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    Fabrication of Graphene/TiO2 Nanowalls as Visible Lights Photocatalysts

    , M.Sc. Thesis Sharif University of Technology Rahimi, Kourosh (Author) ; Akhavan, Omid (Supervisor)
    TiO2 is known as a photocatalyst in near UV-Visible light region with better efficiency compared to other semiconductor photocatalysts. Many attempts have been done to increase the efficiency of this photocatalyst. also, application of 2D carbon nanostructures namely graphene for increasing the photocatalytic activity of TiO2 has shown positive results.
    In this research, we first synthesized Graphene Oxide (GO) suspension by exfolation of graphite oxide suspension. then we fabricated TiO2 thin films on glass substrates by so-called sol-gel method. finally we fabricate Graphene Oxide/TiO2 nanowalls composite films as a photocatalyst in visible light. X-ray photoelectron spectroscopy... 

    Intelligent Drug Delivery System for Cancer Treatment

    , M.Sc. Thesis Sharif University of Technology Bahrami, Flora (Author) ; Abdekhodaie, Mohammad Jafar (Supervisor)
    Drug delivery systems (DDS), which, are sensitive to tumor medium have high importance. one of the most important problem of current treatment of cancer is damage of the normal tissue, which, it is expected to solve by smart drug delivery systems. In such cases, one or more features of cancer medium cause to release of the drug. One of features of cancer medium is high concentration of reactive oxygen species and hydrogen peroxide in the most common between them. The purpose of this study is to build a drug delivery system, which it is sensitive to hydrogen peroxide. This carrier has 4 main parts. The first part is anti-cancer drug, which, it is located in the carrier. Second part is... 

    Cyto and genotoxicities of graphene oxide and reduced graphene oxide sheets on spermatozoa

    , Article RSC Advances ; Vol. 4, issue. 52 , May , 2014 , pp. 27213-27223 ; ISSN: 20462069 Hashemi, E ; Akhavan, O ; Shamsara, M ; Rahighi, R ; Esfandiar, A ; Tayefeh, A. R ; Sharif University of Technology
    Concentration-dependent cyto and genotoxicities of graphene oxide (GO) and reduced GO (rGO) sheets on spermatozoa were studied. rGO sheets with various surface chemical states were achieved using hydrazine (N2H 4) hydrothermal (HT) reactions and green tea polyphenols (GTPs). Although 0.1 μg mL-1 graphene could not change sperm viability and kinetic parameters, <40% and 20% of spermatozoa were viable and progressively motile, after 2 h incubation with 400 μg mL-1 GO or rGO, respectively. All the graphene nanomaterials induced concentration- dependent reductions of adenosine triphosphate and NAD+/NADH produced by spermatozoa for motility and metabolic activity. While GO, N 2H4-rGO, and HT-rGO... 

    Dose-dependent effects of nanoscale graphene oxide on reproduction capability of mammals

    , Article Carbon ; Volume 95 , December , 2015 , Pages 309-317 ; 00086223 (ISSN) Akhavan, O ; Ghaderi, E ; Hashemi, E ; Akbari, E ; Sharif University of Technology
    Elsevier Ltd  2015
    In vivo dose-dependent effects of nanoscale graphene oxide (NGO) sheets on reproduction capability of Balb/C mice were investigated. Biodistribution study of the NGO sheets (intravenously injected into male mice at dose of ∼2000 μg/mL or 4 mg/kg of body weight) showed a high graphene uptake in testis. Hence, in vivo effects of the NGO sheets on important characteristics of spermatozoa (including their viability, morphology, kinetics, DNA damage and chromosomal aberration) were evaluated. Significant in vivo effects was found at the injected concentrations ≥200 μg/mL after (e.g., ∼45% reduction in sperm viability and motility at 2000 μg/mL). Observation of remarkable DNA fragmentations and... 

