Sharif Digital Repository

Superparamagnetic iron oxide nanoparticles (SPION) with proper surface coatings are increasingly being evaluated for clinical applications such as hyperthermia, drug delivery, magnetic resonance imaging, transfection, and cell/protein separation. Since the particles with various sizes exhibit different flow rates in the same environment (same capillary size), it is essential to use particles of a desirable size for targeted drug delivery and imaging. Particles of different sizes may be exposed to different viscosities and behave differently, particularly with regard to their velocities as they move through capillaries. In the present work, SPION with different size, purity, shape and... 

In this study new magnetic solid phase extraction (MSPE) methods based on Fe3O4 magnetic nanoparticles (NPs) for extraction and preconcentration of oxadiargyl and fuoxetine from aqueous and biological samples were developed. In the first work, Fe3O4 NPs was successfully used as a magnetic nano-sorbent in magnetic micro-solid phase extraction (M-µ-SPE) of oxadiargyl, a newly used pesticide, from environmental water samples prior to gas chromatography-mass spectrometry determination. Oxadiargyl in mild acidic condition has tendency to be adsorbed on Fe3O4 NPs surfaces. Most important parameters that affect the extraction efficiency were also studied. Under optimized condition, the proposed... 

In this research, the effect of feed flow concentration on the separation of gas mixture of carbon dioxide and oxygen was investigated by using supported liquid membrane in the presence of nano particles. In order to achieve this purpose, supported liquid membranes were prepared by impregnating a porous hydrophilic PVDF support with TEG, cyclohexanol, TEG/Fe3O4 nano particles and cyclohexanol/ Fe3O4 nano particles. Permeability and selectivity of mixed gases CO2 and O2 were examined at five different CO2 concentrations in feed flow, constant feed flow rate and constant total pressure difference.
In all tests, the permeance of carbon dioxide through cyclohexanol and TEG membranes was... 

Age-related macular degeneration (AMD) is the most common cause of vision loss in those aged over 50. There are two main types of AMD, Wet and Dry form. Wet AMD is more severe though more treatable. There are three conventional treatments for AMD including laser therapy, surgery and intravitreal injection of anti-VEGF into the eye. Delivery of drugs to the posterior segment of the eye is still challenging and several implants and devices are currently under investigation for their ability to stimulate the retina, producing visual percepts. The application of intravitreal bevacizumab (Avastin) has expanded tremendously from the time of its introduction into ophthalmic care since 3 years ago.... 

Age-related macular degeneration (AMD) is the most common cause of vision loss in those aged over 50. There are two main types of AMD, Wet and Dry form. Wet AMD is more severe though more treatable. There are three conventional treatments for AMD including laser therapy, surgery and intravitreal injection of anti-VEGF into the eye. Delivery of drugs to the posterior segment of the eye is still challenging and several implants and devices are currently under investigation for their ability to stimulate the retina, producing visual percepts. The application of intravitreal bevacizumab (Avastin) has expanded tremendously from the time of its introduction into ophthalmic care since 3 years ago.... 

The aim of this project is the surface modification of super para magnetic iron oxide (SPIONs), leading to oriented covalent bonding of antibody(AB) to these nanoparticles (NPs) and improve the efficiency of cell separation at MACS columns. For this purpose, SPIONs synthesized by co-precipitation method, and the stability of colloidal NPs then was provided by coating with Dextran . We used TGA to measure weight percentage of dextran. Some properties like particle size, hydrodynamic diameter, presence of coating and superparamagnetic properties were characterized by XRD (16 nm), FTIR, DLS (73 nm), TEM (20nm) and VSM (≈76/78 emu/g) method, respectively. Then we tried to immobilize AB on NPs... 

In this thesis, heterogenous catalysts based on magnetic nanoparticles were synthesized. In these catalysts, magnetic nanoparticles were coated with defferent fuctional groups to produce a catalyst with magnetic properties which is easily separated from the reaction medium. The structure of synthesized catalyst was characterized using techniques such as transmission electron microscopy (TEM), scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FTIR), and CHNS elemental analysis. Easy preparation, low cost, biodegradability and high thermal stability are advantages of these catalysts. At the end, the catalytic properties of resulted catalysts were investigated in many... 

