Search for: biomaterials
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    Fabrication and evaluation of chitosan/gelatin/PVA hydrogel incorporating honey for wound healing applications: An in vitro, in vivo study

    , Article International Journal of Pharmaceutics ; 2020 Shamloo, A ; Aghababaie, Z ; Afjoul, H ; Jami, M ; Bidgoli, M. R ; Vossoughi, M ; Ramazani, A ; Kamyabhesari, K ; Sharif University of Technology
    Elsevier B.V  2020
    In this study, physically cross-linked hydrogels were developed by freezing-thawing method while different concentrations of honey were included into the hydrogels for accelerated wound healing. The hydrogel was composed of chitosan, polyvinyl alcohol (PVA), and gelatin with the ratio of 2:1:1 (v/v), respectively. Further, the effect of honey concentrations on antibacterial properties, and cell behavior was investigated. In vivo studies, including wound healing mechanism using rat model and histological analysis of section tissue samples were performed. The results illustrated that the incorporation of honey in hydrogels increased the ultimate strain of hydrogels approximately two times,... 

    Glass-ceramics for cancer treatment: So close, or yet so far?

    , Article Acta Biomaterialia ; 2018 ; 17427061 (ISSN) Miola, M ; Pakzad, Y ; Banijamali, S ; Kargozar, S ; Vitale Brovarone, C ; Yazdanpanah, A ; Bretcanu, O ; Ramedani, A ; Vernè, E ; Mozafari, M ; Sharif University of Technology
    After years of research on the ability of glass-ceramics in bone regeneration, this family of biomaterials has shown revolutionary potentials in a couple of emerging applications such as cancer treatment. Although glass-ceramics have not yet reached their actual potential in cancer therapy, the relevant research activity is significantly growing in this field. It has been projected that this idea and the advent of magnetic bioactive glass-ceramics and mesoporous bioactive glasses could result in major future developments in the field of cancer. Undoubtedly, this strategy needs further developments to better answer the critical questions essential for clinical usage. This review aims to... 

    Manufacturing of hydrogel biomaterials with controlled mechanical properties for tissue engineering applications

    , Article Acta Biomaterialia ; Volume 62 , 2017 , Pages 42-63 ; 17427061 (ISSN) Vedadghavami, A ; Minooei, F ; Mohammadi, M. H ; Khetani, S ; Rezaei Kolahchi, A ; Mashayekhan, S ; Sanati Nezhad, A ; Sharif University of Technology
    Hydrogels have been recognized as crucial biomaterials in the field of tissue engineering, regenerative medicine, and drug delivery applications due to their specific characteristics. These biomaterials benefit from retaining a large amount of water, effective mass transfer, similarity to natural tissues and the ability to form different shapes. However, having relatively poor mechanical properties is a limiting factor associated with hydrogel biomaterials. Controlling the biomechanical properties of hydrogels is of paramount importance. In this work, firstly, mechanical characteristics of hydrogels and methods employed for characterizing these properties are explored. Subsequently, the most... 

    Evaluation of Porous NTI SMA Formation Mechanism, Pore Characteristics and Thermo-Mechanical Properties Produced by Power Metallurgy for Biomedical Application

    , M.Sc. Thesis Sharif University of Technology Ghasemi, Abbas (Author) ; Sadrnezhad, Khatiboleslam (Supervisor)
    Porous NiTi specimens were produced by elemental nickel and titanium powders and two different temporary space-holder consisting of NaCl and urea and conventional sintering method. Pore characteristic and morphology of porous NiTi specimens was investigated by optical and electron microscopy. Microstructure of specimens was probed using XRD and SEM. Suitable pore distribution and size for biomedical application was obtained using temporary space-holder method. Porosity content increases with increasing space holder powder. At 70 volume percent space-holder, best pore size and distribution with fully open pores, in size 200-500 µm, was obtained and pores are interconnected that suitable for... 

    “ Nano Oxide Layer Forming on the Surface of Porous Nitinol Shape Memory Alloy for Improving Surface Properties “

    , M.Sc. Thesis Sharif University of Technology Fattahzadeh, Mehrdad (Author) ; Sadrnejhad, Khatiboleslam (Supervisor)
    In this project ,it has been done different surface treatment on 6 samples of nitinol with 40 % prosity,three of them are anodized by H2SO4 ,Hf, Acetic acid, one of them is treated with plasma spray with TIO2 powder, one of them is putted in the furnace at 700 degrees for an hour, and the last one is bare ; Moreover, these treated samples are putted in Simulated body fluid for 16 days . After this period of time, we analyzed the results. Then the cell adhesion amount of osteo blast cells (MG 63) is measured to these samples by immersing them for 3 days in these cells.The results are investigated by SEM ,XRD(X pertpro produced by Panalitical), XRF(530-XRF-01), AAS( AA240), Roughness measuring... 

