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alginate
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Partially hydrolyzed crosslinked alginate-graft-polymethacrylamide as a novel biopolymer-based superabsorbent hydrogel having pH-responsive Properties [electronic resource]
, Article Macromolecular Research ; January 2005, Volume 13, Issue 1, pp 45-53 ; Aminfazl, M. S ; Hosseinzadeh, H
Abstract
In this study, a series of highly swelling hydrogels based on sodium alginate (NaAlg) and polymethacrylamide (PMAM) was prepared through free radical polymerization. The graft copolymerization reaction was performed in a homogeneous medium and in the presence of ammonium persulfate (APS) as an initiator andN,N′-methylenebisacrylamide (MBA) as a crosslinker. The crosslinked graft copolymer, alginate-graft-polymethacrylamide (Alg-g-PMAM), was then partially hydrolyzed by NaOH solution to yield a hydrogel, hydrolyzed alginate-graft-polymethacrylamide (H-Alg-g-PMAM). During alkaline hydrolysis, the carboxamide groups of Alg-g-PMAM were converted into hydrophilic carboxylate anions. Either the...
Magnetic/pH-sensitive κ-carrageenan/sodium alginate hydrogel nanocomposite beads: Preparation, swelling behavior, and drug delivery
, Article Journal of Biomaterials Science, Polymer Edition ; Vol. 25, issue. 17 , 2014 , p. 1891-1906 ; Rahmani, Z ; Karami, S ; Pourjavadi, A ; Sharif University of Technology
Abstract
This work describes the preparation of magnetic and pH-sensitive beads based on κ-carrageenan and sodium alginate for use as drug-targeting carriers. Physical cross-linking using K+/Ca2+ ions was applied to obtain ionic cross-linked magnetic hydrogel beads. The produced magnetite beads were thoroughly characterized by TEM, SEM/EDS, XRD, FTIR, and VSM techniques. While the water absorbency (WA) of magnetic beads was enhanced by increasing the weight ratio of κ-carrageenan, introducing magnetic nanoparticles caused a decrease in WA capacity from 15.4 to 6.3 g/g. Investigation on the swelling of the hydrogel beads in NaCl, KCl, and CaCl2 solutions revealed the disintegration of beads depending...
Nanodiamonds for surface engineering of orthopedic implants: Enhanced biocompatibility in human osteosarcoma cell culture
, Article Diamond and Related Materials ; Volume: 40 , 2013 , Pages: 107-114 ; 09259635 (ISSN) ; Shokrgozar, M. A ; Mehrjoo, M ; Tamjid, E ; Simchi, A ; Sharif University of Technology
2013
Abstract
Recently, nanodiamonds have attracted interest in biomedical applications such as drug delivery, targeted cancer therapies, fabrication of tissue scaffolds, and biosensors. We incorporated diamond nanoparticles in alginate-bioactive glass films by electrophoretic process to prepare functional coatings for biomedical implants. Turbidity examination by time-resolved laser transmittance measurement revealed that a stable multi-component aqueous suspension of alginate, bioactive glass and diamond particles could be obtained at concentrations of 0.6, 1.3, and 0.65 g/l, respectively. Uniform films with ~ 5 μm thickness were deposited on 316 stainless steel foils by employing constant field...
Spectrophotometric determination of sulfide based on peroxidase inhibition by detection of purpurogallin formation
, Article Ecotoxicology and Environmental Safety ; Volume 91 , 2013 , Pages 117-121 ; 01476513 (ISSN) ; Kariminia, H. R ; Roosta Azad, R ; Sharif University of Technology
2013
Abstract
This paper presents a new method for spectrophotometirc detection of sulfide applying fungal peroxidase immobilized on sodium alginate. The sensing scheme was based on decrease of the absorbance of the orange compound, purpurogallin produced from pyrogallol and H2O2 as substrates, due to the inhibition of peroxidase by sulfide. Absorbance of purpurogallin was detected at 420nm by using a spectrophotometer. The proposed method could successfully detect the sulfide in the concentration range of 0.6-7.0μM with a detection limit of 0.4μM. The kinetic parameters of Michaelis-Menten with and without sulfide were also calculated. Possible inhibition mechanism of peroxidase by sulfide was deduced...
