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1.
Different phosphates and phosphonates have shown excellent coating ability toward magnetic nanoparticles, improving their stability and biocompatibility which enables their biomedical application. The magnetic hyperthermia efficiency of phosphates (IDP and IHP) and phosphonates (MDP and HEDP) coated Fe3O4 magnetic nanoparticles (MNPs) were evaluated in an alternating magnetic field. For a deeper understanding of hyperthermia, the behavior of investigated MNPs in the non-alternating magnetic field was monitored by measuring the transparency of the sample. To investigate their theranostic potential coated Fe3O4-MNPs were radiolabeled with radionuclide 177Lu. Phosphate coated MNPs were radiolabeled in high radiolabeling yield (>?99%) while phosphonate coated MNPs reached maximum radiolabeling yield of 78%. Regardless lower radiolabeling yield both radiolabeled phosphonate MNPs may be further purified reaching radiochemical purity of more than 95%. In vitro stabile radiolabeled nanoparticles in saline and HSA were obtained. The high heating ability of phosphates and phosphonates coated MNPs as sine qua non for efficient in vivo hyperthermia treatment and satisfactory radiolabeling yield justifies their further research in order to develop new theranostic agents. 相似文献
2.
Many liposomal drug carriers have shown great promise in the clinic. To ensure the efficient preclinical development of drug-loaded liposomes, the drug retention and circulation properties of these systems should be characterized. Iron oxide (Fe 3O 4) magnetic nanoparticles (MNPs) are used as T2 contrast agents in magnetic resonance imaging (MRI). Gold nanoclusters (GNCs) contain tens of atoms with subnanometer dimensions; they have very low cytotoxicity and possess superb red emitting fluorescent properties, which prevents in vivo background autofluorescence. The aim of this study was to develop dual imaging, nanocomposite, multifunctional liposome drug carriers (Fe 3O 4-GNCs) comprising MNPs of iron oxide and GNCs. First, MNPs of iron oxide were synthesized by co-precipitation. The MNP surfaces were modified with amine groups using 3-aminopropyltriethoxysilane (APTES). Second, GNCs were synthesized by reducing HAuCl 4·3H 2O with NaBH4 in the presence of lipoic acid (as a stabilizer and nanosynthetic template). The GNCs were grown by adsorption onto particles to control the size and stability of the resultant colloids. Subsequently, dual Fe 3O 4-GNCs imaging probes were fabricated by conjugating the iron oxide MNPs with the GNCs via amide bonds. Finally, liposome nanocarriers were used to enclose the Fe 3O 4-GNCs in an inner phase (liposome@Fe 3O 4-GNCs) by reverse phase evaporation. These nanocarriers were characterized by dynamic light scattering (DLS), fluorescence spectroscopy, X-ray diffraction (XRD), transmission electron microscopy (TEM), Fourier transform infrared (FT-IR) spectrophotometry, superconducting quantum interference device (SQUID), nuclear magnetic resonance (NMR) imaging and in vivo imaging systems (IVIS). These multifunctional liposomal drug delivery systems with dual probes are expected to prove useful in preclinical trials for cancer diagnosis and therapy. 相似文献
3.
The evaluation of the toxicity of magnetic nanoparticles (MNPs) has attracted much attention in recent years. The current study aimed to investigate the cytotoxic effects of Fe 3O 4, oleic acid-coated Fe 3O 4 (OA-Fe 3O 4), and carbon-coated Fe (C-Fe) nanoparticles on human hepatoma BEL-7402 cells and the mechanisms. WST-1 assay demonstrated that the cytotoxicity of three types of MNPs was in a dose-dependent manner. G1 (Fe 3O 4 and OA-Fe 3O 4) phase and G2 (C-Fe) phase cell arrests and apoptosis induced by MNPs were detected by flow cytometry analysis. The increase in apoptosis was accompanied with the Bax over-expression, mitochondrial membrane potential decrease, and the release of cytochrome C from mitochondria into cytosol. Moreover, apoptosis was further confirmed by morphological and biochemical hallmarks, such as swollen mitochondria with lysing cristae and caspase-3 activation. Our results revealed that certain concentrations of the three types of MNPs affect BEL-7402 cells viability via cell arrest and inducing apoptosis, and the MNPs-induced apoptosis is mediated through the mitochondrial-dependent pathway. The influence potency of MNPs observed in all experiments would be: C-Fe > Fe 3O 4 > OA-Fe 3O 4. 相似文献
4.
