1120-45-2Relevant articles and documents
Probing temperature-sensitive behavior of pNIPAAm-coated iron oxide nanoparticles using frequency-dependent magnetic measurements
Kalele, Suchita,Narain, Ravin,Krishnan, Kannan M.
, p. 1377 - 1380 (2009)
Ferromagnetic iron oxide nanoparticles of about 33 nm in diameter were synthesized by high-temperature decomposition of an iron-oleate complex, using octadecene as the solvent. These particles were subsequently coated with polyN-isopropylacrylamide (pNIPA
Probing the Consequences of Cubic Particle Shape and Applied Field on Colloidal Crystal Engineering with DNA
Urbach, Zachary J.,Park, Sarah S.,Weigand, Steven L.,Rix, James E.,Lee, Byeongdu,Mirkin, Chad A.
, p. 4065 - 4069 (2021)
In a magnetic field, cubic Fe3O4 nanoparticles exhibit assembly behavior that is a consequence of a competition between magnetic dipole–dipole and ligand interactions. In most cases, the interactions between short hydrophobic ligands dominate and dictate assembly outcome. To better tune the face-to-face interactions, cubic Fe3O4 nanoparticles were functionalized with DNA. Their assembly behaviors were investigated both with and without an applied magnetic field. Upon application of a field, the tilted orientation of cubes, enabled by the flexible DNA ligand shell, led to an unexpected crystallographic alignment of the entire superlattice, as opposed to just the individual particles, along the field direction as revealed by small and wide-angle X-ray scattering. This observation is dependent upon DNA length and sequence and cube dimensions. Taken together, these studies show how combining physical and chemical control can expand the possibilities of crystal engineering with DNA.
Facile non-hydrothermal synthesis of oligosaccharide coated sub-5 nm magnetic iron oxide nanoparticles with dual MRI contrast enhancement effects
Huang, Jing,Wang, Liya,Zhong, Xiaodong,Li, Yuancheng,Yang, Lily,Mao, Hui
, p. 5344 - 5351 (2014)
Ultrafine sub-5 nm magnetic iron oxide nanoparticles coated with oligosaccharides (SIO) with dual T1-T2 weighted contrast enhancing effects and fast clearance have been developed as magnetic resonance imaging (MRI) contrast agents. Excellent water solubility, biocompatibility and high stability of such sub-5 nm SIO nanoparticles were achieved by using the in situ polymerization coating method, which enables glucose to form oligosaccharides directly on the surface of hydrophobic iron oxide nanocrystals. Reported ultrafine SIO nanoparticles exhibit a longitudinal relaxivity (r1) of 4.1 mM-1 s-1 and a r 1/r2 ratio of 0.25 at 3 T (clinical field strength), rendering improved T1 or brighter contrast enhancement in T1-weighted MRI in addition to typical T2 or darkening contrast of conventional iron oxide nanoparticles. Such dual contrast effects can be demonstrated by liver imaging with T2 darkening contrast in the liver parenchyma but T1 bright contrast in the hepatic vasculature. More importantly, this new class of ultrafine sub-5 nm iron oxide nanoparticles showed much faster body clearance than those with larger sizes, promising better safety for clinical applications.
Colloidal synthesis of ultrathin γ-Fe2O3 nanoplates
Ding, Xiangui,Bao, Liu,Jiang, Jiang,Gu, Hongwei
, p. 9314 - 9320 (2014)
A facile method of synthesizing γ-Fe2O3 ultrathin nanoplates has been developed. These nanoplates are single crystalline and superparamagnetic at room temperature, with a thickness of only 1.4 nm. FTIR analysis has shown that the coordination mode between Fe and carboxyl group is dominated by bidentate configuration in the as prepared iron oleate complex, which is the key for producing the nanoplate morphology. By changing the reaction temperatures, the lateral size and thickness of nanoplates can be varied.
Doxorubicin-loaded Fe3O4@SiO2 nanoparticles as magnetic targeting agents for combined photothermal-chemotherapy of cancer
Ding, Bei,Shen, Song,Wu, Lin,Qi, Xueyong,Ni, Haihua,Ge, Yanru
, p. 858 - 860 (2015)
Specific photothermal-chemotherapy is a promising tool in the treatment of the cancer. We developed silica-coated Fe3O4 nanoparticles as photothermal agents and magnetic targeting drug delivery system. Doxorubicin-loaded silica-coated Fe3O4 nanoparticles showed pH-responsive release properties. A synthetic antitumor effect of photothermal-chemotherapy was realized on MCF-7 cells.
