185 research outputs found

    The immobilization of polyethylene imine nano and microspheres on glass using high intensity ultrasound

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    The present article describes the creation and immobilization of Polyethylene imine (PEI) capsules on a glass surface. The synthesis and deposition were accomplished by short-time (3 min) one-step reaction. The preparation and immobilization of PEI spheres, was carried out using an environmental friendly method, the ultrasonic emulsification. The ultrasonic technique enables to control size and fulfillment of the internal part of the immobilized PEI spheres. Moreover, the ultrasonic emulsification method showed 100% efficiency in PEI spheres creation, which means no residues of aqueous PEI and oil solvents remained in the reaction flask after the nanosphere's creation. The immobilized PEI spheres have sizes varied from 50 to 500 nm. The PEI spheres were successfully filled either with organic solvent (hydrophobic) or with water (hydrophilic). This method provides us the perspective for future encapsulation of varies molecules which have hydrophobic or hydrophilic nature

    Fragrance release profile from sonochemically prepared protein microsphere containers

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    Protein microspheres have been prepared by sonicating a mixture of pure fragrant oil (amyl acetate (AA)) with an aqueous protein (bovine serum albumin) solution. The prepared protein spheres are nano- to micrometer sized with an encapsulation efficiency of approx. 97% for the AA present on the surface and inside the BSA capsule. Containers were found stable for more than 6 months when stored sealed at 4 °C and 20 °C. For the release profile measurements, we used a simple, automated and direct method. We continuously weighed the encapsulated microspheres and measured the evaporation rates. The release profiles at 15 °C and 25 °C display two different evaporation rates. The higher rate is the sum of a few evaporation rates, including water molecules, while the slower rate is due to the evaporation of pure AA. The changes in the evaporation rates occur upon the collapse of the container. This event coincides with the full evaporation of water. For morphological characterization we dyed the AA with Nile red, and used SEM, ESEM, Cryo-SEM, light microscopy, and confocal laser scanning microscopy measurements

    Sonochemical coating of cotton and polyester fabrics with “Antibacterial” BSA and casein spheres

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    A novel antibacterial coating for cotton and polyester fabrics has been developed by using drug-loaded proteinaceous microspheres made of bovine serum albumin and casein proteins. The microbubbles were created and anchored onto the fabrics (see figure) in a one-step reaction that lasts 3 min. The sonochemically produced “antibacterial fabrics” have been characterized. The efficiency of the sonochemical process in converting the native proteins into microspheres, encapsulating the drug, and coating the fabric has also been studied.This research was carried out as part of the activities of the LIDWINE Consortium, Contract No. NMP2-CT-2006-026741. LIDWINE is an IP Project of the 6th European Customers (EC) Program

    Antibiofilm surface functionalization of catheters by magnesium fluoride nanoparticles

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    The ability of bacteria to colonize catheters is a major cause of infection. In the current study, catheters were surface-modified with MgF2 nanoparticles (NPs) using a sonochemical synthesis protocol described previously. The one-step synthesis and coating procedure yielded a homogenous MgF2 NP layer on both the inside and outside of the catheter, as analyzed by high resolution scanning electron microscopy and energy dispersive spectroscopy. The coating thickness varied from approximately 750 nm to 1000 nm on the inner walls and from approximately 450 nm to approximately 580 nm for the outer wall. The coating consisted of spherical MgF2 NPs with an average diameter of approximately 25 nm. These MgF2 NP-modified catheters were investigated for their ability to restrict bacterial biofilm formation. Two bacterial strains most commonly associated with catheter infections, Escherichia coli and Staphylococcus aureus, were cultured in tryptic soy broth, artificial urine and human plasma on the modified catheters. The MgF2 NP-coated catheters were able to significantly reduce bacterial colonization for a period of 1 week compared to the uncoated control. Finally, the potential cytotoxicity of MgF2 NPs was also evaluated using human and mammalian cell lines and no significant reduction in the mitochondrial metabolism was observed. Taken together, our results indicate that the surface modification of catheters with MgF2 NPs can be effective in preventing bacterial colonization and can provide catheters with long-lasting self-sterilizing properties

