Iron Oxide Core Research Articles

Toxicology study for magnetic injection of prednisolone into the rat cochlea

This paper investigates the safety of a novel ‘magnetic injection’ method of delivering therapy to the cochlea, in a rodent model. In this method of administration, a magnetic field is employed to actively transport drug-eluting superparamagnetic iron-oxide core nanoparticles into the cochlea, where they then release their drug payload (we delivered the steroid prednisolone). Our study design and selection of control groups was based on published regulatory guidance for safety studies that involve local drug delivery. We tested for both single and multiple delivery doses to the cochlea, and found that magnetic delivery did not harm hearing. There was no statistical difference in hearing between magnetically treated ears versus ears that received intra-tympanic steroid (a mimic of a standard-of-care for sudden sensorineural hearing loss), both 2 and 30 days after treatment. Since our treatment is local to the ear, the levels of steroid and iron circulating systemically after our treatment were low, below mass-spectrometry detection limits for the steroid and no different from normal for iron. No adverse findings were observed in ear tissue histopathology or in animal gross behavior. At 2 and 30 days after treatment, inflammatory changes examined in the ear were limited to the middle ear, were very mild in severity, and by day 90 there was ongoing and almost complete reversibility of these changes. There were no ear tissue scarring or hemorrhage trends associated with magnetic delivery. In summary, after conducting a pre-clinical safety study, no adverse safety issues were observed.

Plantain Peel Mediated Green Synthesis Iron Oxide Nanoparticles, Surface Functionalization, and Them Performance towards Methylene Blue and Methyl Orange Dye Removal

Currently, green synthesis approach is used as the biocompatible, eco-friendly, and sustainable alternative of conventional approaches to synthesize iron oxide nanoparticles. In this work, magnetic iron oxide nanoparticles were synthesized by using plantain peel extract via green and biogenic approach. The surface of green synthesized iron oxide nanoparticles was functionalized to increase the stability of the nanoparticles and maintain the coexisting of both magnetic and catalytic property of the nanoparticles at the same time. Two kinds of surface functionalization structures were synthesized in this study, included silica core-iron oxide shell nanoparticles and silica core-PDDA polymerized iron oxide shell nanoparticles. The main concern of this study is the performance of bare and surface functionalized green synthesized nanoparticles. Methylene blue and methyl orange dyes were used as the model of dye removal test to indicate the feasibility of the synthesized nanocomposites. In summary, surface functionalized nanocomposites achieved higher dye removal efficiency than bare green synthesized iron oxide nanoparticles in both the methylene blue and methyl orange degradation test. Methylene blue dye was removed in higher rate than methyl orange dye due to the presence of negatively charged iron oxide nanoparticles with both the adsorptive and catalytic properties. At last, the components present in plantain peel extract were confirmed by using Fourier Transform Infrared Spectroscopy.

Stealth Nanoparticles Grafted with Dense Polymer Brushes Display Adsorption of Serum Protein Investigated by Isothermal Titration Calorimetry.

Core–shell nanoparticles receive much attention for their current and potential applications in life sciences. Commonly, a dense shell of hydrated polymer, a polymer brush, is grafted to improve colloidal stability of functional nanoparticles and to prevent protein adsorption, aggregation, cell recognition, and uptake. Until recently, it was widely assumed that a polymer brush shell indeed prevents strong association of proteins and that this leads to their superior “stealth” properties in vitro and in vivo. We show using T-dependent isothermal titration calorimetry on well-characterized monodisperse superparamagnetic iron oxide nanoparticles with controlled dense stealth polymer brush shells that “stealth” core–shell nanoparticles display significant attractive exothermic and enthalpic interactions with serum proteins, despite having excellent colloidal stability and negligible nonspecific cell uptake. This observation is at room temperature shown to depend only weakly on variation of iron oxide core diameter and type of grafted stealth polymer: poly(ethylene glycol), poly(ethyl oxazoline), poly(isopropyl oxazoline), and poly(N-isopropyl acrylamide). Polymer brush shells with a critical solution temperature close to body temperature showed a strong temperature dependence in their interactions with proteins with a significant increase in protein binding energy with increased temperature. The stoichiometry of interaction is estimated to be near 1:1 for PEGylated nanoparticles and up to 10:1 for larger thermoresponsive nanoparticles, whereas the average free energy of interaction is enthalpically driven and comparable to a weak hydrogen bond.

