A comparative study of cationic lipid-enriched LNPs for mRNA vaccine delivery

Binici, Burcu and Rattray, Zahra and Perrie, Yvonne (2025) A comparative study of cationic lipid-enriched LNPs for mRNA vaccine delivery. International Journal of Pharmaceutics, 682. 125941. ISSN 1873-3476 (https://doi.org/10.1016/j.ijpharm.2025.125941)

[thumbnail of Binici-etal-IJP-2025-A-comparative-study-of-cationic-lipid-enriched-LNPs-for-mRNA-vaccine]
Preview
Text. Filename: Binici-etal-IJP-2025-A-comparative-study-of-cationic-lipid-enriched-LNPs-for-mRNA-vaccine.pdf
Final Published Version
License: Creative Commons Attribution 4.0 logo

Download (7MB)| Preview

Abstract

Lipid nanoparticles (LNPs) play a central role in mRNA vaccine delivery; however, intramuscular (IM) administration may lead to off-target hepatic expression. Here, we tested whether incorporating a cationic lipid (DOTAP) into ALC-0315-based LNPs could enhance local mRNA expression and immunogenicity. We used DODAP as a comparable ionisable lipid to DOTAP. LNPs were formulated by partially replacing their ionisable lipid (ALC-0315) with 5–50% DOTAP or 10–50% DODAP and evaluated for their physicochemical characteristics, in vitro transfection efficiency, in vivo expression and immunogenicity in mice. Substituting ALC-0315 with 10–25% DODAP had minimal impact on LNP physicochemical properties and expression both in vitro and in vivo. However, completely replacing ALC-0315 with DODAP reduced LNP potency in vivo. Incorporation of DOTAP into the LNPs shifted the zeta potential to positive values and altered morphology, with 5–25% DOTAP increasing in vitro transfection efficiency and enhancing local protein expression at the injection site. Notably, 10% DOTAP reduced hepatic expression, suggesting improved localised expression. Immunisation studies with OVA mRNA-LNPs demonstrated that 5% DOTAP enhanced total IgG responses after the prime dose, whereas higher DOTAP or DODAP levels produced minimal differences or reduced responses; these differences were not sustained after booster immunisation, providing no significant long-term benefits.

ORCID iDs

Binici, Burcu, Rattray, Zahra ORCID logoORCID: https://orcid.org/0000-0002-8371-8549 and Perrie, Yvonne ORCID logoORCID: https://orcid.org/0000-0001-8497-2541;