Notes: Lipid A9 is an ionizable cationic lipid (pKa = 6.27) that has been used in the generation of lipid nanoparticles (LNPs) for the delivery of mRNA and siRNA in vivo.{60925,66862} LNPs containing lipid A9 and encapsulating non-stimulatory siRNA increase plasma levels of chemokine (C-C motif) ligand 2 (CCL2), indicating activation of the innate immune response, and decrease body weight in mice.{66862}