76 research outputs found

    Evaluation of effective parameters on fabrication of BSA nanoparticles

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    Coacervation technique was implemented in fabrication of BSA nanoparticle for the purpose of drug delivery system. Nanoparticle was purified with 48,800 g centrifuge, and then followed by dialysis, micro and ultra filtration. The fabricated nanoparticles were subjected to physical, morphological and biochemical characterization. The analyzed samples by SEM and AFM proved the semi-spherically shape of the particles whilst the size distribution was measured by photon correlation spectroscopy. Fourier transforms infra-red spectroscopy (FTIR) spectrum indicated that the fabricated nanoparticles were pure. The impact of various parameters upon the particle size was extensively investigated. The concentration of glutaraldehyde at fixed temperature had absolutely no significant effect on the size of particles. The affecting parameter was modeled to predict the size of nanoparticle. At low temperature (4{degree sign}C), the nanoparticle size of 89.3nm was fabricated with pure BSA concentration of 20 mg.ml-1

    Synthesis and characterization of a novel Fe3O4-SiO2@Gold core-shell biocompatible magnetic nanoparticles for biological and medical applications

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    Objectives: The study of core-shell magnetic nanoparticles has a wide range of applications because of the unique combination of the nanoscale magnetic core and the functional shell. Characterization and application of one important class of core-shell magnetic nanoparticles (MNPs), i.e., iron oxide core (Fe3O4/¿-Fe2O3) with a silica shell and outer of gold (Fe3O4-SiO2@Gold (FSG)) in Boron Neutrons Capture Therapy (BNCT) highlighted. The main problem dealing with cancer cells is that the tumor and normal cells ones are mixed without a map of the boron accumulation. Methods: Areas specifically discussed in this report include the possibility of a FSG mediated by liposome as the boron carriers for the transfer of boron compound to tumor tissue. Furthermore, folate receptor was considered as an appropriate substrate that has great potential to attach to tumor on the surface of cancer cells. The present work aimed to study boron biodistribution in the muscle cancer animal model in Bagg Albino (BALB/c) mice employing PEGylated liposome-encapsulated FSG formulations. Results: The predetermined boron concentration was obtained to be 20-35 mg 10B/g. Samples of the tumor tissue, such as kidney, liver, lung, heart, skin, spleen, brain, stomach, and bone were taken as post-administration at different times to measure boron content by Inductively Coupled Plasma (ICP) analysis. The results showed the existence of GLUT-5 expression as an erythrocyte-type glucose transporter protein in a wide variety of tumor cells. Conclusions: Fe3O4-SiO2 nanoparticles are highly biocompatible with biological materials and gold shell also imparts the magnetic nanoparticles with many intriguing functional propertiesPeer ReviewedPostprint (published version

    Carbon dioxide captured by multi-walled carbon nanotube and activated charcoal: A comparative study

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    this study, the equilibrium adsorption of CO2 on activated charcoal (AC) and multi-walled carbon nanotube (MWCNT) were investigated. Experiments were performed at temperature range of 298-318 K and pressures up to 40 bars. The obtained results indicated that the equilibrium uptakes of CO2 by both adsorbents increased with increasing pressure and decreasing temperature. In spite of lower specific surface area, the maximum amount of CO2 uptake achieved by MWCNT at 298K and 40 bars were twice of CO2 capture by AC (15 mmol.g-1 compared to 7.93 mmol.g-1). The higher CO2 captured by MWCNT can be attributed to its higher pore volume and specific structure of MWCN T such as hollowness and light mass which had greater influence than specific surface area. The experimental data were analyzed by means of Freundlich and Langmuir adsorption isotherm models. Following a simple acidic treatment procedure increased marginally CO2 capture by MWCNT over entire range of pressure, while for AC this effect appeared at higher pressures. Small values of isosteric heat of adsorption were evaluated based on Clausius-Clapeyron equation showed the physical nature of adsorption mechanism. The high amount of CO2 capture by MWCNT renders it as a promising carrier for practical applications such as gas separation

    Melissa officinalis extraction with nanoencapsulation By chitosan as an ecofriendly compound

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    The bioactive compounds in extracts are prone to degradation by oxidation, heat, or light. Nanoencapsulation is one of the best techniques to keep the properties of these chemical compounds. The aim of this study was the extraction of Melissa officinalis (MO) and nanoencapsulation of the extract via chitosan as a biodegradable polymer. In this research, extraction of MO was investigated using various extraction methods and nanoencapsulation with MO extract was carried out via ionic gelation technique. The effectiveness of the extracts was evaluated by measuring the total phenolic content (TPC), antioxidant activity, and extraction efficiency of the solid contents. The highest efficiency was achieved for microwave-assisted extraction with the utmost values in each parameter. (TSC) was 22.81% and amounts of the TPC and antioxidant activity were 311.94 mg Gallic acid and 36 mg diphenyl picryl hydrazyl (DPPH) per 1g of the plant, respectively.  Morphology study by field emission scanning electron microscopy (FE-SEM) indicated spherical shape nanoparticles with a diameter of 25nm. The size of the nanoparticles was evaluated by the Dynamic Light Scattering (DLS) technique for various concentrations of the used extracts in the encapsulation process. For 1.0, 3.0, and 5.0 mg /mL concentration, mean diameters were 24, 118, and 145 nm, respectively. Results indicated that microwave-assisted extraction was the best extraction method for MO and the encapsulation of MO extract could be created successfully with different particle sizes for the protection of bioactive compounds. Since MO is a beneficial herbal plant, the development of this research is recommended

