Development and characterization of biodegradable polymer blends - PHBV/PCL irradiated with gamma rays

International Nuclear Information System (INIS)

Rosario, F.; Casarin, S.A.; Agnelli, J.A.M.; Souza Junior, O.F. de

2010-01-01

This paper presents the results of a study that aimed to develop PHBV biodegradable polymer blends, in a major concentration with PCL, irradiate the pure polymers and blends in two doses of gamma radiation and to analyze the changes in chemical and mechanical properties. The blends used in this study were from natural biodegradable copolymer poly (hydroxybutyrate-valerate) (PHBV) and synthetic biodegradable polymer poly (caprolactone) (PCL 2201) with low molar mass (2,000 g/mol). Several samples were prepared in a co-rotating twin-screw extruder and afterwards, the tensile specimens were injected for the irradiation treatment with 50 kGy to 100 kGy doses and for the mechanical tests. The characterization of the samples before and after the irradiation treatments was performed through scanning electron microscopy (SEM), dynamic mechanical thermal analysis (DMTA), differential scanning calorimetry (DSC) and mechanical tensile tests. (author)

Biodegradable Polymers and Stem Cells for Bioprinting.

Science.gov (United States)

Lei, Meijuan; Wang, Xiaohong

2016-04-29

It is imperative to develop organ manufacturing technologies based on the high organ failure mortality and serious donor shortage problems. As an emerging and promising technology, bioprinting has attracted more and more attention with its super precision, easy reproduction, fast manipulation and advantages in many hot research areas, such as tissue engineering, organ manufacturing, and drug screening. Basically, bioprinting technology consists of inkjet bioprinting, laser-based bioprinting and extrusion-based bioprinting techniques. Biodegradable polymers and stem cells are common printing inks. In the printed constructs, biodegradable polymers are usually used as support scaffolds, while stem cells can be engaged to differentiate into different cell/tissue types. The integration of biodegradable polymers and stem cells with the bioprinting techniques has provided huge opportunities for modern science and technologies, including tissue repair, organ transplantation and energy metabolism.

FDA-Approved Natural Polymers for Fast Dissolving Tablets

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Md Tausif Alam

2014-01-01

Full Text Available Oral route is the most preferred route for administration of different drugs because it is regarded as safest, most convenient, and economical route. Fast disintegrating tablets are very popular nowadays as they get dissolved or facilely disintegrated in mouth within few seconds of administration without the need of water. The disadvantages of conventional dosage form, especially dysphagia (arduousness in swallowing, in pediatric and geriatric patients have been overcome by fast dissolving tablets. Natural materials have advantages over synthetic ones since they are chemically inert, non-toxic, less expensive, biodegradable and widely available. Natural polymers like locust bean gum, banana powder, mango peel pectin, Mangifera indica gum, and Hibiscus rosa-sinenses mucilage ameliorate the properties of tablet and utilized as binder, diluent, and superdisintegrants increase the solubility of poorly water soluble drug, decrease the disintegration time, and provide nutritional supplement. Natural polymers are obtained from the natural origin and they are cost efficacious, nontoxic, biodegradable, eco-friendly, devoid of any side effect, renewable, and provide nutritional supplement. It is proved from the studies that natural polymers are more safe and efficacious than the synthetic polymers. The aim of the present article is to study the FDA-approved natural polymers utilized in fast dissolving tablets.

Biodegradable Polymers and Stem Cells for Bioprinting

Directory of Open Access Journals (Sweden)

Meijuan Lei

2016-04-01

Full Text Available It is imperative to develop organ manufacturing technologies based on the high organ failure mortality and serious donor shortage problems. As an emerging and promising technology, bioprinting has attracted more and more attention with its super precision, easy reproduction, fast manipulation and advantages in many hot research areas, such as tissue engineering, organ manufacturing, and drug screening. Basically, bioprinting technology consists of inkjet bioprinting, laser-based bioprinting and extrusion-based bioprinting techniques. Biodegradable polymers and stem cells are common printing inks. In the printed constructs, biodegradable polymers are usually used as support scaffolds, while stem cells can be engaged to differentiate into different cell/tissue types. The integration of biodegradable polymers and stem cells with the bioprinting techniques has provided huge opportunities for modern science and technologies, including tissue repair, organ transplantation and energy metabolism.

The effect of gamma-radiation on biodegradability of natural FIBER/PP-HMSPP foams: A study of thermal stability and biodegradability

International Nuclear Information System (INIS)

Cardoso, Elizabeth C.L.; Scagliusi, Sandra R.; Lugao, Ademar B.

2015-01-01

This research was carried out to evaluate how gamma-radiation affected PP/HMSPP structural foams reinforced with sugarcane bagasse, in terms of thermal properties, biodegradability and infrared spectrum. Polymers are used in various applications and in different industrial areas providing enormous quantities of wastes in environment, contributing with 20 to 30% of total volume of solid residues. Besides, shortage of plastics resins obtained from oil and natural gas is addressing research and development toward alternative materials; environmental concerning in litter reduction is being directed to renewable polymers for manufacturing of polymeric foams. Biodegradable polymers, a new generation of polymers produced from various natural resources, environmentally safe and friendly, can contribute for pollution reduction, at a low cost. High density structural foams are specially used in civil construction, in replacement of metals, woods and concrete, but contribute for environmental pollution, due to components nature. In this study, it was incorporated sugarcane bagasse in PP/HMSPP polymeric matrix blends. Gamma radiation applied at 50, 100, 150, 200 and 500 kGy doses showed effective for biodegradability induction. TGA analyses pointed toward stability around 205 deg C; decomposition of both cellulose and hemicellulose took place at 310 deg C and above, whereas the degradation of reinforced fibers composites took place above 430 deg C. Infrared spectrum of foams were studied using FTIR, showing no sensitivity to the presence of C = C and C =O functional groups. (author)

The effect of gamma-radiation on biodegradability of natural FIBER/PP-HMSPP foams: A study of thermal stability and biodegradability

Energy Technology Data Exchange (ETDEWEB)

Cardoso, Elizabeth C.L.; Scagliusi, Sandra R.; Lugao, Ademar B., E-mail: eclcardo@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

2015-07-01

This research was carried out to evaluate how gamma-radiation affected PP/HMSPP structural foams reinforced with sugarcane bagasse, in terms of thermal properties, biodegradability and infrared spectrum. Polymers are used in various applications and in different industrial areas providing enormous quantities of wastes in environment, contributing with 20 to 30% of total volume of solid residues. Besides, shortage of plastics resins obtained from oil and natural gas is addressing research and development toward alternative materials; environmental concerning in litter reduction is being directed to renewable polymers for manufacturing of polymeric foams. Biodegradable polymers, a new generation of polymers produced from various natural resources, environmentally safe and friendly, can contribute for pollution reduction, at a low cost. High density structural foams are specially used in civil construction, in replacement of metals, woods and concrete, but contribute for environmental pollution, due to components nature. In this study, it was incorporated sugarcane bagasse in PP/HMSPP polymeric matrix blends. Gamma radiation applied at 50, 100, 150, 200 and 500 kGy doses showed effective for biodegradability induction. TGA analyses pointed toward stability around 205 deg C; decomposition of both cellulose and hemicellulose took place at 310 deg C and above, whereas the degradation of reinforced fibers composites took place above 430 deg C. Infrared spectrum of foams were studied using FTIR, showing no sensitivity to the presence of C = C and C =O functional groups. (author)

Computational analysis for biodegradation of exogenously depolymerizable polymer

Science.gov (United States)

Watanabe, M.; Kawai, F.

2018-03-01

This study shows that microbial growth and decay in a biodegradation process of exogenously depolymerizable polymer are controlled by consumption of monomer units. Experimental outcomes for residual polymer were incorporated in inverse analysis for a degradation rate. The Gauss-Newton method was applied to an inverse problem for two parameter values associated with the microbial population. A biodegradation process of polyethylene glycol was analyzed numerically, and numerical outcomes were obtained.

Modern mass spectrometry in the characterization and degradation of biodegradable polymers

International Nuclear Information System (INIS)

Rizzarelli, Paola; Carroccio, Sabrina

2014-01-01

Graphical abstract: -- Highlights: •Recent trends in the structural characterization of biodegradable polymers by MALDI and ESI MS are discussed. •MALDI MS as a noteworthy tool to follow the synthetic polymerization route of biodegradable materials is evidenced. •Elucidation of degradation mechanisms by modern MS techniques is examined. •ESI MS and HPLC–ESI MS are highlighted as highly suitable methods for structural and quantitative analysis of water-soluble biodegradation products. •Novel MS methods developed ad hoc and new MALDI matrices for biodegradable polymers are reviewed. -- Abstract: In the last decades, the solid-waste management related to the extensively growing production of plastic materials, in concert with their durability, have stimulated increasing interest in biodegradable polymers. At present, a variety of biodegradable polymers has already been introduced onto the market and can now be competitive with non biodegradable thermoplastics in different fields (packaging, biomedical, textile, etc.). However, a significant economical effort is still directed in tailoring structural properties in order to further broaden the range of applications without impairing biodegradation. Improving the performance of biodegradable materials requires a good characterization of both physico-chemical and mechanical parameters. Polymer analysis can involve many different features including detailed characterization of chemical structures and compositions as well as average molecular mass determination. It is of outstanding importance in troubleshooting of a polymer manufacturing process and for quality control, especially in biomedical applications. This review describes recent trends in the structural characterization of biodegradable materials by modern mass spectrometry (MS). It provides an overview of the analytical tools used to evaluate their degradation. Several successful applications of MALDI-TOF MS (matrix assisted laser desorption ionization

Modern mass spectrometry in the characterization and degradation of biodegradable polymers

Energy Technology Data Exchange (ETDEWEB)

Rizzarelli, Paola, E-mail: paola.rizzarelli@cnr.it; Carroccio, Sabrina

2014-01-15

Graphical abstract: -- Highlights: •Recent trends in the structural characterization of biodegradable polymers by MALDI and ESI MS are discussed. •MALDI MS as a noteworthy tool to follow the synthetic polymerization route of biodegradable materials is evidenced. •Elucidation of degradation mechanisms by modern MS techniques is examined. •ESI MS and HPLC–ESI MS are highlighted as highly suitable methods for structural and quantitative analysis of water-soluble biodegradation products. •Novel MS methods developed ad hoc and new MALDI matrices for biodegradable polymers are reviewed. -- Abstract: In the last decades, the solid-waste management related to the extensively growing production of plastic materials, in concert with their durability, have stimulated increasing interest in biodegradable polymers. At present, a variety of biodegradable polymers has already been introduced onto the market and can now be competitive with non biodegradable thermoplastics in different fields (packaging, biomedical, textile, etc.). However, a significant economical effort is still directed in tailoring structural properties in order to further broaden the range of applications without impairing biodegradation. Improving the performance of biodegradable materials requires a good characterization of both physico-chemical and mechanical parameters. Polymer analysis can involve many different features including detailed characterization of chemical structures and compositions as well as average molecular mass determination. It is of outstanding importance in troubleshooting of a polymer manufacturing process and for quality control, especially in biomedical applications. This review describes recent trends in the structural characterization of biodegradable materials by modern mass spectrometry (MS). It provides an overview of the analytical tools used to evaluate their degradation. Several successful applications of MALDI-TOF MS (matrix assisted laser desorption ionization

Biodegradability of carbon nanotube/polymer nanocomposites under aerobic mixed culture conditions.

Science.gov (United States)

Phan, Duc C; Goodwin, David G; Frank, Benjamin P; Bouwer, Edward J; Fairbrother, D Howard

2018-10-15

The properties and commercial viability of biodegradable polymers can be significantly enhanced by the incorporation of carbon nanotubes (CNTs). The environmental impact and persistence of these carbon nanotube/polymer nanocomposites (CNT/PNCs) after disposal will be strongly influenced by their microbial interactions, including their biodegradation rates. At the end of consumer use, CNT/PNCs will encounter diverse communities of microorganisms in landfills, surface waters, and wastewater treatment plants. To explore CNT/PNC biodegradation under realistic environmental conditions, the effect of multi-wall CNT (MWCNT) incorporation on the biodegradation of polyhydroxyalkanoates (PHA) was investigated using a mixed culture of microorganisms from wastewater. Relative to unfilled PHA (0% w/w), the MWCNT loading (0.5-10% w/w) had no statistically significant effect on the rate of PHA matrix biodegradation. Independent of the MWCNT loading, the extent of CNT/PNC mass remaining closely corresponded to the initial mass of CNTs in the matrix suggesting a lack of CNT release. CNT/PNC biodegradation was complete in approximately 20 days and resulted in the formation of a compressed CNT mat that retained the shape of the initial CNT/PNC. This study suggests that although CNTs have been shown to be cytotoxic towards a range of different microorganisms, this does not necessarily impact the biodegradation of the surrounding polymer matrix in mixed culture, particularly in situations where the polymer type and/or microbial population favor rapid polymer biodegradation. Copyright © 2018 Elsevier B.V. All rights reserved.

Nanomembranes and Nanofibers from Biodegradable Conducting Polymers

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Jordi Puiggalí

2013-09-01

Full Text Available This review provides a current status report of the field concerning preparation of fibrous mats based on biodegradable (e.g., aliphatic polyesters such as polylactide or polycaprolactone and conducting polymers (e.g., polyaniline, polypirrole or polythiophenes. These materials have potential biomedical applications (e.g., tissue engineering or drug delivery systems and can be combined to get free-standing nanomembranes and nanofibers that retain the better properties of their corresponding individual components. Systems based on biodegradable and conducting polymers constitute nowadays one of the most promising solutions to develop advanced materials enable to cover aspects like local stimulation of desired tissue, time controlled drug release and stimulation of either the proliferation or differentiation of various cell types. The first sections of the review are focused on a general overview of conducting and biodegradable polymers most usually employed and the explanation of the most suitable techniques for preparing nanofibers and nanomembranes (i.e., electrospinning and spin coating. Following sections are organized according to the base conducting polymer (e.g., Sections 4–6 describe hybrid systems having aniline, pyrrole and thiophene units, respectively. Each one of these sections includes specific subsections dealing with applications in a nanofiber or nanomembrane form. Finally, miscellaneous systems and concluding remarks are given in the two last sections.

Engineered biosynthesis of biodegradable polymers.

Science.gov (United States)

Jambunathan, Pooja; Zhang, Kechun

2016-08-01

Advances in science and technology have resulted in the rapid development of biobased plastics and the major drivers for this expansion are rising environmental concerns of plastic pollution and the depletion of fossil-fuels. This paper presents a broad view on the recent developments of three promising biobased plastics, polylactic acid (PLA), polyhydroxyalkanoate (PHA) and polybutylene succinate (PBS), well known for their biodegradability. The article discusses the natural and recombinant host organisms used for fermentative production of monomers, alternative carbon feedstocks that have been used to lower production cost, different metabolic engineering strategies used to improve product titers, various fermentation technologies employed to increase productivities and finally, the different downstream processes used for recovery and purification of the monomers and polymers.

Modern mass spectrometry in the characterization and degradation of biodegradable polymers.

Science.gov (United States)

Rizzarelli, Paola; Carroccio, Sabrina

2014-01-15

In the last decades, the solid-waste management related to the extensively growing production of plastic materials, in concert with their durability, have stimulated increasing interest in biodegradable polymers. At present, a variety of biodegradable polymers has already been introduced onto the market and can now be competitive with non biodegradable thermoplastics in different fields (packaging, biomedical, textile, etc.). However, a significant economical effort is still directed in tailoring structural properties in order to further broaden the range of applications without impairing biodegradation. Improving the performance of biodegradable materials requires a good characterization of both physico-chemical and mechanical parameters. Polymer analysis can involve many different features including detailed characterization of chemical structures and compositions as well as average molecular mass determination. It is of outstanding importance in troubleshooting of a polymer manufacturing process and for quality control, especially in biomedical applications. This review describes recent trends in the structural characterization of biodegradable materials by modern mass spectrometry (MS). It provides an overview of the analytical tools used to evaluate their degradation. Several successful applications of MALDI-TOF MS (matrix assisted laser desorption ionization time of flight) and ESI MS (electrospray mass spectrometry) for the determination of the structural architecture of biodegradable macromolecules, including their topology, composition, chemical structure of the end groups have been reported. However, MS methodologies have been recently applied to evaluate the biodegradation of polymeric materials. ESI MS represents the most useful technique for characterizing water-soluble polymers possessing different end group structures, with the advantage of being easily interfaced with solution-based separation techniques such as high-performance liquid

An overview of natural polymers for oral insulin delivery.

Science.gov (United States)

Sonia, T A; Sharma, Chandra P

2012-07-01

Current therapy for diabetes mellitus through oral anti-diabetic drugs and subcutaneous administration of insulin suffers from serious disadvantages, such as patient noncompliance and occasional hypoglycemia. Moreover, these approaches doesn't mimic the normal physiological pattern of insulin release. Oral route would be the most convenient and preferred route if it is available. Polymeric nano and/or microparticles, either natural or synthetic have been used as matrices for oral insulin delivery. Natural polymers are of particular interest due to their nontoxic, biocompatible, biodegradable and hydrophilic nature. Among the natural polymers used for oral insulin delivery, chitosan (CS) is widely explored owing to its ease of chemical modification and favorable biological properties. In addition, many advantages such as safety, biodegradability, widespread availability and low cost justify the continuing development of promising insulin delivery system based on CS. Copyright © 2012 Elsevier Ltd. All rights reserved.

Methods for Evaluating the Biodegradability of Environmentally Degradable Polymers

NARCIS (Netherlands)

Zee, van der M.

2014-01-01

This chapter presents an overview of the current knowledge on experimental methods for monitoring the biodegradability of polymeric materials. The focus is, in particular, on the biodegradation of materials under environmental conditions. Examples of in vivo degradation of polymers used in

Absorbable and biodegradable polymers

CERN Document Server

Shalaby, Shalaby W

2003-01-01

INTRODUCTION NOTES: Absorbable/Biodegradable Polymers: Technology Evolution. DEVELOPMENT AND APPLICATIONOF NEW SYSTEMS: Segmented Copolyesters with Prolonged Strength Retention Profiles. Polyaxial Crystalline Fiber-Forming Copolyester. Polyethylene Glycol-Based Copolyesters. Cyanoacrylate-Based Systems as Tissue Adhesives. Chitosan-Based Systems. Hyaluronic Acid-Based Systems. DEVELOPMENTS IN PREPARATIVE, PROCESSING, AND EVALUATION METHODS: New Approaches to the Synthesis of Crystalline. Fiber-Forming Aliphatic Copolyesters. Advances in Morphological Development to Tailor the Performance of Me

Biodegradation Study of Nanocomposites of Phenol Novolac Epoxy/Unsaturated Polyester Resin/Egg Shell Nanoparticles Using Natural Polymers

Directory of Open Access Journals (Sweden)

S. M. Mousavi

2015-01-01

Full Text Available Nanocomposite materials refer to those materials whose reinforcing phase has dimensions on a scale from one to one hundred nanometers. In this study, the nanocomposite biodegradation of the phenol Novolac epoxy and the unsaturated polyester resins was investigated using the egg shell nanoparticle as bioceramic as well as starch and glycerin as natural polymers to modify their properties. The phenol Novolac epoxy resin has a good compatibility with the unsaturated polyester resin. The prepared samples with different composition of materials for specified time were buried under soil and their biodegradation was studied using FTIR and SEM. The FTIR results before and after degradation showed that the presence of the hydroxyl group increased the samples degradation. Also adding the egg shell nanoparticle to samples had a positive effect on its degradation. The SEM results with and without the egg shell nanoparticle also showed that use of the egg shell nanoparticle increases the samples degradation. Additionally, increasing the amount of starch, and glycerol and the presence of egg shell nanoparticles can increase water adsorption.

Radiation processing of natural polymers: The IAEA contribution

Science.gov (United States)

Haji-Saeid, Mohammad; Safrany, Agnes; Sampa, Maria Helena de O.; Ramamoorthy, Natesan

2010-03-01

Radiation processing offers a clean and additive-free method for preparation of value-added novel materials based on renewable, non-toxic, and biodegradable natural polymers. Crosslinked natural polymers can be used as hydrogel wound dressings, face cleaning cosmetic masks, adsorbents of toxins, and non-bedsore mats; while low molecular weight products show antibiotic, antioxidant, and plant-growth promoting properties. Recognizing the potential benefits that radiation technology can offer for processing of natural polymers into useful products, the IAEA implemented a coordinated research project (CRP) on "Development of Radiation-processed products of Natural Polymers for application in Agriculture, Healthcare, Industry and Environment". This CRP was launched at the end of 2007 with participation of 16 MS to help connecting radiation technology and end-users to derive enhanced benefits from these new value-added products of radiation-processed natural materials. In this paper the results of activities in participating MS related to this work will be presented.

Radiation processing of natural polymers: The IAEA contribution

International Nuclear Information System (INIS)

Haji-Saeid, Mohammad; Safrany, Agnes; Sampa, Maria Helena de O.; Ramamoorthy, Natesan

2010-01-01

Radiation processing offers a clean and additive-free method for preparation of value-added novel materials based on renewable, non-toxic, and biodegradable natural polymers. Crosslinked natural polymers can be used as hydrogel wound dressings, face cleaning cosmetic masks, adsorbents of toxins, and non-bedsore mats; while low molecular weight products show antibiotic, antioxidant, and plant-growth promoting properties. Recognizing the potential benefits that radiation technology can offer for processing of natural polymers into useful products, the IAEA implemented a coordinated research project (CRP) on 'Development of Radiation-processed products of Natural Polymers for application in Agriculture, Healthcare, Industry and Environment'. This CRP was launched at the end of 2007 with participation of 16 MS to help connecting radiation technology and end-users to derive enhanced benefits from these new value-added products of radiation-processed natural materials. In this paper the results of activities in participating MS related to this work will be presented.

Biodegradable Polymers Induce CD54 on THP-1 Cells in Skin Sensitization Test.

Science.gov (United States)

Jung, Yeon Suk; Kato, Reiko; Tsuchiya, Toshie

2011-01-01

Currently, nonanimal methods of skin sensitization testing for various chemicals, biodegradable polymers, and biomaterials are being developed in the hope of eliminating the use of animals. The human cell line activation test (h-CLAT) is a skin sensitization assessment that mimics the functions of dendritic cells (DCs). DCs are specialized antigen-presenting cells, and they interact with T cells and B cells to initiate immune responses. Phenotypic changes in DCs, such as the production of CD86 and CD54 and internalization of MHC class II molecules, have become focal points of the skin sensitization test. In this study, we used h-CLAT to assess the effects of biodegradable polymers. The results showed that several biodegradable polymers increased the expression of CD54, and the relative skin sensitizing abilities of biodegradable polymers were PLLG (75 : 25) < PLLC (40 : 60) < PLGA (50 : 50) < PCG (50 : 50). These results may contribute to the creation of new guidelines for the use of biodegradable polymers in scaffolds or allergenic hazards.

Biodegradable Polymers Induce CD54 on THP-1 Cells in Skin Sensitization Test

Directory of Open Access Journals (Sweden)

Yeon Suk Jung

2011-01-01

Full Text Available Currently, nonanimal methods of skin sensitization testing for various chemicals, biodegradable polymers, and biomaterials are being developed in the hope of eliminating the use of animals. The human cell line activation test (h-CLAT is a skin sensitization assessment that mimics the functions of dendritic cells (DCs. DCs are specialized antigen-presenting cells, and they interact with T cells and B cells to initiate immune responses. Phenotypic changes in DCs, such as the production of CD86 and CD54 and internalization of MHC class II molecules, have become focal points of the skin sensitization test. In this study, we used h-CLAT to assess the effects of biodegradable polymers. The results showed that several biodegradable polymers increased the expression of CD54, and the relative skin sensitizing abilities of biodegradable polymers were PLLG (75 : 25 < PLLC (40 : 60 < PLGA (50 : 50 < PCG (50 : 50. These results may contribute to the creation of new guidelines for the use of biodegradable polymers in scaffolds or allergenic hazards.

Sago Starch-Mixed Low-Density Polyethylene Biodegradable Polymer: Synthesis and Characterization

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Md Enamul Hoque

2013-01-01

Full Text Available This research focuses on synthesis and characterization of sago starch-mixed LDPE biodegradable polymer. Firstly, the effect of variation of starch content on mechanical property (elongation at break and Young’s modulus and biodegradability of the polymer was studied. The LDPE was combined with 10%, 30%, 50%, and 70% of sago for this study. Then how the cross-linking with trimethylolpropane triacrylate (TMPTA and electron beam (EB irradiation influence the mechanical and thermal properties of the polymer was investigated. In the 2nd study, to avoid overwhelming of data LDPE polymer was incorporated with only 50% of starch. The starch content had direct influence on mechanical property and biodegradability of the polymer. The elongation at break decreased with increase of starch content, while Young’s modulus and mass loss (i.e., degradation were found to increase with increase of starch content. Increase of cross-linker (TMPTA and EB doses also resulted in increased Young’s modulus of the polymer. However, both cross-linking and EB irradiation processes rendered lowering of polymer’s melting temperature. In conclusion, starch content and modification processes play significant roles in controlling mechanical, thermal, and degradation properties of the starch-mixed LDPE synthetic polymer, thus providing the opportunity to modulate the polymer properties for tailored applications.

Biodegradation of bioplastics in natural environments.

Science.gov (United States)

Emadian, S Mehdi; Onay, Turgut T; Demirel, Burak

2017-01-01

The extensive production of conventional plastics and their use in different commercial applications poses a significant threat to both the fossil fuels sources and the environment. Alternatives called bioplastics evolved during development of renewable resources. Utilizing renewable resources like agricultural wastes (instead of petroleum sources) and their biodegradability in different environments enabled these polymers to be more easily acceptable than the conventional plastics. The biodegradability of bioplastics is highly affected by their physical and chemical structure. On the other hand, the environment in which they are located, plays a crucial role in their biodegradation. This review highlights the recent findings attributed to the biodegradation of bioplastics in various environments, environmental conditions, degree of biodegradation, including the identified bioplastic-degrading microorganisms from different microbial communities. Copyright © 2016 Elsevier Ltd. All rights reserved.

Biodegradation of partially hydrolyzed polyacrylamide by bacteria isolated from production water after polymer flooding in an oil field

International Nuclear Information System (INIS)

Bao Mutai; Chen Qingguo; Li Yiming; Jiang Guancheng

2010-01-01

Partially hydrolyzed polyacrylamide (HPAM) in production water after polymer flooding in oil filed causes environmental problems, such as increases the difficulty in oil-water separation, degrades naturally to produce toxic acrylamide and endanger local ecosystem. Biodegradation of HPAM may be an efficient way to solve these problems. The biodegradability of HPAM in an aerobic environment was studied. Two HPAM-degrading bacterial strains, named PM-2 and PM-3, were isolated from the produced water of polymer flooding. They were subsequently identified as Bacillus cereus and Bacillus sp., respectively. The utilization of HPAM by the two strains was explored. The amide group of HPAM could serve as a nitrogen source for the two microorganisms, the carbon backbone of these polymers could be partly utilized by microorganisms. The HPAM samples before and after bacterial biodegradation were analyzed by the infrared spectrum, high performance liquid chromatography and scanning electronic microscope. The results indicated that the amide group of HPAM in the biodegradation products had been converted to a carboxyl group, and no acrylamide monomer was found. The HPAM carbon backbone was metabolized by the bacteria during the course of its growth. Further more, the hypothesis about the biodegradation of HPAM in aerobic bacterial culture is proposed.

Biodegradable-Polymer Biolimus-Eluting Stents versus Durable-Polymer Everolimus-Eluting Stents at One-Year Follow-Up: A Registry-Based Cohort Study.

Science.gov (United States)

Parsa, Ehsan; Saroukhani, Sepideh; Majlessi, Fereshteh; Poorhosseini, Hamidreza; Lofti-Tokaldany, Masoumeh; Jalali, Arash; Salarifar, Mojtaba; Nematipour, Ebrahim; Alidoosti, Mohammad; Aghajani, Hassan; Amirzadegan, Alireza; Kassaian, Seyed Ebrahim

2016-04-01

We compared outcomes of percutaneous coronary intervention patients who received biodegradable-polymer biolimus-eluting stents with those who received durable-polymer everolimus-eluting stents. At Tehran Heart Center, we performed a retrospective analysis of the data from January 2007 through December 2011 on 3,270 consecutive patients with coronary artery disease who underwent percutaneous coronary intervention with the biodegradable-polymer biolimus-eluting stent or the durable-polymer everolimus-eluting stent. We excluded patients with histories of coronary artery bypass grafting or percutaneous coronary intervention, acute ST-segment-elevation myocardial infarction, or the implantation of 2 different stent types. Patients were monitored for 12 months. The primary endpoint was a major adverse cardiac event, defined as a composite of death, nonfatal myocardial infarction, and target-vessel and target-lesion revascularization. Durable-polymer everolimus-eluting stents were implanted in 2,648 (81%) and biodegradable-polymer biolimus-eluting stents in 622 (19%) of the study population. There was no significant difference between the 2 groups (2.7% vs 2.7%; P=0.984) in the incidence of major adverse cardiac events. The cumulative adjusted probability of major adverse cardiac events in the biodegradable-polymer biolimus-eluting stent group did not differ from that of such events in the durable-polymer everolimus-eluting stent group (hazard ratio=0.768; 95% confidence interval, 0.421-1.44; P=0.388). We conclude that in our patients the biodegradable-polymer biolimus-eluting stent was as effective and safe, during the 12-month follow-up period, as was the durable-polymer everolimus-eluting stent.

Radiation processing of biodegradable polymer hydrogel from cellulose derivatives

International Nuclear Information System (INIS)

Wach, Radoslaw A.; Mitomo, Hiroshi; Yoshii, Fumio; Kume, Tamikazu

2001-01-01

The effects of high-energy radiation on ethers of cellulose: carboxymethyl-, hydroxypropyl- and hydroxyethylcellulose have been investigated. Polymers were irradiated in solid state and aqueous solution at various concentrations. Degree of substitution (DS), the concentration in the solution and irradiation conditions had a significant impact on the obtained products. Irradiation of polymers in solid and in diluted solution resulted in their degradation. A novel hydrogels of such natural polymers were synthesized, without using any additives, by irradiation at high concentration. It was found that high DS of CMC promoted crosslinking and, for all of the ethers, the gel formation occurred easier for more concentrated solutions. Paste-like form of the initial material, when water plasticised the bulk of polymer mass, along with the high dose rate and preventing oxygen accessibility to the sample during irradiation were favorable for hydrogel preparation. Up to 95% of gel fraction was obtained from 50 and 60% CMC solutions irradiated by gamma rays or by a beam of accelerated electrons (EB). The other polymers were more sensitive to the dose rate and formed gels with higher gel fraction while processed by EB. Moreover, polymers (except CMC) treated by gamma rays were susceptible to degradation after application of a dose over 50-100 kGy. The presence of oxygen in the system during irradiation limited a gel content and was prone to easier degradation of already formed gel. Produced hydrogels swelled markedly by absorption when paced in the solvent. Crosslinked polymers showed susceptibility to degradation by cellulase enzyme and by the action of microorganisms in compost or under natural conditions in soil thus could be included into the group of biodegradable materials. (author)

Radiation processing of biodegradable polymer hydrogel from cellulose derivatives

Energy Technology Data Exchange (ETDEWEB)

Wach, Radoslaw A.; Mitomo, Hiroshi [Gunma Univ., Faculty of Engineering, Department of Biological and Chemical Engineering, Kiryu, Gunma (Japan); Yoshii, Fumio; Kume, Tamikazu [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment

2001-03-01

The effects of high-energy radiation on ethers of cellulose: carboxymethyl-, hydroxypropyl- and hydroxyethylcellulose have been investigated. Polymers were irradiated in solid state and aqueous solution at various concentrations. Degree of substitution (DS), the concentration in the solution and irradiation conditions had a significant impact on the obtained products. Irradiation of polymers in solid and in diluted solution resulted in their degradation. A novel hydrogels of such natural polymers were synthesized, without using any additives, by irradiation at high concentration. It was found that high DS of CMC promoted crosslinking and, for all of the ethers, the gel formation occurred easier for more concentrated solutions. Paste-like form of the initial material, when water plasticised the bulk of polymer mass, along with the high dose rate and preventing oxygen accessibility to the sample during irradiation were favorable for hydrogel preparation. Up to 95% of gel fraction was obtained from 50 and 60% CMC solutions irradiated by gamma rays or by a beam of accelerated electrons (EB). The other polymers were more sensitive to the dose rate and formed gels with higher gel fraction while processed by EB. Moreover, polymers (except CMC) treated by gamma rays were susceptible to degradation after application of a dose over 50-100 kGy. The presence of oxygen in the system during irradiation limited a gel content and was prone to easier degradation of already formed gel. Produced hydrogels swelled markedly by absorption when paced in the solvent. Crosslinked polymers showed susceptibility to degradation by cellulase enzyme and by the action of microorganisms in compost or under natural conditions in soil thus could be included into the group of biodegradable materials. (author)

Synthesis, properties and applications of biodegradable polymers derived from diols and dicarboxylic acids: from polyesters to poly(ester amide)s.

Science.gov (United States)

Díaz, Angélica; Katsarava, Ramaz; Puiggalí, Jordi

2014-04-25

Poly(alkylene dicarboxylate)s constitute a family of biodegradable polymers with increasing interest for both commodity and speciality applications. Most of these polymers can be prepared from biobased diols and dicarboxylic acids such as 1,4-butanediol, succinic acid and carbohydrates. This review provides a current status report concerning synthesis, biodegradation and applications of a series of polymers that cover a wide range of properties, namely, materials from elastomeric to rigid characteristics that are suitable for applications such as hydrogels, soft tissue engineering, drug delivery systems and liquid crystals. Finally, the incorporation of aromatic units and α-amino acids is considered since stiffness of molecular chains and intermolecular interactions can be drastically changed. In fact, poly(ester amide)s derived from naturally occurring amino acids offer great possibilities as biodegradable materials for biomedical applications which are also extensively discussed.

Biodegradable Polymer Biolimus-Eluting Stents Versus Durable Polymer Everolimus-Eluting Stents in Patients With Coronary Artery Disease: Final 5-Year Report From the COMPARE II Trial (Abluminal Biodegradable Polymer Biolimus-Eluting Stent Versus Durable Polymer Everolimus-Eluting Stent).

Science.gov (United States)

Vlachojannis, Georgios J; Smits, Pieter C; Hofma, Sjoerd H; Togni, Mario; Vázquez, Nicolás; Valdés, Mariano; Voudris, Vassilis; Slagboom, Ton; Goy, Jean-Jaques; den Heijer, Peter; van der Ent, Martin

2017-06-26

This analysis investigates the 5-year outcomes of the biodegradable polymer biolimus-eluting stent (BP-BES) and durable polymer everolimus-eluting stent (DP-EES) in an all-comers population undergoing percutaneous coronary intervention. Recent 1- and 3-year results from randomized trials have indicated similar safety and efficacy outcomes of BP-BES and DP-EES. Whether benefits of the biodegradable polymer device arise over longer follow-up is unknown. Moreover, in-depth, prospective, long-term follow-up data on metallic drug-eluting stents with durable or biodegradable polymers are scarce. The COMPARE II trial (Abluminal Biodegradable Polymer Biolimus-Eluting Stent Versus Durable Polymer Everolimus-Eluting Stent) was a prospective, randomized, multicenter, all-comers trial in which 2,707 patients were randomly allocated (2:1) to BP-BES or DP-EES. The pre-specified endpoint at 5 years was major adverse cardiac events, a composite of cardiac death, nonfatal myocardial infarction, or target vessel revascularization. Five-year follow-up was available in 2,657 patients (98%). At 5 years, major adverse cardiac events occurred in 310 patients (17.3%) in the BP-BES group and 142 patients (15.6%) in the DP-EES group (p = 0.26). The rate of the combined safety endpoint all-cause death or myocardial infarction was 15.0% in the BP-BES group versus 14.8% in the DP-EES group (p = 0.90), whereas the efficacy measure target vessel revascularization was 10.6% versus 9.0% (p = 0.18), respectively. Interestingly, definite stent thrombosis rates did not differ between groups (1.5% for BP-BES vs. 0.9% for DP-EES; p = 0.17). The 5-year analysis comparing biodegradable polymer-coated BES and the durable polymer-coated EES confirms the initial early- and mid-term results regarding similar safety and efficacy outcomes in this all-comers percutaneous coronary intervention population. Copyright © 2017 American College of Cardiology Foundation. Published by Elsevier Inc. All rights

Current knowledge on biodegradable microspheres in drug delivery.

Science.gov (United States)

Prajapati, Vipul D; Jani, Girish K; Kapadia, Jinita R

2015-08-01

Biodegradable microspheres have gained popularity for delivering a wide variety of molecules via various routes. These types of products have been prepared using various natural and synthetic biodegradable polymers through suitable techniques for desired delivery of various challenging molecules. Selection of biodegradable polymers and technique play a key role in desired drug delivery. This review describes an overview of the fundamental knowledge and status of biodegradable microspheres in effective delivery of various molecules via desired routes with consideration of outlines of various compendial and non-compendial biodegradable polymers, formulation techniques and release mechanism of microspheres, patents and commercial biodegradable microspheres. There are various advantages of using biodegradable polymers including promise of development with different types of molecules. Biocompatibility, low dosage and reduced side effects are some reasons why usage biodegradable microspheres have gained in popularity. Selection of biodegradable polymers and formulation techniques to create microspheres is the biggest challenge in research. In the near future, biodegradable microspheres will become the eco-friendly product for drug delivery of various genes, hormones, proteins and peptides at specific site of body for desired periods of time.

Biolimus-eluting biodegradable polymer-coated stent versus durable polymer-coated sirolimus-eluting stent in unselected patients receiving percutaneous coronary intervention (SORT OUT V)

DEFF Research Database (Denmark)

Christiansen, Evald Høj; Jensen, Lisette Okkels; Thayssen, Per

2013-01-01

Third-generation biodegradable polymer drug-eluting stents might reduce the risk of stent thrombosis compared with first-generation permanent polymer drug-eluting stents. We aimed to further investigate the effects of a biodegradable polymer biolimus-eluting stent compared with a durable polymer......-coated sirolimus-eluting stent in a population-based setting....

The second green revolution? Production of plant-based biodegradable plastics.

Science.gov (United States)

Mooney, Brian P

2009-03-01

Biodegradable plastics are those that can be completely degraded in landfills, composters or sewage treatment plants by the action of naturally occurring micro-organisms. Truly biodegradable plastics leave no toxic, visible or distinguishable residues following degradation. Their biodegradability contrasts sharply with most petroleum-based plastics, which are essentially indestructible in a biological context. Because of the ubiquitous use of petroleum-based plastics, their persistence in the environment and their fossil-fuel derivation, alternatives to these traditional plastics are being explored. Issues surrounding waste management of traditional and biodegradable polymers are discussed in the context of reducing environmental pressures and carbon footprints. The main thrust of the present review addresses the development of plant-based biodegradable polymers. Plants naturally produce numerous polymers, including rubber, starch, cellulose and storage proteins, all of which have been exploited for biodegradable plastic production. Bacterial bioreactors fed with renewable resources from plants--so-called 'white biotechnology'--have also been successful in producing biodegradable polymers. In addition to these methods of exploiting plant materials for biodegradable polymer production, the present review also addresses the advances in synthesizing novel polymers within transgenic plants, especially those in the polyhydroxyalkanoate class. Although there is a stigma associated with transgenic plants, especially food crops, plant-based biodegradable polymers, produced as value-added co-products, or, from marginal land (non-food), crops such as switchgrass (Panicum virgatum L.), have the potential to become viable alternatives to petroleum-based plastics and an environmentally benign and carbon-neutral source of polymers.

Experimental degradation of polymer shopping bags (standard and degradable plastic, and biodegradable) in the gastrointestinal fluids of sea turtles.

Science.gov (United States)

Müller, Christin; Townsend, Kathy; Matschullat, Jörg

2012-02-01

The persistence of marine debris such as discarded polymer bags has become globally an increasing hazard to marine life. To date, over 177 marine species have been recorded to ingest man-made polymers that cause life-threatening complications such as gut impaction and perforation. This study set out to test the decay characteristics of three common types of shopping bag polymers in sea turtle gastrointestinal fluids (GIF): standard and degradable plastic, and biodegradable. Fluids were obtained from the stomachs, small intestines and large intestines of a freshly dead Green turtle (Chelonia mydas) and a Loggerhead turtle (Caretta caretta). Controls were carried out with salt and freshwater. The degradation rate was measured over 49 days, based on mass loss. Degradation rates of the standard and the degradable plastic bags after 49 days across all treatments and controls were negligible. The biodegradable bags showed mass losses between 3 and 9%. This was a much slower rate than reported by the manufacturers in an industrial composting situation (100% in 49 days). The GIF of the herbivorous Green turtle showed an increased capacity to break down the biodegradable polymer relative to the carnivorous Loggerhead, but at a much lower rate than digestion of natural vegetative matter. While the breakdown rate of biodegradable polymers in the intestinal fluids of sea turtles is greater than standard and degradable plastics, it is proposed that this is not rapid enough to prevent morbidity. Further study is recommended to investigate the speed at which biodegradable polymers decompose outside of industrial composting situations, and their durability in marine and freshwater systems. Copyright © 2011 Elsevier B.V. All rights reserved.

Mass spectrometry for the elucidation of the subtle molecular structure of biodegradable polymers and their degradation products.

Science.gov (United States)

Kowalczuk, Marek; Adamus, Grażyna

2016-01-01

Contemporary reports by Polish authors on the application of mass spectrometric methods for the elucidation of the subtle molecular structure of biodegradable polymers and their degradation products will be presented. Special emphasis will be given to natural aliphatic (co)polyesters (PHA) and their synthetic analogues, formed through anionic ring-opening polymerization (ROP) of β-substituted β-lactones. Moreover, the application of MS techniques for the evaluation of the structure of biodegradable polymers obtained in ionic and coordination polymerization of cyclic ethers and esters as well as products of step-growth polymerization, in which bifunctional or multifunctional monomers react to form oligomers and eventually long chain polymers, will be discussed. Furthermore, the application of modern MS techniques for the assessment of polymer degradation products, frequently bearing characteristic end groups that can be revealed and differentiated by MS, will be discussed within the context of specific degradation pathways. Finally, recent Polish accomplishments in the area of mass spectrometry will be outlined. © 2015 Wiley Periodicals, Inc.

Biodegradable polymer nanocomposites based on natural nanotubes: effect of magnetically modified halloysite on the behaviour of polycaprolactone

Czech Academy of Sciences Publication Activity Database

Khunová, V.; Šafařík, Ivo; Škrátek, M.; Kelnar, Ivan; Tomanová, K.

2016-01-01

Roč. 51, č. 3 (2016), s. 435-444 ISSN 0009-8558 R&D Projects: GA ČR(CZ) GA13-15255S Institutional support: RVO:60077344 ; RVO:61389013 Keywords : magnetically modified HNTs * biodegradable polymer nanocomposites * polycaprolactone Subject RIV: CD - Macromolecular Chemistry ; JI - Composite Materials (UMCH-V) Impact factor: 1.052, year: 2016

Progress in R and D radiation processing of natural polymers in the Philippines

International Nuclear Information System (INIS)

Dela Rosa, A.; Abad, L.; Relleve, L.; Aranilla, C.; Cabalfin, E.; Bisnar, C.

2007-01-01

Radiation technology has emerged as an environment-friendly, commercially viable technology with broad applications that can essentially contribute to achieve the goal of sustainable development. Natural polymers are good raw materials since they are biodegradable, readily available in large quantity and at low cost. Radiation processing of natural polymers is a potential area to widen the prospect of industrial scale application of radiation technology in the Philippines. (author)

Biodegradation of New Polymer Foundry Binders for the Example of the Composition Polyacrylic Acid/Starch

Directory of Open Access Journals (Sweden)

Beata Grabowska

2011-04-01

Full Text Available The investigations on the biodegradation process pathway of the new polymer binders for the example of water soluble compositionpolyacrylic acid/starch are presented in the hereby paper. Degradation was carried out in water environment and in a soil. Thedetermination of the total oxidation biodegradation in water environment was performed under laboratory conditions in accordance with the static water test system (Zahn-Wellens method, in which the mixture undergoing biodecomposition contained inorganic nutrient,activated sludge and the polymer composition, as the only carbon and energy source. The biodecomposition progress of the polymercomposition sample in water environment was estimated on the basis of the chemical oxygen demand (COD measurements and thedetermination the biodegradation degree, Rt, during the test. These investigations indicated that the composition polyacrylic acid/starchconstitutes the fully biodegradable material in water environment. The biodegradation degree Rt determined in the last 29th day of the test duration achieved 65%, which means that the investigated polymer composition can be considered to be fully biodegradable.During the 6 months biodegradation process of the cross-linked sample of the polymer composition in a garden soil several analysis ofsurface and structural changes, resulting from the sample decomposition, were performed. Those were: thermal analyses (TG-DSC,structural analyses (Raman spectroscopy and microscopic analyses (optical microscopy, AFM.

Physical, mechanical, and biodegradable properties of meranti wood polymer composites

International Nuclear Information System (INIS)

Enamul Hoque, M.; Aminudin, M.A.M.; Jawaid, M.; Islam, M.S.; Saba, N.; Paridah, M.T.

2014-01-01

Highlights: • In-situ polymerization and solution casting method used to manufacture WPC. • In-situ WPC exhibited better properties compared to pure wood, 5% WPC and 20% WPC. • Lowest water absorption and least biodegradability shown by In-situ wood. - Abstract: In-situ polymerization and solution casting techniques are two effective methods to manufacture wood polymer composites (WPCs). In this study, wood polymer composites (WPCs) were manufactured from meranti sapwood by solution casting and in-situ polymerization process using methyl methacrylate (MMA) and epoxy matrix respectively. Physical, mechanical, and morphological characterizations of fabricated WPCs were then carried out to analyse their properties. Morphological properties of composites samples were analyzed through scanning electron microscopy (SEM). The result reveals that in-situ wood composite exhibited better properties compared to pure wood, 5% WPC and 20% WPC. Moreover, in-situ WPC had lowest water absorption and least biodegraded. Conversely, pure wood shown moderate mechanical strength, high biodegradation and water absorption rate. In term of biodegradation, earth-medium brought more severe effect than water in deteriorating the properties of the specimens

Polyester-Based (Bio)degradable Polymers as Environmentally Friendly Materials for Sustainable Development

Science.gov (United States)

Rydz, Joanna; Sikorska, Wanda; Kyulavska, Mariya; Christova, Darinka

2014-01-01

This review focuses on the polyesters such as polylactide and polyhydroxyalkonoates, as well as polyamides produced from renewable resources, which are currently among the most promising (bio)degradable polymers. Synthetic pathways, favourable properties and utilisation (most important applications) of these attractive polymer families are outlined. Environmental impact and in particular (bio)degradation of aliphatic polyesters, polyamides and related copolymer structures are described in view of the potential applications in various fields. PMID:25551604

Electrospun biodegradable polymers loaded with bactericide agents

Directory of Open Access Journals (Sweden)

Ramaz Katsarava

2016-03-01

Full Text Available Development of materials with an antimicrobial activity is fundamental for different sectors, including medicine and health care, water and air treatment, and food packaging. Electrospinning is a versatile and economic technique that allows the incorporation of different natural, industrial, and clinical agents into a wide variety of polymers and blends in the form of micro/nanofibers. Furthermore, the technique is versatile since different constructs (e.g. those derived from single electrospinning, co-electrospinning, coaxial electrospinning, and miniemulsion electrospinning can be obtained to influence the ability to load agents with different characteristics and stability and to modify the release behaviour. Furthermore, antimicrobial agents can be loaded during the electrospinning process or by a subsequent coating process. In order to the mitigate burst release effect, it is possible to encapsulate the selected drug into inorganic nanotubes and nanoparticles, as well as in organic cyclodextrine polysaccharides. In the same way, processes that involve covalent linkage of bactericide agents during surface treatment of electrospun samples may also be considered. The present review is focused on more recent works concerning the electrospinning of antimicrobial polymers. These include chitosan and common biodegradable polymers with activity caused by the specific load of agents such as metal and metal oxide particles, quaternary ammonium compounds, hydantoin compounds, antibiotics, common organic bactericides, and bacteriophages.

The Recent Developments in Biobased Polymers toward General and Engineering Applications : Polymers that Are Upgraded from Biodegradable Polymers, Analogous to Petroleum-Derived Polymers, and Newly Developed

NARCIS (Netherlands)

Nakajima, Hajime; Dijkstra, Peter; Loos, Katja

2017-01-01

The main motivation for development of biobased polymers was their biodegradability, which is becoming important due to strong public concern about waste. Reflecting recent changes in the polymer industry, the sustainability of biobased polymers allows them to be used for general and engineering

Control of colloidal CaCO3 suspension by using biodegradable polymers during fabrication

Directory of Open Access Journals (Sweden)

Nemany Abdelhamid Nemany Hanafy

2015-03-01

The aim of this work was to investigate the synthesis process of CaCO3 particles in different experimental conditions: calcium carbonate was produced in presence and in absence of water and with addition of appropriate polymers. In particular, chitosan (CHI and poly acrylic acid (PAA were chosen as biodegradable polymers whereas PSS and PAH were chosen as non-biodegradable polymers. Shape and diameter of particles were investigated by using transmission and scanning electron microscopy, elemental composition was inferred by energy dispersive X-ray analyses whereas their charges were explored by using zeta potential.

