What is SM-102?

What is SM-102?

Published by BroadPharm on February 06, 2023

Lipid nanoparticles have recently come into vogue as an effective delivery vehicle for mRNA vaccines and disease treatment. One of the more notable lipids is the ionizable lipid SM-102, used in the formulation of the COVID-19 vaccine mRNA-1273 - patented by Moderna.

SM-102 is an amino lipid with a tertiary amine and a branched tail linked through ester bonds. The tertiary amine allows the lipid to form a zwitterionic lipid. SM-102 is a colorless oily compound with a molecular weight of 710.2 and a CAS number of 2089251-47-6. The IUPAC name is heptadecan-9-yl 8-[2-hydroxyethyl-(6-oxo-6-undecoxyhexyl)amino]octanoate.

SM-102 can be synthesized through the route as shown in Figure 1.

Figure 1. Shows the synthesis route of SM-102.

SM-102 is an ideal drug carrier due to its fast clearance rate, tolerability, immunogenicity, and protein expression. While SM-102 is soluble in organic solvents, it forms a membrane when suspended in polar solvents. This property has enabled scientists to mold these lipids into mRNA therapeutics. SM-102 plays a significant role in the formulation of mRNA-1273. SM-102 remains neutral at physiological pH and takes on a positive charge in an acidic environment. This property to remain neutral at physiological pH allows the lipid to have fewer interactions with the anionic membranes of blood cells. SM-102's ability to take on a positive charge plays a crucial role after cellular uptake. When SM-102 interacts with the acidic endosome, it becomes protonated and forms cone-shaped ion pairs that drive the transition from a bilayer to an inverted hexagon phase. This phase promotes endosomal escape and the release of the mRNA into the cytosol. Once the mRNA is released, SM-102 is metabolized through ester hydrolysis, and the remaining aliphatic head group is eliminated via biliary and renal clearance.

With the recent advances in lipid technology, the scientific community is on the precipice of creating many new therapeutics. To further empower drug delivery research, BroadPharm offers a broad selection of ionizable lipids, cationic lipids, PEG lipids, and Phospholipids. BroadPharm also offers custom lipid syntheses to satisfy your research need.

Please don't hesitate to contact sales@broadpharm.com or call (858) 677-6760 for timely support.

Journal References

Han, X., Zhang, H., Butowska, K. et al. An ionizable lipid toolbox for RNA delivery. Nat Commun 12, 7233 (2021). https://doi.org/10.1038/s41467-021-27493-0

Hou, X., Zaks, T., Langer, R. et al. Lipid nanoparticles for mRNA delivery. Nat Rev Mater 6, 1078-1094 (2021). https://doi.org/10.1038/s41578-021-00358-0