Magnetic polyurethane rigid foam nanocomposites were synthesized by incorporation of surface functionalized iron oxide nanoparticles with 3‐aminopropyltriethoxysilane (APTS). Magnetite nanoparticles (MNPs) and Fe 3O 4@APTS were synthesized via co‐precipitation and sol–gel methods, respectively. The main purpose of the surface modification of MNPs was the formation of hydrogen bond between amino groups of Fe 3O 4@APTS with the urethane groups to improve magnetic and thermal properties of the nanocomposites. The effect of different amounts of Fe 3O 4@APTS on the thermal and magnetic behavior of resultant nanocomposite was investigated and the optimum percentage of nanostructure in foam formulation was defined. POLYM. COMPOS., 38:877–883, 2017. © 2015 Society of Plastics Engineers 相似文献
5.
This short tutorial review highlights the advance in high temperature solution phase chemical synthesis of monodisperse magnetic nanoparticles (MNPs), especially iron oxide NPs, as contrast enhancement agents for cancer detection by magnetic resonance imaging (MRI). It introduces briefly the unique nanomagnetism of MNPs required for MRI. It then summarizes some typical methods used to prepare monodisperse Fe 3O 4 and ferrite MFe 2O 4 MNPs from high temperature organic phase reaction with controlled magnetic properties. It further outlines the chemistry used to make these MNPs biocompatible and target-specific. Finally it presents two examples to demonstrate the MNP control achieved from chemical synthesis for sensitive detection of cancer. 相似文献
6.
Superparamagnetic Fe 3O 4 nanoparticles (MNPs) were functionalized by modified cellulose. The modified cellulose was synthesized through bromoacetylation of cellulose (BACell) followed by the substitution of sodium azide to form BACell-N 3. The remaining methylene bromide groups on BACell-N 3 was further reacted with the MNPs to form Fe 3O 4/Cell-N 3. Then propargyl alcohol (PA) was immobilized on the azide-terminated Fe 3O 4 nanoparticles through copper (I)-catalyzed azide-alkyne cycloaddition (click reaction) to form Fe 3O 4/Cell/TAA nanoparticles. Doxorubicin (DOX) was loaded on prepared nanoparticles and release profiles of the DOX as a model drug from the Fe 3O 4/Cell/TAA nanoparticles and its loading capacity were determined by UV–Vis absorption at λ max 483?nm. 相似文献
7.
A novel design of antibacterial and magnetic halloysite nanotubes loaded with Ag and Fe 3O 4 was reported. In detail, magnetic nanoparticles (Fe 3O 4) were immobilized on the surface of halloysite nanotubes (HNTs) via electrostatic adsorption (termed as HNTs/Fe 3O 4). The magnetic HNTs/Fe 3O 4 was then modified by polydopamine to in-situ grow Ag nanoparticles by a redox reaction, forming a composite nanostructure of HNTs/Fe 3O 4@Ag. The HNTs/Fe 3O 4@Ag was incorporated into poly-l-lactic acid (PLLA) scaffold fabricated via selective laser sintering, with the intent to endow the scaffold with robust antibacterial function and favorable cell activity. The results showed that the released Ag + from the scaffold significantly against E. coli activity, with bacterial inhibition rate above 99%. Moreover, ion release behavior showed a scaffold enable to sustain release Ag + over 28 days. Furthermore, Fe 3O 4 nanoparticles constructed magnetic microenvironment greatly enhanced cell activity and promoted cell proliferation. In addition, tensile strength of the scaffold increased by 52.9% compared with PLLA scaffold. These positive results suggested that the HNTs/Fe 3O 4@Ag nanostructure possessed potential in facilitating bone repair. 相似文献
8.
