Phat Dinh / Chemistry & Biochemistry / Faculty Mentor: Kevin Schug
Lipid nanoparticles (LNPs) encapsulate therapeutic nucleotides to protect their labile structure and facilitate cellular uptake. Conventionally, dynamic light scattering (DLS) is used to determine average LNP size and size distribution. The main drawback of DLS is that it is a batch analytical technique, limiting its effectiveness for highly polydisperse samples or those with multiple size populations. For these more heterogeneous samples, separations are required prior to size determination. Size exclusion chromatography (SEC) is often used to combat this shortcoming. However, the analysis of LNPs on commercial SEC columns is not ideal due to insufficient pore sizes, shear forces, and over-adsorption of LNPs onto the stationary phases. In this study, spongy monoliths were modified with polyethyleneimine (PEI), and reaction conditions were optimized, including PEI molecular weight, pH, reaction time, and the addition of a cross-linking step. Optimized conditions demonstrated a reduction in LNP over-adsorption, with the amount of sample required to saturate the monolith reduced to 40 μL, compared to 400 μL used for an SEC column. Two distinct distributions of LNPs were also selectively separated, with the later-eluting distribution possessing four times more cholesterol than the earlier-eluting one.
Leave a Reply