Search for: cell-culture
0.007 seconds
Total 223 records

    Spheroids-on-a-chip: recent advances and design considerations in microfluidic platforms for spheroid formation and culture

    , Article Sensors and Actuators, B: Chemical ; Volume 263 , 15 June , 2018 , Pages 151-176 ; 09254005 (ISSN) Moshksayan, K ; Kashaninejad, N ; Ebrahimi Warkiani, M ; Lock, J. G ; Moghadas, H ; Firoozabadi, B ; Saidi, M. S ; Nguyen, N. T ; Sharif University of Technology
    Elsevier B.V  2018
    A cell spheroid is a three-dimensional (3D) aggregation of cells. Synthetic, in-vitro spheroids provide similar metabolism, proliferation, and species concentration gradients to those found in-vivo. For instance, cancer cell spheroids have been demonstrated to mimic in-vivo tumor microenvironments, and are thus suitable for in-vitro drug screening. The first part of this paper discusses the latest microfluidic designs for spheroid formation and culture, comparing their strategies and efficacy. The most recent microfluidic techniques for spheroid formation utilize emulsion, microwells, U-shaped microstructures, or digital microfluidics. The engineering aspects underpinning spheroid formation... 

    Preparation of Gelatin-Alginate Hydrogel for Using as Cell Culture Scaffold

    , M.Sc. Thesis Sharif University of Technology Fadaodini, Samira (Author) ; Mashayekhan, Shohreh (Supervisor) ; Maghsoudi, Vida (Supervisor)
    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... 

    Microcarriers Development for Stem Cells Cultivation

    , M.Sc. Thesis Sharif University of Technology Karimian Shamsabadi, Mohammad (Author) ; Mashayekhan, Shohre (Supervisor) ; Yaghmaei, Soheyla (Supervisor)
    In general, repair and regeneration of damaged tissues or lost organ is base definition of a technology named tissue engineering. Tissue engineering technology provides innovative path to achieve better medical treatment, including different methods which manipulate natural or synthetic biomaterials mimicking stem cells environmental condition inside the body, in order to facilitate desired cell expansion and differentiation. Recently, application of cell carriers in form of microcarriers which are injectable, biodegradable and biocompatible have attracted significant attention. Due to increasing effectiveness in animal cell culture.
    The aim of this work was fabrication of... 

    Synthesis and cyto-genotoxicity evaluation of graphene on mice spermatogonial stem cells

    , Article Colloids and Surfaces B: Biointerfaces ; Volume 146 , 2016 , Pages 770-776 ; 09277765 (ISSN) Hashemi, E ; Akhavan, O ; Shamsara, M ; Daliri, M ; Dashtizad, M ; Farmany, A ; Sharif University of Technology
    Elsevier  2016
    The present study analyzed the dose-dependent cyto- and genotoxicity of graphene oxide and reduced graphene oxide on spermatogonial stem cells (SSCs) for the first time. The results showed that graphene oxide significantly increased oxidative stress at concentrations of 100 and 400 μg/ml, while low concentrations did not have a significant effect. In addition, according to the MTT assay, the cell number decreased in high-concentration (100 and 400 μg/ml) graphene oxide-treated samples compared to untreated cells. However, a reduced graphene-treated sample demonstrated a significant increase in cell number. Moreover, microscopic analysis found high concentrations of graphene nanosheets in... 

    Experimental and Numerical Study of The Production of Alginate Microgels and Cancer Spheroids by Droplet-Based Microfluidic

    , M.Sc. Thesis Sharif University of Technology Rezaeian, Masoud (Author) ; Shamloo, Amir (Supervisor) ; Kazemzadeh Hannani, Siamak (Supervisor)
    Significant advances in biotechnology have led to the emergence of a cost-effective way with less ethical issues to study disease, organ functions, tumors, and their response to drugs besides studying on animals. Microfluidic devices and organ on a chip (tumor on a chip) were introduced to remove those obstacles. Organ on a chip is a powerful tool for studying different types of tissues and simulating diseases, especially cancers, for biological and medical applications. Organ (tumor) on a chip is considered as a smaller scale of the real organ or tumor and it causes to the real-time study of tissues and their functions more accurately. In this study, to fabricate a droplet-based... 

