Characterization of Lipid Nanoparticles Containing Ionizable Cationic Lipids Using Design-of-Experiments Approach

Lipid nanoparticles (LNPs) containing short-interfering RNA (LNP-siRNA systems) are a promising approach for silencing disease-causing genes in hepatocytes following intravenous administration. LNP-siRNA systems generated by rapid mixing of lipids ethanol with siRNA aqueous buffer (pH 4.0) where the ionizable lipid is positively charged, followed dialysis to remove and raise pH 7.4. Ionizable cationic critical excipient LNP as they drive entrapment intracellular delivery. A recent study on formation suggested that segregate from other components upon charge neutralization form an amorphous oil droplet core LNPs. This leads decrease intervesicle electrostatic repulsion, thereby engendering fusion small vesicles final LNPs increased size. In this study, we prepared four (hydrogenated soy phosphatidylcholine, cholesterol, PEG-lipid, 1,2-dioleoyl-3-dimethylammonium propane) microfluidic mixing. The effects preparation parameters [lipid concentration, flow rate ratio (FRR), total rate], process, complex between physicochemical properties [siRNA particle size polydispersity index (PDI)] were investigated using design experiments approach. results showed no impact encapsulation, but concentration FRR significantly affected PDI. addition, effect was suppressed presence anionic polymers such compared case alone. More intriguingly, unlike empty LNPs, PDI increase occurred after systems. Such changes at = 1. These findings provide useful information guide development manufacturing conditions