The Experts below are selected from a list of 42420 Experts worldwide ranked by ideXlab platform
Nurettin Sahiner - One of the best experts on this subject based on the ideXlab platform.
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One step poly(rutin) Particle Preparation as biocolloid and its characterization
Materials science & engineering. C Materials for biological applications, 2014Co-Authors: Nurettin SahinerAbstract:Poly(rutin) p(RT) Particles were prepared for the first time via a simple microemulsion polymerization/crosslinking method using l-α lecithin as surfactant, cyclohexane as organic phase and glycerol diglycidyl ether (GDE) as a crosslinking agent. Highly negatively charged p(RT) Particles, -48.2 mV, were obtained due to phenolic groups on the Particles. It was also confirmed that p(RT) Particles are thermally more stable than RT and degradable in PBS at pH7.4., e.g., 11 wt.% can degrade in 1 day and little further degradation was observed over 9 days. The prepared p(RT) Particles showed insignificant antibacterial characteristics against common bacteria such as Escherichia coli ATCC8739, Staphylococcus aureus ATCC6538, and Bacillus subtilis ATCC6633 whereas the RT molecules showed significantly better antibacterial characteristics even at low concentrations. Moreover, p(RT) Particles were demonstrated for use as drug delivery devices by loading rosmarinic acid (RA) as model drug and showed release capability for up to 6 days by releasing 85% of the loaded RA. Intriguingly, p(RT) Particles illustrated enhanced fluorescent properties providing great potential for fluorescent active antioxidant and antibacterial materials in biomedical use.
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One step poly(quercetin) Particle Preparation as biocolloid and its characterization
Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2014Co-Authors: Nurettin SahinerAbstract:Abstract Quercetin (QC) was reacted with glycerol diglycidyl ether (GDE) to obtain poly(quercetin) Particles (p(QC)) for the first time via a simple microemulsion polymerization/crosslinking method using l -α lecithin as surfactant and cyclohexane as organic phase. The prepared p(QC) Particles were highly negatively charged (−48.2 mV), were thermally more stable in comparison to QC and degradable in PBS at pH 7.4., e.g., 10 wt% can degrade in about 15 h. The prepared p(QC) Particles showed antibacterial characteristics against common bacteria such as Bacillus subtilis ATCC 6633, Escherichia coli ATCC 8739 and Staphylococcus aureus ATCC 25323. Additionally, p(QC) was found to have significant antioxidant properties that is equivalent to 82.5 ± 9.6 mg/L gallic acid. More interestingly p(QC) Particles retain some of their fluorescence and can be used both as antibacterial and antioxidant materials providing great potential for biomedical use.
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a versatile hydrogel template for metal nano Particle Preparation and their use in catalysis
Polymer, 2011Co-Authors: Sultan Butun, Nurettin SahinerAbstract:Abstract We report the synthesis of a novel bulk hydrogel based on acrylamidoglycolic acid (AAGA) and its use as a template in the Preparation of different metal nanoParticles. Furthermore, we demonstrate the efficient utilization of p(AAGA) composite hydrogel as a reactor vessel in the reduction of an organic contaminant, 4-nitrophenol (4-NP) to 4-aminophenol (4-AP). The swelling characteristics of the hydrogel at different pH and different concentrations of salts (NaNO 3, NaCI) were studied, and experimental molecular mass between crosslink ( M c ) values was calculated. Experimental parameters that affect the 4-NP reduction rate such as temperature, amount of catalysis, co-catalysis, concentrations of 4-NP and of NaBH 4 were investigated. The kinetics of the reduction reaction under different reaction conditions was also evaluated to determine the activation parameters. Activation energy for the reduction of 4-NP was 33.783 kJ mol −1 and p(AAGA)–Ag composites possessed 88% activity at the end of five repetitive uses.
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In situ metal Particle Preparation in cross-linked poly(2-acrylamido-2-methyl-1-propansulfonic acid) hydrogel networks
Colloid and Polymer Science, 2006Co-Authors: Nurettin SahinerAbstract:Anionic hydrogels of poly(2-acrylamido-2-methyl-1-propansulfonic acid) (p(AMPS)) were prepared with a different amount of cross-linker extent and used for in situ Preparation of magnetic and metal Particles. The metal Particles with various sizes were obtained inside the three-dimensional polymer matrixes by absorption of the corresponding metal ions from their aqueous solutions followed by the reduction in the presence of strong reducing agent. In addition to iron Particles, cobalt, nickel, copper nanoParticles, and CdS, quantum dot has been prepared by utilizing hydrogel matrix as a template for inorganic/organic composite synthesis. It was observed that the amount of cross-linkers (0.5%, 0.75%, and 1% with respect to monomer mole ratio) used in this study for bare p(AMPS) has not significantly influenced the morphology of the hydrogels or the size of the iron Particles while having great effect on swelling of p(AMPS) hydrogels in water. Copolymeric hydrogels of AMPS with acrylamide in different composition were also prepared. Thermogravimetric analysis and transmission electron microscopy results showed that the AMPS content of the copolymeric hydrogel has great impact on both the metal ion loading capacity and the size of the resultant metal Particles.
Wang Zhi-xiang - One of the best experts on this subject based on the ideXlab platform.
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Application of Supercritical Fluid Anti-solvent Crystallization Technique in the Field of Pharmaceutical Particle Preparation
Progress in Pharmaceutical Sciences, 2007Co-Authors: Wang Zhi-xiangAbstract:The physical properties and crystallizing operation characteristics of supercritical fluid,the machanism and operating mode of supercritical fluid anti-solvent process and the application in pharmaceutical Particle Preparation thereof,including Preparation of Particles of biopharmaceuticals and antibiotics and pharmaceutical composite microspheres or microcapsules,were summarized.
