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biodegradable-polymers
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Fabrication of Porous Gelatin-based Scaffold and Evaluation of Effect of Gamma Irradiation
, M.Sc. Thesis Sharif University of Technology ; Forounchi, Massoud (Supervisor) ; Dadbin, Susan (Supervisor)
Abstract
Biocompatible porous polymeric scaffolds provide a suitable 3-D environment for proliferation of stem cells in human body. For instance, growth and proliferation concurrent with differentiation of stem cells in such scaffolds can regenerate the tissues or organs. In this attitude we fabricated a porous Gelatin-based scaffold using both of freeze-drying and freeze-extraction methods.Also, effect fo gamma irradiation on microstructure of scaffolds was investigated. In addition, poly(ethylene glycol) was employed to make the scaffold softer. Moreover, effects of various parameters including freezing temperature, cross-linking agent concentration, gelatin and PEG concentrations and their...
Preparation and Investigation of Behavior of PLA/TPS Nanocomposite
, M.Sc. Thesis Sharif University of Technology ; Ramazani Saadat Abadi, Ahmad (Supervisor)
Abstract
With the environmental concerns and scarce supply of the crude oil, a revival in the development of bio-based and compostable materials is coming. They are in general being called the ''green'' materials, among which poly(lactic acid) (PLA) got the most extensive attention due to its good combined properties, including the renewable feedstock, the compostability, and its good mechanical properties, especially the young's modulus and stiffness. PLA has found numerous applications. It is considered having the highest potential to replace some regular petroleum based plastics. However PLA has its own shortcomings, its brittleness, low heat distortion temperature and relatively high cost witch...
Preperation and Properties of Biodegradable Nanocomposites Packaging Films
, M.Sc. Thesis Sharif University of Technology ; Alemzadeh, Iran (Supervisor) ; Vossoughi, Manoochehr (Supervisor)
Abstract
Increasing use of polymeric materials, especially in the packaging industry, besides the problems that exist in recycling these materials, has become a serious concern for the environment. The synthetic polymers are used widely in packaging industry so they have a considerable role in waste production in packaging industry. One way to solve this problem is adding a natural polymer to the synthetic polymer, as a result it becomes friendly environmentally. Starch is one of these natural polymers which is cheap and has the ability to complete degradation in the environment.using row starch in the polymeric compounds causes a severe drop in compound’s properties. For this reason, row starch must...
Drug Retard Release Membrane by Supercritical Systems
, M.Sc. Thesis Sharif University of Technology ; Goodarznia, Iraj (Supervisor) ; Soltanieh, Mohammad (Supervisor)
Abstract
The purpose of the present project is to construct and improve the quality of an absorbable membrane using a supercritical process and study the effects of the operative parameters. Today, usage of biodegradable polymers is intensively increasing and these kinds of polymers are used as drug delivery carrier and tissue engineering medium. A biodegradable membrane is suitable for this goal. In this study Poly Ethylene Glycol (PEG) is used as the biodegradable polymer. Gas anti-solvent (GAS) method was applied for the production of the membrane. The used anti-solvent was Supercritical Carbon Dioxide. In order to study the effects of the operative parameters on the structure of the produced...
Poly (Lactic acid) Synthesis through Polycondensation Method and Optimized Reaction Time
, M.Sc. Thesis Sharif University of Technology ; Frounchi, Masoud (Supervisor) ; Dadbin, Sousan (Supervisor)
Abstract
Poly (Lacticacid) belongs to the family of aliphatic polyesters. PLA can be made from annually renewable resources to yield articles for use in either the industrial packaging field or the biocompatible /bioabsorbable medical device market. Production of PLA through polycondensation in an industrial way was the aim of this project. In order to have the appropriate reaction conditions a steel reactor was designed and constructed. Feasibilty of PLA production in the constructed reactor was investigated and the product was analyzed, using H-NMR and FT-IR spectrum analysis. The average molecular weight was measured by GPC and ubbelohde viscometery method. Studies have shown that oligomerization...
Comparison of kinetic biodegradation of potato starch based and corn starch based low density polyethylene compound in aerated sludge
, Article BioTechnology: An Indian Journal ; Volume 7, Issue 5 , 2013 , Pages 163-168 ; 09747435 (ISSN) ; Khoramnejadian, S ; Hejazi, B ; Sharif University of Technology
2013
Abstract
The biodegradability rates of two different kinds of polyethylene bonded with corn and potato starch are studied in this paper. While it is usual to use soil as the environment for biodegradation, an aerated sludge tank was used in this studywhich offers a richermicrobialmediumand increases the rate of biodegradation. The biodegradability is determined by two ways: first, comparing differences in the weight change of two samples, one placed inside distilled water and the other placed in aerated sludge tank. Second test for biodegradation is by examination of FTIR spectroscopy. Through FTIR spectroscopy, the biodegradability rate and reduction in some of the existing bonds in polymer before...
