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Synthesis and Characterization of Hybrid Smart Nanohydrogel Pluronic-Chitosan/Graphene/Magnetic Nanoparticles with Ability of Drug Release to Cure Cancer
, M.Sc. Thesis Sharif University of Technology ; Simchi, Abdolreza (Supervisor) ; Askari, Masoud (Supervisor)
Abstract
In recent years, many efforts have been made in the field of drug delivery with hydrogel nanoparticles. This class of materials has been at the center of attention in medical science due to their improved physical and biological properties including high amount of water preservation, penetration, bio capampatibility and physical structure similar to outside matrices of tissue. Among various applications in medical sciences, drug delivery based on hydrogels is very attractive. Hydrogels can protect drugs from aggressive environmental factors such as pH and thermal changes, and presence of enzymes. The porosity of hydrogels facilitates drug loading into the gel matrix and provides a...
3D Bioprinting of Amniotic Membrane-Based Nanocomposite for Tissue Engineering Applications: Evaluation of Rheological, Mechanical and Biological Properties
, Ph.D. Dissertation Sharif University of Technology ; Simchi, Abdolreza (Supervisor) ; Tamjid, Elnaz (Supervisor) ; Niknejad, Hassan (Co-Supervisor)
Abstract
3D bioprinting is an additive manufacturing method that facilitates the deposition of the desired cells and biomaterials at any pre-defined location. This technique also enables control over the internal structure and external dimensions of printed constructs. Among various biomaterials used as bioinks, the bioinks derived from decellularized extracellular matrixes (dECMs) have attracted significant attention due to their bioactivity and being a rich source of biochemical cues. Here in this study, the decellularized amnion membrane (dAM) has been selected as the main component of the bioink formulation because of its biocompatibility, low immunogenicity, antibacterial property, abundance,...
Synthesis and in Vitro/in Vivo Evaluation of Bioprinted and Core-Shell Systems Containing Proteoglycan Nanoparticle and Growth Factor for Skin Tissue Regeneration
, Ph.D. Dissertation Sharif University of Technology ; Simchi, Abdolreza (Supervisor) ; Shokrgozar, Mohammad Ali (Supervisor) ; Tamjid, Elnaz (Co-Supervisor)
Abstract
Tissue engineering has the potential to revolutionize our health care system. Conceptually, lost or malfunctioning tissues will be replaced by man-made biological substitutes to restore, maintain, or improve function. Tissue engineering has already shown great promise to contribute to treatments of a myriad of diseases including osteoarthritis, cancer, diabetes, skin burns, cardiovascular conditions and various traumatic injuries. Tissue engineering is a highly multidisciplinary discipline that demands integration of knowledge, tools and skills from biology, chemistry, engineering and medicine. Integrating nano- and microtechnologies into clinically sized implants represents a major...
Synthesis and Characterization of Mechanical and Rheological Properties of Interpenetrating Polymer Network Nanocomposite Hydrogels using Nanostructures
, Ph.D. Dissertation Sharif University of Technology ; Bagheri, Reza (Supervisor) ; Kabiri, Kourosh (Supervisor) ; Pourjavadi, Ali (Co-Advisor)
Abstract
Hydrogels are kind of polymers that have ability of frequently applications in agriculture, hygienic, drug delivery and etc. suitable mechanical strength is one of the features of this material. If mechanical strength reduces, efficiency of hydrogels in variety of application will decrease. There are several ways for gel strength improvement, such as cyclic structure for example fumarates, surface crosslinking and preparation of interpenetrating polymer networks (IPNs). Making of nanocomposite structure in hydrogels, using nanostructures, can improve physical-mechanical properties, surprisingly. Therefore, combination of interpenetrating polymer network (IPN) and nanocomposite structures can...
Modelling Nonlinear Viscoelastic Behavior of Hydrogels
, M.Sc. Thesis Sharif University of Technology ; Mohammad Navazi, Hossein (Supervisor) ; Arghavani Hadi, Jamal (Supervisor)
Abstract
In this thesis, the mechanical properties of collagen hydrogels were characterized using Finite Element method and the collagen content effect on the mechanical properties of hydrogels were investigated. Hydrogels samples with different collagen content were assessed which caused diverse mechanical behaviors. Due to the nonlinear behavior of hydrogels, using numerical methods and simulation softwars can be helpful to determine the mechanical properties of these material and save agreat deal of time. Finite Viscoelaticity theory was exploited for a UMAT Subroutine in Abaqus and an special Starin Energy Function was selected to extract the formulations. The agreement between simulation results...
