More than 22% of the world's agricultural land is saline, and this trend continues to increase with climate changes. Salinity stress causes leaf color change, osmotic stress, ionic toxicity, prevents growth, photosynthesis and plant performance. Due to their size less than micron, metal nanoparticles have a great absorption and transmission power in plants. Salinity stress is a major problem in hot and dry areas under tomato cultivation. For this purpose, investigating the mutual effects of the size and type of zinc oxide and iron oxide nanoparticles on the improvement and change of growth and increasing the resistance to salt stress in tomato plants of the early urbana variety were carried out in the form of a completely randomized and factorial design with 4 replications, at a significant level of 5%. In this research, zinc oxide nanoparticles in 25 and 50 nm sizes, iron oxide in 25 nm sizes and sodium chloride in 0 and 75 mM levels were used. nanoparticles and salinity treatments were both applied to the plants. The results showed that salt stress led to a decrease in plant growth parameters such as shoot and root length, leaf area, RWC, ion leakage. Also, NaCl led to an increase in the accumulation of prolin and other aldehydes, sodium, iron and zinc. The application of nanoparticles had a slight effect in stress-free conditions, but in stressed conditions, these two nanoparticles alone and especially in combination neutralized the effect of salinity and reduced the damage caused by salinity stress.

The present study is devoted to the development of a new magnetic resonance contrast agent based on superparamagnetic magnetite nanoparticles. The aim of the study is to create a contrast agent with improved characteristics compared to existing analogues. The process of obtaining includes two main stages such as the formation of the embryo and the growth of particles by aggregation. The size of the nanoparticles was controlled to achieve superparamagnetism. The concentration of iron in the solution was determined by X-ray fluorescence analysis. The phase composition was confirmed by X-ray phase analysis. Transmission electron microscopy and proton relaxometry were employed to evaluate the obtained solutions. The study showed that the optimal concentration of superparamagnetic nanoparticles in an aqueous solution is 0.5 mg/mL. The relaxation abilities of the synthesized particles were determined: for superparamagnetic particles (5-8 nm) - t ≈: 12.1 l/(mmol·s), t ≈: 30.1 l/(mmol·s); for ferrimagnetic particles (30-50 nm) - t ≈: 3.2 l/(mmol·s), t ≈: 35 l/(mmol·s). The cytotoxicity of the obtained nanoparticles was evaluated using an MTT test on fibroblast cells. It was found that at concentrations lower than 0.5 mg/mL, the particles do not exhibit a toxic effect on normal fibroblast cells. The research results demonstrate the feasibility of creating a new contrast agent for MR tomography based on synthesized nanoparticles of complex iron oxide. The developed contrast agent outperforms existing analogues in its characteristics and shows promising results in terms of biocompatibility.

Introduction: iron oxide nanoparticles, owing to their very small size and superparamagnetic properties, have been considered a potential candidate for several medical applications such as magnetic cell separation, magnetic resonance imaging (MRI), magnetic targeted drug delivery magnetic hyperthermia. The present study aimed to synthesize and evaluate the characteristics of superparamagnetic iron oxide nanoparticles (SPIONs) and determine the mechanism by which they induce cell death in the presence of an extremely low-frequency magnetic field (ELMF).Methods: First, SPIONs were synthesized using the chemical co-precipitation method and then characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), dynamic light scattering (DLS), and zeta potential. A vibrating-sample magnetometer (VSM) was used to measure the magnetic properties of the nanoparticles. Human MCF-7 breast cancer cells were treated with different concentrations of SPION in the absence and presence of a 50-Hz ELMF for 24 and 48 h. Cytotoxicity and cell viability percentage in the treated cells were measured by the MTT (3-(4, 5-dimethylthiazol- 2-yl)-2, 5-diphenyltetrazolium bromide) assay. Results: DLS and TEM analyses indicated that the SPIONs have an average size of less than 30 nm and they are superparamagnetic. VSM analyses also confirmed the superparamagnetic nature of the nanoparticles. The MTT assay indicated that high concentrations of SPIONs induced death in MCF-7 cells. In the groups treated with ELMF+SPIONs, cell death increased sharply compared with that in the groups treated with each treatment alone (P≤0.05).Conclusions: It seems that a 50-Hz ELMF in the presence of SPIONs led to cell death due to local heating.

In this paper, polymer grafted nickel-doped iron oxide nanoparticles are fabricated via an easy, one-step and fast electrochemical procedure. In the deposition experiments, iron(II) chloride hexahydrate, iron(III) nitrate nonahydrate, nickel chloride hexahydrate, and dextran were used as the bath composition. Dextran grafted nickel-doped iron oxides (DEX/NiSPIOs) were synthesized with applying direct current (dc) of 10 mA cm – 2. The magnetite crystal phase, nano-size, Ni doped content, and dextran grafting onto SPIOs were verified through X-ray powder diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, field-emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM) and thermogravimetric (TG) and differential scanning calorimetry (DSC) analyses. Magnetic evaluation through vibrating-sample magnetometer (VSM) proved that the DEX/Ni-SPIOs product have superparamagnetic behavior with exhibiting the high saturation magnetization and negligible Ms and Hci values. Based on the obtained results, it was confirmed that the prepared dextran grafted Ni-SPIOs have suitable physico-chemical and magnetic properties for both therapeutic and diagnostic aims.

