Search for: mesoporous-silica
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    Mesoporous silica nanoparticles (MCM-41) coated PEGylated chitosan as a pH-Responsive nanocarrier for triggered release of erythromycin [electronic resource]

    , Article International Journal of Polymeric Materials and Polymeric Biomaterials ; 2014, Volume 63, Issue 13, Pages 692-697 Pourjavadi, A. (Ali) ; Mazaheri Tehrani, Zahra ; Sharif University of Technology
    A pH-responsive drug delivery system based on core shell structure of mesoporous silica nanoparticle (MSN) and chitosan-PEG copolymer was prepared and characterized by Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), scanning electron microscope (SEM), and high-resolution transmission microscope (HR-TEM) techniques. In order to improve compatibility MSN and drug, mesoporous nanosilica was modified by 3-aminopropyl triethoxysilane. The release of erythromycin (a macrolide antibiotic) as a model drug was investigated in two pHs, 7.4 and 5.5  

    Dendrimer-like supramolecular nanovalves based on polypseudorotaxane and mesoporous silica-coated magnetic graphene oxide: a potential pH-sensitive anticancer drug carrier

    , Article Supramolecular Chemistry ; Volume 28, Issue 7-8 , 2016 , Pages 624-633 ; 10610278 (ISSN) Pourjavadi, A ; Mazaheri Tehrani, Z ; Shakerpoor, A ; Sharif University of Technology
    Taylor and Francis Ltd 
    In the present research, two types of drug carriers based on mesoporous silica-coated magnetic graphene oxide, Fe3O4@GO@mSiO2, were synthesised and the pH-responsive behaviour for doxorubicin release was investigated. One type of the carrier was dendrimer-like multi ethylene amine grafted on Fe3O4@GO@mSiO2 and the other was dendrimer-like supramolecular polypseudorotaxane. Herein, α-cyclodextrin was used in the structure of supramolecular nanoparticles as a gatekeeper to inhibit the drug from escaping at neutral pH (the pH of healthy tissue). The drug release profile showed that the supramolecular nanocarrier was more sensitive to the pH changes. The content of drug release was about 100% at... 

    Phenyltetrazole as a new ligand for immobilization of palladium nanoparticles on SBA‐15: a new robust catalyst with high loading of Pd for rapid oxidation and reduction

    , Article ChemistrySelect ; Volume 3, Issue 24 , 2018 , Pages 6779-6785 ; 23656549 (ISSN) Matloubi Moghaddam, F ; Saberi, V ; Kalvani, P ; Sharif University of Technology
    Wiley-Blackwell  2018
    In this work, a new catalyst based on palladium nanoparticle supported SBA-15 has been introduced. The designed catalyst was characterized by Scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier-transform infrared spectroscopy (FT-IR), Brunauer–Emmett–Teller (BET) surface area analysis, thermo gravimetric analysis (TGA), Energy-dispersive X-ray spectroscopy (EDS) and atomic absorption spectroscopy (AAS) analyses. For the first time, phenyltetrazole has been used as a ligand to the functionalization of SBA-15 to design robust heterogeneous catalyst with high-loading metal for reduction and oxidation in short time using a low amount of the catalyst. © 2018... 

    Design of Drug Nanocarriers Based on Mesoporous Silica Nanoparticles Coated with Smart Polymers

    , Ph.D. Dissertation Sharif University of Technology Mazaheri Tehrani, Zahra (Author) ; Pourjavadi, Ali (Supervisor)
    Mesoporous silica nanoparticles have broad application in drud delivery systems due to their porous structure, functionalization, biocompatibility, high surface area and pore volume. Neverthless, pure mesoporous silica nanoparticles without functionality were not smart material and could not release drug in triggered and controlled manner. For this reason, using smart polymeric coating would be considered. Polymer shells also provide colloidal stability, improved blood circulation lifetime and reduced toxicity which are crucial for efficient in vivo drug delivery. Inflammatory and tumor tissue have low pH and high temperature as compared to health tissue. Therefore, using pH and... 

