Superparamagnetic ultra-small

Most clinically used nanoparticle contrast agents are iron-oxide based and are grouped into two categories Superparamagnetic iron oxides (SPIOs) are between 500 nm and 50 nm, and ultra-small SPIOs (USPIOs), which are smaller than 50 nm. 

S. Momet, J. Portier, E. Duguet, A method for synthesis and functionalization of ultra small superparamagnetic covalent carriers based on maghemite and dextran, J. Magn. Magn. Mater 2005, 93, 127-134. 

Bumb, A. et al. (2008) Synthesis and characterization of ultra-small superparamagnetic iron oxide nanoparticles thinly coated with silica. Nanotechnology, 19 (33), 335601. 

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