Objective: superparamagnetic iron oxide nanoparticles (SPIONs) have been used to label mammalian cells and to monitor their fate in vivo using magnetic resonance imaging (MRI). However, the effectiveness of phenotype of labeled cells by SPIONs is still a matter of question. The aim of this study was to investigate the efficiency and biological effects of labeled mouse embryonic stem cells (mESCs) using ferumoxide- protamine sulfate complex.Materials and Methods: In an experimental study, undifferentiated mESCs, C571 line, a generous gift of Stem Cell Technology Company, were cultured on gelatin-coated flasks. The proliferation and viability of SPION-labeled cells were compared with control. ESCs and embryoid bodies (EBs) derived from differentiated hematopoietic stem cells (HSCs) were analyzed for stage-specific cell surface markers using fluorescence-activated cell sorting (FACS).Results: Our observations showed that SPIONs have no effect on the self-renewal ability of mESCs. Reverse microscopic observations and prussian blue staining revealed 100% of cells were labeled with iron particles. SPION-labeled mESCs did not significantly alter cell viability and proliferation activity. Furthermore, labeling did not alter expression of representative surface phenotypic markers such as stage-specific embryonic antigen 1 (SSEA1) and cluster of differentiation 117 (CD117) on undifferentiated ESC and CD34, CD38 on HSCs, as measured by flowcytometry.Conclusion: According to the results of the present study, SPIONs-labeling method as MRI agents in mESCs has no negative effects on growth, morphology, viability, proliferation and differentiation that can be monitored in vivo, noninvasively. Non-invasive cell tracking methods are considered as new perspectives in cell therapy for clinical use and as an easy method for evaluating the placement of stem cells after transplantation.

The application of iron (III) oxide nanoparticles in biology and medicine is much more than the other magnetic nanoparticles. Biocompatibility with human body, stability and ease of production caused the wide range of its development. Single-phase iron (III) oxide nanoparticles were synthesis by use of factory waste soil instead of feedstock with low temperature wet chemical cleaving oxygen method. With respect to the precursor material that is factory waste soil (feedstock), it is cost-effective economically and also is innovative. In this synthesis method, single-phase iron(III) oxide were obtained by acid digestion of waste soil. The nanoparticles were analyzed by: Fourier Transform Infrared spectroscopy (FTIR), X-Ray Diffraction (XRD) that the crystallite size of nanoparticles calculated by XRD peaks and Debye-Scherrer formula and obtained 11 nm. Transmission Electron Microscope (TEM) images showed the spherical shape of nanoparticles with average size of 10 nm. Vibrating sample magnetometery (VSM) analysis was applied to determine the magnetic saturation and the size of nanoparticles was estimated 9 nm from this analysis. Fourier Transform Infrared spectroscopy gently shows the atomic bond between iron and oxygen (Fe-O) in nanoparticles. The results of X-ray Diffraction show that the sample was synthesized are cubic Spinel single-phase.

Introduction: Hyperthermia is rapidly becoming a clinical reality as a tool for the treatment of malignant disease but there are some major problems in the way of using superparamagnetic nanoparticles coated with polymer in medical applications. Modifying the magnetic nanoparticles without using surface coating is more appropriate. In this study, we presented a new physical technique, by surface treatment of nanoparticles with argon gas plasma, to modify the surface of nanoparticles for improving their crystal structure and magnetization. Materials and Methods: In this study, Fe3O4 nanoparticles were synthesized using the co-precipitation method. The nanoparticles were then treated with plasma in a vacuum chamber. In this method, the Radio Frequency (RF) generator 13. 56 MHz was used as a power supply and the plasma treatment was applied for 10 and 15 min. Results: Due to the decrease in surface irregularities, the nanoparticle aggregation decreased and their colloidal stability increased. Moreover, with Value Stream Mapping (VSM) analysis the magnetism of the nanoparticles improved along with an increase of plasma power a nd plasma treatment time due to the reduced crystal defects and crystal growth. By using the AC magnetic field generator with a frequency of 92 kHz and amplitude of 125 Oe, results show that along with an increase of plasma power and plasma treatment time due to the increased magnetization and colloidal stability, heat generation by these nanoparticles increased in a ferrofluids system in the presence of AC magnetic field. In addition, the locking temperature of nanoparticles has also increased. Conclusions: Our results suggest that the surface modification of Fe3O4 nanoparticles, using plasma treatment, is an appropriate candidate for some medical applications such as magnetic resonance imaging, drug delivery, and especially for magnetic hyperthermia.

superparamagnetic iron oxide nanoparticles (SPIONs) are promising materials for various biomedical applications including targeted drug delivery and imaging, hyperthermia, magneto-transfections, gene therapy, stem cell tracking, molecular/cellular tracking, magnetic separation technologies (e.g. rapid DNA sequencing), and detection of liver and lymph node metastases. The most recent applications for SPIONs for early detection of inflammatory, cancer, diabetes and atherosclerosis have also increased their popularity in academia. In order to increase the efficacy of SPIONs in the desired applications, especial surface coating/characteristics are required. The aim of this article is to review the surface properties of magnetic nanoparticles upon synthesis and the surface engineering by different coatings. The biological aspects, cytotoxicity, and health risks are addressed. Special emphasis is given to organic and inorganic-based coatings due to their determinant role in biocompatibility or toxicity of the final particles.