Water-soluble magnetic glyconanoparticles based on metal-doped ferrites coated with gold: Synthesis and characterization

Novel bimetallic superparamagnetic XFe2O4@ Au (X = Fe, Mn and Co) nanocrystals of different sizes were synthesized in high-boiling point ether solvent in two steps. Reduction of gold salts on pre-made seeds in the presence of surfactants was performed resulting in the uniform coverage of the seeds. HAADF- and EDXS-STEM elemental mapping indicate the presence of two metals in the same nanocrystal. The apolar solvent-soluble nanoparticles were transferred into water using an amphiphilic linker and different neoglycoconjugates. The as prepared glyco-ferrites are superparamagnetic at room temperature and present comparable or higher transverse relaxivities (T2) than commercial contrast agents like Endorem, Resovist or Sinerem. The carbohydrate coating provides high stability under physiological conditions, low cytotoxicity and lack of immunogenicity. All glyco-ferrites prepared show comparable relaxation times in phantom imaging.