Transferring the Selectivity of a Natural Antibody into a Molecularly Imprinted Polymer

NARCIS (Netherlands)

Schirhagl, Romana

2017-01-01

Natural antibodies are widely used for their unprecedented reproducibility and the remarkable selectivity for a wide range of analytes. However, biodegradability and the need to work in biocompatible environments limit their applications. Molecularly imprinted polymers are a robust alternative.

A novel bio-degradable polymer stabilized Ag/TiO2 nanocomposites and their catalytic activity on reduction of methylene blue under natural sun light.

Science.gov (United States)

Geetha, D; Kavitha, S; Ramesh, P S

2015-11-01

In the present work we defined a novel method of TiO2 doped silver nanocomposite synthesis and stabilization using bio-degradable polymers viz., chitosan (Cts) and polyethylene glycol (PEG). These polymers are used as reducing agents. The instant formation of AgNPs was analyzed by visual observation and UV-visible spectrophotometer. TiO2 nanoparticles doped at different concentrations viz., 0.03, 0.06 and 0.09mM on PEG/Cts stabilized silver (0.04wt%) were successfully synthesized. This study presents a simple route for the in situ synthesis of both metal and polymer confined within the nanomaterial, producing ternary hybrid inorganic-organic nanomaterials. The results reveal that they have higher photocatalytic efficiencies under natural sun light. The synthesized TiO2 doped Ag nanocomposites (NCs) were characterized by SEM/EDS, TEM, XRD, FTIR and DLS with zeta potential. The stability of Ag/TiO2 nanocomposite is due to the high negative values of zeta potential and capping of constituents present in the biodegradable polymer which is evident from zeta potential and FT-IR studies. The XRD and EDS pattern of synthesized Ag/TiO2 NCs showed their crystalline structure, with face centered cubic geometry oriented in (111) plane. AFM and DLS studies revealed that the diameter of stable Ag/TiO2 NCs was approximately 35nm. Moreover the catalytic activity of synthesize Ag/TiO2 NCs in the reduction of methylene blue was studied by UV-visible spectrophotometer. The synthesized Ag/TiO2 NCs are observed to have a good catalytic activity on the reduction of methylene blue by bio-degradable which is confirmed by the decrease in absorbance maximum value of methylene blue with respect to time using UV-vis spectrophotometer. The significant enhancement in the photocatalytic activity of Ag/TiO2 nanocomposites under sun light irradiation can be ascribed to the effect of noble metal Ag by acting as electron traps in TiO2 band gap. Copyright © 2015. Published by Elsevier Inc.

Biodegradability and mechanical properties of PP/HMSPP and natural polymers bio-composites in function of gamma-irradiation

International Nuclear Information System (INIS)

Cardoso, Elisabeth C.L.; Scagliusi, Sandra R.; Lima, Luis F.C.P.; Bueno, Nelson R.; Parra, Duclerc F.; Lugao, Ademar B.

2013-01-01

PP, expressed as C n H 2n , is one of the most widely used linear hydrocarbon polymers; its versatility arises from the fact that it is made from cheap petrochemical feed stocks through efficient catalytic polymerization process and easy processing to various products. Thus, enormous production and utilization of polymers, in general, lead to their accumulation in the environment, since they are not easily degraded by microorganisms, presenting a serious source of pollution affecting both flora and fauna. These polymers are very bio-resistant due to the involvement of only carbon atoms in main chain with no hydrolyzable functional group. Non-degradable plastics accumulate in the environment at a rate of 25 million tons per year. In recent years, as a result of growing environmental awareness, natural polymers have been increasingly used as reinforcing fillers in thermoplastic composite materials. Sugarcane bagasse was used as reinforcing filler, considering that Brazil is the largest world producer of this crop, with a 101 Mt main agro-industrial residue of sugarcane processing from 340 Mt of sugarcane. Bio-composites were compounded on a twin-screw extruder and samples collected directly from the die. This study aims to investigate mechanical properties of PP/HMSPP-sugarcane bagasse 10, 15, 30 and 50% blends gamma-irradiated at 50, 100, 150 and 200 kGy doses. Degradation essays will comprise DSC and TGA tests and biodegradability behavior will be indicated by Laboratory Soil Burial Test. The main objective of this work is to support the application of these composites as environmentally friendly materials, without prejudicing mechanicals properties, in spite of applied gamma-irradiation. (author)

Comparison of Durable-Polymer Zotarolimus-Eluting and Biodegradable-Polymer Biolimus-Eluting Coronary Stents in Patients With Coronary Artery Disease

DEFF Research Database (Denmark)

Raungaard, Bent; Christiansen, Evald H; Bøtker, Hans Erik

2017-01-01

artery disease or acute coronary syndromes and at least 1 coronary artery lesion requiring treatment with a drug-eluting stent. Endpoints included major adverse cardiac events (MACE), a composite of safety (cardiac death and myocardial infarction not clearly attributable to a non-target lesion......OBJECTIVES: The authors sought to compare the safety and efficacy of the biocompatible durable-polymer zotarolimus-eluting stent with the biodegradable-polymer biolimus-eluting stent in unselected coronary patients. BACKGROUND: Biodegradable-polymer biolimus-eluting stents are superior to first......-generation durable-polymer drug-eluting stents in long-term randomized all-comer trials. Long-term data comparing them to second-generation durable-polymer drug-eluting stents are lacking. METHODS: The study was a randomized, multicenter, all-comer, noninferiority trial in patients with chronic stable coronary...

A phenomenological constitutive model for the nonlinear viscoelastic responses of biodegradable polymers

KAUST Repository

Khan, Kamran; El Sayed, Tamer S.

2012-01-01

We formulate a constitutive framework for biodegradable polymers that accounts for nonlinear viscous behavior under regimes with large deformation. The generalized Maxwell model is used to represent the degraded viscoelastic response of a polymer

Bio-degradable highly fluorescent conjugated polymer nanoparticles for bio-medical imaging applications.

Science.gov (United States)

Repenko, Tatjana; Rix, Anne; Ludwanowski, Simon; Go, Dennis; Kiessling, Fabian; Lederle, Wiltrud; Kuehne, Alexander J C

2017-09-07

Conjugated polymer nanoparticles exhibit strong fluorescence and have been applied for biological fluorescence imaging in cell culture and in small animals. However, conjugated polymer particles are hydrophobic and often chemically inert materials with diameters ranging from below 50 nm to several microns. As such, conjugated polymer nanoparticles cannot be excreted through the renal system. This drawback has prevented their application for clinical bio-medical imaging. Here, we present fully conjugated polymer nanoparticles based on imidazole units. These nanoparticles can be bio-degraded by activated macrophages. Reactive oxygen species induce scission of the conjugated polymer backbone at the imidazole unit, leading to complete decomposition of the particles into soluble low molecular weight fragments. Furthermore, the nanoparticles can be surface functionalized for directed targeting. The approach opens a wide range of opportunities for conjugated polymer particles in the fields of medical imaging, drug-delivery, and theranostics.Conjugated polymer nanoparticles have been applied for biological fluorescence imaging in cell culture and in small animals, but cannot readily be excreted through the renal system. Here the authors show fully conjugated polymer nanoparticles based on imidazole units that can be bio-degraded by activated macrophages.

Novel bio-based and biodegradable polymer blends

Science.gov (United States)

Yang, Shengzhe

Most plastic materials, including high performance thermoplastics and thermosets are produced entirely from petroleum-based products. The volatility of the natural oil markets and the increasing cost of petroleum have led to a push to reduce the dependence on petroleum products. Together with an increase in environmental awareness, this has promoted the use of alternative, biorenewable, environmentally-friendly products, such as biomass. The growing interest in replacing petroleum-based products by inexpensive, renewable, natural materials is important for sustainable development into the future and will have a significant impact on the polymer industry and the environment. This thesis involved characterization and development of two series of novel bio-based polymer blends, namely polyhydroxyalkanoate (PHA)/polyamide (PA) and poly(lactic acid) (PLA)/soy protein. Blends with different concentrations and compatible microstructures were prepared using twin-screw extruder. For PHA/PA blends, the poor mechanical properties of PHA improved significantly with an excellent combination of strength, stiffness and toughness by adding PA. Furthermore, the effect of blending on the viscoelastic properties has been investigated using small-amplitude oscillatory shear flow experiments as a function of blend composition and angular frequency. The elastic shear modulus (G‧) and complex viscosity of the blends increased significantly with increasing the concentration of PHA. Blending PLA with soy protein aims at reducing production cost, as well as accelerating the biodegradation rate in soil medium. In this work, the mechanical, thermal and morphological properties of the blends were investigated using dynamic mechanical analysis (DMA), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), and tensile tests.

Poly(dopamine) coating to biodegradable polymers for bone tissue engineering.

Science.gov (United States)

Tsai, Wei-Bor; Chen, Wen-Tung; Chien, Hsiu-Wen; Kuo, Wei-Hsuan; Wang, Meng-Jiy

2014-02-01

In this study, a technique based on poly(dopamine) deposition to promote cell adhesion was investigated for the application in bone tissue engineering. The adhesion and proliferation of rat osteoblasts were evaluated on poly(dopamine)-coated biodegradable polymer films, such as polycaprolactone, poly(l-lactide) and poly(lactic-co-glycolic acid), which are commonly used biodegradable polymers in tissue engineering. Cell adhesion was significantly increased to a plateau by merely 15 s of dopamine incubation, 2.2-4.0-folds of increase compared to the corresponding untreated substrates. Cell proliferation was also greatly enhanced by poly(dopamine) deposition, indicated by shortened cell doubling time. Mineralization was also increased on the poly(dopamine)-deposited surfaces. The potential of poly(dopamine) deposition in bone tissue engineering is demonstrated in this study.

A phenomenological constitutive model for the nonlinear viscoelastic responses of biodegradable polymers

KAUST Repository

Khan, Kamran

2012-11-09

We formulate a constitutive framework for biodegradable polymers that accounts for nonlinear viscous behavior under regimes with large deformation. The generalized Maxwell model is used to represent the degraded viscoelastic response of a polymer. The large-deformation, time-dependent behavior of viscoelastic solids is described using an Ogden-type hyperviscoelastic model. A deformation-induced degradation mechanism is assumed in which a scalar field depicts the local state of the degradation, which is responsible for the changes in the material\\'s properties. The degradation process introduces another timescale (the intrinsic material clock) and an entropy production mechanism. Examples of the degradation of a polymer under various loading conditions, including creep, relaxation and cyclic loading, are presented. Results from parametric studies to determine the effects of various parameters on the process of degradation are reported. Finally, degradation of an annular cylinder subjected to pressure is also presented to mimic the effects of viscoelastic arterial walls (the outer cylinder) on the degradation response of a biodegradable stent (the inner cylinder). A general contact analysis is performed. As the stiffness of the biodegradable stent decreases, stress reduction in the stented viscoelastic arterial wall is observed. The integration of the proposed constitutive model with finite element software could help a designer to predict the time-dependent response of a biodegradable stent exhibiting finite deformation and under complex mechanical loading conditions. © 2012 Springer-Verlag Wien.

The Recent Developments in Biobased Polymers toward General and Engineering Applications: Polymers that Are Upgraded from Biodegradable Polymers, Analogous to Petroleum-Derived Polymers, and Newly Developed

OpenAIRE

Nakajima, Hajime; Dijkstra, Peter; Loos, Katja

2017-01-01

The main motivation for development of biobased polymers was their biodegradability, which is becoming important due to strong public concern about waste. Reflecting recent changes in the polymer industry, the sustainability of biobased polymers allows them to be used for general and engineering applications. This expansion is driven by the remarkable progress in the processes for refining biomass feedstocks to produce biobased building blocks that allow biobased polymers to have more versati...

A Review on Recent Advances in Stabilizing Peptides/Proteins upon Fabrication in Hydrogels from Biodegradable Polymers

OpenAIRE

Faisal Raza; Hajra Zafar; Ying Zhu; Yuan Ren; Aftab -Ullah; Asif Ullah Khan; Xinyi He; Han Han; Md Aquib; Kofi Oti Boakye-Yiadom; Liang Ge

2018-01-01

Hydrogels evolved as an outstanding carrier material for local and controlled drug delivery that tend to overcome the shortcomings of old conventional dosage forms for small drugs (NSAIDS) and large peptides and proteins. The aqueous swellable and crosslinked polymeric network structure of hydrogels is composed of various natural, synthetic and semisynthetic biodegradable polymers. Hydrogels have remarkable properties of functionality, reversibility, sterilizability, and biocompatibility. All...

Biodegradation of Synthetic Polymers by Composting and Fungal Treatment

Czech Academy of Sciences Publication Activity Database

Šašek, Václav; Vitásek, J.; Chromcová, D.; Prokopová, I.; Brožek, J.; Náhlík, J.

2006-01-01

Roč. 51, č. 5 (2006), s. 425-430 ISSN 0015-5632 R&D Projects: GA ČR GA203/03/0508 Institutional research plan: CEZ:AV0Z50200510 Keywords : biodegradation * composting * synthetic polymers Subject RIV: EE - Microbiology, Virology Impact factor: 0.963, year: 2006

The SYNERGY biodegradable polymer everolimus eluting coronary stent: Porcine vascular compatibility and polymer safety study.

Science.gov (United States)

Wilson, Gregory J; Marks, Angela; Berg, Kimberly J; Eppihimer, Michael; Sushkova, Natalia; Hawley, Steve P; Robertson, Kimberly A; Knapp, David; Pennington, Douglas E; Chen, Yen-Lane; Foss, Aaron; Huibregtse, Barbara; Dawkins, Keith D

2015-11-15

SYNERGY is a novel platinum chromium alloy stent that delivers abluminal everolimus from an ultrathin poly-lactide-co-glycide (PLGA) biodegradable polymer. This study evaluated the in vivo degradation of the polymer coating, everolimus release time course, and vascular compatibility of the SYNERGY stent. SYNERGY stents were implanted in arteries of domestic swine. Devices were explanted at predetermined time points (up to 120 days) and the extent of PLGA coating or everolimus remaining on the stents was quantified. Everolimus levels in the arterial tissue were also evaluated. A pathological analysis on coronary arteries of single and overlapping stents was performed at time points between 5 and 270 days. PLGA bioabsorption began immediately after implantation, and drug release was essentially complete by 90 days; PLGA absorption was substantially complete by 120 days (>90% of polymer was absorbed) leaving a bare metal SYNERGY stent. Vascular response was similar among SYNERGY and control stents (bare metal, polymer-only, and 3× polymer-only). Mild increases in para-strut fibrin were seen for SYNERGY at an early time point with no significant differences in all other morphological and morphometric parameters through 270 days or endothelial function (eNOS immunostaining) at 90 or 180 days. Inflammation was predominantly minimal to mild for all device types. In a swine model, everolimus was released by 90 days and PLGA bioabsorption was complete shortly thereafter. The SYNERGY stent and its biodegradable polymer, even at a 3× safety margin, demonstrated vascular compatibility similar to bare metal stent controls. © 2015 Wiley Periodicals, Inc.

Natural and synthetic polymers for wounds and burns dressing.

Science.gov (United States)

Mogoşanu, George Dan; Grumezescu, Alexandru Mihai

2014-03-25

In the last years, health care professionals faced with an increasing number of patients suffering from wounds and burns difficult to treat and heal. During the wound healing process, the dressing protects the injury and contributes to the recovery of dermal and epidermal tissues. Because their biocompatibility, biodegradability and similarity to macromolecules recognized by the human body, some natural polymers such as polysaccharides (alginates, chitin, chitosan, heparin, chondroitin), proteoglycans and proteins (collagen, gelatin, fibrin, keratin, silk fibroin, eggshell membrane) are extensively used in wounds and burns management. Obtained by electrospinning technique, some synthetic polymers like biomimetic extracellular matrix micro/nanoscale fibers based on polyglycolic acid, polylactic acid, polyacrylic acid, poly-ɛ-caprolactone, polyvinylpyrrolidone, polyvinyl alcohol, polyethylene glycol, exhibit in vivo and in vitro wound healing properties and enhance re-epithelialization. They provide an optimal microenvironment for cell proliferation, migration and differentiation, due to their biocompatibility, biodegradability, peculiar structure and good mechanical properties. Thus, synthetic polymers are used also in regenerative medicine for cartilage, bone, vascular, nerve and ligament repair and restoration. Biocompatible with fibroblasts and keratinocytes, tissue engineered skin is indicated for regeneration and remodeling of human epidermis and wound healing improving the treatment of severe skin defects or partial-thickness burn injuries. Copyright © 2013 Elsevier B.V. All rights reserved.

Lactic Acid Polymers as Biodegradable Carriers of Fluoroquinolones: An In Vitro Study

OpenAIRE

Kanellakopoulou, Kyriaki; Kolia, Maria; Anastassiadis, Antonios; Korakis, Themistoklis; Giamarellos-Bourboulis, Evangelos J.; Andreopoulos, Andreas; Dounis, Eleftherios; Giamarellou, Helen

1999-01-01

A biodegradable polymer of dl-dilactide that facilitates release of ciprofloxacin or pefloxacin at levels exceeding MICs for the causative microorganisms of chronic osteomyelitis is described. Duration and peak of release were found to depend on the molecular weight of the polymer. Its characteristics make it promising for treating chronic bone infections.

Approaches in biotechnological applications of natural polymers

Directory of Open Access Journals (Sweden)

José A. Teixeira

2016-08-01

Full Text Available Natural polymers, such as gums and mucilage, are biocompatible, cheap, easily available and non-toxic materials of native origin. These polymers are increasingly preferred over synthetic materials for industrial applications due to their intrinsic properties, as well as they are considered alternative sources of raw materials since they present characteristics of sustainability, biodegradability and biosafety. As definition, gums and mucilages are polysaccharides or complex carbohydrates consisting of one or more monosaccharides or their derivatives linked in bewildering variety of linkages and structures. Natural gums are considered polysaccharides naturally occurring in varieties of plant seeds and exudates, tree or shrub exudates, seaweed extracts, fungi, bacteria, and animal sources. Water-soluble gums, also known as hydrocolloids, are considered exudates and are pathological products; therefore, they do not form a part of cell wall. On the other hand, mucilages are part of cell and physiological products. It is important to highlight that gums represent the largest amounts of polymer materials derived from plants. Gums have enormously large and broad applications in both food and non-food industries, being commonly used as thickening, binding, emulsifying, suspending, stabilizing agents and matrices for drug release in pharmaceutical and cosmetic industries. In the food industry, their gelling properties and the ability to mold edible films and coatings are extensively studied. The use of gums depends on the intrinsic properties that they provide, often at costs below those of synthetic polymers. For upgrading the value of gums, they are being processed into various forms, including the most recent nanomaterials, for various biotechnological applications. Thus, the main natural polymers including galactomannans, cellulose, chitin, agar, carrageenan, alginate, cashew gum, pectin and starch, in addition to the current researches about them

A Review on Natural Fiber Reinforced Polymer Composite and Its Applications

Directory of Open Access Journals (Sweden)

Layth Mohammed

2015-01-01

Full Text Available Natural fibers are getting attention from researchers and academician to utilize in polymer composites due to their ecofriendly nature and sustainability. The aim of this review article is to provide a comprehensive review of the foremost appropriate as well as widely used natural fiber reinforced polymer composites (NFPCs and their applications. In addition, it presents summary of various surface treatments applied to natural fibers and their effect on NFPCs properties. The properties of NFPCs vary with fiber type and fiber source as well as fiber structure. The effects of various chemical treatments on the mechanical and thermal properties of natural fibers reinforcements thermosetting and thermoplastics composites were studied. A number of drawbacks of NFPCs like higher water absorption, inferior fire resistance, and lower mechanical properties limited its applications. Impacts of chemical treatment on the water absorption, tribology, viscoelastic behavior, relaxation behavior, energy absorption flames retardancy, and biodegradability properties of NFPCs were also highlighted. The applications of NFPCs in automobile and construction industry and other applications are demonstrated. It concluded that chemical treatment of the natural fiber improved adhesion between the fiber surface and the polymer matrix which ultimately enhanced physicomechanical and thermochemical properties of the NFPCs.

Development of biodegradable metaloxide/polymer nanocomposite films based on poly-ε-caprolactone and terephthalic acid

Energy Technology Data Exchange (ETDEWEB)

Varaprasad, Kokkarachedu, E-mail: varmaindian@gmail.com [Centro de Investigación de Polímeros Avanzados (CIPA), Avenida Collao 1202, Edificio de Laboratorios, Concepción (Chile); Pariguana, Manuel [Centro de Investigación de Polímeros Avanzados (CIPA), Avenida Collao 1202, Edificio de Laboratorios, Concepción (Chile); Centro de Innovación Tecnológica Agroindustrial CITE Agroindustrial, Panamericana Sur Km, 293.3, Ica (Peru); Raghavendra, Gownolla Malegowd [Department of Packaging, Yonsei University, Wonju, Gangwon-do 220 710 (Korea, Republic of); Jayaramudu, Tippabattini [Center for Nano Cellulose Future Composites, Department of Mechanical Engineering, Inha University, 253 Yonghyun-Dong, Nam-Ku, Incheon 402–751 (Korea, Republic of); Sadiku, Emmanuel Rotimi [Department of Polymer Technology, Tshwane University of Technology, CSIR-Campus, Pretoria 0040 (South Africa)

2017-01-01

The present investigation describes the development of metal-oxide polymer nanocomposite films from biodegradable poly-ε-caprolactone, disposed poly(ethylene terephthalate) oil bottles monomer and zinc oxide-copper oxide nanoparticles. The terephthalic acid and zinc oxide-copper oxide nanoparticles were synthesized by using a temperature-dependent precipitation technique and double precipitation method, respectively. The terephthalic acid synthesized was confirmed by FTIR analysis and furthermore, it was characterized by thermal analysis. The as-prepared CuO-ZnO nanoparticles structure was confirmed by XRD analysis and its morphology was analyzed by SEM/EDS and TEM. Furthermore, the metal-oxide polymer nanocomposite films have excellent mechanical properties, with tensile strength and modulus better than pure films. The metal-oxide polymer nanocomposite films that were successfully developed show a relatively brighter colour when compared to CuO film. These new metal-oxide polymer nanocomposite films can replace many non-degradable plastics. The new metal-oxide polymer nanocomposite films developed are envisaged to be suitable for use in industrial and domestic packaging applications. - Graphical abstract: Biodegradable metal-oxide/polymer nanocomposites films prepared by using poly-ε-caprolactone with disposed PET oil bottles terephthalic acid monomer. The development of biodegradable film provides a new material with desirable mechanical, physical and chemical properties and can be utilized for industrial applications. - Highlights: • Terephthalic acid obtained from disposed PET oil bottles via precipitation technique. • New nano metal-oxides were developed by double precipitation technique. • Nano metal-oxide polymer films were synthesized by solvent evaporation method. • Nano metal-oxide polymer films exhibit superior mechanical characteristics.

Biodegradable multifunctional oil production chemicals: Thermal polyaspartates

International Nuclear Information System (INIS)

Ross, R.J.; Ravenscroft, P.D.

1996-01-01

The paper deals with biodegradable oil production chemicals. Control of both mineral scale and corrosion with a single, environmentally acceptable material is an ambitious goal. Polyaspartate polymers represent a significant milestone in the attainment of this goal. Thermal polyaspartates (TPA) are polycarboxylate polymers derived via thermal condensation of the naturally occurring amino acid aspartic acid. These protein-like polymers are highly biodegradable and non-toxic, and are produced by an environmentally benign manufacturing process. TPAs exhibit excellent mineral scale inhibition activity and CO 2 corrosion control. Laboratory data on scale inhibition and corrosion control in the North Sea oil field production applications is presented. 8 refs., 2 figs., 6 tabs

Biodegradable multifunctional oil production chemicals: Thermal polyaspartates

Energy Technology Data Exchange (ETDEWEB)

Ross, R J [Donlar Corporation (United States); Ravenscroft, P D [BP Exploration Operating Company, (United Kingdom)

1997-12-31

The paper deals with biodegradable oil production chemicals. Control of both mineral scale and corrosion with a single, environmentally acceptable material is an ambitious goal. Polyaspartate polymers represent a significant milestone in the attainment of this goal. Thermal polyaspartates (TPA) are polycarboxylate polymers derived via thermal condensation of the naturally occurring amino acid aspartic acid. These protein-like polymers are highly biodegradable and non-toxic, and are produced by an environmentally benign manufacturing process. TPAs exhibit excellent mineral scale inhibition activity and CO{sub 2} corrosion control. Laboratory data on scale inhibition and corrosion control in the North Sea oil field production applications is presented. 8 refs., 2 figs., 6 tabs.

Biodegradable modified Phba systems

International Nuclear Information System (INIS)

Aniscenko, L.; Dzenis, M.; Erkske, D.; Tupureina, V.; Savenkova, L.; Muizniece - Braslava, S.

2004-01-01

Compositions as well as production technology of ecologically sound biodegradable multicomponent polymer systems were developed. Our objective was to design some bio plastic based composites with required mechanical properties and biodegradability intended for use as biodegradable packaging. Significant characteristics required for food packaging such as barrier properties (water and oxygen permeability) and influence of γ-radiation on the structure and changes of main characteristics of some modified PHB matrices was evaluated. It was found that barrier properties were plasticizers chemical nature and sterilization with γ-radiation dependent and were comparable with corresponding values of typical polymeric packaging films. Low γ-radiation levels (25 kGy) can be recommended as an effective sterilization method of PHB based packaging materials. Purposely designed bio plastic packaging may provide an alternative to traditional synthetic packaging materials without reducing the comfort of the end-user due to specific qualities of PHB - biodegradability, Biocompatibility and hydrophobic nature

Processing and characterization of solid and microcellular biobased and biodegradable PHBV-based polymer blends and composites

Science.gov (United States)

Javadi, Alireza

Petroleum-based polymers have made a significant contribution to human society due to their extraordinary adaptability and processability. However, due to the wide-spread application of plastics over the past few decades, there are growing concerns over depleting fossil resources and the undesirable environmental impact of plastics. Most of the petroleum-based plastics are non-biodegradable and thus will be disposed in landfills. Inappropriate disposal of plastics may also become a potential threat to the environment. Many approaches, such as efficient plastics waste management and replacing petroleum-based plastics with biodegradable materials obtained from renewable resources, have been put forth to overcome these problems. Plastics waste management is at its beginning stages of development which is also more expensive than expected. Thus, there is a growing interest in developing sustainable biobased and biodegradable materials produced from renewable resources such as plants and crops, which can offer comparable performance with additional advantages, such as biodegradability, biocompatibility, and reducing the carbon footprint. Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) is one of the most promising biobased and biodegradable polymers, In fact many petroleum based polymers such as poly(propylene) (PP) can be potentially replaced by PHBV because of the similarity in their properties. Despite PHBV's attractive properties, there are many drawbacks such as high cost, brittleness, and thermal instability, which hamper the widespread usage of this specific polymer. The goals of this study are to investigate various strategies to address these drawbacks, including blending with other biodegradable polymers such as poly (butylene adipate-coterephthalate) (PBAT) or fillers (e.g., coir fiber, recycled wood fiber, and nanofillers) and use of novel processing technologies such as microcellular injection molding technique. Microcellular injection molding technique

Zotarolimus-eluting durable-polymer-coated stent versus a biolimus-eluting biodegradable-polymer-coated stent in unselected patients undergoing percutaneous coronary intervention (SORT OUT VI)

DEFF Research Database (Denmark)

Raungaard, Bent; Jensen, Lisette Okkels; Tilsted, Hans-Henrik

2015-01-01

BACKGROUND: New-generation drug-eluting coronary stents have reduced the risk of coronary events, especially in patients with complex disease or lesions. To what extent different stent platforms, polymers, and antiproliferative drugs affect outcomes, however, is unclear. We investigated the safety...... and efficacy of a third-generation stent by comparing a highly biocompatible durable-polymer-coated zotarolimus-eluting stent with a biodegradable-polymer-coated biolimus-eluting stent. METHODS: This open-label, randomised, multicentre, non-inferiority trial was done at three sites across western Denmark. All......-polymer zotarolimus-eluting stent or the biodegradable-polymer biolimus-eluting stent. The primary endpoint was a composite of safety (cardiac death and myocardial infarction not clearly attributable to a non-target lesion) and efficacy (target-lesion revascularisation) at 12 months, analysed by intention to treat...

Products Based on Bio-Resourced Materials for Agriculture. Radiation Processed Biodegradable Polymers, Plant Growth Promoters and Superabsorbent Polymers. Chapter 9

Energy Technology Data Exchange (ETDEWEB)

Dubey, K. A.; Bhardwaj, Y. K.; Chaudhari, C. V.; Varshney, L. [Radiation Technology Development Division, Bhabha Atomic Research Centre (India)

2014-07-15

Radiation-processed natural polymers and their derivatives, namely starch, alginate, chitosan and carboxymethyl cellulose (CMC) were explored for different agricultural applications such as biodegradable mulch films, super adsorbent polymers (SAPs), and plant growth promoters (PGPs). It was observed that gamma radiation-processed starch can lead to a better processability of starch/synthetic polymer alloys, and can offer tuneable biodegradability (as low as one month) with acceptable physico-mechanical properties. Acrylic acid/CMC-based SAP was prepared using {sup 60}Co gamma radiation, for soil conditioning. The equilibrium degree of swelling (EDS) of the acrylic acid/CMC SAP was found to be 460 g/g. The field trial of the SAP was conducted on sorghum. It was found that, with the use of 20 kg/ha of SAP, the crop yield can be increased by almost 18.5% whereas the increase in plant height was 8.5%. A new super adsorbent polymer with a much higher water uptake capacity was also developed by adding a small fraction of carrageenan to neutralized acrylic acid (AA). This SAP had EDS of 800 g/g, with the addition of only 1% carrageenan. Experiments to check the soil conditioning efficacy of AA/carrageenan SAP are in progress. Oligomers of chitosan and alginates were prepared by gamma irradiation and were tried as plant growth promoters in wheat (Triticum aestivum), mung bean (Vigna radiata), linseed (Linum usitatissimum), mentha (Mentha arvensis), and lemon grass. The results suggest that these oligomers have a significant impact on the grain and oil yield. Large scale field trials on Mentha arvensis in collaboration with an industry are in progress, and efforts are going on to formulate a policy framework for the use of oligosaccharides as plant growth promoters. (author)

Investigation of Bauschinger effect in thermo-plastic polymers for biodegradable stents

Directory of Open Access Journals (Sweden)

Schümann Kerstin

2017-09-01

Full Text Available The Bauschinger effect is a phenomenon metals show as a result of plastic deformation. After a primary plastic deformation the yield strength in the opposite loading direction decreases. The aim of this study is to investigate if there is a phenomenon similar to Bauschinger effect in thermoplastic polymers for stent application that would influence the mechanical properties of these biodegradable implants. Combined uniaxial tensile with subsequent compression tests as well as conventional compression tests without prior tensile loading were performed using biodegradable polymers for stent application (PLLA and a PLLA based blend. Comparing the results of compression tests with prior tensile loading to the compression-only tests a decrease in compressive strength can be observed for both of the tested materials. The conclusion of the performed experiments is that there is a phenomenon similar to Bauschinger effect not only in metallic materials but also in the examined thermoplastic polymers. The observed reduction of compressive strength as a consequence of prior tensile loading can influence the mechanical behaviour, e.g. the radial strength, of polymeric stents after sustaining a complex load history due to crimping and expansion.

Characterization of biodegradable polymers irradiated with swift heavy ions

International Nuclear Information System (INIS)

Salguero, N.G.; Grosso, M.F. del; Durán, H.; Peruzzo, P.J.; Amalvy, J.I.

2012-01-01

In view of their application as biomaterials, there is an increasing interest in developing new methods to induce controlled cell adhesion onto polymeric materials. The critical step in all these methods involves the modification of polymer surfaces, to induce cell adhesion, without changing theirs degradation and biocompatibility properties. In this work two biodegradable polymers, polyhydroxybutyrate (PHB) and poly-L-lactide acid (PLLA) were irradiated using carbon and sulfur beams with different energies and fluences. Pristine and irradiated samples were degradated by immersion in a phosphate buffer at pH 7.0 and then characterized. The analysis after irradiation and degradation showed a decrease in the contact angle values and changes in their crystallinity properties.

Characterization of biodegradable polymers irradiated with swift heavy ions

Energy Technology Data Exchange (ETDEWEB)

Salguero, N.G. [Gerencia de Investigacion y Aplicaciones, TANDAR-CNEA, Av. Gral. Paz 1499 (B1650KNA) San Martin, Buenos Aires (Argentina); Grosso, M.F. del, E-mail: delgrosso@tandar.cnea.gov.ar [Gerencia de Investigacion y Aplicaciones, TANDAR-CNEA, Av. Gral. Paz 1499 (B1650KNA) San Martin, Buenos Aires (Argentina); CONICET, Av. Rivadavia 1917 C1033AAJ CABA (Argentina); Duran, H. [CONICET, Av. Rivadavia 1917 C1033AAJ CABA (Argentina); Gerencia de Desarrollo Tecnologico y Proyectos Especiales, CNEA, Av. Gral. Paz 1499 (B1650KNA) San Mart Latin-Small-Letter-Dotless-I Acute-Accent n, Buenos Aires (Argentina); Escuela de Ciencia y Tecnologia, H. Yrigoyen 3100, CP 1650, San Martin, UNSAM (Argentina); Peruzzo, P.J. [CICPBA - Grupo de Materiales y Nanomateriales Polimericos, Instituto de Investigaciones Fisicoquimicas Teoricas y Aplicadas (INIFTA), CCT La Plata CONICET - Universidad Nacional de La Plata, La Plata (Argentina); Amalvy, J.I. [CICPBA - Grupo de Materiales y Nanomateriales Polimericos, Instituto de Investigaciones Fisicoquimicas Teoricas y Aplicadas (INIFTA), CCT La Plata CONICET - Universidad Nacional de La Plata, La Plata (Argentina); Facultad de Ingenieria, Universidad Nacional de La Plata, Calle 116 y 48 (B1900TAG), La Plata (Argentina); Departamento de Ingenieria Quimica, Facultad Regional La Plata, Universidad Tecnologica Nacional, 60 y 124 (1900), La Plata (Argentina); and others

2012-02-15

In view of their application as biomaterials, there is an increasing interest in developing new methods to induce controlled cell adhesion onto polymeric materials. The critical step in all these methods involves the modification of polymer surfaces, to induce cell adhesion, without changing theirs degradation and biocompatibility properties. In this work two biodegradable polymers, polyhydroxybutyrate (PHB) and poly-L-lactide acid (PLLA) were irradiated using carbon and sulfur beams with different energies and fluences. Pristine and irradiated samples were degradated by immersion in a phosphate buffer at pH 7.0 and then characterized. The analysis after irradiation and degradation showed a decrease in the contact angle values and changes in their crystallinity properties.

Challenges and opportunities in using Life Cycle Assessment and Cradle to Cradle® for biodegradable bio-based polymers: a review

DEFF Research Database (Denmark)

Niero, Monia; Manat, Renil; Møller, Birger Lindberg

2015-01-01

Both Life Cycle Assessment (LCA) and Cradle to Cradle® (C2C) approaches can provide operative insightsin the design of biodegradable bio-based polymers. Some of the challenges shared by both LCA and C2Cthat need further investigation are the use of lab scale data versus primary data from establis......Both Life Cycle Assessment (LCA) and Cradle to Cradle® (C2C) approaches can provide operative insightsin the design of biodegradable bio-based polymers. Some of the challenges shared by both LCA and C2Cthat need further investigation are the use of lab scale data versus primary data from...... establishedtechnologies and the identification of the best option for the end of use stage, e.g. for use as packaging. Weconsider the case of a natural fiber-based composite material obtained from barley straw and present someinsights from both LCA and C2C perspectives in the identification of the best option for its end...

Biodegradable 3D printed polymer microneedles for transdermal drug delivery.

Science.gov (United States)

Luzuriaga, Michael A; Berry, Danielle R; Reagan, John C; Smaldone, Ronald A; Gassensmith, Jeremiah J

2018-04-17

Biodegradable polymer microneedle (MN) arrays are an emerging class of transdermal drug delivery devices that promise a painless and sanitary alternative to syringes; however, prototyping bespoke needle architectures is expensive and requires production of new master templates. Here, we present a new microfabrication technique for MNs using fused deposition modeling (FDM) 3D printing using polylactic acid, an FDA approved, renewable, biodegradable, thermoplastic material. We show how this natural degradability can be exploited to overcome a key challenge of FDM 3D printing, in particular the low resolution of these printers. We improved the feature size of the printed parts significantly by developing a post fabrication chemical etching protocol, which allowed us to access tip sizes as small as 1 μm. With 3D modeling software, various MN shapes were designed and printed rapidly with custom needle density, length, and shape. Scanning electron microscopy confirmed that our method resulted in needle tip sizes in the range of 1-55 μm, which could successfully penetrate and break off into porcine skin. We have also shown that these MNs have comparable mechanical strengths to currently fabricated MNs and we further demonstrated how the swellability of PLA can be exploited to load small molecule drugs and how its degradability in skin can release those small molecules over time.

Monitoring of the Enzymatically Catalyzed Degradation of Biodegradable Polymers by Means of Capacitive Field-Effect Sensors.

Science.gov (United States)

Schusser, Sebastian; Krischer, Maximilian; Bäcker, Matthias; Poghossian, Arshak; Wagner, Patrick; Schöning, Michael J

2015-07-07

Designing novel or optimizing existing biodegradable polymers for biomedical applications requires numerous tests on the effect of substances on the degradation process. In the present work, polymer-modified electrolyte-insulator-semiconductor (PMEIS) sensors have been applied for monitoring an enzymatically catalyzed degradation of polymers for the first time. The thin films of biodegradable polymer poly(D,L-lactic acid) and enzyme lipase were used as a model system. During degradation, the sensors were read-out by means of impedance spectroscopy. In order to interpret the data obtained from impedance measurements, an electrical equivalent circuit model was developed. In addition, morphological investigations of the polymer surface have been performed by means of in situ atomic force microscopy. The sensor signal change, which reflects the progress of degradation, indicates an accelerated degradation in the presence of the enzyme compared to hydrolysis in neutral pH buffer media. The degradation rate increases with increasing enzyme concentration. The obtained results demonstrate the potential of PMEIS sensors as a very promising tool for in situ and real-time monitoring of degradation of polymers.

Effects of gamma irradiation on the molecular structure and mechanical properties of biodegradable polymer poly(hydroxybutyrate)

International Nuclear Information System (INIS)

Oliveira, Leticia M. de; Araujo, Elmo S.

2005-01-01

The effects of gamma irradiation ( 60 Co) on the properties of the Brazilian biodegradable polymer, Poly(hydroxybutyrate), PHB, i.e. chemical, mechanical and structural properties were investigated. PHB is a natural polyester biosynthesized by different bacteria as a form to store carbon and energy. This new biopolymer shows a great potential in the medical and pharmaceutical applications due to the biocompatibility and biodegradation capacity, since it is reabsorbed by organism without liberation of toxic substances. As it.s well known, gamma irradiation have been considered the more functional sterilization mechanism applied to medical devices. This way, it is necessary to know the effects caused by energy transfer to the polymer system. The viscosity-average molar mass (Mv) of the irradiated PHB, measured using an Ostwald-type capillary viscometer, significantly decreased. The irradiated samples (test specimens) showed a molecular degradation degree, G (scissions/100 eV) value, in the sterilization dose range (0-25 kGy) about 11.4, and 20.9 to doses above 35 kGy. Other results also indicate that the gamma irradiation significantly affected the mechanical properties of PHB. Tensile strength, impact strength and elongation at break decreased dramatically, indicating increasing on the brittleness, because significant chain scissions take place in the amorphous region of irradiated PHB. On the other hand, Young modulus does not significantly change on irradiated polymer. 13 C NMR spectra of irradiated PHB at dose of 200 kGy did not show arising of new structural groups. (author)

Biodegradable and compostable alternatives to conventional plastics

Science.gov (United States)

Song, J. H.; Murphy, R. J.; Narayan, R.; Davies, G. B. H.

2009-01-01

Packaging waste forms a significant part of municipal solid waste and has caused increasing environmental concerns, resulting in a strengthening of various regulations aimed at reducing the amounts generated. Among other materials, a wide range of oil-based polymers is currently used in packaging applications. These are virtually all non-biodegradable, and some are difficult to recycle or reuse due to being complex composites having varying levels of contamination. Recently, significant progress has been made in the development of biodegradable plastics, largely from renewable natural resources, to produce biodegradable materials with similar functionality to that of oil-based polymers. The expansion in these bio-based materials has several potential benefits for greenhouse gas balances and other environmental impacts over whole life cycles and in the use of renewable, rather than finite resources. It is intended that use of biodegradable materials will contribute to sustainability and reduction in the environmental impact associated with disposal of oil-based polymers. The diversity of biodegradable materials and their varying properties makes it difficult to make simple, generic assessments such as biodegradable products are all ‘good’ or petrochemical-based products are all ‘bad’. This paper discusses the potential impacts of biodegradable packaging materials and their waste management, particularly via composting. It presents the key issues that inform judgements of the benefits these materials have in relation to conventional, petrochemical-based counterparts. Specific examples are given from new research on biodegradability in simulated ‘home’ composting systems. It is the view of the authors that biodegradable packaging materials are most suitable for single-use disposable applications where the post-consumer waste can be locally composted. PMID:19528060

Biodegradable and compostable alternatives to conventional plastics.

Science.gov (United States)

Song, J H; Murphy, R J; Narayan, R; Davies, G B H

2009-07-27

Packaging waste forms a significant part of municipal solid waste and has caused increasing environmental concerns, resulting in a strengthening of various regulations aimed at reducing the amounts generated. Among other materials, a wide range of oil-based polymers is currently used in packaging applications. These are virtually all non-biodegradable, and some are difficult to recycle or reuse due to being complex composites having varying levels of contamination. Recently, significant progress has been made in the development of biodegradable plastics, largely from renewable natural resources, to produce biodegradable materials with similar functionality to that of oil-based polymers. The expansion in these bio-based materials has several potential benefits for greenhouse gas balances and other environmental impacts over whole life cycles and in the use of renewable, rather than finite resources. It is intended that use of biodegradable materials will contribute to sustainability and reduction in the environmental impact associated with disposal of oil-based polymers. The diversity of biodegradable materials and their varying properties makes it difficult to make simple, generic assessments such as biodegradable products are all 'good' or petrochemical-based products are all 'bad'. This paper discusses the potential impacts of biodegradable packaging materials and their waste management, particularly via composting. It presents the key issues that inform judgements of the benefits these materials have in relation to conventional, petrochemical-based counterparts. Specific examples are given from new research on biodegradability in simulated 'home' composting systems. It is the view of the authors that biodegradable packaging materials are most suitable for single-use disposable applications where the post-consumer waste can be locally composted.

Conversion of post consumer polyethylene to the biodegradable polymer polyhydroxyalkanoate.

Science.gov (United States)

Guzik, Maciej W; Kenny, Shane T; Duane, Gearoid F; Casey, Eoin; Woods, Trevor; Babu, Ramesh P; Nikodinovic-Runic, Jasmina; Murray, Michael; O'Connor, Kevin E

2014-05-01

A process for the conversion of post consumer (agricultural) polyethylene (PE) waste to the biodegradable polymer medium chain length polyhydroxyalkanoate (mcl-PHA) is reported here. The thermal treatment of PE in the absence of air (pyrolysis) generated a complex mixture of low molecular weight paraffins with carbon chain lengths from C8 to C32 (PE pyrolysis wax). Several bacterial strains were able to grow and produce PHA from this PE pyrolysis wax. The addition of biosurfactant (rhamnolipids) allowed for greater bacterial growth and PHA accumulation of the tested strains. Some strains were only capable of growth and PHA accumulation in the presence of the biosurfactant. Pseudomonas aeruginosa PAO-1 accumulated the highest level of PHA with almost 25 % of the cell dry weight as PHA when supplied with the PE pyrolysis wax in the presence of rhamnolipids. The change of nitrogen source from ammonium chloride to ammonium nitrate resulted in faster bacterial growth and the earlier onset of PHA accumulation. To our knowledge, this is the first report where PE is used as a starting material for production of a biodegradable polymer.

Preparation of new biodegradable materials by grafting of polycarprolactone onto starch and their biodegradability studies

International Nuclear Information System (INIS)

Najemi, L.; Zerroukhi, A.; Jeanmaire, T.; Raihane, M.; Chamkh, F.; Qatibi, A.; Bennisse, R.

2009-01-01

The starch is a natural polymer which has the advantage of being biodegradable, renewable in quantity unlimited at very accessible prices. However its poor mechanical properties, depending on its hydrophobic character, and also its absorption of water restrict is applicability considerable especially for packing. (Author)

Biodegradation test of SPS-LS blends as polymer electrolyte membrane fuel cells

International Nuclear Information System (INIS)

Putri, Zufira; Arcana, I Made

2014-01-01

Sulfonated polystyrene (SPS) can be applied as a proton exchange membrane fuel cell due to its fairly good chemical stability. In order to be applied as polymer electrolyte membrane fuel cells (PEMFCs), membrane polymer should have a good ionic conductivity, high proton conductivity, and high mechanical strength. Lignosulfonate (LS) is a complex biopolymer which has crosslinks and sulfonate groups. SPS-LS blends with addition of SiO 2 are used to increase the proton conductivity and to improve the mechanical properties and thermal stability. However, the biodegradation test of SPS-LS blends is required to determine whether the application of these membranes to be applied as an environmentally friendly membrane. In this study, had been done the synthesis of SPS, biodegradability test of SPS-LS blends with variations of LS and SiO 2 compositions. The biodegradation test was carried out in solid medium of Luria Bertani (LB) with an activated sludge used as a source of microorganism at incubation temperature of 37°C. Based on the results obtained indicated that SPS-LS-SiO 2 blends are more decomposed by microorganism than SPS-LS blends. This result is supported by analysis of weight reduction percentage, functional groups with Fourier Transform Infrared (FTIR) Spectroscopy, and morphological surface with Scanning Electron Microscopy (SEM)

Effect of sterilization dose on electron beam irradiated biodegradable polymers and coconut fiber based composites

Energy Technology Data Exchange (ETDEWEB)

Kodama, Yasko; Machado, Luci D.B., E-mail: ykodama@ipen.b, E-mail: lmachado@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Oishi, Akihiro; Nakayama, Kazuo, E-mail: a.oishi@aist.go.j, E-mail: kazuo-nakayama@jcom.home.ne.j [National Institute of Advanced Industrial Science and Technology (AIST), Ibaraki-ken (Japan). Research Institute for Sustainable Chemical Innovation; Nagasawa, Naotsugu; Tamada, Masao, E-mail: nagasawa.naotsugu@jaea.go.j [Japan Atomic Energy Agency (JAEA), Gunma-ken (Japan). Quantum Beam Science Directorate

2009-07-01

In Brazil, annual production of coconut fruit is 1.5 billion in a cultivated area of 2.7 million ha. Coconut fiber applications as reinforcement for polymer composites, besides reducing the coconut waste, would reduce cost of the composite. On the other hand, biodegradable polymers have been receiving much attention due to the plastic waste problem. Poly(e-caprolactone), PCL, and poly(lactic acid), PLA, besides being biodegradable aliphatic polyesters, are biocompatible polymers. Considering the biomedical application of PLA and PCL, their products must be sterilized for use, and ionizing radiation has been widely used for medical devices sterilization. It is important to study the effect of ionizing radiation on the blends and composites due to the fact that they are based on biocompatible polymers. Is this research, hot pressed samples based on PLA:PCL (80:20, ratio of weight:weight) blend and the composites containing chemically treated or untreated coconut fiber (5, 10%) were irradiated by electron beams and gamma radiation from Co-60 source at doses in the range up to 200 kGy. Thermal mechanical analysis (TMA) and gel fraction measurements were performed in irradiated samples. From TMA curves it can be observed that thermal stability of samples with untreated coconut fiber slightly decreased with increasing fiber content. On the other hand, deformation increased with increasing fiber content. Acetylated coconut fibers slightly decreased thermal stability of samples. It seems that no interaction occurs between the natural fibers and the polymeric matrix due to irradiation. PLLA undergoes to main chain scission under ionizing irradiation according to thermal stability results and also because no gel fraction was observed. In contrast, PCL cross-linking is induced by ionizing radiation that increases thermal stability and decreases deformation. (author)

Effect of sterilization dose on electron beam irradiated biodegradable polymers and coconut fiber based composites

International Nuclear Information System (INIS)

Kodama, Yasko; Machado, Luci D.B.; Oishi, Akihiro; Nakayama, Kazuo; Nagasawa, Naotsugu; Tamada, Masao

2009-01-01

In Brazil, annual production of coconut fruit is 1.5 billion in a cultivated area of 2.7 million ha. Coconut fiber applications as reinforcement for polymer composites, besides reducing the coconut waste, would reduce cost of the composite. On the other hand, biodegradable polymers have been receiving much attention due to the plastic waste problem. Poly(e-caprolactone), PCL, and poly(lactic acid), PLA, besides being biodegradable aliphatic polyesters, are biocompatible polymers. Considering the biomedical application of PLA and PCL, their products must be sterilized for use, and ionizing radiation has been widely used for medical devices sterilization. It is important to study the effect of ionizing radiation on the blends and composites due to the fact that they are based on biocompatible polymers. Is this research, hot pressed samples based on PLA:PCL (80:20, ratio of weight:weight) blend and the composites containing chemically treated or untreated coconut fiber (5, 10%) were irradiated by electron beams and gamma radiation from Co-60 source at doses in the range up to 200 kGy. Thermal mechanical analysis (TMA) and gel fraction measurements were performed in irradiated samples. From TMA curves it can be observed that thermal stability of samples with untreated coconut fiber slightly decreased with increasing fiber content. On the other hand, deformation increased with increasing fiber content. Acetylated coconut fibers slightly decreased thermal stability of samples. It seems that no interaction occurs between the natural fibers and the polymeric matrix due to irradiation. PLLA undergoes to main chain scission under ionizing irradiation according to thermal stability results and also because no gel fraction was observed. In contrast, PCL cross-linking is induced by ionizing radiation that increases thermal stability and decreases deformation. (author)

Biodegraded polymers as materials for sowing of grain crops seeds

Directory of Open Access Journals (Sweden)

L. S. Shibryaeva

2015-01-01

Full Text Available Increase of efficiency of grain production, solution of problems of food security demand search and development of innovative technologies at all stages. One of ways of environmentally friendly production is sowing of seeds on an excipient located in the soil, for example, nonwoven fabric made of eco- decomposable decomposed biodegraded polymer. Biodegraded polymeric materials influence on sowing properties of grain crops seeds and provide realization of their potential productivity. The authors used an electroforming method with chloroform and a dichloroethane application to receive nonwoven fabric from poly-3-hydroxybutyrate (PHB and its compositions together with synthetic nitrile rubber (PHB-SNR. Polymeric material influences on energy of germination and viability of wheat seeds. Germination index is calculated, heat physical parameters are determined for the polymeric excipient. The major factor influencing seeds germination is a structure of nonwoven fabric. Water diffusion, its supply to seeds and their viability depend on morphological features of polymeric material. Polymer excipient structure influence on speed of development of root system on which, in turn, intensity of destruction of polymer depends. The best indicators of energy of germination and viability of seeds correspond to the greatest value of decrease of melting heat of PHB in mix PHB-SNR. In addition, among the studied samples of PHB-SNR the material received from blend of solvents is most effective. The cause is in feature of its structure favorable for a seed germination.