A novel biodegradable magnetic‐sensitive shape memory poly(?‐caprolactone) nanocomposites, which were crosslinked with functionalized Fe 3O 4 magnetic nanoparticles (MNPs), were synthesized via in situ polymerization method. Fe 3O 4 MNPs pretreated with γ‐(methacryloyloxy) propyl trimethoxy silane (KH570) were used as crosslinking agents. Because of the crosslinking of functionalized Fe 3O 4 MNPs with poly(?‐caprolactone) prepolymer, the properties of the nanocomposites with different content of functionalized Fe 3O 4 MNPs, especially the mechanical properties, were significantly improved. The nanocomposites also showed excellent shape memory properties in both 60 °C hot water and alternating magnetic field ( f = 60, 90 kHz, H = 38.7, 59.8 kA m ?1). In hot water bath, all the samples had shape recovery rate ( Rr) higher than 98% and shape fixed rate ( Rf) nearly 100%. In alternating magnetic field, the Rr of composites was over 85% with the highest at 95.3%. In addition, the nanocomposites also have good biodegradability. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 45652. 相似文献
9.
The interforce between the magnetic composite forward osmosis (FO) membranes and the magnetic draw solution was proposed to reduce the internal concentration polarization (ICP) of FO process, and realized the synergetic permeability improvement of resultant FO membranes. The key factor was the successful fabrication of the Fe 3O 4 magnetic nanoparticles (MNPs) with small‐size and narrow distribution via co‐precipitation method. The cellulose triacetate (CTA) magnetic composite FO membranes were fabricated using Fe 3O 4 as additive via in situ interfacial polymerization, and named CTA‐Fe 3O 4. Dynamic light scattering (DLS) and zeta results showed that the coated sodium oleate on the MNPs explained their reducing aggregation and the stability of various pHs. The MNPs' surface segregation during demixing process resulted in the improvement of hydrophilicity, Fe content and roughness of resultant CTA‐Fe 3O 4 composite FO membranes. Furthermore, the in situ interfacial polymerization resulted in the formation of the polyamide selective layer, and the CTA‐Fe 3O 4 membrane's N content was 11.02% to 11.12%. The permeability properties (FO and pressure retarded osmosis modules) were characterized using 1.0 M NaCl and 100 mg/L Fe 3O 4 as draw solutions, respectively. The results indicated that the higher concentration of MNPs supplied more interforce and better FO permeability properties. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 44852. 相似文献
10.
In order to develop multifunctional nanofibers, the electrical conductivity and magnetic properties of Fe 3O 4/carbon composite nanofibers have been examined. Polyacrylonitrile (PAN) is used as a matrix to produce magnetic composite nanofibers containing different amounts of magnetite (Fe 3O 4) nanoparticles. Electrospun composite nanofibers were thermally treated to produce electrically conductive and magnetically permeable composite carbon nanofibers. The composite nanofibers were characterized using scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffractometry (XRD), Raman spectroscopy, four-point probe and Superconducting Quantum Interference Device (SQUID). Uniform nanofibers were obtained with successful transferring of magnetic properties of Fe 3O 4 into the as-spun composite nanofibers. The electromagnetic properties were tuned by adjusting the amount of Fe 3O 4 in the matrix and carbonization process. The electrical conductivity, magnetic moment and also magnetic hysteresis rise up by adding Fe 3O 4 and increasing carbonization temperature. The high surface area provided by the ultrafine fibrous structures, the flexibility and tuneable electromagnetic properties are expected to enable the expansion of the design options for a wide rage of electronic devices. 相似文献
11.
