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    Synthesis and swelling behavior of a novel protein-based superabsorbent hydrogel composite: Collagen-g-poly (sodium acrylate)/kaolin

    , Article Journal of Polymer Materials ; Volume 23, Issue 3 , 2006 , Pages 331-339 ; 09738622 (ISSN) Pourjavadi, A ; Feizabadi, Kh ; Hosseinzadeh, H ; Sharif University of Technology
    2006
    Abstract
    This article describes the synthesis and swelling properties of a superabsorbing hydrogel composite based on collagen. The composite have been prepared via graft copolymerization of acrylic acid (AA) in the presence of kaolin powder using methylenebisacrylamide (MBA) as a crosslinking agent and ammonium persulfate (APS) as an initiator. The certain variables of the graft copolymerization (i.e. the monomer, the initiator, and the crosslinker concentration as well as kaolin/collagen weight ratio) affected on the ultimate water-swelling capacity were optimized. Evidence of grafting and kaolin interaction was obtained by comparison of FTIR spectra of initial substrates and superabsorbent... 

    Charactrization of Oxidized Alginate- Gelatin Composite Hydrogel Reinforcement by Ti3C2Tx Mxene for Utilization in Biomedical Applications

    , M.Sc. Thesis Sharif University of Technology Moazeni, Shima (Author) ; Nemati, Ali (Supervisor) ; Mashayekhan, Shohreh (Co-Supervisor)
    Abstract
    Tissue engineering is a science that tries to create new tissues by using cells, growth factors and appropriate biological materials in order to repair damaged organs and replace parts lost due to various reasons. In this research, the effect of adding mxene sheets on the oxidized alginate-gelatin hydrogel scaffold was investigated. For this purpose, mxene nanosheets were first synthesized by Max phase chemical etching and its synthesis was confirmed by X-ray diffraction spectroscoy, field emission scanning electron microscope, X-ray energy diffraction spectroscopy, Fourier-transform infrared spectroscopy, UV-visible spectroscopy. Then, in order to prepare the scaffolds, different amounts of... 

    Synthesis and investigation of swelling behavior of grafted alginate/alumina superabsorbent composite

    , Article Starch/Staerke ; Volume 60, Issue 9 , 9 September , 2008 , Pages 457-466 ; 00389056 (ISSN) Pourjavadi, A ; Farhadpour, B ; Seidi, F ; Sharif University of Technology
    2008
    Abstract
    In this study a novel alginate-g-poly(acrylic acid)/alumina composite was synthesized and characterized. Preparation of the composite hydrogels involved free radical polymerization of a combination of alginate, acrylic acid (AA) and distilled water, in appropriate amounts and N,N-methylene bisacrylamide (MBA) as crosslinking agent. The composite formation was confirmed by Fourier transform infrared spectroscopic (FTIR). The surface morphologies of the synthesized hydrogels were assessed by scanning electron microscopy. Systematically, the different variables of the graft copolymerization were optimized to achieve maximum swelling capacity. The swelling of superabsorbent hydrogels was... 

    Grafted CMC/silica gel superabsorbent composite: Synthesis and investigation of swelling behavior in various media

    , Article Journal of Applied Polymer Science ; Volume 108, Issue 5 , 2008 , Pages 3281-3290 ; 00218995 (ISSN) Pourjavadi, A ; Seidi, F ; Salimi, H ; Soleyman, R ; Sharif University of Technology
    2008
    Abstract
    In the present study, we attempt to synthesize and characterize novel CMC-g-poly (acrylic acid-co-2-acrylamido-2-methylpropanesulfonic acid)/silica gel composite. Infrared spectroscopy and TGA thermal analysis were carried out to confirm the chemical structure of the hydrogel. Moreover, morphology of the samples was examined by scanning electron microscopy. The effect of reaction variables affecting on water absorbency of the composite and swelling behavior in various solvents, salt, and pH solutions was investigated. Maximum water absorbency of the optimized final product was found to be 4000 g/g in distilled water. The absorbency under load (AUL) of the hydrogel was also determined by... 

