Multifunctional Magnetic Nanoparticles: Design, Synthesis, and Biomedical Applications

Abstract

The combination of nanotechnology and molecular biology has developed into an emerging research area: nanobiotechnology. Magnetic nanoparticles are well-established nanomaterials that offer controlled size, ability to be manipulated externally, and enhancement of contrast in magnetic resonance imaging (MRI). As a result, these nanoparticles could have many applications in biology and medicine, including protein purification, drug delivery, and medical imaging. Because of the potential benefits of multimodal functionality in biomedical applications, researchers would like to design and fabricate multifunctional magnetic nanoparticles. Currently, there are two strategies to fabricate magnetic nanoparticle-based multifunctional nanostructures. The first, molecular functionalization, involves attaching antibodies, proteins, and dyes to the magnetic nanoparticles. The other method integrates the magnetic nanoparticles with other functional nanocomponents, such as quantum dots (QDs) or metallic nanoparticles. Because they can exhibit several features synergistically and deliver more than one function simultaneously, such multifunctional magnetic nanoparticles could have unique advantages in biomedical applications. In this Account, we review examples of the design and biomedical application of multifunctional magnetic nanoparticles. After their conjugation with proper ligands, antibodies, or proteins, the biofunctional magnetic nanoparticles exhibit highly selective binding. These results indicate that such nanoparticles could be applied to biological medical problems such as protein purification, bacterial detection, and toxin decorporation. The hybrid nanostructures, which combine magnetic nanoparticles with other nanocomponents, exhibit paramagnetism alongside features such as fluorescence or enhanced optical contrast. Such structures could provide a platform for enhanced medical imaging and controlled drug delivery. We expect that the combination of unique structural characteristics and integrated functions of multicomponent magnetic nanoparticles will attract increasing research interest and could lead to new opportunities in nanomedicine.

Coexistence of plasmonic and magnetic properties in Au89Fe11 nanoalloys

“…1F). This one-pot surface conjugation of AuFeNPs with the desired thiolated molecules is highly important in most technological applications [11][12][13] and in the accurate characterization of the magnetic and plasmonic properties of well-dispersed (i.e., not agglomerated) alloy nanoparticles.…”

“…28 Moreover, the AuFeNPs obtained by all previous methods were found to have problems related to surface accessibility, 15,[31][32][33][34][35][36][37][38][39][40][41][42][43][44][45][46] which is important to catalytic applications [18][19][20] and for conjugation with functional molecules. [11][12][13] Thus, new low-cost and non-toxic synthetic methods that allow the synthesis of large amounts of well-dispersed and accessible nanoparticles avoiding the thermodynamic limitations to alloy formation are needed.…”

Octapod iron oxide nanoparticles as high-performance T2 contrast agents for magnetic resonance imaging

“…Approximately 35% of clinical MR scans need contrast agents to improve their sensitivity and diagnostic accuracy 4 . For example, superparamagnetic iron oxide nanoparticles are the prevailing T 2 contrast agents, especially for the imaging and detection of lesions in normal tissues [5][6][7][8] . However, there are several challenges for using T 2 contrast agents (for example, Feridex and Resovist) in the clinic.…”

The design and utility of polymer-stabilized iron-oxide nanoparticles for nanomedicine applications

“…In this review, we focus on the polymer modifi cation of the nanoparticles, and provide only minimal information on the inorganic synthesis of IONPs. For more detailed information on IONP synthesis, readers are referred to other reviews [3,4]. …”