Design of Injectable Hydrogel Scaffold based on Smart Polymer in Tissue Engineering
, M.Sc. Thesis Sharif University of Technology ; Shamloo, Amir (Supervisor)
Abstract
Nerve damage is one of the factors affecting the quality of life of patients. The nervous system does not have the ability to repair large injuries, and autologous transplantation, which is the standard treatment method for nerve injuries, is faced with a shortage of donors and a decrease in the function of the donor site. Tissue engineering hydrogels, due to their similarity to the natural tissue of the stomatal body, are a hope for the repair of nerve tissue. In this research, an injectable, minimally invasive and temperature-sensitive hydrogel based on chitosan-etaglycerophosphate-sodium hydrogen carbonate salt or trisodium phosphate salt containing aligned nanofibers made of gelatin and...
Design and Manufacture of a Scaffold with a Drug Delivery System for a Better Tissue Wound Healing Process
, M.Sc. Thesis Sharif University of Technology ; Shamloo, Amir (Supervisor) ; Aryanpour, Masoud (Supervisor)
Abstract
Articular cartilage is devoid of blood vessels, lymphatics, and nerves which gives it a very limited intrinsic healing and repair capabilities. Being under constant harsh biomechanical environment, makes maintaining the health of articular cartilage a vital principle in having healthy joints. Tissue engineering as a method for regeneration of damaged tissue have attracted a lot of attention. Articular cartilage engineered scaffolds act as a macro scale drug delivery system which in addition to having a good mechanical properties similar to that of cartilage tissue, have to provide a highly porous environment for cell migration and proliferation. The aim of this study is to fabricate a drug...
Fabrication and Optimizing a Bilayer Scaffold with the Ability to Release Growth Factors in Aim to Treating Injuries in Tissue Engineering
, M.Sc. Thesis Sharif University of Technology ; Shamloo, Amir (Supervisor) ; Hosseini, Vahid (Supervisor)
Abstract
Skin, as the largest organ of the body and the first protector against external injuries, plays an important role in maintaining human health. Therefore, providing a method for complete treatment of skin lesions is very important. In the last century, tissue engineering approaches, with the introduction of skin scaffolds, have been instrumental in the process of skin tissue regeneration and treatment. The aim of the present study is to construct an optimal bilayer scaffold to mimic the two outer layer of the skin (epidermis and dermis). Besides, the effects of placenta extract on acceleration of wound healing was investigated by an in-vivo test. both layer of scaffold are porous hydrogels,...
Investigation on Hydrophobic Particle Mobility in Electrolyte Media under Various Electrokinetic Effects
, M.Sc. Thesis Sharif University of Technology ; Seeadi, Mohammad Hassan (Supervisor) ; Kazemzadeh Hannani, Siamak (Co-Supervisor)
Abstract
Electrophoresis of colloidal and bio-particles, which is the motion of a charged particle under an electric field, is a powerful method for the characterization and separation of particles. Electrophoresis of particles could be in electrolyte and gel mediums. Additional drag force is exerted on the particle in a gel medium due to the 3D polymeric structure. Experimental research and molecular dynamics simulations have shown that the no-slip boundary condition is not valuable for many particles in micro and nano-devices. The Navier slip condition, which represents the amount of slip, must replace the no-boundary condition. Characterization of hydrophobicity for optimal design in microfluidic...
Design and Fabrication of a Microfluidic Device for the Formation of Multicellular Aggregates and Using in Tissue Engineering
, Ph.D. Dissertation Sharif University of Technology ; Shamloo, Amir (Supervisor) ; Kazemzadeh, Siamak (Supervisor)
Abstract
Three-dimensional cell culture and forming multicellular aggregates is superior over traditional monolayer approaches due to better mimicking in vivo conditions and hence functions of a tissue. A considerable amount of attention has been devoted to devising efficient methods for the rapid formation of uniform sized multicellular aggregates. Restoring cartilage to healthy state is difficult due to low cell density and hence low regenerative capacity. Currently used platforms are not compatible with clinical translation and require dedicated handling of trained personnel. However, when engineering and implanting cell microaggregates in a higher concentration, new cartilage is efficiently...
