جستجوی مقالات مرتبط با کلیدواژه "magnetite nanoparticle" در نشریات گروه "پزشکی"

Current research had successfully encapsulated magnetic nanoparticles (MNP) with selective estrogen receptor drug tamoxifen citrate (TAM) using Poly (d,l-lactice-co-glycolide acid) (PLGA 75:25) via oil in water emulsion technique. TAM is a good example of a drug that is difficult to dissolve. TAM is currently approved for the treatment of hormone-sensitive and early-stage breast cancer as an adjuvant endocrine therapy. The majority of the prescription medicine in today market is made up of poorly soluble, bioavailable, and quickly metabolized and eliminated drug which is a continuously challenges up to these days. Therefore, it is imperative to overcome this disadvantages by encapsulating TAM inside PLGA together with MNP for improved drug delivery. The MNP coated with oleic acid (OA) was synthesized using co-precipitation method and it is known as OAMNP. The fabricated nanohybrid is known as TAM-PLGA-OAMNP where the TAM was encapsulated together with OAMNP within PLGA. XRD results showed that OAMNP is Fe3O4. FTIR spectra revealed that the TAM was successfully encased into the PLGA structure. TAM-PLGA-OAMNP average size is about 131 ± 28 nm as shown in TEM results. The nanohybrid nanoparticles showed the absence of hysteresis loop indicative of superparamagnetic properties.

Many patients die due to vascular, gastrointestinal lumen problems, and coronary heart diseases. Synthetic vessels that are made of biodegradable-nanofiber polymers have significant properties such as proper biodegradability and efficient physical properties such as high strength and flexibility. Some of the best options for supporting cells in soft tissue engineering and design are applications of thermoplastic polyurethane polymer in the venous tissue. In this study, the first nanoparticle-reinforced polymeric artificial prosthesis was designed and tested to be used in the human body.

In this study, artificial gastrointestinal lumen were fabricated and prepared using a 3D printer. To improve cell adhesion, wettability properties and mechanical stability of elastin biopolymer with magnetic nanoparticles (MNPs) as well as single-walled carbon nanotubes (SWCNT) were prepared as separate filaments. MNPs were made in 5–7 mm sizes and then examined for mechanical, biological, and hyperthermia properties. Then, the obtained results of the gastrointestinal lumen were simulated using the Abaqus software package with a three-branch. The results were evaluated by X-ray diffraction (XRD) and scanning electron microscopy (SEM) for morphology and phase analysis.

The obtained results of the designed vessels showed remarkable improvement in mechanical properties of the SWCNT vessels and hyperthermia properties of the vessels containing the MNPs. The results of computational fluid dynamics (CFD) analysis showed that the artificial vessels had lower shear stress at the output.

Five-mm MNP containing vessels showed noticeable chemical and biological properties along with ideal magnetic results in the treatment of thrombosis and vascular obstruction.

Advantages of using porous bio-nanocomposite scaffolds for maxillofacial fracture application and optimizing the internal surfaces of synthetic grafts using nanotechnology can accelerate the bone cell adhesion, mechanical properties and absorption rates. There are various studies that have been performed on porous scaffold, especially for the fractured and destroyed parts of the facial bones. The aim of this study was to investigate the experimental and numerical analysis of the porous scaffold, which undertakes static and dynamic loading conditions.

The maxillofacial bone was modeled using the solid works software, and then it was inserted into the Abaqus software to achieve a more precise model that utilizes an isotropic linear substance. Thereafter, a proper micromechanical model reported evaluating the elastic modulus response on porosity value using various models. Additionally, an experimental analysis was conducted on a new calcium silicate (CS) bioceramic reinforced with magnetite nanoparticles (MNPs) using the space holder technique coated with the gentamicin drug loaded on gelatin polymer. The response of the bio-nanocomposites shape, which corresponds to different MNPs’ weight fractions, was determined using the scanning electron microscopy (SEM) and X-ray diffraction (XRD) techniques.

The analysis of the scaffold implant showed that it is tightened at a torque of stiffness of 3 mm in the implant, which leads to high mechanical tension. The results showed that the elastic modulus of the nanocomposites increased from 60±5 MPa to 145±5 MPa with increasing 15 wt% MNPs to the calcium silicate nanoparticles.

