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Recent progress on magnetic iron oxide nanoparticles: synthesis, surface functional strategies and biomedical applications

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ABSTRACT

This review focuses on the recent development and various strategies in the preparation, microstructure, and magnetic properties of bare and surface functionalized iron oxide nanoparticles (IONPs); their corresponding biological application was also discussed. In order to implement the practical in vivo or in vitro applications, the IONPs must have combined properties of high magnetic saturation, stability, biocompatibility, and interactive functions at the surface. Moreover, the surface of IONPs could be modified by organic materials or inorganic materials, such as polymers, biomolecules, silica, metals, etc. The new functionalized strategies, problems and major challenges, along with the current directions for the synthesis, surface functionalization and bioapplication of IONPs, are considered. Finally, some future trends and the prospects in these research areas are also discussed.

No MeSH data available.


(a) The SAR values of the different sized Fe3O4 NPs for different mPEG: 9 nm (orange), 19 nm (yellow), 31 nm (blue). (b) A schematic diagram of nanoparticle based hyperthermia agents with iron oxide core and varied mPEG coating. (Reprinted with permission from X L Liu et al 2012 J. Mater. Chem.22 8235. Copyright 2012 Royal Society of Chemistry.)
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Figure 24: (a) The SAR values of the different sized Fe3O4 NPs for different mPEG: 9 nm (orange), 19 nm (yellow), 31 nm (blue). (b) A schematic diagram of nanoparticle based hyperthermia agents with iron oxide core and varied mPEG coating. (Reprinted with permission from X L Liu et al 2012 J. Mater. Chem.22 8235. Copyright 2012 Royal Society of Chemistry.)

Mentions: Some reports reveal that the surface functionalization improved the hyperthermic effect. As shown in figure 24, Liu et al reported that enhanced SAR with decreased surface coating thickness was observed and ascribed to the increased Brownian loss, improved thermal conductivity as well as improved dispersibility [352]. Moreover, the inorganic coating can also improve the SAR value. For example, Mohammad et al found that the hyperthermic effect of SPIONs is enhanced dramatically on coating with Au. The results indicated possibilities for utilization of very low frequency oscillating magnetic fields in hyperthermia treatment. The gold coating should retain the superparamagnetic fraction of the SPIONs much better than when compared to uncoated SPIONs alone; this leads to a higher energy of magnetic anisotropy of superparamagnetic NPs within the gold shell as compared to uncoated SPIONs. Excellent hyperthermia exhibited by SPION@Au NPs coupled with their lack of cytotoxicity was anticipated to make them into suitable candidates for thermolysis of cancer cells [353]. Recently, Balvata et al reported their magnetic hyperthermia results obtained after intratumoral injection, demonstrating that micromolar concentrations of iron given within the modified core–shell Fe/Fe3O4 NPs caused a significant anti-tumor effect on murine subcutaneous mouse melanoma with three short 10 min alternating magnetic field (AFM) exposures. These results indicated that intratumoral administration of surface modified MNPs attenuated mouse melanoma after AMF exposure, and these MNPs were capable of causing an anti-tumor effect in a mouse melanoma model after only a short AMF exposure time [354].


Recent progress on magnetic iron oxide nanoparticles: synthesis, surface functional strategies and biomedical applications
(a) The SAR values of the different sized Fe3O4 NPs for different mPEG: 9 nm (orange), 19 nm (yellow), 31 nm (blue). (b) A schematic diagram of nanoparticle based hyperthermia agents with iron oxide core and varied mPEG coating. (Reprinted with permission from X L Liu et al 2012 J. Mater. Chem.22 8235. Copyright 2012 Royal Society of Chemistry.)
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC5036481&req=5

Figure 24: (a) The SAR values of the different sized Fe3O4 NPs for different mPEG: 9 nm (orange), 19 nm (yellow), 31 nm (blue). (b) A schematic diagram of nanoparticle based hyperthermia agents with iron oxide core and varied mPEG coating. (Reprinted with permission from X L Liu et al 2012 J. Mater. Chem.22 8235. Copyright 2012 Royal Society of Chemistry.)
Mentions: Some reports reveal that the surface functionalization improved the hyperthermic effect. As shown in figure 24, Liu et al reported that enhanced SAR with decreased surface coating thickness was observed and ascribed to the increased Brownian loss, improved thermal conductivity as well as improved dispersibility [352]. Moreover, the inorganic coating can also improve the SAR value. For example, Mohammad et al found that the hyperthermic effect of SPIONs is enhanced dramatically on coating with Au. The results indicated possibilities for utilization of very low frequency oscillating magnetic fields in hyperthermia treatment. The gold coating should retain the superparamagnetic fraction of the SPIONs much better than when compared to uncoated SPIONs alone; this leads to a higher energy of magnetic anisotropy of superparamagnetic NPs within the gold shell as compared to uncoated SPIONs. Excellent hyperthermia exhibited by SPION@Au NPs coupled with their lack of cytotoxicity was anticipated to make them into suitable candidates for thermolysis of cancer cells [353]. Recently, Balvata et al reported their magnetic hyperthermia results obtained after intratumoral injection, demonstrating that micromolar concentrations of iron given within the modified core–shell Fe/Fe3O4 NPs caused a significant anti-tumor effect on murine subcutaneous mouse melanoma with three short 10 min alternating magnetic field (AFM) exposures. These results indicated that intratumoral administration of surface modified MNPs attenuated mouse melanoma after AMF exposure, and these MNPs were capable of causing an anti-tumor effect in a mouse melanoma model after only a short AMF exposure time [354].

View Article: PubMed Central - PubMed

ABSTRACT

This review focuses on the recent development and various strategies in the preparation, microstructure, and magnetic properties of bare and surface functionalized iron oxide nanoparticles (IONPs); their corresponding biological application was also discussed. In order to implement the practical in vivo or in vitro applications, the IONPs must have combined properties of high magnetic saturation, stability, biocompatibility, and interactive functions at the surface. Moreover, the surface of IONPs could be modified by organic materials or inorganic materials, such as polymers, biomolecules, silica, metals, etc. The new functionalized strategies, problems and major challenges, along with the current directions for the synthesis, surface functionalization and bioapplication of IONPs, are considered. Finally, some future trends and the prospects in these research areas are also discussed.

No MeSH data available.