Lipid 20b​​ is a thiophene-based ionizable lipid synthesized via the Gewald reaction. It features dual unsaturated linoleic tails (C18:2) attached to the same side of the thiophene core and a tertiary amine headgroup. Formulated into LNPs (~100 nm, PDI ~0.2) with DSPC/cholesterol/DMG-PEG, it exhibits high mRNA encapsulation (>90%). Unlike traditional lipids, 20b lacks a pH-dependent ionization profile, likely due to electron delocalization in the thiophene ring. Intravenously, 20b LNPs transfect the liver and spleen in mice. Notably, subretinal delivery in mice and non-human primates (NHPs) achieved robust mRNA expression in photoreceptors (35% rods, 45% cones at high dose) and retinal pigment epithelium (RPE) with minimal acute toxicity. Immunosuppression enhanced rod transfection efficiency. High-dose administration in NHPs caused subretinal debris, but low doses (2.5 µg mRNA) maintained retinal health. This lipid demonstrates potential for liver and retinal gene therapy.

Providing storage is as stated on the product vial and the vial is kept tightly sealed, the product can be stored for up to 24 months.
Wherever possible, you should prepare and use solutions on the same day. However, if you need to make up stock solutions in advance, we recommend that you store the solution as aliquots in tightly sealed vials at -20°C. Generally, these will be useable for up to one month. Before use, and prior to opening the vial we recommend that you allow your product to equilibrate to room temperature for at least 1 hour.

Thiophene-based lipids for mRNA delivery to pulmonary and retinal tissues-PNAS-March 4, 2024 121 (11) e2307813120