    PLA microspheres-embedded pva hydrogels prepared by gamma-irradiation and freeze-thaw methods as drug release carriers

    , Article International Journal of Polymeric Materials and Polymeric Biomaterials ; Volume 62, Issue 1 , 2013 , Pages 28-33 ; 00914037 (ISSN) Behnoodfar, D ; Dadbin, S ; Frounchi, M ; Sharif University of Technology
    2013
    Abstract
    A drug delivery system based on poly (vinyl alcohol) (PVA) hydrogels containing ibuprofen-loaded poly (lactic acid) (PLA) microspheres was developed to improve the release kinetics of this model drug. Gamma-irradiation and freeze-thawing were applied to prepare poly (vinyl alcohol) hydrogels. Properties and morphology of these composite hydrogels were investigated using FTIR, DSC, and SEM. In vitro release indicated that entrapment of the microspheres into the PVA hydrogels causes a reduction in both the release rate and the initial burst effect. PLA microspheres entrapped into the PVA hydrogels showed more suitable controlled release kinetics for drug delivery  

    Transport in droplet-hydrogel composites: response to external stimuli

    , Article Colloid and Polymer Science ; Volume 293, Issue 3 , March , 2015 , Pages 941-962 ; 0303402X (ISSN) Mohammadi, A ; Sharif University of Technology
    Springer Verlag  2015
    Abstract
    Determination of effective transport properties of droplet-hydrogel composites is essential for various applications. The transport of ions through a droplet-hydrogel composite subjected to an electric field is theoretically studied as an initial step toward quantifying the effective transport properties of droplet-hydrogel composites. A three-phase electrokinetic model is used to derive the microscale characteristics of the polyelectrolyte hydrogel, and the droplet is considered an incompressible Newtonian fluid. The droplet-hydrogel interface is modeled as a surface, which encloses the interior fluid. The surface has the thickness of zero and the electrostatic potential ζ. Standard... 

    CMC/celite superabsorbent composites: Effect of reaction variables on saline-absorbency under load

    , Article Iranian Polymer Journal (English Edition) ; Volume 19, Issue 8 , May , 2010 , Pages 571-579 ; 10261265 (ISSN) Pourjavadi, A ; Soleyman, R. A ; Ghasemzadeh, H ; Salimi, H ; Sharif University of Technology
    Abstract
    A series of superabsorbent composites were synthesized through graft copolymerization of acrylic acid (AA) onto carboxymethyl cellulose (CMC) in the presence of celite powder using N,N'-methylenebisacrylamide (MBA) as a cross-linking agent and ammonium persulphate (APS) as an initiator. The chemical structure and thermal properties of the composite hydrogels were characterized by FTIR spectroscopy and TGA methods, respectively. Morphology of the samples was examined by scanning electron microscopy (SEM). In free-state, the swelling conditions and hence the related data are not real, because in all their applications the swelling particles of superabsorbent must absorb aqueous solutions while... 

    Customizing nano-chitosan for sustainable drug delivery

    , Article Journal of Controlled Release ; Volume 350 , 2022 , Pages 175-192 ; 01683659 (ISSN) Saeedi, M ; Vahidi, O ; Moghbeli, M ; Ahmadi, S ; Asadnia, M ; Akhavan, O ; Seidi, F ; Rabiee, M ; Saeb, M. R ; Webster, T. J ; Varma, R. S ; Sharifi, E ; Zarrabi, A ; Rabiee, N ; Sharif University of Technology
    Elsevier B.V  2022
    Abstract
    Chitosan is a natural polymer with acceptable biocompatibility, biodegradability, and mechanical stability; hence, it has been widely appraised for drug and gene delivery applications. However, there has been no comprehensive assessment to tailor-make chitosan cross-linkers of various types and functionalities as well as complex chitosan-based semi- and full-interpenetrating networks for drug delivery systems (DDSs). Herein, various fabrication methods developed for chitosan hydrogels are deliberated, including chitosan crosslinking with and without diverse cross-linkers. Tripolyphosphate, genipin and multi-functional aldehydes, carboxylic acids, and epoxides are common cross-linkers used in... 

    Fabrication and characterization of an injectable reinforced composite scaffold for cartilage tissue engineering: An in vitro study

    , Article Biomedical Materials (Bristol) ; Volume 16, Issue 4 , 2021 ; 17486041 (ISSN) Khozaei Ravari, M ; Mashayekhan, S ; Zarei, F ; Sayyahpour, F. A ; Taghiyar, L ; Eslaminejad, M. B ; Sharif University of Technology
    IOP Publishing Ltd  2021
    Abstract
    There are limitations in current medications of articular cartilage injuries. Although injectable bioactive hydrogels are promising options, they have decreased biomechanical performance. Researchers should consider many factors when providing solutions to overcome these challenges. In this study, we created an injectable composite hydrogel from chitosan and human acellular cartilage extracellular matrix (ECM) particles. In order to enhance its mechanical properties, we reinforced this hydrogel with microporous microspheres composed of the same materials as the structural building blocks of the scaffold. Articular cartilage from human donors was decellularized by a combination of physical,...