    PEG-co-polyvinyl pyridine coated magnetic mesoporous silica nanoparticles for pH-responsive controlled release of doxorubicin

    , Article International Journal of Polymeric Materials and Polymeric Biomaterials ; Volume 64, Issue 11 , 2015 , Pages 570-577 ; 00914037 (ISSN) Pourjavadi, A ; Mazaheri Tehrani, Z ; Bennett, C ; Sharif University of Technology
    Taylor and Francis Inc  2015
    In the present work a pH responsive drug nanocarrier based on magnetic mesoporous silica nanoparticles (MMSN) and polyethylene glycol-co-polyvinyl pyridine (PEG-co-PVP) was prepared. The core-shell nanocarrier was formed due to electrostatic interaction between protonated polyvinyl pyridine and surface modified MMSN with carboxylate groups. This carrier was used for pH-controllable doxorubicin release. The maximum release was occurred at pH 5.5 (pH of endosomes). This carrier was characterized by Fourier transform infrared spectroscopy, thermogravimetric analysis, UV-Vis spectrophotometer, scanning electron microscope, and high-resolution transmission electron microscope techniques. Also the... 

    Synthesis of Mesoporous Silica-Magnetite Nanocopmposite for Biological Applications

    , M.Sc. Thesis Sharif University of Technology Bagherzadeh, Elham (Author) ; Madaah Hosseini, Hamid Reza (Supervisor)
    During the most recent years, investigating novel nanomaterials based on porous strucures has become an interesting field of research. Among these kinds of materials, mesoporous silica has extensive applications in catalysis, absorbants and biomedical engineering. By combining specific surface characteristics of mesoporous silica with magnetic properties of iron oxide nanoparticles, new nanocomposites owing unique properties, can be obtained. In the present research, magnetic mesoporous nanocomposite has been synthesized. Iron oxide nanoparticles were produced through reduction of water solution containing Fe2+/Fe3+ ions, followed by hydrothermal treatment of precipitan. Then, iron oxide... 

    Immobilization of Pd Nanoparticles on Functionalized SBA-15 and a Robust Mesoporous Catalyst for Reduction and Oxidation Reactions and Synthesis of Tetrasubstituted Pyrroles Via Multicomponent Reactions

    , M.Sc. Thesis Sharif University of Technology Kalvani, Pedram (Author) ; Matloubi Moghaddam, Firouz (Supervisor)
    In first part Mesoporous silica (SBA-15) was synthesized by template synthesis method and the surface of SBA-15 was functionalized with 3-glycidoxypropyltrimethoxysilane and 5-Phenyl-1H-tetrazole. Palladium nanoparticles were immobilized on the aforementioned mesoporous support. Characterization of catalyst regarding to its structure, morphology and other parameters was investigated by physiochemical analysis such as XRD, SEM, TEM, and TGA. This heterogeneous catalyst has high capability in reduction of nitrobenzenes and selective oxidation of primary alcohols which respectively gain aminoarenes and benzaldehydes in high yields. Reduction and oxidation reactions are done in water as a green... 

    Synthesis of Cationic Mesoporous Silica Nanoparticles as a Carrier for the Deliveryof Nucleic Acids

    , M.Sc. Thesis Sharif University of Technology Kermanshah, Leyla (Author) ; Vosoughi, Manouchehr (Supervisor) ; Arpanaei, Ayyoob (Supervisor) ; Javadi, Hamid Reza (Co-Advisor)
    Mesoporous silica nanoparticles (MSNP) have attracted lots of attentions because of their particular characteristics. Physical characteristics such as structure, morphology, porosity, and size of these nanoparticles have strong impact on their function and it can be conceived a wide range of applications for them by manipulating these characteristics. In this research, monodispersed MSNPs with a controllable size in the range of 50-130 nm and pore size in the range of 4-24 nm were synthesized and positively functionalized in order to develop a carrier for the delivery of nucleic acids (siRNA and pDNA). The MSNPs were synthesized by the template removing method.In this method, sodium... 