Biodegradability of biobased polymeric materials in natural environments: Structures and Chemistry

CSIR Research Space (South Africa)

Muniyasamy, S

2017-03-01

Full Text Available The development of biobased polymer materials from renewable resources meets the concept of sustainability, offering the potential of renewability, biodegradation, and a path away from the problems associated with plastic derived from nonrenewable...

A review on synthesis, properties and applications of natural polymer based carrageenan blends and composites.

Science.gov (United States)

Zia, Khalid Mahmood; Tabasum, Shazia; Nasif, Muhammad; Sultan, Neelam; Aslam, Nosheen; Noreen, Aqdas; Zuber, Mohammad

2017-03-01

Carrageenan is a natural polysaccharide extracted from edible red seaweeds of Rhodophycea class. It has been used as a viscosity increasing or gelling agent for prolonged and controlled drug release, food, pharmaceuticals and other industries. However, in spite of wide range of applications, carrageenan has some drawbacks and adverse effects on the biological systems, so its modifications with natural and synthetic polymers are carried out. This review article presents different sources and properties of carrageenans with special emphasis on natural polymer based carrageenan blends and composites and their applications in controlled drug delivery system, wound dressing and tissue engineering because of their biodegradability and biocompatibility, food industry as thickening/gelling materials, cosmeceuticals and making polyelectrolyte complexes. Copyright © 2016 Elsevier B.V. All rights reserved.

Perspective highlights on biodegradable polymeric nanosystems for targeted therapy of solid tumors.

Science.gov (United States)

Fathi, Marziyeh; Barar, Jaleh

2017-01-01

Introduction: Polymeric nanoparticles (NPs) formulated using biodegradable polymers offer great potential for development of de novo drug delivery systems (DDSs) capable of delivering a wide range of bioactive agents. They can be engineered as advanced multifunctional nanosystems (NSs) for simultaneous imaging and therapy known as theranostics or diapeutics. Methods: A brief prospective is provided on biomedical importance and applications of biodegradable polymeric NSs through reviewing the recently published literature. Results: Biodegradable polymeric NPs present unique characteristics, including: nanoscaled structures, high encapsulation capacity, biocompatibility with non-thrombogenic and non-immunogenic properties, and controlled-/sustained-release profile for lipophilic and hydrophilic drugs. Once administered in vivo, all classes of biodegradable polymers (i.e., synthetic, semi-synthetic, and natural polymers) are subjected to enzymatic degradation; and hence, transformation into byproducts that can be simply eliminated from the human body. Natural and semi-synthetic polymers have been shown to be highly stable, much safer, and offer a non-/less-toxic means for specific delivery of cargo drugs in comparison with synthetic polymers. Despite being biocompatible and enzymatically-degradable, there are some drawbacks associated with these polymers such as batch to batch variation, high production cost, structural complexity, lower bioadhesive potential, uncontrolled rate of hydration, and possibility of microbial spoilage. These pitfalls have bolded the importance of synthetic counterparts despite their somewhat toxicity. Conclusion: Taken all, to minimize the inadvertent effects of these polymers and to engineer much safer NSs, it is necessary to devise biopolymers with desirable chemical and biochemical modification(s) and polyelectrolyte complex formation to improve their drug delivery capacity in vivo.

Poly-γ-Glutamic Acid: Biodegradable Polymer for Potential Protection of Beneficial Viruses

Directory of Open Access Journals (Sweden)

Ibrahim R. Khalil

2016-01-01

Full Text Available Poly-γ-glutamic acid (γ-PGA is a naturally occurring polymer, which due to its biodegradable, non-toxic and non-immunogenic properties has been used successfully in the food, medical and wastewater industries. A major hurdle in bacteriophage application is the inability of phage to persist for extended periods in the environment due to their susceptibility to environmental factors such as temperature, sunlight, desiccation and irradiation. Thus, the aim of this study was to protect useful phage from the harmful effect of these environmental factors using the γ-PGA biodegradable polymer. In addition, the association between γ-PGA and phage was investigated. Formulated phage (with 1% γ-PGA and non-formulated phage were exposed to 50 °C. A clear difference was noticed as viability of non-formulated phage was reduced to 21% at log10 1.3 PFU/mL, while phage formulated with γ-PGA was 84% at log10 5.2 PFU/mL after 24 h of exposure. In addition, formulated phage remained viable at log10 2.5 PFU/mL even after 24 h of exposure at pH 3 solution. In contrast, non-formulated phages were totally inactivated after the same time of exposure. In addition, non-formulated phages when exposed to UV irradiation died within 10 min. In contrast also phages formulated with 1% γ-PGA had a viability of log10 4.1 PFU/mL at the same exposure time. Microscopy showed a clear interaction between γ-PGA and phages. In conclusion, the results suggest that γ-PGA has an unique protective effect on phage particles.

Role of different biodegradable polymers on the permeability of ciprofloxacin

OpenAIRE

Chakraborti, Chandra Kanti; Sahoo, Subhashree; Behera, Pradipta Kumar

2014-01-01

Since permeability across biological membranes is a key factor in the absorption and distribution of drugs, drug permeation characteristics of three oral suspensions of ciprofloxacin were designed and compared. The three suspensions of ciprofloxacin were prepared by taking biodegradable polymers such as carbopol 934, carbopol 940, and hydroxypropyl methylcellulose (HPMC). The permeability study was performed by using a Franz diffusion cell through both synthetic cellulose acetate membrane and...

Electrically conductive biodegradable polymer composite for nerve regeneration: electricity-stimulated neurite outgrowth and axon regeneration.

Science.gov (United States)

Zhang, Ze; Rouabhia, Mahmoud; Wang, Zhaoxu; Roberge, Christophe; Shi, Guixin; Roche, Phillippe; Li, Jiangming; Dao, Lê H

2007-01-01

Normal and electrically stimulated PC12 cell cultures and the implantation of nerve guidance channels were performed to evaluate newly developed electrically conductive biodegradable polymer composites. Polypyrrole (PPy) doped by butane sulfonic acid showed a significantly higher number of viable cells compared with PPy doped by polystyrenesulfonate after a 6-day culture. The PC12 cells were left to proliferate for 6 days, and the PPy-coated membranes, showing less initial cell adherence, recorded the same proliferation rate as did the noncoated membranes. Direct current electricity at various intensities was applied to the PC12 cell-cultured conductive membranes. After 7 days, the greatest number of neurites appeared on the membranes with a current intensity approximating 1.7-8.4 microA/cm. Nerve guidance channels made of conductive biodegradable composite were implanted into rats to replace 8 mm of sciatic nerve. The implants were harvested after 2 months and analyzed with immunohistochemistry and transmission electron microscopy. The regenerated nerve tissue displayed myelinated axons and Schwann cells that were similar to those in the native nerve. Electrical stimulation applied through the electrically conductive biodegradable polymers therefore enhanced neurite outgrowth in a current-dependent fashion. The conductive polymers also supported sciatic nerve regeneration in rats.

Effect of chemical heterogeneity of biodegradable polymers on surface energy: A static contact angle analysis of polyester model films

Energy Technology Data Exchange (ETDEWEB)

Belibel, R.; Avramoglou, T. [INSERM U1148, Laboratory for Vascular Translational Science (LVTS), Institut Galilée, Université Paris 13, Sorbonne Paris Cité, 99 Avenue Jean-Baptiste Clément, Villetaneuse F-93430 (France); Garcia, A. [CNRS UPR 3407, Laboratoire des Sciences des Procédés et des Matériau, Institut Galilée, Université Paris 13, Sorbonne Paris Cité, 99 Avenue Jean-Baptiste Clément, Villetaneuse F-93430 (France); Barbaud, C. [INSERM U1148, Laboratory for Vascular Translational Science (LVTS), Institut Galilée, Université Paris 13, Sorbonne Paris Cité, 99 Avenue Jean-Baptiste Clément, Villetaneuse F-93430 (France); Mora, L., E-mail: Laurence.mora@univ-paris13.fr [INSERM U1148, Laboratory for Vascular Translational Science (LVTS), Institut Galilée, Université Paris 13, Sorbonne Paris Cité, 99 Avenue Jean-Baptiste Clément, Villetaneuse F-93430 (France)

2016-02-01

Biodegradable and bioassimilable poly((R,S)-3,3 dimethylmalic acid) (PDMMLA) derivatives were synthesized and characterized in order to develop a new coating for coronary endoprosthesis enabling the reduction of restenosis. The PDMMLA was chemically modified to form different custom groups in its side chain. Three side groups were chosen: the hexyl group for its hydrophobic nature, the carboxylic acid and alcohol groups for their acid and neutral hydrophilic character, respectively. The sessile drop method was applied to characterize the wettability of biodegradable polymer film coatings. Surface energy and components were calculated. The van Oss approach helped reach not only the dispersive and polar acid–base components of surface energy but also acid and basic components. Surface topography was quantified by atomic force microscopy (AFM) and subnanometer average values of roughness (Ra) were obtained for all the analyzed surfaces. Thus, roughness was considered to have a negligible effect on wettability measurements. In contrast, heterogeneous surfaces had to be corrected by the Cassie–Baxter equation for copolymers (10/90, 20/80 and 30/70). The impact of this correction was quantified for all the wettability parameters. Very high relative corrections (%) were found, reaching 100% for energies and 30% for contact angles. - Highlights: • We develop different polymers with various chemical compositions. • Wettability properties were calculated using Cassie corrected contact angles. • Percentage of acid groups in polymers is directly correlated to acid part of SFE. • Cassie corrections are necessary for heterogeneous polymers.

Biodegradation test of SPS-LS blends as polymer electrolyte membrane fuel cells

Energy Technology Data Exchange (ETDEWEB)

Putri, Zufira, E-mail: zufira.putri@gmail.com, E-mail: arcana@chem.itb.ac.id; Arcana, I Made, E-mail: zufira.putri@gmail.com, E-mail: arcana@chem.itb.ac.id [Inorganic and Physical Chemistry Research Groups, Faculty of Mathematics and Natural Sciences, Institut Teknologi Bandung, Bandung (Indonesia)

2014-03-24

Sulfonated polystyrene (SPS) can be applied as a proton exchange membrane fuel cell due to its fairly good chemical stability. In order to be applied as polymer electrolyte membrane fuel cells (PEMFCs), membrane polymer should have a good ionic conductivity, high proton conductivity, and high mechanical strength. Lignosulfonate (LS) is a complex biopolymer which has crosslinks and sulfonate groups. SPS-LS blends with addition of SiO{sub 2} are used to increase the proton conductivity and to improve the mechanical properties and thermal stability. However, the biodegradation test of SPS-LS blends is required to determine whether the application of these membranes to be applied as an environmentally friendly membrane. In this study, had been done the synthesis of SPS, biodegradability test of SPS-LS blends with variations of LS and SiO{sub 2} compositions. The biodegradation test was carried out in solid medium of Luria Bertani (LB) with an activated sludge used as a source of microorganism at incubation temperature of 37°C. Based on the results obtained indicated that SPS-LS-SiO{sub 2} blends are more decomposed by microorganism than SPS-LS blends. This result is supported by analysis of weight reduction percentage, functional groups with Fourier Transform Infrared (FTIR) Spectroscopy, and morphological surface with Scanning Electron Microscopy (SEM)

Biodegradable Polymer-Based Scaffolds for Bone Tissue Engineering

CERN Document Server

Sultana, Naznin

2013-01-01

This book addresses the principles, methods and applications of biodegradable polymer based scaffolds for bone tissue engineering. The general principle of bone tissue engineering is reviewed and the traditional and novel scaffolding materials, their properties and scaffold fabrication techniques are explored. By acting as temporary synthetic extracellular matrices for cell accommodation, proliferation, and differentiation, scaffolds play a pivotal role in tissue engineering. This book does not only provide the comprehensive summary of the current trends in scaffolding design but also presents the new trends and directions for scaffold development for the ever expanding tissue engineering applications.

Extracellular matrix production by human osteoblasts cultured on biodegradable polymers applicable for tissue engineering.

Science.gov (United States)

El-Amin, S F; Lu, H H; Khan, Y; Burems, J; Mitchell, J; Tuan, R S; Laurencin, C T

2003-03-01

The nature of the extracellular matrix (ECM) is crucial in regulating cell functions via cell-matrix interactions, cytoskeletal organization, and integrin-mediated signaling. In bone, the ECM is composed of proteins such as collagen (CO), fibronectin (FN), laminin (LM), vitronectin (VN), osteopontin (OP) and osteonectin (ON). For bone tissue engineering, the ECM should also be considered in terms of its function in mediating cell adhesion to biomaterials. This study examined ECM production, cytoskeletal organization, and adhesion of primary human osteoblastic cells on biodegradable matrices applicable for tissue engineering, namely polylactic-co-glycolic acid 50:50 (PLAGA) and polylactic acid (PLA). We hypothesized that the osteocompatible, biodegradable polymer surfaces promote the production of bone-specific ECM proteins in a manner dependent on polymer composition. We first examined whether the PLAGA and PLA matrices could support human osteoblastic cell growth by measuring cell adhesion at 3, 6 and 12h post-plating. Adhesion on PLAGA was consistently higher than on PLA throughout the duration of the experiment, and comparable to tissue culture polystyrene (TCPS). ECM components, including CO, FN, LM, ON, OP and VN, produced on the surface of the polymers were quantified by ELISA and localized by immunofluorescence staining. All of these proteins were present at significantly higher levels on PLAGA compared to PLA or TCPS surfaces. On PLAGA, OP and ON were the most abundant ECM components, followed by CO, FN, VN and LN. Immunofluorescence revealed an extracellular distribution for CO and FN, whereas OP and ON were found both intracellularly as well as extracellularly on the polymer. In addition, the actin cytoskeletal network was more extensive in osteoblasts cultured on PLAGA than on PLA or TCPS. In summary, we found that osteoblasts plated on PLAGA adhered better to the substrate, produced higher levels of ECM molecules, and showed greater cytoskeletal

Biodegradable Nanoparticles Made of Amino-Acid-Based Ester Polymers: Preparation, Characterization, and In Vitro Biocompatibility Study

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Temur Kantaria

2016-12-01

Full Text Available A systematic study of fabricating nanoparticles (NPs by cost-effective polymer deposition/solvent displacement (nanoprecipitation method has been carried out. Five amino acid based biodegradable (AABB ester polymers (four neutral and one cationic, four organic solvents miscible with water, and eight surfactants were tested for the fabrication of the goal NPs. Depending on the nature of the AABB polymers, organic solvents and surfactants, as well as on the fabrication conditions, the size (Mean Particle Diameter of the NPs could be tuned within 42 ÷ 398 nm, the zeta-potential within 12.5 ÷ +28 mV. The stability (resuspendability of the NPs upon storage (at room temperature and refrigerated was tested as well. In Vitro biocompatibility study of the NPs was performed with four different stable cell lines: A549, HeLa (human; RAW264.7, Hepa 1-6 (murine. Comparing the NPs parameters, their stability upon storage, and the data of biological examinations the best were found: As the AABB polymer, a poly(ester amide composed of l-leucine, 1,6-hexanediol and sebacic acid–8L6, as a solvent (organic phase—DMSO, and as a surfactant, Tween 20.

Drug loaded biodegradable load-bearing nanocomposites for damaged bone repair

Science.gov (United States)

Gutmanas, E. Y.; Gotman, I.; Sharipova, A.; Psakhie, S. G.; Swain, S. K.; Unger, R.

2017-09-01

In this paper we present a short review-scientific report on processing and properties, including in vitro degradation, of load bearing biodegradable nanocomposites as well as of macroporous 3D scaffolds for bone ingrowth. Biodegradable implantable devices should slowly degrade over time and disappear with ingrown of natural bone replacing the synthetic graft. Compared to low strength biodegradable polymers, and brittle CaP ceramics, biodegradable CaP-polymer and CaP-metal nanocomposites, mimicking structure of natural bone, as well as strong and ductile metal nanocomposites can provide to implantable devices both strengths and toughness. Nanostructuring of biodegradable β-TCP (tricalcium phosphate)-polymer (PCL and PLA), β-TCP-metal (FeMg and FeAg) and of Fe-Ag composites was achieved employing high energy attrition milling of powder blends. Nanocomposite powders were consolidated to densities close to theoretical by high pressure consolidation at ambient temperature—cold sintering, with retention of nanoscale structure. The strength of developed nanocomposites was significantly higher as compared with microscale composites of the same or similar composition. Heat treatment at moderate temperatures in hydrogen flow resulted in retention of nanoscale structure and higher ductility. Degradation of developed biodegradable β-TCP-polymer, β-TCP-metal and of Fe-Ag nanocomposites was studied in physiological solutions. Immersion tests in Ringer's and saline solution for 4 weeks resulted in 4 to 10% weight loss and less than 50% decrease in compression or bending strength, the remaining strength being significantly higher than the values reported for other biodegradable materials. Nanostructuring of Fe-Ag based materials resulted also in an increase of degradation rate because of creation on galvanic Fe-Ag nanocouples. In cell culture experiments, the developed nanocomposites supported the attachment the human osteoblast cells and exhibited no signs of cytotoxicity

Safe biodegradable fluorescent particles

Science.gov (United States)

Martin, Sue I [Berkeley, CA; Fergenson, David P [Alamo, CA; Srivastava, Abneesh [Santa Clara, CA; Bogan, Michael J [Dublin, CA; Riot, Vincent J [Oakland, CA; Frank, Matthias [Oakland, CA

2010-08-24

A human-safe fluorescence particle that can be used for fluorescence detection instruments or act as a safe simulant for mimicking the fluorescence properties of microorganisms. The particle comprises a non-biological carrier and natural fluorophores encapsulated in the non-biological carrier. By doping biodegradable-polymer drug delivery microspheres with natural or synthetic fluorophores, the desired fluorescence can be attained or biological organisms can be simulated without the associated risks and logistical difficulties of live microorganisms.

A study on thermal properties of biodegradable polymers using photothermal methods

Science.gov (United States)

Siqueira, A. P. L.; Poley, L. H.; Sanchez, R.; da Silva, M. G.; Vargas, H.

2005-06-01

In this work is reported the use of photothermal techniques applied to the thermal characterization of biodegradable polymers of Polyhydroxyalkanoates (PHAs) family. This is a family of polymer produced by bacteria using renewable resources. It exhibits thermoplastic properties and therefore it can be an alternative product for engineering plastics, being also applied as packages for food industry and fruits. Thermal diffusivities were determined using the open photoacoustic cell (OPC) configuration. Specific heat capacity measurements were performed monitoring temperature of the samples under white light illumination against time. Typical values obtained for the thermal properties are in good agreement with those found in the literature for other polymers. Due to the incorporation of hydroxyvalerate in the monomer structure, the thermal diffusivity and thermal conductivity increase reaching a saturation value, otherwise the specific thermal capacity decreases as the concentration of the hydroxyvalerate (HV) increases. These results can be explained by polymers internal structure and are allowing new applications of these materials.

Localized Enzymatic Degradation of Polymers: Physics and Scaling Laws

Science.gov (United States)

Lalitha Sridhar, Shankar; Vernerey, Franck

2018-03-01

Biodegradable polymers are naturally abundant in living matter and have led to great advances in controlling environmental pollution due to synthetic polymer products, harnessing renewable energy from biofuels, and in the field of biomedicine. One of the most prevalent mechanisms of biodegradation involves enzyme-catalyzed depolymerization by biological agents. Despite numerous studies dedicated to understanding polymer biodegradation in different environments, a simple model that predicts the macroscopic behavior (mass and structural loss) in terms of microphysical processes (enzyme transport and reaction) is lacking. An interesting phenomenon occurs when an enzyme source (released by a biological agent) attacks a tight polymer mesh that restricts free diffusion. A fuzzy interface separating the intact and fully degraded polymer propagates away from the source and into the polymer as the enzymes diffuse and react in time. Understanding the characteristics of this interface will provide crucial insight into the biodegradation process and potential ways to precisely control it. In this work, we present a centrosymmetric model of biodegradation by characterizing the moving fuzzy interface in terms of its speed and width. The model predicts that the characteristics of this interface are governed by two time scales, namely the polymer degradation and enzyme transport times, which in turn depend on four main polymer and enzyme properties. A key finding of this work is simple scaling laws that can be used to guide biodegradation of polymers in different applications.

Development of partially biodegradable foams from PP/HMSPP blends with natural and synthetic polymers; Desenvolvimento de espumas parcialmente biodegradaveis a partir de blendas de PP/HMSPP com polimeros naturais e sinteticos

Energy Technology Data Exchange (ETDEWEB)

Cardoso, Elizabeth Carvalho Leite

2014-07-01

Polymers are used in various application and in different industrial areas providing enormous quantities of wastes in environment. Among diverse components of residues in landfills are polymeric materials, including Polypropylene, which contribute with 20 to 30% of total volume of solid residues. As polymeric materials are immune to microbial degradation, they remain in soil and in landfills as a semi-permanent residue. Environmental concerning in litter reduction is being directed to renewable polymers development for manufacturing of polymeric foams. Foamed polymers are considered future materials, with a wide range of applications; high density structural foams are specially used in civil construction, in replacement of metal, woods and concrete with a final purpose of reducing materials costs. At present development, it was possible the incorporation of PP/HMSPP polymeric matrix blends with sugarcane bagasse, PHB and PLA, in structural foams production. Thermal degradation at 100, 120 and 160 deg C temperatures was not enough to induce biodegradability. Gamma irradiation degradation, at 50, 100, 200 and 500 kGy showed effective for biodegradability induction. Irradiated bagasse blends suffered surface erosion, in favor of water uptake and consequently, a higher biodegradation in bulk structure. (author)

Environmental performance of bio-based and biodegradable plastics: the road ahead.

Science.gov (United States)

Lambert, Scott; Wagner, Martin

2017-11-13

Future plastic materials will be very different from those that are used today. The increasing importance of sustainability promotes the development of bio-based and biodegradable polymers, sometimes misleadingly referred to as 'bioplastics'. Because both terms imply "green" sources and "clean" removal, this paper aims at critically discussing the sometimes-conflicting terminology as well as renewable sources with a special focus on the degradation of these polymers in natural environments. With regard to the former we review innovations in feedstock development (e.g. microalgae and food wastes). In terms of the latter, we highlight the effects that polymer structure, additives, and environmental variables have on plastic biodegradability. We argue that the 'biodegradable' end-product does not necessarily degrade once emitted to the environment because chemical additives used to make them fit for purpose will increase the longevity. In the future, this trend may continue as the plastics industry also is expected to be a major user of nanocomposites. Overall, there is a need to assess the performance of polymer innovations in terms of their biodegradability especially under realistic waste management and environmental conditions, to avoid the unwanted release of plastic degradation products in receiving environments.

Effect of starch types on properties of biodegradable polymer based on thermoplastic starch process by injection molding technique

Directory of Open Access Journals (Sweden)

Yossathorn Tanetrungroj

2015-04-01

Full Text Available In this study effects of different starch types on the properties of biodegradable polymer based on thermoplastic starch (TPS were investigated. Different types of starch containing different contents of amylose and amylopectin were used, i.e. cassava starch, mungbean starch, and arrowroot starch. The TPS polymers were compounded and shaped using an internal mixer and an injection molding machine, respectively. It was found that the amount of amylose and amylopectin contents on native starch influence the properties of the TPS polymer. A high amylose starch of TPMS led to higher strength, hardness, degree of crystallization than the high amylopectin starch of TPCS. In addition, function group analysis by Fourier transforms infrared spectrophotometer, water absorption, and biodegradation by soil burial test were also examined.

Biodegradable shape-memory block co-polymers for fast self-expandable stents.

Science.gov (United States)

Xue, Liang; Dai, Shiyao; Li, Zhi

2010-11-01

Block co-polymers PCTBVs (M(n) of 36,300-65,300 g/mol, T(m) of 39-40 and 142 degrees C) containing hyperbranched three-arm poly(epsilon-caprolactone) (PCL) as switching segment and microbial polyester PHBV as crystallizable hard segment were designed as biodegradable shape-memory polymer (SMP) for fast self-expandable stent and synthesized in 96% yield by the reaction of three-arm PCL-triol (M(n) of 4200 g/mol, T(m) of 47 degrees C) with methylene diphenyl 4,4'-diisocyanate isocynate (MDI) to form the hyperbrached MDI-linked PCL (PTCM; M(n) of 25,400 g/mol and a T(m) of 38 degrees C), followed by further polymerization with PHBV-diol (M(n) of 2200 g/mol, T(m) of 137 and 148 degrees C). The polymers were characterized by (1)H NMR, GPC, DSC, tensile test, and cyclic thermomechanical tensile test. PCTBVs showed desired thermal properties, mechanical properties, and ductile nature. PCTBV containing 25 wt% PHBV (PCTBV-25) demonstrated excellent shape-memory property at 40 degrees C, with R(f) of 94%, R(r) of 98%, and shape recovery within 25s. PCTBV-25 was also shown as a safe material with good biocompatibility by cytotoxicity tests and cell growth experiments. The stent made from PCTBV-25 film showed nearly complete self-expansion at 37 degrees C within only 25 s, which is much better and faster than the best known self-expandable stents. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

Measuring the Biodegradability of Plastic Polymers in Olive-Mill Waste Compost with an Experimental Apparatus

Directory of Open Access Journals (Sweden)

Francesco Castellani

2016-01-01

Full Text Available The use of biodegradable polymers is spreading in agriculture to replace those materials derived from petroleum, thus reducing the environmental concerns. However, to issue a significant assessment, biodegradation rate must be measured in case-specific standardized conditions. In accordance with ISO 14855-1, we designed and used an experimental apparatus to evaluate the biodegradation rate of three biopolymers based on renewable resources, two poly(ε-caprolactone (PCL composites, and a compatibilized polylactic acid and polybutyrate (PLA/PBAT blend. Biodegradation tests were carried out under composting condition using mature olive-mill waste (OMW compost as inoculum. Carbon dioxide emissions were automatically recorded by infrared gas detectors and also trapped in saturated Ba(OH2 solution and evaluated via a standard titration method to check the results. Some of the samples reached more than 80% biodegradation in less than 20 days. Both the experimental apparatus and the OMW compost showed to be suitable for the cases studied.

Biodegradable microfabricated plug-filters for glaucoma drainage devices.

Science.gov (United States)

Maleki, Teimour; Chitnis, Girish; Park, Jun Hyeong; Cantor, Louis B; Ziaie, Babak

2012-06-01

We report on the development of a batch fabricated biodegradable truncated-cone-shaped plug filter to overcome the postoperative hypotony in nonvalved glaucoma drainage devices. Plug filters are composed of biodegradable polymers that disappear once wound healing and bleb formation has progressed past the stage where hypotony from overfiltration may cause complications in the human eye. The biodegradable nature of device eliminates the risks associated with permanent valves that may become blocked or influence the aqueous fluid flow rate in the long term. The plug-filter geometry simplifies its integration with commercial shunts. Aqueous humor outflow regulation is achieved by controlling the diameter of a laser-drilled through-hole. The batch compatible fabrication involves a modified SU-8 molding to achieve truncated-cone-shaped pillars, polydimethylsiloxane micromolding, and hot embossing of biodegradable polymers. The developed plug filter is 500 μm long with base and apex plane diameters of 500 and 300 μm, respectively, and incorporates a laser-drilled through-hole with 44-μm effective diameter in the center.

Radiation Synthesis of Superabsorbent Polymers Based on Natural Polymers

International Nuclear Information System (INIS)

Sen, Murat; Hayrabolulu, Hande

2010-01-01

The objectives of proposed research contract were first synthesize superabsorbent polymers based on natural polymers to be used as disposable diapers and soil conditioning materials in agriculture, horticulture and other super adsorbent using industries. We have planned to use the natural polymers; locust beam gum, tara gum, guar gum and sodium alginate on the preparation of natural superabsorbent polymers(SAP). The aqueous solution of natural polymers and their blends with trace amount of monomer and cross-linking agents will be irradiated in paste like conditions by gamma rays for the preparation of cross-linked superabsorbent systems. The water absorption and deswellling capacity of prepared super adsorbents and retention capacity, absorbency under load, suction power, swelling pressure and pet-rewet properties will be determined. Use of these materials instead of synthetic super absorbents will be examined by comparing the performance of finished products. The experimental studies achieved in the second year of project mainly on the effect of radiation on the chemistry of sodium alginate polymers in different irradiation conditions and structure-property relationship particularly with respect to radiation induced changes on the molecular weight of natural polymers and preliminary studies on the synthesis of natural-synthetic hydride super adsorbent polymers were given in details

Recent trends on gellan gum blends with natural and synthetic polymers: A review.

Science.gov (United States)

Zia, Khalid Mahmood; Tabasum, Shazia; Khan, Muhammad Faris; Akram, Nadia; Akhter, Naheed; Noreen, Aqdas; Zuber, Mohammad

2018-04-01

Gellan gum (GG), a linear negatively charged exopolysaccharide,is biodegradable and non-toxic in nature. It produces hard and translucent gel in the presence of metallic ions which is stable at low pH. However, GG has poor mechanical strength, poor stability in physiological conditions, high gelling temperature and small temperature window.Therefore,it is blended with different polymers such as agar, chitosan, cellulose, sodium alginate, starch, pectin, polyanaline, pullulan, polyvinyl chloride, and xanthan gum. In this article, a comprehensive overview of combination of GG with natural and synthetic polymers/compounds and their applications in biomedical field involving drug delivery system, insulin delivery, wound healing and gene therapy, is presented. It also describes the utilization of GG based materials in food and petroleum industry. All the technical scientific issues have been addressed; highlighting the recent advancement. Copyright © 2017 Elsevier B.V. All rights reserved.

Glycoproteins functionalized natural and synthetic polymers for prospective biomedical applications: A review.

Science.gov (United States)

Tabasum, Shazia; Noreen, Aqdas; Kanwal, Arooj; Zuber, Mohammad; Anjum, Muhammad Naveed; Zia, Khalid Mahmood

2017-05-01

Glycoproteins have multidimensional properties such as biodegradability, biocompatibility, non-toxicity, antimicrobial and adsorption properties; therefore, they have wide range of applications. They are blended with different polymers such as chitosan, carboxymethyl cellulose (CMC), polyvinyl pyrrolidone (PVP), polycaprolactone (PCL), heparin, polystyrene fluorescent nanoparticles (PS-NPs) and carboxyl pullulan (PC) to improve their properties like thermal stability, mechanical properties, resistance to pH, chemical stability and toughness. Considering the versatile charateristics of glycoprotein based polymers, this review sheds light on synthesis and characterization of blends and composites of glycoproteins, with natural and synthetic polymers and their potential applications in biomedical field such as drug delivery system, insulin delivery, antimicrobial wound dressing uses, targeting of cancer cells, development of anticancer vaccines, development of new biopolymers, glycoproteome research, food product and detection of dengue glycoproteins. All the technical scientific issues have been addressed; highlighting the recent advancement. Copyright © 2017 Elsevier B.V. All rights reserved.

Polymer-Layer Silicate Nanocomposites

DEFF Research Database (Denmark)

Potarniche, Catalina-Gabriela

Nowadays, some of the material challenges arise from a performance point of view as well as from recycling and biodegradability. Concerning these aspects, the development of polymer layered silicate nanocomposites can provide possible solutions. This study investigates how to obtain polymer layered...... with a spectacular improvement up to 300 % in impact strength were obtained. In the second part of this study, layered silicate bio-nanomaterials were obtained starting from natural compounds and taking into consideration their biocompatibility properties. These new materials may be used for drug delivery systems...... and as biomaterials due to their high biocompatible properties, and because they have the advantage of being biodegradable. The intercalation process of natural compounds within silicate platelets was investigated. By uniform dispersing of binary nanohybrids in a collagen matrix, nanocomposites with intercalated...

Optical absorption studies on biodegradable PVA/PVP blend polymer electrolyte system

Science.gov (United States)

Basha, S. K. Shahenoor; Reddy, K. Veera Bhadra; Rao, M. C.

2018-05-01

Biodegradable blend polymer electrolytes of PVA/PVP with different wt% ratios of MgCl2.6H2O have been prepared using solution cast technique. Optical absorption studies were carried-out on to the prepared films at room temperature using JASCO V-670 Spectrophotometer in the wavelength region 200-600 nm. Due to the clusters between the vibrations of molecules a broad peak is obtained due to п-п* transition in the wavelength region 310-340 nm.

Synthesis and characterization of an electrolyte system based on a biodegradable polymer

Directory of Open Access Journals (Sweden)

K. Sownthari

2013-06-01

Full Text Available A polymer electrolyte system has been developed using a biodegradable polymer namely poly-ε-caprolactone (PCL in combination with zinc triflate [Zn(CF3SO32] in different weight percentages and characterized during this investigation. Free-standing thin films of varying compositions were prepared by solution casting technique. The successful doping of the polymer has been confirmed by means of Fourier transform infrared spectroscopy (FTIR by analyzing the carbonyl (C=O stretching region of the polymer. The maximum ionic conductivity obtained at room temperature (25°C was found to be 8.8x10–6 S/cm in the case of PCL complexed with 25 wt% Zn(CF3SO32 which is five orders of magnitude higher than that of the pure polymer host material. The increase in amorphous phase with an increase in salt concentration of the prepared polymer electrolyte has also been confirmed from the concordant results obtained from X-ray diffraction (XRD, differential scanning calorimetry (DSC and scanning electron microscopic (SEM analyses. Furthermore, the electrochemical stability window of the prepared polymer electrolyte was found to be 3.7 V. An electrochemical cell has been fabricated based on Zn/MnO2 electrode couple as an application area and its discharge characteristics were evaluated.

A Review on Potentiality of Nano Filler/Natural Fiber Filled Polymer Hybrid Composites

Directory of Open Access Journals (Sweden)

Naheed Saba

2014-08-01

Full Text Available The increasing demand for greener and biodegradable materials leading to the satisfaction of society requires a compelling towards the advancement of nano-materials science. The polymeric matrix materials with suitable and proper filler, better filler/matrix interaction together with advanced and new methods or approaches are able to develop polymeric composites which shows great prospective applications in constructions and buildings, automotive, aerospace and packaging industries. The biodegradability of the natural fibers is considered as the most important and interesting aspects of their utilization in polymeric materials. Nanocomposite shows considerable applications in different fields because of larger surface area, and greater aspect ratio, with fascinating properties. Being environmentally friendly, applications of nanocomposites offer new technology and business opportunities for several sectors, such as aerospace, automotive, electronics, and biotechnology industries. Hybrid bio-based composites that exploit the synergy between natural fibers in a nano-reinforced bio-based polymer can lead to improved properties along with maintaining environmental appeal. This review article intended to present information about diverse classes of natural fibers, nanofiller, cellulosic fiber based composite, nanocomposite, and natural fiber/nanofiller-based hybrid composite with specific concern to their applications. It will also provide summary of the emerging new aspects of nanotechnology for development of hybrid composites for the sustainable and greener environment.

Biodegradable micromechanical sensors

DEFF Research Database (Denmark)

Keller, Stephan Sylvest; Greve, Anders; Schmid, Silvan

of mechanical and thermal properties of polymers. For example, measurements of the resonance frequency of cantilevers were used to characterize thin polymer coatings in various environmental conditions [2]. Also, the influence of humidity on the Young’s modulus of SU-8 was evaluated [3]. However, introduction...... (NIL). Second, we used spray-coating to deposit thin biodegradable films on microcantilevers. Both approaches allowed the determination of the Young’s modulus of the biopolymer. Furthermore, biodegradation by enzymes was investigated....

A sacrificial process for fabrication of biodegradable polymer membranes with submicron thickness.

Science.gov (United States)

Beardslee, Luke A; Stolwijk, Judith; Khaladj, Dimitrius A; Trebak, Mohamed; Halman, Justin; Torrejon, Karen Y; Niamsiri, Nuttawee; Bergkvist, Magnus

2016-08-01

A new sacrificial molding process using a single mask has been developed to fabricate ultrathin 2-dimensional membranes from several biocompatible polymeric materials. The fabrication process is similar to a sacrificial microelectromechanical systems (MEMS) process flow, where a mold is created from a material that can be coated with a biodegradable polymer and subsequently etched away, leaving behind a very thin polymer membrane. In this work, two different sacrificial mold materials, silicon dioxide (SiO2 ) and Liftoff Resist (LOR) were used. Three different biodegradable materials; polycaprolactone (PCL), poly(lactic-co-glycolic acid) (PLGA), and polyglycidyl methacrylate (PGMA), were chosen as model polymers. We demonstrate that this process is capable of fabricating 200-500 nm thin, through-hole polymer membranes with various geometries, pore-sizes and spatial features approaching 2.5 µm using a mold fabricated via a single contact photolithography exposure. In addition, the membranes can be mounted to support rings made from either SU8 or PCL for easy handling after release. Cell culture compatibility of the fabricated membranes was evaluated with human dermal microvascular endothelial cells (HDMECs) seeded onto the ultrathin porous membranes, where the cells grew and formed confluent layers with well-established cell-cell contacts. Furthermore, human trabecular meshwork cells (HTMCs) cultured on these scaffolds showed similar proliferation as on flat PCL substrates, further validating its compatibility. All together, these results demonstrated the feasibility of our sacrificial fabrication process to produce biocompatible, ultra-thin membranes with defined microstructures (i.e., pores) with the potential to be used as substrates for tissue engineering applications. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 104B: 1192-1201, 2016. © 2015 Wiley Periodicals, Inc.

Optimization of disintegration behavior of biodegradable poly (hydroxy butanoic acid) copolymer mulch films in soil environment

Science.gov (United States)

Mahajan, Viabhav

Biodegradation of polymeric films used for mulch film applications in agriculture not only eliminates problems of sorting out and disposal of plastics films, but also ensures increased yields in crop growth and cost reduction. One such polymer which is completely biodegradable in the soil is poly 3-hydroxy butanoic acid copolymer, which is a promising alternative to non-biodegradable incumbent polyethylene mulch films. The purpose of mulch film made of poly 3-hydroxy butanoic acid copolymers is to sustain itself during the crop growth and disintegrate and eventually biodegrade back to nature after the crop cycle is over. The disintegration phase of the biodegradation process was evaluated for poly 3-hydroxy butanoic acid copolymer incorporated with no additive, antimicrobial additives, varying amount of crystallinities, another biodegradable polymer, and in different soils, with or without varying soil moisture content. The tools used for quantification were weight loss and visual observation. The test method was standardized using repeatability tests. The onset of disintegration was optimized with addition of right anti-microbial additives, higher crystallinity of film, blending with other biodegradable polymers, compared to virgin poly 3-hydroxy butanoic acid copolymer film. The onset of disintegration time was reduced when soil moisture content was reduced. After the onset of disintegration, the polymer film was physically and mechanically deteriorated, withering away in soil, which is possible to tailor with the crop growth cycle.

Natural-Synthetic Hybrid Polymers Developed via Electrospinning: The Effect of PET in Chitosan/Starch System

Science.gov (United States)

Espíndola-González, Adolfo; Martínez-Hernández, Ana Laura; Fernández-Escobar, Francisco; Castaño, Victor Manuel; Brostow, Witold; Datashvili, Tea; Velasco-Santos, Carlos

2011-01-01

Chitosan is an amino polysaccharide found in nature, which is biodegradable, nontoxic and biocompatible. It has versatile features and can be used in a variety of applications including films, packaging, and also in medical surgery. Recently a possibility to diversify chitosan properties has emerged by combining it with synthetic materials to produce novel natural-synthetic hybrid polymers. We have studied structural and thermophysical properties of chitosan + starch + poly(ethylene terephthalate) (Ch + S + PET) fibers developed via electrospinning. Properties of these hybrids polymers are compared with extant chitosan containing hybrids synthesized by electrospinning. Molecular interactions and orientation in the fibers are analyzed by infrared and Raman spectroscopies respectively, morphology by scanning electron microscopy and thermophysical properties by thermogravimetric analysis and differential scanning calorimetry. Addition of PET to Ch + S systems results in improved thermal stability at elevated temperatures. PMID:21673930

Preparation of Natural and Synthetic Porous Biodegradable ...

Indian Academy of Sciences (India)

First page Back Continue Last page Overview Graphics. Preparation of Natural and Synthetic Porous Biodegradable Scaffolds for Infected Wounds. Characterised for their physical properties, pore size and release kinetics. Release kinetics of bioactive molecules (antibiotics) in a controlled fashion. Release pattern of the ...

Natural polymers: an overview

CSIR Research Space (South Africa)

John, MJ

2012-08-01

Full Text Available The scarcity of natural polymers during the world war years led to the development of synthetic polymers like nylon, acrylic, neoprene, styrene-butadiene rubber (SBR) and polyethylene. The increasing popularity of synthetic polymers is partly due...

ANAEROBIC BIODEGRADATION OF A BIODEGRADABLE MATERIAL UNDER ANAEROBIC - THERMOPHILIC DIGESTION

Directory of Open Access Journals (Sweden)

RICARDO CAMACHO-MUÑOZ

2014-12-01

Full Text Available This paper dertermined the anaerobic biodegradation of a polymer obtained by extrusion process of native cassava starch, polylactic acid and polycaprolactone. Initially a thermophilic - methanogenic inoculum was prepared from urban solid waste. The gas final methane concentration and medium’s pH reached values of 59,6% and 7,89 respectively. The assay assembly was carried out according ASTM D5511 standard. The biodegradation percent of used materials after 15 day of digestion were: 77,49%, 61,27%, 0,31% for cellulose, sample and polyethylene respectively. Due cellulose showed biodegradation levels higher than 70% it’s deduced that the inoculum conditions were appropriate. A biodegradation level of 61,27%, 59,35% of methane concentration in sample’s evolved gas and a medium’s finale pH of 7,71 in sample’s vessels, reveal the extruded polymer´s capacity to be anaerobically degraded under thermophilic- high solid concentration conditions.

Investigating the crystal growth behavior of biodegradable polymer blend thin films using in situ atomic force microscopy

CSIR Research Space (South Africa)

Malwela, T

2014-01-01

Full Text Available This article reports the crystal growth behavior of biodegradable polylactide (PLA)/poly[(butylene succinate)-co-adipate] (PBSA) blend thin films using atomic force microscopy (AFM). Currently, polymer thin films have received increased research...

Biodegradation of NR Latex-based Materials via a Carbon Dioxide Evolution Method

Directory of Open Access Journals (Sweden)

F. M. S. Shabinah

2017-12-01

Full Text Available NR as a natural polymer has biodegradable characteristics and their existence was examined using CO2 evolution methods. The CO2 molecule produced by micro-organism metabolisms in the degradation system was quantified using a conventional acidimetric method. An aerobic system was determined as most suitable condition to be examined under this method. The presence of O2 in the system would help micro-organisms to destabilize the natural polymer. The material of LATZ, HA film and NR gloves showed significant weight loss and were able to produce CO2 evolution curves after 45 days in the biodegradation system compared to synthetic polyisoprene films. Gel permeation chromatography, fourier transform infrared spectroscopy and scanning electron micrograph were used to characterize the degraded sample at molecular and physical levels.

Natural gums and modified natural gums as sustained-release carriers.

Science.gov (United States)

Bhardwaj, T R; Kanwar, M; Lal, R; Gupta, A

2000-10-01

Although natural gums and their derivatives are used widely in pharmaceutical dosage forms, their use as biodegradable polymeric materials to deliver bioactive agents has been hampered by the synthetic materials. These natural polysaccharides do hold advantages over the synthetic polymers, generally because they are nontoxic, less expensive, and freely available. Natural gums can also be modified to have tailor-made materials for drug delivery systems and thus can compete with the synthetic biodegradable excipients available in the market. In this review, recent developments in the area of natural gums and their derivatives as carriers in the sustained release of drugs are explored.

Biodegradation of hydrocarbon compounds in Agbabu natural bitumen

African Journals Online (AJOL)

Infrared spectral changes and gravimetric analysis from the preliminary biodegradability study carried out on Agbabu Natural Bitumen showed the vulnerability of the bitumen to some bacteria: Pseudomonas putrefaciens, Pseudomonas nigrificans, Bacillus licheniformis, Pseudomonas fragi and Achromobacter aerogenes.

Ecological concepts in recent polymer technology. Part4. Eco-friendly water-absorbing polymer; Kankyo ni chowa shita kyusuisei kobunshi

Energy Technology Data Exchange (ETDEWEB)

Kunioka, M.

1997-07-01

As an application example of water-absorbing polymers with biodegradability, it was expected to be applied to soil improvement agents used in planting trees in deserts, besides physiological napkins, paper diapers and medical materials. In this paper, water-absorbing polymers with biodegradability such as natural polymers, petroleum-made polymers and polymers synthesized by radiation cross-linking and chemical cross-linking were introduced. Moreover, a kind of water-absorbing polymers developed by the authors, made from polyamino acid synthesized by microbes, was introduced. In the method developed by the authors, the cross-linking structure could be made by combining PGA carboxyl groups and various amino groups of diamine using carbimide with water solubility. As for this method, all of reactions could be conducted in water and catalytic replacement was not necessary, moreover, hydrogel with the water-absorbing rate of 200 to 1500 times could be produced. 44 refs., 3 figs., 1 tab.

Obtaining and characterization of a biodegradable polymer starting from the tapioca starch

International Nuclear Information System (INIS)

Ruiz Aviles, Gladys

2006-01-01

This study focuses on the preparation of tapioca starch biodegradable polymer, processed by blends of starch modified with glycerin and water as plasticizers, by using roll mill and a single-screw extruder in the process. During extrusion, there is a series of variables to control namely: the barrel temperature profile, screw torque and screw rotation speed. Tensile test, differential scanning calorimetric (DSC), thermogravimetric analysis (TGA), Fourier transformer infrared spectroscopy (FTIR) and morphology were used in the process

Numerical study on injection parameters optimization of thin wall and biodegradable polymers parts

Science.gov (United States)

Santos, C.; Mendes, A.; Carreira, P.; Mateus, A.; Malça, C.

2017-07-01

Nowadays, the molds industry searches new markets, with diversified and added value products. The concept associated to the production of thin walled and biodegradable parts mostly manufactured by injection process has assumed a relevant importance due to environmental and economic factors. The growth of a global consciousness about the harmful effects of the conventional polymers in our life quality associated with the legislation imposed, become key factors for the choice of a particular product by the consumer. The target of this work is to provide an integrated solution for the injection of parts with thin walls and manufactured using biodegradable materials. This integrated solution includes the design and manufacture processes of the mold as well as to find the optimum values for the injection parameters in order to become the process effective and competitive. For this, the Moldflow software was used. It was demonstrated that this computational tool provides an effective responsiveness and it can constitute an important tool in supporting the injection molding of thin-walled and biodegradable parts.

Nature's Mechanisms for Tough, Self-healing Polymers and Polymer Adhesives

Science.gov (United States)

Hansma, Paul

2007-03-01

Spider silk^2 and the natural polymer adhesives in abalone shells^3 and bone^4,5 can give us insights into nature's mechanisms for tough, self-healing polymers and polymer adhesives. The natural polymer adhesives in biomaterials have been optimized by evolution. An optimized polymer adhesive has five characteristics. 1) It holds together the strong elements of the composite. 2) It yields just before the strong elements would otherwise break. 3) It dissipates large amounts of energy as it yields. 4) It self heals after it yields. 5) It takes just a few percent by weight. Both natural polymer adhesives and silk rely on sacrificial bonds and hidden length for toughness and self-healing.^6 A relatively large energy, of order 100eV, is required to stretch a polymer molecule after a weak bond, a sacrificial bond, breaks and liberates hidden length, which was previously hidden, typically in a loop or folded domain, from whatever was stretching the polymer. The bond is called sacrificial if it breaks at forces well below the forces that could otherwise break the polymer backbone, typically greater than 1nN. In many biological cases, the breaking of sacrificial bonds has been found to be reversible, thereby also providing a ``self-healing'' property to the material.^2-4 Individual polymer adhesive molecules based on sacrificial bonds and hidden length can supply forces of order 300pN over distances of 100s of nanometers. Model calculations show that a few percent by weight of adhesives based on these principles could be optimized adhesives for high performance composite materials including nanotube and graphene sheet composites. ^2N. Becker, E. Oroudjev, S. Mutz et al., Nature Materials 2 (4), 278 (2003). ^3B. L. Smith, T. E. Schaffer, M. Viani et al., Nature 399 (6738), 761 (1999). ^4J. B. Thompson, J. H. Kindt, B. Drake et al., Nature 414 (6865), 773 (2001). ^5G. E. Fantner, T. Hassenkam, J. H. Kindt et al., Nature Materials 4, 612 (2005). ^6G. E. Fantner, E. Oroudjev, G

New biocomposites based on bioplastic flax fibers and biodegradable polymers.

Science.gov (United States)

Wróbel-Kwiatkowska, Magdalena; Czemplik, Magdalena; Kulma, Anna; Zuk, Magdalena; Kaczmar, Jacek; Dymińska, Lucyna; Hanuza, Jerzy; Ptak, Maciej; Szopa, Jan

2012-01-01

A new generation of entirely biodegradable and bioactive composites with polylactic acid (PLA) or poly-ε-caprolactone (PCL) as the matrix and bioplastic flax fibers as reinforcement were analyzed. Bioplastic fibers contain polyhydroxybutyrate and were obtained from transgenic flax. Biochemical analysis of fibers revealed presence of several antioxidative compounds of hydrophilic (phenolics) and hydrophobic [cannabidiol (CBD), lutein] nature, indicating their high antioxidant potential. The presence of CBD and lutein in flax fibers is reported for the first time. FTIR analysis showed intermolecular hydrogen bonds between the constituents in composite PLA+flax fibers which were not detected in PCL-based composite. Mechanical analysis of prepared composites revealed improved stiffness and a decrease in tensile strength. The viability of human dermal fibroblasts on the surface of composites made of PLA and transgenic flax fibers was the same as for cells cultured without composites and only slightly lower (to 9%) for PCL-based composites. The amount of platelets and Escherichia coli cells aggregated on the surface of the PLA based composites was significantly lower than for pure polymer. Thus, composites made of PLA and transgenic flax fibers seem to have bacteriostatic, platelet anti-aggregated, and non-cytotoxic effect. Copyright © 2012 American Institute of Chemical Engineers (AIChE).

Imaging the intracellular degradation of biodegradable polymer nanoparticles

Directory of Open Access Journals (Sweden)

Anne-Kathrin Barthel

2014-10-01

Full Text Available In recent years, the development of smart drug delivery systems based on biodegradable polymeric nanoparticles has become of great interest. Drug-loaded nanoparticles can be introduced into the cell interior via endocytotic processes followed by the slow release of the drug due to degradation of the nanoparticle. In this work, poly(L-lactic acid (PLLA was chosen as the biodegradable polymer. Although common degradation of PLLA has been studied in various biological environments, intracellular degradation processes have been examined only to a very limited extent. PLLA nanoparticles with an average diameter of approximately 120 nm were decorated with magnetite nanocrystals and introduced into mesenchymal stem cells (MSCs. The release of the magnetite particles from the surface of the PLLA nanoparticles during the intracellular residence was monitored by transmission electron microscopy (TEM over a period of 14 days. It was demonstrated by the release of the magnetite nanocrystals from the PLLA surface that the PLLA nanoparticles do in fact undergo degradation within the cell. Furthermore, even after 14 days of residence, the PLLA nanoparticles were found in the MSCs. Additionally, the ultrastructural TEM examinations yield insight into the long term intercellular fate of these nanoparticles. From the statistical analysis of ultrastructural details (e.g., number of detached magnetite crystals, and the number of nanoparticles in one endosome, we demonstrate the importance of TEM studies for such applications in addition to fluorescence studies (flow cytometry and confocal laser scanning microscopy.

Microencapsulation of superoxide dismutase into biodegradable microparticles by spray-drying.

Science.gov (United States)

Youan, Bi-Botti Célestin

2004-01-01

The aim of this work was to encapsulate superoxide dismutase (SOD) into biodegradable microparticles by spray-drying technique. The nature of the organic solvent to dissolve the polymer, the method of incorporation of the drug in the organic phase (with or without a surfactant, namely sucrose ester of HLB = 6), the surfactant/polymer ratio, and the nature of the biodegradable polyesters were investigated as formulation variables. The polyesters investigated as matrix were poly(epsilon-caprolactone) (PCL), poly(d, l, lactide-co-glycolide) (PLG-RG756), and poly(d, l-lactide) (PLA-R207) of respective molecular weight 78.2 kDa, 84.8 kDa, and 199.8 kDa. At surfactant/polymer ratio of 1/10, the SOD-retained enzymatic activities were higher (> 95%) for PLG-RG756 and PLA-R207 but relatively lower for the PCL (approximately 85%) probably due to the PCL relatively higher hydrophobicity. The obtained microparticles exhibited average volume mean diameter of 4-10 microm, the smaller for PCL and the larger for PLG-RG756 polymeric matrix. The in vitro release profile showed that SOD was completely (100%) released from PLA-R207 in 48 hr and from PLG-RG756 and PCL within 72 hr. These results showed that spray-drying with incorporation of surfactant such as sucrose ester may efficiently encapsulate SOD into biodegradable microparticles. Such formulations may improve the bioavailability of SOD and similar biopharmaceuticals.

High performance nature of biodegradable polymeric nanocomposites for oil-well drilling fluids

Directory of Open Access Journals (Sweden)

Tarek M. Madkour

2016-06-01

Full Text Available Multi-walled carbon nanotube (MWCNT and graphene nanoplatelet reinforced thermoplastic poly(lactic acid (PLA biodegradable nanocomposites were designed and prepared using solution casting techniques. The prepared biodegradable polymers are expected to provide an environmentally friendly alternative to petroleum-based polymers. Both nanocomposite systems exhibited better thermal stability and improved mechanical performance over the unreinforced polymer exhibiting excellent strength and degradability. The addition of graphene nanofiller in varied amounts was aimed to enhance the thermal and mechanical properties of the nanocomposites even further and incorporate the outstanding characteristics of graphene nanoplatelets into the nanocomposites. The polymeric nanocomposites showed also superior advantages for oil drilling relevances, automotive lubricating purposes, membrane technology and food packaging. Scanning electron microscopy images indicated a homogeneous dispersion of the nanofiller within the polymeric matrix at low filler loadings and a cluster formation at higher loadings that could be responsible for the polymeric matrix movement restrictions. The enthalpy of mixing (the polymer and the nanofiller measured could explain the cause of the repulsive interactions between the nanoparticles and the polymeric chains, which created an additional excluded volume that the polymeric segments were restricted to occupy, thus forcing the conformational characteristics of the polymeric chains to deviate away from those of the bulk chains. The prepared polymeric nano composites (poly lactic acid carbon nano tube and poly lactic acid graphene nanoplatelets were utilized in the formulation of oil-base mud as a viscosifier. The rheological, filtration properties and electrical stability of the oil based mud formulation with the new polymeric nanocomposite were studied and the result compared to the oil-based mud formulation with commercial viscosifier.

Biodegradable polylactic acid polymer with nisin for use in antimicrobial food packaging.

Science.gov (United States)

Jin, T; Zhang, H

2008-04-01

Biodegradable polylactic acid (PLA) polymer was evaluated for its application as a material for antimicrobial food packaging. PLA films were incorporated with nisin to for control of foodborne pathogens. Antimicrobial activity of PLA/nisin films against Listeria monocytogenes, Escherichia coli O157:H7, and Salmonella Enteritidis were evaluated in culture media and liquid foods (orange juice and liquid egg white). Scanned electron micrograph and confocal laser microscopy revealed that nisin particles were evenly distributed in PLA polymer matrix on the surface and inside of the PLA/nisin films. PLA/nisin significantly inhibited growth of L. monocytogenes in culture medium and liquid egg white. The greatest inhibition occurred at 24 h when the cell counts of L. monocytogenes in the PLA/nisin samples were 4.5 log CFU/mL less than the controls. PLA/nisin reduced the cell population of E. coli O157:H7 in orange juice from 7.5 to 3.5 log at 72 h whereas the control remained at about 6 log CFU/mL. PLA/nisin treatment resulted in a 2 log reduction of S. Enteritidis in liquid egg white at 24 degrees C. After 21 d at 4 degrees C the S. Enteritidis population from PLA/nisin treated liquid egg white (3.5 log CFU/mL) was significantly less than the control (6.8 log CFU/mL). E. coli O157:H7 in orange juice was more sensitive to PLA/nisin treatments than in culture medium. The results of this research demonstrated the retention of nisin activity when incorporated into the PLA polymer and its antimicrobial effectiveness against foodborne pathogens. The combination of a biopolymer and natural bacteriocin has potential for use in antimicrobial food packaging.

Biodegradability of plastics.

Science.gov (United States)

Tokiwa, Yutaka; Calabia, Buenaventurada P; Ugwu, Charles U; Aiba, Seiichi

2009-08-26

Plastic is a broad name given to different polymers with high molecular weight, which can be degraded by various processes. However, considering their abundance in the environment and their specificity in attacking plastics, biodegradation of plastics by microorganisms and enzymes seems to be the most effective process. When plastics are used as substrates for microorganisms, evaluation of their biodegradability should not only be based on their chemical structure, but also on their physical properties (melting point, glass transition temperature, crystallinity, storage modulus etc.). In this review, microbial and enzymatic biodegradation of plastics and some factors that affect their biodegradability are discussed.

Synthesis of biodegradable styrene copolymers

OpenAIRE

Gevers, Dries; Kobben, Stephan; Junkers, Tanja; Copinet, Alain; Buntinx, Mieke; Peeters, Roos

2017-01-01

Polystyrene (PS), a versatile polymer with many applications (e.g. packaging) representing about 10% of the total annual polymer consumption, shows practically no biodegradability. In this study a styrene (ST) based copolymer is synthesized and examined regarding its ability to degrade in a composting test. As second monomer, to introduce biodegradable ester groups, 5,6-benzo-2-metylene-dioxepane (BMDO) has been used in radical copolymerization reactions performed in inert and stirred 10 m...

METHOD FOR PROVIDING SHAPED BIODEGRADABLE AND ELASTOMERIC STRUCTURES OF (CO) POLYMERS OF 1,3-TRIMETHYLENE CARBONATE (TMC), SHAPED BIODEGRADABLE AND ELASTOMERIC STRUCTURES, AND THE USE OF THESE STRUCTURES

NARCIS (Netherlands)

Grijpma, D.W.; Pêgo, A.P.; Feijen, Jan

2004-01-01

The present invention relates to methods for providing shaped biodegradable and elastomeric structures of (co)polymers of 1,3­trimethylene carbonate (TMC) with improved (mechanical) properties which can be used for tissue or tissue component support, generation or regeneration. Such shaped

[New polymer-drug systems based on natural and synthetic polymers].

Science.gov (United States)

Racoviţă, Stefania; Vasiliu, Silvia; Foia, Liliana

2010-01-01

The great versatility of polymers makes them very useful in the biomedical and pharmaceutical fields. The combination of natural and synthetic polymers leads to new materials with tailored functional properties. The aim of this work consists in the preparation of new drug delivery system based on chitosan (natural polymer) and polybetaines (synthetic polymers), by a simple process, well known in the literature as complex coacervation methods. Also, the adsorption and release studies of two antibiotics as well as the preservation of their bactericidal capacities were performed.

Proceedings of the Takasaki symposium on radiation application of natural polymers in Asia

International Nuclear Information System (INIS)

Kume, Tamikazu; Maekawa, Yasunari

2002-03-01

This Takasaki symposium was annually held as the 3rd meeting for radiation processing of natural polymers through research cooperation among Asian countries. The symposium includes the presentations of research outcomes on radiation processing of starches, silk proteins and marine carbohydrates. In the researches of starch and cellulose, radiation crosslinking of biodegradable polysaccharides was achieved by modifying it to be water-soluble paste, showing the wide range of its application to wound dressing and biodegradable plastics. In silk protein researches, pulverization and water-solubilization of the irradiated silk proteins and its antibacterial properties were reported. In the researches of marine carbohydrates, it was reported that radiation-degraded chitosan and alginate showed promotion effects for plant growth, enhancement of antibacterial properties, and capability to be applied for bioadhesive materials. In addition, in estimation of economic scale of radiation application, comparisons between Japan and U.S. in medical, agricultural and industrial fields were introduced. Many domestic and foreign attendants were very interested in reports and exchanged their opinions actively. Radiation application of natural polymers are the most important subjects from the view points of resource recycling and environment protection and are good agreement with the needs of Asian countries. Outcomes of this symposium are expected to contribute the progress in radiation applications in south Asian countries as well as Japan. In the symposium we had the 63 participants consisted of 16 foreign researchers from not only bilaterally cooperated Malaysia, Thailand and Vietnam, but also Indonesia and China, 28 from domestic universities, governmental institutes and companies, and 32 from JAERI. This proceeding compiles the invited and contributed papers. The 22 of the presented papers are indexed individually. (J.P.N.)

Morphology and transport in biodegradable polymer compositions based on poly(3-hydroxybutyrate) and polyamide 54C

Energy Technology Data Exchange (ETDEWEB)

Zhul' kina, A. L.; Ivantsova, E. L.; Filatova, A. G.; Kosenko, R. Yu.; Gumargalieva, K. Z.; Iordanskii, A. L., E-mail: iordan@chph.ras.ru [Russian Academy of Sciences, Semenov Institute of Chemical Physics (Russian Federation)

2009-05-15

Complex investigation of the equilibrium sorption of water, diffusive transport of antiseptic, and morphology of mixed compositions based on polyoxybutirate and polyamide resin 54C has been performed to develop and analyze new biodegradable polymer compositions for controlled release of medicinal substances. Samples of mixtures were prepared by two methods: pressing under pressure and solvent evaporation from a polymer solution. The samples were compared and their morphology was analyzed by scanning electron microscopy. It is shown that the component ratio in the obtained mixtures affects their morphological, transport, and sorption characteristics.

Morphology and transport in biodegradable polymer compositions based on poly(3-hydroxybutyrate) and polyamide 54C

International Nuclear Information System (INIS)

Zhul'kina, A. L.; Ivantsova, E. L.; Filatova, A. G.; Kosenko, R. Yu.; Gumargalieva, K. Z.; Iordanskii, A. L.

2009-01-01

Complex investigation of the equilibrium sorption of water, diffusive transport of antiseptic, and morphology of mixed compositions based on polyoxybutirate and polyamide resin 54C has been performed to develop and analyze new biodegradable polymer compositions for controlled release of medicinal substances. Samples of mixtures were prepared by two methods: pressing under pressure and solvent evaporation from a polymer solution. The samples were compared and their morphology was analyzed by scanning electron microscopy. It is shown that the component ratio in the obtained mixtures affects their morphological, transport, and sorption characteristics.

Optical and thermal properties in ultrafast laser surface nanostructuring on biodegradable polymer

Science.gov (United States)

Yada, Shuhei; Terakawa, Mitsuhiro

2015-03-01

We investigate the effect of optical and thermal properties in laser-induced periodic surface structures (LIPSS) formation on a poly-L-lactic acid (PLLA), a biodegradable polymer. Surface properties of biomaterials are known to be one of the key factors in tissue engineering. Methods to process biomaterial surfaces have been studied widely to enhance cell adhesive and anisotropic properties. LIPSS formation has advantages in a dry processing which is able to process complex-shaped surfaces without using a toxic chemical component. LIPSS, however, was difficult to be formed on PLLA due to its thermal and optical properties compared to other polymers. To obtain new perspectives in effect of these properties above, LIPSS formation dependences on wavelength, pulse duration and repetition rate have been studied. At 800 nm of incident wavelength, high-spatial frequency LIPSS (HSFL) was formed after applying 10000 femtosecond pulses at 1.0 J/cm2 in laser fluence. At 400 nm of the wavelength, HSFL was formed at fluences higher than 0.20 J/cm2 with more than 3000 pulses. Since LIPSS was less formed with lower repetition rate, certain heat accumulation may be required for LIPSS formation. With the pulse duration of 2.0 ps, higher laser fluence as well as number of pulses compared to the case of 120 fs was necessary. This indicates that multiphoton absorption process is essential for LIPSS formation. Study on biodegradation modification was also performed.

Effect of cold drawing on mechanical properties of biodegradable fibers.

Science.gov (United States)

La Mantia, Francesco Paolo; Ceraulo, Manuela; Mistretta, Maria Chiara; Morreale, Marco

2017-01-26

Biodegradable polymers are currently gaining importance in several fields, because they allow mitigation of the impact on the environment related to disposal of traditional, nonbiodegradable polymers, as well as reducing the utilization of oil-based sources (when they also come from renewable resources). Fibers made of biodegradable polymers are of particular interest, though, it is not easy to obtain polymer fibers with suitable mechanical properties and to tailor these to the specific application. The main ways to tailor the mechanical properties of a given biodegradable polymer fiber are based on crystallinity and orientation control. However, crystallinity can only marginally be modified during processing, while orientation can be controlled, either during hot drawing or cold stretching. In this paper, a systematic investigation of the influence of cold stretching on the mechanical and thermomechanical properties of fibers prepared from different biodegradable polymer systems was carried out. Rheological and thermal characterization helped in interpreting the orientation mechanisms, also on the basis of the molecular structure of the polymer systems. It was found that cold drawing strongly improved the elastic modulus, tensile strength and thermomechanical resistance of the fibers, in comparison with hot-spun fibers. The elastic modulus showed higher increment rates in the biodegradable systems upon increasing the draw ratio.

Activated sludge is a potential source for production of biodegradable plastics from wastewater.

Science.gov (United States)

Khardenavis, A; Guha, P K; Kumar, M S; Mudliar, S N; Chakrabarti, T

2005-05-01

Increased utilization of synthetic plastics caused severe environmental pollution due to their non-biodegradable nature. In the search for environmentally friendly materials to substitute for conventional plastics, different biodegradable plastics have been developed by microbial fermentations. However, limitations of these materials still exist due to high cost. This study aims at minimization of cost for the production of biodegradable plastics P(3HB) and minimization of environmental pollution. The waste biological sludge generated at wastewater treatment plants is used for the production of P(3HB) and wastewater is used as carbon source. Activated sludge was induced by controlling the carbon: nitrogen ratio to accumulate storage polymer. Initially polymer accumulation was studied by using different carbon and nitrogen sources. Maximum accumulation of polymer was observed with carbon source acetic acid and diammonium hydrogen phosphate (DAHP) as nitrogen source. Further studies were carried out to optimize the carbon: nitrogen ratios using acetic acid and DAHP. A maximum of 65.84% (w/w) P(3HB) production was obtained at C/N ratio of 50 within 96 hours of incubation.

Research regarding biodegradable properties of food polymeric products under microorganism activity

Science.gov (United States)

Opran, Constantin; Lazar, Veronica; Fierascu, Radu Claudiu; Ditu, Lia Mara

2018-02-01

Aim of this research is the structural analysis by comparison of the biodegradable properties of two polymeric products made by non-biodegradable polymeric material (polypropylene TIPPLEN H949 A) and biodegradable polymeric material (ECOVIO IS 1335), under microorganism activity in order to give the best solution for the manufacture of food packaging biodegradable products. It presents the results of experimental determinations on comparative analysis of tensile strength for the two types of polymers. The sample weight variations after fungal biodegradation activity revealed that, after 3 months, there are no significant changes in polymeric substratum for non-biodegradable polymeric. The microscopically analysis showed that the fungal filaments did not strongly adhered on the non-biodegradable polymeric material, instead, both filamentous fungi strains adhered and covered the surface of the biodegradable sample with germinated filamentous conidia. The spectral analysis of polymer composition revealed that non-biodegradable polymer polypropylene spectra are identical for control and for samples that were exposed to fungal activity, suggesting that this type of sample was not degraded by the fungi strains. Instead, for biodegradable polymer sample, it was observed significant structural changes across multiple absorption bands, suggesting enzyme activity manifested mainly by Aspergillus niger strain. Structural analysis of interdisciplinary research results, lead, to achieving optimal injection molded technology emphasizing technological parameters, in order to obtain food packaging biodegradable products.

Biodegradable elastomers for biomedical applications and regenerative medicine

NARCIS (Netherlands)

Bat, Erhan; Zhang, Zheng; Feijen, Jan; Grijpma, Dirk W.; Poot, Andre A.

Synthetic biodegradable polymers are of great value for the preparation of implants that are required to reside only temporarily in the body. The use of biodegradable polymers obviates the need for a second surgery to remove the implant, which is the case when a nondegradable implant is used. After

Microbial Enzymatic Degradation of Biodegradable Plastics.

Science.gov (United States)

Roohi; Bano, Kulsoom; Kuddus, Mohammed; Zaheer, Mohammed R; Zia, Qamar; Khan, Mohammed F; Ashraf, Ghulam Md; Gupta, Anamika; Aliev, Gjumrakch

2017-01-01

The renewable feedstock derived biodegradable plastics are important in various industries such as packaging, agricultural, paper coating, garbage bags and biomedical implants. The increasing water and waste pollution due to the available decomposition methods of plastic degradation have led to the emergence of biodegradable plastics and biological degradation with microbial (bacteria and fungi) extracellular enzymes. The microbes utilize biodegradable polymers as the substrate under starvation and in unavailability of microbial nutrients. Microbial enzymatic degradation is suitable from bioremediation point of view as no waste accumulation occurs. It is important to understand the microbial interaction and mechanism involved in the enzymatic degradation of biodegradable plastics under the influence of several environmental factors such as applied pH, thermo-stability, substrate molecular weight and/or complexity. To study the surface erosion of polymer film is another approach for hydrolytic degradation characteristion. The degradation of biopolymer is associated with the production of low molecular weight monomer and generation of carbon dioxide, methane and water molecule. This review reported the degradation study of various existing biodegradable plastics along with the potent degrading microbes (bacteria and fungi). Patents available on plastic biodegradation with biotechnological significance is also summarized in this paper. This paper assesses that new disposal technique should be adopted for the degradation of polymers and further research is required for the economical production of biodegradable plastics along with their enzymatic degradation. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Dual Functional Nanocarrier for Cellular Imaging and Drug Delivery in Cancer Cells Based on π-Conjugated Core and Biodegradable Polymer Arms.

Science.gov (United States)

Kulkarni, Bhagyashree; Surnar, Bapurao; Jayakannan, Manickam

2016-03-14

Multipurpose polymer nanoscaffolds for cellular imaging and delivery of anticancer drug are urgently required for the cancer therapy. The present investigation reports a new polymer drug delivery concept based on biodegradable polycaprolactone (PCL) and highly luminescent π-conjugated fluorophore as dual functional nanocarrier for cellular imaging and delivery vehicles for anticancer drug to cancer cells. To accomplish this goal, a new substituted caprolactone monomer was designed, and it was subjected to ring opening polymerization using a blue luminescent bishydroxyloligo-phenylenevinylene (OPV) fluorophore as an initiator. A series of A-B-A triblock copolymer building blocks with a fixed OPV π-core and variable chain biodegradable PCL arm length were tailor-made. These triblocks self-assembled in organic solvents to produce well-defined helical nanofibers, whereas in water they produced spherical nanoparticles (size ∼150 nm) with blue luminescence. The hydrophobic pocket of the polymer nanoparticle was found to be an efficient host for loading water insoluble anticancer drug such as doxorubicin (DOX). The photophysical studies revealed that there was no cross-talking between the OPV and DOX chromophores, and their optical purity was retained in the nanoparticle assembly for cellular imaging. In vitro studies revealed that the biodegradable PCL arm was susceptible to enzymatic cleavage at the intracellular lysosomal esterase under physiological conditions to release the loaded drugs. The nascent nanoparticles were found to be nontoxic to cancer cells, whereas the DOX-loaded nanoparticles accomplished more than 80% killing in HeLa cells. Confocal microscopic analysis confirmed the cell penetrating ability of the blue luminescent polymer nanoparticles and their accumulation preferably in the cytoplasm. The DOX loaded red luminescent polymer nanoparticles were also taken up by the cells, and the drug was found to be accumulated at the perinuclear environment

Biodegradability of Plastics

Directory of Open Access Journals (Sweden)

Yutaka Tokiwa

2009-08-01

Full Text Available Plastic is a broad name given to different polymers with high molecular weight, which can be degraded by various processes. However, considering their abundance in the environment and their specificity in attacking plastics, biodegradation of plastics by microorganisms and enzymes seems to be the most effective process. When plastics are used as substrates for microorganisms, evaluation of their biodegradability should not only be based on their chemical structure, but also on their physical properties (melting point, glass transition temperature, crystallinity, storage modulus etc.. In this review, microbial and enzymatic biodegradation of plastics and some factors that affect their biodegradability are discussed.

Modified hydrotalcite-like compounds as active fillers of biodegradable polymers for drug release and food packaging applications.

Science.gov (United States)

Costantino, Umberto; Nocchetti, Morena; Tammaro, Loredana; Vittoria, Vittoria

2012-11-01

This review treats the recent patents and related literature, mainly from the Authors laboratories, on biomedical and food packaging applications of nano-composites constituted of biodegradable polymers filled with micro or nano crystals of organically modified Layered Double Hydroxides of Hydrotalcite type. After a brief outline of the chemical and structural aspects of Hydrotalcite-like compounds (HTlc) and of their manipulation via intercalation of functional molecular anions to obtain materials for numerous, sometime unexpected applications, the review approaches the theme in three separated parts. Part 1 deals with the synthetic method used to prepare the pristine Mg-Al and Zn-Al HTlc and with the procedures of their functionalization with anti-inflammatory (diclofenac), antibacterial (chloramphenicol hemisuccinate), antifibrinolytic (tranexamic acid) drugs and with benzoates with antimicrobial activity. Procedures used to form (nano) composites of polycaprolactone, used as an example of biodegradable polymer, and functionalized HTlc are also reported. Part 2 discusses a patent and related papers on the preparation and biomedical use of a controlled delivery system of the above mentioned pharmacologically active substances. After an introduction dealing with the recent progress in the field of local drug delivery systems, the chemical and structural aspects of the patented system constituted of a biodegradable polymer and HTlc loaded with the active substances will be presented together with an extensive discussion of the drug release in physiological medium. Part 3 deals with a recent patent and related papers on chemical, structural and release property of antimicrobial species of polymeric films containing antimicrobial loaded HTlc able to act as active packaging for food products prolonging their shelf life.

Development of biodegradable metaloxide/polymer nanocomposite films based on poly-ε-caprolactone and terephthalic acid.

Science.gov (United States)

Varaprasad, Kokkarachedu; Pariguana, Manuel; Raghavendra, Gownolla Malegowd; Jayaramudu, Tippabattini; Sadiku, Emmanuel Rotimi

2017-01-01

The present investigation describes the development of metal-oxide polymer nanocomposite films from biodegradable poly-ε-caprolactone, disposed poly(ethylene terephthalate) oil bottles monomer and zinc oxide-copper oxide nanoparticles. The terephthalic acid and zinc oxide-copper oxide nanoparticles were synthesized by using a temperature-dependent precipitation technique and double precipitation method, respectively. The terephthalic acid synthesized was confirmed by FTIR analysis and furthermore, it was characterized by thermal analysis. The as-prepared CuO-ZnO nanoparticles structure was confirmed by XRD analysis and its morphology was analyzed by SEM/EDS and TEM. Furthermore, the metal-oxide polymer nanocomposite films have excellent mechanical properties, with tensile strength and modulus better than pure films. The metal-oxide polymer nanocomposite films that were successfully developed show a relatively brighter colour when compared to CuO film. These new metal-oxide polymer nanocomposite films can replace many non-degradable plastics. The new metal-oxide polymer nanocomposite films developed are envisaged to be suitable for use in industrial and domestic packaging applications. Copyright © 2016 Elsevier B.V. All rights reserved.

Controlled synthesis of biodegradable lactide polymers and copolymers using novel in situ generated or single-site stereoselective polymerisation initiators

NARCIS (Netherlands)

Zhong, Zhiyuan; Dijkstra, Pieter J.; Feijen, Jan

2004-01-01

Polylactides and their copolymers are key biodegradable polymers used widely in biomedical, pharmaceutical and ecological applications. The development of synthetic pathways and catalyst/initiator systems to produce pre-designed polylactides, as well as the fundamental understanding of the

Biodegradable packaging materials conception based on starch and polylactic acid (PLA) reinforced with cellulose.

Science.gov (United States)

Masmoudi, Fatma; Bessadok, Atef; Dammak, Mohamed; Jaziri, Mohamed; Ammar, Emna

2016-10-01

The plastic materials used for packaging are increasing leading to a considerable amount of undegradable solid wastes. This work deals with the reduction of conventional plastics waste and the natural resources preservation by using cellulosic polymers from renewable resources (alfa and luffa). Plasticized starch films syntheses were achieved at a laboratory scale. These natural films showed some very attractive mechanical properties at relatively low plasticizers levels (12 to 17 % by weight). Furthermore, mixtures including polylactic acid polymer (PLA) and cellulose fibers extracted from alfa and luffa were investigated by melt extrusion technique. When used at a rate of 10 %, these fibers improved the mixture mechanical properties. Both developed materials were biodegradable, but the plasticized starch exhibited a faster biodegradation kinetic compared to the PLA/cellulose fibers. These new materials would contribute to a sustainable development and a waste reduction.

Synthesis of biodegradable plastic from tapioca with N-Isopropylacrylamid and chitosan using glycerol as plasticizer

Science.gov (United States)

Syaubari; Safwani, S.; Riza, M.

2018-04-01

One of natural polymers that can be used as raw material in the manufacture of biodegradable plastic is tapioca and chitosan. The addition of other compounds such as glycerol as plasticizer is to improve the characteristics of the plastic that already produced. N- Isopropylacrylamid (NIPAm) is an organic compound that can be synthesized into a polymer or polymer grafting which also biodegradable too. This research aims tostudy the synthesis of biodegradable plastics from tapioca with the addition of chitosan, NIPAm, poly(NIPAm) and analyze the characteristics of biodegradable plastics that already produced. This research was done in three stages, there are (1) polymerization NIPAm, (2) the grafting of chitosan-poly NIPAm and (3) the synthesis of biodegradable plastics from starch mixture with variation of addition chitosan, NIPAm, poly(NIPAm), chitosan-graft-poly(NIPAm) and also variations of glycerol as plasticizer. The results of this research is a thin sheet of plastic which is will get analyzed for the characteristics of functional groups, mechanical, morphological and its biodegradability. FTIR spectra showed the grafting process with the new group formation of CO single-bond at 850 cm-1. Plastic with the addition of NIPAm and 1 ml glycerol has the highest tensile strength value about 31.1 MPa. Plastic with poly(NIPAm) and 4 ml glycerol produces the highest elongation value about 153.72%. Plastic with Chitosan-graft-poly(NIPAm) with 1 ml glycerol has the longest biodegradation because of the small mass-loss for six weeks which is about 6.6%.

Biodegradation of plastics: current scenario and future prospects for environmental safety.

Science.gov (United States)

Ahmed, Temoor; Shahid, Muhammad; Azeem, Farrukh; Rasul, Ijaz; Shah, Asad Ali; Noman, Muhammad; Hameed, Amir; Manzoor, Natasha; Manzoor, Irfan; Muhammad, Sher

2018-03-01

Plastic is a general term used for a wide range of high molecular weight organic polymers obtained mostly from the various hydrocarbon and petroleum derivatives. There is an ever-increasing trend towards the production and consumption of plastics due to their extensive industrial and domestic applications. However, a wide spectrum of these polymers is non-biodegradable with few exceptions. The extensive use of plastics, lack of waste management, and casual community behavior towards their proper disposal pose a significant threat to the environment. This has raised growing concerns among various stakeholders to devise policies and innovative strategies for plastic waste management, use of biodegradable polymers especially in packaging, and educating people for their proper disposal. Current polymer degradation strategies rely on chemical, thermal, photo, and biological procedures. In the presence of proper waste management strategies coupled with industrially controlled biodegradation facilities, the use of biodegradable plastics for some applications such as packaging or health industry is a promising and attractive option for economic, environmental, and health benefits. This review highlights the classification of plastics with special emphasis on biodegradable plastics and their rational use, the identified mechanisms of plastic biodegradation, the microorganisms involved in biodegradation, and the current insights into the research on biodegradable plastics. The review has also identified the research gaps in plastic biodegradation followed by future research directions.

Biodegradable toughened nanohybrid shape memory polymer for smart biomedical applications.

Science.gov (United States)

Biswas, Arpan; Singh, Akhand Pratap; Rana, Dipak; Aswal, Vinod K; Maiti, Pralay

2018-05-17

A polyurethane nanohybrid has been prepared through the in situ polymerization of an aliphatic diisocyanate, ester polyol and a chain extender in the presence of two-dimensional platelets. Polymerization within the platelet galleries helps to intercalate, generate diverse nanostructure and improve the nano to macro scale self-assembly, which leads to a significant enhancement in the toughness and thermal stability of the nanohybrid in comparison to pure polyurethane. The extensive interactions, the reason for property enhancement, between nanoplatelets and polymer chains are revealed through spectroscopic measurements and thermal studies. The nanohybrid exhibits significant improvement in the shape memory phenomena (91% recovery) at the physiological temperature, which makes it suitable for many biomedical applications. The structural alteration, studied through temperature dependent small angle neutron scattering and X-ray diffraction, along with unique crystallization behavior have extensively revealed the special shape memory behavior of this nanohybrid and facilitated the understanding of the molecular flipping in the presence of nanoplatelets. Cell line studies and subsequent imaging testify that this nanohybrid is a superior biomaterial that is suitable for use in the biomedical arena. In vivo studies on albino rats exhibit the potential of the shape memory effect of the nanohybrid as a self-tightening suture in keyhole surgery by appropriately closing the lips of the wound through the recovery of the programmed shape at physiological temperature with faster healing of the wound and without the formation of any scar. Further, the improved biodegradable nature along with the rapid self-expanding ability of the nanohybrid at 37 °C make it appropriate for many biomedical applications including a self-expanding stent for occlusion recovery due to its tough and flexible nature.

Study of biodegradation of partially hydrolyzed polyacrylamide in an oil reservoir after polymer flooding

International Nuclear Information System (INIS)

Bao, M.; Chen, Q.; Li, Y.; Jiang, G.

2009-01-01

Studies have demonstrated that the amide group of polyacrylamides can provide a nitrogen source for microorganisms. However, the carbon backbone of the polymers cannot be cleaved by microbial activity. This study examined the biodegradability of partially hydrolyzed polyacrylamide (HPAM) in an aerobic environment both before and after bacterial biodegradation. Results of the infrared spectrum study indicated that the amide group of HPAM in the products was converted to a carboxyl group. High performance liquid chromatography analyses did not demonstrate the presence of acrylamide monomers. A scanning electron microscopy (SEM) study showed that the surfaces of HPAM particles had been altered by the biodegradation process. Results of the study indicated that the HPAM carbon backbone was metabolized by the bacteria during the course of its growth. It was hypothesized that the HPAM was initially utilized by the bacteria as a nitrogen source by the hydrolysis of the HPAM amide groups using an amidase enzyme. Oxidation of the carbon backbone chain then occurred by monooxygenase catalysis. It was concluded that the HPAM carbon backbone then served as a source for further bacterial growth and metabolism. 13 refs., 5 figs

Radiation processing of natural polymer

International Nuclear Information System (INIS)

Khairul Zaman; Kamaruddin Hashim; Zulkafli Ghazali; Mohd Hilmi Mahmood; Jamaliah Sharif

2006-01-01

Radiation processing of natural polymer has been the subject of interest of countries in this region in the past 5 ∼ 7 years. Although some of the output of the research have been commercialized in particular for the applications in the agriculture and healthcare sectors, the potential applications of radiation processing of natural polymers in the medical sector are yet to be fully understood and developed. (author)

Polymers for Protein Conjugation

Directory of Open Access Journals (Sweden)

Gianfranco Pasut

2014-01-01

Full Text Available Polyethylene glycol (PEG at the moment is considered the leading polymer for protein conjugation in view of its unique properties, as well as to its low toxicity in humans, qualities which have been confirmed by its extensive use in clinical practice. Other polymers that are safe, biodegradable and custom-designed have, nevertheless, also been investigated as potential candidates for protein conjugation. This review will focus on natural polymers and synthetic linear polymers that have been used for protein delivery and the results associated with their use. Genetic fusion approaches for the preparation of protein-polypeptide conjugates will be also reviewed and compared with the best known chemical conjugation ones.

Co-concentration effect of silane with natural extract on biodegradable polymeric films for food packaging.

Science.gov (United States)

Bashir, Anbreen; Jabeen, Sehrish; Gull, Nafisa; Islam, Atif; Sultan, Misbah; Ghaffar, Abdul; Khan, Shahzad Maqsood; Iqbal, Sadia Sagar; Jamil, Tahir

2018-01-01

Novel biodegradable films were prepared by blending guar gum, chitosan and poly (vinyl alcohol) having mint (ME) and grapefruit peel (GE) extracts and crosslinked with nontoxic tetraethoxysilane (TEOS). The co-concentration effect of TEOS with natural extracts on the films was studied. FTIR analysis confirmed the presence of incorporated components and the developed interactions among the polymer chains. The surface morphology of the films by SEM showed the hydrophilic character due to porous network structure. The films having both ME and GE with maximum amount of crosslinker (100μL), showed maximum swelling (58g/g) and stability while the optical properties showed increased protection against UV light. This film sample showed compact network structure which enhanced the ultimate tensile strength (40.03MPa) and elongation at break (104.8%). ME/GE conferred the antioxidant properties determined by radical scavenging activity and total phenolic contents (TPC) as ME films have greater TPC compared to GE films. The soil burial test exhibited the degradation of films rapidly (6days) confirming their strong microbial activity in soil. The lower water vapour transmission rate and water vapour permeability showed better shelf life; hence, these biodegradable films are environmental friendly and have potential for food and other packaging. Copyright © 2017 Elsevier B.V. All rights reserved.

Reduced loss of NH 3 by coating urea with biodegradable polymers ...

African Journals Online (AJOL)

In agricultural lands, the loss of NH3 from surface-applied urea and micronutrient deficiencies are the two most common problems, which can be solved by using coated urea with micronutrients and biodegradable natural materials. These coatings can improve the nutrient status in the soil and simultaneously reduce ...

Abiotic and Biotic Degradation of Oxo-Biodegradable Plastic Bags by Pleurotus ostreatus

OpenAIRE

da Luz, José Maria Rodrigues; Paes, Sirlaine Albino; Bazzolli, Denise Mara Soares; Tótola, Marcos Rogério; Demuner, Antônio Jacinto; Kasuya, Maria Catarina Megumi

2014-01-01

In this study, we evaluated the growth of Pleurotus ostreatus PLO6 using oxo-biodegradable plastics as a carbon and energy source. Oxo-biodegradable polymers contain pro-oxidants that accelerate their physical and biological degradation. These polymers were developed to decrease the accumulation of plastic waste in landfills. To study the degradation of the plastic polymers, oxo-biodegradable plastic bags were exposed to sunlight for up to 120 days, and fragments of these bags were used as su...

Proceedings of biodegradation

International Nuclear Information System (INIS)

Anon.

1990-01-01

This book contains the proceedings of Biodegradation. Topics include:biodegradation using the tools of biotechnology, basic science aspects of biodegradation, the physiological characteristics of microorganisms, the use of selective techniques that enhance the process of microbial evolution of biodegradative genes in nature, the genetic characteristics of microorganisms allowing them to biodegrade both natural and synthetic toxic chemicals, the molecular techniques that allow selective assembly of genetic segments form a variety of bacterial strains to a single strain, and methods needed to advance biodegradation research as well as the high-priority chemical problems important to the Department of Defense or to the chemical industry

Biodegradable Polydepsipeptides

Directory of Open Access Journals (Sweden)

Jintang Guo

2009-02-01

Full Text Available This paper reviews the synthesis, characterization, biodegradation and usage of bioresorbable polymers based on polydepsipeptides. The ring-opening polymerization of morpholine-2,5-dione derivatives using organic Sn and enzyme lipase is discussed. The dependence of the macroscopic properties of the block copolymers on their structure is also presented. Bioresorbable polymers based on polydepsipeptides could be used as biomaterials in drug controlled release, tissue engineering scaffolding and shape-memory materials.

Synthesis of manganese stearate for high density polyethylene (HDPE) and its biodegradation

Science.gov (United States)

Aras, Neny Rasnyanti M.; Arcana, I. Made

2015-09-01

An oxidant additive is one type of additive used for oxo-biodegradable polymers. This additive was prepared by reaction multivalent transition metals and fatty acids to accelerate the degradation process of polymers by providing a thermal treatment or irradiation with light. This study focused on the synthesis of manganese stearate as an additive for application in High Density Polyethylene (HDPE), and the influence of manganese stearate on the characteristics of HDPE including their biodegradability. Manganese stearate was synthesized by the reaction of stearic acid with sodium hydroxide, and sodium stearate formed was reacted with manganese chloride tetrahydrate to form manganese stearate with a melting point of 100-110 °C. Based on the FTIR spectrum showed absorption peak at wave number around 1560 cm-1 which is an asymmetric vibration of CO functional group that binds to the manganese. The films of oxo-biodegradable polymer were prepared by blending HDPE and manganese stearate additives at various concentrations with using the polymer melting method, followed heating at a temperature of 50°C and 70°C for 10 days. The characterizations of the oxo-biodegradable polymers were carried out by analysis the functional groups (FTIR and ATR),thermal properties (TGA), surface properties (SEM), as well as analysis of the biodegradability (the biodegradation test by using activated sludge, % weight loss). Based on COi indicate that the additive of manganese stearate is active in oxidizing polymer by heating treatment. Results of biodegradation by microorganisms from activated sludge showed that the percentage weight loss of polymers increase with the increasing incubation time and the concentration of manganese stearate in HDPE. Biodegradability of HDPE with the addition of manganese stearate and followed by heating at a higher temperature was better observed. The highest percentage weight loss was obtained at the polymer with concentration of 0.2% manganese stearate

Synthesis of manganese stearate for high density polyethylene (HDPE) and its biodegradation

Energy Technology Data Exchange (ETDEWEB)

Aras, Neny Rasnyanti M., E-mail: neny.rasnyanti@gmail.com; Arcana, I Made, E-mail: arcana@chem.itb.ac.id [Inorganic and Physical Chemistry Research Division, Faculty of Mathematics and Natural Sciences, Institut Teknologi Bandung, Jalan Ganesha 10, Bandung 40132 (Indonesia)

2015-09-30

An oxidant additive is one type of additive used for oxo-biodegradable polymers. This additive was prepared by reaction multivalent transition metals and fatty acids to accelerate the degradation process of polymers by providing a thermal treatment or irradiation with light. This study focused on the synthesis of manganese stearate as an additive for application in High Density Polyethylene (HDPE), and the influence of manganese stearate on the characteristics of HDPE including their biodegradability. Manganese stearate was synthesized by the reaction of stearic acid with sodium hydroxide, and sodium stearate formed was reacted with manganese chloride tetrahydrate to form manganese stearate with a melting point of 100-110 °C. Based on the FTIR spectrum showed absorption peak at wave number around 1560 cm{sup −1} which is an asymmetric vibration of CO functional group that binds to the manganese. The films of oxo-biodegradable polymer were prepared by blending HDPE and manganese stearate additives at various concentrations with using the polymer melting method, followed heating at a temperature of 50°C and 70°C for 10 days. The characterizations of the oxo-biodegradable polymers were carried out by analysis the functional groups (FTIR and ATR),thermal properties (TGA), surface properties (SEM), as well as analysis of the biodegradability (the biodegradation test by using activated sludge, % weight loss). Based on COi indicate that the additive of manganese stearate is active in oxidizing polymer by heating treatment. Results of biodegradation by microorganisms from activated sludge showed that the percentage weight loss of polymers increase with the increasing incubation time and the concentration of manganese stearate in HDPE. Biodegradability of HDPE with the addition of manganese stearate and followed by heating at a higher temperature was better observed. The highest percentage weight loss was obtained at the polymer with concentration of 0.2% manganese

Synthesis of manganese stearate for high density polyethylene (HDPE) and its biodegradation

International Nuclear Information System (INIS)

Aras, Neny Rasnyanti M.; Arcana, I Made

2015-01-01

An oxidant additive is one type of additive used for oxo-biodegradable polymers. This additive was prepared by reaction multivalent transition metals and fatty acids to accelerate the degradation process of polymers by providing a thermal treatment or irradiation with light. This study focused on the synthesis of manganese stearate as an additive for application in High Density Polyethylene (HDPE), and the influence of manganese stearate on the characteristics of HDPE including their biodegradability. Manganese stearate was synthesized by the reaction of stearic acid with sodium hydroxide, and sodium stearate formed was reacted with manganese chloride tetrahydrate to form manganese stearate with a melting point of 100-110 °C. Based on the FTIR spectrum showed absorption peak at wave number around 1560 cm −1 which is an asymmetric vibration of CO functional group that binds to the manganese. The films of oxo-biodegradable polymer were prepared by blending HDPE and manganese stearate additives at various concentrations with using the polymer melting method, followed heating at a temperature of 50°C and 70°C for 10 days. The characterizations of the oxo-biodegradable polymers were carried out by analysis the functional groups (FTIR and ATR),thermal properties (TGA), surface properties (SEM), as well as analysis of the biodegradability (the biodegradation test by using activated sludge, % weight loss). Based on COi indicate that the additive of manganese stearate is active in oxidizing polymer by heating treatment. Results of biodegradation by microorganisms from activated sludge showed that the percentage weight loss of polymers increase with the increasing incubation time and the concentration of manganese stearate in HDPE. Biodegradability of HDPE with the addition of manganese stearate and followed by heating at a higher temperature was better observed. The highest percentage weight loss was obtained at the polymer with concentration of 0.2% manganese

Polymer hydrogels as optimized delivery systems

International Nuclear Information System (INIS)

Batista, Jorge G.S.; Varca, Gustavo H.C.; Ferraz, Caroline C.; Garrido, Gabriela P.; Diniz, Bruna M.; Carvalho, Vinicius S.; Lugao, Ademar B.

