Structural differences in mRNA lipid nanoparticle groups linked to how they carry cargo and enter cells

Microfluidic formulation results in structurally diverse lipid nanoparticles with varying mRNA loading, affecting transfection efficiency.

• Lipid nanoparticles display significant heterogeneity in size, shape, and cargo loading due to non-equilibrium assemblies.
• Asymmetric flow field-flow fractionation combined with other techniques provides detailed structural models of mRNA-loaded nanoparticles.
• Spheroidal geometries contain densely packed mRNA cores, while bleb-like morphologies show reduced mRNA content with segregated lipid domains.
• The N/P ratio influences cargo distribution, with N/P=6 yielding a more uniform mRNA copy number across different nanoparticle subpopulations.
• Higher transfection efficiency is associated with the N/P=6 formulation, emphasizing the role of core organization and loading homogeneity.

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