Rapid Detection of Escherichia coli O157:H7 in Fresh Lettuce Based on Localized Surface Plasmon Resonance Combined with Immunomagnetic Separation

This study presents a method for rapid detection of Escherichia coli O157:H7 in fresh lettuce based on the properties of target separation and localized surface plasmon resonance of immunomagnetic nanoparticles. The multifunctional immunomagnetic nanoparticles enabling simultaneous separation and detection were prepared by synthesizing magnetic nanoparticles (ca. 10 nm in diameter) composed of an iron oxide (Fe3O4) core and gold shell and then conjugating these nanoparticles with the anti- E. coli O157:H7 antibodies. The application of multifunctional immunomagnetic nanoparticles for detecting E. coli O157:H7 in a lettuce matrix allowed detection of the presence of <1 log CFU mL-1 without prior enrichment. In contrast, the detection limit of the conventional plating method was 2.74 log CFU mL-1. The method, which requires no preenrichment, provides an alternative to conventional microbiological detection methods and can be used as a rapid screening tool for a large number of food samples.

Yerba Mate applications: Magnetic response of powders and colloids of iron oxide nanoparticles coated with Ilex paraguariensis derivatives

A co-precipitation synthesis method was used to obtain iron oxide nanoparticles coated with Yerba Mate (Ilex paraguariensis) extract. These particles have a core–shell structure with the iron oxide phase surrounded by an organic shell provided by an organic component which come from the Yerba Mate extract.Obtained nanoparticles were exhaustively characterized as powders and in aqueous colloidal suspensions using several techniques such as TEM, XRD, SAXS, TGA, ATR-FTIR, Raman and XPS spectroscopy, magnetic moment measurement and specimen ac susceptibility. All results together show that the obtained particles are single-crystal iron oxide particles with magnetite as the most probable phase. Yerba Mate extract shell mass to iron oxide core mass, mS/mc, could be increased up to 6.2 × 10−2, depending on the synthesis conditions. As a function of mS/mc the crystallite size of the nanoparticles decreased from about 15 nm to 11 nm, while saturation magnetization Ms and coercive field Hc of powders decreased. Ms. diminution was associated to increasing modification of core surface electronic states due to chemical bond of iron in iron oxide to Yerba Mate extract components; on the other hand, coercivity reduction was modelled on the basis of the increasing interparticle separation and dipolar interaction weakening, which occurs as shell thickness grows.Differences between the particle core mean size obtained with TEM, SAXS, XRD and magnetic measurements are observed. The fact that magnetic size was smaller than particle and crystallite sizes was attributed to the existence of intense dipolar interactions. It was found that low field susceptibility in a colloid sample was about 2.5 times that of the powder specimen, a result that shows that demagnetizing effects prevail in the powder specimen, while they may be absent in the colloid due to the larger interparticle mean separation expected in the latter. Analysis of powder and colloid susceptibility was done based on a recently developed model was in agreement with the one performed for the coercive field behaviour.

Smart-Dust-Nanorice for Enhancement of Endogenous Raman Signal, Contrast in Photoacoustic Imaging, and T2-Shortening in Magnetic Resonance Imaging.