    The Effect of Thyroid Hormones on The Viscoelastic Behavior of Red Blood Cells

    , M.Sc. Thesis Sharif University of Technology Laktarash, Shaghayegh (Author) ; Seyed Reihani, Nader (Supervisor)
    Blood is one of the most important fluids in the human body, consisting of three parts: red blood cells, white blood cells and platelets. The mechanical properties of red blood cells are important in many diseases. The study of viscosity and other mechanical properties of red blood cells in recent years has attracted the attention of scientists in this field. The mechanical properties of red blood cells are related to the outer membrane and its cytoskeleton, and the study of these components can predict the behavior of red blood cells in diseases. The thyroid gland is located in front of the neck and secretes hormones that control many chemical processes in different parts of the body.... 

    Effects of polydimethylsiloxane grafting on the calcification, physical properties, and biocompatibility of polyurethane in a heart valve

    , Article Journal of Applied Polymer Science ; Volume 98, Issue 2 , 2005 , Pages 758-766 ; 00218995 (ISSN) Dabagh, M ; Abdekhodaie, M. J ; Khorasani, M. T ; Sharif University of Technology
    Segmented polyurethane (PU) has proven to be the best biomaterial for artificial heart valves, but the calcification of polyurethane surfaces causes serious problems in long-term implants. This work was undertaken to evaluate the effects of polydimethylsiloxane (PDMS) grafting on the calcification, biocompatibility, and blood compatibility of polyurethane. A grafted polyurethane film was compared with virgin polyurethane surfaces. Physical properties of the samples were examined using different techniques. The hydrophobicity of the polyurethane films increased as a result of silicone modification. The effects of surface modification of polyurethane films on their calcification and fibroblast... 

    Synthesis and Characterization of Properties of Hybrid Nanoparticles of Gold-graphene

    , M.Sc. Thesis Sharif University of Technology Akhoondi, Soheila (Author) ; Simchi, Abdolreza (Supervisor)
    In recent years utilization of quantum dots for stem cells detection and clean energy production has received intensive attention. Graphene and its derivatives have been widely studied because of their effectiveness on electronical and optoelectronical devices, chemical sensors, nanocomposites, and energy storage. By use of metal nanoparticles, such as AuNPs, we can develop properties of graphene, and control them via shifting the absorption peak wavelength and increasing its biocompatibility. In this research, hybrid nanoparticles of gold-graphene as core-shell and conjugated by polymeric linkers containing amine or thiol functions are synthesized. Our purpose is stabilization the... 

    Experimental Study of Nano-bio Material Injection for Heavy Oil Recovery in Shaly Systems Using Micro-model Apparatus

    , M.Sc. Thesis Sharif University of Technology Mohebbifar, Mahdi (Author) ; Vossoughi, Manouchehr (Supervisor) ; Ghazanfari, Mohammad Hossein (Co-Advisor)
    In this research we aim to find enhance oil recovery mechanisms involved in nano-bio material injection by micro model apparatus which has not been studied before. Especially for injection in heavy oil and shaly porous media that forms most of heavy oil reservoirs. To this end, microscopic images from injection of nano-bio materials to shaly patterns have been taken and analyzed to find the process mechanism. Also amount of enhance oil recovery in different conditions like type of microbe forming bio material, nano-bio material concentration and type of flow pattern (shale characteristics including length, direction and distance from injection and production wells) will be studied.Three... 

    Integrative Utilization of Microenvironments, Biomaterials and Computational Techniques for Advanced Tissue Engineering

    , Article Journal of Biotechnology ; Volume 212 , 2015 , Pages 71-89 ; 01681656 (ISSN) Shamloo, A ; Mohammadaliha, N ; Mohseni, M ; Sharif University of Technology
    Elsevier  2015
    This review aims to propose the integrative implementation of microfluidic devices, biomaterials, and computational methods that can lead to a significant progress in tissue engineering and regenerative medicine researches. Simultaneous implementation of multiple techniques can be very helpful in addressing biological processes. Providing controllable biochemical and biomechanical cues within artificial extracellular matrix similar to in vivo conditions is crucial in tissue engineering and regenerative medicine researches. Microfluidic devices provide precise spatial and temporal control over cell microenvironment. Moreover, generation of accurate and controllable spatial and temporal... 