    Personalized disease-specific protein corona influences the therapeutic impact of graphene oxide

    , Article Nanoscale ; Volume 7, Issue 19 , Apr , 2015 , Pages 8978-8994 ; 20403364 (ISSN) Hajipour, M. J ; Raheb, J ; Akhavan, O ; Arjmand, S ; Mashinchian, O ; Rahman, M ; Abdolahad, M ; Serpooshan, V ; Laurent, S ; Mahmoudi, M ; Sharif University of Technology
    Royal Society of Chemistry  2015
    The hard corona, the protein shell that is strongly attached to the surface of nano-objects in biological fluids, is recognized as the first layer that interacts with biological objects (e.g., cells and tissues). The decoration of the hard corona (i.e., the type, amount, and conformation of the attached proteins) can define the biological fate of the nanomaterial. Recent developments have revealed that corona decoration strongly depends on the type of disease in human patients from which the plasma is obtained as a protein source for corona formation (referred to as the 'personalized protein corona'). In this study, we demonstrate that graphene oxide (GO) sheets can trigger different... 

    Green synthesis of silica nanoparticles from olive residue and investigation of their anticancer potential

    , Article Nanomedicine ; Volume 16, Issue 18 , 2021 , Pages 1581-1593 ; 17435889 (ISSN) Rezaeian, M ; Afjoul, H ; Shamloo, A ; Maleki, A ; Afjoul, N ; Sharif University of Technology
    Future Medicine Ltd  2021
    Graphical abstract

    Mathematical Modeling and Simulation of Hyperbaric Oxygen Therapy in Tumor Growth Process

    , M.Sc. Thesis Sharif University of Technology Baghani, Elham (Author) ; Abdekhodaei, Mohammad Jafar (Supervisor) ; Saadatmand, Maryam (Co-Supervisor)
    Today cancer is one of the leading causes of death worldwide. It is caused by some cells that they gather together in part of the body and they have an abnormal and very high proliferation rate. Investigations on tumors have shown that when tumor volume increases, oxygen concentration in some regions of tumors decreases and this hypoxic condition leads to some cancer hallmarks, e.g. angiogenesis, deregulation of apoptosis, and shift in cell energy sources. So treatment strategies that can increase tissue oxygenation are good choices for cancers. Hyperbaric oxygen therapy (HBOT) which is used to treat diabetic ulcers and carbon monoxide poisoning, have been used experimentally for cancer and... 

    Selective Transfection of Smart Polymeric Nanoparticles Into Reactive Astrocytes in Animal Model of Spinal Cord Injury

    , Ph.D. Dissertation Sharif University of Technology Sabourian, Parinaz (Author) ; Frounchi, Masoud (Supervisor) ; Mashayekhan, Shohreh (Co-Supervisor) ; Kiani, Sahar (Co-Supervisor)
    In this study, chitosan-based nanoparticles were prepared due to their biocompatibility, availability, high loading capacity of drug, stimulus responsive behavior and the presence of active functional groups. Chitosan was chemically functionalized with reactive oxygen species (ROS)-responsive moiety to respond to the oxidative stess and endosomal pH in nerve injuries. To prepare nanoparticles, functinalized chitosan ionically gelated with pH-responsive polyanions with ROS-scavenging properties such as polyacrylic acid and hyaluronic acid. Then, pH- and ROS-responsive nanoparticles were used for selective transfection into reactive astrocytes and axonal regeneration in spinal cord injuries.... 

    Hyperthermia-induced protein corona improves the therapeutic effects of zinc ferrite spinel-graphene sheets against cancer

    , Article RSC Advances ; Vol. 4, issue. 107 , 2014 , p. 62557-62565 Hajipour, M. J ; Akhavan, O ; Meidanchi, A ; Laurent, S ; Mahmoudi, M ; Sharif University of Technology
    Superparamagnetic zinc ferrite spinel-graphene nanostructures were synthesized as potential therapeutic agents in the magnetic targeted photothermal therapy of cancer and/or drug delivery. The global temperature of the solution and the local temperature at the nanoparticle (NP) surface determine the protein corona composition/content, which in turn affects the biological effects of NPs and the corresponding physiological responses. Therefore, it is rational to hypothesize that spinel-graphene nanostructures may have distinct protein corona compositions and contents, and therapeutic and toxic effects under laser irradiation. To assess this hypothesis, the effects of laser irradiation on the... 

