244cis

244cis is an ionizable cationic lipid that has been used in the generation of lipid nanoparticles (LNPs).¹ LNPs containing 244cis and encapsulating an mRNA reporter specifically accumulate in the lungs and induce lower serum chemokine (C-C motif) ligand 2 (CCL2) levels than LNPs containing SM-102 in mice. Intravenous administration of LNPs containing 244cis and encapsulating mRNA encoding Cre recombinase increases tdTomato fluorescence in lung endothelial, epithelial, and immune cells, as well as fibroblasts, in mice expressing a floxed STOP codon to prevent tdTomato expression.