Benzeneacetic acid, 4-[[(9Z)-1-oxo-9-octadecen-1-yl]oxy]-, 1,1'-[dithiobis(2,1-ethanediyl-1,4-piperidinediyl-2,1-ethanediyl)] ester

SSPalmO-Phe is an ionizable cationic self-degradable disulfide-cleavable (SS-cleavable) proton-activated lipid-like material (SSPalm; pKa = 5.97 in a TNS binding assay).1,2 It has been used in combination with other lipids in the formation of lipid nanoparticles (LNPs) for the delivery of mRNA, siRNA, and antisense oligonucleotides (ASOs). Intravenous administration of mouse erythropoietin (EPO) mRNA in SSPalmO-Phe-containing LNPs increases serum EPO levels in mice.1

1.Tanaka, H., Takahashi, T., Konishi, M., et al.Self-degradable lipid-like materials based on "hydrolysis accelerated by the intra-particle enrichment of reactant (HyPER)" for messenger RNA deliveryAdv. Funct. Mater.301910575(2020) 2.Tanaka, H., Takata, N., Sakurai, Y., et al.Delivery of oligonucleotides using a self-degradable lipid-like materialPharmaceutics13(4)544(2021)