POS4-0690
Neck Angle-Dependent Formation of Nucleic Acid-Loaded Lipid Nanoparticles in Toroidal Ring Micromixers
Topic
S4. Colloids, Interfaces, and Molecular Assemblies for Functional Soft Materials
When and Where
Sep 29, 2026
08:30 - 09:30
Room 301 (Grand Ballroom)
Session Chairs
Hae Jung SON
Boseok KANG
Presenter(s)
Jiwoo Choi (Dankook University)
Co-Author(s)
Abstract
Lipid nanoparticles (LNPs) have emerged as key carriers for nucleic acid therapeutics such as mRNA, siRNA, and DNA. Their delivery performance is determined by lipid composition and critical quality attributes, including particle size, polydispersity index (PDI), encapsulation efficiency, and stability at physiological pH. LNPs form through rapid mixing of an organic lipid phase and an aqueous nucleic acid phase, where ethanol dilution, polarity changes, self-assembly, and nucleic acid complexation occur within a short time scale. Thus, even with the same formulation, the mixing environment generated by the mixer can significantly influence particle formation and final properties. Although high-flow mixers are frequently used for scale-up production, small-volume microfluidic platforms are useful for early formulation optimization and screening. In this study, nucleic acid-loaded LNPs were prepared using toroidal ring micromixers with different neck angles, and the effect of neck angle was evaluated at a fixed flow rate. The neck angle was considered a geometric parameter that can modulate mixing within the toroidal ring structure. The prepared LNPs were characterized by dynamic light scattering (DLS) to analyze size and PDI, while encapsulation efficiency was evaluated using a fluorescence-based assay. Stability was assessed after exposure to physiological pH conditions. Neck angle-dependent differences were observed in particle size distribution, encapsulation behavior, and post-incubation stability, suggesting that toroidal mixer geometry can influence LNP self-assembly and final quality attributes. Overall, toroidal ring micromixers can serve as small-volume screening platforms for selecting LNP formulations and process conditions before scale-up.