    Mesoporous iron-titania catalyst for cyclohexane oxidation

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    This is the first report of using ultrasound radiation for depositing a nanosized catalyst (iron oxide) into the pores of a mesoporous material (titania); the resulting catalyst is used for the oxidation of cyclohexane under mild conditions

    DNA Microspheres Coated with Bioavailable Polymer as an Efficient Gene Expression Agent in Yeasts

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    Gene delivery is one of the steps necessary for gene therapy and for genetic modification. However, delivering DNA into cells is challenging due to its negative charge that leads to repulsion by the negative cell membrane. In the current research, DNA spheres with a DNA encoding to a certain gene were coated with bioavailable polymers, polyethylene imine (PEI) and polycaprolactone (PCL), in a short, one-step sonochemical reaction. The polymers were used in order to neutralize the negative charge of the DNA. Our study shows that the DNA nanospheres not only managed to penetrate the cell without causing it any damage, but also expressed the desired gene inside it

    Novel Technology for Bio-diesel Production from Cooking and Waste Cooking Oil by Microwave Irradiation

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    AbstractIn the transitional process, acid or base catalysts are common technology to produce bio-diesel from waste cooking oil; however, the catalysts only can be use one time. Highly reaction time is requirement for the transitional technology. For improvement these concern issues, this study applied a novel technology to create bio-diesel product from cooking oil and waste cooking oil by microwave irritation. The microwave irradiation can provide strong power and reach reaction temperature in a short time. The SrO catalyst is a heterogeneous catalyst which is not dissolution into any liquid solution therefore, it can be recycling and reusing again.In this research, the optimum conditions were using commercial SrO, 40 to 180seconds reaction time, around 80oC reaction temperature, 6 methanol to oil ratio, and 1000W microwave power output. 99% and 93% biodiesel conversion efficiency for cooking oil and waste cooking oil were reached within in these conditions. The determined specifications of obtained biodiesel according to ASTM D6751 and EN14214 standards were in accordance with the required limits. As a conclusion, the present study indicates that derived fuel promises being an alternative for diesel, and could be used in engines without a major modification due to its qualifications

    Gene silencing by siRNA nanoparticles synthesized via sonochemical method

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    The knowledge that small RNAs can affect gene expression has had a tremendous impact on basic and applied research, and gene silencing is currently one of the most promising new approaches for disease therapy. However, RNAs cannot easily penetrate cell membranes, therefore RNA delivery become one of the major challenges for gene silencing technology. In the current paper we discuss a general approach for converting siRNA molecules into a dense siRNA nanoparticles using environmentally friendly sonochemical method. The RNA nanoparticulation enhance its gene-silencing activity in vascular bovine endothelial as well as in cancer 293T/GFP-Puro cell lines without causing any toxic effect. We show that ultrasonic waves do not lead to RNA degradation or any changes in its chemical structure. Moreover, sonochemically produced siRNA nanoparticles have been shown to be resistant to a variety of environmental stresses including pH levels, enzymes and temperatures, hence solving problem of the short half-life of the RNA molecules. As the siRNA nanoparticles are biocompatibile and biodegradabile, and their RNA release properties may be controlled within limits, sonochemical formation of siRNA nanoparticles represent a new promising approach for generation of functional bionano materials.(undefined

    Proteinaceous microspheres for targeted RNA delivery prepared by an ultrasonic emulsification method

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    In the present work we used sonochemically prepared proteinaceous BSA spheres as a novel RNA-delivery system. The preparation of RNA-loaded BSA spheres was accomplished using an environmental friendly method termed the “ultrasonic emulsification method”. It was demonstrated that ultrasonic waves do not cause the RNA chains to degrade and the RNA molecules remain untouched. The BSA–RNA complex was successfully introduced into mammalian (human) U2OS osteosarcoma cells and Trypanosoma brucei parasites. Using PVA coating of the RNA–BSA spheres we have achieved a significant increase in the number of microspheres penetrating mammalian cells. The mechanism of RNA encapsulation and the structure of the RNA–BSA complex are reported.Ulyana Shimanovich thanks Ministry of Science and Technology, Israel for the "Woman in Science" scholarship (3-8219)
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