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biodegradable-polymers
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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...
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...
Synthesis and properties of biodegradable hydrogels of κ-carrageenan grafted acrylic acid-co-2-acrylamido-2-methylpropanesulfonic acid as candidates for drug delivery systems
, Article Reactive and Functional Polymers ; Volume 67, Issue 7 , 2007 , Pages 644-654 ; 13815148 (ISSN) ; Barzegar, Sh ; Zeidabadi, F ; Sharif University of Technology
2007
Abstract
Novel types of highly swelling hydrogels were prepared by grafting crosslinked polyacrylic acid-co-poly-2-acrylamido-2-methylpropanesulfonic acid (PAA-co-PAMPS) chains onto κ-carrageenan through a free radical polymerization method. Here, we propose a mechanism for κ-carrageenan-g-PAA-co-PAMPS formation and confirm the hydrogel structure using FTIR spectroscopy. The effect of grafting variables (i.e. concentration of methylenebisacrylamide (MBA), acrylic acid/-2-acrylamido-2-methylpropanesulfonic acid (AA/AMPS) weight ratio, ammonium persulfate (APS), κ-carrageenan, neutralization percent and reaction temperature) were systematically optimized to achieve a hydrogel with a maximum swelling...
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...
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...
Green composites in bone tissue engineering
, Article Emergent Materials ; 2021 ; 25225731 (ISSN) ; Vahabi, H ; Rabiee, N ; Rabiee, M ; Bagherzadeh, M ; Saeb, M. R ; Sharif University of Technology
Springer Nature
2021
Abstract
Natural and biodegradable polymers are of particular interest as green sources with low-cost and environmentally friendly features, and have been widely used for polymer composite development. The term “Green Composites” refers to polymer/filler systems in which polymer, filler, or sometimes both components are green in view of sources from which they are yielded or their biodegradability. Natural fibers obtained from plants, animals, and/or geological processes are a big class of green sources widely applied in green composite development. There has also been continued research on recycling of green composite as well as developing hybrid systems for advanced applications. In view of their...
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...
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...
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...
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...
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...
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...
Bioresorbable composite polymeric materials for tissue engineering applications
, Article International Journal of Polymeric Materials and Polymeric Biomaterials ; 2020 ; Mohammadi Nasr, S ; Rabiee, N ; Bagherzadeh, M ; Ahmadi, S ; Rabiee, M ; Tahriri, M ; Tayebi, L ; Hamblin, M. R ; Sharif University of Technology
Taylor and Francis Inc
2020
Abstract
This review covers the development of bioresorbable polymeric composites for applications in tissue engineering. Various commercially available bioresobable polymers are described, with emphasis on recent bioresorbable composites based on natural and synthetic polymers. Bioresorbable polymers contain hydrolyzable bonds, which are subjected to chemical degradation via either reactive hydrolysis or enzyme-catalyzed active hydrolysis. For synthetic polymers, chemical hydrolysis is the most important mode of degradation. The degradation rate can be controlled by varying the molecular weight and crystallinity. Examples of bioresorbable polymers are: polyurethane, poly(D,L)lactide,...
Core-sheath gelatin based electrospun nanofibers for dual delivery release of biomolecules and therapeutics
, Article Materials Science and Engineering C ; Volume 108 , 2020 ; Lotfi, R ; Tamjid, E ; Shokrgozar, M. A ; Simchi, A ; Sharif University of Technology
Elsevier Ltd
2020
Abstract
Coaxial electrospinning with the ability to use simultaneously two separate solvents provides a promising strategy for drug delivery. Nevertheless, controlled release of hydrophilic and sensitive therapeutics from slow biodegradable polymers is still challenging. To address this gap, we fabricated core-sheath fibers for dual delivery of lysozyme, as a model protein, and phenytoin sodium as a small therapeutic molecule. The sheath was processed by a gelatin solution while the core fibers were fabricated from an aqueous gelatin/PVA solution. Microstructural studies by transmission and scanning electron microscopy reveal the formation of homogeneous core-sheath nanofibers with an outer and...
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,...
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
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...