Nanomedicine: Magnetic Nanoparticles and their Biomedical Applications

Abstract

During this past decade, science and engineering have seen a rapid increase in interest for nanoscale materials with dimensions less than 100 nm, which lie in the intermediate state between atoms and bulk (solid) materials. Their attributes are significantly altered relative to the corresponding bulk materials as they exhibit size dependent behavior such as quantum size effects (depending on bulk Bohr radius), optical absorption and emission, coulomb staircase behavior (electrical transport), superparamagnetism and various unique properties. They are active components of ferrofluids, recording tape, flexible disk recording media along with potential future applications in spintronics: a new paradigm of electronics utilizing intrinsic charge and spin of electrons for ultra-high-density data storage and quantum computing. They are used in a gamut of biomedical applications: bioseparation of biological entities, therapeutic drugs and gene delivery, radiofrequency-induced destruction of cells and tumors (hyperthermia), and contrast-enhancement agents for magnetic resonance imaging (MRI). The magnetic nanoparticles have optimizable, controllable sizes enabling their comparison to cells (10-100 µm), viruses (20-250 nm), proteins (3-50 nm), and genes (10-100 nm). Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), Atomic Force Microscopy (AFM) and X-ray photoelectron spectroscopy (XPS) provide necessary characterization methods that enable accurate structural and functional analysis of interaction of the biofunctional particles with the target bioentities. The goal of the present discussion is to provide a broad review of magnetic nanoparticle research with a special focus on the synthesis, functionalization and medical applications of these particles, which have been carried out during the past decade, and to examine several prospective directions.

Magnetic fluid hyperthermia induced by radiofrequency capacitive field for the treatment of transplanted subcutaneous tumors in rats

“…Oscillation of high-frequency electrical and magnetic fields produces movement of ions, rotation of polar molecules and distortion of non-polar molecules, with resultant heat generation. However, the heating effect of MF under RCF with 27.12 MHz and 0-200 W for treating tumors has been not reported (16,17).…”

Hyperthermic potentiation of cisplatin by magnetic nanoparticle heaters is correlated with an increase in cell membrane fluidity

“…26,27 Recent studies have also explored magnetic nanoparticles as a means of enhancing chemotherapeutic efficacy. 28 When inducing hyperthermia using magnetic nanoparticles, the physical mechanisms inherent in the dissipation of heat by these particles may exert an additional stress that goes beyond thermal effects and which results in enhanced potentiation of chemotherapeutics. Previously, we reported that magnetic fluid hyperthermia resulted in enhanced cytotoxicity when compared with hot water hyperthermia alone in two separate cell lines, and subsequently we showed that magnetic fluid hyperthermia resulted in significantly enhanced cytotoxicity when combined with cDDP, as compared with hyperthermia using a water bath.…”

Nanoparticle-cored dendrimers: functional hybrid nanocomposites as a new platform for drug delivery systems

“…2 Magnetic nanoparticles (MNPs) have generated considerable interest in the scientific world especially in the area of biomedicine and technology, particularly in magnetic storage media, 16 biosensing, 17,18 inks and paints, 19 drug delivery and contrast agents in magnetic resonance imaging. 20 NPs are generally synthesized in either aqueous or organic solutions and thus require sophisticated coating for stability. 21 The aggregation processes occur frequently in the colloidal systems of metal or semiconductor NPs, and severely restrict their utilization in different applications.…”