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Messenger RNA lipid nanoparticles (mRNA-LNPs) have transformed the field of nucleic acid therapeutics, enabling powerful new approaches in vaccines, gene therapy, and protein replacement technologies. Despite their clinical success, the fundamental relationships between nanoparticle structure, physicochemical properties, and biological function remain poorly understood. Our lab focuses on uncovering these structure-property-function relationships to guide the rational design of next-generation mRNA delivery systems. We investigate how nanoscale organization within mRNA-LNPs influences key performance metrics such as stability, endosomal escape, and transfection efficiency.
Our research explores how formulation variables, including lipid composition, cargo type and loading, buffer chemistry, pH, storage conditions, shape the internal architecture and dynamics of mRNA-LNPs. We are particularly interested in understanding how lipid packing, mRNA-lipid interactions, and phase behavior govern nanoparticle performance under both fresh and frozen storage conditions. To study these systems, we integrate advanced biophysical and structural characterization tools such as small-angle X-ray scattering (SAXS), cryogenic electron microscopy (cryo-EM), and functional delivery assays. We also employ DENSS (DENsity from Solution Scattering) reconstruction methods to generate three-dimensional electron density maps directly from SAXS data, enabling visualization of nanoscale structural features in mRNA-LNPs. By connecting molecular organization to biological outcomes, our goal is to establish mechanistic design principles for more stable, efficient, and clinically translatable mRNA-LNP technologies.
mRNA segregation in blebs
Bleb formation as a structural feature of LNPs: We observe mRNA-loaded bleb formation in LNPs under specific formulation buffer type and concentration, reflecting localized membrane remodeling and heterogeneous organization within the particle architecture.
Relevance to LNP stability and performance: Bleb formation can influence membrane packing, structural integrity, and cargo organization, making it an important feature for understanding LNP stability, formulation robustness, and ultimately their delivery performance.
Internal ordering during endosomal acidification
Low-pH-driven inverse hexagonal phase formation in LNPs: Using SAXS and cryo-TEM, we observe the formation of an inverted hexagonal (HII) phase in lipid nanoparticles under acidic conditions, revealing a pH-dependent structural reorganization of the lipid membrane.
Implications for endosomal escape: The HII phase is associated with increased membrane fusogenicity, suggesting that this ordered structure may promote interactions with endosomal membranes and provide important mechanistic insight into how LNPs achieve endosomal escape and intracellular cargo delivery.