Sharif Digital Repository

An efficient and selective drug delivery vehicle for cancer cells can remarkably improve therapeutic approaches. In this study, we focused on the synthesis and characterization of magnetic Ni1−x Cox Fe2 O4 nanoparticles (NPs) coated with two layers of methionine and polyethylene glycol to increase the loading capacity and lower toxicity to serve as an efficient drug car-rier. Ni1−x Cox Fe2 O4 @Methionine@PEG NPs were synthesized by a reflux method then charac-terized by FTIR, XRD, FESEM, TEM, and VSM. Naproxen was used as a model drug and its loading and release in the vehicles were evaluated. The results for loading efficiency showed 1 mg of Ni1−x Cox Fe2 O4 @Methionine@PEG NPs could load... 

In this study Fe3O4/CMC magnetic nanoparticles were synthesized through co-precipitation method. Afterward, laccase from Trametes hirsuta was immobilized onto Carboxymethyl cellulose (CMC)-coated magnetic Fe3O4 nanoparticles by covalent bonding between carboxyl groups of carboxymethyl cellulose and amine group of laccases. Also, the resulted magnetic nanoparticles and immobilized laccase were characterized by Fourier-transform infrared spectroscopy (FTIR), scanning electron microscope (SEM) and dynamic light scattering (DLS) analysis. Moreover, the vital factors in enzyme immobilization, such as contact time, amount of N-hydroxysuccinimide (NHS), and the amount of nanoparticles were... 

Hydroxyapatite nanorods aligned with ultrahigh crystallinity and high-yield were successfully synthesized through a hydrothermal approach. In this experiment, a new composition of cetyltrimethylammonium bromide ((CH 3(CH2)15N+(CH3) 3Br-) was designated as CTAP)/Ca(NO3) 2/ (NH4)2HPO4/NaOH and distilled water under hydrothermal condition, to synthesize single crystal HAp nanorods with diameter of 20 ± 10 nm and length of 80 ± 20 nm, was introduced. Crystal phases were determined by X-ray diffraction (XRD). Scanning electron microscope (SEM) was applied to investigate the morphology. The microstructure of the HAp products were further observed by transmission electron microscope (TEM) and high... 

This study aimed to synthesize methoxy polyethylene glycol propionaldehyde (mPEG20,000-ALD) for the preparation of PEGylated nanoliposomal cisplatin. Nanocarriers such as liposomes are developed for a wide range of drug delivery systems. PEG with high molecular weight (Mw) is used to coat the liposomes. In this study, simulated Fourier transform infrared (FTIR) spectra of mPEG-ALD were obtained using density functional theory (DFT) calculations and then compared with actual FTIR spectrum of mPEG20,000-ALD (Mw = 20 kDa). We found that the intensity of C = O stretching vibration at 1,700 cm-1 related to the carbonyl functional group of mPEG20,000-ALD was very weak. The results of DFT... 

Natural compounds containing polysaccharide ingredients have been employed as candidates for treatment of skin tissue. Herein, for the first time, electrospinning setup was proposed to fabricate an efficient composite nanofibrous structure of Beta vulgaris (obtained from Beet [Chenopodiaceae or Amaranthaceae]) belonged to polysaccharides and an elastic polymer named nylon 66 for skin tissue engineering. Both prepared scaffolds including noncomposite and composite types were studied by Scanning electron microscope (SEM), Fourier transform infrared (FTIR) spectroscopy, mechanical assay, and contact angle. Scanning electron microscope examinations have approved the uniform and homogeneous... 

Polystyrene resin was functionalized by diethanolamine for the efficient removal of p-toluenesulfonic acid (p-TSA) from aqueous solution. Functionalized adsorbent (DEA-PS) was characterized by elemental analysis, Fourier transform infrared spectroscopy, point of zero charge measurement and field-emission scanning electron microscopy. According to the results, maximum removal of p-TSA was observed at the pH range of 2.5-5. The adsorption kinetics of p-TSA onto DEA-PS was represented by pseudo-first-order model and the equilibrium data followed Langmuir model well. The adsorption process was endothermic and spontaneous, along with the positive change of entropy. The regeneration of DEA-PS was... 