Raman microspectroscopy provides chemo-selective image contrast, sub-micrometer resolution, and multiplexing capabilities. However, it suffers from weak signals resulting in image-acquisition times of up to several hours. Surface-enhanced Raman scattering (SERS) can dramatically enhance signals of molecules in close vicinity of metallic surfaces and overcome this limitation. Multimodal, SERS-active nanoparticles are usually labeled with Raman marker molecules, limiting SERS to the coating material. In order to realize multimodal imaging while acquiring the rich endogenous vibronic information of the specimen, a core-shell particle based on "Nanorice", where a spindle-shaped iron oxide core is encapsulated by a closed gold shell, is developed. An ultrathin layer of silica prevents agglomeration and unwanted chemical interaction with the specimen. This approach provides Raman signal enhancement due to plasmon resonance effects of the shell while the optical absorption in the near-infrared spectral region provides contrast in photoacoustic tomography. Finally, T2-relaxation of a magnetic resonance imaging (MRI) experiment is altered by taking advantage of the iron oxide core. The feasibility for Raman imaging is evaluated by nearfield simulations and experimental studies on the primate cell line COS1. MRI and photoacoustics are demonstrated in agarose phantoms illustrating the promising translational nature of this strategy for clinical applications in radiology.

Synthesis and Characterization of Ferromagnetic Fe3O4–ZnO Hybrid Core–Shell Nanoparticles

Room-temperature synthesis of multifunctional core–shell nanostructures with iron oxide (Fe3O4) core and zinc oxide (ZnO) shell is described. High-resolution transmission electron microscopy revealed the occurrence of heteroepitaxial growth of a ZnO shell over the iron oxide nanoparticle core. The formation of the core–shell nanostructure was also evidenced by x-ray diffraction and x-ray photoelectron spectroscopy analyses. The core Fe3O4 nanoparticles exhibited superparamagnetic behavior at room temperature in an externally applied magnetic field. However, magnetic measurements of the core–shell nanoparticles revealed ferromagnetic behavior, originating from defect-induced ferromagnetism in the ZnO shell. The prepared core–shell nanoparticles also exhibited strong photoresponse while retaining ferromagnetic behavior at room temperature.

Nitrogen‐Doped Graphene‐Supported Iron Catalyst for Highly Chemoselective Hydrogenation of Nitroarenes

AbstractA nitrogen‐doped graphene‐supported iron catalyst was used for the first time in the hydrogenation of a series of nitroarenes to give the corresponding amines with excellent activity and chemoselectivity under mild reaction conditions. Physicochemical characterization of the catalyst by transmission electron microscopy, X‐ray diffraction, X‐ray photoelectron spectroscopy, and Mössbauer spectroscopy revealed the formation of iron particles with an iron oxide core and a metallic iron shell that were coated by a few layers of nitrogen‐doped graphene. The unique structure of FeNx/C in the catalyst was proven to contribute to the hydrogenation activity.

Superparamagnetic iron oxide nanoparticles modified with polyethylenimine and galactose for siRNA targeted delivery in hepatocellular carcinoma therapy.

IntroductionA safe and effective in vivo siRNA delivery system is a prerequisite for liver tumor treatment based on siRNA cancer therapeutics. Nanoparticles based on superparamagnetic iron oxide (SPIO) provide a promising delivery system. In this study, we aimed to explore a novel nanoparticle, which is composed of SPIO.Materials and methodsThe particles have a core of iron oxide that is modified by galactose (Gal) and polyethylenimine (PEI), which act as shells, providing targeted delivery of therapeutic siRNA to the liver cancer. Gal-PEI-SPIO nanoparticles were synthesized, and the characteristics of the Gal-PEI-SPIO encapsulated with siRNA were analyzed.ResultsThe particles remained nanoparticles and displayed negligible cytotoxicity when loaded with siRNA. In a serum stability assay, the Gal-PEI-SPIO nanoparticles could shield the siRNA from serum degradation and prolong the half-life of the siRNA in the system. Simultaneously, we found that the mixture could be efficiently taken up by Hepa1–6 cells in a flow cytometry assay. To study the anticancer effect, quantitative polymerase chain reaction and Western blotting were used to validate the silencing efficacy of the complexes in vitro. Subsequently, the nanoparticle mixtures were administered intravenously to tumor-bearing mice to explore the tissue distribution and the effect of the siRNA against cancer. We found that the nanoparticles could provide targeted siRNA delivery, accumulate easily in orthotopic tumors, enhance siRNA accumulation in the tumor tissues for 24 h and protect the siRNA from serum nuclease degradation in comparison with the control group. After these study procedures, the mice were sacrificed, and the tumors were removed to compare the tumor size and analyze the therapeutic effect on tumor growth. The tumor volume and the liver/body weight ratio were significantly reduced in the si-c-Met therapy groups. Additionally, the mRNA levels were also lower than those observed in the controls.ConclusionBased on these results, we concluded that Gal-PEI-SPIO represents a promising and efficient platform for siRNA delivery in tumor therapy.

