Characterization of LNPs via Density Matching AUC

Determining the purity of LNPs loaded with nucleic acids can be challenging due to their size heterogeneity. Here, we present analytical ultracentrifugation (AUC) methods that use multiwavelength and density matching with D2O. These methods allow us to measure the sedimentation and diffusion coefficient distributions of the LNPs, as well as the lipid and RNA components. Additionally, the density matching method allows us to determine their partial specific volume distributions; since the densities of the RNA and lipids are substantially different, the measured density is directly proportional to the loading of nanoparticles. Allowing for the characterization and differentiation of empty LNPS and different RNA loading states. 

 

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