A magnetic nanocomposite of citric‐acid‐functionalized graphene oxide was prepared by an easy method. First, citric acid (CA) was covalently attached to acyl‐chloride‐functionalized graphene oxide (GO). Then, Fe 3O 4 magnetic nanoparticles (MNPs) were chemically deposited onto the resulting adsorbent. CA, as a good stabilizer for MNPs, was covalently attached to the GO; thus MNPs were adsorbed much more strongly to this framework and subsequent leaching decreased and less agglomeration occurred. The attachment of CA onto GO and the formation of the hybrid were confirmed by Fourier transform infrared spectroscopy, scanning electron microscopy, X‐ray diffraction spectrometry and transmission electron microscopy. The specific saturation magnetization of the magnetic CA‐grafted GO (GO‐CA‐Fe 3O 4) was 57.8 emu g ?1 and the average size of the nanoparticles was found to be 25 nm by transmission electron microscopy. The magnetic nanocomposite was employed as an adsorbent of methylene blue from contaminated water. The adsorption tests demonstrated that it took only 30 min to attain equilibrium. The adsorption capacity in the concentration range studied was 112 mg g ?1. The GO‐CA‐Fe 3O 4 nanocomposite was easily manipulated in an external magnetic field which eases the separation and leads to the removal of dyes. Thus the prepared nanocomposite has great potential in removing organic dyes. © 2014 Society of Chemical Industry 相似文献
12.
It is demonstrated that functionalization of single-wall carbon nanotubes (SWCNTs) can be carried out using simple chlorosilane chemistry, which allows coupling of the SWCNTs with external chemical species. As a result, organic polymers and magnetically iron oxide-in-silica nanoparticles are specifically bonded onto SWCNTs. It is also found that the SWCNTs functionalized with long PEG chains greatly enhance dispersion of the carbon structure in water. Furthermore, the SWCNT-COO-Si(Fe 3O 4@SiO 2) can be quickly separated and redispersed from their aqueous colloid with the application of external magnetic field. 相似文献
13.
L-cysteine functionalized Fe 3O 4 magnetic nanoparticles (Cys–Fe 3O 4 MNPs) were continuously fabricated by a simple high-gravity reactive precipitation method combined with surface modification through a novel impinging stream-rotating packed bed with the assistance of sonication. The obtained Cys–Fe 3O 4 MNPs was characterized by XRD, TEM, FTIR, TGA and VSM, and further used for the removal of heavy metal ions from aqueous solution. The influence of pH values, contact time and initial metal concentration on the adsorption efficiency were investigated. The results revealed that the adsorption of Pb(II) and Cd(II) were pH dependent process, and the pH 6.0 was found to be optimum condition. Moreover, the adsorption kinetic for Cys–Fe 3O 4 MNPs followed the mechanism of the pseudo-second order kinetic model, and their equilibrium data were fitted with the Langmuir isothermal model well. The maximum adsorption capacities calculated from Langmuir equation were 183.5 and 64.35 mg g −1 for Pb(II) and Cd(II) at pH 6.0, respectively. Furthermore, the adsorption and regeneration experiment showed there was about 10% loss in the adsorption capacity of the as-prepared Cys–Fe 3O 4 MNPs for heavy metal ions after 5 times reuse. All the above results provided a potential method for continuously preparing recyclable adsorbent applied in removing toxic metal ions from wastewater through the technology of process intensification. 相似文献
14.
A nanometric hybrid system consisting of a Fe 3O 4 magnetic nanoparticles modified through the growth of Fe-based Metal-organic frameworks of the MIL (Materials Institute Lavoiser) was developed. The obtained system retains both the nanometer dimensions and the magnetic properties of the Fe 3O 4 nanoparticles and possesses increased the loading capability due to the highly porous Fe-MIL. It was tested to load, carry and release temozolomide (TMZ) for the treatment of glioblastoma multiforme one of the most aggressive and deadly human cancers. The chemical characterization of the hybrid system was performed through various complementary techniques: X-ray-diffraction, thermogravimetric analysis, FT-IR and X-ray photoelectron spectroscopies. The nanomaterial showed low toxicity and an increased adsorption capacity compared to bare Fe 3O 4 magnetic nanoparticles (MNPs). It can load about 12 mg/g of TMZ and carry the drug into A172 cells without degradation. Our experimental data confirm that, after 48 h of treatment, the TMZ-loaded hybrid nanoparticles (15 and 20 μg/mL) suppressed human glioblastoma cell viability much more effectively than the free drug. Finally, we found that the internalization of the MIL-modified system is more evident than bare MNPs at all the used concentrations both in the cytoplasm and in the nucleus suggesting that it can be capable of overcoming the blood-brain barrier and targeting brain tumors. In conclusion, these results indicate that this combined nanoparticle represents a highly promising drug delivery system for TMZ targeting into cancer cells. 相似文献
15.