Selenium and Iron Oxide Nanocomposites for Magnetically-Targeted Anti-Cancer Applications.

Iron oxide nanoparticles (IONP) are already well-established in the medical field due to their ability to improve contrast in magnetic resonance imaging (MRI) and for their external magnetic control in the body. Moreover, selenium has been shown to kill numerous cancer cells at lower concentrations that IONP (e.g., 1 μg/ml). Selenium is a trace mineral of growing interest in cancer treatment since it is an essential nutrient in the human body and can interfere with thiolcontaining proteins necessary for cancer cells to function. For the above reasons, the goal of this in vitro study was to combine the above chemistries for the first time to develop composite nano-vehicles for magnetically targeted cancer therapy. The suggested design was an IONP core, stabilized by chitosan and decorated with selenium. Two different types of IONP cores were produced. This was followed by different chitosan and selenium coating methods. The particles were characterized for size, shape, zeta potential and magnetic properties. Finally, the most promising products were tested for cancer killing properties on MB-231 breast cancer cells. Results of this pioneering study showed that the most promising iron-selenium nanocomposites consisted of an iron oxide core produced by thermal decomposition, followed by a silane ligand exchange, a chitosan coating and selenium decoration. The particles were 5-9 nm in diameter, with a zeta potential of 29.59 mV and magnetic properties of 35.932 emu/g. Moreover, the novel nanoparticles had concentration dependent cancer killing properties. Specifically, after just 1 day of incubation, breast cancer cell viability was reduced to 40.5% in the presence of 1 μg/ml of these composite nanoparticles (and statistically reduced at even 0.1 μg/ml), without using a chemotherapeutic pharmaceutical drug. This is a significant finding since neither chemotherapeutic pharmaceutical drugs, infrared stimulation, nor magnetism were used. In this manner, this study introduces a brand new composite nanoparticle consisting of iron oxide and selenium which should be further studied for a wide range of magnetically targeted anticancer applications.

Oxidative Degradation of Bisphenol A Using Recyclable Nanomaterials

Two types of nanomaterials with promising potential for bisphenol A (BPA) degradation have been synthesized using two simple methods. In the first method (mode 1; M1-MnOX), KMnO4 solution was added to pre-synthesized magnetic iron oxide nanoparticles (MC) under ultrasonic mixing and subsequently, MnSO4 solution was added dropwise to the suspension. In the second method (mode 2; M2-MnOX), the mode of reagent addition was reversed; MnSO4 solution was added to MC under continuous sonication prior to the dropwise addition of KMnO4 solution to the suspension. The nanomaterials were characterized using X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR), and thermogravimetric analysis (TGA). The application of the nanomaterials as reusable magnetic materials for BPA degradation in water was investigated. The M1-MnOX and M2-MnOX, nanomaterials with sizes in the range 10–18 nm, were composed of iron oxide core and amorphous manganese oxide shell. Interestingly, the maximum amount of BPA degraded by M1-MnOX within 48 h was ~1 mg BPA/g wet nanoparticles, which was significantly higher than the amount degraded by M2-MnOX nanoparticles (~0.16 mg BPA/g wet nanoparticles). Furthermore, the M1-MnOX nanoparticles could be efficiently reused four successive times without major loss of degradation activity. These low cost nanomaterials could be easily recovered by magnetic separation and washed for reuse, overcoming both filtration and reuse problems often associated with conventional use of colloidal manganese oxides as sorbents or catalysts.

