The core technology of Yonsei University is to provide a promising MRI contrast agent that includes zinc-containing water-soluble metal oxide nanoparticles and has an improved contrast effect.
Background and unmet needs: The nanoparticle based imaging contrast agent prepared following prior arts, commercially available contrast agents such as Feridex and Resovist, and conventional iron oxide nanoparticles have relatively low magnetic moment and poor MR contrast effect.
The way to resolve these problems is developing MR contrast agents comprising magnetic nanoparticles with enhanced magnetic moment. To achieve the purpose of increasing the magnetic moment, controlling the composition of metal oxide nanoparticles can be one method (Ittrich et al, Rofo 2005, /77, 1151; Shultz et al, J. Magn. Magn, Mater. 2007, 311, 464; Lee et al, Nat. Med. 2007, 13, 95). It has been tried adding various metal dopants to iron oxide nanoparticle.
However, most of possible metallic dopants (e.g. Co, Ni, Mg, Ba, etc) do not increase magnetic moment and, in some cases, even reduce it after the addition (e.g. Co, Ni, Mg, Ba) (Valdes-Solis et al, Nanotechnology 2007, 18, 145603).
Discovery and Achievements: MR contrast agentsof Yonsei University has been developed on the basis of ideas that development of a new metal oxide having more improved magnetic moment is very important in maximizing the MR contrast effect.
The zinc-containing metal oxide nanoparticles are nanoparticles in which zinc atoms/ions are added to the metal oxide nanoparticle. The zinc-containing metal oxide nanoparticles have the excellent magnetic moment and T2 MRI contrast enhancement effect, the high colloidal stability in an aqueous solution, and the low cytotoxicity due to the enhanced bio-compatibility. In addition, they are easily conjugated to a material having a biological activity or a chemical activity to satisfy the optimum condition as the MRI contrast agent.
The zinc-containing metal oxide nano-particles have a chemical formula of: