Sharif Digital Repository

Superparamagnetic iron oxide nanoparticles (SPIONs) are increasingly used in medical applications, such as targeting delivery and imaging. In the future, patients are more likely to be exposed to pharmaceutical products containing such particles. The study of toxicity of SPIONs has become of great importance in recent years, although the published data in this arena is limited. The aim of the present work is to investigate the cytotoxicity of SPIONs and the effect of the particles on the cell medium components. For this purpose, uncoated and polyvinyl alcohol (PVA) coated SPIONs with narrow size distribution were synthesized via a well-known coprecipitation method. The mouse fibroblast cell... 

Gallium-67 labeled superparamagnetic iron oxide nanoparticles were prepared and evaluated for their altered biodistribution in normal rats. Superparamagnetic iron oxide nanoparticles with narrow size distribution were synthesized by co-precipitation technique using ferric and ferrous salts at molar ratio Fe3+/Fe2+=2:1 followed by structure identification using XRD, thermo gravimetric analysis , differential scanning calorimetric , vibrating sample magnetometer, high-resolution scanning electron microscopy,transmission electron microscopy and fourier transform infrared absorption techniques. In order to trace superparamagnetic iron oxide nanoparticles bio-distribution, the radiolabeled iron... 

A novel magnetic nanocarrier with long spacer length and high colloidal stability has been prepared for effective delivery of doxorubicin (DOX). First, poly(amidoamine) (PAMAM) dendrimer was grown up onto the surface of superparamagnetic iron oxide nanoparticles to increase the loading amount of amine groups. Then, terminal amine groups were functionalized by polyethylene glycol dimethylester to increase the spacer length. Then anticancer drug DOX was covalently attached onto the system by hydrazone bond to forms a pH-sensitive nanocarrier. This system is designed to combine the advantage of magnetic targeting, high drug loading capacity, and controlled release  

A novel Fe3O4-poly(aniline-naphthylamine)-based nanocomposite was synthesized by chemical oxidative polymerization process as a magnetic sorbent for micro solid phase extraction. The scanning electron microscopy images of the synthesized nanocomposite revealed that the copolymer posses a porous structure with diameters less than 50nm. The extraction efficiency of this sorbent was examined by isolation of rhodamine B, a mutagenic and carcinogenic dye, from aquatic media in dispersion mode. Among different synthesized polymers, Fe3O4/poly(aniline-naphthylamine) nanocomposite showed a prominent efficiency. Parameters including the desorption solvent, amount of sorbent, desorption time, sample... 

Supported iron oxide nanoparticles are found to be efficient and recoverable catalyst in the selective oxidation of thiols to their corresponding disulfides using hydrogen peroxide as green oxidant at room temperature. The protocol features an easy work-up, simplicity and the utilizing mild reaction conditions, as well as high selectivity toward disulfides, are highly advantageous compared to alternative reported methodologies. The supported iron oxide nanoparticles could be easily recovered and reused several times without any loss of activity. ICP-MS results prove that there is no metal leaching observed, and demonstrating the stability of the catalyst under the reaction conditions  

Superparamagnetic Iron Oxide Nanoparticles (SPIONs) were synthesized and coated with pseudopolyrotaxanes (PPRs) and proposed as a novel hybrid nanostructure for medical imaging and drug delivery. PPRs were prepared by addition of α-cyclodextrin rings to functionalized polyethylene glycol (PEG) chain with hydrophobic triazine end-groups. Non-covalent interactions between SPIONs and PPRs led to the assembly of SPIONs@PRs hybrid nanomaterials. Measurements of the 1H Nuclear Magnetic Resonance (NMR) relaxation times T1 and T2 allowed us to determine the NMR dispersion profiles. Comparison between our SPIONs@PRs hybrid nano-compound and the commercial SPION compound, Endorem®, showed a higher... 