Facile synthesis of stable magnetic fluid using size-controlled Fe 3O4 nanoparticles
Bateer, Buhe,Qu, Yang,Tian, Chungui,Du, Shichao,Ren, Zhiyu,Wang, Ruihong,Pan, Kai,Fu, Honggang
, p. 34 - 38 (2014)
Magnetic fluids based on superparamagnetic, well-crystalline and mono-dispersed Fe3O4 nanoparticles are synthesized by a facile thermal decomposition method. Low-cost Fe(oleate)3 is used as ferrous resource, and paraffin oil is introduced as solvent and carrier simultaneously. Fe3O4 nanoparticles with three kinds of different size (12, 16 and 20 nm), exhibiting different saturation magnetization of 65.51, 68.03 and 74.48 emu/g, respectively, are prepared easily by controlling the thermal decomposition time. Magnetic performance and viscosity-temperature characteristics of the magnetic fluid are also studied. It is found that the saturation magnetization of the magnetic fluid with 5% Fe3O4 mass percentage is 2.94 emu/g, which exhibits a good viscosity temperature characteristics compared with paraffin carrier.
S-Doped TiSe2 Nanoplates/Fe3O4 Nanoparticles Heterostructure
Yang, Jun,Zhang, Yufei,Zhang, Yizhou,Shao, Jinjun,Geng, Hongbo,Zhang, Yu,Zheng, Yun,Ulaganathan, Mani,Dai, Zhengfei,Li, Bing,Zong, Yun,Dong, Xiaochen,Yan, Qingyu,Huang, Wei
, (2017)
2D Sulfur-doped TiSe2/Fe3O4 (named as S-TiSe2/Fe3O4) heterostructures are synthesized successfully based on a facile oil phase process. The Fe3O4 nanoparticles, with an average size of 8 nm, grow uniformly on the surface of S-doped TiSe2 (named as S-TiSe2) nanoplates (300 nm in diameter and 15 nm in thickness). These heterostructures combine the advantages of both S-TiSe2 with good electrical conductivity and Fe3O4 with high theoretical Li storage capacity. As demonstrated potential applications for energy storage, the S-TiSe2/Fe3O4 heterostructures possess high reversible capacities (707.4 mAh g?1 at 0.1 A g?1 during the 100th cycle), excellent cycling stability (432.3 mAh g?1 after 200 cycles at 5 A g?1), and good rate capability (e.g., 301.7 mAh g?1 at 20 A g?1) in lithium-ion batteries. As for sodium-ion batteries, the S-TiSe2/Fe3O4 heterostructures also maintain reversible capacities of 402.3 mAh g?1 at 0.1 A g?1 after 100 cycles, and a high rate capacity of 203.3 mAh g?1 at 4 A g?1.
P(EO-co-LLA) functionalized Fe3O4@mSiO2 nanocomposites for thermo/pH responsive drug controlled release and hyperthermia
Guo, Wei,Yang, Chunyu,Lin, Huiming,Qu, Fengyu
, p. 18056 - 18065 (2014)
The Fe3O4@mSiO2 nanocarrier that consisted of a magnetic Fe3O4 nanoparticle core and a mesoporous silica (mSiO2) shell was synthesized. It shows a uniform sphere morphology about 65 nm in diameter. Considering the magnetic hyperthermia of Fe3O4 under an alternating magnetic field (AMF), a thermo-sensitive polymer, poly[(ethylene glycol)-co-(l-lactide)] (P(EO-co-LLA)), was used as gatekeeper coating outside Fe3O4@mSiO2 to regulate the drug release behavior. The design of the nanocarrier was expected to block off the pores at low temperature and to reopen them at high temperature reversibly. The obtained hybrid nanocomposites were capable of loading the anti-cancer drug doxorubicin (DOX) and controlled drug release behavior trigged by the hyperthermia of Fe3O4 under AMF. Besides, the nanocarriers also show pH-sensitive drug release based on the slight differences between the tumor (weakly acid) and the normal tissue (weakly alkaline). What's more, the chemotherapy of DOX combined with magnetic hyperthermia can improve the cytotoxicity obviously. On the basis of the high stability and excellent controlled release performance, the multifunctional nanocarriers exhibit potential applications in targeted-control drug release and hyperthermia for cancer treatment.
Synthesis of iron oxide nanocubes via microwave-assisted solvolthermal method
Jiang,Wang, Ch.M.,Fu,Liu
, p. L31-L33 (2010)
Iron oxide nanocubes were prepared by thermal decomposition of iron oleate complex in the presence of oleic acid via microwave-assisted solvolthermal method, followed by Ostwald ripening procedures. X-ray powder diffraction and transmission electron microscopy were used to characterize the structure and morphology of the products. The results revealed that the primary nanoparticles synthesized by microwave heating were low crystalline spheres with an average diameter of about 6 nm. After aging at 180°C, these iron oxides transform to crystalline a-Fe2O3 and trace amount of Fe 3O4. The influence of aging time on the size and morphology of a-Fe2O3 nanocrystals was studied. Room temperature magnetization curves measured to study the magnetic properties of as-synthesized nanoparticles.
