DSPA

Key Properties

• An anionic phospholipid containing two saturated stearic acid (C18:0) fatty acyl chains and a negatively charged phosphate head group.
• Negatively charged at physiological pH, providing strong electrostatic interaction with cationic lipids, polypeptides, and nucleic acid assemblies.
• High bilayer stability and rigid membrane structure due to long saturated alkyl chains.
• Excellent biocompatibility and low cytotoxicity.
• Practically insoluble in water; soluble in chloroform, methanol, and other organic solvents.
• Usually supplied as a white to off-white solid or powder.
• Storage: −20 °C, desiccated and protected from light.

Applications

• Used as a helper lipid in liposome and lipid nanoparticle (LNP) formulations for gene and nucleic acid delivery.
• Improves encapsulation efficiency and structural stability of DNA, mRNA, siRNA, and negatively charged drug molecules.
• Enhances colloidal stability and membrane rigidity of lipid-based delivery systems.
• Applied in vaccine delivery, non-viral gene therapy, and targeted drug carrier development.
• Serves as a model anionic lipid in biomembrane studies and liposome characterization.
• Used in pH-sensitive and long-circulating liposomal formulations.