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

Area of Science:

• Biotechnology and Biomedical Engineering
• Nanotechnology for Drug Delivery
• Gene Therapy and Nucleic Acid Therapeutics

Background:

• Developing safe and effective nucleic acid delivery systems is crucial for gene therapy.
• Solid lipid nanoparticles (SLNs) are extensively studied vectors for nucleic acid delivery.
• Optimizing SLN formulations is key to enhancing transfection efficacy and protein expression.

Purpose of the Study:

• To develop and evaluate novel SLN-based vectors for messenger RNA (mRNA) and plasmid DNA (pDNA) delivery.
• To investigate the impact of formulation factors on transfection, protein expression, and intracellular disposition.
• To assess the long-term stability of developed SLN vectors.

Main Methods:

• Formulation of various SLNs using combinations of cationic and ionizable lipids.
• Evaluation of transfection efficacy, protein expression, and intracellular nucleic acid disposition in ARPE-19 and HEK-293 cells.
• Long-term stability studies of the SLN vectors over seven months.

Main Results:

• mRNA formulations achieved higher transfection rates than pDNA formulations, especially in ARPE-19 cells.
• pDNA formulations resulted in greater protein production per cell in ARPE-19 cells.
• SLNs containing DOTAP (1,2-dioleoyl-3-trimethylammonium-propane) exhibited enhanced stability, further improved by polysaccharide addition.

Conclusions:

• SLN formulation significantly influences transfection efficacy, protein expression, and intracellular nucleic acid behavior.
• DOTAP-containing SLNs, particularly those with polysaccharides, are promising for stable nucleic acid delivery.
• mRNA delivery via SLNs is more sensitive to formulation variables than pDNA delivery, with DOTAP-only SLNs showing high potential.