1,2-dioleoyl-sn-glycero-3-phosphoethanolamine (DOPE)
DOPE, also known as 18:1 (Δ9-Cis) PE, is a phospholipid that contains unsaturated oleic acid at the sn-1 and sn-2 positions, a melting temperature of ~30 °C and a conical shape. DOPE tends to adopt an inverted hexagonal H(II) phase, which destabilizes endosomal membranes and facilitates endosomal escape of lipid nanoparticles.