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hydrogels
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Partially hydrolyzed kappa carrageenan - polyacrylonitrile as a novel biopolymer-based superabsorbent hydrogel: synthesis, characterization, and swelling behaviors
, Article Polymer Engineering and Science ; Volume 46, Issue 12 , 2006 , Pages 1778-1786 ; 00323888 (ISSN) ; Pourjavadi, A ; Sharif University of Technology
2006
Abstract
In this paper, synthesis and swelling behavior of a novel superabsorbent hydrogel based on kappa carrageenan (κC) and polyacrylonitrile (PAN) was investigated. To achieve partially hydrolyzed κC-PAN hydrogel, physical mixture of κC and PAN was hydrolyzed by NaOH solution. During alkaline hydrolysis, the nitrile groups of PAN are converted to a mixture of hydrophilic carboxamide and carboxylate groups follow by in situ crosslinking of the grafted PAN chains. The reaction variables affecting on the swelling capacity of the hydrogel were systematically optimized to achieve a hydrogel with swelling capacity as high as possible. Under the optimized conditions concluded, super swelling hydrogel...
Removal of Cu (ll) from industrial wastewater using poly (acrylamide-co-2-acrylamide-2-methyl propane sulfonic acid)/graphene oxide/sodium alginate hydrogel: Isotherm, kinetics, and optimization study
, Article Journal of Water Process Engineering ; Volume 42 , 2021 ; 22147144 (ISSN) ; Ghasemi, S ; Khosravi, A ; ZabihiSahebi, A ; Hasan Zadeh, A ; Borghei, S. M ; Sharif University of Technology
Elsevier Ltd
2021
Abstract
Here, Graphene oxide/poly (acrylamide -2-acrylamide-methyl-propanesulfonic acid)/sodium alginate (GO/PA-AMPS/SA) hydrogel was synthesized through a free-radical polymerization approach. The impact of Graphene Oxide (GO) content on mechanical strength, swelling behavior, and the adsorption performance of prepared hydrogel was studied. The operating parameters, including contact time, solution pH, and initial Cu(II) content on the adsorption capacity of the hydrogel, were studied. The maximum Cu(II) adsorption capacity of 230.8 mg/g was obtained for GO/PA-AMPS/SA under a pH of 5, the contact time of 270 min, and adsorbent content of 0.5 g/L at 25 °C. The high value of adsorption capacity after...
An electroconductive, thermosensitive, and injectable chitosan/pluronic/gold-decorated cellulose nanofiber hydrogel as an efficient carrier for regeneration of cardiac tissue
, Article Materials ; Volume 15, Issue 15 , 2022 ; 19961944 (ISSN) ; Maleki Jirsaraei, N ; Simchi, A ; Mohandes, F ; Emami, Z ; Fassina, L ; Naro, F ; Conti, B ; Barbagallo, F ; Sharif University of Technology
MDPI
2022
Abstract
Myocardial infarction is a major cause of death worldwide and remains a social and healthcare burden. Injectable hydrogels with the ability to locally deliver drugs or cells to the damaged area can revolutionize the treatment of heart diseases. Herein, we formulate a thermo-responsive and injectable hydrogel based on conjugated chitosan/poloxamers for cardiac repair. To tailor the mechanical properties and electrical signal transmission, gold nanoparticles (AuNPs) with an average diameter of 50 nm were physically bonded to oxidized bacterial nanocellulose fibers (OBC) and added to the thermosensitive hydrogel at the ratio of 1% w/v. The prepared hydrogels have a porous structure with open...
Piezoelectric behavior of Gamma-radiated nanocomposite hydrogel based on PVP-PEG-BaTiO3
, Article Materials Science and Engineering B: Solid-State Materials for Advanced Technology ; Volume 276 , 2022 ; 09215107 (ISSN) ; Frounchi, M ; Dadbin, S ; Sharif University of Technology
Elsevier Ltd
2022
Abstract
This study aimed to evaluate the properties of nanocomposite hydrogel (NCH) based on poly (vinyl pyrrolidone) (PVP), poly (ethylene glycol) (PEG), and Barium titanate (BTNPs). Gamma radiation at various doses (25 kGy, 35 kGy) was employed to prepare cross-linked hydrogel. The effect of PVP concentration, PVP/PEG ratio, and BTNPs content, and irradiation dosage on gel content and swelling ratio of synthesized hydrogels were determined. The Flory-Rehner equation was employed to calculate the network parameters. The FTIR results indicate that the chemical structure was deformed through crosslinking PVP macromolecule radicals. The XRD spectra indicated the cubic phase of BTNPs particles and the...
