Sharif Digital Repository

Silver nanoparticles (Ag-NPs) are promising agents in bionanotechnology, because of their unique activity against unfavorable processes in bioscience such as undesirable microbial growth, angiogenesis in tumors and etc. Ag-NPs have been widely used in wound dressing; wound healing, water treatment filters, inks, sensors, catalysts, cosmetics, orthopaedics, surgical instruments and vascular prosthesis. Ever-increasing applications of Ag-NPs in biomedical field are due to the anti-bacterial, anti-fungal, anti-viral, anti-platelet, anti-proliferative, anti-inflammatory (apoptosis detection) and anti-angiogenesis properties (cancer therapy). In the current research, we synthesized Ag-NPs in... 

In the past few decades, many attempts have been made to combine the benefits of homogeneous and heterogeneous catalysts. The immobilization of homogeneous catalysts onto the surface of heterogeneous supports is the result of such efforts. In this research, immobilized heterogeneous catalysts were designed and synthesized based on double network hydrogels, which produce from interpenetrating of two biocompatible and biodegradable polymer networks. In order to provide magnetic responsibility and easy separation of catalyst from the reaction mixture, the magnetic nanoparticles were dispersed onto the surface of double network hydrogel. Finally, various metal nanoparticles such as palladium and... 

Photochromism is defined as a reversible transformation of a chemical species between two forms having different absorption spectra induced in one or both directions by photoirradiation. Numerous photochromic molecules were investigated such as spiropyrans (SP), spirooxazines (SO), fulgides, diarylethenes, and azobenzenes. Recently, spirooxazines have been attracted more attention due to their more sensitivity towards photo, pH, heat, pressure, solvent polarity, and high fatigue resistance. Spirooxazine moieties are one of the most popular photochromic groups that can be transformed from colorless closed ring form (SO from) to blue color open ring form by UV irradiation that so-called;... 

In recent years, burns and deep wounds that occur in various accidents are important reasons of death in the world. Therefore, the healing process of burn and full thickness of wounds due to late treatment has always been considered by physicians. Thus, the correct treatment and speed of healing of these types of wounds have always been studied. Many synthetic and natural materials have been used to treat wounds, which among them, hydrogels have received a great attention due to creating a moist environment for wounds and absorbing secretions. However, external mechanical stresses may degrade the therapeutic hydrogel. Recently, self-healing coating hydrogels have been designed and developed... 

Atom transfer radical polymerization (ATRP) is a convenient approach to synthesis of polymer with narrow molecular weight distribution. ATRP of acrylamide (AAm) is taken into consideration because of the intrinsic properties of acrylamide such as water solubility and biocompatibility. As reported in many recent works, polymerization of acrylamide by this method didn’t provide monomodal molecular weight distributions. In best condition with strong ligands such as Me4Cyclam, polymerization was carried out in a short time with high yield but polymerization was not highly controlled. It was shown that polymerization of acrylamide under typical ATRP condition displayed a much lower ATRP... 

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... 

Nowadays, because of the importance of saving energy resources and also environmental issues, utilization of catalysts are increased in industry and products. In the last decades, a lot of efforts have been devoted to develop novel methods for heterogenizing of the homogeneous catalyst in order to combine the advantages of the both the homogeneous and the heterogeneous catalysts. Among the different solid supports, graphene with high surface area and distinctive mechanical and electronical properties have been introduces as an emerging support for heterogenizing of the homogeneous catalysts. On the other hand, the use of ionic liquid has been developed due to a broad range of polarity, low... 

In this thesis, it reports the fabrication of novel magnetic nanocomposites combining the unique properties of magnetic nanoparticles and cross-linked basic polymers that their surface functionalized by suitable groups such as carboxylate groups, pentaethylenehexamine and so on to achieve the maximum adsorption capacity of dyes and heavy metal ions. The performance of the magnetic nanocomposites for removal of anionic and cationic dyes and heavy metal ions were evaluated in different conditions of pH, contact time and initial concentrations. Moreover, the adsorption mechanism was investigated by kinetic models and isotherm studies. The results showed that the abovementioned adsorbents can... 