Block copolymer based novel magnetic mixed matrix membranes-magnetic modulation of water permeation by irreversible structural changes

This contribution focuses on understanding the effect of magnetic field intensity on the performance of novel hydrophilic and hydrophobic mixed matrix membranes (MMMs). The hydrophilic MMMs were made up of polymeric nanoparticles (PNPs) that were synthesized through polymerization-induced self-assembly (PISA) and iron oxide nanoparticles prepared in presence of poly (methacrylic acid)-b-poly quaternized (2-dimethylamino)ethyl methacrylate. The hydrophobic MMMs were prepared by the addition of iron oxide nanoparticles with different surface properties to a linear poly (methacrylic acid)-b-poly (methylmethacrylate) diblock copolymer dissolved in tetrahydrofuran (THF). Three different types of hydrophilic membranes were prepared with polymeric nanoparticles of different morphologies (spherical, vermicular and vesicular). In case of the hydrophobic membranes, six different membranes containing different iron oxide core coated with different stabilizers such as poly (methacrylic acid), quaternized poly(2-dimethylamino)ethyl methacrylate and meso-2,3-dimercaptosuccinic acid were prepared. An external magnetic field with intensity values up to 1.15T was used for the permeation studies and the results were compared with those obtained in the absence of magnetic field. The collected data indicate an increase in the water flux of up to 16% and 29% under the magnetic field for hydrophobic and hydrophilic membranes, respectively. The STEM analyses suggest that the magnetic nanoparticles move within the membrane structure during the application of the magnetic field. This displacement/rearrangement causes constant changes in the membrane structure (structure of the active layer) and consequently on the membrane permeability. These results suggest that the application of the magnetic field could be used as a pretreatment step to obtain high flux membranes.

Core–Shell Fe–Pt Nanoparticles in Ionic Liquids: Magnetic and Catalytic Properties

The reaction of Fe(CO)5 and Pt2(dba)3 in 1-n-butyl-methylimidazolium tetrafluoroborate (BMIm.BF4), hexafluorophosphate (BMIm.PF6), and bis(trifluoromethanesulfonyl)imide (BMIm.NTf2) under hydrogen affords stable magnetic colloidal core–shell nanoparticles (NPs). The thickness of the Pt shell layer has a direct correlation with the water stability of the anion and increases in the order of PF6 > BF4 > NTf2, yielding the metal compositions Pt4Fe1, Pt3Fe2, and Pt1Fe1, respectively. Magnetic measurements give evidence of a strongly enhanced Pauli paramagnetism of the Pt shell and a partially disordered iron-oxide core with diminished saturation magnetization. The obtained Pauli paramagnetism of the Pt shell is 2 orders of magnitude higher than that of bulk Pt, owing to symmetry breaking at the surface and interface, resulting in a strong increase in the density of states at the Fermi level, and thus to enhanced Pauli susceptibility. Moreover, these ultrasmall NPs showed efficient catalytic activity for the di...

Synthesis, Radiolabelling and In Vitro Imaging of Multifunctional Nanoceramics.

Molecular imaging has become a powerful technique in preclinical and clinical research aiming towards the diagnosis of many diseases. In this work, we address the synthetic challenges in achieving lab‐scale, batch‐to‐batch reproducible copper‐64‐ and gallium‐68‐radiolabelled metal nanoparticles (MNPs) for cellular imaging purposes. Composite NPs incorporating magnetic iron oxide cores with luminescent quantum dots were simultaneously encapsulated within a thin silica shell, yielding water‐dispersible, biocompatible and luminescent NPs. Scalable surface modification protocols to attach the radioisotopes 64Cu (t1/2=12.7 h) and 68Ga (t1/2=68 min) in high yields are reported, and are compatible with the time frame of radiolabelling. Confocal and fluorescence lifetime imaging studies confirm the uptake of the encapsulated imaging agents and their cytoplasmic localisation in prostate cancer (PC‐3) cells. Cellular viability assays show that the biocompatibility of the system is improved when the fluorophores are encapsulated within a silica shell. The functional and biocompatible SiO2 matrix represents an ideal platform for the incorporation of 64Cu and 68Ga radioisotopes with high radiolabelling incorporation.

