Upon intravenous injection, liposomal particles are rapidly cleared from the
blood by fixed macrophages in the liver, spleen, bone marrow and lymph nodes i.e.
specialized cells of the innate immune system. By reducing the affinity for these fixed
macrophages, therapeutic liposomes containing drugs have been used to target tumor
by the Enhanced Permeability and Retention (EPR) effect. In this communication, we
report minor modifications of lipid compositions that result in the production of 3
classes of liposomes, each suitable for enhanced selectivity of uptake in 1) Bone
Marrow/Spleen (SBMT Lipo); 2) Lymph Nodes (LNT Lipo); and 3) Tumor (TT Lipo).
Keywords: Bone Marrow Imaging, Copper-64, Endothelial Macrophages, Lymph Node Imaging, Nanoparticles, PET, Reticuloendothelial System, Tumor Imaging.