    Fabrication and Characterization of a Drug Release System Based on Mesoporous Silica Nanoparticles for Hydrophobic Drugs

    , M.Sc. Thesis Sharif University of Technology Taebnia, Nayyera (Author) ; Yaghmaei, Soheila (Supervisor) ; Arpanaei, Ayyoob (Supervisor) ; Morshedi, Dina (Co-Advisor)
    This research aims to develop a drug delivery system based on mesoporous silica nanoparticles (MSNPs) for hydrophobic drugs and evaluating their cytotoxicity. The internal environment of the body is aqueous, while most of effective drugs display poor aqueous solubility, resulting in insufficient bioavailability. Due to their several unique properties, such as a large surface area, tunable pore size, facile surface multi functionalization and excellent biocompatibility, MSNPs are recognized as promising and powerful tools to overcome this hurdle. In the present study, MSNPs were synthesized using template removing method and then were functionalized through grafting procedure. They were... 

    Targeted Delivery of Curcumin by Mesoporous Silica Nanoparticle Coated with Liposome

    , M.Sc. Thesis Sharif University of Technology Hedayati, Mohammad Hassan (Author) ; Abdekhodaie, Mohammad Jafar (Supervisor) ; Akbari, Hamid (Supervisor)
    Several studies based on anti- cancer, anti- metastatic and anti- tumor effects of curcumin have been reported . Besides these benefits, the therapeutic efficacy of curcumin is limited due to its poor aqueous solubility, extensive first-pass metabolism, inadequate tissue absorption and degradation at alkaline pH, which severely diminishes its bioavailability. In this project we seek to solve some of the problems with nanoscience to work more effectively. In the past decade, mesoporous silica nanoparticles (MSNs) have found widespread application as controlled drug delivery systems. Recent reports on the design of capped and gated MSN-based systems have shown promise in preventing premature... 

    3D Stem Cell Culture and Differentiation Using Alginate Hydrogel Scaffolds Incorporated with Silicon-Based Nanoparticles

    , Ph.D. Dissertation Sharif University of Technology Hassani, Masoud (Author) ; Yaghmaei, Soheila (Supervisor) ; Arpanaei, Ayyoob (Co-Supervisor) ; Dolatshahi Pirouz, Alireza (Co-Supervisor)
    Bone is one of the most vital parts of the body for almost any functional movement. Due to its many involved diseases, traumas and injuries, bone maintenance and regeneration are of high importance. Engineering and design of complex tissues, with impeccable mimicry of the native ones, are always accounted as the solution to dysfunction of body organs due to aging, various diseases, etc. However, the inability to complete mimicry of the native tissue architecture and cell microenvironment are the main barriers to functional tissue regeneration. In this project, in order to design a suitable scaffold for bone regeneration, hydrogel nanocomposites with polysaccharide basis were developed by... 

    Investigation on Effect of Additives on the Synthesis of Mesoporous Silica Nano Particles for Drug Delivery Applications

    , M.Sc. Thesis Sharif University of Technology Askari, Majid (Author) ; Nemati, Ali (Supervisor) ; Akbari, Hmid (Supervisor) ; Khoobi Shourkaei, Mahdi (Co-Supervisor)
    In recent years, the use of mesoporous silica nanoparticles as carriers of biological agents has increased. The use of nanometer dimensions in intra-body applications not only hides the particles from the view of macrophages and the body's immune system, but also causes the particles to enter the cells more easily through endocytosis. Template removal method is the most common method in the synthesis of mesoporous silica. In this method, the orderly arrangement of pattern-forming molecules is used to form pores. Until now, various types of organic materials have been used as pattern materials. The main goal is the synthesis of nanoparticles with the largest size of holes and the largest... 