    Downregulation of ITM2A gene expression in macrophages of patients with ankylosing spondylitis

    , Article International Archives of Allergy and Immunology ; Volume 182, Issue 11 , 2021 , Pages 1113-1121 ; 10182438 (ISSN) Lari, A ; Pourbadie, H. G ; Jafari, M ; Sharifi Zarchi, A ; Akhtari, M ; Nejatbakhsh Samimi, L ; Jamshidi, A ; Mahmoudi, M ; Sharif University of Technology
    S. Karger AG  2021
    Objectives: Ankylosing spondylitis (AS) is a rheumatic disorder that is mostly determined by genetic and environmental factors. Given the known importance of macrophage in AS pathogenesis, we investigated the transcriptional profile of macrophage cells in the disease. Methods and Results: Two approaches of differential expression and subsequently, weighted gene co-expression network analysis was utilized to analyze a publicly available microarray dataset of macrophages. Integral membrane protein 2A (ITM2A) was among the most significant genes with a decreased trend in the common results of both methods. In order to confirm the finding, the expression of ITM2A was evaluated in... 

    Experimental Study of Using Cellulosic Compounds in Tissue Engineering

    , M.Sc. Thesis Sharif University of Technology Golizadeh, Mortaza (Author) ; Vossoughi, Manouchehr (Supervisor) ; Karimi, Afzal (Supervisor) ; Faghihi, Faezeh (Co-Supervisor)
    Fabrication and characterization of different surface charged cellulose electrospun scaffolds including cellulose acetate, cellulose, carboxymethyl cellulose and quaternary ammonium cationic cellulose for biomedical applications have been reported in this research. We describe preparation of cellulosic nanofibers through the electrospinning following deacetylation cellulose acetate. Moreover, surface modification of electrospun cellulose nanofibers is carried out to obtain carboxymethyl cellulose and quaternized cellulose nanofibers, respectively. At last, the structural, morphological, mechanical, swelling, wettability and the cell culture properties of the scaffolds were analyzed and... 

    Exploring cellular interactions of liposomes using protein corona fingerprints and physicochemical properties

    , Article ACS Nano ; Volume 10, Issue 3 , 2016 , Pages 3723-3737 ; 19360851 (ISSN) Bigdeli, A ; Palchetti, S ; Pozzi, D ; Hormozi Nezhad, M. R ; Baldelli Bombelli, F ; Caracciolo, G ; Mahmoudi, M ; Sharif University of Technology
    American Chemical Society 
    To control liposomes fate and transport upon contact with biofluids, it is essential to consider several parameters affecting the synthetic and biological identity of liposomes, as well as liposome-protein corona (PC) aspects. As a powerful tool in this data mining adventure, quantitative structure-activity relationship (QSAR) approach is used to correlate physicochemical properties of liposomes and their PC fingerprints to multiple quantified biological responses. In the present study, the relationship between cellular interactions of a set of structurally diverse liposomal formulations and their physicochemical and PC properties has been investigated via linear and nonlinear QSAR models.... 

    Modeling and optimization of gelatin-chitosan micro-carriers preparation for soft tissue engineering: using response surface methodology

    , Article Materials Science and Engineering C ; Volume 75 , 2017 , Pages 545-553 ; 09284931 (ISSN) Radaei, P ; Mashayekhan, S ; Vakilian, S ; Sharif University of Technology
    Electrospray ionization is a wide spread technique for producing polymeric microcarriers (MCs) by applying electrostatic force and ionic cross-linker, simultaneously. In this study, fabrication process of gelatin-chitosan MCs and its optimization using the Response Surface Methodology (RSM) is reported. Gelatin/chitosan (G/C) blend ratio, applied voltage and feeding flow rate, their individual and interaction effects on the diameter and mechanical strength of the MCs were investigated. The obtained models for diameter and mechanical strength of MCs have a quadratic relationship with G/C blend ratio, applied voltage and feeding flow rate. Using the desirability curve, optimized G/C blend... 

    Three-dimensional modeling of avascular tumor growth in both static and dynamic culture platforms

    , Article Micromachines ; Volume 10, Issue 9 , 2019 ; 2072666X (ISSN) Taghibakhshi, A ; Barisam, M ; Saidi, M. S ; Kashaninejad, N ; Nguyen, N. T ; Sharif University of Technology
    MDPI AG  2019
    Microfluidic cell culture platforms are ideal candidates for modeling the native tumor microenvironment because they can precisely reconstruct in vivo cellular behavior. Moreover, mathematical modeling of tumor growth can pave the way toward description and prediction of growth pattern as well as improving cancer treatment. In this study, a modified mathematical model based on concentration distribution is applied to tumor growth in both conventional static culture and dynamic microfluidic cell culture systems. Apoptosis and necrosis mechanisms are considered as the main inhibitory factors in the model, while tumor growth rate and nutrient consumption rate are modified in both quiescent and... 