Thermoplastic starch/ethylene vinyl alcohol/forsterite nanocomposite as a candidate material for bone tissue engineering
, Article Materials Science and Engineering C ; Volume 69 , 2016 , Pages 301-310 ; 09284931 (ISSN) ; Bagheri, R ; Eslami, M ; Amiri, M ; Shokrgozar, M. A ; Mehrjoo, M ; Sharif University of Technology
Elsevier Ltd
Abstract
Recently, biodegradable polymers such as starch based blends have been well renowned in the biomedical field. Studies have considered them suitable for bone scaffolds, bone cements, tissue engineering scaffolds, drug delivery systems and hydrogels. The aim of this study was to synthesize nanocomposite biomaterial consisting a blend of thermoplastic starch and ethylene vinyl alcohol as the polymer matrix, and nano-structured forsterite as the ceramic reinforcing phase for bone tissue engineering applications. Furthermore, vitamin E was applied as a thermal stabilizer during melt compounding. Extrusion and injection molding were incorporated for melt blending and shaping of samples,...
Preparation of biodegradable gelatin/PVA porous scaffolds for skin regeneration
, Article Artificial Cells, Nanomedicine and Biotechnology ; 2016 , Pages 1-8 ; 21691401 (ISSN) ; Dadbin, S ; Frounchi, M ; Rajabi, S ; Sharif University of Technology
Taylor and Francis Ltd
2016
Abstract
Porous scaffolds composed of gelatin/poly (vinyl alcohol), (Gel/PVA), were prepared using combination of freeze gelation and freeze drying methods. The effect of polymer concentration, gelatin/PVA ratio, and glutaraldehyde/gelatin ratio (GA/Gel) was investigated on morphology of pores, swelling ratio, biodegradation, and skin cell culture. At optimum preparation conditions the scaffolds had uniform pore size distributions showing high swelling ratio of 23.6. The scaffolds were of biodegradable nature and almost degraded in 28 days. Human dermal fibroblast cells (HDF) were cultured on the scaffolds and MTS assay was conducted to evaluate the influence of PVA on growth and proliferation of the...
Physical, morphological, and biological studies on PLA/nHA composite nanofibrous webs containing equisetum arvense herbal extract for bone tissue engineering
, Article Journal of Applied Polymer Science ; Volume 134, Issue 39 , 2017 ; 00218995 (ISSN) ; Jafari, S. H ; Zahedi, P ; Bagheri, R ; Hajiaghaee, R ; Sharif University of Technology
Abstract
A series of herbal extract incorporated into poly(lactic acid) (PLA) composite nanofibrous scaffolds were successfully prepared by using electrospinning technique. Equisetum arvense extract (EE) and nanohydroxyapatite (nHA) in different quantities were loaded into PLA solution to fabricate composite nanofibrous webs under various electrospinning conditions. Uniform nanofibers were obtained with an average diameter of 157 ± 47 nm in the case of those containing the herbal extract. Characterization of the webs was carried out by means of Fourier transform infrared (FTIR) spectroscopy, field emission-scanning electron microscopy (FESEM), energy-dispersive X-ray spectroscopy (EDX), and...
Preparation of biodegradable gelatin/PVA porous scaffolds for skin regeneration
, Article Artificial Cells, Nanomedicine and Biotechnology ; Volume 45, Issue 5 , 2017 , Pages 928-935 ; 21691401 (ISSN) ; Dadbin, S ; Frounchi, M ; Rajabi, S ; Sharif University of Technology
Taylor and Francis Ltd
2017
Abstract
Porous scaffolds composed of gelatin/poly (vinyl alcohol), (Gel/PVA), were prepared using combination of freeze gelation and freeze drying methods. The effect of polymer concentration, gelatin/PVA ratio, and glutaraldehyde/gelatin ratio (GA/Gel) was investigated on morphology of pores, swelling ratio, biodegradation, and skin cell culture. At optimum preparation conditions the scaffolds had uniform pore size distributions showing high swelling ratio of 23.6. The scaffolds were of biodegradable nature and almost degraded in 28 days. Human dermal fibroblast cells (HDF) were cultured on the scaffolds and MTS assay was conducted to evaluate the influence of PVA on growth and proliferation of the...