One of the major problems in cancer treatment is the side effects of the drugs. Nowadays, scientists are developing smart nanocarriers which used for diagnosis and delivering drugs in order to circulate through blood vessels, pass the immune system, attach to cancer cells and kill them without any side effects. In the first research of this thesis, magnetic nanoparticles were coated by modified alginate and used as smart nanocarriers. Magnetic nanocarrier were sysnthesized based on hydrophobic coating of oleic acid and hydrazine oleate-modified alginate shell. The resulting carrier is pH-sensitive and the alginate shell removes in the low pH medium. DOX was placed between hydrophobic chains.... 

In this research we focus on study and fabrication of ZnO composite nanofibers by electrospinning method for photocatalytic application. The most important challenges in the field of photocatalyst are photocatalytic activity under the visible light and efficiency enhancement. ZnO is a wide band gap semiconductor and it is not active under the visible light. In Iran, we have more than 300 sunny days in a year. Therefore fabrication and application of photocatalytic material with activity under the sun light that contained 40% of visible light is so vital in our country. In the first part of this project, ZnO-CNT nanofibers were fabricated and carbon doped in the crystal lattice of the ZnO.... 

Rehabilitation usually involves physical therapy, occupational therapy and counseling for the patient's morale to help to restore his power and performance. Considering the economic outlook and the costs of rehabilitation methods and due to the increasing prevalence of stroke and the need to recover the patients in a short period, only the use of robotic systems opens the door to the medical community. Since a large rehabilitation robots designed and built and each been used according to their advantages and shortcomings. In this project, the major shortcomings examined and exoskeleton designed on two major features including portability and covering shoulder workspace. Shoulder movement was... 

Hydrogels are crosslinked hydrophilic polymers that are capable of imbedding large amounts of water or biological fluids usually to equilibrium. Because of their unique properties, these materials have become ubiquitous and indispensable materials in many applications in recent years. Synthetic methods have produced numerous hydrogel materials with excellent properties. However, their nonbiodegradability might pose long-term environmental problems and limit their use. As a consequence, various research groups have put considerable amounts of effort and resources toward development of new absorbent materials from natural polymers such as polysaccharides. In this research, new hydrogel... 

Conventional chemotherapy methods impact both normal and cancerous cells; therefore, it is essential to design novel drug delivery systems in order to reduce drugs’ side effects. Having high retention time in blood and the capability of crossing blood-brain barriers are the characteristics of nano-scaled drug delivery systems.The research thesis is about the synthesis and characterization of the light-sensitive biocompatible nanogels with the core-shell structure with the intention of Doxorubicin anti-cancer drug delivery. These smart nanogels possess a hydrophobic core coated with hydrophilic starch polymeric chain modified with beta-cyclodextrin. The formation of the core-shell structure... 

Successful formulation development for poor water soluble drugs is a critical, long-standing and challengeable problem in cancer treatment. One of the methods for transporting low-soluble drugs is using nanoparticles which are able to pass through capillary walls of tumor tissues due to their small size. An example of the nanoparticles is micelle systems. Functionalized β-cyclodextrin (β-CD) by hyper branched polyglycerol (HPG) can dissolve low-soluble compounds. This polymer can be used in preparing micelles. In this project, β-cyclodextrin (β-CD) by anionic reactions is initiator for polymerization of glycidol monomer. Hydrophobic cavity of the β-cyclodextrin (β-CD) in placing the phenyl... 

With the fast progress of nanotechnology, targeted drug delivery systems have been widely developed due to decreasing in the drug dosage and subsequently side effects of them into body. These smart systems are able to response to the surroundings stimuli. External stimuli in comparison with internal stimuli are more controllable, and can release drug at the targeted side in the desirable times. In the recent studies, there has been an increasing interest in the usage of LASER as an external stimulus due to high precision, short time response, and suitable practical function. For cancer therapy, several studies have been done by focusing on the hyperthermia effects of gold nanoparticles. In...