    Chitosan based supramolecular polypseudorotaxane as a pH-responsive polymer and their hybridization with mesoporous silica-coated magnetic graphene oxide for triggered anticancer drug delivery

    , Article Polymer (United Kingdom) ; Volume 76 , October , 2015 , Pages 52-61 ; 00323861 (ISSN) Pourjavadi, A ; Mazaheri Tehrani, Z ; Jokar, S ; Sharif University of Technology
    Elsevier Ltd  2015
    Chitosan based polyseudorotaxane was designed as a pH-responsive supramolecular polymeric shell around the mesoporous silica-coated magnetic graphene oxide (Fe3O4@GO@mSiO2). It was used for doxorubicin delivery at cancerous tissue in a controlled manner. The core-shell nanocarrier was formed due to electrostatic interaction between chitosan and carboxylated surface of Fe3O4@GO@mSiO2. The maximum release occurred at pH 5.5 (pH of endosomes) because the shell collapsed at this pH. The drug nanocarrier has potential application in tumor therapy due to good pH-sensitive behavior, improved solubility and high colloidal stability in... 

    Curcumin-loaded amine-functionalized mesoporous silica nanoparticles inhibit α-synuclein fibrillation and reduce its cytotoxicity-associated effects

    , Article Langmuir ; Volume 32, Issue 50 , 2016 , Pages 13394-13402 ; 07437463 (ISSN) Taebnia, N ; Morshedi, D ; Yaghmaei, S ; Aliakbari, F ; Rahimi, F ; Arpanaei, A ; Sharif University of Technology
    American Chemical Society  2016
    This study aimed to develop a drug carrier based on amine-functionalized mesoporous silica nanoparticles (AAS-MSNPs) for a poorly water-soluble drug, curcumin (CUR), and to study its effects on α-synuclein (α-Syn) fibrillation and cytotoxicity. Here, we show that AAS-MSNPs possess high values of loading efficiency and capacity (33.5% and 0.45 mg drug/mg MSNPs, respectively) for CUR. It is also revealed that α-Syn species interact strongly with the CUR-loaded AAS-MSNPs, leading to a significant inhibition of the fibrillation process. Furthermore, these samples reduce the toxic effects of CUR. However, drug-loaded AAS-MSNPs do not affect the cytotoxic properties of the formed fibrils... 

    Functionalized mesoporous silica-coated magnetic graphene oxide by polyglycerol-g-polycaprolactone with pH-responsive behavior: designed for targeted and controlled doxorubicin delivery

    , Article Journal of Industrial and Engineering Chemistry ; 2015 ; ISSN: 1226086X Pourjavadi, A ; Tehrani, Z. M ; Jokar, S ; Sharif University of Technology
    In the present work a novel multifunctional drug nanocarrier was prepared. Polyglycerol-. g-polycaprolactone was grafted on Mesoporous silica-coated magnetic graphene oxide. Doxorubicin, as anticancer drug, was loaded on this carrier. The in vitro drug release showed the controlled pH responsive behavior. At the endosomal pH (pH 5.5) the amount of drug release enhanced. This nanocarrier would have potential application in the tumor therapy owing to its biodegradability, controlled release and pH responsive behavior  

    Magnetic graphene oxide mesoporous silica hybrid nanoparticles with dendritic pH sensitive moieties coated by PEGylated alginate-co-poly (acrylic acid) for targeted and controlled drug delivery purposes

    , Article Journal of Polymer Research ; Volume 22, Issue 8 , 2015 ; 10229760 (ISSN) Pourjavadi, A ; Shakerpoor, A ; Tehrani, Z. M ; Bumajdad, A ; Sharif University of Technology
    Kluwer Academic Publishers  2015
    In this study synthesis of a drug delivery system (DDS) is described which has several merits over its counterparts. In order to synthesize this nano-carrier, graphene oxide nano-sheets are used to accommodate MCM-41 nanoparticles. Furthermore Fe3O4 nanoparticles are introduced to this nano-material to produce a traceable nanoparticle. Since cancerous tissues have lower pH than healthy tissues, pH-sensitive oligomers are attached to this nano-material. Finally the nano-carrier is wrapped by a biocompatible shell (PEGylated sodium alginate); this polymeric shell makes the DDS capable of a more controllable drug release. By measuring in vitro situation, ‘loading content%’... 