    Fabrication and characterization of low-cost, bead-free, durable and hydrophobic electrospun membrane for 3D cell culture

    , Article Biomedical Microdevices ; Volume 19, Issue 4 , 2017 ; 13872176 (ISSN) Moghadas, H ; Saidi, M. S ; Kashaninejad, N ; Kiyoumarsioskouei, A ; Trung Nguyen, N ; Sharif University of Technology
    This paper reports the fabrication of electrospun polydimethylsiloxane (PDMS) membranes/scaffolds that are suitable for three-dimensional (3D) cell culture. Through modification the ratio between PDMS and polymethylmethacrylate (PMMA) as carrier polymer, we report the possibility of increasing PDMS weight ratio of up to 6 for electrospinning. Increasing the PDMS content increases the fiber diameter, the pore size, and the hydrophobicity. To our best knowledge, this is the first report describing beads-free, durable and portable electrospun membrane with maximum content of PDMS suitable for cell culture applications. To show the proof-of-concept, we successfully cultured epithelial lung... 

    Flash photo stimulation of human neural stem cells on graphene/TiO 2 heterojunction for differentiation into neurons

    , Article Nanoscale ; Volume 5, Issue 21 , 2013 , Pages 10316-10326 ; 20403364 (ISSN) Akhavan, O ; Ghaderi, E ; Sharif University of Technology
    For the application of human neural stem cells (hNSCs) in neural regeneration and brain repair, it is necessary to stimulate hNSC differentiation towards neurons rather than glia. Due to the unique properties of graphene in stem cell differentiation, here we introduce reduced graphene oxide (rGO)/TiO2 heterojunction film as a biocompatible flash photo stimulator for effective differentiation of hNSCs into neurons. Using the stimulation, the number of cell nuclei on rGO/TiO2 increased by a factor of ∼1.5, while on GO/TiO2 and TiO2 it increased only ∼48 and 24%, respectively. Moreover, under optimum conditions of flash photo stimulation (10 mW cm-2 flash intensity and 15.0 mM ascorbic acid in... 

    A mechanobiological mathematical model of liver metabolism

    , Article Biotechnology and Bioengineering ; Volume 117, Issue 9 , 5 June , 2020 , Pages 2861-2874 Nikmaneshi, M. R ; Firoozabadi, B ; Munn, L. L ; Sharif University of Technology
    John Wiley and Sons Inc  2020
    The liver plays a complex role in metabolism and detoxification, and better tools are needed to understand its function and to develop liver-targeted therapies. In this study, we establish a mechanobiological model of liver transport and hepatocyte biology to elucidate the metabolism of urea and albumin, the production/detoxification of ammonia, and consumption of oxygen and nutrients. Since hepatocellular shear stress (SS) can influence the enzymatic activities of liver, the effect of SS on the urea and albumin synthesis are empirically modeled through the mechanotransduction mechanisms. The results demonstrate that the rheology and dynamics of the sinusoid flow can significantly affect... 

    Design and Construction of Alginate-Silica Nanocomposite and Its Application for Mammalian Cell Culture

    , M.Sc. Thesis Sharif University of Technology Mohammadi Fard, Hossein (Author) ; Vossughi, Manouchehr (Supervisor) ; Arpanaei, Ayyoob (Supervisor) ; Kabir Salmani, Maryam (Co-Advisor)
    Three sizes of silica nanoparticles (160±7, 450±10 and 600±25) were sythetized via template-removing method. The synthetized nanoparticles were functionalized with N-(2-aminoethyl)-3-aminopropyl trimethoxy-silane (EDS) to provide a positive charge on the surface of nanoparticles. BET analysis showed that the average pore diameter, surface area and pore volume of nanoparticles were 2.3 nm, 769 m2.g-1 and 0.44 cm3.g-1, respectively. showed that the Amine-functionalized silica nanoparticles were used to enhance the application of alginate polymer for 3D encapsulation of mammalian cells. Incorporating of silica nanoparticles can be suitable for the bead integrity and attachement of mammalian... 

    Design a Microfluidics System for Drug Testing of Leukemia Patient's Bone Marrow Aspirate

    , M.Sc. Thesis Sharif University of Technology Rahimi, Ali (Author) ; Saidi, Mohammad Said (Supervisor)
    Cancer is one of the most causes of mortality in the world. Leukemia is a type of cancer initiated by the rapid proliferation of blood cells including WBCs, RBCs, and Platelets, that classified into four general types of AML, ALL, CML, and CLL. The main treatment of leukemia is chemotherapy. Because of many problems that patients have with this treatment and not so good results of chemotherapy, we design a microfluidic chip that can perform personalized medicine treatment for leukemia patients.This microchip consists of two main parts, Concentration Gradient Generator (CGG), and cell culture. CGG system is a tree CGG with two inlets and four outlets, which makes a linear concentration of... 