2013-01-01

Hydrogels are formed by polymers capable of absorbing large quantities of water. They consist of one or more three-dimensionally structured polymer networks formed by macromolecular chains linked by covalent bonds-crosslinks - and physical interactions. The application of hydrogels, has been widely studied. Biodegradable synthetic or natural polymers such as chitosan, starch and poly-lactic-co-glycolic acid, have properties that allow the development of biodegradable systems for drug and nutraceutics delivery. This study aimed to develop polymeric hydrogels based on polyvinyl alcohol, polyacrylamide and polyvinylpyrrolidone using ionizing radiation in order to develop hydrogels for improved loading and release of compounds. Polymer solutions were solubilized in water and poured into thermoformed packages. After sealing, the material was subjected to γ-irradiation at 25kGy. The samples were assayed by means of mechanical properties, gel fraction and swelling degree. Nanostructure characterization was performed using Flory's equation to determine crosslinking density. The systems developed showed swelling degree and adequate mechanical resistance. The nanostructure evaluation showed different results for each system demonstrating the need of choosing the polymer based on the specific properties of each material. (author)

Polymer hydrogels as optimized delivery systems

Energy Technology Data Exchange (ETDEWEB)

Batista, Jorge G.S.; Varca, Gustavo H.C.; Ferraz, Caroline C.; Garrido, Gabriela P.; Diniz, Bruna M.; Carvalho, Vinicius S.; Lugao, Ademar B., E-mail: jorgegabriel@usp.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

2013-07-01

Hydrogels are formed by polymers capable of absorbing large quantities of water. They consist of one or more three-dimensionally structured polymer networks formed by macromolecular chains linked by covalent bonds-crosslinks - and physical interactions. The application of hydrogels, has been widely studied. Biodegradable synthetic or natural polymers such as chitosan, starch and poly-lactic-co-glycolic acid, have properties that allow the development of biodegradable systems for drug and nutraceutics delivery. This study aimed to develop polymeric hydrogels based on polyvinyl alcohol, polyacrylamide and polyvinylpyrrolidone using ionizing radiation in order to develop hydrogels for improved loading and release of compounds. Polymer solutions were solubilized in water and poured into thermoformed packages. After sealing, the material was subjected to γ-irradiation at 25kGy. The samples were assayed by means of mechanical properties, gel fraction and swelling degree. Nanostructure characterization was performed using Flory's equation to determine crosslinking density. The systems developed showed swelling degree and adequate mechanical resistance. The nanostructure evaluation showed different results for each system demonstrating the need of choosing the polymer based on the specific properties of each material. (author)

Naturapolyceutics: The Science of Utilizing Natural Polymers for Drug Delivery

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Ndidi C. Ngwuluka

2014-05-01

Full Text Available Naturapolyceutics defines the emerging science and technology platform that blends natural polymers and pharmaceutics for the design and development of drug delivery systems. Natural polymers due to their biological properties, sustainability, chemical flexibility, human and eco-friendliness are promising in this field. As drug delivery advances, there will be need for more polymers. Given that polymers utilized in pharmaceuticals require regulatory approval, robust processes are undertaken to facilitate the production of pharmaceutical grade natural polymers. This review provides insight into the processes—extraction, purification, modifications and characterizations—involved in the eventual utilization of natural polymers for drug delivery. The versatility of natural polymers and particularly modified natural polymers in targeted drug delivery, micro-/nano-drug delivery, theranostics, BioMEMs and generally in research and development of highly efficient, safe and quality products is demonstrated. Natural polymers are polymers of today and tomorrow. Therefore, the shift to undertake training, extensive research and subsequent commercialization of more natural polymers—novel and underutilized—for drug delivery is now!

Fabrication of a Delaying Biodegradable Magnesium Alloy-Based Esophageal Stent via Coating Elastic Polymer

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Tianwen Yuan

2016-05-01

Full Text Available Esophageal stent implantation can relieve esophageal stenosis and obstructions in benign esophageal strictures, and magnesium alloy stents are a good candidate because of biodegradation and biological safety. However, biodegradable esophageal stents show a poor corrosion resistance and a quick loss of mechanical support in vivo. In this study, we chose the elastic and biodegradable mixed polymer of Poly(ε-caprolactone (PCL and poly(trimethylene carbonate (PTMC as the coated membrane on magnesium alloy stents for fabricating a fully biodegradable esophageal stent, which showed an ability to delay the degradation time and maintain mechanical performance in the long term. After 48 repeated compressions, the mechanical testing demonstrated that the PCL-PTMC-coated magnesium stents possess good flexibility and elasticity, and could provide enough support against lesion compression when used in vivo. According to the in vitro degradation evaluation, the PCL-PTMC membrane coated on magnesium was a good material combination for biodegradable stents. During the in vivo evaluation, the proliferation of the smooth muscle cells showed no signs of cell toxicity. Histological examination revealed the inflammation scores at four weeks in the magnesium-(PCL-PTMC stent group were similar to those in the control group (p > 0.05. The α-smooth muscle actin layer in the media was thinner in the magnesium-(PCL-PTMC stent group than in the control group (p < 0.05. Both the epithelial and smooth muscle cell layers were significantly thinner in the magnesium-(PCL-PTMC stent group than in the control group. The stent insertion was feasible and provided reliable support for at least four weeks, without causing severe injury or collagen deposition. Thus, this stent provides a new stent for the treatment of benign esophageal stricture and a novel research path in the development of temporary stents in other cases of benign stricture.

Synthesis of a novel biodegradable and electroactive polyphosphazene for biomedical application

International Nuclear Information System (INIS)

Zhang Qingsong; Yan Yuhua; Li Shipu; Feng Tao

2009-01-01

To prepare one electroactive and biodegradable biomaterial for biomedical application, a new synthetic strategy was developed to synthesize a novel electrically conductive biodegradable polyphosphazene polymer containing parent aniline pentamer (PAP) and glycine ethyl ester (GEE) as side chains by a nucleophilic substitution reaction. The electrical conductivity of the polymer is ∼2 x 10 -5 S cm -1 in the semiconducting region upon preliminarily protonic-doped experiment. The degradation and RSC96 Schwann cells experiments in vitro prove that the polymer is biodegradable and beneficial to the cell adhesion and proliferation. The as-synthesized polymer also shows good solubility in common organic solvent and good film-forming properties. This new type of polymer has potential applications as scaffolds for neuronal and cardiovascular tissue engineering or other biomedical devices that require electroactivity.

New trends in radiation processing of polymers

International Nuclear Information System (INIS)

Chmielewski, Andrzej G.

2005-01-01

Nowadays, the modification of polymers covers radiation cross-linking, radiation induced polymerization (graft polymerization and curing) and the degradation of polymers. The success of radiation technology for the processing of synthetic polymers can be attributed to two reasons, namely the easiness of processing in various shapes and sizes and, secondly, most of these polymers undergo cross-linking reaction upon exposure to radiation. years, natural polymers are being looked at again with renewed interest because of their unique characteristics like inherent biocompatibility, biodegradability and easy availability. However the recent progress in the field regards development of new processing methods and technical solutions. No other break trough technologies or products based on synthetic polymers are reported recently. The future progress, both from scientific and practical points of view, concerns nanotechnology and natural polymer processing. Overview of the subject, including the works performed in the Institute of the author is presented in the paper. (author)

Preparation of biodegradable gelatin/PVA porous scaffolds for skin regeneration.

Science.gov (United States)

Mahnama, Hossein; Dadbin, Susan; Frounchi, Masoud; Rajabi, Sareh

2017-08-01

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 cells.

Tubular array, dielectric, conductivity and electrochemical properties of biodegradable gel polymer electrolyte

Energy Technology Data Exchange (ETDEWEB)

Sudhakar, Y.N. [Department of Chemistry, Manipal Institute of Technology, Manipal, Karnataka (India); Selvakumar, M., E-mail: chemselva78@gmail.com [Department of Chemistry, Manipal Institute of Technology, Manipal, Karnataka (India); Bhat, D. Krishna [Department of Chemistry, National Institute of Technology Karnataka, Surathkal, Mangalore (India)

2014-02-15

Highlights: • A new finding of tubular array of 10–20 μm in length and 1–2 μm in thickness of gel polymer electrolyte (GPE) having 2.2 × 10{sup −3} S cm{sup −1} conductivity is reported. • Thermal and electrochemical characterizations of GPEs show good interaction among the polymer, plasticizer and salt. • GPE based supercapacitor demonstrates high capacitance of 186 F g{sup −1}. • Low temperature studies did not influence much on capacitance values obtained from AC impedance studies. • Charge–discharge exhibits high capacity with excellent cyclic stability and energy density. -- Abstract: A supercapacitor based on a biodegradable gel polymer electrolyte (GPE) has been fabricated using guar gum (GG) as the polymer matrix, LiClO{sub 4} as the doping salt and glycerol as the plasticizer. The scanning electron microscopy (SEM) images of the gel polymer showed an unusual tubular array type surface morphology. FTIR, DSC and TGA results of the GPE indicated good interaction between the components used. Highest ionic conductivity and lowest activation energy values were 2.2 × 10{sup −3} S cm{sup −1} and 0.18 eV, respectively. Dielectric studies revealed ionic behavior and good capacitance with varying frequency of the GPE system. The fabricated supercapacitor showed a maximum specific capacitance value of 186 F g{sup −1} using cyclic voltammetry. Variation of temperature from 273 K to 293 K did not significantly influence the capacitance values obtained from AC impedance studies. Galvanostatic charge–discharge study of supercapacitor indicated that the device has good stability, high energy density and power density.

Formation of biodegradated polymers as components of future composite materials on the basis of shape memory alloy of medical appointment

Science.gov (United States)

Nasakina, E. O.; Baikin, A. S.; Sergiyenko, K. V.; Kaplan, M. A.; Konushkin, S. V.; Yakubov, A. D.; Izvin, A. V.; Sudarchikova, M. A.; Sevost’yanov, M. A.; Kolmakov, A. G.

2018-04-01

The processes of formation of polymer polylactide or polyglycylidactide films for the subsequent creation of a layered composite with a biodegradable layer on the basis of a nickel-free shape memory alloy TiNbTaZr are studied. The structure of the samples was determined using an SEM. The correspondence of morphology of surfaces of and the substrate itself is noted. High adhesion of the polymer to the future basis of the developed composite material is supposed. The formed films is homogeneous and amorphous throughout the polymer volume. By varying the volume of solutions, it is possible to obtain films of a given thickness for any type of polymer, its molecular weight, and the solution concentration of the polymer in chloroform. Poly (glycolide-lactide) should be more plastic than polylactide.

Biodegradation of polyurethane derived from castor oil

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José M. Cangemi

2008-09-01

Full Text Available The aim of this research was to study the biodegradation of a polymer derived from castor oil, which is a renewable, natural material that is a practical alternative for the replacement of traditional polyurethane foams. Due to its molecular structure, which contains polyester segments derived from vegetable oil, the polymeric surface is susceptible to microorganism attack. This study tested the biological degrading agent that was in contact with the microorganisms resulting from microbiological grease degrading agents, when foam was inoculated. Solid-media agar-plate tests were conducted for their potential to evaluate the biodegradation of polymeric particles by specific strains of microorganisms during 216 hours. The growth rate was defined. This technique provides a way of distinguishing the degradation abilities of microorganisms from the degradability of materials.

Electrospinning polymer blends for biomimetic scaffolds for ACL tissue engineering

Science.gov (United States)

Garcia, Vanessa Lizeth

The anterior cruciate ligament (ACL) rupture is one of the most common knee injuries. Current ACL reconstructive strategies consist of using an autograft or an allograft to replace the ligament. However, limitations have led researchers to create tissue engineered grafts, known as scaffolds, through electrospinning. Scaffolds made of natural and synthetic polymer blends have the potential to promote cell adhesion while having strong mechanical properties. However, enzymes found in the knee are known to degrade tissues and affect the healing of intra-articular injuries. Results suggest that the natural polymers used in this study modify the thermal properties and tensile strength of the synthetic polymers when blended. Scanning electron microscopy display bead-free and enzyme biodegradability of the fibers. Raman spectroscopy confirms the presence of the natural and synthetic polymers in the scaffolds while, amino acid analysis present the types of amino acids and their concentrations found in the natural polymers.

Gold nanoparticles applications in natural polymer modified for UV protection

International Nuclear Information System (INIS)

Silva, Iris O. da; Ladchumananandasivam, Rasiah; Nascimento, Jose H. O. do; Silva, Francisco C. da; Sa, Christiane S. de A.

2015-01-01

The protein-based polymers such as milk, such as polylactic acid (PLA) and soya can be cited as examples of substrates used in various fields of engineering, mainly due to its character of biodegradability, generating low environmental impact when compared to chemical polymers to petroleum-based, which take years to decompose in nature. Among these, soy fiber has great application potential because it is a manufactured material base of a residue obtained from the existing folder in the soybean seeds after oil extraction, using resins and chemicals for structural modification. In this work, soy mesh was used to develop a material with ultraviolet protection properties, through the use of nanotechnology. Thus, to connect the gold nanoparticles (NPAu), the fabric had a surface charge modified with the use of chitosan, using 20% of the weight of the material, followed by nanomaterials exhaust process. The NPAu were synthesized via chemical synthesis with sodium nitrate as reducing and stabilizing agent. The analysis of the solution samples were evaluated by absorbance spectroscopy and solid materials through diffuse reflectance spectroscopy and XRD X-ray diffraction. The size of NPAu was evaluated in equipment Zetasizer nanoseries / nanoZ, finding nanoparticles with an average size of 34.59 nm, and also underlined plasmon resonance phenomenon, with peaks between 530 nm and red coloration, and good results from the soundness washes, compared to conventional dyeing. It was found that soy polymer treated with NPAu presented an excellent property with ultraviolet protection factor (UPF) of +50, considered excellent, proving its potential application in the biomedical field. (author)

Enhancement of spilled oil biodegradation by nutrients of natural origin

International Nuclear Information System (INIS)

Basseres, A.; Eyraud, P.; Ladousse, A.; Tramier, B.

1993-01-01

Ten years ago, Elf Aquitaine began developing the technologies for the acceleration of hydrocarbon biodegradation. The continuation of this work has involved the study of new additives to complement the oleophilic nutrient, INIPOL EAP 22. In particular, it has been shown in both laboratory and in situ tests that hydrocarbon degradation can be accelerated by animal meals, which are natural products. Preliminary laboratory studies carried out under batch conditions have shown that the use of these products has resulted in considerable growth of the bacteria, coupled with a notable increase in the biological degradation kinetics of the hydrocarbons. These results are comparable with the performance of the nutrient INIPOL EAP 22. In situ experiments undertaken on soils polluted by hydrocarbons have shown that by using animal meals, 50 percent biodegradation was obtained after six weeks and this increased to 80 percent when mechanical aeration was also employed. Under nutrient-free control conditions, 25 percent biodegradation was obtained with no aeration and 35 percent with mechanical aeration. In trials using coastal sandy sediments, the use of these nutrients has resulted in an increase of both the number of hydrocarbon specific bacteria and the hydrocarbon degradation. It can be concluded from these pilot experiments that in the development of bioremediation as an operational tool in the response to accidental oil spills, these nutrients of natural origin represent an interesting advance

Full-scale performance of selected starch-based biodegradable polymers in sludge dewatering and recommendation for applications.

Science.gov (United States)

Zhou, Kuangxin; Stüber, Johan; Schubert, Rabea-Luisa; Kabbe, Christian; Barjenbruch, Matthias

2018-01-01

Agricultural reuse of dewatered sludge is a valid route for sludge valorization for small and mid-size wastewater treatment plants (WWTPs) due to the direct utilization of nutrients. A more stringent of German fertilizer ordinance requires the degradation of 20% of the synthetic additives like polymeric substance within two years, which came into force on 1 January 2017. This study assessed the use of starch-based polymers for full-scale dewatering of municipal sewage sludge. The laboratory-scale and pilot-scale trials paved the way for full-scale trials at three WWTPs in Germany. The general feasibility of applying starch-based 'green' polymers in full-scale centrifugation was demonstrated. Depending on the sludge type and the process used, the substitution potential was up to 70%. Substitution of 20-30% of the polyacrylamide (PAM)-based polymer was shown to achieve similar total solids (TS) of the dewatered sludge. Optimization of operational parameters as well as machinery set up in WWTPs is recommended in order to improve the shear stability force of sludge flocs and to achieve higher substitution potential. This study suggests that starch-based biodegradable polymers have great potential as alternatives to synthetic polymers in sludge dewatering.

Natural attenuation of petroleum hydrocarbons-a study of biodegradation effects in groundwater (Vitanovac, Serbia).

Science.gov (United States)

Marić, Nenad; Matić, Ivan; Papić, Petar; Beškoski, Vladimir P; Ilić, Mila; Gojgić-Cvijović, Gordana; Miletić, Srđan; Nikić, Zoran; Vrvić, Miroslav M

2018-01-20

The role of natural attenuation processes in groundwater contamination by petroleum hydrocarbons is of intense scientific and practical interest. This study provides insight into the biodegradation effects in groundwater at a site contaminated by kerosene (jet fuel) in 1993 (Vitanovac, Serbia). Total petroleum hydrocarbons (TPH), hydrochemical indicators (O 2 , NO 3 - , Mn, Fe, SO 4 2- , HCO 3 - ), δ 13 C of dissolved inorganic carbon (DIC), and other parameters were measured to demonstrate biodegradation effects in groundwater at the contaminated site. Due to different biodegradation mechanisms, the zone of the lowest concentrations of electron acceptors and the zone of the highest concentrations of metabolic products of biodegradation overlap. Based on the analysis of redox-sensitive compounds in groundwater samples, redox processes ranged from strictly anoxic (methanogenesis) to oxic (oxygen reduction) within a short distance. The dependence of groundwater redox conditions on the distance from the source of contamination was observed. δ 13 C values of DIC ranged from - 15.83 to - 2.75‰, and the most positive values correspond to the zone under anaerobic and methanogenic conditions. Overall, results obtained provide clear evidence on the effects of natural attenuation processes-the activity of biodegradation mechanisms in field conditions.

Low Density Polyethylene (LDPE blends based on Poly(3-Hydroxi-Butyrate (PHB and Guar Gum (GG biodegradable polymers

Directory of Open Access Journals (Sweden)

Marisa Cristina Guimarães Rocha

2015-02-01

Full Text Available LDPE blends based on PHB and GG biodegradable polymers were prepared by melt mixing in a twin screw extruder. The mechanical properties of the materials were evaluated. Preliminary information about the biodegradation behavior of the specimens was obtained by visual observation of samples removed from the simulated soil in 90 days. The results indicated that LDPE/PHB blends may be used for designing LDPE based materials with increased susceptibility to degradation, if elongation at break and impact properties are not determinant factors of their performance. LDPE based materials on GG present values of flexural and mechanical strength lower than those of LDPE/PHB blends. LDPE/PHB/GG blends exhibit unsatisfactory properties. Apparently, the effect of addition of GG to LDPE on the biodegradation behavior of LDPE/GG blends was less intense than the effect caused by addition of PHB to the blends. Similar observation has occurred with the partial replacement of GG by PHB in the ternary blends.

Nanoparticles from Renewable Polymers

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Frederik Roman Wurm

2014-07-01

Full Text Available The use of polymers from natural resources can bring many benefits for novel polymeric nanoparticle systems. Such polymers have a variety of beneficial properties such as biodegradability and biocompatibility, they are readily available on large scale and at low cost. As the amount of fossil fuels decrease, their application becomes more interesting even if characterization is in many cases more challenging due to structural complexity, either by broad distribution of their molecular weights polysaccharides, polyesters, lignin or by complex structure (proteins, lignin. This review summarizes different sources and methods for the preparation of biopolymer-based nanoparticle systems for various applications.

Mucoadhesive Polymer Hyaluronan as Biodegradable Cationic/Zwitterionic-Drug Delivery Vehicle

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Francisco Torrens

2015-01-01

Full Text Available Mucoadhesive polymers in pharmaceutical formulations release drugs in mucosal areas. They interact and fix to mucus via molecular interpenetration, etc., which increase drug bioavailability. Polymers physicochemical properties affect formulation mucoadhesion, rheological behaviour and drug absorption. Hyaluronan (HA is selected as a mucoadhesive and biodegradable polymer. Geometric, topological and fractal analyses are carried out with program TOPO. Reference calculations are performed with algorithm GEPOL. Procedure TOPO underestimates molecular volume by 0.7%. Error results 5% in surface area and derived topological indices. Solvent-accessible surface is undercalculated by 3%: from hexamer HA to HA·3Ca and hydrate, the hydrophobic term rises by 42% and decays by 26%, and hydrophilic part drops by 14% and rises by 58% in agreement with the number of H-bonds. Accessibility rises by 9% and decays by 8%. Fractal dimension is underevaluated by 1% and for HA it results 1.566; on going to HA·3Ca and hydrate it rises by 2% and 1%. External-atoms dimension increases by 11%: for HA it results 1.725. When going to HA·3Ca and hydrate, it augments by 4% and 0.3%. On going from HA to HA·3Ca and hydrate, nonburied minus molecular dimension enlarges by 20% and decays by 9%. The hydrate globularity is lower than for water, Ca2+ and averages of O-atoms in HA. Ca2+ rugosity is smaller than for hydrate, averages of O-atoms in HA and water. Ca2+ and water accessibilities are greater than for hydrate. As cations exchange in HA·3Ca requires Ca2+ alteration, rises of drug zwitterionic character and acidic pH increase absorption.

Science and sustainability? Biodegradable polymers from canola and flaxseed oils

Energy Technology Data Exchange (ETDEWEB)

Narins, S.S. [Alberta Univ., Edmonton, AB (Canada). Alberta Bioplastics Network

2002-07-01

Little progress has been made in value-added development to crops. The development of biodegradable plastics was spurred by environmental concerns and the use of renewable resources. There is a worldwide market for such products, which complements the strategy of the petrochemical industry. Greater sustainability achieved by partnering with the value-added agricultural industry. The drivers impacting the future polymer industry are: environmental and health concerns, consumer attitudes, cost of cheap feedstocks, carbon credits, greenhouse gases reduction, and criteria air contaminant reduction. Two niche markets are food packaging and biomedical products. The opportunity exists for the development of poly lactic acid (PLA) using canola as a primary feedstock in Alberta as there is a well established petrochemical industry, a vegetable oil infrastructure, and a desire to match petrochemical with bio-renewable. The benefits are higher value processing and a new source of monomers from renewable biomass. The main objective is the development of bio-polymer industry in Alberta based on canola and flaxseed oils. Food and agricultural materials have a similar structure and identical instrumentation to study structure and functionality. The author displayed pictures of the major instrumentation required to conduct this type of research. The rheological properties of polymers include flow, mechanical strength, and thermal properties. The author, along with colleagues, has developed a unique approach. The team members were identified, as well as an overview of the expertise required to perform this research. The author is about to file three related patents. This process is not energy intensive and does not use solvent. The author is about to move into scale-up phase of the reactions which produce the monomers. tabs., figs.

Biopolymer-based thermoplastic mixture for producing solid biodegradable shaped bodies and its photo degradation stability

Science.gov (United States)

Sulong, Nurulsaidatulsyida; Rus, Anika Zafiah M.

2013-12-01

In recent years, biopolymers with controllable lifetimes have become increasingly important for many applications in the areas of agriculture, biomedical implants and drug release, forestry, wild life conservation and waste management. Natural oils are considered to be the most important class of renewable sources. They can be obtained from naturally occurring plants, such as sunflower, cotton, linseed and palm oil. In Malaysia, palm oil is an inexpensive and commodity material. Biopolymer produced from palm oil (Bio-VOP) is a naturally occurring biodegradable polymer and readily available from agriculture. For packaging use however, Bio-VOP is not thermoplastic and its granular form is unsuitable for most uses in the plastics industry, mainly due to processing difficulties during extrusion or injection moulding. Thus, research workers have developed several methods to blend Bio-VOP appropriately for industrial uses. In particular, injections moulding processes, graft copolymerisation, and preparation of blends with thermoplastic polymers have been studied to produce solid biodegradable shaped bodies. HDPE was chosen as commercial thermoplastic materials and was added with 10% Bio-VOP for the preparation of solid biodegradable shaped bodies named as HD-VOP. The UV light exposure of HD-VOP at 12 minutes upon gives the highest strength of this material that is 17.6 MPa. The morphological structure of HD-VOP shows dwi structure surface fracture which is brittle and ductile properties.

New Biofunctional Loading of Natural Antimicrobial Agent in Biodegradable Polymeric Films for Biomedical Applications

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Bakhtawar Ghafoor

2016-01-01

Full Text Available The study focuses on the development of novel Aloe vera based polymeric composite films and antimicrobial suture coatings. Polyvinyl alcohol (PVA, a synthetic biocompatible and biodegradable polymer, was combined with Aloe vera, a natural herb used for soothing burning effects and cosmetic purposes. The properties of these two materials were combined together to get additional benefits such as wound healing and prevention of surgical site infections. PVA and Aloe vera were mixed in a fixed quantity to produce polymer based films. The films were screened for antibacterial and antifungal activity against bacterial (E. coli, P. aeruginosa and fungal strains (Aspergillus flavus and Aspergillus tubingensis screened. Aloe vera based PVA films showed antimicrobial activity against all the strains; the lowest Aloe vera concentration (5% showed the highest activity against all the strains. In vitro degradation and release profile of these films was also evaluated. The coating for sutures was prepared, in vitro antibacterial tests of these coated sutures were carried out, and later on in vivo studies of these coated sutures were also performed. The results showed that sutures coated with Aloe vera/PVA coating solution have antibacterial effects and thus have the potential to be used in the prevention of surgical site infections and Aloe vera/PVA based films have the potential to be used for wound healing purposes.

Potential of Thermophilic microorganisms for the degradation of synthetic polymers

Energy Technology Data Exchange (ETDEWEB)

Dominguez, A.; Deive, F. J.; Sanroman, M. A.; Longo, M. A.

2009-07-01

Nowadays, synthetic polymers are used in all areas of human activity, mainly due to their high stability against environmental conditions and microbial attack. However, these properties are also a problem from an environmental point of view, and thus it is necessary to find biodegradable synthetic polymers that can be easily removed in nature after disposal, and decomposed into biomass, CO{sub 2} and water. (Author)

Biodegradation of polyester. Polyester no bunkai sei

Energy Technology Data Exchange (ETDEWEB)

Tokiwa, Y. (Agency of Industrial Science and Technology, Tokyo (Japan). Fermentation Research Inst.)

1991-09-10

Penicillium sp. 14-3 and penicillium sp. 26-1 can degrade various kinds of polyester. The results of studies made on hydrolysis of polyester by enzyme, hydrolysis of polyester by various kinds of lipase, and degradation of ester type polyurethane by microbes and lipase are introduced. For the improvement of physical properties of aliphatic polyester, aromatic-aliphatic polyester copolymers (CPE) have been synthesized to study the biodegradability. Copolymer in which a number of polyamide (nylon) are alternately introduced (CPAE) to aliphatic polyester has been developed. The result of studies made on the degradability of a blended body of PCL and natural high polymer, and on the collapsibility by lipase of high polymer materials including aliphatic polyamide are introduced. 26 refs., 5 figs., 1 tab.

Biocompatible, biodegradable polymer-based, lighter than or light as water scaffolds for tissue engineering and methods for preparation and use thereof

Science.gov (United States)

Khan, Mohammed Yusuf (Inventor); Laurencin, Cato T. (Inventor); Lu, Helen H. (Inventor); Botchwey, Edward (Inventor); Pollack, Solomon R. (Inventor); Levine, Elliot (Inventor)

2012-01-01

Scaffolds for tissue engineering prepared from biocompatible, biodegradable polymer-based, lighter than or light as water microcarriers and designed for cell culturing in vitro in a rotating bioreactor are provided. Methods for preparation and use of these scaffolds as tissue engineering devices are also provided.

Application of various water soluble polymers in gas hydrate inhibition

DEFF Research Database (Denmark)

Kamal, Muhammad Shahzad; Hussein, Ibnelwaleed A.; Sultan, Abdullah S.

2016-01-01

. This review presents the various types of water soluble polymers used for hydrate inhibition, including conventional and novel polymeric inhibitors along with their limitations. The review covers the relevant properties of vinyl lactam, amide, dendrimeric, fluorinated, and natural biodegradable polymers....... The factors affecting the performance of these polymers and the structure-property relationships are reviewed. A comprehensive review of the techniques used to evaluate the performance of the polymeric inhibitors is given. This review also addresses recent developments, current and future challenges...

The effect of mechanical loads on the degradation of aliphatic biodegradable polyesters.

Science.gov (United States)

Li, Ying; Chu, Zhaowei; Li, Xiaoming; Ding, Xili; Guo, Meng; Zhao, Haoran; Yao, Jie; Wang, Lizhen; Cai, Qiang; Fan, Yubo

2017-06-01

Aliphatic biodegradable polyesters have been the most widely used synthetic polymers for developing biodegradable devices as alternatives for the currently used permanent medical devices. The performances during biodegradation process play crucial roles for final realization of their functions. Because physiological and biochemical environment in vivo significantly affects biodegradation process, large numbers of studies on effects of mechanical loads on the degradation of aliphatic biodegradable polyesters have been launched during last decades. In this review article, we discussed the mechanism of biodegradation and several different mechanical loads that have been reported to affect the biodegradation process. Other physiological and biochemical factors related to mechanical loads were also discussed. The mechanical load could change the conformational strain energy and morphology to weaken the stability of the polymer. Besides, the load and pattern could accelerate the loss of intrinsic mechanical properties of polymers. This indicated that investigations into effects of mechanical loads on the degradation should be indispensable. More combination condition of mechanical loads and multiple factors should be considered in order to keep the degradation rate controllable and evaluate the degradation process in vivo accurately. Only then can the degradable devise achieve the desired effects and further expand the special applications of aliphatic biodegradable polyesters.

Field demonstration of natural biodegradation of BTEX compounds

International Nuclear Information System (INIS)

Borden, R.C.; Davis, C.W.; LeBrun, L.E. IV

1993-01-01

An extensive field study is being conducted at an underground storage tank (UST) release in Sampson Co., NC to aid in understanding the physical, chemical and biological processes controlling the rate and extent of natural bioremediation. Uncontaminated groundwater at the site contains roughly 5 mg/l dissolved oxygen and 15 mg/l nitrate as N. Although the USTs and some soil were removed, much of the NAPL contaminated soil could not be excavated and remains behind as a continuing source of dissolved BTEX. The NAPL gasoline in the subsurface has been naturally biodegrading for several years. Because of the low ground water velocity and high levels of contamination, bioremediation is not yet complete but the effects of oxygen and nitrates enhanced bioremediation are evident. Toluene, ethylbenzene, m + p-xylene and to a lesser extent o-xylene are rapidly removed in a zone less than 125 ft (40 m) wide immediately downgradient from the NAPL source area. A long narrow plume of dissolved benzene and MTBE persists and is migrating downgradient towards a small creek. Biodegradation of the benzene plume appears to be limited by diffusion of oxygen into the anoxic plume. In aerobic microcosms, all BTEX components were rapidly removed to below detection. Toluene and ethylbenzene were removed to below 10 ug/l in the denitrifying microcosms after an extended lag period

Can natural polymers assist in delivering insulin orally?

Science.gov (United States)

Nur, Mokhamad; Vasiljevic, Todor

2017-10-01

Diabetes mellitus is one of the most grave and lethal non communicable diseases. Insulin is normally used to medicate diabetes. Due to bioavailability issues, the most regular route of administration is through injection, which may pose compliance problems to treatment. The oral administration thus appears as a suitable alternative, but with several important problems. Low stability of insulin in the gastrointestinal tract and low intestinal permeation are some of the issues. Encapsulation of insulin into polymer-based particles emerges as a plausible strategy. Different encapsulation approaches and polymers have been used in this regard. Polymers with different characteristics from natural or synthetic origin have been assessed to attain this goal, with natural polymers being preferable. Natural polymers studied so far include chitosan, alginate, carrageenan, starch, pectin, casein, tragacanth, dextran, carrageenan, gelatine and cyclodextrin. While some promising knowledge and results have been gained, a polymeric-based particle system to deliver insulin orally has not been introduced onto the market yet. In this review, effectiveness of different natural polymer materials developed so far along with fabrication techniques are evaluated. Copyright © 2017 Elsevier B.V. All rights reserved.

Biodegradable magnesium alloys for orthopaedic applications: A review on corrosion, biocompatibility and surface modifications.

Science.gov (United States)

Agarwal, Sankalp; Curtin, James; Duffy, Brendan; Jaiswal, Swarna

2016-11-01

Magnesium (Mg) and its alloys have been extensively explored as potential biodegradable implant materials for orthopaedic applications (e.g. Fracture fixation). However, the rapid corrosion of Mg based alloys in physiological conditions has delayed their introduction for therapeutic applications to date. The present review focuses on corrosion, biocompatibility and surface modifications of biodegradable Mg alloys for orthopaedic applications. Initially, the corrosion behaviour of Mg alloys and the effect of alloying elements on corrosion and biocompatibility is discussed. Furthermore, the influence of polymeric deposit coatings, namely sol-gel, synthetic aliphatic polyesters and natural polymers on corrosion and biological performance of Mg and its alloy for orthopaedic applications are presented. It was found that inclusion of alloying elements such as Al, Mn, Ca, Zn and rare earth elements provides improved corrosion resistance to Mg alloys. It has been also observed that sol-gel and synthetic aliphatic polyesters based coatings exhibit improved corrosion resistance as compared to natural polymers, which has higher biocompatibility due to their biomimetic nature. It is concluded that, surface modification is a promising approach to improve the performance of Mg-based biomaterials for orthopaedic applications. Copyright © 2016 Elsevier B.V. All rights reserved.

Study of nanocomposites prepared from polyamides and biodegradable polyesters and poly(ester amide)s

OpenAIRE

Morales Gámez, Laura Teresa

2012-01-01

Premi extraordinari doctorat curs 2011-2012, àmbit d’Enginyeria Industrial Polymer clay nanocomposites of polyamides and biodegradable polymers with three kinds of organomodified clays were prepared by different techniques (in situ polymerization, solution casting, and melt mixing). The polymers used in this research were nylons 56, 65 and 47 and the biodegradable polymers: poly (glycolic acid-alt-6-hydrohexanoic acid) and poly(glycolic acid-alt-6-aminohexanoic acid). The developmen...

Bio-plastic (P-3HB-co-3HV) from Bacillus circulans (MTCC 8167) and its biodegradation.

Science.gov (United States)

Phukon, Pinkee; Saikia, Jyoti Prasad; Konwar, Bolin Kumar

2012-04-01

Polyhydroxyalkanoates (PHAs) are naturally occurring polyesters synthesized by bacteria for carbon and energy storage and it has commercial potential as bioplastic. The bacterial species Bacillus circulans MTCC 8167, isolated from crude oil contaminated soil, can efficiently produce medium chain length polyhydroxyalkanoates (P-3HB-co-3HV) from cheap carbon sources like dextrose. The molecular mass of P-3HB-co-3HV was reported as 5.1×10(4)Da with polydispersity index of 1.21 by gel permeation chromatography. In the present investigation different bacteria and fungi species were used for testing the biodegradability of the extracted polymer. The FTIR spectra of the biodegraded PHBV film showed a decrease in the peak from 1735 cm(-1) (untreated film) to 1675 cm(-1), and disappearance of a peak present in the control at 2922 cm(-1) indicating the breakdown of ester (>C=O) or O-R group and -C=H bond, respectively. From biodegradability testing, the tested microorganisms were found to have decisive contribution to the biodegradation of P-3HB-co-3HV polymer. Copyright © 2011 Elsevier B.V. All rights reserved.

Silica in situ enhanced PVA/chitosan biodegradable films for food packages.

Science.gov (United States)

Yu, Zhen; Li, Baoqiang; Chu, Jiayu; Zhang, Peifeng

2018-03-15

Non-degradable plastic food packages threaten the security of environment. The cost-effective and biodegradable polymer films with good mechanical properties and low permeability are very important for food packages. Among of biodegradable polymers, PVA/chitosan (CS) biodegradable films have attracted considerable attention because of feasible film forming ability. However, PVA/CS biodegradable films suffered from poor mechanical properties. To improve mechanical properties of PVA/CS biodegradable films, we developed SiO 2 in situ to enhance PVA/CS biodegradable films via hydrolysis of sodium metasilicate in presence of PVA and chitosan solution. The tensile strength of PVA/CS biodegradable films was improved 45% when 0.6 wt.% SiO 2 was incorporated into the films. Weight loss of PVA/CS biodegradable films was 60% after 30 days in the soil. The permeability of oxygen and moisture of PVA/CS biodegradable films was reduced by 25.6% and 10.2%, respectively. SiO 2 in situ enhanced PVA/CS biodegradable films possessed not only excellent mechanical properties, but also barrier of oxygen and water for food packages to extend the perseveration time. Copyright © 2017 Elsevier Ltd. All rights reserved.

Core–shell composite particles composed of biodegradable polymer particles and magnetic iron oxide nanoparticles for targeted drug delivery

Energy Technology Data Exchange (ETDEWEB)

Oka, Chiemi; Ushimaru, Kazunori [Department of Innovative and Engineered Materials, Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama 226-8502 (Japan); Horiishi, Nanao [Bengala Techno Laboratory, 9-5-1006, 1-1 Kodai, Miyamae-ku, Kawasaki 216-0007 (Japan); Tsuge, Takeharu [Department of Innovative and Engineered Materials, Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama 226-8502 (Japan); Kitamoto, Yoshitaka, E-mail: kitamoto.y.aa@m.titech.ac.jp [Department of Innovative and Engineered Materials, Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama 226-8502 (Japan)

2015-05-01

Core–shell composite particles with biodegradability and superparamagnetic behavior were prepared using a Pickering emulsion for targeted drug delivery based on magnetic guidance. The composite particles were composed of a core of biodegradable polymer and a shell of assembled magnetic iron oxide nanoparticles. It was found that the dispersibility of the nanoparticles is crucial for controlling the core–shell structure. The addition of a small amount of dispersant into the nanoparticle's suspension could improve the dispersibility and led to the formation of composite particles with a thin magnetic shell covering a polymeric core. The composite particles were also fabricated with a model drug loaded into the core, which was released via hydrolysis of the core under strong alkaline conditions. Because the core can also be biodegraded by lipase, this result suggests that the slow release of the drug from the composite particles should occur inside the body. - Highlights: • Core−shell composites with biodegradability and magnetism are prepared. • O/W emulsion stabilized by iron oxide nanoparticles is utilized for the preparation. • The nanoparticle's dispersibility is crucial for controlling the composite structure. • Composites loading a model drug are also prepared. • The model drug is released with decomposition of the composites.

Biodegradability of polyurethane/polysaccharide blends

International Nuclear Information System (INIS)

Mothe, Cheila G.; Leite, Selma G.

2001-01-01

Biodegradable polymers for use in environmental waste-management has been the subject of much discussion over the last few years. Polyurethane mixtures with polysaccharide (80/20 and 90/10 w/w ) have been prepared and films obtained. These films were inoculated, according to ASTM G22-76 rule and analysed by thermogravimetry and scanning electronic microscopy (SEM). The results are discussed in terms of thermal degradation and biodegradability. (author)

Effect of Babassu Natural Filler on PBAT/PHB Biodegradable Blends: An Investigation of Thermal, Mechanical, and Morphological Behavior

Directory of Open Access Journals (Sweden)

Vinicius C. Beber

2018-05-01

Full Text Available Blending of biodegradable polymers in combination with low-price organic fillers has proven to be a suitable approach to produce cost-effective composites in order to address pollution issues and develop products with superior mechanical properties. In the present research work PBAT/PHB/Babassu composites with 25, 50, and 75% of each polymer and 20% of Babassu were produced by melting extrusion. Their thermal, mechanical, and morphological behavior was investigated by differential scanning calorimetry (DSC, tensile testing, and scanning electron microscopy (SEM. Blending PBAT with PHB inhibited the crystallization of both polymers whereas adding Babassu did not significantly change their melting behaviour. Incorporation of Babassu reduced the tensile strength of its respective blends between 4.8 and 32.3%, and elongation at break between 26.0 and 66.3%. PBAT as highly ductile and low crystalline polymer may be seen as a crystallization tool control for PHB as well as a plasticizer to PBAT/PHB blends and PBAT/PHB/Babassu composites. As PBAT content increases: (i elongation at break increases and (ii surface fracture becomes more refined indicating the presence of more energy dissipation mechanisms. As PBAT/PHB/Babassu composites are biodegradable, environmental friendly, and cost effective, products based on these compounds have a great potential since their mechanical properties such as ductility, stiffness, and tensile strength are still suitable for several applications even at lower temperatures (−40 °C.

Biodegradable polymeric nanocarriers for pulmonary drug delivery.

Science.gov (United States)

Rytting, Erik; Nguyen, Juliane; Wang, Xiaoying; Kissel, Thomas

2008-06-01

Pulmonary drug delivery is attractive for both local and systemic drug delivery as a non-invasive route that provides a large surface area, thin epithelial barrier, high blood flow and the avoidance of first-pass metabolism. Nanoparticles can be designed to have several advantages for controlled and targeted drug delivery, including controlled deposition, sustained release, reduced dosing frequency, as well as an appropriate size for avoiding alveolar macrophage clearance or promoting transepithelial transport. This review focuses on the development and application of biodegradable polymers to nanocarrier-based strategies for the delivery of drugs, peptides, proteins, genes, siRNA and vaccines by the pulmonary route. The selection of natural or synthetic materials is important in designing particles or nanoparticle clusters with the desired characteristics, such as biocompatibility, size, charge, drug release and polymer degradation rate.

Simple and cost-effective fabrication of solid biodegradable polymer microneedle arrays with adjustable aspect ratio for transdermal drug delivery using acupuncture microneedles

Science.gov (United States)

Cha, Kyoung Je; Kim, Taewan; Jea Park, Sung; Kim, Dong Sung

2014-11-01

Polymer microneedle arrays (MNAs) have received much attention for their use in transdermal drug delivery and microneedle therapy systems due to the advantages they offer, such as low cost, good mechanical properties, and a versatile choice of materials. Here, we present a simple and cost-effective method for the fabrication of a biodegradable polymer MNA in which the aspect ratio of each microneedle is adjustable using commercially available acupuncture microneedles. In our process, a master template with acupuncture microneedles, whose shape will be the final MNA, was carefully prepared by fixing them onto a plastic substrate with selectively drilled holes which, in turn, determine the aspect ratios of the microneedles. A polylactic acid (PLA; a biodegradable polymer) MNA was fabricated by a micromolding process with a polydimethylsiloxane (PDMS) mold containing the cavity of the microneedles, which was obtained by the PDMS replica molding against the master template. The mechanical force and degradation behavior of the replicated PLA MNA were characterized with the help of a compression test and an accelerated degradation test, respectively. Finally, the transdermal drug delivery performance of the PLA MNA was successfully simulated by two different methods of penetration and staining, using the skin of a pig cadaver. These results indicated that the proposed method can be effectively used for the fabrication of polymer MNAs which can be used in various microneedle applications.

Simple and cost-effective fabrication of solid biodegradable polymer microneedle arrays with adjustable aspect ratio for transdermal drug delivery using acupuncture microneedles

International Nuclear Information System (INIS)

Cha, Kyoung Je; Kim, Taewan; Park, Sung Jea; Kim, Dong Sung

2014-01-01

Polymer microneedle arrays (MNAs) have received much attention for their use in transdermal drug delivery and microneedle therapy systems due to the advantages they offer, such as low cost, good mechanical properties, and a versatile choice of materials. Here, we present a simple and cost-effective method for the fabrication of a biodegradable polymer MNA in which the aspect ratio of each microneedle is adjustable using commercially available acupuncture microneedles. In our process, a master template with acupuncture microneedles, whose shape will be the final MNA, was carefully prepared by fixing them onto a plastic substrate with selectively drilled holes which, in turn, determine the aspect ratios of the microneedles. A polylactic acid (PLA; a biodegradable polymer) MNA was fabricated by a micromolding process with a polydimethylsiloxane (PDMS) mold containing the cavity of the microneedles, which was obtained by the PDMS replica molding against the master template. The mechanical force and degradation behavior of the replicated PLA MNA were characterized with the help of a compression test and an accelerated degradation test, respectively. Finally, the transdermal drug delivery performance of the PLA MNA was successfully simulated by two different methods of penetration and staining, using the skin of a pig cadaver. These results indicated that the proposed method can be effectively used for the fabrication of polymer MNAs which can be used in various microneedle applications. (paper)

Modification of Edible Food Packaging Materials Based on Natural Polymer Blends by Ionizing Radiation

International Nuclear Information System (INIS)

ALI, H.El-Sh.

2010-01-01

Blends based on different ratios of plasticised starch (PLST), poly (vinyl alcohol) (PVA) and carboxymethyl cellulose (CMC) were prepared by solution casting in the form of thin films. The PLST/PVA and PLST/CMC films were exposed to different doses of gamma radiation. The effect of gamma-irradiation on the thermal, mechanical and structure morphology properties was investigated. As an application in the field of the prolongation of food preservation life time, Mango fruits were coated with solutions of gamma-irradiated PLST/PVA and PLST/CMC blends in the presence of chitosan, as an antimicrobial material, to form thin films. The results showed that the gamma-irradiation improved all the physical properties, which provides suitable materials based on natural biodegradable polymers for food preservation withstanding the temperature and stresses.

A Wireless Pressure Sensor Integrated with a Biodegradable Polymer Stent for Biomedical Applications.

Science.gov (United States)

Park, Jongsung; Kim, Ji-Kwan; Patil, Swati J; Park, Jun-Kyu; Park, SuA; Lee, Dong-Weon

2016-06-02

This paper describes the fabrication and characterization of a wireless pressure sensor for smart stent applications. The micromachined pressure sensor has an area of 3.13 × 3.16 mm² and is fabricated with a photosensitive SU-8 polymer. The wireless pressure sensor comprises a resonant circuit and can be used without the use of an internal power source. The capacitance variations caused by changes in the intravascular pressure shift the resonance frequency of the sensor. This change can be detected using an external antenna, thus enabling the measurement of the pressure changes inside a tube with a simple external circuit. The wireless pressure sensor is capable of measuring pressure from 0 mmHg to 230 mmHg, with a sensitivity of 0.043 MHz/mmHg. The biocompatibility of the pressure sensor was evaluated using cardiac cells isolated from neonatal rat ventricular myocytes. After inserting a metal stent integrated with the pressure sensor into a cardiovascular vessel of an animal, medical systems such as X-ray were employed to consistently monitor the condition of the blood vessel. No abnormality was found in the animal blood vessel for approximately one month. Furthermore, a biodegradable polymer (polycaprolactone) stent was fabricated with a 3D printer. The polymer stent exhibits better sensitivity degradation of the pressure sensor compared to the metal stent.

A Wireless Pressure Sensor Integrated with a Biodegradable Polymer Stent for Biomedical Applications

Directory of Open Access Journals (Sweden)

Jongsung Park

2016-06-01

Full Text Available This paper describes the fabrication and characterization of a wireless pressure sensor for smart stent applications. The micromachined pressure sensor has an area of 3.13 × 3.16 mm2 and is fabricated with a photosensitive SU-8 polymer. The wireless pressure sensor comprises a resonant circuit and can be used without the use of an internal power source. The capacitance variations caused by changes in the intravascular pressure shift the resonance frequency of the sensor. This change can be detected using an external antenna, thus enabling the measurement of the pressure changes inside a tube with a simple external circuit. The wireless pressure sensor is capable of measuring pressure from 0 mmHg to 230 mmHg, with a sensitivity of 0.043 MHz/mmHg. The biocompatibility of the pressure sensor was evaluated using cardiac cells isolated from neonatal rat ventricular myocytes. After inserting a metal stent integrated with the pressure sensor into a cardiovascular vessel of an animal, medical systems such as X-ray were employed to consistently monitor the condition of the blood vessel. No abnormality was found in the animal blood vessel for approximately one month. Furthermore, a biodegradable polymer (polycaprolactone stent was fabricated with a 3D printer. The polymer stent exhibits better sensitivity degradation of the pressure sensor compared to the metal stent.

Biodegradable multiblock polymers based on N-(2-hydroxypropyl)methacrylamide designed as drug carriers for tumor-targeted delivery

Czech Academy of Sciences Publication Activity Database

Mužíková, Gabriela; Pola, Robert; Laga, Richard; Pechar, Michal

2016-01-01

Roč. 217, č. 15 (2016), s. 1690-1703 ISSN 1022-1352 R&D Projects: GA ČR(CZ) GA14-12742S; GA ČR(CZ) GA16-17207S; GA MŠk(CZ) LO1507; GA MŠk(CZ) LQ1604; GA MŠk(CZ) ED1.1.00/02.0109 Institutional support: RVO:61389013 Keywords : biodegradable polymers * click chemistry * drug delivery systems Subject RIV: CD - Macromolecular Chemistry Impact factor: 2.500, year: 2016

Polymer Film-Based Screening and Isolation of Polylactic Acid (PLA)-Degrading Microorganisms.

Science.gov (United States)

Kim, Mi Yeon; Kim, Changman; Moon, Jungheun; Heo, Jinhee; Jung, Sokhee P; Kim, Jung Rae

2017-02-28

Polylactic acid (PLA) has been highlighted as an alternative renewable polymer for the replacement of petroleum-based plastic materials, and is considered to be biodegradable. On the other hand, the biodegradation of PLA by terminal degraders, such as microorganisms, requires a lengthy period in the natural environment, and its mechanism is not completely understood. PLA biodegradation studies have been conducted using mainly undefined mixed cultures, but only a few bacterial strains have been isolated and examined. For further characterization of PLA biodegradation, in this study, the PLA-degrading bacteria from digester sludge were isolated and identified using a polymer film-based screening method. The enrichment of sludge on PLA granules was conducted with the serial transference of a subculture into fresh media for 40 days, and the attached biofilm was inoculated on a PLA film on an agar plate. 3D optical microscopy showed that the isolates physically degraded the PLA film due to bacterial degradation. 16S rRNA gene sequencing identified the microbial colonies to be Pseudomonas sp. MYK1 and Bacillus sp. MYK2. The two isolates exhibited significantly higher specific gas production rates from PLA biodegradation compared with that of the initial sludge inoculum.

Degradation of oxo-biodegradable plastic by Pleurotus ostreatus.