Analysis of Photo-Mechanical Response of Light Sensitive Homogeneous Hydrogels
, M.Sc. Thesis Sharif University of Technology ; Naghdabadi, Reza (Supervisor)
Abstract
Light-sensitive hydrogels are advanced materials with modern applications that have the ability to deform with light radiation at specific frequencies. Numerous studies have been conducted to identify the behavior and deformation of these materials. Most studies have experimentally investigated the light-sensitive behavior of hydrogels. On the other hand, modeling the behavior of light-sensitive hydrogels is very complicated, so that the use of these models is possible only in certain cases. Therefore, in the present study, the existing studies have been reviewed in order to simplify the relationships governing the deformation of light-sensitive hydrogels. In this regard, the deformation...
Design and Development of a Compound Skin Scaffold Capable of Drug Delivery for Skin Wound Healing
, M.Sc. Thesis Sharif University of Technology ; Shamloo, Amir (Supervisor) ; Firoozbakhsh, Keykhosrow (Supervisor)
Abstract
Skin tissue as the first protective barrier to the body is always exposed to the most injuries. The purpose of this project is to design an optimum skin scaffold capable of drug delivery for skin wounds healing. To this end, the skin scaffold has been considered as a combination of a hydrogel structure containing polymer microspheres carrying growth factor. Polyvinyl alcohol and sodium alginate polymers were utilized to make the hydrogel substrate. The hydrogel structure was optimized from the viewpoint of the percentage of gelation, water absorption, porosity, mechanical properties, biodegradability, biocompatibility and considering the volume percent of utilized polymers and the...
Fabrication of a Multi-Layered Scaffold to Be Used in Dermal Wound Healing
, M.Sc. Thesis Sharif University of Technology ; Shamloo, Amir (Supervisor) ; Asghari, Mohsen (Co-Advisor)
Abstract
Wound healing by engineered scaffolds is a new step in bio-technology and medical studies in recent years. The goal of the current study is to propose a novel structure for a tissue-engineered scaffold to be used in wound healing. Influenced from the multi-layered structure of natural human skin, the fabricated scaffold consists of two layers to maximize similarity with natural skin. This product is comprised of an electrospun layer made of polycaprolactone and polyvinyl alcohol and a hydrogel layer made of chitosan and gelatin. In order to form a porous medium in the hydrogel layer, freeze-gelation was used instead of freeze drying. The evaluation of fabricated scaffolds was performed by...
Development of an Optimized Skin Scaffold Capable of Growth Factor Release for Acute Skin Wound Healing
, M.Sc. Thesis Sharif University of Technology ; Shamloo, Amir (Supervisor) ; Firoozbakhsh, Keykhosrow (Supervisor)
Abstract
As the first barrier in front of external damages, skin is prone to the largest number of damages applied to one’s body. Acute wounds are considerably prevalent world-widely, imposing very high costs to governments. The purpose of the current project, is to propose a novel skin scaffold capable of growth factor delivery for enhancing the wound healing process in acute wounds. Such a scaffold should be able to decrease the required time for healing process, also to improve the quality of the regenerated skin compared to available commercial products. Furthermore, it should be highly biocompatible, biodegradable, and non-toxic. In this project, to manufacture the artificial skin scaffold, a...
Constitutive Modeling for Transient Swelling Behavior of Polymeric Hydrogel with Large Deformations
, Ph.D. Dissertation Sharif University of Technology ; Naghdabadi, Reza (Supervisor) ; Sohrabpour, Saeed (Supervisor) ; Baghani, Mostafa (Co-Advisor)
Abstract
In this work, the mechanical behavior of smart hydrogels is studied for temperature sensitive and, pH and temperature sensitive ones. First, an equilibrium model is presented for the temperature sensitive hydrogles which is continuous and numerically stable especially in the vicinity of the phase transition temperature. The model results are validated through comparing them with the experimental data available in the literature. The model results are in good agreement with those of experiments especially for hydrogels with high cross-linking density. Then, the model is implemented in a finite element framework by which some homogeneous and inhomogeneous problems are numerically solved....
