Search for: alginic-acid
0.005 seconds

    Partially hydrolyzed crosslinked alginate-graff-polymethacrylamide as a novel biopolymer-based superabsorbent hydrogel having pH-responsive properties

    , Article Macromolecular Research ; Volume 13, Issue 1 , 2005 , Pages 45-53 ; 15985032 (ISSN) Pourjavadi, A ; Amini Fazl, M. S ; Hosseinzadeh, H ; Sharif University of Technology
    Polymer Society of Korea  2005
    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 and N,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... 

    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) Ghadiri, M ; Kariminia, H. R ; Roosta Azad, R ; Sharif University of Technology
    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... 

    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) Charkhi, A ; Kazemeini, M ; Ahmadi, S. J ; Kazemian, H ; Sharif University of Technology
    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... 

    Drug delivery systems and materials for wound healing applications

    , Article Advanced Drug Delivery Reviews ; Volume 127 , 2018 , Pages 138-166 ; 0169409X (ISSN) Saghazadeh, S ; Rinoldi, C ; Schot, M ; Saheb Kashaf, S ; Sharifi, F ; Jalilian, E ; Nuutila, K ; Giatsidis, G ; Mostafalu, P ; Derakhshandeh, H ; Yue, K ; Swieszkowski, W ; Memic, A ; Tamayol, A ; Khademhosseini, A ; Sharif University of Technology
    Elsevier B.V  2018
    Chronic, non-healing wounds place a significant burden on patients and healthcare systems, resulting in impaired mobility, limb amputation, or even death. Chronic wounds result from a disruption in the highly orchestrated cascade of events involved in wound closure. Significant advances in our understanding of the pathophysiology of chronic wounds have resulted in the development of drugs designed to target different aspects of the impaired processes. However, the hostility of the wound environment rich in degradative enzymes and its elevated pH, combined with differences in the time scales of different physiological processes involved in tissue regeneration require the use of effective drug... 

    Double network hydrogel of sodium alginate/polyacrylamide cross-linked with POSS: Swelling, dye removal and mechanical properties

    , Article International Journal of Biological Macromolecules ; Volume 129 , 2019 , Pages 187-197 ; 01418130 (ISSN) Bahrami, Z ; Akbari, A ; Eftekhari Sis, B ; Sharif University of Technology
    Elsevier B.V  2019
    In this work, for the first time, we presented a novel design strategy to fabricate a new type of Octa-aminopropyl polyhedral oligomeric silsesquioxane hydrochloride salt (OA-POSS)-based Alg/PAAm DN gels, consisting of PAAm gel as the first chemical network and Alg/OA-POSS gel as the second chemical-physical network. Incorporation of OA-POSS nanoparticles with various feed ratio into the second network not only led to form strong coordination interactions but also in comparison to the other Alg/PAAm gels demonstrated superior mechanical properties. pH, temperature, contact time and salt effects parameters were studied on the swelling and dye removal properties of the synthesized DN hybrid... 

    Biodegradable nanopolymers in cardiac tissue engineering: from concept towards nanomedicine

    , Article International Journal of Nanomedicine ; Volume 15 , 2020 , Pages 4205-4224 Mohammadi Nasr, S ; Rabiee, N ; Hajebi, S ; Ahmadi, S ; Fatahi, Y ; Hosseini, M ; Bagherzadeh, M ; Ghadiri, A. M ; Rabiee, M ; Jajarmi, V ; Webster, T. J ; Sharif University of Technology
    Dove Medical Press Ltd  2020
    Cardiovascular diseases are the number one cause of heart failure and death in the world, and the transplantation of the heart is an effective and viable choice for treatment despite presenting many disadvantages (most notably, transplant heart availability). To overcome this problem, cardiac tissue engineering is considered a promising approach by using implantable artificial blood vessels, injectable gels, and cardiac patches (to name a few) made from biodegradable polymers. Biodegradable polymers are classified into two main categories: natural and synthetic polymers. Natural biodegradable polymers have some distinct advantages such as biodegradability, abundant availability, and... 

    Injectable hydrogels based on oxidized alginate-gelatin reinforced by carbon nitride quantum dots for tissue engineering

    , Article International Journal of Pharmaceutics ; Volume 602 , 2021 ; 03785173 (ISSN) Ghanbari, M ; Salavati Niasari, M ; Mohandes, F ; Sharif University of Technology
    Elsevier B.V  2021
    Stem cell treatment is promising in the various disorders treatment, but its effect is confined by the adverse conditions in the damaged tissues. The utilization of hydrogels has been suggested as a procedure to defeat this issue by developing the engraftment and survival of injected stem cells. Specifically, injectable hydrogels have drawn much attention due to their shape adaptability, ease of use, and the capability to reach body parts that are hard to access. In this study, the thermosensitive injectable hydrogels based on oxidized alginate, gelatin, and carbon nitride quantum dots (CNQDs) have been fabricated for tissue engineering. The mechanical characteristics of the nanocomposite... 