A superabsorbent hydrogel network based on poly ((2-dimethylaminoethyl) methacrylate) and sodium alginate obtained by γ-radiation: Synthesis and characterization
, Article Iranian Polymer Journal (English Edition) ; Volume 21, Issue 12 , 2012 , Pages 829-836 ; 10261265 (ISSN) ; Hooshyar, Z ; Zehtabi, F ; Pourjavadi, A ; Sharif University of Technology
2012
Abstract
In this study, the synthesis and characterization of a novel nano-porous superabsorbent hydrogel with high water swelling capacity is described. A nano-porous hydrogel was prepared by employing (2-dimethylaminoethyl) methacrylate (PDMAEMA) as a pH sensitive monomer and sodium alginate (SA) as a water soluble polysaccharide under γ-ray irradiation. The polymerization reaction was performed at room temperature in the absence of chemically toxic crosslinking agent and initiators. The interactive parameters including biopolymer backbone concentration, monomer concentration and γ-irradiation dose were selected as major factors in the synthesis of superabsorbent and three levels for each factor...
Fabrication of granulated NaY zeolite nanoparticles using a new method and study the adsorption properties
, Article Powder Technology ; Volume 231 , November , 2012 , Pages 1-6 ; 00325910 (ISSN) ; Kazemeini, M ; Ahmadi, S. J ; Kazemian, H ; Sharif University of Technology
2012
Abstract
NaY zeolite nanoparticles were synthesized and shaped into the uniform spherical granules using a developed novel and simple two-step granulation technique. First, the alginate/nanozeolite or alginate/nanozeolite-bentonite spherical hybrid was successfully fabricated, and then the alginate was decomposed by calcinations resulting uniform spherical granules. To improve the mechanical stability of the prepared granules, bentonite was added as an inorganic binder at different ratios of 20wt.% to 40wt.%. Moreover, the effect of binder on the ion exchange properties of the prepared granules was studied. Increasing of binder content from 20wt.% to 40wt.% linearly enhanced the mechanical stability...
Adsorption behavior of toxic metal Ions on nano-structured CuO granules
, Article Separation Science and Technology (Philadelphia) ; Volume 47, Issue 7 , 2012 , Pages 1063-1069 ; 01496395 (ISSN) ; Sadjadi, S ; Hosseinpour, M ; Sharif University of Technology
2012
Abstract
In this study, copper oxide nano particles were synthesized by batchwise supercritical hydrothermal method. After preparation of CuO nano particles, they were immobilized into the porous matrix of sodium alginate. The drying process formed a very porous structure that is useful for enhancing of adsorption activity. Produced CuO particles were characterized by X-ray diffractometery (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), and BET for measuring the surface area. The prepared materials were then used as adsorbent in the removal of toxic metal ions in aqueous solution. To optimize the adsorption system, the effect of various parameters such as adsorbent...
A simple granulation technique for preparing high-porosity nano copper oxide(II) catalyst beads
, Article Particuology ; Volume 9, Issue 5 , 2011 , Pages 480-485 ; 16742001 (ISSN) ; Outokesh, M ; Hosseinpour, M ; Mousavand, T ; Sharif University of Technology
Abstract
A simple and efficient method was developed for fabricating spherical granules of CuO catalyst via a three-step procedure. In the first step, copper oxide nanoparticles were synthesized by hydrothermal decomposition of copper nitrate solution under supercritical condition. Then, they were immobilized in the polymeric matrix of calcium alginate, and followed by high-temperature calcination in an air stream as the third step, in which carbonaceous materials were oxidized, to result in a pebble-type catalyst of high porosity. The produced CuO nanoparticles were characterized by transmission electron microscopy (TEM) that revealed an average size of 5 nm, X-ray diffractometry (XRD), and thermo...
Granulated copper oxide nano-catalyst: A novel and efficient catalyst for C-N cross-coupling of amines with iodobenzene
, Article Monatshefte fur Chemie ; Volume 142, Issue 8 , 2011 , Pages 801-806 ; 00269247 (ISSN) ; Sadjadi, S ; Hosseinpour, M ; Abdollahi, M ; Sharif University of Technology
Abstract
Nano-structured CuO granules catalyze the C-N cross-coupling of amines with iodobenzene in excellent yields. The reaction is simple, efficient, and operates in air under ligand-free conditions
Synthesis and characterization of new biopolymeric microcapsules containing DEHPA-TOPO extractants for separation of uranium from phosphoric acid solutions
, Article Journal of Microencapsulation ; Volume 28, Issue 4 , 2011 , Pages 248-257 ; 02652048 (ISSN) ; Tayyebi, A ; Khanchi, A ; Grayeli, F ; Bagheri, G ; Sharif University of Technology
Abstract
A novel microcapsule adsorbent for separation of uranium from phosphoric acid solutions was developed by immobilizing the di(2-ethylhexyl) phosphoric acid-trioctyl phosphine oxide extractants in the polymeric matrix of calcium alginate. Physical characterization of the microcapsules was accomplished by scanning electron microscopy and thermogravimetric techniques. Equilibrium experiments revealed that both ion exchange and solvent extraction mechanisms were involved in the adsorption of ions, but the latter prevailed in a wider range of acid concentration. According to the results of kinetics study, at low acidity level, the rate controlling step was slow chemical reaction of ions with the...
