[5][6][7] Lipid nanoparticles are an extension of earlier RNA transfection methods such as cationic liposomes.

Ionisable lipids like SM-102 hold a relatively (/ close to) neutral charge at physiological pH but are positively charged within the nanoparticle (the amine group is protonated to form an ammonium cation).

[8] SM-102 is also used for non-invasive bioluminescence imaging when SM-102 containing luciferase-encoding mRNA is used for in-vivo luciferase expression in animal models.

[9][10][11] The preparation of SM-102 was first described in a patent application to lipid nanoparticles by Moderna in 2017.

[12]: 139–142  The final step is an alkylation reaction in which a secondary amine is combined with a lipid bromo ester.