In the present study, thermally oxidized nanodiamond (OND) was first modified non-covalently with dodecylamine (DDA) as corrosion inhibitor. In this respect, reactive primary amine of DDA molecule with high isoelectric point (IEP) could interact easily with negative charge carboxylic acid groups of OND. Fourier transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA) proved that OND nanoparticle was successfully functionalized by DDA up to approximately 5 wt% grafting contnet. Both OND and dodecylamine modified OND (DND) were loaded in epoxy (EP)/polyamine hardener matrix at the same concentration of 1 wt% and applied on mild steel substrate. Morphology of EP-DND and... 

Systemic chemotherapy has lost its position to treat cancer over the past years mainly due to drug resistance, side effects, and limited survival ratio. Among a plethora of local drug delivery systems to solve this issue, the combinatorial strategy of chemo-hyperthermia has recently received attention. Herein we developed a magneto-thermal nanocarrier consisted of superparamagnetic iron oxide nanoparticles (SPIONs) coated by a blend formulation of a three-block copolymer Pluronic F127 and F68 on the oleic acid (OA) in which Curcumin as a natural and chemical anti-cancer agent was loaded. The subsequent nanocarrier SPION@OA-F127/F68-Cur was designed with a controlled gelation temperature of... 

Nowadays, environmental hazards caused by plastic wastes are a major concern in academia and industry. Utilization of biodegradable polymers derived from renewable sources for replacing common petroleum-based plastics is a potential solution for reducing the problem. In this regard, starch has become one of the most promising alternatives to non-biodegradable polymers for depleting plastic waste thanks to its low expense, abundance, renewability and biodegradability. However, the main drawbacks of starch are its poor processability, weak mechanical properties and severe hydrophilicity. In this work, thermoplastic starch (TPS) samples have been prepared using glycerol and sorbitol as... 

The aim of this work is to investigate the effect of molybdenum disulfide on tribological properties of Ultra-high-molecular-weight polyethylene (UHMWPE). UHMWPE/MoS2 nano-composites were prepared using in-situ polymerization and Ziegler-Natta catalytic system. Studies showed that, in order to obtain the optimum tribological properties, interlayer distance between nanosheets should be as high as possible. Therefore, the nanosheets were subjected to oxidation using the required oxidants followed by thermal shock and ultrasound. Fourier-transform infrared spectroscopy (FTIR) analysis was used to determine the formation of functional groups which indicate the formation of S═O bond in the... 

Metal organic frameworks (MOFs) UiO-66 (UiO stands for University of Oslo) and NH2-UiO-66 were prepared and characterized as sorbent (antidotal agents) for curcumin (CUR) adsorption. The structure of products were characterized by X-ray powder diffraction (XRD), Field emission scanning electron microscopy (FESEM), thermogravimetric analysis (TGA), Attenuated Total Reflectance-Fourier transform infrared spectroscopy (ATR-FTIR), and N2 adsorption–desorption measurements. FESEM showed NH2-UiO-66 displayed symmetrical crystals with triangular base pyramid morphology, with the particle size around 100 nm and uniform size distribution. Adsorption capacities of CUR/MOFs with different mass ratios... 

Aryl halides and especially inactive aryl chlorides were coupled to benzenoid aromatic rings in a Suzuki–Miyaura coupling reaction in the absence of organic solvents and toxic phosphine ligands. The reaction was catalysed by a recoverable magnetic nanocatalyst, Pd@Fe3O4, in aqueous media. This method is green, and the catalyst is easily removed from the reaction media using an external magnetic field and can be re-used at least 10 times without any considerable loss in its activity. The catalyst was characterized using scanning and transmission electron microscopies, thermogravimetric analysis, inductively coupled plasma spectroscopy, Fourier transform infrared spectroscopy, CHN analysis,... 

Vanadium supported on spinel cobalt ferrite nanoparticles was synthesized and characterized using Fourier transform infrared spectroscopy, X-ray diffraction, energy-dispersive X-ray analysis and transmission electron microscopy. For the first time, the prepared material was used for the catalytic degradation of methylene blue as an organic dye in the presence of hydrogen peroxide as a green oxidant and NaHCO3 as a co-reagent at room temperature. The dependency of removal percentage on various parameters such as amount of catalyst, pH, reaction time and temperature and the effect of radical scavenging agents were studied. Finally, recoverability and reusability of the vanadium supported on... 