Relating Magnetic Properties and High Hyperthermia Performance of Iron Oxide Nanoflowers

We investigated, in depth, the interrelations among structure, magnetic properties, relaxation dynamics and magnetic hyperthermia performance of magnetic nanoflowers. The nanoflowers are about 39 nm in size, and consist of densely packed iron oxide cores. They display a remanent magnetization, which we explain by the exchange coupling between the cores, but we observe indications for internal spin disorder. By polarized small-angle neutron scattering, we unambiguously confirm that, on average, the nanoflowers are preferentially magnetized along one direction. The extracted discrete relaxation time distribution of the colloidally dispersed particles indicates the presence of three distinct relaxation contributions. We can explain the two slower processes by Brownian and classical Neel relaxation, respectively. The additionally observed very fast relaxation contributions are attributed by us to the relaxation of disordered spins within the nanoflowers. Finally, we show that the intrinsic loss power (ILP, ma...

Photocatalytic hydrogen production using TiO2 coated iron-oxide core shell particles

Photocatalytic water splitting plays a challenging role as it is one of the most important reactions for solving energy, environmental problems and sustainability. Photocatalytic water splitting was improved by using a novel kind of magnetically separable core shell nano photocatalyst TiO2/Fe2O3, prepared by co-precipitation method. It was characterised for particle size (XRD), band gap (UV-DRS), morphology (SEM), particle size (HRTEM), elemental composition (EDS) and electrochemical studies. Photocatalytic splitting of water was examined in tubular reactor of 500 mL capacity with various sacrificial agents viz., methanol, ethanol, acetic acid, lactic acid, EDTA and triethanolamine. To enhance the hydrogen production, various operating parameters viz., effect of sacrificial agents, catalytic dosage, light irradiation and recycle flow rate were optimized. With the optimized operating parameters (0.2 g catalyst dosage, 60 mL/min recycle flow rate, 96 W/m2 light irradiation and EDTA as sacrificial agent) the maximum hydrogen achieved was 2700 μmol/h for the quantum yield of 3.86% at 550 nm. The reusability studies were conducted and the TiO2 coated Fe2O3 core shell particles were found to be stable than the plain TiO2 nano particles. Effective charge transfer from TiO2 to Fe2O3 and the suppression of e−/h+ pair recombination attributed significant enhancement in photoactivity, thereby increasing the hydrogen production.

Fucoidan Prolongs the Circulation Time of Dextran-Coated Iron Oxide Nanoparticles.

The magnetic properties and safety of dextran-coated superparamagnetic iron oxide nanoparticles (SPIONs) have facilitated their clinical use as MRI contrast agents and stimulated research on applications for SPIONs in particle imaging and magnetic hyperthermia. The wider clinical potential of SPIONs, however, has been limited by their rapid removal from circulation via the reticuloendothelial system (RES). We explored the possibility of extending SPION circulatory time using fucoidan, a seaweed-derived food supplement, to inhibit RES uptake. The effects of fucoidan on SPION biodistribution were evaluated using ferucarbotran, which in its pharmaceutical formulation (Resovist) targets the RES. Ferucarbotran was radiolabeled at the iron oxide core with technetium-99m (99mTc; t1/2 = 6 h) or zirconium-89 (89Zr; t1/2 = 3.3 days). Results obtained with 99mTc-ferucarbotran demonstrated that administration of fucoidan led to a 4-fold increase in the circulatory half-life (t1/2 slow) from 37.4 to 150 min (n = 4; P < 0.0001). To investigate whether a longer circulatory half-life could lead to concomitant increased tumor uptake, the effects of fucoidan were tested with 89Zr-ferucarbotran in mice bearing syngeneic subcutaneous (GL261) tumors. In this model, the longer circulatory half-life achieved with fucoidan was associated with a doubling in tumor SPION uptake (n = 5; P < 0.001). Fucoidan was also effective in significantly increasing the circulatory half-life of perimag-COOH, a commercially available SPION with a larger hydrodynamic size (130 nm) than ferucarbotran (65 nm). These findings indicate successful diversion of SPIONs away from the hepatic RES and show realistic potential for future clinical applications.