Development of an Integrated Model of Electricity & Methanol Co Production Through Solar Energy and CO2 Capture
, M.Sc. Thesis Sharif University of Technology ; Saboohi, Yadollah (Supervisor)
Abstract
Emission of CO2 and its diffusion into atmosphere is associated with negative effects on the environmental such as Green House Gases effect. Various techniques of CO2 Capture in energy conversion and processing plant are investigated. A method of CO2 Capture could be based on utilization of solar energy for producing methanol. Basic design of such a system and feasibility analysis of developing that system has been considered on the subject of the present research work. Basic design and commercial feasibility of the system producing methanol through capturing CO2 from exhaust gases of a power plant and hydrogen produced by using solar energy have done such an integrated system. The main...
Charactrization of Oxidized Alginate- Gelatin Composite Hydrogel Reinforcement by Ti3C2Tx Mxene for Utilization in Biomedical Applications
, M.Sc. Thesis Sharif University of Technology ; Nemati, Ali (Supervisor) ; Mashayekhan, Shohreh (Co-Supervisor)
Abstract
Tissue engineering is a science that tries to create new tissues by using cells, growth factors and appropriate biological materials in order to repair damaged organs and replace parts lost due to various reasons. In this research, the effect of adding mxene sheets on the oxidized alginate-gelatin hydrogel scaffold was investigated. For this purpose, mxene nanosheets were first synthesized by Max phase chemical etching and its synthesis was confirmed by X-ray diffraction spectroscoy, field emission scanning electron microscope, X-ray energy diffraction spectroscopy, Fourier-transform infrared spectroscopy, UV-visible spectroscopy. Then, in order to prepare the scaffolds, different amounts of...
Synthesis and Characterization of a Novel Hydrogel Wound Dressing based on Silk Fibroin and Zinc Oxide Nanoparticles
, M.Sc. Thesis Sharif University of Technology ; Nemati, Ali (Supervisor) ; Shokrgozar, Mohammad Ali (Supervisor) ; Farokhi, Mehdi (Co-Supervisor)
Abstract
Recently, some wound dressings have been designed that are expected to enhance the wound healing process and prevent blood bleeding and infection. Polymeric dressings have attracted attention due to their biocompatibility, biodegradability, lack of toxicity, and non-allergenic nature. There is widespread interest in using silk fibroin (SF) for this purpose because of its unique properties. Given these points, we have designed an injectable antioxidant hydrogel wound dressing based on SF and Polydopamine(PDA) modified ZnO nanoparticles. First, ZnO nanoparticles were doped with Cu and then modified with PDA (ZnCuO@PDA). XRD, FTIR, SEM, and TEM characterizations were carried out to confirm the...
Synthesis and Characterization of Tough and Self-healing Nanocomposite Hydrogels of Poly-acrylamide/Alginate
, M.Sc. Thesis Sharif University of Technology ; Pircheraghi, Gholamreza (Supervisor) ; Bagheri, Reza (Supervisor)
Abstract
Hyderogels are hydrophilic polymers with three dimensional network structure, due to their high water absoption, their application to life and industry is increasing from day to day, such as tissue engineering, actuators and sensors, drug delivery and therapeutic treatment. In this project, it has been attempted to produce polyacrylamide/alginate double network hydrogels with the use of graphene oxide nanosheets to indicate that it is possible to combine toughness and self-healing in a hydrogel with the opposite nature of each other. To evaluate mechanical properties, uniaxial tensile test and loading-unloading test were used. The results indicate that increase the weight ratio of acrylamide...
Surface Modification of Bacterial Cellulose-Reinforced Keratin Nanofibers using Pluronic/Gum Tragacanth Hydrogel Nanoparticles Produced by Concurrent gel Electrospray/Polymer Electrospinning Method
, M.Sc. Thesis Sharif University of Technology ; Simchi, Abdolreza (Supervisor) ; Tamjid, Elnaz (Supervisor)
Abstract
In this work, wool keratin/polyethylene oxide (PEO) nanofibrous scaffolds were fabricated by electrospinning method. Bacterial cellulose nanofibrils (BCNFs) were embedded in the electrospun keratin/PEO nanofibers. Incorporation of BCNFs into the nanofibers enhances their hydrophilicity, mechanical properties and cell viability, adhesion and proliferation. Water contact angle of the nanofibers decreased from 126˚ to 83˚by addition of 1 wt % BCNFs. A thermogelling hydrogel based on carboxylated pluronic (Pl-COOH) and gum tragacanth (GT) was fabricated and polymer conjugation was confirmed by FTIR and H-NMR spectroscopy. Morphological and viscoelastic properties of GT-grafted Pl-COOH hydrogels...