    Experimental investigation of nano-biomaterial applications for heavy oil recovery in shaly porous models: A pore-level study

    , Article Journal of Energy Resources Technology, Transactions of the ASME ; Volume 137, Issue 1 , August , 2014 ; 01950738 (ISSN) Mohebbifar, M ; Ghazanfari, M. H ; Vossoughi, M ; Sharif University of Technology
    American Society of Mechanical Engineers (ASME)  2014
    Application of nano or biomaterials for enhanced oil recovery (EOR) has been recently much attended by petroleum engineering researchers. However, how would be the displacement mechanisms and how would change the recovery efficiency while nano and biomaterials are used simultaneously is still an open question. To this end, a series of injection tests performed on micromodel containing shale strikes. Three types of biomaterials including biosurfactant, bioemulsifier, and biopolymer beside two types of nanoparticles including SiO2 and TiO2 at different concentrations were used as injection fluids. The microscopic as well as macroscopic efficiency of displacements were observed from analysis of... 

    Design and Optimization of Channeled Hydrogel Scaffold Based on Extracellular Matrix of Heart Tissue with Oxygen Release Capability

    , M.Sc. Thesis Sharif University of Technology Ghasemi, Sara (Author) ; Mashayekhan, Shohreh (Supervisor) ; Khorshidi, Sajedeh (Co-Supervisor)
    Despite the increase in the number of cardiovascular diseases worldwide, the number of new drugs to treat these diseases has been decreasing in the last decade. Current preclinical drug evaluation strategies, which use cell cultures and oversimplified animal models, cannot meet the growing demand for new and effective drugs. In the last decade, the development of microfluidic bioreactors and organ-on-chip systems to improve the drug screening process has been increasing significantly. These systems have shown many advantages over previous preclinical models. Despite all these advantages, keeping the oxygen concentration at the optimal physiological level in microfluidic systems has its own... 

    Microstructure, mechanical properties, corrosion behavior and cytotoxicity of Mg-Zn-Al-Ca alloys as biodegradable materials

    , Article Journal of Alloys and Compounds ; Vol. 607 , 2014 , Pages 1-10 ; ISSN: 09258388 Homayun, B ; Afshar, A ; Sharif University of Technology
    Recently, considerable attentions have been paid to alloy Mg-4Zn-0.2Ca for biomedical applications due to its suitable biocompatibility and acceptable mechanical properties. In this work, the effects of the addition of different amounts of Al on microstructure, mechanical properties, degradation behavior, and biocompatibility of this alloy were investigated. The corrosion behaviors of the alloys were investigated through polarization tests, chronoamperometry analysis, immersion tests, and EIS experiments. The mechanical properties were analyzed by using tensile tests and compression tests. The results showed that the addition of Al up to 3 wt.% considerably modifies the degradation behaviors... 

    State of the art review on design and manufacture of hybrid biomedical materials: Hip and knee prostheses

    , Article Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine ; Volume 231, Issue 9 , 2017 , Pages 785-813 ; 09544119 (ISSN) Bahraminasab, M ; Farahmand, F ; Sharif University of Technology
    The trend in biomaterials development has now headed for tailoring the properties and making hybrid materials to achieve the optimal performance metrics in a product. Modern manufacturing processes along with advanced computational techniques enable systematical fabrication of new biomaterials by design strategy. Functionally graded materials as a recent group of hybrid materials have found numerous applications in biomedical area, particularly for making orthopedic prostheses. This article, therefore, seeks to address the following research questions: (RQ1) What is the desired structure of orthopedic hybrid materials? (RQ2) What is the contribution of the literature in the development of... 

    Development of a genetic algorithm based biomechanical simulation of sagittal lifting tasks

    , Article Biomedical Engineering - Applications, Basis and Communications ; Volume 17, Issue 1 , 2005 , Pages 12-18 ; 10162372 (ISSN) Gündoǧdu, Ö ; Anderson, K. S ; Parnianpour, M ; Sharif University of Technology
    Institute of Biomedical Engineering  2005
    Fibrin sealant and platelet gels are human blood-derived, biodegradable, non toxic, surgical products obtained by mixing a fibrinogen concentrate or a platelet rich plasma with thrombin, respectively. Fibrin sealant is now a well known surgical tool increasingly used to stop or control bleeding, or to provide air and fluid tightness in many surgical situations. Platelet gels are newly developed preparations that are of specific interest because they contain numerous physiological growth factors and cytikines that are released upon the activation of blood platelets by thrombin. These growth factors, including PDGF, TGF-β1, BMP, and VEGF have been shown to stimulate cell growth and... 