    Design and Fabrication of Microfluidic System as Concentration Gradient Generator

    , M.Sc. Thesis Sharif University of Technology Ziabakhsh, Zeinab Sadat (Author) ; Saadatmand, Maryam (Supervisor)
    According to today’s medicine progress, the need for improving the medical facilities have been increased. Within the human body, the biomolecules concentration gradient is regulating the cell functions. Biological processes such as immune response, wound healing, and cancer metastasis have been affected by the bimolecular concentration gradient. So understanding the cell behavior in the presence of a chemical gradient can improve the understanding from these biological processes, and also would help in medical researches. On the other hand, finding the appropriate dose of the drugs and in some cases finding the most effective drug is a clinical challenge that made a new field of research in... 

    Design and Fabrication of a Microfluidic Chip for Three-dimensional Cancer Cell Culture

    , M.Sc. Thesis Sharif University of Technology Moshksayan, Khashayar (Author) ; Saeedi, Mohammad Saeed (Supervisor) ; Kashaninejad, Navid (Co-Advisor)
    Nowadays, we are witnesses of deaths caused by cancer in large statistical amounts. Vast number of investigations are conducted for anticancer drug evaluation on human and animal cells using traditional two-dimensional and three-dimensional culturing platforms. However, most of them are not successful due to the lack of in-vivo relevant microenvironment in these platforms. One of the best cancer in-vitro cultures is the tumor spheroid which is a spherical cellular aggregation. By culturing these tumor spheroids in a microfluidic chip, it is possible to mimic the in-vivo microenvironment elements such as nutrient and metabolite gradients. Here we present a microfluidic device fabricated using... 

    Functional analyses of recombinant mouse hepcidin-1 in cell culture and animal model

    , Article Biotechnology Letters ; Volume 35, Issue 8 , August , 2013 , Pages 1191-1197 ; 01415492 (ISSN) Yazdani, Y ; Keyhanvar, N ; Kalhor, H. R ; Rezaei, A ; Sharif University of Technology
    Hepcidin is a peptide hormone that plays an important role in iron metabolism. We have produced a recombinant mouse hepcidin-1 by using baculovirus expression system. Its expression yield was 25 μg/ml when cell culture media were supplemented with a protease inhibitor cocktail. The recombinant mouse hepcidin-1 and synthetic human hepcidin-25 had similar effects on reducing ferroportin expression in J774A cell line and in peritoneal macrophages. However, synthetic human hepcidin-25 was more efficient than recombinant mouse hepcidin-1 in reducing iron concentration in blood circulation (p < 0.01)  

    Bacterial leaching of a spent Mo-Co-Ni refinery catalyst using Acidithiobacillus ferrooxidans and Acidithiobacillus thiooxidans

    , Article Hydrometallurgy ; Volume 106, Issue 1-2 , February , 2011 , Pages 26-31 ; 0304386X (ISSN) Gholami, R. M ; Borghei, S. M ; Mousavi, S. M ; Sharif University of Technology
    A spent processing catalyst from an Iranian oil refinery was initially characterized physically and chemically. Acidithiobacillus ferrooxidans and Acidithiobacillus thiooxidans were used to mobilize Al, Co, Mo and Ni from the spent catalysts under optimized conditions in batch cultures. The characteristics of the bioleach solution (pH, Eh, cell concentration and Fe(II)/Fe(III) concentration) were determined along with the concentration of metal values extracted from the catalyst. The results showed that after bioleaching using A. ferrooxidans in the presence of ferrous sulfate, maximum extractions of 63% Al, 96% Co, 84% Mo and 99% Ni were achieved after 30 days at pH 1.8-2.0. However, the... 

    Heavy metals recovery from spent catalyst using acidithiobacillus ferrooxidans and acidithiobacillus thiooxidans

    , Article ICCCE 2010 - 2010 International Conference on Chemistry and Chemical Engineering, Proceedings, 1 August 2010 through 3 August 2010, Kyoto ; 2010 , Pages 331-335 ; 9781424477647 (ISBN) Mafi Gholami, R ; Borghei, S. M ; Mousavi, S. M ; Sharif University of Technology
    In this investigation, a spent processing catalyst from one of the oil refineries in Iran was initially characterized physically and chemically. Acidithiobacillus ferrooxidans and Acidithiobacillus thiooxidans were used to mobilize aluminum, cobalt, molybdenum and nickel from hazardous spent catalysts. Bioleaching experiments were performed in batch cultures. The growth characteristics of the bacteria (pH, Eh, cell concentration and ferrous and ferric iron concentration) were determined during bioleaching along with the concentration of metal values extracted from the catalyst. The results obtained from Inductive coupled plasma-optical emission spectrometry (ICP-OES) showed that after the...