    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 Mahdavinia, G. R ; Rahmani, Z ; Karami, S ; Pourjavadi, A ; Sharif University of Technology
    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... 

    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) Vosoughi, A ; Yazdian, F ; Amoabediny, G ; Hakim, M ; Sharif University of Technology
    Elsevier Ltd  2015
    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... 

    Phenols removal by immobilized horseradish peroxidase

    , Article Journal of Hazardous Materials ; Volume 166, Issue 2-3 , 2009 , Pages 1082-1086 ; 03043894 (ISSN) Alemzadeh, I ; Nejati, S ; Sharif University of Technology
    Application of immobilized horseradish peroxidase (HRP) in porous calcium alginate (ca-alginate) for the purpose of phenol removal is reported. The optimal conditions for immobilization of HRP in ca-alginate were identified. Gelation (encapsulation) was optimized at 1.0% (w/v) sodium alginate in the presence of 5.5% (w/v) of calcium chloride. Upon immobilization, pH profile of enzyme activity changes as it shows higher value at basic and acidic solution. Increasing initial phenol concentration results in a decrease in % conversion. The highest conversion belongs to phenol concentration of 2 mM. Investigation into time course of phenol removal for both encapsulated and free enzymes showed... 

    Optimization of alginate-whey protein isolate microcapsules for survivability and release behavior of probiotic bacteria

    , Article Applied Biochemistry and Biotechnology ; Volume 190, Issue 1 , 2020 , Pages 182-196 Sajadi Dehkordi, S ; Alemzadeh, I ; Vaziri, A. S ; Vossoughi, A ; Sharif University of Technology
    Springer  2020
    The present study aimed to improve the survivability of L. acidophilus encapsulated in alginate-whey protein isolate (AL-WPI) biocomposite under simulated gastric juice (SGJ) and simulated intestinal juice (SIJ). Microcapsules were prepared based on emulsification/internal gelation technique. Optimal compositions of AL and WPI and their ratio in the aqueous phase were evaluated based on minimizing mean diameter (MD) of the microcapsules and maximizing encapsulation efficiency (EE), survivability of cells under SGJ (Viability), and release of viable cells under SIJ (Release) using Box-Behnken experimental design. Optimal composition comprising 4.54% (w/v) AL, 10% (w/v) WPI, and 10% (v/v)... 

    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) Eghbalifam, N ; Frounchi, M ; Dadbin, S ; Sharif University of Technology
    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... 

    Synthesis of a novel magnetic starch-alginic acid-based biomaterial for drug delivery

    , Article Carbohydrate Research ; Volume 487 , 2020 Forouzandehdel, S ; Forouzandehdel, S ; Rezghi Rami, M ; Sharif University of Technology
    Elsevier Ltd  2020
    The magnetic composite hydrogel was fabricated by the graft copolymerization of itaconic acid (IA) onto starch and Alginic acid in the presence graphene sheets (Gr) and Fe3O4 nanoparticles (Fe3O4@Gr-IA/St-Alg) for Guaifenesin (GFN) delivery and wound healing. The Fe3O4@Gr-IA/St-Alg biomaterial is a hydrogel network endowed the material with magnetic property. In addition, GFN not only achieved effectively bound to the magnetic hydrogel, but also released in a controlled manner. The using external magnetic field has significantly positive influence on the drug release rate. To close, these hydrogel drug carriers offer a favorable platform for magnetically targeted drug delivery as well as a... 

    Folate conjugated hyaluronic acid coated alginate nanogels encapsulated oxaliplatin enhance antitumor and apoptosis efficacy on colorectal cancer cells (HT29 cell line)

    , Article Toxicology in Vitro ; Volume 65 , 2020 Movahedi Shad, P ; Zare Karizi, S ; Safaie Javan, R ; Mirzaie, A ; Noorbazargan, H ; Akbarzadeh, I ; Rezaie, H ; Sharif University of Technology
    Elsevier Ltd  2020
    Oxaliplatin (OXA) has been widely used for treatment of colorectal cancer. In this study, to enhance antitumor and apoptosis efficacy, OXA was encapsulated in a novel folate conjugated hyaluronic acid coated alginate nanogels (F/HA/AL/OXA). The F/HA/AL/OXA nanogels were prepared by cross-linking process. The physico-chemical properties of F/HA/AL/OXA nanogels were characterized using scanning electron microscopy, transmission electron microscopy, fourier transform infrared spectroscopy, dynamic light scattering, and fluorescent spectrophotometry. The in-vitro antitumor activity of free OXA, AL, HA/AL, HA/AL/OXA and F/HA/AL/OXA nanogels were assessed using MTT assay against colorectal cancer... 

