Loading...
Search for:
agar
0.006 seconds
Synthesis of Superabsorbents Based on Agar and Modified Agar and Investigation of their Applications in Controlled Release of Potassium Nitrate as a Sample of Ionic Fertilizers
, M.Sc. Thesis Sharif University of Technology ; Pourjavadi, Ali (Supervisor)
Abstract
This thesis focouses on the preparation and super-swelling behavior of two superabsorbent hydrogel. In the first section, a new superabsorbent hydrogel based on agar was prepared and the effect of the ratio of some components(AA, AAM, MBA, APS and agar) on the swelling capasity of the hydrogel was studied. Maximum water absorbency of the optimized final product was found to be 614.5 g/g in distilled water. The structure of the hydrogel was characterized by FT-IR method and morphology of the samples was examined by scanning electron microscopy(SEM). Swelling behavior properties of optimized hydrogel sample in different swelling medium were investigated. In the second section, we report the...
PEG-PLA-Polysccharide Injectable Nanogels for Drug Delivery
, M.Sc. Thesis Sharif University of Technology ; Frounchi, Masoud (Supervisor) ; Dadbin, Sousan (Supervisor)
Abstract
In recent years along with time and cost intensive process of developing new and better drugs for diseases like cancer, scientists and researchers are attempting to develop novel drug delivery systems for already existing drugs.The purpose of these novel drug delivery systems such as nanogels is controlling drug release rate as well as delivery to a specific target tissue in order to reduce side effects. One of the most commonly used drugs for cancer treatment is Doxorubicin HCl, commercially known as Adricin. In this project biodegradable and biocompatible polymers PLA and PEG were used to synthesize nanocarriers for Adricin. These nanocarriers were then dispersed in an agar hydrogel. The...
HAP/Agar Nanocarriers for Bone Anti-infection Drug
, M.Sc. Thesis Sharif University of Technology ; Frounchi, Masood (Supervisor)
Abstract
Successful treatment of bone infections is a major orthopedic challenge due to the physiological and anatomical features of bone. In this project, we prepared a drug delivery system with injectable and biodegradable polysaccharide agar containing alginate, polyvinyl alcohol and hydroxyapatite nanocarriers composite microspheres. Alginate and polyvinyl alcohol composite microspheres are crosslinked by calcium and freeze-thawing technique. Using the freeze thawing process for polyvinyl alcohol crosslinking, in addition to alginate crosslinking, improved hydrogel swelling behavior and enhanced drug loading and thus slowed drug release, drug loading increased with increasing PVA percentage from ...
Studying the Effective Factors and Optimizing Enzyme (α-amylase) Separation in Multi-Enzyme Systems by Agarose Column Chromatography
, Ph.D. Dissertation Sharif University of Technology ; Roosta Azad, Reza (Supervisor) ; Soheila Yaghmaee (Supervisor) ; Yeganeh Sarkandi, Shahin (Co-Supervisor)
Abstract
In all types of chromatography for the extraction and purification of proteins, a fixed substrate is needed with which the mobile phase containing the proteins interact with them. This fixed bed should contain grains that have characteristics such as sphericity, high surface area, hydrophilicity, binding power to functional groups, chemical stability, low specific absorption, reusability and low cost. Commercially, the most commonly substrates in the ranges of the molecular weight of proteins are agarose and dextran. Agar was extracted from Gracilaria salicornia seaweed and removal of ionic groups was investigated by three methods. In washing with isopropanol, the ionic groups were reduced...
Synthesis and investigation of swelling behavior of new agar based superabsorbent hydrogel as a candidate for agrochemical delivery
, Article Journal of Polymer Research ; Volume 16, Issue 6 , 2009 , Pages 655-665 ; 10229760 (ISSN) ; Farhadpour, B ; Seidi, F ; Sharif University of Technology
2009
Abstract
In this investigation a new type of superabsorbent hydrogel based on agar was prepared, and the effect of the feed ratio of some components (acrylic acid, MBA, APS and agar) on the swelling capacity of the hydrogel was systematically studied. Maximum water absorbency of the optimized final product was found to be 1,100∈g/g in distilled water. The structure of the hydrogel was characterized by FT-IR method and morphology of the samples was examined by scanning electron microscopy (SEM). Swelling properties of optimized hydrogel sample in different swelling mediums were investigated. The optimum hydrogel were also loaded with potassium nitrate and its potential for controlled release of...
Simulation of DNA electrophoresis through microstructures
, Article Electrophoresis ; Volume 28, Issue 3 , 2007 , Pages 301-308 ; 01730835 (ISSN) ; Sarbolouki, M. N ; Rouhani, S ; Sharif University of Technology
2007
Abstract
The dependence of the mobility of DNA molecules through an hexagonal array of micropillars on their length and the applied electric field was investigated and it was found that mobility is a nonmonotonic function of their length. Results also revealed that the size dependence of the DNA mobility depends on the applied electric field and there is a crossover around E ≈ 25 V/cm for the mobility of λ-DNA and T4-DNA. These observations are explained in terms of the diffusion process inside the structure affected by the solvent and are modeled using the Langevin and its corresponding Fokker-Planck equations. The phenomenon is generalized under three regimes in a phase diagram relating the...
Synthesis of nanobentonite–poly(vinyl alcohol)–bacterial cellulose nanocomposite by electrospinning for wound healing applications
, Article Physica Status Solidi (A) Applications and Materials Science ; Volume 217, Issue 6 , 2020 ; Ghanbari, H ; Mahmoudi, N ; Haramshahi, S. M. A ; Javadpour, J ; Sharif University of Technology
Wiley-VCH Verlag
2020
Abstract
Polymer-based composites are used for wound healing applications. This work aims to prepare an inorganic-polymer nanocomposite based on bentonite, poly(vinyl alcohol), and bacterial cellulose by electrospinning for wound healing. The nanocomposite is synthesized using a solution intercalation technique, with 1–2 wt% nanobentonite concentration variation. The effects of commercial and laboratory-synthesized nanobentonite as well as the extract of the green walnut shell (EGWS) are examined and characterized by different techniques. The addition of nanobentonite increases the average size of fibers and tensile strength up to 200 nm and more than 15 MPa, respectively, due to the presence of...
Cadmium telluride quantum dots induce apoptosis in human breast cancer cell lines
, Article Toxicology and Industrial Health ; Volume 34, Issue 5 , 2018 , Pages 339-352 ; 07482337 (ISSN) ; Zare, H ; Taghavinia, N ; Irajizad, A ; Aghaei, M ; Panjehpour, M ; Sharif University of Technology
SAGE Publications Ltd
2018
Abstract
Introduction: Semiconductor quantum dots (QDs), especially those containing cadmium, have undergone marked improvements and are now widely used nanomaterials in applicable biological fields. However, great concerns exist regarding their toxicity in biomedical applications. Because of the lack of sufficient data regarding the toxicity mechanism of QDs, this study aimed to evaluate the cytotoxicity of three types of QDs: CdTe QDs, high yield CdTe QDs, and CdTe/CdS core/shell QDs on two human breast cancer cell lines MDA-MB468 and MCF-7. Methods: The breast cancer cells were treated with different concentrations of QDs, and cell viability was evaluated via MTT assay. Hoechst staining was...
Amyloid fibril reduction through covalently modified lysine in HEWL and insulin
, Article Archives of Biochemistry and Biophysics ; Volume 727 , 2022 ; 00039861 (ISSN) ; Kalhor, H. R ; Sharif University of Technology
Academic Press Inc
2022
Abstract
Proteins possess a variety of nucleophiles, which can carry out different reactions in the functioning cells. Proteins endogenously and synthetically can be modified through their nucleophilic sites. The roles of these chemical modifications have not been completely revealed. These modifications can alter the protein folding process. Protein folding directly affects the function of proteins. If an error in protein folding occurs, it may cause protein malfunction leading to several neurodegenerative disorders such as Alzheimer's and Parkinson's. In this study, Hen Egg White Lysozyme (HEWL) and bovine insulin, as model proteins for studying the amyloid formation, were covalently attached with...