Science.gov (United States)

da Luz, José Maria Rodrigues; Paes, Sirlaine Albino; Nunes, Mateus Dias; da Silva, Marliane de Cássia Soares; Kasuya, Maria Catarina Megumi

2013-01-01

Growing concerns regarding the impact of the accumulation of plastic waste over several decades on the environmental have led to the development of biodegradable plastic. These plastics can be degraded by microorganisms and absorbed by the environment and are therefore gaining public support as a possible alternative to petroleum-derived plastics. Among the developed biodegradable plastics, oxo-biodegradable polymers have been used to produce plastic bags. Exposure of this waste plastic to ultraviolet light (UV) or heat can lead to breakage of the polymer chains in the plastic, and the resulting compounds are easily degraded by microorganisms. However, few studies have characterized the microbial degradation of oxo-biodegradable plastics. In this study, we tested the capability of Pleurotus ostreatus to degrade oxo-biodegradable (D2W) plastic without prior physical treatment, such as exposure to UV or thermal heating. After 45 d of incubation in substrate-containing plastic bags, the oxo-biodegradable plastic, which is commonly used in supermarkets, developed cracks and small holes in the plastic surface as a result of the formation of hydroxyl groups and carbon-oxygen bonds. These alterations may be due to laccase activity. Furthermore, we observed the degradation of the dye found in these bags as well as mushroom formation. Thus, P. ostreatus degrades oxo-biodegradable plastics and produces mushrooms using this plastic as substrate.

Degradation of oxo-biodegradable plastic by Pleurotus ostreatus.

Directory of Open Access Journals (Sweden)

José Maria Rodrigues da Luz

Full Text Available Growing concerns regarding the impact of the accumulation of plastic waste over several decades on the environmental have led to the development of biodegradable plastic. These plastics can be degraded by microorganisms and absorbed by the environment and are therefore gaining public support as a possible alternative to petroleum-derived plastics. Among the developed biodegradable plastics, oxo-biodegradable polymers have been used to produce plastic bags. Exposure of this waste plastic to ultraviolet light (UV or heat can lead to breakage of the polymer chains in the plastic, and the resulting compounds are easily degraded by microorganisms. However, few studies have characterized the microbial degradation of oxo-biodegradable plastics. In this study, we tested the capability of Pleurotus ostreatus to degrade oxo-biodegradable (D2W plastic without prior physical treatment, such as exposure to UV or thermal heating. After 45 d of incubation in substrate-containing plastic bags, the oxo-biodegradable plastic, which is commonly used in supermarkets, developed cracks and small holes in the plastic surface as a result of the formation of hydroxyl groups and carbon-oxygen bonds. These alterations may be due to laccase activity. Furthermore, we observed the degradation of the dye found in these bags as well as mushroom formation. Thus, P. ostreatus degrades oxo-biodegradable plastics and produces mushrooms using this plastic as substrate.

Degradation of Oxo-Biodegradable Plastic by Pleurotus ostreatus

Science.gov (United States)

da Luz, José Maria Rodrigues; Paes, Sirlaine Albino; Nunes, Mateus Dias; da Silva, Marliane de Cássia Soares; Kasuya, Maria Catarina Megumi

2013-01-01

Growing concerns regarding the impact of the accumulation of plastic waste over several decades on the environmental have led to the development of biodegradable plastic. These plastics can be degraded by microorganisms and absorbed by the environment and are therefore gaining public support as a possible alternative to petroleum-derived plastics. Among the developed biodegradable plastics, oxo-biodegradable polymers have been used to produce plastic bags. Exposure of this waste plastic to ultraviolet light (UV) or heat can lead to breakage of the polymer chains in the plastic, and the resulting compounds are easily degraded by microorganisms. However, few studies have characterized the microbial degradation of oxo-biodegradable plastics. In this study, we tested the capability of Pleurotus ostreatus to degrade oxo-biodegradable (D2W) plastic without prior physical treatment, such as exposure to UV or thermal heating. After 45 d of incubation in substrate-containing plastic bags, the oxo-biodegradable plastic, which is commonly used in supermarkets, developed cracks and small holes in the plastic surface as a result of the formation of hydroxyl groups and carbon-oxygen bonds. These alterations may be due to laccase activity. Furthermore, we observed the degradation of the dye found in these bags as well as mushroom formation. Thus, P. ostreatus degrades oxo-biodegradable plastics and produces mushrooms using this plastic as substrate. PMID:23967057

Influence of gamma radiation in the mechanical properties of partially biodegradable foams of PP/HMSP blends with sugar cane bagasse

International Nuclear Information System (INIS)

Cardoso, Elizabeth C.L.; Scagliusi, Sandra R.; Mascarenha, Yago; Lugao, Ademar B.

2015-01-01

Polymers are used in various applications and in different market segments generating enormous amounts of wastes in environment. Among residues components in landfills are polymeric materials, as PP, contributing with 20 to 30% of total solids residues. As polymeric materials are immune to microbial degradation, remain in soil and in landfills as a semi-permanent residue. Environmental concerning toward residues reduction is nowadays directed to the development of renewable polymers for manufacturing of materials that degrade under environment, as biodegradable polymeric foams. High density structural foams are especially used in civil construction, replacing metals, woods and concrete, with a major purpose of materials cost reduction. This work aims to the study of biodegradability in PP/HMSPP blends with sugarcane bagasse at 10, 15, 30 and 50% further irradiated at 50, 100, 150 and 200 kGy doses. The biodegradability was assessed via Soil Burial Test. Tensile strength and elongation at break results proved that natural fibers reinforcement characteristic was not affected by gamma radiation, responsible by degradation and consequent biodegradability acceleration in structural foams. (author)

A constitutive law for degrading bioresorbable polymers.

Science.gov (United States)

Samami, Hassan; Pan, Jingzhe

2016-06-01

This paper presents a constitutive law that predicts the changes in elastic moduli, Poisson's ratio and ultimate tensile strength of bioresorbable polymers due to biodegradation. During biodegradation, long polymer chains are cleaved by hydrolysis reaction. For semi-crystalline polymers, the chain scissions also lead to crystallisation. Treating each scission as a cavity and each new crystal as a solid inclusion, a degrading semi-crystalline polymer can be modelled as a continuum solid containing randomly distributed cavities and crystal inclusions. The effective elastic properties of a degrading polymer are calculated using existing theories for such solid and the tensile strength of the degrading polymer is predicted using scaling relations that were developed for porous materials. The theoretical model for elastic properties and the scaling law for strength form a complete constitutive relation for the degrading polymers. It is shown that the constitutive law can capture the trend of the experimental data in the literature for a range of biodegradable polymers fairly well. Copyright © 2016 Elsevier Ltd. All rights reserved.

Recent Advances in Edible Polymer Based Hydrogels as a Sustainable Alternative to Conventional Polymers.

Science.gov (United States)

Ali, Akbar; Ahmed, Shakeel

2018-06-26

The over increasing demand of eco-friendly materials to counter various problems, such as environmental issues, economics, sustainability, biodegradability, and biocompatibility, open up new fields of research highly focusing on nature-based products. Edible polymer based materials mainly consisting of polysaccharides, proteins, and lipids could be a prospective contender to handle such problems. Hydrogels based on edible polymer offer many valuable properties compared to their synthetic counterparts. Edible polymers can contribute to the reduction of environmental contamination, advance recyclability, provide sustainability, and thereby increase its applicability along with providing environmentally benign products. This review is highly emphasizing on toward the development of hydrogels from edible polymer, their classification, properties, chemical modification, and their potential applications. The application of edible polymer hydrogels covers many areas including the food industry, agricultural applications, drug delivery to tissue engineering in the biomedical field and provide more safe and attractive products in the pharmaceutical, agricultural, and environmental fields, etc.

Applicability and limits of Sturm modified method for evaluation of polymer biodegradability. Applicabilita' e limiti del metodo di Sturm modificato per valutare biodegradabilita' di polimeri plastici

Energy Technology Data Exchange (ETDEWEB)

Musmeci, L.; Volterra, L.; Gucci, P.M.B.; Semproni, M.; Coccia, A.M. (Istituto Superiore di Sanita, Rome (Italy))

1993-01-01

The admission of 'biodegradable' plastics on the market has determined the development of analytical methods for measuring and controlling their biodegradation. The Modified Sturm Test was selected as a method. This paper presents the results of two experiments in which different and acclimatized/acclimatization microorganisms were used as inocula. The pre-acclimatization was performed on polyethylene alone or with starch additions, respectively. Starch addition in the acclimatization phase induces the selection of a population able to speed up the starch mineralization but not equally able to further biodegrade plastic polymers.

A Literature Review on the Study of Moisture in Polymers

Energy Technology Data Exchange (ETDEWEB)

Trautschold, Olivia Carol [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

2016-05-25

This literature review covers the main chemical and physical interactions between moisture and the polymer matrix. Fickian versus Non-Fickian diffusion behaviors are discussed in approximating the characteristics of moisture sorption. Also, bound water and free water sorbed in polymers are distinguished. Methods to distinguish between bound and free water include differential scanning calorimetry, infrared spectroscopy, and time-domain nuclear magnetic resonance spectroscopy. The difference between moisture sorption and water sorption is considered, as well as the difficulties associated with preventing moisture sorption. Furthermore, specific examples of how moisture sorption influences polymers include natural fiber-polymer composites, starch-based biodegradable thermoplastics, and thermoset polyurethane and epoxies.

A Review on Recent Advances in Stabilizing Peptides/Proteins upon Fabrication in Hydrogels from Biodegradable Polymers.

Science.gov (United States)

Raza, Faisal; Zafar, Hajra; Zhu, Ying; Ren, Yuan; -Ullah, Aftab; Khan, Asif Ullah; He, Xinyi; Han, Han; Aquib, Md; Boakye-Yiadom, Kofi Oti; Ge, Liang

2018-01-18

Hydrogels evolved as an outstanding carrier material for local and controlled drug delivery that tend to overcome the shortcomings of old conventional dosage forms for small drugs (NSAIDS) and large peptides and proteins. The aqueous swellable and crosslinked polymeric network structure of hydrogels is composed of various natural, synthetic and semisynthetic biodegradable polymers. Hydrogels have remarkable properties of functionality, reversibility, sterilizability, and biocompatibility. All these dynamic properties of hydrogels have increased the interest in their use as a carrier for peptides and proteins to be released slowly in a sustained manner. Peptide and proteins are remarkable therapeutic agents in today's world that allow the treatment of severe, chronic and life-threatening diseases, such as diabetes, rheumatoid arthritis, hepatitis. Despite few limitations, hydrogels provide fine tuning of proteins and peptides delivery with enormous impact in clinical medicine. Novels drug delivery systems composed of smart peptides and molecules have the ability to drive self-assembly and form hydrogels at physiological pH. These hydrogels are significantly important for biological and medical fields. The primary objective of this article is to review current issues concerned with the therapeutic peptides and proteins and impact of remarkable properties of hydrogels on these therapeutic agents. Different routes for pharmaceutical peptides and proteins and superiority over other drugs candidates are presented. Recent advances based on various approaches like self-assembly of peptides and small molecules to form novel hydrogels are also discussed. The article will also review the literature concerning the classification of hydrogels on a different basis, polymers used, "release mechanisms" their physical and chemical characteristics and diverse applications.

CLASSIFICATION OF BIODEGRADABLE POLYMERS

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I. I. Karpunin

2015-01-01

Full Text Available The executed investigations have made it possible to ascertain that a morphological structure of starch granules mainly determine technological peculiarities of starch isolation from raw material, its modification and its later use. Morphological structure of starch granules primarily depends on type of plant starch-containing raw material which has been used for its isolation. Class of raw material exerts a strong impact on the shape and size of the granules. Linear “light” amylose chains and “heavy” amylopectin branch chains form a starch granule ultrastructure. X-ray research has proved that starch granules are characterized by presence of interlacing amorphous and crystalline regions. In this case polymer orientation using stretching of the obtained end product influences on its physical and mechanical  indices which are increasing due to polymer orientation. For the purpose of packaging orientation of polymer films can solve such important problems as significant improvement of operational properties, creation of  thermosetting film materials, improvement of qualitative indices of the recycled film.Results of the conducted research have proved the fact that it is necessary to make changes in technology in order to increase biological degradability of the recycled packaging made from polymers and improve physical and mechanical indices. In this regard film production technology presupposes usage of such substances as stark and others which are characterized by rather large presence of branch chains of molecules and interlacing amorphous and crystalline regions. Such approach makes it possible to obtain after-use package which is strong and quickly degradable by micro-organisms.

Role of different biodegradable polymers on the permeability of ciprofloxacin

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Chandra Kanti Chakraborti

2014-01-01

Full Text Available Since permeability across biological membranes is a key factor in the absorption and distribution of drugs, drug permeation characteristics of three oral suspensions of ciprofloxacin were designed and compared. The three suspensions of ciprofloxacin were prepared by taking biodegradable polymers such as carbopol 934, carbopol 940, and hydroxypropyl methylcellulose (HPMC. The permeability study was performed by using a Franz diffusion cell through both synthetic cellulose acetate membrane and excised goat gastrointestinal membranes in acidic as well as alkaline pH. To know the permeability of drug from control/formulations through different membranes in acidic/alkaline pH, cumulative percentage drug permeation, apparent permeability (Papp, flux, and enhancement ratio (ER were calculated. Considering Papp and flux values of all formulations, it is evident that formulation containing HPMC was the most beneficial for improving permeation and diffusivity of ciprofloxacin even after 16 h. Hence, this preparation may be considered as the most suitable formulation to obtain prolonged release action of the drug. The ER values of all formulations, through excised goat intestinal mucosal membrane in alkaline pH, were higher than those formulations through goat stomach mucosal membrane in acidic pH. Enhancement ratio values of those formulations indicate that the permeability of the drug was more enhanced by the polymers in the intestinal part, leading to more bioavailability and prolonged action in that portion of the gastrointestinal tract. It may also be concluded from our results that HPMC containing formulation was the best suspension, which may show effective controlled release action. Even carbopol containing formulations might also produce controlled release action.

Synthesis, spectral characterization thermal stability, antimicrobial studies and biodegradation of starch–thiourea based biodegradable polymeric ligand and its coordination complexes with [Mn(II, Co(II, Ni(II, Cu(II, and Zn(II] metals

Directory of Open Access Journals (Sweden)

Nahid Nishat

2016-09-01

Full Text Available A biodegradable polymer was synthesized by the modification reaction of polymeric starch with thiourea which is further modified by transition metals, Mn(II, Co(II, Ni(II, Cu(II and Zn(II. All the polymeric compounds were characterized by (FT-IR spectroscopy, 1H NMR spectroscopy, 13C NMR spectroscopy, UV–visible spectra, magnetic moment measurements, thermogravimetric analysis (TGA and antibacterial activities. Polymer complexes of Mn(II, Co(II and Ni(II show octahedral geometry, while polymer complexes of Cu(II and Zn(II show square planar and tetrahedral geometry, respectively. The TGA revealed that all the polymer metal complexes are more thermally stable than their parental ligand. In addition, biodegradable studies of all the polymeric compounds were also carried out through ASTM-D-5338-93 standards of biodegradable polymers by CO2 evolution method which says that coordination decreases biodegradability. The antibacterial activity was screened with the agar well diffusion method against some selected microorganisms. Among all the complexes, the antibacterial activity of the Cu(II polymer–metal complex showed the highest zone of inhibition because of its higher stability constant.

Natural Phenol Polymers: Recent Advances in Food and Health Applications.

Science.gov (United States)

Panzella, Lucia; Napolitano, Alessandra

2017-04-14

Natural phenol polymers are widely represented in nature and include a variety of classes including tannins and lignins as the most prominent. Largely consumed foods are rich sources of phenol polymers, notably black foods traditionally used in East Asia, but other non-edible, easily accessible sources, e.g., seaweeds and wood, have been considered with increasing interest together with waste materials from agro-based industries, primarily grape pomace and other byproducts of fruit and coffee processing. Not in all cases were the main structural components of these materials identified because of their highly heterogeneous nature. The great beneficial effects of natural phenol-based polymers on human health and their potential in improving the quality of food were largely explored, and this review critically addresses the most interesting and innovative reports in the field of nutrition and biomedicine that have appeared in the last five years. Several in vivo human and animal trials supported the proposed use of these materials as food supplements and for amelioration of the health and production of livestock. Biocompatible and stable functional polymers prepared by peroxidase-catalyzed polymerization of natural phenols, as well as natural phenol polymers were exploited as conventional and green plastic additives in smart packaging and food-spoilage prevention applications. The potential of natural phenol polymers in regenerative biomedicine as additives of biomaterials to promote growth and differentiation of osteoblasts is also discussed.

Spatially discrete thermal drawing of biodegradable microneedles for vascular drug delivery.

Science.gov (United States)

Choi, Chang Kuk; Lee, Kang Ju; Youn, Young Nam; Jang, Eui Hwa; Kim, Woong; Min, Byung-Kwon; Ryu, WonHyoung

2013-02-01

Spatially discrete thermal drawing is introduced as a novel method for the fabrication of biodegradable microneedles with ultra-sharp tip ends. This method provides the enhanced control of microneedle shapes by spatially controlling the temperature of drawn polymer as well as drawing steps and speeds. Particular focus is given on the formation of sharp tip ends of microneedles at the end of thermal drawing. Previous works relied on the fracture of polymer neck by fast drawing that often causes uncontrolled shapes of microneedle tips. Instead, this approach utilizes the surface energy of heated polymer to form ultra-sharp tip ends. We have investigated the effect of such temperature control, drawing speed, and drawing steps in thermal drawing process on the final shape of microneedles using biodegradable polymers. XRD analysis was performed to analyze the effect of thermal cycle on the biodegradable polymer. Load-displacement measurement also showed the dependency of mechanical strengths of microneedles on the microneedle shapes. Ex vivo vascular tissue insertion and drug delivery demonstrated microneedle insertion to tunica media layer of canine aorta and drug distribution in the tissue layer. Copyright © 2012 Elsevier B.V. All rights reserved.

Abiotic and biotic degradation of oxo-biodegradable plastic bags by Pleurotus ostreatus.

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José Maria Rodrigues da Luz

Full Text Available In this study, we evaluated the growth of Pleurotus ostreatus PLO6 using oxo-biodegradable plastics as a carbon and energy source. Oxo-biodegradable polymers contain pro-oxidants that accelerate their physical and biological degradation. These polymers were developed to decrease the accumulation of plastic waste in landfills. To study the degradation of the plastic polymers, oxo-biodegradable plastic bags were exposed to sunlight for up to 120 days, and fragments of these bags were used as substrates for P. ostreatus. We observed that physical treatment alone was not sufficient to initiate degradation. Instead, mechanical modifications and reduced titanium oxide (TiO2 concentrations caused by sunlight exposure triggered microbial degradation. The low specificity of lignocellulolytic enzymes and presence of endomycotic nitrogen-fixing microorganisms were also contributing factors in this process.

Abiotic and biotic degradation of oxo-biodegradable plastic bags by Pleurotus ostreatus.

Science.gov (United States)

da Luz, José Maria Rodrigues; Paes, Sirlaine Albino; Bazzolli, Denise Mara Soares; Tótola, Marcos Rogério; Demuner, Antônio Jacinto; Kasuya, Maria Catarina Megumi

2014-01-01

In this study, we evaluated the growth of Pleurotus ostreatus PLO6 using oxo-biodegradable plastics as a carbon and energy source. Oxo-biodegradable polymers contain pro-oxidants that accelerate their physical and biological degradation. These polymers were developed to decrease the accumulation of plastic waste in landfills. To study the degradation of the plastic polymers, oxo-biodegradable plastic bags were exposed to sunlight for up to 120 days, and fragments of these bags were used as substrates for P. ostreatus. We observed that physical treatment alone was not sufficient to initiate degradation. Instead, mechanical modifications and reduced titanium oxide (TiO2) concentrations caused by sunlight exposure triggered microbial degradation. The low specificity of lignocellulolytic enzymes and presence of endomycotic nitrogen-fixing microorganisms were also contributing factors in this process.

Abiotic and Biotic Degradation of Oxo-Biodegradable Plastic Bags by Pleurotus ostreatus

Science.gov (United States)

da Luz, José Maria Rodrigues; Paes, Sirlaine Albino; Bazzolli, Denise Mara Soares; Tótola, Marcos Rogério; Demuner, Antônio Jacinto; Kasuya, Maria Catarina Megumi

2014-01-01

In this study, we evaluated the growth of Pleurotus ostreatus PLO6 using oxo-biodegradable plastics as a carbon and energy source. Oxo-biodegradable polymers contain pro-oxidants that accelerate their physical and biological degradation. These polymers were developed to decrease the accumulation of plastic waste in landfills. To study the degradation of the plastic polymers, oxo-biodegradable plastic bags were exposed to sunlight for up to 120 days, and fragments of these bags were used as substrates for P. ostreatus. We observed that physical treatment alone was not sufficient to initiate degradation. Instead, mechanical modifications and reduced titanium oxide (TiO2) concentrations caused by sunlight exposure triggered microbial degradation. The low specificity of lignocellulolytic enzymes and presence of endomycotic nitrogen-fixing microorganisms were also contributing factors in this process. PMID:25419675

Release behavior of drugs from various natural gums and polymers.

Science.gov (United States)

Singh, Anupama; Sharma, Pramod Kumar; Malviya, Rishabha

2011-01-01

Polymers are the high molecular weight compounds of natural or synthetic origin, widely used in drug delivery of formulations. These polymers are further classified as hydrophilic or hydrophobic in nature. Depending upon this characteristic, polymers exhibit different release behavior in different media. This property plays an important role in the selection of polymers for controlled, sustained or immediate release formulations. The review highlights the literatures related to the research made on several polymers regarding the release kinetics which made them a novel approach for modifying the action of the particular formulation.

Health status of cows fed maize silage covered with oxo-biodegradable foil

OpenAIRE

Piotr SZTERK; Piotr DORSZEWSKI; Małgorzata GRABOWICZ; Lucyna PODKÓWKA

2017-01-01

In agricultural practice, silage production uses pure, low density polyethylene foil. This foil, after use, becomes farm waste, having a negative impact on the environment. Instead of conventional foil, an environmentally safe biodegradable foil can be used, made from naturally occurring polymers or from synthetic multiparticulates, easily degradable by microorganisms. Silage covered with this type of foil should be safe for animal health. The purpose of the study was to determine whether oxo...

Biodegradable poly lactone-family polymer and their applications in medical field

International Nuclear Information System (INIS)

Wang, S.; Bei, J.

2005-01-01

Poly lactone-family polymers such as poly lactide, poly glycolide and polycaprolactone are kind aliphatic polyester. Since they can degrade by hydrolysis reaction under all the ph condition and possess biocompatibility, biodegradability and other good properties, especially they included not peptide bond in their molecules, they are non-antigen and non-immunization, as well as have no-toxicity and no-stimulation. So they are interested biomaterials and very useful in medical field. However the properties of all of the homo-poly lactones can not be changed in a large range, the limited properties result in limited applications of these homo-poly lactones. Based on macromolecular design, a series of copolylactones such as poly(lactide-co-glycolide) (PLGA), poly(glycolide-co-lactide-co-caprolactone) tri- component copolymer (PGLC), tri- and multi-block poly lactide/poly(ethylene oxide) copolymer (TPLE and BPLE), as well as polycaprolactone/poly lactide/poly(ethylene oxide) copolymer (PCEL) et al were synthesized by copolymerization among various lactone monomers or lactone monomers with poly(ethylene glycol). These copolylactones have wide range of degradation life from several months to years and different mechanical properties. After plasma treatment the surface property of the copolylactones were improved further and cell affinity of the copolylactones was improved obviously. The applications of these poly lactone-family polymers in medical field for used as drug carrier in drug delivery system, and as cell scaffold in tissue engineering were discussed

Self-assembly of biodegradable copolyester and reactive HPMA-based polymers into nanoparticles as an alternative stealth drug delivery system

Czech Academy of Sciences Publication Activity Database

Jäger, Eliezer; Jäger, Alessandro; Etrych, Tomáš; Giacomelli, F. C.; Chytil, Petr; Jigounov, Alexander; Putaux, J.-L.; Říhová, Blanka; Ulbrich, Karel; Štěpánek, Petr

2012-01-01

Roč. 8, č. 37 (2012), s. 9563-9575 ISSN 1744-683X R&D Projects: GA AV ČR IAAX00500803; GA ČR GAP208/10/1600 Institutional research plan: CEZ:AV0Z40500505; CEZ:AV0Z50200510 Institutional support: RVO:61389013 ; RVO:61388971 Keywords : biodegradable nanoparticles * light scattering from polymer nanoparticles * doxorubicin drug release Subject RIV: CF - Physical ; Theoretical Chemistry; EC - Immunology (MBU-M) Impact factor: 3.909, year: 2012

The increase of compressive strength of natural polymer modified concrete with Moringa oleifera

Science.gov (United States)

Susilorini, Rr. M. I. Retno; Santosa, Budi; Rejeki, V. G. Sri; Riangsari, M. F. Devita; Hananta, Yan's. Dianaga

2017-03-01

Polymer modified concrete is one of some concrete technology innovations to meet the need of strong and durable concrete. Previous research found that Moringa oleifera can be applied as natural polymer modifiers into mortars. Natural polymer modified mortar using Moringa oleifera is proven to increase their compressive strength significantly. In this resesearch, Moringa oleifera seeds have been grinded and added into concrete mix for natural polymer modified concrete, based on the optimum composition of previous research. The research investigated the increase of compressive strength of polymer modified concrete with Moringa oleifera as natural polymer modifiers. There were 3 compositions of natural polymer modified concrete with Moringa oleifera referred to previous research optimum compositions. Several cylinder of 10 cm x 20 cm specimens were produced and tested for compressive strength at age 7, 14, and, 28 days. The research meets conclusions: (1) Natural polymer modified concrete with Moringa oleifera, with and without skin, has higher compressive strength compared to natural polymer modified mortar with Moringa oleifera and also control specimens; (2) Natural polymer modified concrete with Moringa oleifera without skin is achieved by specimens contains Moringa oleifera that is 0.2% of cement weight; and (3) The compressive strength increase of natural polymer modified concrete with Moringa oleifera without skin is about 168.11-221.29% compared to control specimens

Reactive electrospinning and biodegradation of cross-linked methacrylated polycarbonate nanofibers

Energy Technology Data Exchange (ETDEWEB)

Wu Ruizhi; Zhang Jianfeng; Fan Yuwei; Xu Xiaoming [Department of Comprehensive Dentistry and Biomaterials, Louisiana State University Health Sciences Center, 1100 Florida Avenue, Box 137, New Orleans, LA 70119 (United States); Stoute, Diana; Lallier, Thomas, E-mail: xxu@lsuhsc.edu [Department of Cell Biology and Anatomy, Louisiana State University Health Science Center, 1100 Florida Avenue, Box 137, New Orleans, LA 70119 (United States)

2011-06-15

The objectives of this study were to fabricate cross-linked biodegradable polycarbonate nanofibers and to investigate their biodegradability by different enzymes. Poly(2,3-dihydroxycarbonate) was synthesized from naturally occurring l-tartaric acid. The hydroxyl groups on the functional polycarbonate were converted to methacrylate groups to enable the polymer to cross-link under UV irradiation. Smooth cross-linked methacrylated polycarbonate nanofibers (300-1800 nm) were fabricated by a reactive electrospinning process with in situ UV radiation from a mixed solution of linear methacrylated polycarbonate (MPC) and poly(ethylene oxide) (PEO) (MPC:PEO = 9:1) in methanol/chloroform (50/50). These cross-linked nanofibers have shown excellent solvent resistance and their solubility decreases with increasing degree of cross-linking. The thermal properties of linear and cross-linked polycarbonate nanofibers were investigated by differential scanning calorimetry and thermogravimetric analysis. The cross-linked polycarbonate nanofibers show no melting point below 200 {sup 0}C and their decomposition temperature increases with increasing cross-linking degree. Their biodegradation products by five different enzymes were analyzed using liquid chromatography-mass spectrometry (LC-MS). The biodegradability of the polycarbonate nanofibers decreases with increasing cross-linking degree. These nanofibers were found to support human fibroblast survival and to promote cell attachment. This study demonstrates that cross-linked biodegradable polycarbonate nanofibers with different chemical properties and biodegradability can be fabricated using the novel reactive electrospinning technology to meet the needs of different biomedical applications.

Researches on the development of new composite materials complete / partially biodegradable using natural textile fibers of new vegetable origin and those recovered from textile waste

Science.gov (United States)

Todor, M. P.; Bulei, C.; Heput, T.; Kiss, I.

2018-01-01

The objective of the research is to develop new fully / partially biodegradable composite materials by using new natural fibers and those recovered from various wastes. Thus, the research aims to obtain some composites with matrix of various types of polymeric materials and the reinforcement phase of textile materials (of different natures, morphologies and composites) so that the resulting products to be (bio)degradable. The textile inserts used as raffle are ecological, non-toxic and biodegradable and they contain (divided or in combination) bast fibers (flax, hemp, jute) and other vegetable fibers (cotton, wool) as plain yarn or fabric, which can replace fibers of glass commonly used in polymeric composites. The main activities described in this article are carried out during the first phase of the research (phase I - initiation of research) and they are oriented towards the choice of types of textile inserts from which the composites will be obtained (the materials needed for the raffle), the choice of the types of polymers (the necessary materials for matrices) and choosing the variants of composites with different types and proportions of the constituent content (proposals and working variants) and choosing the right method for obtaining samples of composite materials (realization technology). The purpose of the research is to obtain composite materials with high structural, thermo-mechanical and / or tribological performances, according to ecological norms and international requirements in order to replace the existing classical materials, setting up current, innovative and high performance solutions, for applications in top areas such as automotive industry and not only.

Biodegradation and Osteosarcoma Cell Cultivation on Poly(aspartic acid) Based Hydrogels.

Science.gov (United States)

Juriga, Dávid; Nagy, Krisztina; Jedlovszky-Hajdú, Angéla; Perczel-Kovách, Katalin; Chen, Yong Mei; Varga, Gábor; Zrínyi, Miklós

2016-09-14

Development of novel biodegradable and biocompatible scaffold materials with optimal characteristics is important for both preclinical and clinical applications. The aim of the present study was to analyze the biodegradability of poly(aspartic acid)-based hydrogels, and to test their usability as scaffolds for MG-63 osteoblast-like cells. Poly(aspartic acid) was fabricated from poly(succinimide) and hydrogels were prepared using natural amines as cross-linkers (diaminobutane and cystamine). Disulfide bridges were cleaved to thiol groups and the polymer backbone was further modified with RGD sequence. Biodegradability of the hydrogels was evaluated by experiments on the base of enzymes and cell culture medium. Poly(aspartic acid) hydrogels possessing only disulfide bridges as cross-links proved to be degradable by collagenase I. The MG-63 cells showed healthy, fibroblast-like morphology on the double cross-linked and RGD modified hydrogels. Thiolated poly(aspartic acid) based hydrogels provide ideal conditions for adhesion, survival, proliferation, and migration of osteoblast-like cells. The highest viability was found on the thiolated PASP gels while the RGD motif had influence on compacted cluster formation of the cells. These biodegradable and biocompatible poly(aspartic acid)-based hydrogels are promising scaffolds for cell cultivation.

Identification of market bags composition for biodegradable and oxo-biodegradable samples through thermal analysis in inert and oxidizer atmosphere

International Nuclear Information System (INIS)

Finzi-Quintao, Cristiane M.; Novack, Katia M.

2015-01-01

Plastic films used to make market bags are based on polymers such as polyethylene, polystyrene and polypropylene, these materials require a long time to degrade in the environment. The alternative technologies of polymers have been developed to reduce the degradation time and the impact on the environment caused by the conventional materials, using pro-degrading additives or by the development biodegradable polymers. In Brazil, the laws of some municipalities require the use of biodegradable material in the production of market bags but the absence of specific surveillance policies makes its chemical composition unknown. In this paper, we analyzed 7 samples that was obtained from a a trading company and commercial market of Belo Horizonte . The samples were characterized by TGA / DTA , XRF , FTIR and MEV which allowed the identification and evaluation of the thermal behavior of the material in inert and oxidizing atmosphere. (author)

A Mechanistic Model for Drug Release in PLGA Biodegradable Stent Coatings Coupled with Polymer Degradation and Erosion

Science.gov (United States)

Zhu, Xiaoxiang; Braatz, Richard D.

2015-01-01

Biodegradable poly(D,L-lactic-co-glycolic acid) (PLGA) coating for applications in drug-eluting stents has been receiving increasing interest as a result of its unique properties compared with biodurable polymers in delivering drug for reducing stents-related side effects. In this work, a mathematical model for describing the PLGA degradation and erosion and coupled drug release from PLGA stent coating is developed and validated. An analytical expression is derived for PLGA mass loss that predicts multiple experimental studies in the literature. An analytical model for the change of the number-average degree of polymerization (or molecular weight) is also derived. The drug transport model incorporates simultaneous drug diffusion through both the polymer solid and the liquid-filled pores in the coating, where an effective drug diffusivity model is derived taking into account factors including polymer molecular weight change, stent coating porosity change, and drug partitioning between solid and aqueous phases. The model is used to describe in vitro sirolimus release from PLGA stent coating, and demonstrates the significance of simultaneous sirolimus release via diffusion through both polymer solid and pore space. The proposed model is compared to existing drug transport models, and the impact of model parameters, limitations and possible extensions of the model are also discussed. PMID:25345656

Radiation processing of natural polymers using low energy electron beam

International Nuclear Information System (INIS)

Kume, Tamikazu

2004-01-01

Radiation processing is widely used in Japan and the economic scale of radiation application amounted to about 71 b$ (ratio relative to GDP: 1.7%) in total. It consisted of 60 b$ (85%) in industry, 10 b$ (14%) in medicine and 1 b$ (1%) in agriculture. Irradiation using gamma-ray from 60 Co and electron beam is commercially used for the sterilization and modification of materials. Utilization of natural polymers by radiation has been investigated for recycling the natural resources and reducing the environmental pollution. Polysaccharides such as chitosan, sodium alginate, carrageenan, cellulose, pectin were easily degraded by irradiation and induced various kinds of biological activities, i.e. anti-bacterial activity, elicitor activity, plant growth promotion, suppression of environmental stress on plants. Radiation degraded chitosan was effective to enhance the growth of plants in tissue culture. Low energy electron beam (EB) irradiation has a variety of applications and good safety. A self-shielded low energy electron accelerator system needs an initial investment much lower than a 60 Co facility. It was demonstrated that the liquid sample irradiation system using low energy EB was effective not only for the preparation of degraded polysaccharides but also for radiation vulcanization of natural rubber latex (RVNRL). Some carbohydrate derivatives, carboxymethylcellulose (CMC), carboxymethyl-starch and carboxymethyl-chitin/chitosan, can be crosslinked under certain radiation condition and produced the biodegradable hydrogel for medical and agricultural use. Treatment of soybean seeds by low energy EB enhanced the growth and the number of rhizobia on the root. (author)

Microencapsulation of chemotherapeutics into monodisperse and tunable biodegradable polymers via electrified liquid jets: control of size, shape, and drug release.

Science.gov (United States)

Fattahi, Pouria; Borhan, Ali; Abidian, Mohammad Reza

2013-09-06

This paper describes microencapsulation of antitumor agent 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU, Carmustine) into biodegradable polymer poly(lactic-co-glycolic) acid (PLGA) using an electrojetting technique. The resulting BCNU-loaded PLGA microcapsules have significantly higher drug encapsulation efficiency, more tunable drug loading capacity, and (3) narrower size distribution than those generated using other encapsulation methods. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Antimicrobial activity of biodegradable polysaccharide and protein-based films containing active agents.

Science.gov (United States)

Kuorwel, Kuorwel K; Cran, Marlene J; Sonneveld, Kees; Miltz, Joseph; Bigger, Stephen W

2011-04-01

Significant interest has emerged in the introduction of food packaging materials manufactured from biodegradable polymers that have the potential to reduce the environmental impacts associated with conventional packaging materials. Current technologies in active packaging enable effective antimicrobial (AM) packaging films to be prepared from biodegradable materials that have been modified and/or blended with different compatible materials and/or plasticisers. A wide range of AM films prepared from modified biodegradable materials have the potential to be used for packaging of various food products. This review examines biodegradable polymers derived from polysaccharides and protein-based materials for their potential use in packaging systems designed for the protection of food products from microbial contamination. A comprehensive table that systematically analyses and categorizes much of the current literature in this area is included in the review.

Polímeros biodegradáveis - uma solução parcial para diminuir a quantidade dos resíduos plásticos Biodegradable polymers - a partial way for decreasing the amount of plastic waste

Directory of Open Access Journals (Sweden)

Sandra Mara Martins Franchetti

2006-07-01

Full Text Available The large use of plastics has generated a waste deposit problem. Today plastic wastes represent 20% in volume of the total waste in the municipal landfills. To solve the disposal problem of plastics methods have been employed such as incineration, recycling, landfill disposal, biodegradation and the use of biodegradable polymers. Incineration of plastic wastes provokes pollution due to the production of poisonous gases. Recycling is important to reduce final costs of plastic materials, but is not enough in face of the amount of discarded plastic. In landfills plastic wastes remain undegraded for a long time, causing space and pollution problems. Biodegradation is a feasible method to treat some plastics, but intensive research is necessary to find conditions for the action of microorganisms. All of these methods are important and the practical application of each one depends on the type and amount of the plastic wastes and the environmental conditions. Therefore, a great deal of research has focused on developing biodegradable plastics and its application because it is an important way for minimizing the effect of the large volume of plastic waste discarded in the world.

Mechanical properties and osteocompatibility of novel biodegradable alanine based polyphosphazenes: Side group effects.

Science.gov (United States)

Sethuraman, Swaminathan; Nair, Lakshmi S; El-Amin, Saadiq; Nguyen, My-Tien; Singh, Anurima; Krogman, Nick; Greish, Yaser E; Allcock, Harry R; Brown, Paul W; Laurencin, Cato T

2010-06-01

The versatility of polymers for tissue regeneration lies in the feasibility to modulate the physical and biological properties by varying the side groups grafted to the polymers. Biodegradable polyphosphazenes are high-molecular-weight polymers with alternating nitrogen and phosphorus atoms in the backbone. This study is the first of its kind to systematically investigate the effect of side group structure on the compressive strength of novel biodegradable polyphosphazene based polymers as potential materials for tissue regeneration. The alanine polyphosphazene based polymers, poly(bis(ethyl alanato) phosphazene) (PNEA), poly((50% ethyl alanato) (50% methyl phenoxy) phosphazene) (PNEA(50)mPh(50)), poly((50% ethyl alanato) (50% phenyl phenoxy) phosphazene) (PNEA(50)PhPh(50)) were investigated to demonstrate their mechanical properties and osteocompatibility. Results of mechanical testing studies demonstrated that the nature and the ratio of the pendent groups attached to the polymer backbone play a significant role in determining the mechanical properties of the resulting polymer. The compressive strength of PNEA(50)PhPh(50) was significantly higher than poly(lactide-co-glycolide) (85:15 PLAGA) (p<0.05). Additional studies evaluated the cellular response and gene expression of primary rat osteoblast cells on PNEA, PNEA(50)mPh(50) and PNEA(50)PhPh(50) films as candidates for bone tissue engineering applications. Results of the in vitro osteocompatibility evaluation demonstrated that cells adhere, proliferate, and maintain their phenotype when seeded directly on the surface of PNEA, PNEA(50)mPh(50), and PNEA(50)PhPh(50). Moreover, cells on the surface of the polymers expressed type I collagen, alkaline phosphatase, osteocalcin, osteopontin, and bone sialoprotein, which are characteristic genes for osteoblast maturation, differentiation, and mineralization. Copyright 2009 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

A Review on Recent Advances in Stabilizing Peptides/Proteins upon Fabrication in Hydrogels from Biodegradable Polymers

Directory of Open Access Journals (Sweden)

Faisal Raza

2018-01-01

Full Text Available Hydrogels evolved as an outstanding carrier material for local and controlled drug delivery that tend to overcome the shortcomings of old conventional dosage forms for small drugs (NSAIDS and large peptides and proteins. The aqueous swellable and crosslinked polymeric network structure of hydrogels is composed of various natural, synthetic and semisynthetic biodegradable polymers. Hydrogels have remarkable properties of functionality, reversibility, sterilizability, and biocompatibility. All these dynamic properties of hydrogels have increased the interest in their use as a carrier for peptides and proteins to be released slowly in a sustained manner. Peptide and proteins are remarkable therapeutic agents in today’s world that allow the treatment of severe, chronic and life-threatening diseases, such as diabetes, rheumatoid arthritis, hepatitis. Despite few limitations, hydrogels provide fine tuning of proteins and peptides delivery with enormous impact in clinical medicine. Novels drug delivery systems composed of smart peptides and molecules have the ability to drive self-assembly and form hydrogels at physiological pH. These hydrogels are significantly important for biological and medical fields. The primary objective of this article is to review current issues concerned with the therapeutic peptides and proteins and impact of remarkable properties of hydrogels on these therapeutic agents. Different routes for pharmaceutical peptides and proteins and superiority over other drugs candidates are presented. Recent advances based on various approaches like self-assembly of peptides and small molecules to form novel hydrogels are also discussed. The article will also review the literature concerning the classification of hydrogels on a different basis, polymers used, “release mechanisms” their physical and chemical characteristics and diverse applications.

Matrix-assisted laser desorption/ionization mass spectrometric analysis of aliphatic biodegradable photoluminescent polymers using new ionic liquid matrices.

Science.gov (United States)

Serrano, Carlos A; Zhang, Yi; Yang, Jian; Schug, Kevin A

2011-05-15

In this study, two novel ionic liquid matrices (ILMs), N,N-diisopropylethylammonium 3-oxocoumarate and N,N-diisopropylethylammonium dihydroxymonooxoacetophenoate, were tested for the structural elucidation of recently developed aliphatic biodegradable polymers by matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS). The polymers, formed by a condensation reaction of three components, citric acid, octane diol, and an amino acid, are fluorescent, but the exact mechanism behind their luminescent properties has not been fully elucidated. In the original studies, which introduced the polymer class (J. Yang et al., Proc. Natl. Acad. Sci. USA 2009, 106, 10086-10091), a hyper-conjugated cyclic structure was proposed as the source for the photoluminescent behavior. With the use of the two new ILMs, we present evidence that supports the presence of the proposed cyclization product. In addition, the new ILMs, when compared with a previously established ILM, N,N-diisopropylethylammonium α-cyano-3-hydroxycinnimate, provided similar signal intensities and maintained similar spectral profiles. This research also established that the new ILMs provided good spot-to-spot reproducibility and high ionization efficiency compared with corresponding crystalline matrix preparations. Many polymer features revealed through the use of the ILMs could not be observed with crystalline matrices. Ultimately, the new ILMs highlighted the composition of the synthetic polymers, as well as the loss of water that was expected for the formation of the proposed cyclic structure on the polymer backbone. Copyright © 2011 John Wiley & Sons, Ltd.

Biodegradable compounds: Rheological, mechanical and thermal properties

Science.gov (United States)

Nobile, Maria Rossella; Lucia, G.; Santella, M.; Malinconico, M.; Cerruti, P.; Pantani, R.

2015-12-01

Recently great attention from industry has been focused on biodegradable polyesters derived from renewable resources. In particular, PLA has attracted great interest due to its high strength and high modulus and a good biocompatibility, however its brittleness and low heat distortion temperature (HDT) restrict its wide application. On the other hand, Poly(butylene succinate) (PBS) is a biodegradable polymer with a low tensile modulus but characterized by a high flexibility, excellent impact strength, good thermal and chemical resistance. In this work the two aliphatic biodegradable polyesters PBS and PLA were selected with the aim to obtain a biodegradable material for the industry of plastic cups and plates. PBS was also blended with a thermoplastic starch. Talc was also added to the compounds because of its low cost and its effectiveness in increasing the modulus and the HDT of polymers. The compounds were obtained by melt compounding in a single screw extruder and the rheological, mechanical and thermal properties were investigated. The properties of the two compounds were compared and it was found that the values of the tensile modulus and elongation at break measured for the PBS/PLA/Talc compound make it interesting for the production of disposable plates and cups. In terms of thermal resistance the compounds have HDTs high enough to contain hot food or beverages. The PLA/PBS/Talc compound can be, then, considered as biodegradable substitute for polystyrene for the production of disposable plates and cups for hot food and beverages.

Biodegradation study of enzymatically catalyzed interpenetrating polymer network: Evaluation of agrochemical release and impact on soil fertility

Directory of Open Access Journals (Sweden)

Saruchi

2016-03-01

Full Text Available A novel interpenetrating polymer network (IPN has been synthesized through enzymatic initiation using lipase as initiator, glutaraldehyde as cross-linker, acrylic acid as primary monomer and acrylamide as secondary monomer. Biodegradability of synthesized interpenetrating polymer network was studied through soil burial and composting methods. Synthesized hydrogel was completely degraded within 70 days using composting method, while it was 86.03% degraded within 77 days using soil burial method. This was confirmed by Fourier transform Infrared spectroscopy (FTIR and Scanning electron microscopy (SEM techniques. Synthesized interpenetrating polymer network hydrogel was used as a device for controlled release of urea and also act as water releasing device. Their impact on soil fertility and plant growth was also studied. The initial diffusion coefficient has a greater value than the later diffusion coefficient indicating a higher fertilizer release rate during the early stage. Fertilizer release kinetic was also studied which showed Non-Fickian diffusion behavior, as the rate of fertilizer release was comparable to the relaxation time of the synthesized matrix. Synthesized IPN enhance the water uptake capacity up to 6.2% and 7.2% in sandy loam and clay soil, respectively.

State-of-the-art of biodegradable composite materials

International Nuclear Information System (INIS)

Baley, Ch.; Grohens, Y.; Pillin, I.

2004-01-01

Nowadays, the market demand for environment friendly materials is in strong growth. The biodegradable composites (biodegradable fibres and polymers) mainly extracted from renewable resources will be a major contributor to the production of new industrial high performance products partially solving the problem of waste management. At the end of the lifetime, a structural bio-composite could be be crushed and recycled through a controlled industrial composting process. This the state-of-the-art report focuses on the biopolymers the vegetable fibres properties, the mechanisms of biodegradation and the examples of biodegradable composites. Eco-design of new products requires these new materials for which a life cycle analysis is nevertheless necessary to validate their environmental benefits. (authors)

Bioactivity of freeze-dried platelet-rich plasma in an adsorbed form on a biodegradable polymer material.

Science.gov (United States)

Nakajima, Yu; Kawase, Tomoyuki; Kobayashi, Mito; Okuda, Kazuhiro; Wolff, Larry F; Yoshie, Hiromasa

2012-01-01

Owing to the necessity for the immediate preparation from patients' blood, autologous platelet-rich plasma (PRP) limits its clinical applicability. To address this concern and respond to emergency care and other unpredictable uses, we have developed a freeze-dried PRP in an adsorbed form on a biodegradable polymer material (Polyglactin 910). On the polymer filaments of PRP mesh, which was prepared by coating the polymer mesh with human fresh PRP and subsequent freeze-drying, platelets were incorporated, and related growth factors were preserved at high levels. This new PRP mesh preparation significantly and reproducibly stimulated the proliferation of human periodontal ligament cells in vitro and neovascularization in a chorioallantoic membrane assay. A full-thickness skin defect model in a diabetic mouse demonstrated the PRP mesh, although prepared from human blood, substantially facilitated angiogenesis, granulation tissue formation, and re-epithelialization without inducing severe inflammation in vivo. These data demonstrate that our new PRP mesh preparation functions as a bioactive material to facilitate tissue repair/regeneration. Therefore, we suggest that this bioactive material, composed of allogeneic PRP, could be clinically used as a promising alternative in emergency care or at times when autologous PRP is not prepared immediately before application.

Application of natural and synthetic polymers in a production of paper

Directory of Open Access Journals (Sweden)

Jovanović Slobodan

2007-01-01

Full Text Available This work gives the review of most frequently used natural and synthetic polymers in production of paper, board and cardboard. Physical and chemical interaction of natural and synthetic polymers with cellulose fibers, and thus the way these polymers influence the improvement of both production process and the paper characteristics, have been presented.

Natural and synthetic biomaterials for controlled drug delivery.

Science.gov (United States)

Kim, Jang Kyoung; Kim, Hyung Jin; Chung, Jee-Young; Lee, Jong-Hwan; Young, Seok-Beom; Kim, Yong-Hee

2014-01-01

A wide variety of delivery systems have been developed and many products based on the drug delivery technology are commercially available. The development of controlled-release technologies accelerated new dosage form design by altering pharmacokinetic and pharmacodynamics profiles of given drugs, resulting in improved efficacy and safety. Various natural or synthetic polymers have been applied to make matrix, reservoir or implant forms due to the characteristics of polymers, especially ease of control for modifications of biocompatibility, biodegradation, porosity, charge, mechanical strength and hydrophobicity/hydrophilicity. Hydrogel is a hydrophilic, polymeric network capable of imbibing large amount of water and biological fluids. This review article introduces various applications of natural and synthetic polymer-based hydrogels from pharmaceutical, biomedical and bioengineering points of view.

