Lipid 331 is a biodegradable cyclic ionizable cationic lipid (pKa = 7.53) that has been used in the formation of lipid nanoparticles (LNPs) for the delivery of mRNA in vitro and in vivo.[1] LNPs containing lipid 331 and encapsulating 5-methoxyuridine-modified mRNA encoding ovalbumin induce IFN regulatory factor (IRF) activation in a reporter assay using THP-1 monocytes. Intranasal administration of LNPs containing lipid 331 and DOTAP and encapsulating mRNA encoding a fusion of the receptor-binding domain (RBD) of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike glycoprotein, also known as surface glycoprotein, with mouse complement C3d as an adjuvant increase serum anti-SARS-CoV-2 spike glycoprotein RBD IgG titers in mice.
References:
[1].Li, B., Jiang, A.Y., Raji, I., et al.Enhancing the immunogenicity of lipid-nanoparticle mRNA vaccines by adjuvanting the ionizable lipid and the mRNANat. Biomed. Eng.(2023).