The results indicated that addition of 15 wt% MNPs to the based bioceramics increased both compression strength and decrease the porosity value.

Bioactive silicate ceramics have favorable features for applying as off-the-shelf bone and artificial tissue. Calcium silicate can enhance the generation of an immediate bond with host bone without an intervening rough surface in the bone layer. However, the silicate bioceramics have some drawback regarding their mechanical properties and chemical stabilities.
In this study, magnetite nanoparticles (MNPs) as reinforcement were added to the three silicate bioceramics to investigate the physical and mechanical properties as well as their magnetic behavior as a case study and compare with other calcium silicate nanocomposite which are excellent candidates for hyperthermia applications. Then the artificial neural network (ANN) applied to the previous data to predict the mechanical and biological behavior of the bio-nanocomposite as output parameters. A predicted model was enhanced using ANN to measure the optimum size and reinforcement amount of the magnetite bio-nanocomposite. The results of the fabricated bio-nanocomposite were extracted experimentally corresponding to different MNPs weight fractions compared to the predicted model.
The X-ray diffraction (XRD), scan electron microscopy (SEM) technique were used to compare the porosity and porous tissue microstructure. Thereafter, an analytical solution is presented to express explicitly the physical and mechanical responses of the bulk/scaffold bio-nanocomposite.
The obtained results showed the potential application of these calculations and analyses in a wide range of numerical studies. The comparison presented within the test and predicted values showed that the modeling outcomes were close to testing values.

Magnetite (Fe3O4 and NiO) nanoparticles with a size range of 40–60 nm were prepared by sol-gel technique in nano and micro reverse micelles (water- in-oil). The surface properties, size, morphology and crystallographic structure of Fe3O4 and NiO particles are characterized by means of X-ray diffraction, transmission electron microscope and scanning electron microscope which will give much valuable information about these materials. In addition, synthesis of nanoparticles can be easily implemented because it is simple and environmentally friendly.

Zincite (ZnO) nanoparticles are usually prepared by decomposition of zinc acetate, hot injection and heating-up method. Microbial nanoparticle production has been developed recently, since they are clean, nontoxic and cheap. Bacteria are known as environmentally friendly nanoparticle factories using cheap, renewable carbon sources. Nanometer-sized nanoparticles are talented for different applications. For example, semiconductor nanoparticles such as Sphalerite (ZnS) are used as fluorescence probes for labeling of biological tissues. These days, magnetic nanoparticles are applied routinely in magnetic resonance imaging (MRI) as contrast-enhancement agents. Also, nano ZnO is useful in petrochemical industries.. The aim of this study was to produce nanoparticles such as ZnO, ZnS, and Zn by using biofilm of a resistant bacterium (i.e. Pseudomonas stutzeri) on a piece of pure zinc.. P. stutzeri strain CS-2 was isolated from enriched soil containing methyl tertiary butyl ether (MTBE). Since the bacterium has many metal resistance genes, it was a good candidate for producing nanoparticles. A piece of pure zinc metal, sized 3.1cm was put on a solid medium (nutrient agar). The biofilm was isolated and analyzed by X-Ray diffractometer (XRD). The optimum environmental condition for producing nanoparticles was investigated. Moreover, antibacterial activity as well as magnetic property of the produced nanoparticles was studied. Finally, PCR reaction for specific PST gene was done.. Analysis by XRD showed 78.1% ZnO (sized 24 nm), 2.5% Zn (sized 44.88 nm) and 4.8% ZnS (sized 12 nm) produced by P. stutzeri. The nanoparticles showed anti-bacterial activity against some of the Gram positive and negative bacteria. In addition, the nanoparticles showed magnetic properties. The best condition for nano zinc production was at pH 7, in the light and at 37 °C. CzcC gene with 399Kb was detected from the isolated P. stutzeri.. Although previous studies have shown that P. stutzeri is able to produce silver nanoparticles in silver salt solution, but in this study, for the first time ZnO, ZnS, and Zn nanoparticles were detected on a biofilm of zinc metal. Isolation of these nanoparticles by this method is very cost effective, non-toxic, clean and compatible to Eco (green chemistry)..