Fe3O4@MnO2@PPy nanocomposites overcome hypoxia: magnetic-targeting-assisted controlled chemotherapy and enhanced photodynamic/photothermal therapy.

Considering traditional treatment methods, such as chemotherapy, with their potential side effects and lack of targeting, photodynamic therapy (PDT) and photothermal therapy (PTT), being innovative, with less side effects, and light-controlled strategies for antitumour applications, have received extensive attention, but the efficacy of PDT is seriously hindered by the hypoxia tumour microenvironment. Here, a multifunctional nanocomposite composed of an iron oxide (Fe3O4) core and two shells of manganese dioxide (MnO2) and polypyrrole (PPy) was successfully prepared and used to solve these issues. PPy, simultaneously as the photothermal agent and photosensitizer, was first combined with MnO2 to coat magnetic Fe3O4 for achieving an increase in the intracellular O2 concentration and to improve the generation ability of singlet oxygen upon laser irradiation, so that enhanced PDT/PTT could be obtained. After the efficient loading of doxorubicin (DOX) on the Fe3O4@MnO2@PPy nanocomposite, an acid controlled-release behaviour for DOX as well as magnetic-targeting-assisted synergistic effects of chemotherapy and improved PDT/PTT for tumour cells could be realized, which could also protect normal cells from damage. All these features may render our nanocomposite a promising platform to reverse hypoxia-triggered PDT resistance and chemotherapy-caused side effects in cancer therapy and other biomedical applications.

Convection Dynamics of Fe3O4 Nanoparticles in Blood Fluid Flow

In this paper, the convection dynamics of super paramagnetic iron oxide nanoparticles (MNPs) in blood fluid is studied. The system under consideration consists of a fluid which contains the layer of blood with MNPs having iron oxide core (Fe3O4) nanoparticle which is moving through the cavity of the blood vessel which has depositions of cholesterol on the inner lining. In its passing through the blood vessel it is subjected to external magnetic field and heat. The nonlinear three dimensional governing equations for the system under study are derived from the partial differential equations of conservation of momentum and energy. The effect of magnetic field for Hartman number on the chaotic convection of the MNPs in blood fluid is studied using phase portrait, time series and stability analysis. It is assumed that a minimum magnetic field is necessary to stabilise the convection of the MNPs to regulate its flow in specific directions so that the drug can be delivered to specific locations by magnetic dragging. Rectangular cavity structure is considered for the study based on non-uniform cholesterol deposition. It is observed that with magnetisation by external applied magnetic field the convection of MNPs are stabilised in a particular direction. This indicates towards the growing utilization as contrast agents in non-invasive imaging technique of magnetic resonance imaging (MRI) and magnetic drug delivery (MDD).

Nanocomposites for luminescent tumour diagnostics and theranostics

This paper describes the synthesis method and the spectral-luminescent properties of nanoparticles containing the ytterbium complex of protoporphyrin IX dimethyl ether in Lexan-based polymer matrix which are promising for use in tumours diagnostics. For theranostics purposes, the synthesis of multifunctional nanoparticles containing iron oxide core and Lexan-polymer shell, including ytterbium porphyrin complexes (YPC), was carried out. The iron oxide nanoparticles are responsible for carrying out the local hyperthermia procedure when exposed to a high-frequency magnetic field.