Azlactones have been prepared via Erlenmeyer synthesis from aromatic aldehydes and hippuric acid using Fe 2O 3 nanoparticles under ultrasonic irradiation. Short reaction times, easy and quick isolation of the products, and excellent yields are the main advantages of this procedure  

To efficiently enhance the contrast obtaining from magnetic resonance imaging (MRI), pharmaceutical grade colloidal dispersions of PEG coated iron-based nanoparticles were prepared and compared to conventional pure iron oxide contrast agent. In this study, we synthesized ∼14 nm iron nanoparticles via NaBH4 reduction of iron(III) chloride in an aqueous medium. The resulting nanoparticles were further oxidized by two different methods via (CH3)3NO oxygen transferring agent and exposure to oxygen flow. XRD and electron microscopy analyses confirmed the formation of a second layer on the surface of α-Fe core. As magnetic measurements and Mössbauer spectra of 4-months post prepared nanoparticles... 

Due to the hopeful potential of nanoparticles in medicine, they have attracted much attention for various applications such as targeted drug/gene delivery, separation or imaging. Interaction of NPs with the biological environment can lead to a wide range of cellular responses. In order to have safe NPs for biomedical applications, the current biocompatibility researches are particularly focused on the severe toxic mechanisms which cause cells death. These mechanisms are apoptosis, autophagy and necrosis, which can also be intricately linked with the cell-life cycle, as there are various check-points and controls in a cell's life cycle to ensure appropriate division processes. Mechanisms by... 

Superparamganetic iron oxide-based contrast agents in magnetic resonance imaging (MRI) have offered new possibility for early detection of lymph nodes and their metastases. According to important role of nanoparticle size in biodistribution, magnetite nanoparticles coated with different polyethylene glycol (PEG) concentrations up to 10/1 PEG/iron oxide weight ratio in an ex situ manner. To predict the PEG-coated nanoparticle behavior in biological media, such as blood stream or tissue, colloidal stability evaluation was performed to estimate the coating endurance in different conditions. Accordingly, optical absorbance measurements were conducted in solutions with different values of pH and... 

Iron oxide nanoparticles supported on mesoporous silica-type materials have been successfully utilized in the aqueous selective oxidation of alkenes under mild conditions using hydrogen peroxide as green oxidant. The supported catalyst could be easily recovered after completion of the reaction and reused several times without any loss in activity (no metal leaching observed during the reaction), constituting a facile and straightforward example of aqueous oxidation chemistry promoted by iron-based heterogeneous systems. Copyright  

Context: Elevated expression of the folate receptor (FR) occurs in many human malignancies. Thus, folate targeting is widely utilized in drug delivery purposes specially using nano-radioactive agents. Aims: In this work, we report production and biological evaluation of gallium-67 labeled superparamagnetic iron oxide nanoparticles, embedded by folic acid (67 Ga-SPION-folate) complex especially in tumor-bearing mice for tumor imaging studies. Settings and Design: The structure of SPION-folate was confirmed by X-ray diffraction (XRD), transmission electron microscopy (TEM) and foureir transform infrared spectroscopy (FT-IR) analyses. The radiolabeled SPION-folate formation was confirmed by... 

Superparamagnetic iron oxide nanoparticles were synthesized by coprecipitation of iron chloride salts at various pH values (9, 10, 11 and12) that were adjusted using an ammonia solution. Increasing the pH from 9 to 12 led to decreases in the size of iron oxide nanoparticles from 7.9±1.4 to 5±0.6 nm and the saturation magnetization (M s) from 82.73 to 67.14 emu/g, respectively, when analyzed with transmission electron microscopy (TEM) and vibrating sample magnetometer (VSM). X-ray diffraction patterns as well as M s values showed that magnetite is the dominantly synthesized phase in the examined pH values. Unmodified iron oxide nanoparticles were coated with silica via the hydrolysis and... 