    Synthesis of Titania Coated Upconversion Nanoparticles with the Capability of Being Utilized in Photodynamic Therapy Under the Near-Infrared Radiation

    , Ph.D. Dissertation Sharif University of Technology Ghorashi, Maryam Sadat (Author) ; Madaaah Hosseini, Hamid Reza (Supervisor) ; Soleimani, Masoud (Supervisor) ; Mohajerani, Ezeddin (Co-Supervisor)
    Development of novel photosensitizers and photocatalysts with near-infrared (NIR) light activity and efficient sunlight harvesting is of great importance in photodynamic therapy and environmental remediation. In this work, very small (20 nm) upconverter SrF2:Yb,Tm@CaF2:Yb@Fluorine-doped TiO2 heteronanoparticles (denoted as UCNPs@TiO2) with strong UV-blue emission and wide-spectrum photocatalytic activity were synthesized via a facile three-step hydrothermal method, for the first time. The SrF2: Yb,Tm upconverter nanoparticles were produced as the light-emitting core, epitaxially-grown CaF2 : Yb as the middle shell to enhance the Upconversion luminescence efficiency and TiO2 as the... 

    Genotoxicity of graphene nanoribbons in human mesenchymal stem cells

    , Article Carbon ; Volume 54 , 2013 , Pages 419-431 ; 00086223 (ISSN) Akhavan, O ; Ghaderi, E ; Emamy, H ; Akhavan, F ; Sharif University of Technology
    Single-layer reduced graphene oxide nanoribbons (rGONRs) were obtained through an oxidative unzipping of multi-walled carbon nanotubes and a subsequent deoxygenation by hydrazine and bovine serum albumin. Human mesenchymal stem cells (hMSCs) were isolated from umbilical cord blood and used for checking the concentration- and time-dependent cyto- and geno-toxic effects of the rGONRs and reduced graphene oxide sheets (rGOSs). The cell viability assay indicated significant cytotoxic effects of 10 μg/mL rGONRs after 1 h exposure time, while the rGOSs exhibited the same cytotoxicity at concentration of 100 μg/mL after 96 h. The oxidative stress was found as the main mechanism involved in the... 

    Adverse effects of graphene incorporated in TiO 2 photocatalyst on minuscule animals under solar light irradiation

    , Article Journal of Materials Chemistry ; Volume 22, Issue 43 , 2012 , Pages 23260-23266 ; 09599428 (ISSN) Akhavan, O ; Ghaderi, E ; Rahimi, K ; Sharif University of Technology
    The adverse effect of graphene-titanium oxide composite films (containing sheet-like surface morphology) on Caenorhabditis elegans nematodes (as a model for minuscule animals) was investigated in a solar light-induced photocatalytic process. X-ray photoelectron spectroscopy demonstrated photocatalytic reduction of the chemically exfoliated graphene oxide sheets included in the TiO 2 film. Furthermore, formation of TiC and Ti-O-C bonds in the composite film (obtained through annealing at 450 °C in air) resulted in a substantial delay in the recombination rate of the photoexcited electron-hole pairs and more efficient photocatalytic processes. The composite film showed a type of... 