    The effect of protein corona on doxorubicin release from the magnetic mesoporous silica nanoparticles with polyethylene glycol coating

    , Article Journal of Nanoparticle Research ; Volume 17, Issue 4 , April , 2015 ; 13880764 (ISSN) Pourjavadi, A ; Tehrani, Z. M ; Mahmoudi, N ; Sharif University of Technology
    Kluwer Academic Publishers  2015
    In the present work, biocompatible superparamagnetic iron oxide nanoparticles coated by mesoporous silica were used as drug nanocarriers for doxorubicin (Dox; an anticancer drug) delivery. In biological media, the interaction of protein corona layer with the surface of nanoparticles is inevitable. For this reason, we studied the effect of protein corona on drug release from magnetic mesoporous silica nanoparticles (MMSNs) in human plasma medium. Besides, we used hydrophilic and biocompatible polymer, polyethylene glycol (PEG), to decrease protein corona effects. The results showed the increased Dox release from PEGylated MMSNs compared with bare MMSNs. This result indicated that the coating... 

    Folate-conjugated pH-responsive nanocarrier designed for active tumor targeting and controlled release of gemcitabine

    , Article Pharmaceutical Research ; Volume 33, Issue 2 , 2016 , Pages 417-432 ; 07248741 (ISSN) Pourjavadi, A ; Mazaheri Tehrani, Z ; Abedin Moghanaki, A ; Sharif University of Technology
    Springer New York LLC 
    Purpose: The prime end of this study was to design a novel pH-sensitive as well as a PEGylated dendritic nanocarrier for both controllable and traceable gemcitabine delivery to cancerous cells. To accomplish this goal, we took advantage of a hybrid of nanoparticles including: mesoporous silica, graphene oxide and magnetite. Methods: The nanocarrier was prepared in a multi-step synthesis route. First, magnetite mesoporous silica was deposited on the graphene oxide matrix. Then, polyamidoamine dendrimers (up to generation 1.5) with pentaethylene hexamine end groups were grafted on the surface of the nanoparticles. In order to enhance the biostability, and as the next step, the nanocarrier was... 

    Mesoporous silica nanoparticles with bilayer coating of poly(acrylic acid-co-itaconic acid) and human serum albumin (HSA): A pH-sensitive carrier for gemcitabine delivery

    , Article Materials Science and Engineering C ; Volume 61 , 2016 , Pages 782-790 ; 09284931 (ISSN) Pourjavadi, A ; Mazaheri Tehrani, Z ; Sharif University of Technology
    Novel bilayer coated mesoporous silica nanoparticle (MCM-41) based on pH sensitive poly(acrylic acid-co-itaconic acid) and human serum albumin (HSA) was designed for controlled delivery of gemcitabine (anticancer drug) to cancer cells. The shell around the mesoporous silica has bilayer structure. Poly(acrylic acid-co-itaconic acid) was used as pH-sensitive inner shell and human serum albumin, HSA, was used as outer shell. The core-shell structure was formed due to electrostatic interaction between ammonium groups of modified MCM-41 and carboxylate groups of copolymer. Also, the albumin layer was wrapped around the copolymer coated nanoparticle by electrostatic interaction between ammonium... 

    Poly(N-isopropylacrylamide)-coated β-cyclodextrin–capped magnetic mesoporous silica nanoparticles exhibiting thermal and pH dual response for triggered anticancer drug delivery

    , Article International Journal of Polymeric Materials and Polymeric Biomaterials ; Volume 66, Issue 7 , 2017 , Pages 336-348 ; 00914037 (ISSN) Pourjavadi, A ; Mazaheri Tehrani, Z ; Sharif University of Technology
    Taylor and Francis Inc  2017
    In this research a novel controlled anticancer drug delivery system with dual pH and thermal responses was designed based on magnetic mesoporous silica nanoparticles that were anchored by β-cyclodextrin and coated by poly(N-isopropylacrylamide) (PNIPAM). Results demonstrated that the behavior of doxorubicin (anticancer drug) release depended on pH and temperature conditions. At endosomal pH (pH 5.5) the amount of drug release enhanced because the cap was removed from the pores. Furthermore, PNIPAM shell collapsed above the lower critical solution temperature and the releasing of drug increased. Thus, this nanocarrier would have the potential to be applied in the tumor therapy. © 2017 Taylor...