    Biohybrid oxidized alginate/myocardial extracellular matrix injectable hydrogels with improved electromechanical properties for cardiac tissue engineering

    , Article International Journal of Biological Macromolecules ; Volume 180 , 2021 , Pages 692-708 ; 01418130 (ISSN) Mousavi, A ; Mashayekhan, S ; Baheiraei, N ; Pourjavadi, A ; Sharif University of Technology
    Elsevier B.V  2021
    Injectable hydrogels which mimic the physicochemical and electromechanical properties of cardiac tissue is advantageous for cardiac tissue engineering. Here, a newly-developed in situ forming double-network hydrogel derived from biological macromolecules (oxidized alginate (OA) and myocardial extracellular matrix (ECM)) with improved mechanical properties and electrical conductivity was optimized. 3-(2-aminoethyl amino) propyltrimethoxysilane (APTMS)-functionalized reduced graphene oxide (Amine-rGO) was added to this system with varied concentrations to promote electromechanical properties of the hydrogel. Alginate was partially oxidized with an oxidation degree of 5% and the resulting OA... 

    Nanomedicine and advanced technologies for burns: Preventing infection and facilitating wound healing

    , Article Advanced Drug Delivery Reviews ; Volume 123 , 2018 , Pages 33-64 ; 0169409X (ISSN) Mofazzal Jahromi, M. A ; Sahandi Zangabad, P ; Moosavi Basri, S. M ; Sahandi Zangabad, K ; Ghamarypour, A ; Aref, A. R ; Karimi, M ; Hamblin, M. R ; Sharif University of Technology
    Elsevier B.V  2018
    According to the latest report from the World Health Organization, an estimated 265,000 deaths still occur every year as a direct result of burn injuries. A widespread range of these deaths induced by burn wound happens in low- and middle-income countries, where survivors face a lifetime of morbidity. Most of the deaths occur due to infections when a high percentage of the external regions of the body area is affected. Microbial nutrient availability, skin barrier disruption, and vascular supply destruction in burn injuries as well as systemic immunosuppression are important parameters that cause burns to be susceptible to infections. Topical antimicrobials and dressings are generally... 

    Zn-rich (GaN)1−x(ZnO)x: a biomedical friend?

    , Article New Journal of Chemistry ; Volume 45, Issue 8 , 2021 , Pages 4077-4089 ; 11440546 (ISSN) Bagherzadeh, M ; Rabiee, N ; Fatahi, Y ; Dinarvand, R ; Sharif University of Technology
    Royal Society of Chemistry  2021
    A Zn-Rich (GaN)1−x(ZnO)xnanostructure was synthesized with the assistance of a high-gravity technique in order to reduce the reaction time and temperature. The synthesized inorganic nanomaterial has been applied in both drug and gene delivery systems, and as the first fully inorganic nanomaterial, it was investigated in a comprehensive cellular investigation as well. In order to increase the potential bioavailability, as well as the interactions with the pCRISPR, the nanomaterial was enriched with additional Zn ions. The nanomaterial and the final nanocarrier were characterized at each step before and after any biological analysisviaFESEM, AFM, TEM, FTIR and XRD. The polymer coated... 

    Silica nanoparticle surface chemistry: An important trait affecting cellular biocompatibility in two and three dimensional culture systems

    , Article Colloids and Surfaces B: Biointerfaces ; Volume 182 , 2019 ; 09277765 (ISSN) Hasany, M ; Taebnia, N ; Yaghmaei, S ; Shahbazi, M. A ; Mehrali, M ; Dolatshahi Pirouz, A ; Arpanaei, A ; Sharif University of Technology
    Elsevier B.V  2019
    Great advantages bestowed by mesoporous silica nanoparticles (MSNs) including high surface area, tailorable pore diameter and surface chemistry, and large pore volume render them as efficient tools in biomedical applications. Herein, MSNs with different surface chemistries were synthesized and investigated in terms of biocompatibility and their impact on the morphology of bone marrow-derived mesenchymal stem cells both in 2D and 3D culture systems. Bare MSNs (BMSNs) were synthesized by template removing method using tetraethylorthosilicate (TEOS) as a precursor. The as-prepared BMSNs were then used to prepare amine-functionalized (AMSNs), carboxyl-functionalized (CMSNs) and polymeric...