DODAP (1,2-dioleoyl-3-dimethylammonium-propane) is an ionizable cationic lipid with lower cytotoxicity and high transfection efficiency. DODAP is neutral at physiological pH, but acquires a positive charge inside the endosome due to the protonation of free amines when pH is lower than its pKa (<7). The electrostatic interactions between DODAP and naturally occurring anionic lipids in endosomal membranes trigger the release of nucleic acid. These interactions promote membrane lytic non-bilayer structures to enable the intracellular delivery of nucleic acid. A common application is in nanomedicine as an ionizable lipid component of nanocarriers (lipid-polymer hybrid nanoparticles, LPNs), widely used to encapsulate bioactive molecules, including mRNA, siRNA, and plasmid DNA as a treatment for diseases.