    Morphological Study of Hybrid Nanofibers Based on Polyaniline/Carbon Nanofibers Prepared by Electrospinning Method

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    Uniform and thin polyaniline/carbon nanofiber (PANi/CNF) hybrid nanofibers has been prepared using electrospinning method. Three polymer solutions with different components were examined for synthesis of PANi/CNF electrospun nanofibers. The SEM technique and FT-IR analysis were used to characterize the hybrid nanofibers. Effects of process parameters and used materials on the morphology and diameter of PANi/CNF hybrid nanofibers were experimentally studied in the each of polymer solutions. The resulting nanofibers obtained from the polymer solution containing commercial PANi with combination of dichloroacetic acid (DCAA) and 2-acrylamido-2-methyl-1-propane sulfonic acid (AMPSA) were more uniform and thinner than prepared fibers from other polymer solutions. The average diameter of synthesized hybrid nanofibres using the polymer solution containing AMPSA/DCAA was about 100 nm

    EIDA: An Energy-Intrusion aware Data Aggregation Technique for Wireless Sensor Networks

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    Energy consumption is considered as a critical issue in wireless sensor networks (WSNs). Batteries of sensor nodes have limited power supply which in turn limits services and applications that can be supported by them. An efcient solution to improve energy consumption and even trafc in WSNs is Data Aggregation (DA) that can reduce the number of transmissions. Two main challenges for DA are: (i) most DA techniques need network clustering. Clustering itself is a time and energy consuming procedure. (ii) DA techniques often do not have ability to detect intrusions. Studying to design a new DA technique without using clustering and with ability of nding intrusion is valuable. This paper proposes an energy-intrusion aware DA Technique (named EIDA) that does not need clustering. EIDA is designed to support on demand requests of mobile sinks in WSNs. It uses learning automata for aggregating data and a simple and effective algorithm for intrusion detection. Finally, we simulat

    Human chorionic gonadotropin attenuates amyloid-β plaques induced by streptozotocin in the rat brain by affecting cytochrome c-ir neuron density

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    Objective(s): Amyloid β plaques, in Alzheimer’s disease, are deposits in different areas of the brain such as prefrontal cortex, molecular layer of the cerebellum, and the hippocampal formation. Amyloid β aggregates lead to the release of cytochrome c and finally neuronal cell death in brain tissue. hCG has critical roles in brain development, neuron differentiation, and function. Therefore, we investigated the effect of hCG on the density of the congophilic Aβ plaque and cytochrome c-ir neurons in the hippocampus, prefrontal cortex, and cerebellum of Streptozotocin (STZ)-treated rats. Materials and Methods: Alzheimer model in rats (except the control group) was induced by streptozotocin (3 mg/kg, Intracerebroventricularly (ICV)). Experimental group rats received streptozotocin and then different doses of hCG (50, 100, and 200 IU, intraperitoneally) for 3 days. 48 hr after last drug injection and after histological processing, the brain sections were stained by congo red for congophilic amyloid β plaques and cytochrome c in the hippocampus, prefrontal cortex, and cerebellum were immunohistochemically stained. Results: Density of congophilic Aβ plaques and cytochrome c-immunoreactive neurons was significantly higher in ICV STZ treated rats than controls. Treatment with three doses of hCG significantly decreased the density of congophilic Aβ plaques and cytochrome c-immunoreactive neurons in the rat hippocampus, prefrontal cortex, and cerebellum in ICV STZ-treated rats (

    Flexible Electronics: A Protein‐Based, Water‐Insoluble, and Bendable Polymer with Ionic Conductivity: A Roadmap for Flexible and Green Electronics (Adv. Sci. 5/2019)

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    Contains fulltext : 215371.pdf (publisher's version ) (Open Access)Proteins present an ecofriendly alternative to many of the synthetic components currently used in electronics. They can therefore in combination with flexibility and electroactivity uncover a range of new opportunities in the field of flexible and green electronics. In this study, silk-based ionic conductors are turned into stable thin films by embedding them with 2D nanoclay platelets. More specifically, this material is utilized to develop a flexible and ecofriendly motion-sensitive touchscreen device. The display-like sensor can readily transmit light, is easy to recycle and can monitor the motion of almost any part of the human body. It also displays a significantly lower sheet resistance during bending and stretching regimes than the values typically reported for conventional metallic-based conductors, and remains fully operational after mechanical endurance testing. Moreover, it can operate at high frequencies in the kilohertz (kHz) range under both normal and bending modes. Notably, our new technology is available through a simple one-step manufacturing technique and can therefore easily be extended to large-scale fabrication of electronic devices
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