Fe 3O 4 magnetic nanoparticles (MNPs) were prepared by the coprecipitation of Fe 2+ and Fe 3+ using ammonium hydroxide (NH 4OH) as precipitating agent. Transmission electronic microscopy (TEM) showed that the particle-size is around 10 nm. X-ray powder diffraction (XRD) indicated the sole existence of inverse cubic spinel phase of Fe 3O 4. The surface of MNPs was coated with oleate sodium as the primary layer and polyethylene glycol 4000 (PEG-4000) as the secondary layer to improve the stability of water-based ferrofluids (FFs). The dosages of oleate sodium and PEG-4000 were found to have an important effect on increasing the solid content. Gouy magnetic balance showed that the saturation magnetization could be as high as 1.44 × 10 5 A/m. Laser particle-size analyzer determined the aggregate size in FFs. The Fe 3O 4 MNPs did not change through the preparation of FFs. Differential scanning calorimetry-thermogravimetry (DSC-TG) and Fourier transform infrared spectroscopy (FT-IR) analysis showed existence of two distinct surfactants on the particle surface. The concentrated and diluted FFs were characterized by UV-vis spectrophotometer and excellent stability was found. The rheological measurements indicated that viscosity increased with the increase of solid content and applied magnetic field, but decreased with the increase of temperature. The FFs showed the non-Newtonian behavior of shear-thinning when the solid content was high. The mechanical properties of polyvinylalcohol (PVA) thin film can be greatly improved by adding FFs. 相似文献
16.
Electrospun polyacrylonitrile (PAN)‐based carbon composite fibers embedded with magnetic nanoparticles have been developed as materials for electromagnetic wave absorption. The nanocomposite fibers were prepared by electrospinning from a dispersion of magnetite (Fe 3O 4) nanoparticles stabilized by L ‐glutamic acid in a solution of PAN and N, N‐dimethyl formamide. The Fe 3O 4‐embedded PAN nanofibers were stabilized at 270°C in air and carbonized at 800°C in nitrogen. The Fe 3O 4 nanoparticles were crystalline with a particle size of about 7 nm, most of which was reduced to Fe 3C with agglomerates of up to 50 nm diameter in the carbon fibers. The carbon morphology was mostly disordered, but exhibited a layered graphitic structure in the vicinity of the nanoparticles. The carbon composite fiber exhibited ferromagnetic behavior, and the induced magnetic saturation per unit mass of fibers increased with increasing Fe 3O 4 content in the precursor. The complex relative dielectric permittivity was tuned by adjusting the amount of Fe 3O 4 in the carbon fiber precursor. With increasing Fe 3O 4 content, good electromagnetic wave absorption characteristics were observed below 6 GHz, even for samples with fiber loadings as low as 5 wt %. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013 相似文献
17.
A simple, fast, and economic methodology to fabricate a highly efficient superparamagnetic Fe 3O 4/hydroxyapatite nanocomposite (MHAP) was successfully developed. Hydroxyapatite was functionalized with magnetite nanoparticles through coprecipitation‐assisted microwave processes to improve the magnetic properties. The synthesized magnetic hybrid adsorbent matrix was investigated by different methods. Transmission electron microscopy demonstrated a good impregnation of Fe 3O 4 on the hydroxyapatite matrix with uniform morphology. Magnetic hysteresis measurement revealed that MHAP nanocomposites exhibit excellent strong, soft‐magnetic properties. The synergistic effect was an evidence for iron and manganese ion removal, enlightening their potentialities in treatment of polluted ground water. 相似文献
18.