Optimizing the mechanical and physical properties of thermoplastic starch via tuning the molecular microstructure through co-plasticization by sorbitol and glycerol
, Article Polymer International ; Volume 66, Issue 6 , 2017 , Pages 809-819 ; 09598103 (ISSN) ; Pircheraghi, G ; Bagheri, R ; Sharif University of Technology
John Wiley and Sons Ltd
2017
Abstract
Nowadays, environmental hazards caused by plastic wastes are a major concern in academia and industry. Utilization of biodegradable polymers derived from renewable sources for replacing common petroleum-based plastics is a potential solution for reducing the problem. In this regard, starch has become one of the most promising alternatives to non-biodegradable polymers for depleting plastic waste thanks to its low expense, abundance, renewability and biodegradability. However, the main drawbacks of starch are its poor processability, weak mechanical properties and severe hydrophilicity. In this work, thermoplastic starch (TPS) samples have been prepared using glycerol and sorbitol as...
The impact of morphology on thermal properties and aerobic biodegradation of physically compatibilized poly (lactic acid)/co-plasticized thermoplastic starch blends
, Article Polymers for Advanced Technologies ; Volume 29, Issue 12 , 2018 , Pages 2880-2889 ; 10427147 (ISSN) ; Pircheraghi, G ; Bagheri, R ; Altstädt, V ; Sharif University of Technology
John Wiley and Sons Ltd
2018
Abstract
Recently, the use of biodegradable polymers became the applicable solution to reduce the environmental concerns, which are created by plastic wastes as well as restrictions of petroleum-based synthetic polymers. By this point of view, polylactic acid (PLA) as a biodegradable and bio-based polymer is resolving both aforementioned issues. While, the high cost of PLA and its slow biodegradation rate make researchers to blend it with a faster one, for instance, thermoplastic starch (TPS). Adding TPS into PLA can influence on the morphological structure, thermal stability, and biodegradability. In this study, the well-tuned co-plasticized TPS via sorbitol/glycerol mixture was melt mixed with PLA...
Evaluation of bioactivity and biocompatibility of silk fibroin/TiO2 nanocomposite
, Article Journal of Medical and Biological Engineering ; Volume 38, Issue 1 , February , 2018 , Pages 99-105 ; 16090985 (ISSN) ; Madaah Hosseini, H. R ; Taromi, N ; Arasteh, S ; Kazemnejad, S ; Samadi Kuchaksaraei, A ; Sharif University of Technology
Springer Berlin Heidelberg
2018
Abstract
Biodegradable polymer/bioceramic nanocomposites are osteoconductive and can accelerate healing of bone tissue. In this research, silk fibroin (SF)/titanium dioxide (TiO2) nanocomposites were synthesized using different concentrations of TiO2 nanoparticles (0, 5, 10, 15 and 20 wt%). The SF/TiO2 nanocomposites were studied in terms of bioactivity and biocompatibility. The in vitro assessment of osteoblasts compatibility indicated that SF inclusion rendered nanocomposite biocompatible whereas presence of TiO2 nanoparticles allowed the cells to adhere and grow on nanocomposite surface and enhanced the bioactivity of the composite. © 2017, Taiwanese Society of Biomedical Engineering
An analytical model for prediction of controlled release from bulk biodegrading polymer microspheres
, Article Asian Journal of Pharmaceutical and Clinical Research ; Volume 11, Issue 3 , March , 2018 , Pages 432-437 ; 09742441 (ISSN) ; Sharif University of Technology
Innovare Academics Sciences Pvt. Ltd
2018
Abstract
Objective: a convenient numerical model has been developed to predict release profile of different types of agents from bulk biodegrading polymer microspheres, including magnitude methods are less accurate than analytical methods. Usually, this study used analytical solutions for the model and compared the analytical results with numerical solution and experimental data. Methods: The objective drug controlled release profiles were modeled based on a four-phase pattern. Then, a specific formulation was considered based on Fick’s second law. After calculating various parameters, the equations were solved using an analytical method. Results: Comparison results showed that analytical solution...
Electrospray: novel fabrication method for biodegradable polymeric nanoparticles for further applications in drug delivery systems
, Article NANOCON 2009 - 1st International Conference, Conference Proceedings ; 2009 , Pages 324-331 ; 9788087294130 (ISBN) ; Vossoughi, M ; Sharif University of Technology
TANGER Ltd
2009
Abstract
Electrospray is an old processing technique that has recently been rediscovered. This technology is revolutionizing the biomaterials and nanotechnology fields by opening up new areas of research in fabricating drug delivery nano-devices. Due to their size, nanoparticles have the advantage of reaching less accessible sites in the body by escaping phagocytosis and entering tiny capillaries. Nanoparticles also have the unique property to accumulate at the site of inflammation and therefore, are very suitable for targeted drug delivery. The feasibility of fabricating relatively monodispersed polymeric nanoparticles by electrospray method in a modified electrospray setup is demonstrated in this...