With development of nanotechnology in medicine, nanoparticles are used for detection of tumor and cancer biomarkers. Magnetic nanoparticles are widely used for therapeutic and diagnostic objectives, because of their biocompatibility, ease of preparation and strong magnetic properties. Genistein (C15H10O5) is a soy isoflavone which is used for its anti-cancer activities. It is used for inhibition of cell proliferation, cell growth, and tumor invasion. The aim of this study is to assess the impact of nano-conjugation of geinstein as chemotherapeutic agent against cancer. For preparation of typical iron oxide Nanoparticles, Magnetite nanoparticles were synthesized by coprecipitating iron (II)... 

The progress and the development of various industries, pollutants derived from the agricultural and industrial processes contaminate the environment. The degradation of these pollutants have an important effect on the environment.Magnetite (Fe3O4) nanoparticles and magnetite supported on functionalized activated carbon were synthesized and characterized by different techniques such as SEM, FT-IR, XRD, BET and VSM. The catalyst activity of these nanocatalysts was evaluated by the degradation of reactive red ME4BL (RRME4BL) textile dye in heterogeneous Fenton and electro-Fenton processes as a model pollutant. The effect of several parameters such as H2O2, RRME4BL concentration, the amount of... 

Superparamagnetic Iron Oxide NPs (SPIONs) because of their multi-task capabilities (e.g. magnetic labeling, cell isolation, hyperthermiaand controlled drug release) have been recognized as one of the most promising NPs for theranosis applications.When NPs come in contact with a biological medium, the surfaces of them are covered by biomolecules (e.g., proteins, natural organic materials, and enzymes). Therefore, what a biological entity, such as cells, tissues, and organs, sees when interacting with NPs is different original pristine surface of the NPs and actually is hard protein corona. Shape of NPs has a great impact on proteins adsorb onto its surface and consequently on the way that... 

As contrast enhancement agent, two different structures of superparamagnetic nanoparticles were synthesized. Iron oxide nanoparticles were prepared through an alkaline coprecipitation method of Iron (II) and (III) ions. PEG-6000 was used as biocapping material and its effect on particle size, colloidal stability and cytotoxicity was evaluated. On the other hand, novel core/shell structures were produced by NaBH4 reduction process of iron (III) in an aqueous media following by further oxidation by two different methods using (CH3)3NO oxygen transferring agent and exposure to oxygen flow. In both cases, structural examinations were conducted via X-ray diffraction, electron microscopy and... 

In the current research, colloidal stability of two different types of coating on the surface of Superparamagnetic Iron Oxide nanoparticles (SPIONs) was studied. In the first triumph, a dual-layer coating was achieved by utilizing optimum amount of Dextran and different PEG (Poly(ethylene glycol)) concentrations which the weight ratios of iron oxide/PEG were 1/1, 2/1, 4/1, 8/1, and 16/1. Then, the presence of the coating was characterized by XRD, FT-IR, DLS and FE-SEM methods. These results together with the TGA ones revealed that as the concentration of PEG surfactant increases, the thickness of coating increases. Moreover, VSM test was performed to specify the effect of coating on the... 

Recent drug delivery strategies have attempted to maximize the concentration of chemotherapeutic molecules into the tumors, while minimizing their systemic distribution. Doxorubicin has been widely used for a variety of cancers, successfully producing regression in acute leukaemia, lymphomas, soft-tissue and osteogenic sarcomas, paediatric malignancies and adult solid tumours, in particular breast and lung carcinomas. Common adverse effects of doxorubicin include hair loss, myelosuppression, nausea and vomiting, oral mucositis, oesophagitis, diarrhoea, skin reactions and serious reactions include hypersensitivity reactions, radiation recall, heart damage and liver dysfunction. Chitosan has... 

