potential application of SLNs to the treatment of infectious and rare diseases, as the X-linked juvenile retinoschisis, a retinal disorder due to a deficiency in the protein retinoschisin, and characterized by poor eyesight and degeneration of the retina. The intraocular injection of SLNs bearing the gene that encodes retinoschisin to diseased mice led to the partial recovery of the retina. All together, our results show the potential of SLNs as a system for gene delivery (AU)