Magnetic hyperthermia with magnetic nanoparticles: a status review.

Recent advances in development of potential magnetic nanoparticles for magnetic fluid hyperthermia are summarized. This review covers relation between various size dependent physical properties and their applications subject to modification in synthesis methods. Brief discussion on different heating mechanism of magnetic nanoparticles is provided. This review covers recent progress of various magnetic nanoparticles including core shell type for in vitro, in vivo and pre-clinical trials. The highlight of this review is to build up a bridge between synthesis, surface modification and in vivo- pre-clinical in magnetic fluid hyperthermia.

Structured superparamagnetic nanoparticles for high performance mediator of magnetic fluid hyperthermia: synthesis, colloidal stability and biocompatibility evaluation.

Core-shell structures with magnetic core and metal/polymer shell provide a new opportunity for constructing highly efficient mediator for magnetic fluid hyperthermia. Herein, a facile method is described for the synthesis of superparamagnetic LSMO@Pluronic F127 core-shell nanoparticles. Initially, the surface of the LSMO nanoparticles is functionalized with oleic acid and the polymeric shell formation is achieved through hydrophobic interactions with oleic acid. Each step is optimized to get good dispersion and less aggregation. This methodology results into core-shell formation, of average diameter less than 40 nm, which was stable under physiological conditions. After making a core-shell formulation, a significant increase of specific absorption rate (up to 300%) has been achieved with variation of the magnetization (<20%). Furthermore, this high heating capacity can be maintained in various simulated physiological conditions. The observed specific absorption rate is almost higher than Fe3O4. MTT assay is used to evaluate the toxicity of bare and core-shell MNPs. The mechanism of cell death by necrosis and apoptosis is studied with sequential staining of acridine orange and ethidium bromide using fluorescence and confocal microscopy. The present work reports a facile method for the synthesis of core-shell structure which significantly improves SAR and biocompatibility of bare LSMO MNPs, indicating potential application for hyperthermia.

Induction heating studies of dextran coated MgFe2O4 nanoparticles for magnetic hyperthermia.

MgFe(2)O(4) nanoparticles with sizes around 20 nm have been prepared by a combustion method and functionalized with dextran for their possible applications in magnetic particle hyperthermia. The induction heating study of these nanoparticles at different magnetic field amplitudes, from 6.7 kA m(-1) to 26.7 kA m(-1), showed self-heating temperature rise up to 50.25 °C and 73.32 °C (at 5 mg mL(-1) and 10 mg mL(-1) concentrations in water respectively) which was primarily thought to be due to hysteresis losses activated by an AC magnetic field. The dextran coated nanoparticles showed a maximum specific absorption rate (SAR) of about 85.57 W g(-1) at 26.7 kA m(-1) (265 kHz). Dextran coated nanoparticles at concentrations below 1.8 mg mL(-1) exhibit good viability above 86% on mice fibroblast L929 cells. The results suggest that combustion synthesized MgFe(2)O(4) nanoparticles coated with dextran can be used as potential heating agents in magnetic particle hyperthermia. Uncoated and dextran coated samples were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM) and vibrating sample magnetometry (VSM), Fourier transform infrared spectroscopy (FTIR), thermogravimetric-differential thermal analysis (TG-DTA) and zeta potential-DLS studies.

Functionalization of La(0.7)Sr(0.3)MnO3 nanoparticles with polymer: studies on enhanced hyperthermia and biocompatibility properties for biomedical applications.

Now-a-days surface functionalized La(0.7)Sr(0.3)MnO(3) (LSMO) nanoparticles by different biocompatible polymers are attracted considerable interest in various biomedical applications in general and magnetic fluid hyperthermia treatment of cancer in particular. In this paper La(0.7)Sr(0.3)MnO(3) nanoparticles are synthesized and functionalized with polymer (dextran, with mean particle size ~25 nm). Magnetic measurements of both coated and uncoated particles reveal the superparamagnetic nature at room temperature. The resulting coated particles form a stable suspension in an aqueous environment at physiological pH and possess a narrow hydrodynamic size distribution. In vitro cytotoxicity of the MNPs has been assessed under Trypan blue dye exclusion and MTT assay on HeLa and L929 cell lines. The results demonstrate that dextran functionalized nanoparticles have no significant effect on cell viability within the tested concentrations (0.2-1 mg/mL) as compared to bare LSMO. Magnetic fluid hyperthermia studies have been done in detail; the influence of an applied alternating current (AC) magnetic field on heat generation is presented in brief. Dextran functionalized LSMO has the higher Specific absorption rate (SAR) value than the bare LSMO. After functionalization with dextran the SAR values of LSMO nanoparticles increased from 25 to 51 W/g. The study shows that the rise in temperatures by these nanoparticles could be safely controlled around Curie temperature (T(c)).

Enhanced colloidal stability of polymer coated La0.7Sr0.3MnO3 nanoparticles in physiological media for hyperthermia application.

Surface of La(0.7)Sr(0.3)MnO3 (LSMO) magnetic nanoparticles (MNPs) is functionalized with polymer (dextran) and their colloidal stability in various mediums is carried out. The influence of the surface functionalization of LSMO MNPs on their colloidal stability in physiological media is studied and correlated with their hyperthermia properties. Many studies have concerned the colloidal stability of MNPs coated with polymer, but their long-term stability when such complexes are exposed to physiological media is still not well understood. After zeta potential study, it is found that the dextran coating on MNPs improves the colloidal stability in water as well as in physiological media like PBS. The specific absorption rates (SAR) of these MNPs are found to be in 50-85 W/g in different concentrations of glucose and NaCl; and there values are suitable for hyperthermia treatment of cancer cells under AC magnetic field. After incorporation of MNPs up to 0.2-1mg/mL in 2 × 10(5)cells/mL (L929), the apoptosis and necrosis studies are carried out by acridine orange and ethidium bromide (AO and EB) staining and followed by visualization of microstructures under a fluorescence microscope. It is found that there are no morphological changes (i.e. no signs of cell rounding, bubble formation on the membrane and nuclear fragmentation) suggesting biocompatibility of dextran coated LSMO nanoparticles up to these concentrations.