Adam Bohr - One of the best experts on this subject based on the ideXlab platform.
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pharmaceutical microParticle engineering with electrospraying the role of mixed solvent systems in Particle formation and characteristics
Journal of Materials Science: Materials in Medicine, 2015Co-Authors: Adam Bohr, Jakob Kristensen, Mark Dyas, Eleanor Stride, Stefania Baldursdottir, Mohan Edirisinghe, Mingshi YangAbstract:MicroParticles of Celecoxib, dispersed in a matrix of poly(lactic-co-glycolic acid) (PLGA), were pre- pared by electrospraying using different solvent mixtures to investigate the influence upon Particle formation and the resulting Particle characteristics. Mixtures consisting of a good solvent, acetone, and an anti-solvent, methanol, for PLGA were studied in different ratios. Properties of the spraying solutions were examined and the resulting mi- croParticles were characterized with regard to size, mor- phology, porosity, solid state form, surface chemistry and drug release. Particle formation was strongly influenced by the polymer molecular conformation during droplet for- mation and by the anti-solvent concentration during droplet drying. A strong correlation was found between Particle morphology and the solubility of the polymer in the solvent mixtures. The lack of chain entanglements in droplets containing anti-solvent resulted in compact polymer conformation and grain-like Particle morphology. Further, the early precipitation of polymer and low chain interaction with increasing content of anti-solvent resulted in surface enrichment of drug (from 10 and 20 % up to 41 and 57 % respectively), also demonstrated by the increasingly higher drug release rates. The results demonstrate the importance of solvent composition in Particle Preparation and indicate potential for exploiting this dependence to improve phar- maceutical Particle design and performance.
Mehdi Rahiminasrabadi - One of the best experts on this subject based on the ideXlab platform.
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facile synthesis of zinc carbonate and zinc oxide nanoParticles via direct carbonation and thermal decomposition
Ceramics International, 2013Co-Authors: Mojtaba Shamsipur, Mir Mahdi Zahedi, Seiedeh Somayyeh Hajimirsadeghi, Seied Mahdi Pourmortazavi, Mehdi RahiminasrabadiAbstract:Abstract Synthesis of ultrafine zinc carbonate and zinc oxide powders using direct precipitation and thermal decomposition of the precursor was investigated. NanoParticles of ZnCO3 were prepared by the direct precipitation method with Zn(NO3)2 and Na2CO3 as raw materials. The precipitation process as a popular, facile, controllable and cost-effective method was used to produce insoluble inorganic salts. Therefore, it was very important to improve capability and quality of the process for controlling the product Particle size by setting the optimal precipitation reaction parameters. In this research, the parameter design of the Taguchi method was applied to set the optimal parameters of precipitation process for zinc carbonate nano-Particle Preparation. The reaction conditions such as zinc and carbonate ion concentrations, flow rate of reagent addition and reactor temperature were optimized by orthogonal array design, OA9. The effect of these factors on the size of ZnCO3 nanoParticles was quantitatively evaluated by the analysis of variance (ANOVA). The results showed that ZnCO3 nanoParticles can be synthesized via direct carbonation process by controlling zinc and carbonate ion concentrations and flow rate of reagent addition. The experimental results for Preparation of nano-Particles of ZnCO3 showed that the minimum size was about 15 nm and the maximum was about 70 nm. In the next step of this study, an efficient one-step thermal decomposition method was described for Preparation of ZnO nanoParticles from zinc carbonate precursor. The prepared ZnCO3 and ZnO Particles were characterized using X-ray diffraction (XRD), SEM, FT-IR and thermal analysis techniques.
Seied Mahdi Pourmortazavi - One of the best experts on this subject based on the ideXlab platform.
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facile synthesis of zinc carbonate and zinc oxide nanoParticles via direct carbonation and thermal decomposition
Ceramics International, 2013Co-Authors: Mojtaba Shamsipur, Mir Mahdi Zahedi, Seiedeh Somayyeh Hajimirsadeghi, Seied Mahdi Pourmortazavi, Mehdi RahiminasrabadiAbstract:Abstract Synthesis of ultrafine zinc carbonate and zinc oxide powders using direct precipitation and thermal decomposition of the precursor was investigated. NanoParticles of ZnCO3 were prepared by the direct precipitation method with Zn(NO3)2 and Na2CO3 as raw materials. The precipitation process as a popular, facile, controllable and cost-effective method was used to produce insoluble inorganic salts. Therefore, it was very important to improve capability and quality of the process for controlling the product Particle size by setting the optimal precipitation reaction parameters. In this research, the parameter design of the Taguchi method was applied to set the optimal parameters of precipitation process for zinc carbonate nano-Particle Preparation. The reaction conditions such as zinc and carbonate ion concentrations, flow rate of reagent addition and reactor temperature were optimized by orthogonal array design, OA9. The effect of these factors on the size of ZnCO3 nanoParticles was quantitatively evaluated by the analysis of variance (ANOVA). The results showed that ZnCO3 nanoParticles can be synthesized via direct carbonation process by controlling zinc and carbonate ion concentrations and flow rate of reagent addition. The experimental results for Preparation of nano-Particles of ZnCO3 showed that the minimum size was about 15 nm and the maximum was about 70 nm. In the next step of this study, an efficient one-step thermal decomposition method was described for Preparation of ZnO nanoParticles from zinc carbonate precursor. The prepared ZnCO3 and ZnO Particles were characterized using X-ray diffraction (XRD), SEM, FT-IR and thermal analysis techniques.