Magnetic Glyconanoparticles as a Versatile Platform for Selective Immunolabeling and Imaging of Cells

A versatile nanoplatform based on magnetic glyconanoparticles (glyco-ferrites) to attach well-oriented antibodies is described. An efficient ligand exchange process has been used to prepare water-soluble 6-nm-sized core−shell Fe₃O₄@Au nanoparticles bearing amphiphilic carbohydrates and aliphatic ethylene glycol chains ended in a carboxyl group. The covalent immobilization through the carboxyl group of an Fc receptor (protein G) enables successful well-oriented capture of immunoglobulins G onto the magnetic glyconanoparticle. A thorough characterization of structure and biofunctionality of the constructs is carried out by different techniques. The selective immunolabeling of cells by the antibody-magnetic glyconanoparticle conjugates is demonstrated by magnetic resonance imaging (MRI), as well as by fluorescence techniques.