The contribution of electrospun nanofibrous membranes (e.NFMs) in the biosensing platforms opens up a new prospect for the invention of faster and more sensitive analytical devices. In this paper, we utilized e.NFM of polyethersulfone (PES) as a solid substrate for the protein immobilization through two different approaches: physical and covalent. Scanning electron microscopy (SEM) and Fourier-transform-infrared (FTIR) tests were performed to study the effect of plasma treatment on protein immobilization efficacy. Moreover, taking advantage of ELISA technique, the influence of different parameters, namely, nanofibers diameter, membrane thickness, plasma treatment time, an incubation time of... 

The complexes PdII(qcq)(OAc) and PtII(qcq)Cl have been synthesized using environmentally benign synthesized ligands and characterized by elemental analyses: Fourier transform infrared spectroscopy, UV–visible spectroscopy, 1H NMR spectroscopy, and X-ray diffraction. The catalytic activity of the complex was assessed, in different media, for the Mizoroki–Heck coupling reaction for typical aryl halides and terminal olefins under aerobic conditions. Since the base and the solvent were found to influence the efficiency of the reaction, reaction conditions, temperature, time, and the amount of K3PO4 and a mixture of H2O/PEG, were optimized. We found, for the Mizoroki–Heck reaction coupling less... 

We report a novel strategy for the synthesis of magnetic nanocomposite for highly efficient catalysis. Poly(glycidyl methacrylate) (PGMA) chains were grafted to the surface of magnetic nanoparticles (MNPs) through surface-initiated reversible addition-fragmentation chain transfer polymerization. Then, the oxirane rings in the PGMA chains were opened with 2,6-diamino pyridine (DAP) molecules as ligands to prepare the solid support. Finally, this magnetic nanocomposite was used for the immobilization of gold nanoparticles. Fourier-transform infrared spectroscopy, X-ray diffraction, thermogravimetric analysis, transmission electron microscopy, scanning electron microscopy, gel permeation... 

A novel optimized chelating hydrogel was synthesized via graft copolymerization of acrylamide and 2-hydroxyethyl methacrylate (as two-dentate chelating co-monomer) onto salep (a multicomponent polysaccharide obtained from dried tubers of certain natural terrestrial orchids) using N,N′-methylenebisacrylamide as a crosslinker and ammonium persulfate as an initiator. Reaction parameters (N,N′-methylenebisacrylamide and ammonium persulfate amounts as well as acrylamide/2-hydroxyethyl methacrylate weight ratio) affecting the water absorption of the chelating hydrogel were optimized using a systematic method to achieve a hydrogel with high swelling capacity as possible. Heavy metal ion adsorption... 

A new heterogeneous copper catalyst was synthesized by immobilization of copper ions onto magnetic nanoparticles with a new ligand based on triazole. The catalyst was characterized using scanning and transmission electron microscopies, atomic absorption and Fourier transform infrared spectroscopies, and thermogravimetric, elemental and energy-dispersive X-ray analyses. The results confirmed that a good level of organic groups was immobilized on the magnetic nanoparticles. Huisgen cycloaddition reaction was chosen as a model reaction for the investigation of catalyst activity under green conditions. Phenylacetylene and benzyl bromide derivatives were used for the synthesis of triazoles. The... 

Chitosan films have a great potential to be used for wound dressing and food-packaging applications if their physicochemical properties including water vapor permeability, optical transparency, and hydrophilicity are tailored to practical demands. To address these points, in this study, chitosan (CS) was combined with polyvinylpyrrolidone (PVP) and graphene oxide (GO) nanosheets (with a thickness of ∼1 nm and lateral dimensions of few micrometers). Flexible and transparent films with a high antibacterial capacity were prepared by solvent casting methods. By controlling the evaporation rate of the utilized solvent (1 vol % acidic acid in deionized water), self-organization of GO in the... 

Poly(vinyl alcohol) (PVA) is a biocompatible polymer which can be physically crosslinked by Borax to form hydrogel. PVA-Borax (PB) hydrogel is a promising candidate for drug delivery system. Therefore, it is necessary to find the quantitative relationship between drug release rate and network structure of PB hydrogels to predict and control drug release rate. In this work, at first step the optimum ratio of Borax: PVA was determined by studying the interactions between PVA chains and Borax molecules by means of Fourier transform infrared spectroscopy, while viscoelastic properties of prepared PB hydrogels were measured in the oscillatory shear flow field. In the following, curcumin as a...