    Fabrication and Characterization of Thermoplastic Starch Based Nanocomposite for Bone Scaffold

    , M.Sc. Thesis Sharif University of Technology Mahdieh, Zahra (Author) ; Bagheri, Reza (Supervisor)
    This project aimed to fabricate the bone scaffolds with applying thermoplastic starch-based nano-biocomposites. The starting materials for this scaffold are as follows: thermoplastic starch, ethylene vinyl alcohol as the polymer matrix and nanoforsterite as the ceramic reinforcing phase. Furthermore, vitamin E was used as antioxidant for preserving starch against thermo-mechanical degradations. Likewise, 3D pore structure was developed using azo-dicarbonamide and water in injection moulding process. With blending thermoplastic starch and ethylene vinyl alcohol, some thermoplastic starch’s properties including degradation rate and water absorption were modified. In addition, having... 

    Synthesis of Tin and Ti2n Nanostructured Coatings on Ti alloys Using Magnetron Sputtering System And Comparison of Their Biocompatibility Properties

    , M.Sc. Thesis Sharif University of Technology Kalantari Saghafi, Mahsa (Author) ; Nemati, Ali (Supervisor) ; Khamse, Sara (Supervisor)
    Considering the importance of biocompatibility of implantable prothesis’, metallic alloys have weaker corrosion resistance than ceramics. In order to extend usage of nanomaterials to improve the bio-properties of materials, Nano-structured ceramic coatings are being suggested to improve corrosion resistance and biocompatibility of prosthesis. Meanwhile, very good properties of TiN, such as corrosion resistance and mechanical properties as a thin film coating are undeniable. In this study, TiN and Ti2N thin film were deposited on Ti-based substrate, using PVD and Magnetron sputtering at different argon to nitrogen ratio. The crystal structure of the films was examined using Grazing XRD... 

    Preparation and Characterization of Chitosan-Gelatin/Polyanilne-Graphene-CNT Nanocomposite for Neural Tissue Engineering

    , M.Sc. Thesis Sharif University of Technology Aein Jamshid, Mohammad (Author) ; Ramazani Saadatabadi, Ahmad (Supervisor)
    Repairing and regeneration of neural tissues have attracted considerable attention due to its direct effect on the quality of patients’ lives. Recent developments in nanotechnology and tissue engineering have facilitated their comprehensive applications in the treatment of neurological diseases, and several effective ways have been proposed to repair defects in neural tissues. The main objective of the researches in this field is to regulate cellular behavior and tissue progression through the design and development of synthetic extracellular matrices, such as novel biomaterials, that enhance cell culture and tissue regeneration. Natural polymers, such as chitosan and gelatin, are suitable... 

    Survey of Corrosion and Biocompatibility of Metallic Biomaterials in Simulated Body Fluids

    , M.Sc. Thesis Sharif University of Technology Nourimehr, Omid (Author) ; Afshar, Abdollah (Supervisor)
    In this project, the aim is finding the corrosion behavior and biocompatibility of metallic biomaterials in simulated body fluids.by this study we can have a wide knowledge about the behavior and use of metallic biomaterials.in this project we use three base metals. Ti (grade 5 and grade 2), stainless steel (316L and 316) and Mg alloy(AZ91 and AZ31). the media was six physiological environment( Cigada solution, Hank solution, SBF solution, Fusayama solution, Ringer solution and Tyrod’s solution). all of these environments are related to the body fluids except Fusayama solution that is an artificial saliva and is a mouth fluid. we used polarization tests to determine the corrosion behavior... 

    Scaffold Fabrication for Corneal Regeneration

    , Ph.D. Dissertation Sharif University of Technology Mahdavi Salimi, Sharareh (Author) ; Abdekhodaie, Mohammad Jafar (Supervisor) ; Mashayekhan, Shohreh (Supervisor) ; Baradaran Rafiei, Alireza (Co-Supervisor)
    3D bioprinting technology is a promising approach for corneal stromal tissue regeneration. At first, two different concentrations of GelMA macromer (7.5% and 12.5%) were tested for corneal stroma bioprinting. Due to high macromer concentrations, 12.5% GelMA was stiffer than 7.5% GelMA, which made it easier to handle. In terms of water content and optical transmittance of the bioprinted scaffolds, we observed that scaffold with 12.5% GelMA concentration was closer to the native corneal stroma tissue. Subsequently, cell proliferation, gene and protein expression of human corneal stromal cells encapsulated in the bioprinted scaffolds were investigated. Cytocompatibility in 12.5% GelMA scaffolds...