In this work, a novel water dispersible polyurethane (WDPU) was synthesized from the reaction of hydroxyl-terminated polybutadiene (HTPB), 2,2 bis(hydroxymethyl) propionic acid (DMPA), and 1,5-naphthalene diisocyanate (NDI) and its magnetic nanocomposites were prepared by incorporation of modified Fe 3O 4 by 3-aminopropyltriethoxysilane (Fe 3O 4@APTS) nanoparticles (0.5, 1.5, and 3 wt%) via in situ polymerization method. Use of NDI as a high melting point diisocyanate by having the rigid naphthalene structure imparts physical strength as well as thermal stability to the resulted polyurethane. The synthesized WDPU based on NDI was characterized by using Fourier transform infrared spectroscopy (FTIR) technique. In addition, the morphology, mechanical, and magnetic features of the prepared polyurethane nanocomposites were investigated by X-ray diffraction (XRD), dynamic light scattering (DLS), transmission electron microscopy (TEM), atomic force microscopy (AFM), magnetic force microscopy (MFM), thermogravimetry analysis (TGA), dynamic mechanical thermal analysis (DMTA), and vibrating sample magnetometer (VSM) methods, respectively. Data from DLS experiment showed that the average particles size of the WDPU nanocomposites increased by increasing the nanoparticle contents in comparison with bare WDPU. AFM and MFM analyses indicated that the magnetic nanoparticles (MNPs) were well dispersed in the polyurethane matrices via the formation of covalent bonding between the functionalized magnetic nanoparticles and polymer chains. TGA results demonstrated that adding MNPs increased the temperature of the thermal degradation of the polyurethane nanocomposite. VSM analysis showed that the super paramagnetic behavior of the prepared nanocomposites depended on the Fe 3O 4@APTS nanoparticle content, as well. 相似文献
19.
In this paper, we investigated the functional imaging properties of magnetic microspheres composed of magnetic core and CdTe quantum dots in the silica shell functionalized with folic acid (FA). The preparation procedure included the preparation of chitosan-coated Fe 3O 4 nanoparticles (CS-coated Fe 3O 4 NPs) prepared by a one-pot solvothermal method, the reaction between carboxylic and amino groups under activation of NHS and EDC in order to obtain the CdTe-CS-coated Fe 3O 4 NPs, and finally the growth of SiO 2 shell vent the photoluminescence (PL) quenching via a Stöber method (Fe 3O 4-CdTe@SiO 2). Moreover, in order to have a specific targeting capacity, the magnetic and fluorescent bifunctional microspheres were synthesized by bonding of SiO 2 shell with FA molecules via amide reaction (Fe 3O 4-CdTe@SiO 2-FA). The morphology, size, chemical components, and magnetic property of as-prepared composite nanoparticles were characterized by ultraviolet-visible spectroscopy, fluorescent spectroscopy, Fourier transform infrared spectroscopy (FTIR), X-ray powder diffraction (XRD), scanning transmission electron microscopy (SEM), transmission electron microscopy (TEM), thermogravimetric analysis (TGA), and vibrating sample magnetometer (VSM), respectively. The results show that the magnetic and fluorescent bifunctional microspheres have strong luminescent which will be employed for immuno-labeling and fluorescent imaging of HeLa cells. 相似文献
20.
Porous Fe 3O 4/C microspheres, which were Fe 3O 4 nanocrystals (~8?nm) embedded in an open nanostructured carbon network, were successfully synthesized via a facile hydrothermal process. The porous Fe 3O 4/C microspheres possessed many distinct attributes that facilitate efficient broadband electromagnetic wave absorption (EMWA). EMWs were attenuated through multiple reflections and absorption in the 3D interconnected porous structure of the microspheres; these processes collectively improved the interaction between the EMWs and the absorber. Additionally, the carbon network and embedded Fe 3O 4 nanoparticles caused significant dielectric losses and magnetic losses, respectively, which also enhanced EMWA. The EMWA characteristics of the microspheres could be precisely tuned via changing the carbon content to achieve optimized impedance matching. Porous Fe 3O 4/C microspheres with a 71.5?wt% carbon content displayed particularly impressive EMWA properties: a maximum reflection loss (RL) value of ??31.75 across broad band frequencies in the range of 7.76–12.88?GHz (RL < ?10?dB) at an absorber thickness of 3.0?mm. These excellent EMWA properties may be attributed to both dielectric loss (carbon) and magnetic loss (Fe 3O 4). Additionally, the 3D interconnected porous structure of the Fe 3O 4/C microspheres is especially favorable for impedance matching. 相似文献
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