Customizing nano-chitosan for sustainable drug delivery
, Article Journal of Controlled Release ; Volume 350 , 2022 , Pages 175-192 ; 01683659 (ISSN) ; 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 of Composite Scaffold Composed of Cartilage Extracellular Matrix/Chitosan with High Mechanical Strength for Cartilage Tissue Engineering
, M.Sc. Thesis Sharif University of Technology ; Mashayekhan, Shohreh (Supervisor) ; Baghban Eslami Nejad, Mohammad Reza (Supervisor)
Abstract
Methods that has been used for articular defects are faced with many limitations, so new therapies based on tissue engineering were taken into consideration in recent years. However, tissue engineering also encounters challenges regarding optimal scaffold construction and suitable cell source selection. Mature harvested chondrocytes are limited in number and may lose their chondrogenic potential in several cultures, leading to dedifferentiation. In addition, using stem cells also presents unique challenges associated with them, among which hypertrophic differentiation is the most substantial problem. Choosing the appropriate biomaterial similar to the cartilage structure with sufficient...
Development of an Optimized Skin Scaffold Capable of Growth Factor Release for Acute Skin Wound Healing
, M.Sc. Thesis Sharif University of Technology ; Shamloo, Amir (Supervisor) ; Firoozbakhsh, Keykhosrow (Supervisor)
Abstract
As the first barrier in front of external damages, skin is prone to the largest number of damages applied to one’s body. Acute wounds are considerably prevalent world-widely, imposing very high costs to governments. The purpose of the current project, is to propose a novel skin scaffold capable of growth factor delivery for enhancing the wound healing process in acute wounds. Such a scaffold should be able to decrease the required time for healing process, also to improve the quality of the regenerated skin compared to available commercial products. Furthermore, it should be highly biocompatible, biodegradable, and non-toxic. In this project, to manufacture the artificial skin scaffold, a...
Synthesis and in Vitro/in Vivo Evaluation of Bioprinted and Core-Shell Systems Containing Proteoglycan Nanoparticle and Growth Factor for Skin Tissue Regeneration
, Ph.D. Dissertation Sharif University of Technology ; Simchi, Abdolreza (Supervisor) ; Shokrgozar, Mohammad Ali (Supervisor) ; Tamjid, Elnaz (Co-Supervisor)
Abstract
Tissue engineering has the potential to revolutionize our health care system. Conceptually, lost or malfunctioning tissues will be replaced by man-made biological substitutes to restore, maintain, or improve function. Tissue engineering has already shown great promise to contribute to treatments of a myriad of diseases including osteoarthritis, cancer, diabetes, skin burns, cardiovascular conditions and various traumatic injuries. Tissue engineering is a highly multidisciplinary discipline that demands integration of knowledge, tools and skills from biology, chemistry, engineering and medicine. Integrating nano- and microtechnologies into clinically sized implants represents a major...
PVP-PEG-BaTiO3 Hydrogels, Synthesis and Characterization for Medical Applications
, M.Sc. Thesis Sharif University of Technology ; Frounchi, Masoud (Supervisor) ; Dadbin, Susan (Supervisor)
Abstract
Today, hydrogels have various biomedical applications as three-dimensional networks with the ability to absorb and retain water and biological fluids. This study aimed to prepare nanocomposite hydrogels from polyvinyl pyrrolidone, polyethylene glycol, and barium titanate nanoparticles. Gamma radiation at irradiation doses of 25 and 35 kGy was used as the hydrogel's crosslinking agent. The effects of gamma irradiation dose, percentage of polyethylene glycol, and barium titanate composition on the swelling ratio and gel content were investigated. It was observed that the amount of gel content with the addition of polyethylene glycol and barium titanate nanoparticles reduces the gel content and...