This thesis is divided into three parts: In part I, structure and electronic properties of ionic liquids based on N7, N9-dimethylguaninium cation and α-amino acid (Gly, His, Phe, Try, and Tyr) anions and also ionic liquids based on 1-ethyl-3-methylimidazolium [emim]+ cation and alkyl-trifluoroborate ([RBF3]-, R=n-CmH2m+1 (m=1-5)) anions were discussed at the DFT(B3LYP)/6-311++G(d,p) level of theory. Then, the effect of chain length in anion on the nature and strength of interaction between cation and anion was investigated. Our results indicated that interaction energy values decrease with the increase in side chain size in anion. NBO and QTAIM results indicated that the interaction in these... 

The main methods have been used clinically for cancer treatment are included: surgery, chemotherapy, radiation therapy and hyperthermia. Hyperthermia (heat therapy) treatment method in which by raising the temperature of the tumor it removed. Magnetic hyperthermia is known as a kind of hyperthermia that have been represent appropriate results. In this study, using iron oxide nanoparticle coated with graphene for cancer treatment under a magnetic field of the laser. In the first stage, graphene oxide nanosheets and nanoparticles Magntayt are synthesized by chemical oxidation and co-precipitation, respectively. At the end, the nanoparticles on the substrate of graphene layer is obtained... 

During the most recent years, investigating novel nanomaterials based on porous strucures has become an interesting field of research. Among these kinds of materials, mesoporous silica has extensive applications in catalysis, absorbants and biomedical engineering. By combining specific surface characteristics of mesoporous silica with magnetic properties of iron oxide nanoparticles, new nanocomposites owing unique properties, can be obtained. In the present research, magnetic mesoporous nanocomposite has been synthesized. Iron oxide nanoparticles were produced through reduction of water solution containing Fe2+/Fe3+ ions, followed by hydrothermal treatment of precipitan. Then, iron oxide... 

Cancer treatment is one of the most challenging issues of recent years. Extensive researches have been conducted in various fields of medicine, pharmacy, and medical physics in this regard. Today, considering nanotechnology developments, researchers believe that full cancer treatment is possible through the use of nano-systems designed with scientific background to overcome the defects of previous methods. In this research, the main purpose is to design and synthesize multifunctional hybrid nanostructures with favorable optical and magnetic properties providing a way to combine chemotherapy and thermal treatment. Accordingly, two different structures were designed and experimentally... 

Iron oxide nanoparticles were synthesized using microemulsion technique as MRI contrast agents. Utilization of nanoparticles for biological applications and in this case as MRI contrast agents needs particles to be of small size and also narrow size distribution. For this aim, the effect of several parameters on size and size distribution has been studied. These parameters include water/surfactant ratio, precursor’s concentration and amount of polymer employed to improve nanoparticles colloidal stability. XRD, FE-SEM and TEM results reveal that the synthesized nanoparticles had small size (about 10 nm iron oxide core and 20 nm overall diameter) and possessed narrow size distribution (15-21... 

A novel Fe3O4/poly (aniline-naphthylamine) (ANI-NA)-based nanocomposite was synthesized by chemical oxidative polymerization process as a magnetic sorbent for magnetic solid phase extraction. The extraction efficiency of this sorbent was examined by isolation of rhodamine B (RhB), a mutagenic and carcinogenic dye from aquatic media in dispersion mode. The efficiency of the synthesized Fe3O4/copolymer composite was examined and compared with Fe3O4/polyaniline (PANI) and Fe3O4/polynaphthylamine (PNA) by quantification of RhB using spectrofluorimetry. Among them, Fe3O4/poly (ANI-NA) nanocomposite showed a prominent efficiency. The scaning electron microscopy (SEM) image of the synthesized... 

The use of magnetic compounds for drug delivery and magnetic imaging has been studied in many studies. The easy use of magnetic particles makes them widespread. By applying a magnetic field, the particles reach the desired position and return to the original state by cutting off the field. The use of these magnetic materials in the nanoscale also adds other benefits, including: convenient and rapid transfer of nanoparticles, rapid repulsion of the kidneys, reducing the risk of overdose, etc. In recent years, the use of quantum dots for the diagnosis and treatment of tumors has attracted much attention. The use of hybrid quantum dots and magnetic nanoparticles can incorporate the desired...