ABSTRACT
Over the last decade, nanotechnology has developed to such an extent that it has become possible to fabricate, characterize and specifi cally tailor the functional properties of nanoparticles for biomedical applications and diagnostics. Magnetic nanoparticles (MNPs) are a class of nanoparticles (i.e., engineered particulate materials of < 100 nm) that can be manipulated under the infl uence of an external magnetic fi eld. MNPs are commonly composed of magnetic elements, such as iron, nickel, cobalt and their oxides. Based on their unique mesoscopic physical, chemical, thermal, and mechanical properties, superparamagnetic nanoparticles offer a high potential for several biomedical applications. These include: (a) cellular therapies, such as cell labeling and targeting, where they can also be used as a tool for cell biology research to separate and purify cell populations; (b) tissue repair; (c) drug delivery; (d) magnetic resonance imaging (MRI); (e) hyperthermic cancer therapy; and (f) magnetofection (Gupta and Gupta 2005). When further “functionalized” with drugs and bioactive agents, such as peptides and nucleic acids, MNPs form distinct particulate systems that penetrate cell and tissue barriers and offer organ-specifi c therapeutic and diagnostic modalities. The ability of MNPs to be functionalized and concurrently respond to a magnetic fi eld has made them a useful tool for theragnostics (the fusion of therapeutic and diagnostic technologies to target and individualize medicine). However, variations in properties, such as MNP composition, shape, size, surface chemistry and dispersion, may infl uence their biodistribution and toxic potential.