Iron oxide nanoparticles, γ-Fe2O3NP, were deposited onto the surface of multi-walled carbon nanotubes and CNT/γ-Fe2O3NP hybrid nanomaterials were obtained. Then linear-dendritic ABA type block copolymers consisting of polyethylene glycol as B block and poly(citric acid) as A block, PCA-PEG-PCA, were synthesized and cisplatin (cis-diamminedichloroplatinum (CDDP) - a platinum-based chemotherapy drug) was conjugated with their carboxyl functional groups and CDDP/PCA-PEG-PCA anticancer prodrugs were prepared. Noncovalent interactions between CDDP/PCA-PEG-PCA anticancer prodrugs and CNT/γ-Fe2O3NP hybrid nanomaterials led to CDDP/PCA-PEG-PCA/CNT/γ-Fe2O3NP drug delivery systems. There are several... 

Fetal stem cells, which can be isolated from the organs of fetuses, differentiate along multiple lineages. Their advantages over their adult counterparts include better intrinsic homing and engraftment and lower immunogenicity, and they are less ethically contentious. It is noteworthy that Mesenchymal Stem Cells (MSC) can be activated and mobilized at the site of damaged tissue. Since vascular delivery suffers from a pulmonary first pass effect, direct or systemic injection of MSCs into the damaged tissue is preferred, particularly in the case of versatile tissue ischemia. Ultrasound applies acoustic energy with a frequency above human hearing (20 kHz). Ultrasound imaging or sonography... 

In this study, superparamagnetic iron oxide nanoparticles (SPION) embedded by folic acid (SPION-folate) were prepared by a modified co-precipitation method. The structure, size, morphology, magnetic property and relaxivity of the SPION-folate were characterized systematically by means of XRD, VSM, HRSEM and TEM and the interaction between folate and iron oxide (Fe3O 4) was characterized by FT-IR. The particle size was shown to be ≈5-10 nm. To ensure biocompatibility, the interaction of these SPION with mouse connective tissue cells (adhesive) was investigated using an MTT assay. Consequently, gallium-67 labeled nanoparticles ([67Ga]-SPION-folate) were prepared using 67Ga with a high labeling... 

At present, nanoparticles are used for various biomedical applications where they facilitate laboratory diagnostics and therapeutics. More specifically for drug delivery purposes, the use of nanoparticles is attracting increasing attention due to their unique capabilities and their negligible side effects not only in cancer therapy but also in the treatment of other ailments. Among all types of nanoparticles, biocompatible superparamagnetic iron oxide nanoparticles (SPIONs) with proper surface architecture and conjugated targeting ligands/proteins have attracted a great deal of attention for drug delivery applications. This review covers recent advances in the development of SPIONs together... 

In the present research, iron oxide nanoparticles were synthesized through the hydrothermal method, and the influence of processing parameters such as pH of the initial coprecipitation reaction, time and temperature of hydrothermal treatment was studied. The magnetic iron oxide nanoparticles were coated with a negatively charged, thin layer of silica. The product is then coated with a layer of mesoporous silica. As a result of the electrostatic attraction between the cationic CTAB and the primary silica coating, the formation of mesoporous silica would be mainly localized on the surface of nanoparticles. Calcination was performed in an argon atmosphere tube furnace at 550 °C, through which... 

Four derivatives of hyaluronic acid (HA) bearing thiol (HA-SH), hydrazide (HA-hy), 2-dithiopyridyl (HA-SSPy), and aldehyde groups (HA-al) respectively were synthesized. Thiol and 2-dithiopyridyl as well as hydrazide and aldehyde make up two chemically orthogonal pairs of chemo-selective functionalities that allow in situ formation of interpenetrating (IPN) disulfide and hydrazone networks simultaneously upon the mixing of the above derivatives at once. The formation of IPN was demonstrated by comparing it with the formulations of the same total HA concentration but lacking one of the reactive components. The hydrogel composed of all four components was characterized by a larger elastic...