Surface functionalization of magnetoliposomes in view of improving iron oxide-based magnetic resonance imaging contrast agents: Anchoring of gadolinium ions to a lipophilic chelate

• Published in: Analytical biochemistry Vol. 367; no. 2; pp. 266 - 273
• Main Authors: De Cuyper, Marcel, Soenen, Stefaan J.H., Coenegrachts, Kenneth, Beek, Léon Ter
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 15-08-2007
• Subjects: Arsenazo III - chemistry; Contrast Media - chemistry; Ferric Compounds - chemistry; Gadolinium; Gadolinium DTPA - chemistry; Iron oxide; Kinetics; Liposome; Magnetic Resonance Imaging - methods; Magnetics; Magnetoliposome; Metal Nanoparticles - chemistry; MRI contrast agent; Nanoparticle; Pentetic Acid - chemistry; Phosphatidylethanolamines - chemistry; Phospholipid vesicle; Unilamellar Liposomes - chemistry; Iron oxide; Phospholipid vesicle; Magnetoliposome; Nanoparticle; Liposome; Gadolinium; MRI contrast agent
• ISSN: 0003-2697; 1096-0309
• DOI: 10.1016/j.ab.2007.05.006

Small unilamellar phospholipid vesicles containing the phosphatidylethanolamine–diethylene triamine pentaacetic acid (PE–DTPA) conjugate as one of the building stones were constructed. The ability of these colloids to complex gadolinium(III) ions at the surface of both the inner and outer bilayer shells was verified using a colorimetric method with Arsenazo III as a dye indicator. On incubation of these functionalized vesicles with magnetoliposomes (MLs, nanometer-sized magnetite cores encapsulated in a phospholipid bilayer), PE–DTPA percolates into the ML coat. The PE–DTPA content could be fine-tuned by varying the conjugate concentration in the donor vesicles. In the experimental conditions applied, up to 500 Gd
3+ ions were immobilized per ML colloid. The resulting ML–Gd
3+ complexes might have great potential, for example, as a novel magnetic resonance imaging contrast agent.