Synthesis of an amphiphilic tetraantennary mannosyl conjugate and incorporation into liposome carriers.

We have synthesized a novel conjugate (Man(4)K(3)DOG) composed of a tetramannosyl head group connected, via a polyethylene glycol spacer, to a lipid moiety. This amphiphilic molecule was easily incorporated into the bilayers of liposomes. As expected from the clustering effect, such multivalent mannose residues when exposed on the surface of the vesicles showed much higher binding affinity for Concanavalin A than their monomannosyl analogue. Mannosylated liposomes prepared with the tetravalent antenna could be promising carriers for e.g., loading dendritic cells with antigens for vaccination purposes.