Targeting of liposomes via PSGL1 for enhanced tumor accumulation.
Carlisle R., Seymour LW., Coussios CC.
PURPOSE: To improve the delivery of liposomes to tumors using P-selectin glycoprotein ligand 1 (PSGL1) mediated binding to selectin molecules, which are upregulated on tumorassociated endothelium. METHODS: PSGL1 was orientated and presented on the surface of liposomes to achieve optimal selectin binding using a novel streptavidin-protein G linker molecule. Loading of PSGL1 liposomes with luciferin allowed their binding to e-selectin and activated HUVEC to be quantified in vitro and their stability, pharmacokinetics and tumor accumulation to be tested in vivo using murine models. RESULTS: PSGL1 liposomes showed 5-fold (p 7-fold (p 3-fold enhancement in the level of delivery to tumors (p