Design and Synthesis of Self-healing Gels Based on Natural Polysaccharides Using Reversible Bonds and Investigations of their Applications
, Ph.D. Dissertation Sharif University of Technology ; Pourjavadi, Ali (Supervisor)
Abstract
In recent years, burns and deep wounds that occur in various accidents are important reasons of death in the world. Therefore, the healing process of burn and full thickness of wounds due to late treatment has always been considered by physicians. Thus, the correct treatment and speed of healing of these types of wounds have always been studied. Many synthetic and natural materials have been used to treat wounds, which among them, hydrogels have received a great attention due to creating a moist environment for wounds and absorbing secretions. However, external mechanical stresses may degrade the therapeutic hydrogel. Recently, self-healing coating hydrogels have been designed and developed...
Optimization of Insulin Releasing from Hydrogel Encapsulated Beta Cells
, M.Sc. Thesis Sharif University of Technology ; Alemzadeh, Iran (Supervisor) ; Vosoughi, Manouchehr (Co-Supervisor)
Abstract
Beta cells are responsible for secreting insulin to maintain normoglycaemia throughout the individual’s life. Type 1 Diabetes Mellitus (T1DM) is a metabolic disorder characterized by an autoimmune response that promotes the destruction of beta-cells within the pancreatic islets, resulting in lifelong inadequate insulin secretion. Encapsulating beta cells inside a semipermeable membrane to protect encapsulated cells from direct contact with the host immune system, is a new way to treat type 1 diabetes without the need for long-term immunosuppression. . In this case, the semipermeable membrane surrounds the cells and allows oxygen, nutrients, and cell products to penetrate bilaterally while...
Preparation of Electro Conductive-piezoelectric Nanocomposite for Cartilage Tissue Engineering
, M.Sc. Thesis Sharif University of Technology ; Ramazani, Ahmad (Supervisor) ; Nasrollahzadeh, Naser (Co-Supervisor)
Abstract
Articular cartilage resides in a complex and dynamic mechanical and biophysical environment in vivo. Chondrocyte physiology and biosynthetic activity is influenced by these signals, allowing them to modulate the structural organization and function of tissue at all stages, including development, growth and repair. . In articular cartilage, during physical activity and mechanical loading, electric signal have been observed in form of stress-generated electric potential following the movement of the positive mobile ions (in interstitial fluid) away from the fixed negative charges.Despite increasing evidence that mechanical and electrical stimuli have positive effects on chondrogenesis, to...
Design of Amniotic Membrane-based Hydrogel for Cardiac Tissue Engineering Application
, M.Sc. Thesis Sharif University of Technology ; Yaghmaei, Sohila (Supervisor) ; Saadatmand, Maryam (Supervisor)
Abstract
Mammalian cardiac tissue lacks the ability to effectively self-regenerate following severe damage. The application of external therapeutic agents with strong mechanical properties is needed to restore its function. Even though conventional therapies have several challenges and limitations, injectable hydrogels, with minimally invasive, can significantly improve cardiac tissue regeneration. Extracellular matrices are the most appropriate biomaterials for synthesizing cardiac scaffolds. The human amniotic membrane obtained from the amniotic sac is a readily available, abundant, and inexpensive candidate that has been successfully utilized for the clinical treatment of cardiac diseases....
Fabrication and Optimizing a Bilayer Scaffold with the Ability to Release Growth Factors in Aim to Treating Injuries in Tissue Engineering
, M.Sc. Thesis Sharif University of Technology ; Shamloo, Amir (Supervisor) ; Hosseini, Vahid (Supervisor)
Abstract
Skin, as the largest organ of the body and the first protector against external injuries, plays an important role in maintaining human health. Therefore, providing a method for complete treatment of skin lesions is very important. In the last century, tissue engineering approaches, with the introduction of skin scaffolds, have been instrumental in the process of skin tissue regeneration and treatment. The aim of the present study is to construct an optimal bilayer scaffold to mimic the two outer layer of the skin (epidermis and dermis). Besides, the effects of placenta extract on acceleration of wound healing was investigated by an in-vivo test. both layer of scaffold are porous hydrogels,...
Charactrization of Oxidized Alginate- Gelatin Composite Hydrogel Reinforcement by Ti3C2Tx Mxene for Utilization in Biomedical Applications
, M.Sc. Thesis Sharif University of Technology ; 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...
