Sharif Digital Repository

In recent years, many efforts have been made in the field of drug delivery with hydrogel nanoparticles. This class of materials has been at the center of attention in medical science due to their improved physical and biological properties including high amount of water preservation, penetration, bio capampatibility and physical structure similar to outside matrices of tissue. Among various applications in medical sciences, drug delivery based on hydrogels is very attractive. Hydrogels can protect drugs from aggressive environmental factors such as pH and thermal changes, and presence of enzymes. The porosity of hydrogels facilitates drug loading into the gel matrix and provides a... 

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... 

The aim of this study was to investigate the rate of increase in temperature of a phantom equivalent to body tissue by different groups of magnetic iron nanoparticles in the external magnetic field to kill cancer cells based on the hyperthermia method. To achieve this goal, three groups of dextran magnetic nanoparticles with different properties and reduced iron oxide-graphene oxide magnetic nanoparticles by M-rGO supercritical synthesis method were used. After XRD, FTIR, SEM, FESEM, VSM, TEM characterization tests, these materials were placed in a phantom made of agarose gel and with the same properties, in a magnetic field with fixed characteristics for all groups and during the process of... 

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... 

Cancer is one of the most important problems that affects public health. If this disease is diagnosed quickly in the patient's body, it can be prevented and treated by determining the stage of the disease and establishing a treatment protocol. Magnetic resonance imaging (MRI) and fluorescence imaging (FI) are among the imaging methods. In order to increase the contrast of images, researchers have turned to the synthesis of materials under contrast agents, which improve diagnostic sensitivity. Synthesis of nanoparticles as multi-mode contrast agents can enhance imaging methods. In this research, the synthesis and characterization of the multifunctional Fe3O4-Mn3O4-LCysteine@g-C3N4 QDs system... 

The use of magnetic nanoparticles modified with proper surface agent and the ability of controlling by magnetic field, that can induce colloidal stability, is considered as a vector to transfer DNA plasmid, or pDNA in short, in the field of gene therapy. In thiss research, pH-responsive dextran-based magnetic nanogels (dextMNGs) were synthesized via inverse mini-emulsion method. Fourier transformation infrared spectroscopy (FTIR) showed that magnetite nanoparticles (MNPs) were successfully modified with arginine and had amine terminals. FTIR, also, proved that aldehyded dextran was crosslinked by arginine modified magnetite nanoparticles (RMNPs) via pH sensitive imine bonds. X-ray... 

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... 

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... 

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... 

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... 

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... 

The aim of this research is to study the effect of surfactant type and the concentration reactants on the size, shape and magnetic properties of iron-gold core-shell magnetic nanoparticles (NPs) useable for biomedical application. The reverse micelle procedure was employed to synthesize iron NPs using two surfactants of CTAB and SDS. A gold shell with a thickness in the range of 10 to 40 nm was induced by reverse micelle method in order to prevent oxidation of the iron core. The size and morphology of NPs were studied by transition electron microscopy (TEM). It was found that the size of NPs increases by the increasing the reactants concentration while the morphology of the NPs was not... 

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...