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Magnetic iron oxide nanoparticles |
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Why magnetic nanoparticles? How SPIO works as MRI contrast agents? Commercialized SPIO MRI contrast agents |
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Why magnetic nanoparticles? Size-dependent magnetic properties Magnetic nanoparticles exhibit a variety of unique magnetic phenomena that are drastically different from those of their bulk counterparts. The fundamental magnetic properties such as coercivity (Hc) and susceptibility (¥ö) are dependent to variations in their size, shape, and composition. [1]
When the size of nanoparticles is below a critical value (Dc), each nanoparticle becomes a single magnetic domain and shows superparamagnetic behavior when the temperature is above the blocking temperature (Tb). Such individual nanoparticles have a large constant magnetic moment and behave like a giant paramagnetic atom with a fast response to applied magnetic fields with negligible remanence (residual magnetism) and coercivity (the field required to bring the magnetization to zero). These features make superparamagnetic nanoparticles very attractive for MR contrast agents. [4]
Conjugation with biomolecules Magnetic nanoparticles can also be easily conjugated with biologically important constituents such as DNA, peptides, and antibodies for simultaneous targeted biomedical diagnostics and therapeutics. [1]
created by Yoon Kyung Kim |
