Alternative Structural Lipids Impact mRNA-Lipid Nanoparticle Morphology, Stability, and Activity.

Area of Science:

• Biotechnology
• Materials Science
• Nanotechnology

Background:

• Lipid nanoparticles (LNPs) are essential for delivering messenger RNA (mRNA) into cells for therapeutic and vaccine applications.
• The structural composition of mRNA-LNPs significantly influences their delivery efficiency and protein production capabilities.

Purpose of the Study:

• To investigate the impact of alternative structural lipids on mRNA-LNP physicochemical properties, morphology, stability, and in vitro activity.
• To explore glyceryl monooleate and phytantriol as replacements for traditional phospholipids in mRNA-LNPs.

Main Methods:

• Physicochemical characterization of mRNA-LNPs including particle size, mRNA encapsulation, and integrity.
• Morphological analysis using synchrotron small-angle X-ray scattering, pulsed gradient stimulated echo proton nuclear magnetic resonance, and cryogenic-transmission electron microscopy.
• In vitro assessment of transfection and cytokine stimulation in HeLa cells and human blood.

Main Results:

• Alternative structural lipids induced diverse mesophases in mRNA-LNPs, dependent on lipid type and molar ratio.
• Specific lipid combinations resulted in distinct quality attributes, enhanced stability (hexagonal and cubic phases up to 6 and 3 months, respectively), and varied in vitro activities.
• Novel mRNA-LNPs demonstrated reduced immunostimulatory cytokine production.

Conclusions:

• The composition of structural lipids critically influences mRNA-LNP structure, stability, and biological activity.
• Alternative lipids offer a promising strategy for developing more stable and less immunogenic mRNA delivery systems.
• These findings pave the way for advanced mRNA-based therapeutics and vaccines.