Preparation and Characterization of PLA-Starch Biodegradable Composites Via Radiation Processing

Energy Technology Data Exchange (ETDEWEB)

Hemvichian, K.; Suwanmala, P. [Thailand Institute of Nuclear Technology (TINT) (Thailand); Kungsumrith, W. [Department of Industrial Engineering, Faculty of Engineering, Thammasat University (TU) (Thailand); Pongprayoon, T. [Department of Chemical Engineering, Faculty of Engineering, King Mongkut’s University of Technology North Bangkok (KMUTNB), Bangkok (Thailand)

2011-07-01

This research project aims to apply the use of radiation processing to prepare biodegradable composites from poly(lactic acid) or polylactide (PLA) and cassava starch. Cassava starch, a natural polymer that is inexpensive and abundant, especially in Thailand, will be used as starting material. Functional group of cassava starch will be modified first in order to render starch more compatible with PLA. The monomer with desired functional groups will be grafted onto the backbone of starch via radiation-induced grafting polymerization. Different parameters will be examined to determine the optimum conditions for the grafting polymerization. The modified starch will subsequently be blended with PLA, with and without clay, to form biodegradable composites. In order to further improve the thermal properties, the blends and their composites will be subjected to radiation to induce crosslinking between the molecules of PLA and starch derivatives. (author)

Preparation and Characterization of PLA-Starch Biodegradable Composites Via Radiation Processing

International Nuclear Information System (INIS)

Hemvichian, K.; Suwanmala, P.; Kungsumrith, W.; Pongprayoon, T.

2011-01-01

This research project aims to apply the use of radiation processing to prepare biodegradable composites from poly(lactic acid) or polylactide (PLA) and cassava starch. Cassava starch, a natural polymer that is inexpensive and abundant, especially in Thailand, will be used as starting material. Functional group of cassava starch will be modified first in order to render starch more compatible with PLA. The monomer with desired functional groups will be grafted onto the backbone of starch via radiation-induced grafting polymerization. Different parameters will be examined to determine the optimum conditions for the grafting polymerization. The modified starch will subsequently be blended with PLA, with and without clay, to form biodegradable composites. In order to further improve the thermal properties, the blends and their composites will be subjected to radiation to induce crosslinking between the molecules of PLA and starch derivatives. (author)

Biodegradable films and spray coatings as eco-friendly alternative to petro-chemical derived mulching films

Directory of Open Access Journals (Sweden)

G. Vox

2013-09-01

Full Text Available The use of plastic mulching films in horticulture causes the serious drawback of huge amount of wastes to be disposed of at the end of their lifetime. Several pre-competitive research products based on raw materials coming from renewable sources were recently developed to be used as biodegradable materials for soil mulching. Biodegradable materials are designed in order both to retain their mechanical and physical properties during their using time and to degrade at the end of their lifetime. These materials can be integrated directly in the soil in order to biodegrade because the bacterial flora transforms them in carbon dioxide or methane, water and biomass. The innovative materials can be obtained using natural polymers, such as starch, cellulose, chitosan, alginate and glucomannan. Biodegradable extruded mulching films were performed by means of thermo-plasticizing process. Spray mulch coatings were realized directly in field, by spraying water solutions based on natural polysaccharides, thus covering the cultivated soil with a protective thin geo-membrane. In this paper an overview on the formulation development, processing understanding, field performance, mechanical and radiometric properties of these innovative materials for soil mulching is presented. In field the biodegradable mulching films showed suitable mechanical properties if compared to the low density polyethylene films. The radiometric properties and their effect on the temperature condition and on weed control in the mulched soil were evaluated too. At the end of their lifetime the biodegradable materials were shattered and buried into the soil together with plants.

Biodegradability Study of the Blend Film of High Density Polyethylene and Poly(lactic acid Disposable Packages Flake

Directory of Open Access Journals (Sweden)

Elahe Baghi Neirizi

2016-03-01

Full Text Available One of the major concerns of using a non-biodegradable polymer product is its disposal at the end of its life cycle. Development of biodegradable plastics promises an alternative solution to combat this problem. Blending of poly(lactic acid with non-biodegradable polymers is a practical and economical method for modifying the biodegradability properties of non-biodegradable polymers. In this study, soil biodegradability of the blends of high density polyethylene (HDPE and variable amounts of recycled poly(lactic acid (r-PLA plastic flakes at 0, 5, 10, 20, 30, 40 and 50 wt% was studied. The behavior of the force-elongation profile of the blends having r-PLA content of lower than 30 wt% was approximately the same as that of pure HDPE while, it was completely different for the other blends. Tearing force and elongation-at-yield-point of the blends films with the 20 to 50 wt% r-PLA were decreased significantly after 60 days of soil biodegradability test. Morphological study showed that biodegradability of the blend films at surface of the samples (deep pores and grooves was increased with extended biodegradability time and higher r-PLA content, while, this variation was significant for the blend films of more than 20 wt% r-PLA content. Thermal properties evaluation by differential scanning calorimetry (DSC curves indicated that the glass transition temperature and enthalpy peaks during the heating stage were eliminated with increasing the biodegradability testing time. Also, reduction in the crystallinity degree of the r-PLA component with increasing the biodegradability testing time coincided with the earlier results.

Natural polymers, gums and mucilages as excipients in drug delivery.

Science.gov (United States)

Kumar, Shobhit; Gupta, Satish Kumar

2012-01-01

Use of natural polymers, gums and mucilages in drug delivery systems has been weighed down by the synthetic materials. Natural based excipients offered advantages such as non-toxicity, less cost and abundantly availablity. Aqueous solubility of natural excipients plays an important role in their selection for designing immediate, controlled or sustained release formulations. This review article provide an overview of natural gum, polymers and mucilages as excipients in dosage forms as well as novel drug delivery systems.

Assessing the biodegradability of microparticles disposed down the drain.

Science.gov (United States)

McDonough, Kathleen; Itrich, Nina; Casteel, Kenneth; Menzies, Jennifer; Williams, Tom; Krivos, Kady; Price, Jason

2017-05-01

Microparticles made from naturally occurring materials or biodegradable plastics such as poly(3-hydroxy butyrate)-co-(3-hydroxy valerate), PHBV, are being evaluated as alternatives to microplastics in personal care product applications but limited data is available on their ultimate biodegradability (mineralization) in down the drain environmental compartments. An OECD 301B Ready Biodegradation Test was used to quantify ultimate biodegradability of microparticles made of PHBV foam, jojoba wax, beeswax, rice bran wax, stearyl stearate, blueberry seeds and walnut shells. PHBV polymer was ready biodegradable reaching 65.4 ± 4.1% evolved CO 2 in 5 d and 90.5 ± 3.1% evolved CO 2 in 80 d. PHBV foam microparticles (125-500 μm) were mineralized extensively with >66% CO 2 evolution in 28 d and >82% CO 2 evolution in 80 d. PHBV foam microparticles were mineralized at a similar rate and extent as microparticles made of jojoba wax, beeswax, rice bran wax, and stearyl stearate which reached 84.8  ± 4.8, 84.9  ± 2.2, 82.7  ± 4.7, and 86.4 ± 3.2% CO 2 evolution respectively in 80 d. Blueberry seeds and walnut shells mineralized more slowly only reaching 39.3  ± 6.9 and 5.1 ± 2.8% CO 2 evolution in 80 d respectively. Copyright © 2017 Elsevier Ltd. All rights reserved.

Lignins : natural polymers from oxidative coupling of 4-hydroxyphenyl-propanoids

Science.gov (United States)

John Ralph; Knut Lundquist; Gosta Brunow; Fachuang Lu; Hoon Kim; Paul F. Schatz; Jane M. Marita; Ronald D. Hatfield; Sally A. Ralph; Jorgen Holst Christensen; Wout Boerjan

2004-01-01

Lignins are complex natural polymers resulting from oxidative coupling of, primarily, 4-hydroxyphenylpropanoids. An understanding of their nature is evolving as a result of detailed structural studies, recently aided by the availability of lignin-biosynthetic-pathway mutants and transgenics. The currently accepted theory is that the lignin polymer is formed by...

Polymers targeting habitual diseases

Science.gov (United States)

The use of polymeric drug conjugates mainly for the treatment for cancer therapy has been addressed, but these polymers also find their way in treatment of various lifestyle disorders like diabetes, hypertension, cardiovascular diseases etc. The focus is being laid to develop biodegradable polymer ...

A new nano-TiO2 immobilized biodegradable polymer with self-cleaning properties.

Science.gov (United States)

Sökmen, Münevver; Tatlıdil, Ilknur; Breen, Chris; Clegg, Francis; Buruk, Celal Kurtuluş; Sivlim, Tuğba; Akkan, Senay

2011-03-15

This study concentrated on the direct immobilization of anatase nano titanium dioxide particles (TiO(2), 10nm particle size) into or onto a biodegradable polymer, polycaprolactone, by solvent-cast processes. The self-cleaning, namely photocatalytic properties of the produced materials were tested by photocatalytic removal of methylene blue as model compound and antimicrobial properties were investigated using Candida albicans as model microorganism. Produced TiO(2) immobilized polymer successfully removed methylene blue (MB, 1 × 10(-5)M) from aqueous solution without additional pH arrangement employing a UV-A light (365 nm) source. Almost 83.2% of dye was removed or decomposed by 5 wt% TiO(2) immobilized into PCL (0.08 g) and removal percentage reached to 94.2% with 5 wt% TiO(2) immobilized onto PCL after a 150 min exposure period. Although removal percentage decrease with increased ionic strength and usage of a visible light source, produced materials were still effective. TiO(2) immobilized onto PCL (5 wt%) was quite effective killing almost 54% of C. albicans (2 × 10(6)CFU/mL) after only 60 min exposure with a near visible light source. Control experiments employing PCL alone in the presence and absence of light were ineffective under the same condition. Copyright © 2011 Elsevier B.V. All rights reserved.

Radiation crosslinking of polymer materials

International Nuclear Information System (INIS)

Yoshii, Fumio

2004-01-01

It was found that some polyfunctional monomers (PFM) like triallyl isocyanurate (TAIC) and trimethallyl isocyanurate (TMAIC) when incorporated at low concentrations, are effective for promotion of crosslinking of biodegradable polymers such as polycaprolactone (PCL), poly(butylene succinate-co-adipate) (PBS) and poly(lactic acid) (PLA). PFM are kneaded with biodegradable polymers at molten condition before irradiation. Radiation crosslinking of PBS and PCL with 1% TAIC gave gel fractions of 80% at 20 kGy. This crosslinking is effective to improve deformation of biodegradable polymers at high temperature. The irradiated materials retained their biodegradability even after crosslinking when subjected to soil burial test. Irradiation at molten state (melting temperature, 340degC) led to crosslinking structures for polytetrafluoroethylene (PTFE). Crosslinked PTFE forms transparent films with high abrasion property and high radiation resistance. High-density polyethylene (HDPE) has a higher gel fraction in irradiation at molten state than irradiation at ordinary temperature. Crosslinked HDPE has been applied as knee joints in order to have high abrasion. Radiation crosslinked polycarbosilane (PCS) fiber gives high heat resistant silicon carbide (SiC) after firing. EB irradiation of PCS is effective to improve strength of product and to inhibit flow during carbonization. SiC, being resistant to high temperature will be applied in turbine and body of rockets. (author)

Quercetin as natural stabilizing agent for bio-polymer

Energy Technology Data Exchange (ETDEWEB)

Morici, Elisabetta [Dipartimento di Ingegneria Chimica, Gestionale, Informatica, Meccanica, Università di Palermo, 90128 Palermo (Italy); Arrigo, Rossella; Dintcheva, Nadka Tzankova [Dipartimento di Ingegneria Civile, Ambientale, Aerospaziale, dei Materiali, Università di Palermo, 90128 Palermo (Italy)

2014-05-15

The introduction of antioxidants in polymers is the main way to prevent or delay the degradation process. In particular natural antioxidants receive attention in the food industry also because of their presumed safety. In this work bio-polymers, i.e. a commercial starch-based polymer (Mater-Bi®) and a bio-polyester (PLA), and a bio-polyether (PEO) were additivated with quercetin, a natural flavonoid antioxidants, in order to formulate bio-based films for ecosustainable packaging and outdoor applications. The photo-oxidation behavior of unstabilized and quercetin stabilized films was analyzed and compared with the behavior of films additivated with a commercial synthetic light stabilizer. The quercetin is able to slow down the photo-degradation rate of all bio-polymeric films investigated in similar way to the synthetic stabilizer.

Quercetin as natural stabilizing agent for bio-polymer

Science.gov (United States)

Morici, Elisabetta; Arrigo, Rossella; Dintcheva, Nadka Tzankova

2014-05-01

The introduction of antioxidants in polymers is the main way to prevent or delay the degradation process. In particular natural antioxidants receive attention in the food industry also because of their presumed safety. In this work bio-polymers, i.e. a commercial starch-based polymer (Mater-Bi®) and a bio-polyester (PLA), and a bio-polyether (PEO) were additivated with quercetin, a natural flavonoid antioxidants, in order to formulate bio-based films for ecosustainable packaging and outdoor applications. The photo-oxidation behavior of unstabilized and quercetin stabilized films was analyzed and compared with the behavior of films additivated with a commercial synthetic light stabilizer. The quercetin is able to slow down the photo-degradation rate of all bio-polymeric films investigated in similar way to the synthetic stabilizer.

Quercetin as natural stabilizing agent for bio-polymer

International Nuclear Information System (INIS)

Morici, Elisabetta; Arrigo, Rossella; Dintcheva, Nadka Tzankova

2014-01-01

The introduction of antioxidants in polymers is the main way to prevent or delay the degradation process. In particular natural antioxidants receive attention in the food industry also because of their presumed safety. In this work bio-polymers, i.e. a commercial starch-based polymer (Mater-Bi®) and a bio-polyester (PLA), and a bio-polyether (PEO) were additivated with quercetin, a natural flavonoid antioxidants, in order to formulate bio-based films for ecosustainable packaging and outdoor applications. The photo-oxidation behavior of unstabilized and quercetin stabilized films was analyzed and compared with the behavior of films additivated with a commercial synthetic light stabilizer. The quercetin is able to slow down the photo-degradation rate of all bio-polymeric films investigated in similar way to the synthetic stabilizer

Biodegradable magnesium alloys for orthopaedic applications: A review on corrosion, biocompatibility and surface modifications

Energy Technology Data Exchange (ETDEWEB)

Agarwal, Sankalp [Centre for Research in Engineering and Surface Technology, FOCAS Institute, Dublin Institute of Technology (Ireland); School of Food Science and Environmental Health, Cathal Brugha Street, Dublin Institute of Technology (Ireland); Curtin, James [School of Food Science and Environmental Health, Cathal Brugha Street, Dublin Institute of Technology (Ireland); Duffy, Brendan [Centre for Research in Engineering and Surface Technology, FOCAS Institute, Dublin Institute of Technology (Ireland); Jaiswal, Swarna, E-mail: swarna.jaiswal@dit.ie [Centre for Research in Engineering and Surface Technology, FOCAS Institute, Dublin Institute of Technology (Ireland)

2016-11-01

Magnesium (Mg) and its alloys have been extensively explored as potential biodegradable implant materials for orthopaedic applications (e.g. Fracture fixation). However, the rapid corrosion of Mg based alloys in physiological conditions has delayed their introduction for therapeutic applications to date. The present review focuses on corrosion, biocompatibility and surface modifications of biodegradable Mg alloys for orthopaedic applications. Initially, the corrosion behaviour of Mg alloys and the effect of alloying elements on corrosion and biocompatibility is discussed. Furthermore, the influence of polymeric deposit coatings, namely sol-gel, synthetic aliphatic polyesters and natural polymers on corrosion and biological performance of Mg and its alloy for orthopaedic applications are presented. It was found that inclusion of alloying elements such as Al, Mn, Ca, Zn and rare earth elements provides improved corrosion resistance to Mg alloys. It has been also observed that sol-gel and synthetic aliphatic polyesters based coatings exhibit improved corrosion resistance as compared to natural polymers, which has higher biocompatibility due to their biomimetic nature. It is concluded that, surface modification is a promising approach to improve the performance of Mg-based biomaterials for orthopaedic applications. - Highlights: • The Mg based alloys are promising candidates for orthopaedic applications. • The rapid corrosion of Mg can affect human cells, and causes infection and implant failure. • The various physiological factors and Mg alloying elements affect the corrosion and mechanical properties of implants. • The polymeric deposit coatings enhance the corrosion resistance and biocompatibility.

Biodegradable magnesium alloys for orthopaedic applications: A review on corrosion, biocompatibility and surface modifications

International Nuclear Information System (INIS)

Agarwal, Sankalp; Curtin, James; Duffy, Brendan; Jaiswal, Swarna

2016-01-01

Magnesium (Mg) and its alloys have been extensively explored as potential biodegradable implant materials for orthopaedic applications (e.g. Fracture fixation). However, the rapid corrosion of Mg based alloys in physiological conditions has delayed their introduction for therapeutic applications to date. The present review focuses on corrosion, biocompatibility and surface modifications of biodegradable Mg alloys for orthopaedic applications. Initially, the corrosion behaviour of Mg alloys and the effect of alloying elements on corrosion and biocompatibility is discussed. Furthermore, the influence of polymeric deposit coatings, namely sol-gel, synthetic aliphatic polyesters and natural polymers on corrosion and biological performance of Mg and its alloy for orthopaedic applications are presented. It was found that inclusion of alloying elements such as Al, Mn, Ca, Zn and rare earth elements provides improved corrosion resistance to Mg alloys. It has been also observed that sol-gel and synthetic aliphatic polyesters based coatings exhibit improved corrosion resistance as compared to natural polymers, which has higher biocompatibility due to their biomimetic nature. It is concluded that, surface modification is a promising approach to improve the performance of Mg-based biomaterials for orthopaedic applications. - Highlights: • The Mg based alloys are promising candidates for orthopaedic applications. • The rapid corrosion of Mg can affect human cells, and causes infection and implant failure. • The various physiological factors and Mg alloying elements affect the corrosion and mechanical properties of implants. • The polymeric deposit coatings enhance the corrosion resistance and biocompatibility.

Gold nanoparticles applications in natural polymer modified for UV protection; Aplicacao de nanoparticulas de ouro em polimero natural modificado para protecao ultravioleta

Energy Technology Data Exchange (ETDEWEB)

Silva, Iris O. da; Ladchumananandasivam, Rasiah; Nascimento, Jose H. O. do; Silva, Francisco C. da; Sa, Christiane S. de A., E-mail: iris.oliveira@gmail.com.br [Universidade Federal do Rio Grande do Norte (PPGEM/UFRN), Natal, RN (Brazil)

2015-07-01

The protein-based polymers such as milk, such as polylactic acid (PLA) and soya can be cited as examples of substrates used in various fields of engineering, mainly due to its character of biodegradability, generating low environmental impact when compared to chemical polymers to petroleum-based, which take years to decompose in nature. Among these, soy fiber has great application potential because it is a manufactured material base of a residue obtained from the existing folder in the soybean seeds after oil extraction, using resins and chemicals for structural modification. In this work, soy mesh was used to develop a material with ultraviolet protection properties, through the use of nanotechnology. Thus, to connect the gold nanoparticles (NPAu), the fabric had a surface charge modified with the use of chitosan, using 20% of the weight of the material, followed by nanomaterials exhaust process. The NPAu were synthesized via chemical synthesis with sodium nitrate as reducing and stabilizing agent. The analysis of the solution samples were evaluated by absorbance spectroscopy and solid materials through diffuse reflectance spectroscopy and XRD X-ray diffraction. The size of NPAu was evaluated in equipment Zetasizer nanoseries / nanoZ, finding nanoparticles with an average size of 34.59 nm, and also underlined plasmon resonance phenomenon, with peaks between 530 nm and red coloration, and good results from the soundness washes, compared to conventional dyeing. It was found that soy polymer treated with NPAu presented an excellent property with ultraviolet protection factor (UPF) of +50, considered excellent, proving its potential application in the biomedical field. (author)

Microbial biodegradable potato starch based low density polyethylene

African Journals Online (AJOL)

USER

2010-06-28

Jun 28, 2010 ... Key words: Low density polyethylene, fungi, biodegradable polymer, Pseudomonas aeruginosa. ... particle such as CO2 or water by microorganism's activities. ... package and production of bags, composites and agricultural.

Biodegradability standards for carrier bags and plastic films in aquatic environments: a critical review.

Science.gov (United States)

Harrison, Jesse P; Boardman, Carl; O'Callaghan, Kenneth; Delort, Anne-Marie; Song, Jim

2018-05-01

Plastic litter is encountered in aquatic ecosystems across the globe, including polar environments and the deep sea. To mitigate the adverse societal and ecological impacts of this waste, there has been debate on whether 'biodegradable' materials should be granted exemptions from plastic bag bans and levies. However, great care must be exercised when attempting to define this term, due to the broad and complex range of physical and chemical conditions encountered within natural ecosystems. Here, we review existing international industry standards and regional test methods for evaluating the biodegradability of plastics within aquatic environments (wastewater, unmanaged freshwater and marine habitats). We argue that current standards and test methods are insufficient in their ability to realistically predict the biodegradability of carrier bags in these environments, due to several shortcomings in experimental procedures and a paucity of information in the scientific literature. Moreover, existing biodegradability standards and test methods for aquatic environments do not involve toxicity testing or account for the potentially adverse ecological impacts of carrier bags, plastic additives, polymer degradation products or small (microscopic) plastic particles that can arise via fragmentation. Successfully addressing these knowledge gaps is a key requirement for developing new biodegradability standard(s) for lightweight carrier bags.

Cost-effectiveness analysis of biodegradable polymer versus durable polymer drug-eluting stents incorporating real-world evidence.

Science.gov (United States)

Teng, Monica; Zhao, Ying Jiao; Khoo, Ai Leng; Ananthakrishna, Rajiv; Yeo, Tiong Cheng; Lim, Boon Peng; Chan, Mark Y; Loh, Joshua P

2018-06-05

Compared with second-generation durable polymer drug-eluting stents (DP-DES), the cost-effectiveness of biodegradable polymer drug-eluting stents (BP-DES) remains unclear in the real-world setting. We assessed the cost-effectiveness of BP-DES in patients with coronary artery disease undergoing percutaneous coronary intervention (PCI). We developed a decision-analytic model to compare the cost-effectiveness of BP-DES to DP-DES over one year and five years from healthcare payer perspective. Relative treatment effects during the first year post-PCI were obtained from a real-world population analysis while clinical event risks in the subsequent four years were derived from a meta-analysis of published studies. At one year, based on the clinical data analysis of 497 propensity-score matched pairs of patients, BP-DES were associated with an incremental cost-effectiveness ratio (ICER) of USD20,503 per quality-adjusted life-year (QALY) gained. At five years, BP-DES yielded an ICER of USD4,062 per QALY gained. At the willingness-to-pay threshold of USD50,400 (one gross domestic product per capita in Singapore in 2015), BP-DES were cost-effective. Sensitivity analysis showed that the cost of stents had a significant impact on the cost-effectiveness of BP-DES. Threshold analysis demonstrated that if the cost difference between BP-DES and DP-DES exceeded USD493, BP-DES would not be cost-effective in patients with one-year of follow-up. BP-DES were cost-effective compared with DP-DES in patients with coronary artery disease at one year and five years after PCI. It is worth noting that the cost of stents had a significant impact on the findings. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Solvent-free formation of hydroxyapatite coated biodegradable particles via nanoparticle-stabilized emulsion route

International Nuclear Information System (INIS)

Okada, Masahiro; Fujii, Syuji; Nishimura, Taiki; Nakamura, Yoshinobu; Takeda, Shoji; Furuzono, Tsutomu

2012-01-01

Highlights: ► Hydroxyapatite (HAp) nanoparticles stabilized polymer melt-in-water emulsions without any molecular surfactants. ► Interaction between polymer and HAp played a crucial role. ► HAp-coated polymer particles were obtained from the emulsions without any organic solvents. - Abstract: Hydroxyapatite (HAp) nanoparticle-coated biodegradable polymer particles were fabricated from a nanoparticle-stabilized emulsion in the absence of any molecular surfactants or organic solvents. First, a polymer melt-in-water emulsion was prepared by mixing a water phase containing nanosized HAp particles as a particulate emulsifier and an oil phase consisting of poly(ε-caprolactone) (PCL) or poly(L-lactide-co-ε-caprolactone) (P(LLA-CL)) above its melting point. It was clarified that the interaction between ester/carboxyl groups of the polymers and the HAp nanoparticles at the polymer–water interface played a crucial role to prepare the nanoparticle-stabilized emulsion. The HAp nanoparticle-coated biodegradable polymer particle (a polymer solid-in-water emulsion) was fabricated by cooling the emulsion. The particle morphology and particle size were evaluated using scanning electron microscope.

Biodegradable Materials and Metallic Implants-A Review.

Science.gov (United States)

Prakasam, Mythili; Locs, Janis; Salma-Ancane, Kristine; Loca, Dagnija; Largeteau, Alain; Berzina-Cimdina, Liga

2017-09-26

Recent progress made in biomaterials and their clinical applications is well known. In the last five decades, great advances have been made in the field of biomaterials, including ceramics, glasses, polymers, composites, glass-ceramics and metal alloys. A variety of bioimplants are currently used in either one of the aforesaid forms. Some of these materials are designed to degrade or to be resorbed inside the body rather than removing the implant after its function is served. Many properties such as mechanical properties, non-toxicity, surface modification, degradation rate, biocompatibility, and corrosion rate and scaffold design are taken into consideration. The current review focuses on state-of-the-art biodegradable bioceramics, polymers, metal alloys and a few implants that employ bioresorbable/biodegradable materials. The essential functions, properties and their critical factors are discussed in detail, in addition to their challenges to be overcome.

A REVIEW ON BIODEGRADABLE STARCH BASED FILM

Directory of Open Access Journals (Sweden)

Hooman Molavi

2015-04-01

Full Text Available In recent years, biodegradable edible films have become very important in research related to food, due to their compatibility with the environment and their use in the food packaging industry. Various sources can be used in the production of biopolymers as biodegradable films that include polysaccharides, proteins and lipids. Among the various polysaccharides, starch due to its low price and its abundance in nature is of significant importance. Several factors affect the properties of starch films; such as the source which starch is obtained from, as well as the ratio of constituents of the starch. Starch films have advantages such as low thickness, flexibility and transparency though; there are some downsides to mention, such as the poor mechanical properties and water vapor permeability. Thus, using starch alone to produce the film will led to restrictions on its use. To improve the mechanical properties of starch films and also increases resistance against humidity, several methods can be used; including the starch modifying techniques such as cross linking of starch and combining starch with other natural polymers. Other methods such as the use of lipid in formulations of films to increase the resistance to moisture are possible, but lipids are susceptible to oxidation. Therefore, new approaches are based on the integration of different biopolymers in food packaging.

A life cycle framework to support materials selection for Ecodesign: A case study on biodegradable polymers

International Nuclear Information System (INIS)

Ribeiro, I.; Peças, P.; Henriques, E.

2013-01-01

Highlights: • Life cycle framework to support material selection in Ecodesign. • Early design stage estimates and sensitivity analyses based on process-based models. • Sensitivity analysis to product geometry, industrial context and EoL scenarios. • Cost and environmental performance comparison – BDP vs. fossil based polymers. • Best alternatives mapping integrating cost and environmental performances. - Abstract: Nowadays society compels designers to develop more sustainable products. Ecodesign directs product design towards the goal of reducing environmental impacts. Within Ecodesign, materials selection plays a major role on product cost and environmental performance throughout its life cycle. This paper proposes a comprehensive life cycle framework to support Ecodesign in material selection. Dealing with new materials and technologies in early design stages, process-based models are used to represent the whole life cycle and supply integrated data to assess material alternatives, considering cost and environmental dimensions. An integrated analysis is then proposed to support decision making by mapping the best alternative materials according to the importance given to upstream and downstream life phases and to the environmental impacts. The proposed framework is applied to compare the life cycle performance of injection moulded samples made of four commercial biodegradable polymers with different contents of Thermo Plasticized Starch and PolyLactic Acid and a common fossil based polymer, Polypropylene. Instead of labelling materials just as “green”, the need to fully capture all impacts in the whole life cycle was shown. The fossil based polymer is the best economic alternative, but polymers with higher content of Thermo Plasticized Starch have a better environmental performance. However, parts geometry and EoL scenarios play a major role on the life cycle performance of candidate materials. The selection decision is then supported by mapping

Biodegradable polymeric foam with food waste; Shokumotsu zansa wo mochiita seibunkai kobunshi hahhotai

Energy Technology Data Exchange (ETDEWEB)

Mishima, Kenji; Matsuyama, Kiyoshi; Yamauchi, Satoru; Takarabe, Shin' ichi

1999-09-01

A huge amount of food waste such as tea and beer dregs becomes a serious problem because of the lack of industrial waste space in Japan. On the other hand, the new polymeric foam is expected to be developed since the dangerous pollution of endorphin disrupters from industrial polymer foam is pointed out. In this work, we try to develop the biodegradable polymeric foam using the tea and beer dregs as secondary resources. And we examined the degradability of biodegradable polymer in the hydrothermal water for fundamental knowledge of polymeric foam production. We used an extruder equipped with a high pressure device to make the polymeric foam. And we examined the effect of the component ratio on the foam properties, foaming rate, strength, shrinkage rate, water-resistant. As a result, it was found that the amount of polymer is effective of quality of form and the biodegradability can be controlled by the amount of water and temperature. (author)

Degradation Studies of b-Cyclodextrin Polyurethane Polymers using ...

African Journals Online (AJOL)

NJD

A biodegradable polymer undergoes significant chemical and .... After filter- ing, the isolated white polymer was washed with copious amounts of acetone (3 × 100 mL) to ... polymers to have contact with air, moisture and microorganisms.

Influence of biodegradable polymer coatings on corrosion, cytocompatibility and cell functionality of Mg-2.0Zn-0.98Mn magnesium alloy.

Science.gov (United States)

Witecka, Agnieszka; Yamamoto, Akiko; Idaszek, Joanna; Chlanda, Adrian; Święszkowski, Wojciech

2016-08-01

Four kinds of biodegradable polymers were employed to prepare bioresorbable coatings on Mg-2.0Zn-0.98Mn (ZM21) alloy to understand the relationship between polymer characteristics, protective effects on substrate corrosion, cytocompatibility and cell functionality. Poly-l-lactide (PLLA), poly(3-hydroxybutyrate) (PHB), poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) or poly(lactic-co-glycolic) acid (PLGA) was spin-coated on ZM21, obtaining a smooth, non-porous coating less than 0.5μm in thickness. Polymer coating characterization, a degradation study, and biocompatibility evaluations were performed. After 4 w of immersion into cell culture medium, degradation of PLGA and PLLA coatings were confirmed by ATR-FTIR observation. The coatings of PLLA, PHB and PHBV, which have lower water permeability and slower degradation than PLGA, provide better suppression of initial ZM21 degradation and faster promotion of human osteosarcoma cell growth and differentiation. Copyright © 2016 Elsevier B.V. All rights reserved.

Ampicillin-Ester Bonded Branched Polymers: Characterization, Cyto-, Genotoxicity and Controlled Drug-Release Behaviour

Directory of Open Access Journals (Sweden)

Ewa Oledzka

2014-06-01

Full Text Available The development and characterization of novel macromolecular conjugates of ampicillin using branched biodegradable polymers has been described in this study. The conjugates have been prepared coupling the β-lactam antibiotic with branched polymer matrices based on the natural oligopeptide core. The cyto- and genotoxicity of the synthesized polymers were evaluated with a bacterial luminescence test, two protozoan assays and Salmonella typhimurium TA1535. The presence of a newly formed covalent bond between the drug and the polymer matrices was confirmed by 1H-NMR and FTIR studies. A drug content (15.6 and 10.2 mole % in the macromolecular conjugates has been determined. The obtained macromolecular products have been subjected to further in vitro release studies. The total percentage of ampicillin released after 21 days of incubation was nearly 60% and 14% and this resulted from the different physicochemical properties of the polymeric matrices. This is the first report on the application of branched biodegradable polymeric matrices for the covalent conjugation of ampicillin. The obtained results showed that the synthesized macromolecular drug-conjugates might slowly release the active drug molecule and improve the pharmacokinetics of ampicillin.

Antibacterial Efficiency of Hydroxyapatite Biomaterials with Biodegradable Polylactic Acid and Polycaprolactone Polymers Saturated with Antibiotics / Bionoārdāmu Polimēru Saturošu Un Ar Antibiotiskajām Vielām Piesūcinātu Biomateriālu Antibakteriālās Efektivitātes Noteikšana

Directory of Open Access Journals (Sweden)

Kroiča Juta

2016-08-01

Full Text Available Infections continue to spread in all fields of medicine, and especially in the field of implant biomaterial surgery, and not only during the surgery, but also after surgery. Reducing the adhesion of bacteria could decrease the possibility of biomaterial-associated infections. Bacterial adhesion could be reduced by local antibiotic release from the biomaterial. In this in vitro study, hydroxyapatite biomaterials with antibiotics and biodegradable polymers were tested for their ability to reduce bacteria adhesion and biofilm development. This study examined the antibacterial efficiency of hydroxyapatite biomaterials with antibiotics and biodegradable polymers against Staphylococcus epidermidis and Pseudomonas aeruginosa. The study found that hydroxyapatite biomaterials with antibiotics and biodegradable polymers show longer antibacterial properties than hydroxyapatite biomaterials with antibiotics against both bacterial cultures. Therefore, the results of this study demonstrated that biomaterials that are coated with biodegradable polymers release antibiotics from biomaterial samples for a longer period of time and may be useful for reducing bacterial adhesion on orthopedic implants.

Development of Highly Efficient Grafting Technique and Synthesis of Natural Polymer-Based Graft Adsorbent

Energy Technology Data Exchange (ETDEWEB)

Ueki, Y; Seko, N; Tamada, M [Japan Atomic Energy Agency, Quantum Beam Science Directorate, Takasaki (Japan)

2012-09-15

In the framework of the CRP, Japan has focused on the development of fibrous adsorbents for removal of toxic metal ions and recovery of significant metal ions from industrial wastewater and streaming water. Graft polymerization was carried out by using gamma irradiation facility and electron beam accelerator. Emulsion grafting is a novel topic for synthesis of metal ion adsorbents which are prepared from fibrous trunk polymers such as polyethylene fibre and biodegradable nonwoven fabrics. The emulsion grafting, where monomer micelles are dispersed in water in the presence of surfactant, is a highly efficient and economic grafting technique as compared to general organic solvent system. The resultant cotton-based adsorbent has high adsorption efficiency and high adsorption capacity for Hg, besides, it is biodegradable. Polylactic acid can also be used as a trunk material for the grafting. (author)

Bamboo reinforced polymer composite - A comprehensive review

Science.gov (United States)

Roslan, S. A. H.; Rasid, Z. A.; Hassan, M. Z.

2018-04-01

Bamboo has greatly attention of researchers due to their advantages over synthetic polymers. It is entirely renewable, environmentally-friendly, non-toxic, cheap, non-abrasive and fully biodegradable. This review paper summarized an oveview of the bamboo, fiber extraction and mechanical behavior of bamboo reinforced composites. A number of studies proved that mechanical properties of bamboo fibers reinforced reinforced polymer composites are excellent and competent to be utilized in high-tech applications. The properties of the laminate are influenced by the fiber loading, fibre orientation, physical and interlaminar adhesion between fibre and matrix. In contrast, the presence of chemical constituents such as cellulose, lignin, hemicellulose and wax substances in natural fibres preventing them from firmly binding with polymer resin. Thus, led to poor mechanical properties for composites. Many attempt has been made in order to overcome this issue by using the chemical treatment.

A poly(glycerol sebacate) based photo/thermo dual curable biodegradable and biocompatible polymer for biomedical applications.

Science.gov (United States)

Wang, Min; Lei, Dong; Liu, Zenghe; Chen, Shuo; Sun, Lijie; Lv, Ziying; Huang, Peng; Jiang, Zhongxing; You, Zhengwei

2017-10-01

Due to its biomimetic mechanical properties to soft tissues, excellent biocompatibility and biodegradability, poly (glycerol sebacate) (PGS) has emerged as a representative bioelastomer and been widely used in biomedical engineering. However, the typical curing of PGS needs high temperature (>120 °C), high vacuum (>1 Torr), and long duration (>12 h), which limit its further applications. Accordingly, we designed, synthesized and characterized a photo/thermo dual curable polymer based on PGS. Treatment of PGS with 2-isocyanatoethyl methacrylate without additional reagents readily produced a methacrylated PGS (PGS-IM). Photo-curing of PGS-IM for 10 min at room temperature using salt leaching method efficiently produced porous scaffolds with a thickness up to 1 mm. PGS-IM was adapt to thermo-curing as well. The combination of photo and thermo curing provided a further way to modulate the properties of resultant porous scaffolds. Interestingly, photo-cured scaffolds exhibited hierarchical porous structures carrying extensive micropores with a diameter from several to hundreds micrometers. All the scaffolds showed good elasticity and biodegradability. In addition, PGS-IM exhibited good compatibility with L929 fibroblast cells. We expect this new PGS based biomaterial will have a wide range of biomedical applications.

Development of advanced natural polymer using radiation technology

International Nuclear Information System (INIS)

Kang, Phil Hyun; Nho, Young Chang; Jeon, Jun Pyo

2012-01-01

This project was performed to develop the environment-friendly and higher value-added materials using natural polymers derivatives from biotic-resources by radiation technology. To study for structural change of natural polymer by radiation, the effect of electron beam and Gamma ray into four kinds of plants such as Kenaf core, kenaf bast, ock and cornhusk was investigated. As results of analysis about structural change of natural polymer by radiation, efficiently separating process of Lignin was developed by improved decomposition of Lignin with increasing power of radiation. Environ-friendly separating process of Cellulose and Lignin using radiation and water-cook was developed without toxically chemical treatment. Papers were fabricated by cellulose and tensile strength of pulp fabricated by radiation was invested properties of pulp depending on power of radiation. High purity cellulose was fabricated by reduced chemical ratio between hemi-cellulose and Lignin with control of radiative power. Manufacturing process of natural paper highly containing cellulose content was developed using efficient separation of cellulose from ock tree, kenaf core and kenaf bast through radiation technique. Cellulose fiber was fabricated using separated cellulose by radiation through the drying and wetting spinning with methanol and water. Also nano-fiber with Lignin was made by electro-spinning with different ratio between PAN and Lignin. Effect of thermal treatment and carbonization of fabricated nano-fiber was invested. Carbon fiber with Lignin was applied to high value-added a secondary battery used as a cathode in half cell type. The secondary battery with carbon fiber with Lignin used as a cathode showed very efficient performance, which revealed capacity-preservation with 100% during 100 cycles. This project could significantly contribute to national competitiveness with radiation technology and Low-carbon and green-growth industrial technology, based on securement of

Radiation processing of natural polymer in Malaysia

International Nuclear Information System (INIS)

Khairul Zaman; Kamaruddin Hashim; Zulkafli Ghazali; Mohd Hilmi Mahmood; Dahlan Hj. Mohd; Jamaliah Sharif

2007-01-01

Research on radiation processing of natural polymer has been carried out by Nuclear Malaysia since 10 years ago. The progress of the research is at various stages. Radiation processing of sago hydrogel has been commercialized. Meanwhile ago film for packaging is at the pilot scale trial. Palm oil products are ready to be further developed for commercialization with any interested industrial partner. On the other hand, some new materials are being developed based on natural rubber such as liquid natural as compatibilizer, natural rubber thermoplastic nanoclay composites and natural rubber magnetic nano particles composites. (author)

Natural Fiber Filament Wound Composites: A Review

Directory of Open Access Journals (Sweden)

Mohamed Ansari Suriyati

2017-01-01

Full Text Available In recent development, natural fibers have attracted the interest of engineers, researchers, professionals and scientists all over the world as an alternative reinforcement for fiber reinforced polymer composites. This is due to its superior properties such as high specific strength, low weight, low cost, fairly good mechanical properties, non-abrasive, eco-friendly and bio-degradable characteristics. In this point of view, natural fiber-polymer composites (NFPCs are becoming increasingly utilized in a wide variety of applications because they represent an ecological and inexpensive alternative to conventional petroleum-derived materials. On the other hand, considerable amounts of organic waste and residue from the industrial and agricultural processes are still underutilized as low-value energy sources. This is a comprehensive review discussing about natural fiber reinforced composite produced by filament winding technique.

Polymer blends made of poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) and epoxidized natural rubber: Thermal and mechanical response

Science.gov (United States)

Salim, Yoga Sugama; Han, Chan Chin; Kammer, Hans-Werner; Kumar, Sudesh; Neon, Gan Seng

2015-08-01

The ever-increasing demand of biodegradable over conventional polymers places microbial polyhydroxyalkanoates (PHA) as an ideal choice of research material for specific applications. In this study, polymer blends made of poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) [P(3HB-co-3HHx) and epoxidized natural rubber (ENR) were prepared using solution casting technique. The influence of ENR on thermal, morphological and mechanical properties of P(3HB-co-3HHx) was investigated. There are two glass transition (Tg) temperatures observed using differential scanning calorimeter. This indicates that P(3HB-co-3HHx) and ENR are immiscible at macroscopic level. Although the Tg of P(3HB-co-3HHx) is seen to shift toward ENR in the least manner, infrared analysis suggests that the crystal structure of P(3HB-co-3HHx) retains its conformational structure. In terms of morphology, ENR exists as droplets in P(3HB-co-3HHx)-rich phase, e.g. at ENR weight fraction (wENR) of 0.3. In dynamic mechanical analysis, all blend compositions exhibit solid-like behavior, with storage moduli larger than loss moduli, across the frequency sweep at room temperature.

NATURAL POLYMERS: CELLULOSE, CHITIN, CHITOSAN, GELATIN, STARCH, CARRAGEENAN, XYLAN AND DEXTRAN

Directory of Open Access Journals (Sweden)

Fatma Zohra Benabid

2016-12-01

Full Text Available Biopolymers have been investigated for drug fields. They are widely being studied because of their non-toxic and biocompatible in nature. Biopolymers are used in industries as diverse as paper, plastics, food, textiles, pharmaceuticals, and cosmetics.This review covers different natural polymers, recent techniques applied in their processing and characterization. Advanced applications of natural polymers, including chitin, chitosan, alginate, etc., are discussed.

Efficient removal of malachite green dye using biodegradable graft copolymer derived from amylopectin and poly(acrylic acid).

Science.gov (United States)

Sarkar, Amit Kumar; Pal, Aniruddha; Ghorai, Soumitra; Mandre, N R; Pal, Sagar

2014-10-13

This article reports on the application of a high performance biodegradable adsorbent based on amylopectin and poly(acrylic acid) (AP-g-PAA) for removal of toxic malachite green dye (MG) from aqueous solution. The graft copolymer has been synthesized and characterized using various techniques including FTIR, GPC, SEM and XRD analyses. Biodegradation study suggests that the co-polymer is biodegradable in nature. The adsorbent shows excellent potential (Qmax, 352.11 mg g(-1); 99.05% of MG has been removed within 30 min) for removal of MG from aqueous solution. It has been observed that point to zero charge (pzc) of graft copolymer plays significant role in adsorption efficacy. The adsorption kinetics and isotherm follow pseudo-second order and Langmuir isotherm models, respectively. Thermodynamics parameters suggest that the process of dye uptake is spontaneous. Finally desorption study shows excellent regeneration efficiency of adsorbent. Copyright © 2014 Elsevier Ltd. All rights reserved.

Meta-Analysis of Randomized Clinical Trials Comparing Biodegradable Polymer Drug-Eluting Stent to Second-Generation Durable Polymer Drug-Eluting Stents.

Science.gov (United States)

El-Hayek, Georges; Bangalore, Sripal; Casso Dominguez, Abel; Devireddy, Chandan; Jaber, Wissam; Kumar, Gautam; Mavromatis, Kreton; Tamis-Holland, Jacqueline; Samady, Habib

2017-03-13

The authors sought to perform a meta-analysis of randomized clinical trials (RCTs) comparing the safety and efficacy of biodegradable polymer drug-eluting stents (BP-DES) to second-generation durable polymer drug-eluting stents (DP-DES). Prior meta-analyses have established the superiority of BP-DES over bare-metal stents and first-generation DP-DES; however, their advantage compared with second-generation DP-DES remains controversial. The authors searched PubMed and Scopus databases for RCTs comparing BP-DES to the second-generation DP-DES. Outcomes included target vessel revascularization (TVR) as efficacy outcome and cardiac death, myocardial infarction (MI), and definite or probable stent thrombosis (ST) as safety outcomes. In addition, we performed landmark analysis for endpoints beyond 1 year of follow-up and a subgroup analysis based on the stent characteristics. The authors included 16 RCTs comprising 19,886 patients in the meta-analysis. At the longest available follow-up (mean duration 26 months), we observed no significant differences in TVR (p = 0.62), cardiac death (p = 0.46), MI (p = 0.98), or ST (risk ratio: 0.83, 95% confidence interval: 0.64 to 1.09; p = 0.19). Our landmark analysis showed that BP-DES were not associated with a reduction in the risk of very late ST (risk ratio: 0.87, 95% confidence interval: 0.49 to 1.53; p = 0.62). Similar outcomes were seen regardless of the eluting drug (biolimus vs. sirolimus), the stent platform (stainless steel vs. alloy), the kinetics of polymer degradation or drug release (6 months), the strut thickness of the BP-DES (thin 100 μm), or the DAPT duration (≥6 months vs. ≥12 months). BP-DES have similar safety and efficacy profiles to second-generation DP-DES. Published by Elsevier Inc.

Drug delivery's quest for polymers: Where are the frontiers?

Science.gov (United States)

Merkle, Hans P

2015-11-01

Since the legendary 1964 article of Folkman and Long entitled "The use of silicone rubber as a carrier for prolonged drug therapy" the role of polymers in controlled drug delivery has come a long way. Today it is evident that polymers play a crucial if not the prime role in this field. The latest boost owes to the interest in drug delivery for the purpose of tissue engineering in regenerative medicine. The focus of this commentary is on a selection of general and personal observations that are characteristic for the current state of polymer therapeutics and carriers. It briefly highlights selected examples for the long march of synthetic polymer-drug conjugates from bench to bedside, comments on the ambivalence of selected polymers as inert excipients versus biological response modifiers, and on the yet unsolved dilemma of cationic polymers for the delivery of nucleic acid therapeutics. Further subjects are the complex design of multifunctional polymeric carriers including recent concepts towards functional supramolecular polymers, as well as observations on stimuli-sensitive polymers and the currently ongoing trend towards natural and naturally-derived biopolymers. The final topic is the discovery and early development of a novel type of biodegradable polyesters for parenteral use. Altogether, it is not the basic and applied research in polymer therapeutics and carriers, but the translational process that is the key hurdle to proceed towards an authoritative approval of new polymer therapeutics and carriers. Copyright © 2015 Elsevier B.V. All rights reserved.