    Effect of formulation factors on the bioactivity of glucose oxidase encapsulated chitosan-alginate microspheres: In vitro investigation and mathematical model prediction

    , Article Chemical Engineering Science ; Volume 125 , March , 2015 , Pages 4-12 ; 00092509 (ISSN) Abdekhodaie, M. J ; Cheng, J ; Wu, X. Y ; Sharif University of Technology
    Elsevier Ltd  2015
    Higher reactive oxygen species (ROS) levels in cancer cells than normal cells have long been recognized, which makes cancer cells more susceptible to excess ROS. Thus oxidation (also called pro-oxidant) therapy has been explored as new cancer therapy regimens. To produce additional ROS, e.g. H2O2 in situ within tumor, we encapsulated glucose oxidase in chitosan-coated alginate-calcium microspheres (GOX-MS) for locoregional treatment and demonstrated its efficacy against cancer cells in vitro and in vivo. Owing to the complex biological functions of ROS, the production rate and amount of H2O2 are critical to achieve therapeutic benefits without causing normal tissue toxicity. This work was... 

    Synthesis of BiOI/ZnFe2O4-Metal-Organic Framework and g-C3N4-Based Nanocomposites for Applications in Photocatalysis

    , Article Industrial and Engineering Chemistry Research ; Volume 58, Issue 23 , 2019 , Pages 9806-9818 ; 08885885 (ISSN) Khasevani, S. G ; Gholami, M. R ; Sharif University of Technology
    American Chemical Society  2019
    A novel binary BiOI/ZnFe2O4 (BZ) with p-n heterojunction based on the different metal-organic framework (MOF) MIL-88B(Fe) and graphite carbon nitride (g-C3N4) as substrates has been designed. As-prepared ternary nanocomposites have been first obtained via a simple hydrothermal system and subsequently deposited onto the MOF and g-C3N4 substrates. The photoactivity of the ternary nanocomposites was evaluated by organic pollutants degradation under LED light. These characterization results indicated that BiOI as a p-type semiconductor was well deposited on the surface of ZnFe2O4 (n-type semiconductors). The p-n heterojunction photocatalyst (BZ) improved the valence band potential of ZnFe2O4 and... 

    Graphene/Cuo2nanoshuttles with controllable release of oxygen nanobubbles promoting interruption of bacterial respiration

    , Article ACS Applied Materials and Interfaces ; Volume 12, Issue 32 , 2020 , Pages 35813-35825 Jannesari, M ; Akhavan, O ; Madaah Hosseini, H. R ; Bakhshi, B ; Sharif University of Technology
    American Chemical Society  2020
    An oxygen nanoshuttle based on a reduced graphene oxide/copper peroxide (rGO/CuO2) nanocomposite has been presented to deliver in situ oxygen nanobubbles (O2 NBs) for combating bacterial infections. In the presence of rGO, the solid source of oxygen (i.e., CuO2) was decomposed (in response to environmental conditions such as pH and temperature) into O2 NBs in a more controllable and long-lasting trend (from 60 to 144 h). In a neutral buffer, the O2 NBs experienced growth and collapse evolutions, creating a dynamic micro-nanoenvironment around the nanocomposite. In addition to effective battling against methicillin-resistant Staphylococcus aureus bacteria, the O2 NBs demonstrated superior... 

    Associations of primary and secondary organic aerosols with airway and systemic inflammation in an elderly panel cohort

    , Article Epidemiology ; Volume 21, Issue 6 , 2010 , Pages 892-902 ; 10443983 (ISSN) Delfino, R. J ; Staimer, N ; Tjoa, T ; Arhami, M ; Polidori, A ; Gillen, D. L ; George, S. C ; Shafer, M. M ; Schauer, J. J ; Sioutas, C ; Sharif University of Technology
    Background: Exposure-response information about particulate air-pollution constituents is needed to protect sensitive populations. Particulate matter <2.5 mm (PM 2.5) components may induce oxidative stress through reactive-oxygen-species generation, including primary organics from combustion sources and secondary organics from photochemically oxidized volatile organic compounds. We evaluated differences in airway versus systemic inflammatory responses to primary versus secondary organic particle components, particle size fractions, and the potential of particles to induce cellular production of reactive oxygen species. Methods: A total of 60 elderly subjects contributed up to 12 weekly... 