Design and Manufacture of Polymeric Nanocomposite in Order to Control the Production and Migration of Sand in Reservoirs
, Ph.D. Dissertation Sharif University of Technology ; Taghikhani, Vahid (Supervisor) ; Baghban Salehi, Mahsa (Supervisor)
Abstract
Sand production from oil reservoirs leads to various problems, such as well productivity reduction, operating equipment corrosion, and increased production costs. Therefore, controlling sand production in unconsolidated reservoirs is crucial for operating companies. Chemical injection into the formation in order to strengthen and reduce sand production is one of the most important methods of sand control. In this study, a hydrogel nanocomposite was designed and its effectiveness in sand control was investigated. Various tests were carried out to define and assess its efficacy, as follows: Morphological tests demonstrated the creation of a dense, homogeneous, and porous structure. Structural...
Applications of stimuli responsive hydrogels: A textile engineering approach
, Article Journal of the Textile Institute ; Volume 104, Issue 11 , 2013 , Pages 1145-1155 ; 00405000 (ISSN) ; Hemmati Nejad, N ; Pourjavadi, A ; Sharif University of Technology
2013
Abstract
Stimuli responsive hydrogels (SRHs) are smart materials with reversible changes in their properties through the environmental stimulus variations. Although SRHs have been used in various medical applications such as sensors, drug release systems and, etc., they are still being actively researched on other sectors such as functional textiles and smart clothing. One of the best methods to produce textiles with more functionality is smart finishing of textile by surface modifying stimuli responsive hydrogels. In this paper, literatures on SRHs applications, methods and application of some SRHs on textile have been thoroughly discussed
Studies on glutaraldehyde crosslinked chitosan hydrogel properties for drug delivery systems
, Article International Journal of Polymeric Materials and Polymeric Biomaterials ; Volume 62, Issue 11 , 2013 , Pages 605-611 ; 00914037 (ISSN) ; Ramazani, S. A. A ; Shafiee, M ; Danaei, M ; Sharif University of Technology
2013
Abstract
Chitosan was crosslinked with different amount of glutaraldehyde to prepare appropriate hydrogels to be used as drug delivery system. The swelling behavior of freeze-dried hydrogels in aqueous media at different temperature and pHs has been examined. The swelling, porosity and biocompatibility behavior of samples were investigated to check effects of polymer/polymer and polymer/drug interactions on these system characteristics. Obtained experimental results illustrates that with increasing crosslinking agent from 0.068 to 0.30, swelling of the prepared samples degrees from 1200% to 600% and pore diameters change from 100 to 500 μm. To investigate systems biocompatibility in gastric...
Novel highly swelling nanoporous hydrogel based on polysaccharide/protein hybrid backbone
, Article Journal of Polymer Research ; Volume 18, Issue 3 , 2011 , Pages 337-346 ; 10229760 (ISSN) ; Pourjavadi, A ; Soleyman, R ; Sharif Unviersity of Technology
2011
Abstract
Novel high capacity swelling nanoporous hydrogel (NPH) was synthesized via graft copolymerization of acrylamide (AAm) onto kappa-carrageenan (kC, as a polysaccharide) and gelatin (as a protein) hybrid backbone, after hydrolysis of this system. The Taguchi method as a strong experimental design tool was used for its optimized synthesis. The Taguchi method was applied for the experimental and standard 9 orthogonal array (OA) with four factors and three levels for each factor. A series of NPHs were synthesized by proposed conditions of Qualitek-4 Software. Considering the results of 9 trials according to analysis of variance (ANOVA), optimum conditions were proposed. The swelling behavior of...
Synthesis and characterization of semi-conductive nanocomposite based on hydrolyzed collagen and in vitro electrically controlled drug release study
, Article Polymer (United Kingdom) ; Volume 76 , October , 2015 , Pages 287-294 ; 00323861 (ISSN) ; Doroudian, M ; Sharif University of Technology
Elsevier Ltd
2015
Abstract
In this study, a semi-conductive nanocomposite for electrically controlled drug delivery is introduced. Hydrolyzed collagen known as a naturally abundant polypeptide was modified with polycaprolactone. This modification changed the mechanical properties of the hydrolyzed-collagen. A hydrogel compound was synthesized through radical co-polymerization of acrylic acid on the backbone of this biocompatible polymer in the presence of a crosslinker. The reaction parameters affecting the water absorbency of the hydrogel were optimized using Taguchi method. In situ polymerization of aniline, incorporated conductive nanofiber pathways throughout the hydrogel matrix. 1H NMR, TGA, AFM, SEM, FTIR,...