Alumina-supported iron oxide nanoparticles as Fischer-Tropsch catalysts: Effect of particle size of iron oxide
Park, Jo-Yong,Lee, Yun-Jo,Khanna, Pawan K.,Jun, Ki-Won,Bae, Jong Wook,Kim, Young Ho
, p. 84 - 90 (2010)
The Fischer-Tropsch synthesis of unpromoted and nano-sized iron oxide supported on δ-Al2O3 was investigated using a fixed-bed reactor. The catalysts prepared from pre-synthesized iron oxide with varying particle size (2-12 nm) showed much higher catalytic activities than the one prepared by using conventional impregnation method. The best results for CO conversion were obtained when the catalyst had Fe particle size of 6.1 nm. With an increase in particle size, the reduction degree and C5+ selectivity was increased, whereas CH4 selectivity and the uptake of adsorbed CO were decreased. Turnover frequency (TOF) at 300 °C was increased from 0.02 to 0.16 s-1 when d(Fe0) was increased from 2.4 to 6.2 nm, and then it remains almost constant up to a particle size of 11.5 nm. Particle sizes of prepared iron oxide were analyzed by XRD and TEM, and the reduction behaviors of Fe/Al2O3 catalysts were studied by H2-TPR. The effective iron size, metal dispersion and reduction degree of Fe/Al2O3 catalysts were measured by CO chemisorption and O2 titration.
Size and doping effects on the improvement of the low-temperature magnetic properties of magnetically aligned cobalt ferrite nanoparticles
Knobel, Marcelo,Moscoso-Londo?o, Oscar,Muraca, Diego,Rivas-Rojas, Patricia C.,Socolovsky, Leandro M.,Tancredi, Pablo
, (2021/11/01)
The macroscopic magnetic behavior of nanoparticulated systems is the result of several contributions, ranging from the intrinsic structural properties of the nanoparticles to their spatial arrangement within the material. Unravelling and understanding these influences is an important task to produce nano-systems with improved properties for specific technological applications. In this work we study how the magnetic behavior of a set of magnetically hard nanoparticles can be improved by the modification of the sample arrangement (either randomly or magnetically oriented) and the nature of the enclosing matrices. At first, we employed a hot-injection, continuous growth strategy to synthesize non-stoichiometric cobalt ferrite (CoxFe3?xO4) nanoparticles. We prepared five batches of hydrophobic, oleate-coated samples, with mean diameters of 8 nm, 12 nm, 16 nm and variable Co-to-Fe proportions. The structural characterization confirms that the nanoparticles have a spinel-type monocrystalline structure and that the Co and Fe ions are homogenously distributed within the system. The magnetic properties of the nanoparticles were measured by DC magnetometry, and we found that the strategy used in this work to create a system of magnetically oriented nanoparticles can lead to a significant remanence and coercive field enhancement at low temperatures when compared with randomly oriented and fixed systems. The modification of the magnetic properties was detected in the five batches of samples, but the strength of the enhancement depends on both size and composition of the nanoparticles. Indeed, for the “hardest” samples the coercive field of the magnetically oriented systems reached values of around 30 kOe (3 T), which represents a 50% increase regarding the randomly oriented system and are among the highest reported to date for a set of Fe and Co oxide nanoparticles.
Multimodal therapies: Glucose oxidase-triggered tumor starvation-induced synergism with enhanced chemodynamic therapy and chemotherapy
Cheng, Kaiwu,Ling, Chuxuan,Gu, Dihai,Gao, Zhiguo,Li, Yaojia,An, Peijing,Zhang, Yu,You, Chaoqun,Zhang, Rui,Sun, Baiwang
, p. 1524 - 1536 (2020/02/04)
A tumor microenvironment is distinct from normal tissue cells in characteristic physiochemical conditions, based on which we can design tumor-specific therapy modalities. Herein, we introduce a concept of multimodal therapies, which integrates the characteristics of each therapy modality for efficient tumor therapy: tumor starvation-triggered synergism with enhanced chemodynamic therapy and activated chemotherapy. Fe3O4 nanoparticles (Fenton reaction catalysts) and a hypoxic prodrug tirapazamine (TPZ) were loaded in mesoporous silica nanoparticles (MSN) and GOX was grafted onto its surface, which was designed and fabricated for sequential multimodal therapies. Logically, glucose oxidase (GOX) deprived tumor cells of nutrients (glucose and oxygen) for starvation therapy and tumorous abnormality amplifications (elevated acidity, exacerbated hypoxia, and increased H2O2) were amplified by the GOX-driven oxidation reaction simultaneously. Specifically, elevated acidity could accelerate the release of iron ions and enhanced Fenton reaction efficiency. Associated with increased H2O2, an elevated ROS level was detected, which enhanced the chemodynamic therapy. Exacerbated hypoxia activated the hypoxic prodrug TPZ for tumor-specific chemotherapy programmatically. Particularly, via integrating starvation therapy, enhanced chemodynamic therapy, and activated chemotherapy, the sequential multimodal therapies were specifically designed for the tumor microenvironment and achieved effective abnormality amplifications and high therapeutic efficacy.