    Smart liposomal drug delivery for treatment of oxidative stress model in human embryonic stem cell-derived retinal pigment epithelial cells

    , Article International Journal of Pharmaceutics ; Volume 548, Issue 1 , 2018 , Pages 62-72 ; 03785173 (ISSN) Behroozi, F ; Abdkhodaie, M. J ; Sadeghi Abandansari, H ; Satarian, L ; Kazemi Ashtiani, M ; Jaafari, M. R ; Baharvand, H ; Sharif University of Technology
    Oxidative stress has been implicated in the progression of age-related macular degeneration (AMD). Treatment with antioxidants seems to delay progression of AMD. In this study, we suggested an antioxidant delivery system based on redox-sensitive liposome composed of phospholipids and a diselenide centered alkyl chain. Dynamic light scattering assessment indicated that the liposomes had an average size of 140 nm with a polydispersity index below 0.2. The percentage of encapsulation efficiency of the liposomes was calculated by high-performance liquid chromatography. The carriers were loaded with N-acetyl cysteine as a model antioxidant drug. We demonstrated responsiveness of the nanocarrier... 

    Stimuli-responsive chitosan as an advantageous platform for efficient delivery of bioactive agents

    , Article Journal of Controlled Release ; Volume 317 , 2020 , Pages 216-231 Sabourian, P ; Tavakolian, M ; Yazdani, H ; Frounchi, M ; van de Ven, T. G. M ; Maysinger, D ; Kakkar, A ; Sharif University of Technology
    Elsevier B.V  2020
    Despite a diverse range of active pharmaceutical agents currently at our disposal, high morbidity rate diseases continue to pose a major health crisis globally. One of the important parameters in this regard is the controlled cargo delivery at desired sites. Among a variety of synthetic and natural macromolecular systems, chitosan, an abundant biopolymer, offers a platform for tailored architectures that could have high loading capacity of cargo, target and deliver. Stimuli directed accumulation of vehicles and drug release is an area of direct relevance to biomedical applications. In this review, we highlight essential characteristics of modified chitosan that present themselves for... 

    Electronic structure of some thymol derivatives correlated with the radical scavenging activity: Theoretical study

    , Article Food Chemistry ; Vol. 165, issue , Dec , 2014 , p. 451-459 Jebelli Javan, Ashkan ; Jebeli Javanb, M ; Sharif University of Technology
    Molecules acting as antioxidants capable of scavenging reactive oxygen species (ROS) are of upmost importance in the living cell. Thymol derivatives exhibit various antioxidant activities and potential health benefits. Exploration of structure-radical scavenging activity (SAR) was approached with a wide range of thymol derivatives. To accomplish this task, the DPPH experimental assay along with quantum-chemical calculations were also employed for these compounds. By comparing the structural properties of the derivatives of interest, their antioxidant activity was explained by the formation of an intramolecular hydrogen bond and the presence of unsaturated double bond (–CHdouble bond; length... 

    Cell "vision": Complementary factor of protein corona in nanotoxicology

    , Article Nanoscale ; Volume 4, Issue 17 , 2012 , Pages 5461-5468 ; 20403364 (ISSN) Mahmoudi, M ; Saeedi-Eslami, S. N ; Shokrgozar, M. A ; Azadmanesh, K ; Hassanlou, M ; Kalhor, H. R ; Burtea, C ; Rothen Rutishauser, B ; Laurent, S ; Sheibani, S ; Vali, H ; Sharif University of Technology
    RSC  2012
    Engineered nanoparticles are increasingly being considered for use as biosensors, imaging agents and drug delivery vehicles. Their versatility in design and applications make them an attractive proposition for new biological and biomedical approaches. Despite the remarkable speed of development in nanoscience, relatively little is known about the interaction of nanoscale objects with living systems. In a biological fluid, proteins associate with nanoparticles, and the amount and the presentation of the proteins on their surface could lead to a different in vivo response than an uncoated particle. Here, in addition to protein adsorption, we are going to introduce concept of cell "vision",...