Synthesis of a lipid conjugate of SO3Lea and its enhancement on liposomal binding to activated platelets

3‘-O-Sulfated Lea (SO3Lea) is one of the most potent natural oligosaccharide ligands of selectins. The specific interactions between SO3Lea and E-/P-selectins are critical in the inflammation process. This paper described an efficient synthesis of a lipid conjugate of SO3Lea and its combination with phospholipid and cholesterol to form SO3Lea-coated liposomes by the freeze-thaw and extrusion method. The size (D = 78 nm) and stability of the resultant glycoliposomes were comparable to that of liposomes without the glycoconjugate. It was further observed that the incorporation of SO3Lea into liposomes could significantly enhance their adhesion to activated platelets as a result of the specific binding between SO3Lea on the glycoliposome and the P-selectin on activated platelets. The glycoliposome constructs may be useful for antiinflammation or for targeted delivery of drugs to endothelial cells that express E- and P-selectins.