Sharif Digital Repository

Application of nanoparticles in targeted delivery and controlled drug release is recently highly attracted especially in cancer therapy. In this study with the aim of developing a novel drug vector based on metallic nanoparticles, gold nanoparticles with their unique characteristics were used to design a vector for targeted anti-cancer drug delivery to tumor. First, gold nanoparticles were chemically synthesized therough sodium citrate and sodium brohydrate reductions with average diameters of 22 and 11 nm, respectively. Then, the activated poly ethylene glycol (PEG) and activated folic acid were conjugated to the lysine-capped gold nanoparticles. Subsequently, the widely used anticancer... 

Plasticizers in cementitious systems are additives that upon addition at a low dosage can change the workability, mechanical strength and other properties of cement paste effectively. In this study, tri-block copolymers based on poly ethylene glycol (PEG) was synthesised and their applications in the cementitious systems investigated. The main purpose is the verification of plasticizing effects of these copolymers in the cement paste. ABA tri-block copolymers with PEG (1000 and 1500 g/mol) as B block, poly caprolactone, poly caprolactam, poly lactide and poly glycolide (with different weight ratio) as A block were synthesised via ring opening polymerization with stannous octanoate as... 

In this study, a novel electrospun modified polyamide (PA) based nanofibers were synthesized and employed as fibers coating for rapid determination of chlorophenols. The major polymer solution contained PA along with polyethylene glycol (PEG), acting as a side low molecular weight polymer. After production of the PA−PEG fiber coating, PEG was subsequently removed and modified by water which was confirmed by Fourier transform infra-red spectrometry.The scanning electron microscopy images showed anaverage diameter of 640 and 148 nmforPA and PA−PEG coatings, respectively while the latter coating structure was homogeneous and porous.The extraction efficiency of unmodified and modified coatings... 

Today, tissue engineering research is expanding to a large extent, so tissue engineering has the ability to build artificial organs and tissues. In this project, we have used two polymers of polyethylene glycol and polyvinyl chloride, which are used for network irradiation. After irradiation, these polymers were made by drying the freewheeling porous scaffolds and the effect of different parameters on the structure of these scaffolds was investigated. To investigate the effect of different factors on gelation, swelling, tensile test, degradability and finally the conditions of fibroplast cell growth on scaffolds were investigated. The results of the gel test showed that the gel was higher... 

In this study, a series of polyoxometalates nanoclusters is synthesized and their catalytic properties have been investigated in oxidation and coupling reactions. In the first and second sections, {Mo36} nanoclusters are primarily prepared. Then, the mesoporous silica, as a solid surface with a regular chanals and cavities through electrostatic interactions between polyoxo anions and amine functional groups with positive charge, is used to stabilize the nanocluster as well as the final structure of SBA-15-NH3 +•{Mo36}- formed. As a green and environmentally friendly substrate, natural zeolite is used to stabilize the nanoclusters and the {Mo36}@zeolite obtained. Both heterogeneous catalysts... 

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... 

In this study, antistatic waterborne polyurethane coating containing zirconia nanoparticles is made and applied on 304 stainless steel substrates at weight percentage of 0.66, 1.3, 3, 4.5 and 6% zirconia nanoparticles. For synthesis of hydrophilic isocyanate prepolymer, isocyanate prepolymer is modified by hydrophilic polyethylene glycol with molecular weight 600, 1000 and 4000. For ensuring of modification condition and stability of hydrophilic isocyanate prepolymer in aqua solution, FTIR and stability tests are employed, respectively. In order to create antistatic properties of these coatings, semi - conductive zirconia nanoparticles are used. To improve the distribution of zirconia... 

In this project an enzymatic peroxidase biosensor based on two naono structured material 1-Polyaniline nananofibers 2-Polyethylene glycol-Poly citric acid copolymer was studied for phenol detection.Polyaniline nanofibers and poly ethylene glycol-poly citric acid copolymer were synthetized by chemical polymerization.Electrochemical behaviors of these biosensors were studied using cyclic voltammetry (CV) and amperometric techniques. The amperometric response of the coated electrodes is highly stable with 92% of the initial activity remaining after 5 determinations. These phenol biosensors show an oxidation peak at 0.55V. The amperometric response for phenol biosensor based on Polyaniline... 

Recently, preparation of biofunctionalized nanoparticles with specific magnetic properties has received great attention for medical imaging. Targeting magnetic nanoparticles with high signal in magnetic resonance imaging (MRI) could be a powerful tissue imaging and cellular tracking agent. Main purpose of this research is the synthesis of Mn3O4@polymer composite nanoparticles as a positive MRI contrast agent. Nanoparticles were prepared by modified microwavepolyol and precipitation method with average particle size of 18 and 3nm.Respectivelythe effect of diffrent parameters such as time, surfactant and the presence of water in polyol method and the amount ofpolyethylene glycol as surfactant... 

In this project, Fe3O4 magnetic nanoparticles were prepared by co-precipitation method. For protecting them against oxidation and also avoiding from direct contact between core and additional materials that probably makes unwanted reactions, the surface of nanoparticles were coated by SiO2 layer. Being easy to modify and having the control of interactions between nanoparticles are the advantages of coating nanoparticles with silica. The obtained Fe3O4@SiO2 core-shell nanoparticles were covered by two types of polymer (PPG and PEG). The basis of the composite was characterized by VSM, TGA, SEM, XRD, and FT-IR analytical methods.
The antibacterial activities of Copper, Silver and Gold... 

Semi-crystalline polylactic acid (PLA) and amorphous polymethyl methacrylate can form a soluble and miscible alloy in which the crystalline regions in the polylactic acid act as the fixed and immutable region and amorphous regions of the two polymers act as the changeable region. The two polymers can form a lattice structure with physical connections having shape-memory. So that the deformed polymer returns to its original shape above a certain temperature. These materials are used in sensors, smart materials, and medicine. On the other hand, Polyethylene glycol (PEG) is compatible with polylactic acid (PLA) and it seems that adding it will increase the ductility of polylactic acid (PLA). In... 

In recent years, the tendency to use biodegradable and biocompatible polymer nanoparticles for drug delivery applications has been increasing, the reason for this being the possibility of precise control of the drug release rate, ease of use, and no need for external Surgery after the release of the drug, increases the therapeutic efficiency of the drug and reduces the side effects with its precise transfer. In this research work, drug carrier nanocomposites were prepared from polylactic acid (PLA), polyethylene glycol (PEG) and hydroxyapatite (HAp) and for the controlled release of ciprofloxacin (CIP). It was used to treat bone infections. The drug loading efficiency for nano-carriers was...