Electrophoretic Deposition of Alginate-Bioglass-Nanodiamond Nanocomposites and Evolution of their Bioactivity
, M.Sc. Thesis Sharif University of Technology ; Simchi, Abdollreza (Supervisor)
Abstract
Recently, diamond nanoparticles have attracted interest for biomedical applications such as drug delivery, targeted cancer therapies, fabrication of tissue scaffolds and biosensors. In the present work, elecrophoretic deposition (EPD) of nanodiamond-bioactive glass-alginate nanocomposite was studied. In vitro bioactivity and biocompatibility of the nanocomposite were evaluated in simulated body fluid (SBF) and by MTT assay. The EPD process was performed under different conditions in order to obtain a uniform coating on the surface of 316L stainless steel substrate. The stability of the suspension was determined via optical sedimentation method and zeta potential analysis. It was found that...
Human Cells Separation Via Imprinted Polymer
, M.Sc. Thesis Sharif University of Technology ; Abdekhodaie, Mohammad Jafar (Supervisor)
Abstract
The goal of this research is to elucidate the mechanism of Cell recognition in molecularly imprinted polymers (MIPs) using already utilized techniques. Our approach employs a more flexible non-covalent imprinting method which starts from a readily available polymer and utilizes an aqueous environment for both MIP synthesis and testing. Cell MIPs against MG-63 cell were synthesized. The synthesis procedure was optimized to obtain better binding characteristics to the targeted cell. Adsorption of target cell onto imprinted Alginate Spheres was facilitated by these macromolecular fingerprints as revealed by various microscopical examinations The imprinted Spheres showed high selectivity toward...
Study and Synthesis of Biocompatible Polymer and Loading of Peptide Drug for using in Drug Delivery
, M.Sc. Thesis Sharif University of Technology ; Vosoughi, Manouchehr (Supervisor) ; Alemzadeh, Iran (Co-Advisor)
Abstract
With the rapid development of biotechnology, peptide and protein drugs are now playing an increasingly important role in therapeutics. Compared with chemical drugs, peptide and protein drugs have some limitations such as low stability and rapid deactivation. Biodegradable and biocompatible polymeric micro carriers have been shown to have a high potential for the delivery of peptides and proteins. Among these polymers, alginate has been widely investigated as a biomaterial. Alginates are natural polysaccharide polymers isolated from brown seaweed. Bovine serum albumin (BSA) loaded calcium alginate microspheres produced in this study by a modified w/o emulsification method. The influence of...
Preparation of Gelatin-Alginate Hydrogel for Using as Cell Culture Scaffold
, M.Sc. Thesis Sharif University of Technology ; Mashayekhan, Shohreh (Supervisor) ; Maghsoudi, Vida (Supervisor)
Abstract
Hydrogels are polymeric three-dimensional networks able to swell in the presence of an aqueous medium. Hydrogels from natural proteins and polysaccharides are ideal scaffolds for tissue engineering since they resemble the extracellular matrices of tissue comprised of various amino acids and sugar-based macromolecules.The biocompatible and biodegradable hydrogel scaffolds are promising materials for tissue engineering. Here, we report a new class of hydrogels derived from oxidized alginate (OA) and gelatin. The prepared oxidized alginate was shown to be efficient in crosslinking gelatin, leading to hydrogel formation. The effect of degree of oxidation and concentration of OA on the mechanical...
Antibacterial silver nanoparticles in polyvinyl alcohol/sodium alginate blend produced by gamma irradiation
, Article International Journal of Biological Macromolecules ; Volume 80 , 2015 , Pages 170-176 ; 01418130 (ISSN) ; Frounchi, M ; Dadbin, S ; Sharif University of Technology
Abstract
Polyvinyl alcohol/sodium alginate/nano silver (PVA/SA/Ag) composite films were made by solution casting method. Gamma irradiation was used to synthesize silver nanoparticles in situ via reduction of silver nitrate without using harmful chemical agents for biomedical applications. UV-vis and XRD results demonstrated that spherical silver nanoparticles were produced even at low irradiation dose of 5. kGy. By increasing irradiation dose, more nanoparticles were synthesized while no PVA hydrogel was formed up to 15. kGy. Also the size of nanoparticles was reduced with increasing gamma dose evidenced by higher release rate of silver nanoparticles in lukewarm water and SEM images. Comparing SEM...
