Multi-attribute analysis of nanoparticle vaccine adjuvants by Electrical Asymmetrical Flow Field-flow Fractionation...

Adjuvants play important roles in vaccine immunogenicity, potency, and clinical efficacy. Recently, nanoparticle-based adjuvants have garnered significant attention due to their unique properties, mechanisms of action and successes in vaccines against COVID-19. Understanding the size and charge of these nanoparticles can help predict and control their behavior in biological systems. Conventionally, the size and charge of nanoparticles are measured using dynamic light scattering (DLS) and electrophoretic light scattering (ELS) in batch mode. Herein, we report an electrical asymmetrical flow field-flow fractionation (EAF4) method for the multi-attribute characterization of lipid nanoparticle (LNP) and nanoemulsion (NE). The EAF4 was coupled with UV, multi-angle light scattering (MALS), DLS, electrophoretic mobility (e-mobility) and refractive index (RI) detections to measure the molecular weight (MW), hydrodynamic radius (Rh) and zeta potential (ζ) of the nanoparticles. This EAF4-UV-MALS(DLS)-RI method allows for peak-targeted analysis of size and charge properties. Nanoparticle attributes are analyzed by EAF4 method in a more specific manner than by batch DLS/ELS.