Sharif Digital Repository

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... 

Gallium-67 labeled superparamagnetic iron oxide nanoparticles ([ 67Ga]-SPION were prepared and evaluated for their altered biodistribution in normal rats. Superparamagnetic iron oxide nanoparticles (SPION) with narrow size distribution were synthesized by a co-precipitation technique using ferrous salts at Fe3+/Fe2+ = 2 molar ratio followed by structure identification using XRD, TGA, DSC, VSM, HRSEM, TEM and FT-IR techniques (≈ 5 nm diameter). In order to trace SPION bio-distribution, the radiolabeled iron oxide nanoparticles were prepared using 67Ga with a high labeling efficiency (over 96%, RTLC method) and they also showed an excellent stability at room temperature for at least 4 d. The... 

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... 

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  

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 (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... 

Background: The aim of this study was to investigate the neurotoxic effects of Fe3O4 magnetic- CurNPs on isolated schizophrenia mitochondria of rats as an in vivo model. Methods: We designed CMN loaded superparamagnetic iron oxide nanoparticles (SPIONs) (Fe3O4 magnetic- CurNPs) to achieve an enhanced therapeutic effect. The physicochemical properties of Fe3O4 magnetic- CurNPs were characterized using X-ray diffraction (XRD), and dynamic laser light scattering (DLS) and zeta potential. Further, to prove Fe3O4 magnetic- CurNPs results in superior therapeutic effects, and also, the mitochondrial membrane potential collapse, mitochondrial complex II activity, reactive oxygen species generation,... 

Superparamagnetic iron oxide nanoparticles with proper surface coatings are increasingly being evaluated for clinical applications such as hyperthermia, drug delivery, magnetic resonance imaging, transfection, and cell/protein separation. To enhance the applicability of magnetic nanoparticles, two main problems must be overcome. First, as the drug coats the particle surface, a significant portion of it is quickly released upon injection (burst effect). Therefore, only small amounts of the drug reach the specific site after, for example, magnetic drug targeting. Second, once the surface-derivatized nanoparticles are inside the cells, the coating is likely digested, leaving the bare particles... 

Aggregation of the natively unfolded protein α-synuclein (α-syn) is key to the development of Parkinson's disease (PD). Some nanoparticles (NPs) can inhibit this process and in turn be used for treatment of PD. Using simulation strategies, we show here that α-syn self-assembly is electrostatically driven. Dimerization by head-to-head monomer contact is triggered by dipole-dipole interactions and subsequently stabilized by van der Waals interactions and hydrogen bonds. Therefore, we hypothesized that charged nano-objects could interfere with this process and thus prevent α-syn fibrillation. In our simulations, positively and negatively charged graphene sheets or superparamagnetic iron oxide... 

Background: Genistein (C15H10O5) is a soy isoflavone with anti-cancer properties such as inhibition of cell growth, proliferation and tumor invasion, but effective dosage against hematopoietic malignant cells was not in non-toxic range. This property cause to impede its usage as chemotherapeutic agent. Therefore, this hypothesis raised that synthesizing biocompatible nanoparticle could assist to prevail this struggle. Methods: Genistein covalently attached on Fe3O4 nanoparticles decorated with carboxymethylated chitosan to fabricate Fe3O4-CMC-genistein in alkaline circumstance. This obtained nanoparticles were evaluated by TEM, DLS, FTIR, XRD and VSM and its anti-cancer effect by growth rate... 

In the present study, bubble-driven magnesium-based micromotors were fabricated through a shading method, and the potential of magnetic guidance of magnesium-based Janus micro/nanomotors through functionalization with superparamagnetic iron oxide nanoparticles (SPIONs) was investigated for the first time. SPIONs had physical electrostatic attraction with the positively charged magnesium spheres due to negative charges on their surfaces. It was also found that upon applying a field gradient, the micromotors’ velocity increased by 13% unlike other magnetically navigated spherical magnesium-based micromotors which only show a change in direction. In this work the cytotoxicity of the moving... 

The performance of nanoparticles for biomedical applications is often assessed by their narrow size distribution, suitable magnetic saturation and low toxicity effects. In this work, superparamagnetic iron oxide nanoparticles (SPIONs) with different size, shape and saturation magnetization levels were synthesized via a co-precipitation technique using ferrous salts with a Fe3+/Fe2+ mole ratio equal to 2. A parametric study is conducted, based on a uniform design-of-experiments methodology and a critical polymer/iron mass ratio (r-ratio) for obtaining SPION with narrow size distribution, suitable magnetic saturation, and optimum biocompatibility is identified. Polyvinyl alcohol (PVA) has been... 

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... 

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... 

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...