Magnetic graphene oxide mesoporous silica hybrid nanoparticles with dendritic pH sensitive moieties coated by PEGylated alginate-co-poly (acrylic acid) for targeted and controlled drug delivery purposes
, Article Journal of Polymer Research ; Volume 22, Issue 8 , 2015 ; 10229760 (ISSN) ; Shakerpoor, A ; Tehrani, Z. M ; Bumajdad, A ; Sharif University of Technology
Kluwer Academic Publishers
2015
Abstract
In this study synthesis of a drug delivery system (DDS) is described which has several merits over its counterparts. In order to synthesize this nano-carrier, graphene oxide nano-sheets are used to accommodate MCM-41 nanoparticles. Furthermore Fe3 O4 nanoparticles are introduced to this nano-material to produce a traceable nanoparticle. Since cancerous tissues have lower pH than healthy tissues, pH-sensitive oligomers are attached to this nano-material. Finally the nano-carrier is wrapped by a biocompatible shell (PEGylated sodium alginate); this polymeric shell makes the DDS capable of a more controllable drug release. By measuring in vitro situation, ‘loading content%’...
Investigating the effect of design parameters on the response time of a highly sensitive microbial hydrogen sulfide biosensor based on oxygen consumption
, Article Biosensors and Bioelectronics ; Volume 70 , 2015 , Pages 106-114 ; 09565663 (ISSN) ; Yazdian, F ; Amoabediny, G ; Hakim, M ; Sharif University of Technology
Elsevier Ltd
2015
Abstract
A novel hydrogen sulfide microbial biosensor was developed based on investigating the influence of four design parameters: cell concentration, immobilization bed type, hydrogen sulfide concentration, and geometrical shape of the biosensor. Thiobacillus thioparus was used as the recognition element and it was immobilized on sodium alginate as well as agarose bed. The results were optimized by the application of statistical optimization software based on response time of the system. Oxygen reduction was considered as the detection sign. Sodium alginate solution with a concentration of 2.3% (w/v) and optical density of 10 at 605. nm was found as the optimum conditions for immobilization with...
Alginate-based biodegradable superabsorbents as candidates for diclofenac sodium delivery systems
, Article Journal of Applied Polymer Science ; Volume 118, Issue 4 , 2010 , Pages 2015-2023 ; 00218995 (ISSN) ; Zeidabadi, F ; Barzegar, Sh ; Sharif University of Technology
2010
Abstract
Novel types of highly swelling hydrogels were prepared by grafting crosslinked polyacrylamide-co-poly-2-acrylamido-2-methylpropane sulfonic acid (PAAm-co-PAMPS) chains onto sodium alginate (Na-Alg) through a free radical polymerization method. The superabsorbent formation was confirmed by Fourier transform infrared spectroscopic (FTIR). The controlled release behavior of diclofenac sodium (DS) from superabsorbent polymer was factinvestigated, and shown that the release profiles of DS from superabsorbent polymer were slow in simulated gastric fluid (SGF, pH 1.2) over 3 h, but nearly all of the initial drug content was released in simulated intestinal fluid (SIF, pH 7.4) within 21 h after...
Synthesis of Double Network Hydrogels Based on Chitosan, Alginate, and Poly (Vinyl Alchohol) with High Mechanical Properties and Investigation of Their Biocompatibility
, M.Sc. Thesis Sharif University of Technology ; Pourjavadi, Ali (Supervisor)
Abstract
Double network (DN) hydrogels are a new interpenetrate polymer network (IPN) that are usually contain about 60-90 % water. Despite of this amount of water, they are though and strong. DN hydrogels comprise of two networks, the first one as the brittle gel, is generally high density crosslinked and the second one, the loose and stretchable network, is loosely crosslinked or even without crosslinking. Therefore, we used cationic polymer, chitosan, and anionic polymer, alginate, as the first networks, therefore, we used sodium phosphate for physical crosslinking of chitosan, and calcium chloride as the physical crosslinking agents for alginate network. Also, poly (vinyl alcohol) (PVA), as the...
Synthesis and characterization of a bentonite-alginate microspherical adsorbent for removal of uranyl ions from aqueous Solutions
, Article Separation Science and Technology ; Volume 45, Issue 2 , 2010 , Pages 288-298 ; 01496395 (ISSN) ; Khanchi, A ; Ghofrani, M.B ; Outokesh, M ; Sharif University of Technogy
2010
Abstract
A novel microspherical adsorbent for the removal of uranium from aqueous solutions was developed by immobilizing of natural bentonite in the polymeric matrix of calcium alginate. Different uptake properties of the prepared microspheres were examined using batch, stirred and column methods. The adsorbent showed high affinity toward uranium ions, especially at pHs above 3. Major uptake mechanisms included ion exchange, chelating of the (UO2)2+ ions to the -OH groups of alginate, and surface complexation with bentonite. Surprisingly, the capacity of microspheres was higher than both its constituents, revealing that a synergetic effect occurs. Adsorption kinetics was controlled by slow chemical...