Property Investigation of Poly (Ethylene Co-vinyl Acetate)/Poly (l-Lactic Acid)/Organo Clay Nanocomposites
, Article Journal of Polymers and the Environment ; Volume 27, Issue 12 , 2019 , Pages 2886-2894 ; 15662543 (ISSN) ; Ramazani SaadatAbadi, A ; Sharif University of Technology
Springer New York LLC
2019
Abstract
In this study, EVAc/PLA/organo clay nanocomposites were prepared via solution mixing method. The SEM images were used to investigate the morphology of nanocomposites revealing no phase separation or agglomeration of disperse phase in EVAc/PLA blends and nanocomposites. SAXS spectra confirmed the intercalated morphology of nanocomposites. Soil burial test were carried out and the rate of degradation of the samples were measured indirectly. Oxygen gas permeability of EVAc was slightly decreased by adding PLA to the matrix, when small loads of clay caused dramatic improvement in barrier properties. Melt rheological frequency sweep test illustrated the compatibility of EVAc with low contents of...
Poly(lactic acid)/coplasticized thermoplastic starch blend: Effect of plasticizer migration on rheological and mechanical properties
, Article Polymers for Advanced Technologies ; Volume 30, Issue 4 , 2019 , Pages 839-851 ; 10427147 (ISSN) ; Pircheraghi, G ; Bagheri, R ; Altstädt, V ; Sharif University of Technology
John Wiley and Sons Ltd
2019
Abstract
Polylactic acid (PLA) and thermoplastic starch (TPS) are known as bio-based and biodegradable thermoplastic polymers that can be used in different applications owing to their inherent physical and mechanical properties. In order to reduce the higher costs of PLA and tuning its physical and mechanical properties suitable for short life packaging applications, blending of PLA with the TPS, more economical biodegradable polymer, has been considered in academic and industrial researches. However, melt blending of PLA with TPS without compatibilization process caused some drawbacks such as coarsening morphology and declining mechanical properties and ductility because of thermodynamic...
Investigation of the interactions between Melittin and the PLGA and PLA polymers: Molecular dynamic simulation and binding free energy calculation
, Article Materials Research Express ; Volume 6, Issue 5 , 2019 ; 20531591 (ISSN) ; Moosavi, A ; Sharif University of Technology
Institute of Physics Publishing
2019
Abstract
Nanobiotechnology is the application of nanotechnology in nanomedicine. Recently, the use of antimicrobial peptides as a substitute for antibiotics and anticancer drugs has attracted increasing attention. Therefore, the study of the structural behavior of these peptides such as Melittin and their interactions with biocompatible and biodegradable polymers is important. This study was performed to evaluate the critical interactions in the formation of the Melittin-polymers complexes. The aim of the current study was to investigate molecular mechanisms of Melittin encapsulation in biopolymers by molecular dynamics (MD) simulation. The results indicated that the basic residues of Melittin could...
Investigation of the interactions between Melittin and the PLGA and PLA polymers: Molecular dynamic simulation and binding free energy calculation
, Article Materials Research Express ; Volume 6, Issue 5 , 2019 ; 20531591 (ISSN) ; Moosavi, A ; Sharif University of Technology
Institute of Physics Publishing
2019
Abstract
Nanobiotechnology is the application of nanotechnology in nanomedicine. Recently, the use of antimicrobial peptides as a substitute for antibiotics and anticancer drugs has attracted increasing attention. Therefore, the study of the structural behavior of these peptides such as Melittin and their interactions with biocompatible and biodegradable polymers is important. This study was performed to evaluate the critical interactions in the formation of the Melittin-polymers complexes. The aim of the current study was to investigate molecular mechanisms of Melittin encapsulation in biopolymers by molecular dynamics (MD) simulation. The results indicated that the basic residues of Melittin could...
Polymeric carriers for enhanced delivery of probiotics
, Article Advanced Drug Delivery Reviews ; Volume 161-162 , 2020 , Pages 1-21 ; Pourjavadi, A ; Licht, T. R ; Boisen, A ; Ajalloueian, F ; Sharif University of Technology
Elsevier B.V
2020
Abstract
Probiotics are live microorganisms (usually bacteria), which are defined by their ability to confer health benefits to the host, if administered adequately. Probiotics are not only used as health supplements but have also been applied in various attempts to prevent and treat gastrointestinal (GI) and non-gastrointestinal diseases such as diarrhea, colon cancer, obesity, diabetes, and inflammation. One of the challenges in the use of probiotics is putative loss of viability by the time of administration. It can be due to procedures that the probiotic products go through during fabrication, storage, or administration. Biocompatible and biodegradable polymers with specific moieties or pH/enzyme...