C14-490 is an ionizable cationic lipid (pKa = 5.94).1 It has been used in the generation of lipid nanoparticles (LNPs) for the delivery of mRNA in vivo.C14-490-containing LNPs accumulate primarily in the fetal mouse liver and, to a lesser extent, in the lungs, intestine, and brain after vitelline vein injection on gestational day 16 (E16).1 CD45-functionalized LNPs containing C14-490 and encapsulating mRNA encoding GFP transfect Jurkat cells, which constitutively express the CD45 receptor (CD45R).C14-490-containing CD45-functionalized LNPs encapsulating Cre mRNA mediate genome modulation in bone marrow hematopoietic stem cells (HSCs) for at least four months after in utero injection in R26mT/mG mice at E13.5.