Biodegradable Materials and Metallic Implants—A Review

Science.gov (United States)

Prakasam, Mythili; Locs, Janis; Salma-Ancane, Kristine; Loca, Dagnija; Largeteau, Alain; Berzina-Cimdina, Liga

2017-01-01

Recent progress made in biomaterials and their clinical applications is well known. In the last five decades, great advances have been made in the field of biomaterials, including ceramics, glasses, polymers, composites, glass-ceramics and metal alloys. A variety of bioimplants are currently used in either one of the aforesaid forms. Some of these materials are designed to degrade or to be resorbed inside the body rather than removing the implant after its function is served. Many properties such as mechanical properties, non-toxicity, surface modification, degradation rate, biocompatibility, and corrosion rate and scaffold design are taken into consideration. The current review focuses on state-of-the-art biodegradable bioceramics, polymers, metal alloys and a few implants that employ bioresorbable/biodegradable materials. The essential functions, properties and their critical factors are discussed in detail, in addition to their challenges to be overcome. PMID:28954399

Unprecedented access to functional biodegradable polymers and coatings

NARCIS (Netherlands)

Lee, Jung Seok; Wang, Rong; Chen, Wei; Meng, Fenghua; Cheng, Ru; Deng, Chao; Feijen, Jan; Zhong, Zhiyuan

2011-01-01

The ever-growing biomedical technology such as tissue engineering, regenerative medicine, and controlled drug release intimately relies on the development of advanced functional biomaterials. Here, we report on versatile and robust synthesis of novel vinyl sulfone (VS)-functionalized biodegradable

Radiation effects on biodegradable polyesters

International Nuclear Information System (INIS)

Hiroshi Mitomo; Darmawan Darwis; Fumio Yoshii; Keizo Makuuchi

1999-01-01

Poly(3-hydroxybutyrate) [P(3HB)] and its copolymer poly(3-hydroxybutyrate-co-3hydroxyvalerate) [P(3HB-co-3HV)] are microbial biodegradable polyesters produced by many types of bacteria. Poly(butylene succinate) (PBS) and poly(E-caprolactone) (PCL) are also biodegradable synthetic polyesters which have been commercialized. These thermoplastics are expected for wide usage in environmental protection and blocompatible applications. Radiation grafting of hydrophilic monomers onto many polymers, e.g., polyethylene and polypropylene has been studied mainly for biomedical applications. In the present study, radiation-induced graft polymerization of vinyl monomers onto PHB and P(3HB-co-3HV) was carried out and improvement of their properties was studied. Changes in the properties and biodegradability were compared with the degree of grafting. Radiation-induced crosslinking of PBS and PCL which relatively show thermal and irradiation stability was also carried out to improve their thermal stability or processability. Irradiation to PBS and PCL mainly resulted in crosslinking and characterization of these crosslinked polyesters was investigated

Biodegradable electroactive materials for tissue engineering applications

Science.gov (United States)

Guimard, Nathalie Kathryn

This dissertation focuses on the development of biomaterials that could be used to enhance the regeneration of severed peripheral nerves. These materials were designed to be electroactive, biodegradable, and biocompatible. To render the materials electroactive the author chose to incorporate conducting polymer (CP) units into the materials. Because CPs are inherently non-degradable, the key challenge was to create a CP-based material that was also biodegradable. Two strategies were explored to generate a biodegradable CP-based material. The first strategy centered around the incorporation of both electroactive and biodegradable subunits into a copolymer system. In the context of this approach, two bis(methoxyquaterthiophene)-co-adipic acid polyester (QAPE) analogues were successfully synthesized, one through polycondensation (giving undoped QAPE) and the second through oxidative polymerization (giving doped QAPE-2). QAPE was found to be electroactive by cyclic voltammetry, bioerodible, and cytocompatible with Schwann cells. QAPE was doped with ferric perchlorate, although only a low doping percentage was realized (˜8%). Oxidative polymerization of a bis(bithiophene) adipate permitted the direct synthesis of doped QAPE-2, which was found to have a higher doping level (˜24%). The second strategy pursued with the goal of generating an electroactive biodegradable material involved covalently immobilizing low molecular weight polythiophene chains onto the surface of crosslinked hyaluronic acid (HA) films. HA films are not only biodegradable and biocompatible, but they also provide mechanical integrity to bilayer systems. Dicyclocarbodiimide coupling of carboxylic acids to HA alcohol groups was used to functionalize HA films. The HA-polythiophene composite is still in the early stages of development. However, to date, thiophene has been successfully immobilized at the surface of HA films with a high degree of substitution. The author has also shown that thiophene

Injection Molding and Mechanical Properties of Bio-Based Polymer Nanocomposites

Directory of Open Access Journals (Sweden)

Maria Chiara Mistretta

2018-04-01

Full Text Available The use of biodegradable/bio-based polymers is of great importance in addressing several issues related to environmental protection, public health, and new, stricter legislation. Yet some applications require improved properties (such as barrier or mechanical properties, suggesting the use of nanosized fillers in order to obtain bio-based polymer nanocomposites. In this work, bionanocomposites based on two different biodegradable polymers (coming from the Bioflex and MaterBi families and two different nanosized fillers (organo-modified clay and hydrophobic-coated precipitated calcium carbonate were prepared and compared with traditional nanocomposites with high-density polyethylene (HDPE as matrix. In particular, the injection molding processability, as well as the mechanical and rheological properties of the so-obtained bionanocomposites were investigated. It was found that the processability of the two biodegradable polymers and the related nanocomposites can be compared to that of the HDPE-based systems and that, in general, the bio-based systems can be taken into account as suitable alternatives.

Phthalates biodegradation in the environment.

Science.gov (United States)

Liang, Da-Wei; Zhang, Tong; Fang, Herbert H P; He, Jianzhong

2008-08-01

Phthalates are synthesized in massive amounts to produce various plastics and have become widespread in environments following their release as a result of extensive usage and production. This has been of an environmental concern because phthalates are hepatotoxic, teratogenic, and carcinogenic by nature. Numerous studies indicated that phthalates can be degraded by bacteria and fungi under aerobic, anoxic, and anaerobic conditions. This paper gives a review on the biodegradation of phthalates and includes the following aspects: (1) the relationship between the chemical structure of phthalates and their biodegradability, (2) the biodegradation of phthalates by pure/mixed cultures, (3) the biodegradation of phthalates under various environments, and (4) the biodegradation pathways of phthalates.

Biodegradable aliphatic-aromatic copolyester/corn starch blend composite reinforced with coffee parchment husk

International Nuclear Information System (INIS)

Silva, Valquiria A.; Teixeira, Jaciele G.; Gomes, Michelle G.; Ortiz, Angel V.; Oliveira, Rene R.; Scapin, Marcos A.; Moura, Esperidiana A.B.; Colombo, Maria A.

2013-01-01

In recent years, studies have shown that the addition of natural fiber or proper filler is an effective strategy for achieving improved properties in biodegradable polymer materials. Moreover, is especially important if such fibers are residues of agro-industrial processes. In this work, a promising technique to develop biodegradable polymer matrix composite based on aliphatic-aromatic copolyester/corn starch blend (Evela®) and coffee parchment husk, which is residue from coffee processing is described. The biodegradable polymeric blend (Evela®) with 5 % (w/w) of ball-milled coffee parchment husk fiber powder, with size ≤250 μm, without any modification was prepared by melt-mixing processing, using a twin screw extruder machine and then pelletized. In a second step, the pelletized Evela®)/coffee parchment (Composite) was then dried at 70 ± 2 deg C for 24 h in a circulating air oven, fed into injection molding machine and test specimens were obtained. The Composite specimen samples were irradiated using an electron beam accelerator, at radiation dose of 20 and 40 kGy, at room temperature in presence of air. The irradiated and non-irradiated samples were characterized by means of scanning electron microscopy (SEM), X-Ray diffraction (XRD), tensile tests and sol-gel analysis and the correlation between their properties was discussed. In addition, coffee parchment husk fiber characterization by SEM, EDS, XRD and WDXRF have also been carried out with a view to evaluate its importance in determining the end-use properties of the composite. (author)

Biodegradable aliphatic-aromatic copolyester/corn starch blend composite reinforced with coffee parchment husk

Energy Technology Data Exchange (ETDEWEB)

Silva, Valquiria A.; Teixeira, Jaciele G.; Gomes, Michelle G.; Ortiz, Angel V.; Oliveira, Rene R.; Scapin, Marcos A.; Moura, Esperidiana A.B. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Colombo, Maria A., E-mail: valquiriaalves36@yahoo.com.br [Faculdade de Tecnologia da Zona Leste (FATEC), Sao Paulo, SP (Brazil)

2013-07-01

In recent years, studies have shown that the addition of natural fiber or proper filler is an effective strategy for achieving improved properties in biodegradable polymer materials. Moreover, is especially important if such fibers are residues of agro-industrial processes. In this work, a promising technique to develop biodegradable polymer matrix composite based on aliphatic-aromatic copolyester/corn starch blend (Evela®) and coffee parchment husk, which is residue from coffee processing is described. The biodegradable polymeric blend (Evela®) with 5 % (w/w) of ball-milled coffee parchment husk fiber powder, with size ≤250 μm, without any modification was prepared by melt-mixing processing, using a twin screw extruder machine and then pelletized. In a second step, the pelletized Evela®)/coffee parchment (Composite) was then dried at 70 ± 2 deg C for 24 h in a circulating air oven, fed into injection molding machine and test specimens were obtained. The Composite specimen samples were irradiated using an electron beam accelerator, at radiation dose of 20 and 40 kGy, at room temperature in presence of air. The irradiated and non-irradiated samples were characterized by means of scanning electron microscopy (SEM), X-Ray diffraction (XRD), tensile tests and sol-gel analysis and the correlation between their properties was discussed. In addition, coffee parchment husk fiber characterization by SEM, EDS, XRD and WDXRF have also been carried out with a view to evaluate its importance in determining the end-use properties of the composite. (author)

Interpenetrating Polymer Networks as Innovative Drug Delivery Systems

Directory of Open Access Journals (Sweden)

Alka Lohani

2014-01-01

Full Text Available Polymers have always been valuable excipients in conventional dosage forms, also have shown excellent performance into the parenteral arena, and are now capable of offering advanced and sophisticated functions such as controlled drug release and drug targeting. Advances in polymer science have led to the development of several novel drug delivery systems. Interpenetrating polymer networks (IPNs have shown superior performances over the conventional individual polymers and, consequently, the ranges of applications have grown rapidly for such class of materials. The advanced properties of IPNs like swelling capacity, stability, biocompatibility, nontoxicity and biodegradability have attracted considerable attention in pharmaceutical field especially in delivering bioactive molecules to the target site. In the past few years various research reports on the IPN based delivery systems showed that these carriers have emerged as a novel carrier in controlled drug delivery. The present review encompasses IPNs, their types, method of synthesis, factors which affects the morphology of IPNs, extensively studied IPN based drug delivery systems, and some natural polymers widely used for IPNs.

Biodegradable plastic bags on the seafloor: A future threat for seagrass meadows?

Science.gov (United States)

Balestri, Elena; Menicagli, Virginia; Vallerini, Flavia; Lardicci, Claudio

2017-12-15

Marine plastic litter is a global concern. Carrier bags manufactured from non-biodegradable polymers constitute a large component of this litter. Because of their adverse impact on marine life, non-biodegradable bags have recently been replaced by biodegradable ones. However, growing evidence shows that these latter are not readily degradable in marine sediments and can alter benthic assemblages. The potential impact of biodegradable bags on seagrasses inhabiting sandy bottoms, which are the most widespread and productive ecosystems of the coastal zones, has been ignored. Mesocosm experiments were conducted to assess the effect of a commercialized biodegradable bag on a common seagrass species of the Mediterranean, Cymodocea nodosa, both at the level of individual plant (clonal growth) and of plant community (plant-plant relationships), under three culture regimes (plant alone, in combination with a neighbour of the same species or of the co-existing seagrass Zostera noltei) simulating different natural conditions (bare substrate, monospecific meadows or mixed meadows). The bag behaviour in marine sediment and sediment physical/chemical variables were also examined. After six months of sediment exposure, the bag retained considerable mass (85% initial weight) and reduced sediment pore-water oxygen concentration and pH. In the presence of bag, C. nodosa root spread and vegetative recruitment increased compared to controls, both intra- and interspecific interactions shifted from neutral to competitive, and the growth form changed from guerrilla (loosely arranged group of widely spaced ramets) to phalanx form (compact structure of closed spaced ramets) but only with Z. noltei. These findings suggest that biodegradable bags altering sediment geochemistry could promote the spatial segregation of seagrass clones and influence species coexistence. Copyright © 2017 Elsevier B.V. All rights reserved.

Improved safety and reduction in stent thrombosis associated with biodegradable polymer-based biolimus-eluting stents versus durable polymer-based sirolimus-eluting stents in patients with coronary artery disease: final 5-year report of the LEADERS (Limus Eluted From A Durable Versus ERodable Stent Coating) randomized, noninferiority trial.

Science.gov (United States)

Serruys, Patrick W; Farooq, Vasim; Kalesan, Bindu; de Vries, Ton; Buszman, Pawel; Linke, Axel; Ischinger, Thomas; Klauss, Volker; Eberli, Franz; Wijns, William; Morice, Marie Claude; Di Mario, Carlo; Corti, Roberto; Antoni, Diethmar; Sohn, Hae Y; Eerdmans, Pedro; Rademaker-Havinga, Tessa; van Es, Gerrit-Anne; Meier, Bernhard; Jüni, Peter; Windecker, Stephan

2013-08-01

This study sought to report the final 5 years follow-up of the landmark LEADERS (Limus Eluted From A Durable Versus ERodable Stent Coating) trial. The LEADERS trial is the first randomized study to evaluate biodegradable polymer-based drug-eluting stents (DES) against durable polymer DES. The LEADERS trial was a 10-center, assessor-blind, noninferiority, "all-comers" trial (N = 1,707). All patients were centrally randomized to treatment with either biodegradable polymer biolimus-eluting stents (BES) (n = 857) or durable polymer sirolimus-eluting stents (SES) (n = 850). The primary endpoint was a composite of cardiac death, myocardial infarction (MI), or clinically indicated target vessel revascularization within 9 months. Secondary endpoints included extending the primary endpoint to 5 years and stent thrombosis (ST) (Academic Research Consortium definition). Analysis was by intention to treat. At 5 years, the BES was noninferior to SES for the primary endpoint (186 [22.3%] vs. 216 [26.1%], rate ratio [RR]: 0.83 [95% confidence interval (CI): 0.68 to 1.02], p for noninferiority 1 year) and associated composite clinical outcomes. (Limus Eluted From A Durable Versus ERodable Stent Coating [LEADERS] trial; NCT00389220). Copyright © 2013 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Drug release control in delivery system for biodegradable polymer drugs by γ-radiation

International Nuclear Information System (INIS)

Yoshioka, Sumie; Azo, Yukio; Kojima, Shigeo

1997-01-01

Characterizations of the drug release from microsphere and hydrogel preparation made from biodegradable polymers were investigated aiming at development of a drug delivery system which allows an optimum drug delivery and the identification of the factors which control its delivery. Poly-lactic acid microspheres containing 10% of progesterone were produced from poly DL-lactic acid and exposed to γ-ray at 5-1000 kGy. And its glass transition temperature (Tg) was determined by differential scanning calorimetry. The temperature was gradually lowered with an increase in the dose of radiation. Tg of the microsphere exposed at 1000 kGy was lower by 10degC compared with the untreated one, showing that Tg control is possible without changing the size distribution of microsphere. Then, the amount of progesterone released from microsphere was determined. The release rate of the drug linearly increased with a square root of radiation time. These results indicate that the control of drug release rate is possible through controling the microsphere's Tg by γ-ray radiation. (M.N.)

Polylactide-based renewable composites from natural products residues by encapsulated film bag: characterization and biodegradability.

Science.gov (United States)

Wu, Chin-San

2012-09-01

In the present study, the biodegradability, morphology, and mechanical properties of composite materials consisting of acrylic acid-grafted polylactide (PLA-g-AA) and natural products residues (corn starch, CS) were evaluated. Composites containing acrylic acid-grafted PLA (PLA-g-AA/CS) exhibited noticeably superior mechanical properties due to their greater compatibility with CS compared with PLA/CS. The feasibility of using PLA-g-AA/CS as a film bag material to facilitate the controlled release of an encapsulated phosphate-solubilizing bacterium (PSB) Burkholderia cepacia as a fertilizer use promoter was then evaluated. For purposes of comparison and accurate characterization, a PLA film bag was also assessed. The results showed that the bacterium completely degraded both the PLA and the PLA-g-AA/CS composite film bags, resulting in cell release. The PLA-g-AA/CS (20 wt%) film bags were more biodegradable than those made of PLA, and displayed a higher loss of molecular weight and intrinsic viscosity, indicating a strong connection between these characteristics and biodegradability. Copyright © 2012 Elsevier Ltd. All rights reserved.

Nanobarium Titanate As Supplement To Accelerate Plastic Waste Biodegradation By Indigenous Bacterial Consortia

Science.gov (United States)

Kapri, Anil; Zaidi, M. G. H.; Goel, Reeta

2009-06-01

Plastic waste biodegradation studies have seen several developmental phases from the discovery of potential microbial cultures, inclusion of photo-oxidizable additives into the polymer chain, to the creation of starch-embedded biodegradable plastics. The present study deals with the supplementation of nanobarium titanate (NBT) in the minimal broth in order to alter the growth-profiles of the Low-density polyethylene (LDPE) degrading consortia. The pro-bacterial influence of the nanoparticles could be seen by substantial changes such as shortening of the lag phase and elongation of the exponential as well as stationary growth phases, respectively, which eventually increase the biodegradation efficiency. In-vitro biodegradation studies revealed better dissolution of LDPE in the presence of NBT as compared to control. Significant shifting in λ-max values was observed in the treated samples through UV-Vis spectroscopy, while Fourier transform infrared spectroscopy (FTIR) and simultaneous thermogravimetric-differential thermogravimetry-differential thermal analysis (TG-DTG-DTA) further confirmed the breakage and formation of bonds in the polymer backbone. Therefore, this study suggests the implementation of NBT as nutritional additive for plastic waste management through bacterial growth acceleration.

Synthesis and flocculation properties of gum ghatti andpoly(acrylamide-co-acrylonitrile) based biodegradable hydrogels

CSIR Research Space (South Africa)

Mittal, H

2014-12-01

Full Text Available This article reports the development of biodegradable flocculants based on graft co-polymers of gum ghatti (Gg) and a mixture of acrylamide and acrylonitrile co-monomers (AAm-co-AN). The hydrogel polymer exhibited an excellent swelling capacity...

Biodegradable plastics from Sinorhizobium meliloti as plastics compatible with the environment and human health

Directory of Open Access Journals (Sweden)

Mehrdad Hashemi Beidokhti

2016-03-01

Full Text Available Introduction: Polyhydroxyalkanoates (PHAs are natural polyesters and biodegradable plastics that are stored as intracellular inclusion bodies by a great variety of bacteria. The aim of this study was to extract polyhydroxyalkanoate from native Sinorhizobium meliloti in Iran. Materials and methods: Sinorhizobium meliloti isolates were collected from roots of alfalfa plants and were identified by Gram staining, biochemical experiments and amplification of 1500 bp fragment of 16Sr DNA gene. PHA granules were detected by microscopic examination. PHA production was evaluated in nutrient deficient medium and its amount was determined by conversion of PHA into crotonic acid by sulphuric acid treatment. The effect of various temperatures, agitation rate and carbon source (sucrose, mannitol, and maltose were evaluated on dry cell weight and polyhydroxybutyrate (PHB production. Results: The maximum amount of polymer production (43.10% was seen in basal mineral medium at 29°C, pH~7 and 215 revolutions per minute (rpm. The results of this research showed that the S5 isolate was capable to produce maximum poly3- hydroxybutyrate. The produced polymer was analyzed for its purity by GC- mass (gas chromatography- mass spectroscopy and confirmed to be PHB compared with the standard polymer. Discussion and conclusion: Native strains of Sinorhizobium can be used in the production of biodegradable plastics and the results of present study showed that S. meliloti S5 was capable to produce maximum PHB at 29°C, agitation rate of 215 rpm, and pH~7. 

Development of biodegradable magnesium alloy stents with coating

Directory of Open Access Journals (Sweden)

Lorenza Petrini

2014-07-01

Full Text Available Biodegradable stents are attracting the attention of many researchers in biomedical and materials research fields since they can absolve their specific function for the expected period of time and then gradually disappear. This feature allows avoiding the risk of long-term complications such as restenosis or mechanical instability of the device when the vessel grows in size in pediatric patients. Up to now biodegradable stents made of polymers or magnesium alloys have been proposed. However, both the solutions have limitations. The polymers have low mechanical properties, which lead to devices that cannot withstand the natural contraction of the blood vessel: the restenosis appears just after the implant, and can be ascribed to the compliance of the stent. The magnesium alloys have much higher mechanical properties, but they dissolve too fast in the human body. In this work we present some results of an ongoing study aiming to the development of biodegradable stents made of a magnesium alloy that is coated with a polymer having a high corrosion resistance. The mechanical action on the blood vessel is given by the magnesium stent for the desired period, being the stent protected against fast corrosion by the coating. The coating will dissolve in a longer term, thus delaying the exposition of the magnesium stent to the corrosive environment. We dealt with the problem exploiting the potentialities of a combined approach of experimental and computational methods (both standard and ad-hoc developed for designing magnesium alloy, coating and scaffold geometry from different points of views. Our study required the following steps: i selection of a Mg alloy suitable for stent production, having sufficient strength and elongation capability; ii computational optimization of the stent geometry to minimize stress and strain after stent deployment, improve scaffolding ability and corrosion resistance; iii development of a numerical model for studying stent

(Biodegradable Ionomeric Polyurethanes Based on Xanthan: Synthesis, Properties, and Structure

Directory of Open Access Journals (Sweden)

T. V. Travinskaya

2017-01-01

Full Text Available New (biodegradable environmentally friendly film-forming ionomeric polyurethanes (IPU based on renewable biotechnological polysaccharide xanthan (Xa have been obtained. The influence of the component composition on the colloidal-chemical and physic-mechanical properties of IPU/Xa and based films, as well as the change of their properties under the influence of environmental factors, have been studied. The results of IR-, PMS-, DMA-, and X-ray scattering study indicate that incorporation of Xa into the polyurethane chain initiates the formation of a new polymer structure different from the structure of the pure IPU (matrix: an amorphous polymer-polymer microdomain has occurred as a result of the chemical interaction of Xa and IPU. It predetermines the degradation of the IPU/Xa films as a whole, unlike the mixed polymer systems, and plays a key role in the improvement of material performance. The results of acid, alkaline hydrolysis, and incubation into the soil indicate the increase of the intensity of degradation processes occurring in the IPU/Xa in comparison with the pure IPU. It has been shown that the introduction of Xa not only imparts the biodegradability property to polyurethane, but also improves the mechanical properties.

Polymer biocomposites with renewable sources

Directory of Open Access Journals (Sweden)

S. Kuciel

2010-07-01

Full Text Available Nowadays production of natural biodegradable polymer composites is an important research topic on the stage of renewable sourcesimplementation instead of petrochemical sources. In this work, possibilities of processing biocomposites on the base on different types of biopolymers – polylactide (PLA, thermoplastic starch (TPS, polyhydroxybutyrate (PHB, cellulose acetate (CA - filled with natural fibers such as wood, kenaf, horse hair and nettle are presented. Large variety of natural fibers and their developed surface which increases adhesion to matrix makes them an attractive filler material. The fibers serve as reinforcement by giving strength and stiffness to the structure while the polymer matrix holds the fibers in place so that suitable structural composites can be made. Main physic-mechanical properties of natural fibers and biopolymers are presented. Modulus of elasticity and tensile strength increased with rising content of natural fibers in composite. The results show that biocomposites based on starch or PHB filled with kenaf fibers has the best mechanical properties. Modulus of elasticity achieves 10-12 GPa and tensile strength 50 MPa. This property can be interesting for packaging especially for fresh food like fruits or vegetables and for technical products with short-time life cycles. In future prospects, biocomposites based on biopolymers with a long time of decomposition can be interesting alternative as a construction material in automotive sectors.

Rapid prototyping of biodegradable microneedle arrays by integrating CO2 laser processing and polymer molding

International Nuclear Information System (INIS)

Tu, K T; Chung, C K

2016-01-01

An integrated technology of CO 2 laser processing and polymer molding has been demonstrated for the rapid prototyping of biodegradable poly-lactic-co-glycolic acid (PLGA) microneedle arrays. Rapid and low-cost CO 2 laser processing was used for the fabrication of a high-aspect-ratio microneedle master mold instead of conventional time-consuming and expensive photolithography and etching processes. It is crucial to use flexible polydimethylsiloxane (PDMS) to detach PLGA. However, the direct CO 2 laser-ablated PDMS could generate poor surfaces with bulges, scorches, re-solidification and shrinkage. Here, we have combined the polymethyl methacrylate (PMMA) ablation and two-step PDMS casting process to form a PDMS female microneedle mold to eliminate the problem of direct ablation. A self-assembled monolayer polyethylene glycol was coated to prevent stiction between the two PDMS layers during the peeling-off step in the PDMS-to-PDMS replication. Then the PLGA microneedle array was successfully released by bending the second-cast PDMS mold with flexibility and hydrophobic property. The depth of the polymer microneedles can range from hundreds of micrometers to millimeters. It is linked to the PMMA pattern profile and can be adjusted by CO 2 laser power and scanning speed. The proposed integration process is maskless, simple and low-cost for rapid prototyping with a reusable mold. (paper)

Rapid prototyping of biodegradable microneedle arrays by integrating CO2 laser processing and polymer molding

Science.gov (United States)

Tu, K. T.; Chung, C. K.

2016-06-01

An integrated technology of CO2 laser processing and polymer molding has been demonstrated for the rapid prototyping of biodegradable poly-lactic-co-glycolic acid (PLGA) microneedle arrays. Rapid and low-cost CO2 laser processing was used for the fabrication of a high-aspect-ratio microneedle master mold instead of conventional time-consuming and expensive photolithography and etching processes. It is crucial to use flexible polydimethylsiloxane (PDMS) to detach PLGA. However, the direct CO2 laser-ablated PDMS could generate poor surfaces with bulges, scorches, re-solidification and shrinkage. Here, we have combined the polymethyl methacrylate (PMMA) ablation and two-step PDMS casting process to form a PDMS female microneedle mold to eliminate the problem of direct ablation. A self-assembled monolayer polyethylene glycol was coated to prevent stiction between the two PDMS layers during the peeling-off step in the PDMS-to-PDMS replication. Then the PLGA microneedle array was successfully released by bending the second-cast PDMS mold with flexibility and hydrophobic property. The depth of the polymer microneedles can range from hundreds of micrometers to millimeters. It is linked to the PMMA pattern profile and can be adjusted by CO2 laser power and scanning speed. The proposed integration process is maskless, simple and low-cost for rapid prototyping with a reusable mold.

In vitro evaluation and intra-articular administration of biodegradable microspheres containing naproxen sodium.

Science.gov (United States)

Bozdağ, S; Caliş, S; Kaş, H S; Ercan, M T; Peksoy, I; Hincal, A A

2001-01-01

The dispersion of non-steroidal antiinflammatory drugs (NSAIDs) into biodegradable polymeric matrices have been accepted as a good approach for obtaining a therapeutic effect in a predetermined period of time meanwhile minimizing the side effects of NSAIDs. In the present study, it was aimed to prepare Naproxen Sodium (NS), (a NSAID) loaded microsphere formulation using natural Bovine Serum Albumin (BSA) and synthetic biodegradable polymers such as poly(lactide-co-glycolic acid) (PLGA) (50:50 MW 34,000 and 88,000 Da) for intra-articular administration, and to study the retention of the drug at the site of injection in the knee joint. NS incorporated microspheres were evaluated in vitro for particle size (the mean particle size; for BSA microspheres, 10.0 +/- 0.3 microm, for PLGA microspheres, 9.0 +/- 0.2 and 5.0 +/- 0.1 microm for MW 34,000 and 88,000 Da, respectively), yield value, drug loading, surface morphology and drug release. For in vivo studies, monoarticular arthritis was induced in the left knee joints of rabbits by using ovalbumin and Freund's Complete Adjuvant as antigen and adjuvant. A certain time (4 days) is allowed for the formation of arthritis in the knee joints, then the NS loaded microspheres were injected directly into the articular cavity. At specific time points, gamma scintigrams were obtained to determine the residence time of the microspheres in knee joints, in order to determine the most suitable formulation. This study indicated that PLGA, a synthetic polymer, is more promising than the natural type BSA microspheres for an effective cure of mono-articular arthritis in rabbits.

Biodegradability of wheat gluten based bioplastics.

Science.gov (United States)

Domenek, Sandra; Feuilloley, Pierre; Gratraud, Jean; Morel, Marie-Hélène; Guilbert, Stéphane

2004-01-01

A large variety of wheat gluten based bioplastics, which were plasticized with glycerol, were subjected to biodegradation. The materials covered the total range available for the biochemical control parameter Fi, which expresses the percentage of aggregated proteins. This quantity can be related to the density of covalent crosslinks in the wheat gluten network, which are induced by technological treatments. The biodegradability tests were performed in liquid medium (modified Sturm test) and in farmland soil. All gluten materials were fully degraded after 36 days in aerobic fermentation and within 50 days in farmland soil. No significant differences were observed between the samples. The mineralization half-life time of 3.8 days in the modified Sturm test situated gluten materials among fast degrading polymers. The tests of microbial inhibition experiments revealed no toxic effects of the modified gluten or of its metabolites. Thus, the protein bulk of wheat gluten materials is non-toxic and fully biodegradable, whatever the technological process applied.

The biochemistry and molecular biology of xenobiotic polymer degradation by microorganisms.

Science.gov (United States)

Kawai, Fusako

2010-01-01

Research on microbial degradation of xenobiotic polymers has been underway for more than 40 years. It has exploited a new field not only in applied microbiology but also in environmental microbiology, and has greatly contributed to polymer science by initiating the design of biodegradable polymers. Owing to the development of analytical tools and technology, molecular biological and biochemical advances have made it possible to prospect for degrading microorganisms in the environment and to determine the mechanisms involved in biodegradation when xenobiotic polymers are introduced into the environment and are exposed to microbial attack. In this review, the molecular biological and biochemical aspects of the microbial degradation of xenobiotic polymers are summarized, and possible applications of potent microorganisms, enzymes, and genes in environmental biotechnology are suggested.

Report of the 2nd RCM on development of radiation-processed products of natural polymers for application in agriculture, healthcare, industry and environment. Working Material

Energy Technology Data Exchange (ETDEWEB)

NONE

2010-07-01

Radiation processing offers a clean and additive-free method for preparation of value-added novel materials based on renewable, non-toxic and biodegradable natural polymers and natural polymer waste. The results of research work showed that depending on the irradiation conditions, natural polysaccharides (alginate, chitin/chitosan, carrageeneans, carboxylmethylcellulose, etc.) could be either degraded or crosslinked by radiation. This paved the way for development of many successful applications; some of them commercialized, for use in agriculture, health care and environmental protection. The inputs for the formulation of this CRP and the key issues that need to be addressed were provided by the Consultant’s Meeting on “Radiation Processing of Natural Polymers for Development of Finished Products for Health Care, Agriculture and Environment” held in Kuala Lumpur, Malaysia from 26 – 30 March 2007. The main objective was defined as wide-spread promotion and general application of radiation processed natural materials, by coupling radiation technology and end-users to derive additional benefits from these value-added natural materials. The first RCM of the CRP was convened in Vienna on 21-25 April 2008. The participants presented and discussed the status of the field, the needs for further research, and various application possibilities. The work plan formulated during the meeting focused on harmonization of procedures for characterization of irradiated polymers, and protocols for investigation of the functional properties of degraded natural polymer products and their field testing. A network for collaboration was also proposed. The Meeting Report was published and is available for all Member States. The second RCM of this CRP was held in Reims, France, on 12–16 October 2009. The meeting was attended by 14 participants who reported their individual research results obtained since the first RCM, as well as their further plans. This meeting report contains

Report of the 2nd RCM on development of radiation-processed products of natural polymers for application in agriculture, healthcare, industry and environment. Working Material

International Nuclear Information System (INIS)

2010-01-01

Radiation processing offers a clean and additive-free method for preparation of value-added novel materials based on renewable, non-toxic and biodegradable natural polymers and natural polymer waste. The results of research work showed that depending on the irradiation conditions, natural polysaccharides (alginate, chitin/chitosan, carrageeneans, carboxylmethylcellulose, etc.) could be either degraded or crosslinked by radiation. This paved the way for development of many successful applications; some of them commercialized, for use in agriculture, health care and environmental protection. The inputs for the formulation of this CRP and the key issues that need to be addressed were provided by the Consultant’s Meeting on “Radiation Processing of Natural Polymers for Development of Finished Products for Health Care, Agriculture and Environment” held in Kuala Lumpur, Malaysia from 26 – 30 March 2007. The main objective was defined as wide-spread promotion and general application of radiation processed natural materials, by coupling radiation technology and end-users to derive additional benefits from these value-added natural materials. The first RCM of the CRP was convened in Vienna on 21-25 April 2008. The participants presented and discussed the status of the field, the needs for further research, and various application possibilities. The work plan formulated during the meeting focused on harmonization of procedures for characterization of irradiated polymers, and protocols for investigation of the functional properties of degraded natural polymer products and their field testing. A network for collaboration was also proposed. The Meeting Report was published and is available for all Member States. The second RCM of this CRP was held in Reims, France, on 12–16 October 2009. The meeting was attended by 14 participants who reported their individual research results obtained since the first RCM, as well as their further plans. This meeting report contains

Selective cell response on natural polymer bio-interfaces textured by femtosecond laser

Science.gov (United States)

Daskalova, A.; Trifonov, A.; Bliznakova, I.; Nathala, C.; Ajami, A.; Husinsky, W.; Declercq, H.; Buchvarov, I.

2018-02-01

This study reports on the evaluation of laser processed natural polymer-chitosan, which is under consideration as a biointerface used for temporary applications as skin and cartilage substitutes. It is employed for tissue engineering purposes, since it possesses a significant degree of biocompatibility and biodegradability. Chitosan-based thin films were processed by femtosecond laser radiation to enhance the surface properties of the material. Various geometry patterns were produced on polymer surfaces and employed to examine cellular adhesion and orientation. The topography of the modified zones was observed using scanning electron microscopy and confocal microscopy. Test of the material cytotoxicity was performed by evaluating the life/dead cell correlation. The obtained results showed that texturing with femtosecond laser pulses is appropriate method to initiate a predefined cellular response. Formation of surface modifications in the form of foams with an expansion of the material was created under laser irradiation with a number of applied laser pulses from N = 1-5. It is shown that irradiation with N > 5 results in disturbance of microfoam. Material characterization reveals a decrease in water contact angle values after laser irradiation of chitosan films. Consequently, changes in surface roughness of chitosan thin-film surface result in its functionalization. Cultivation of MC3T3 and ATMSC cells show cell orientational migration concerning different surface patterning. The influence of various pulse durations (varying from τ = 30-500 fs) over biofilms surface was examined regarding the evolution of surface morphology. The goal of this study was to define the optimal laser conditions (laser energy, number of applied pulses, and pulse duration) to alter surface wettability properties and porosity to improve material performance. The acquired set of results indicate the way to tune the surface properties to optimize cell-interface interaction.

Photoluminescence of Co: ZnNiO and Zr: ZnNiO nanocomposites capped with biodegradable polymer poly (2-ethyl-2-oxazoline)

Science.gov (United States)

John, Sam; George, James Baben; Joseph, Abraham

2018-05-01

The optical properties of the semiconducting nanomaterials has a wide variety of applications in the biological and industrial fields, which include the synthesis of UV laser, light emitting diodes, solar cells, gas sensors, piezoelectric transducers etc. Among the various types of optical properties, luminescence especially photoluminescence (PL) of metal oxides are more prominently studied. This is because PL spectrum is an effective way to investigate the electronic structure, optical and photochemical properties of semiconductor materials which deciphers information such as surface oxygen vacancies, defects, efficiency of charge carrier trapping, immigration, transfer etc. To overcome the drawbacks in luminescence studies of metal oxide nanomaterials, polymer technology has also been incorporated. The scientists found that the doping of some elements into the polymer capped ZnO nanocomposites enhanced the luminescence properties of the compound. In the current study, we are investigating the photoluminescence properties of ZnO nanocomposites capped with a biodegradable polymer poly (2-ethyl 2-oxazoline) and doped with the elements Cobalt and Zirconium. We obtained many strong fluorescence peaks in the visible and UV regions in the PL spectrum and UV absorption spectroscopy.

Health status of cows fed maize silage covered with oxo-biodegradable foil

Directory of Open Access Journals (Sweden)

Piotr SZTERK

2017-11-01

Full Text Available In agricultural practice, silage production uses pure, low density polyethylene foil. This foil, after use, becomes farm waste, having a negative impact on the environment. Instead of conventional foil, an environmentally safe biodegradable foil can be used, made from naturally occurring polymers or from synthetic multiparticulates, easily degradable by microorganisms. Silage covered with this type of foil should be safe for animal health. The purpose of the study was to determine whether oxo-biodegradable film could be used instead of conventional film in agricultural practice, to produce silage that is safe for the cows' health. Dairy cows were fed a partly mixed ratio (PMR, the component of which was silage made of whole maize plants, covered with oxo-biodegradable foil. The cow blood serum was marked for content of: glucose, total protein, cholesterol, triacylglycerols and enzyme activity: aspartic and alanine aminotransferase, γ-glutamyl transferase, alkaline phosphatase and amylase. The total protein concentration in the serum of cows analyzed at the end of the experiment was higher than the commonly accepted normal values. The content of glucose, cholesterol, triacylglycerols and the activity of aspartate and alanine aminotransferase, γ-glutamyl transferase, alkaline phosphatase and amylase was within reference limits. Feeding of silage from whole maize plants covered withoxo-biodegradable foil did not negatively affect the biochemical indicators of the cows' blood serum. The silage proved to be safe for the cows' health.

Biodegradable composites based on L-polylactide and jute fibres

DEFF Research Database (Denmark)

Plackett, David; Løgstrup Andersen, T.; Batsberg Pedersen, W.

2003-01-01

Biodegradable polymers can potentially be combined with plant fibres to produce biodegradable composite materials. In our research, a commercial L-polylactide was converted to film and then used in combination with jute fibre mats to generate composites by a film stacking technique. Composite...... in the 180-220 degreesC range were significantly higher than those of polylactide alone. Composite samples failed in a brittle fashion under tensile load and showed little sign of fibre pull-out. Examination of composite fracture surfaces using electron microscopy showed voids occurring between the jute...

Effects of ozonation and temperature on biodegradation of natural organic matter in biological granular activated carbon filters

NARCIS (Netherlands)

Van der Aa, L.T.J.; Rietveld, L.C.; Van Dijk, J.C.

2010-01-01

Four pilot (biological) granular activated carbon ((B)GAC) filters were operated to quantify the effects of ozonation and water temperature on the biodegradation of natural organic matter (NOM) in (B)GAC filters. Removal of dissolved organic carbon (DOC), assimilable organic carbon (AOC) and oxygen

Chitosan-gold-Lithium nanocomposites as solid polymer electrolyte.

Science.gov (United States)

Begum, S N Suraiya; Pandian, Ramanathaswamy; Aswal, Vinod K; Ramasamy, Radha Perumal

2014-08-01

Lithium micro batteries are emerging field of research. For environmental safety biodegradable films are preferred. Recently biodegradable polymers have gained wide application in the field of solid polymer electrolytes. To make biodegradable polymers films plasticizers are usually used. However, use of plasticizers has disadvantages such as inhomogenities in phases and mechanical instability that will affect the performance of Lithium micro batteries. We have in this research used gold nanoparticles that are environmentally friendly, instead of plasticizers. Gold nanoparticles were directly template upon chitosan membranes by reduction process so as to enhance the interactions of Lithium with the polymer. In this article, for the first time the characteristics of Chitosan-gold-Lithium nanocomposite films are investigated. The films were prepared using simple solution casting technique. We have used various characterization tools such as Small Angle Neutron Scattering (SANS), XRD, FTIR, Raman, FESEM, and AFM, Light scattering, Dielectric and electrical conductivity measurements. Our investigations show that incorporation of gold results in enhancement of conductivity in Lithium containing Chitosan films. Also it affects the dielectric characteristics of the films. We conclude through various characterization tools that the enhancement in the conductivity was due to the retardation of crystal growth of lithium salt in the presence of gold nanoparticles. A model is proposed regarding the formation of the new nanocomposite. The conductivity of these biodegradable films is comparable to those of the current inorganic Lithium micro batteries. This new chitosan-Au-Li nanocomposite has potential applications in the field of Lithium micro batteries.

Biodegradation of naphthalenesulphonate polymers: the potential of a combined application of fungi and bacteria.

Science.gov (United States)

Gullotto, Antonella; Lubello, Claudio; Mannucci, Alberto; Gori, Riccardo; Munz, Giulio; Briganti, Fabrizio

2015-01-01

The potential of several fungi and their synergy with bacterial biomasses were evaluated as a solution for the removal of 2-naphthalensulphonic acid polymers (2-NSAPs) from petrochemical wastewater, characterized by a chemical oxygen demand (COD) greater than 9000 mg/L. The ability of fungi to grow on 2-NSAP mixtures was preliminarily investigated using a solid medium, and then the action of the selected strains, both in suspended and immobilized form, was evaluated in terms of degradation, depolymerization, sorption and an increase in biodegradability of 2-NSAP. Among the 25 fungi evaluated two, in particular, Bjerkandera adusta and Pleurotus ostreatus, have been found to significantly depolymerize 2-NSAP yielding to the corresponding monomer (2-naphthalenesulphonic acid, 2-NSA), which has been further degraded by a bacterial consortia selected in a wastewater treatment plant (WWTP). The fungal treatment alone was able to reduce the COD value up to 44%, while activated sludge removed only 9% of the initial COD. In addition, the combined treatment (fungi and bacteria) allowed an increase in the COD removal up to 62%.

Natural Polymer-Cell Bioconstructs for Bone Tissue Engineering.

Science.gov (United States)

Titorencu, Irina; Albu, Madalina Georgiana; Nemecz, Miruna; Jinga, Victor V

2017-01-01

The major goal of bone tissue engineering is to develop bioconstructs which substitute the functionality of damaged natural bone structures as much as possible if critical-sized defects occur. Scaffolds that mimic the structure and composition of bone tissue and cells play a pivotal role in bone tissue engineering applications. First, composition, properties and in vivo synthesis of bone tissue are presented for the understanding of bone formation. Second, potential sources of osteoprogenitor cells have been investigated for their capacity to induce bone repair and regeneration. Third, taking into account that the main property to qualify one scaffold as a future bioconstruct for bone tissue engineering is the biocompatibility, the assessments which prove it are reviewed in this paper. Forth, various types of natural polymer- based scaffolds consisting in proteins, polysaccharides, minerals, growth factors etc, are discussed, and interaction between scaffolds and cells which proved bone tissue engineering concept are highlighted. Finally, the future perspectives of natural polymer-based scaffolds for bone tissue engineering are considered. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Development of biodegradable polymer based tamoxifen citrate loaded nanoparticles and effect of some manufacturing process parameters on them: a physicochemical and in-vitro evaluation

Directory of Open Access Journals (Sweden)

Basudev Sahana

2010-08-01

Full Text Available Basudev Sahana, Kousik Santra, Sumit Basu, Biswajit MukherjeeDepartment of Pharmaceutical Technology, Jadavpur University, Kolkata, IndiaAbstract: The aim of the present study was to develop nanoparticles of tamoxifen citrate, a non-steroidal antiestrogenic drug used for the treatment of breast cancer. Biodegradable poly (D, L- lactide-co-glycolide-85:15 (PLGA was used to develop nanoparticles of tamoxifen citrate by multiple emulsification (w/o/w and solvent evaporation technique. Drug-polymer ratio, polyvinyl alcohol concentrations, and homogenizing speeds were varied at different stages of preparation to optimize the desired size and release profile of drug. The characterization of particle morphology and shape was performed by field emission scanning electron microscope (FE-SEM and particle size distribution patterns were studied by direct light scattering method using zeta sizer. In vitro drug release study showed that release profile of tamoxifen from biodegradable nanoparticles varied due to the change in speed of centrifugation for separation. Drug loading efficiency varied from 18.60% to 71.98%. The FE-SEM study showed that biodegradable nanoparticles were smooth and spherical in shape. The stability studies of tamoxifen citrate in the experimental nanoparticles showed the structural integrity of tamoxifen citrate in PLGA nanoparticles up to 60°C in the tested temperatures. Nanoparticles containing tamoxifen citrate could be useful for the controlled delivery of the drug for a prolonged period.Keywords: biodegradable, nanoparticles, PLGA, stability, tamoxifen citrate

A novel use of bio-based natural fibers, polymers, and rubbers for composite materials

Science.gov (United States)

Modi, Sunny Jitendra

The composites, materials, and packaging industries are searching for alternative materials to attain environmental sustainability. Bio-plastics are highly desired and current microbially-derived bio-plastics, such as PHA (poly-(hydroxy alkanoate)), PHB (poly-(hydroxybutyrate)), and PHBV (poly-(beta-hydroxy butyrate-co-valerate)) could be engineered to have similar properties to conventional thermoplastics. Poly-(hydroxybutyrate) (PHB) is a bio-degradable aliphatic polyester that is produced by a wide range of microorganisms. Basic PHB has relatively high glass transition and melting temperatures. To improve flexibility for potential packaging applications, PHB is synthesized with various co-polymers such as Poly-(3-hydroxyvalerate) (HV) to decrease the glass and melting temperatures and, since there is improved melt stability at lower processing temperatures, broaden the processing window. However, previous work has shown that this polymer is too brittle, temperature-sensitive, and hydrophilic to meet packaging material physical requirements. Therefore, the proposed work focuses on addressing the needs for bio-derived and bio-degradable materials by creating a range of composite materials using natural fibers as reinforcement agents in bio-polymers and bio- plastic-rubber matrices. The new materials should possess properties lacking in PHBV and broaden the processing capabilities, elasticity, and improve the mechanical properties. The first approach was to create novel composites using poly-(beta-hydroxy butyrate-co-valerate) (PHBV) combined with fibers from invasive plants such as common reed (Phragmites australis), reed canary grass (Phalaris arundinacea), and water celery ( Vallisneria americana). The composites were manufactured using traditional processing techniques of extrusion compounding followed by injection molding of ASTM type I parts. The effects of each bio-fiber at 2, 5, and 10% loading on the mechanical, morphological, rheological, and thermal

Biodegradation of phenol-formaldehyde resins modified with commercial lignins

Energy Technology Data Exchange (ETDEWEB)

Bernard, M.; Nicolau, V. V. [Universidad Tecnologica Nacional (UTN), Cordoba (Argentina); Sponon, M.; Estenoz, D.A. [Instituto de Desarrollo Tecnologico para la Industria Quimica (INTEC/UNL/CONICET), Santa Fe (Argentina)

2014-07-01

Full text: In this work the biodegradation of partially-modified resols with 10% w/w of sodium lignosulfonate and 10 and 20 % w/w of Kraft lignin type is studied. The experimental work involved preliminary studies of biodegradation in Petri dish (clear zones), the degradation of resols by enzymatic attack of Pseudomonas aeruginosa under aerobic conditions for a period of 200 days and the characterization of the polymers before and after biodegradation by FT-IR and RMN spectroscopy, gas chromatography (GC) and scanning electron microscopy (SEM). The number of viable cells showed a significant increase during the process. However, the gravimetric analysis was not sufficient to check the biodegradation. The results indicated that endocellular enzymes could be involved. It was observed that the presence of low concentrations of toxic substances released during degradation of the material may have inhibitory effects. Resoles were synthesized in Centro S. A. San Francisco Cordoba, Argentina. (author)

Mechanical properties of a biodegradable bone regeneration scaffold

Science.gov (United States)

Porter, B. D.; Oldham, J. B.; He, S. L.; Zobitz, M. E.; Payne, R. G.; An, K. N.; Currier, B. L.; Mikos, A. G.; Yaszemski, M. J.

2000-01-01

Poly (Propylene Fumarate) (PPF), a novel, bulk erosion, biodegradable polymer, has been shown to have osteoconductive effects in vivo when used as a bone regeneration scaffold (Peter, S. J., Suggs, L. J., Yaszemski, M. J., Engel, P. S., and Mikos, A. J., 1999, J. Biomater. Sci. Polym. Ed., 10, pp. 363-373). The material properties of the polymer allow it to be injected into irregularly shaped voids in vivo and provide mechanical stability as well as function as a bone regeneration scaffold. We fabricated a series of biomaterial composites, comprised of varying quantities of PPF, NaCl and beta-tricalcium phosphate (beta-TCP), into the shape of right circular cylinders and tested the mechanical properties in four-point bending and compression. The mean modulus of elasticity in compression (Ec) was 1204.2 MPa (SD 32.2) and the mean modulus of elasticity in bending (Eb) was 1274.7 MPa (SD 125.7). All of the moduli were on the order of magnitude of trabecular bone. Changing the level of NaCl from 20 to 40 percent, by mass, did not decrease Ec and Eb significantly, but did decrease bending and compressive strength significantly. Increasing the beta-TCP from 0.25 g/g PPF to 0.5 g/g PPF increased all of the measured mechanical properties of PPF/NVP composites. These results indicate that this biodegradable polymer composite is an attractive candidate for use as a replacement scaffold for trabecular bone.

Natural and Synthetic Polymers as Inhibitors of Drug Efflux Pumps

Science.gov (United States)

2007-01-01

Inhibition of efflux pumps is an emerging approach in cancer therapy and drug delivery. Since it has been discovered that polymeric pharmaceutical excipients such as Tweens® or Pluronics® can inhibit efflux pumps, various other polymers have been investigated regarding their potential efflux pump inhibitory activity. Among them are polysaccharides, polyethylene glycols and derivatives, amphiphilic block copolymers, dendrimers and thiolated polymers. In the current review article, natural and synthetic polymers that are capable of inhibiting efflux pumps as well as their application in cancer therapy and drug delivery are discussed. PMID:17896100

[A comparative study of biodegradation kinetics of biopolymer systems based on poly(3-hydroxybutyrate)].

Science.gov (United States)

Boskhomdzhiev, A P; Banartsev, A P; Makhina, T K; Myshkina, V L; Ivanov, E A; Bagrov, D V; Filatova, E V; Iordanskiĭ, A L; Bonartseva, G A

2009-01-01

The aim of this study was to evaluate and to compare of long-term kinetics curves of biodegradation of poly(3-hydroxybutyrate) (PHB), its copolymer poly(3-hydroxybutyrate-co-3-hydroxyvalerate), and PHB/polylactic acid blend. The total weight loss and the change of average viscosity molecular weight were used as an index of biodegradation degree. The rate of biodegradation was analyzed in vitro in presence oflipase and in vivo when the films were implanted in animal tissues. The morphology of PHB films surface was studied by atomic force microscopy technique. It was shown that biodegradation of PHB is occurred by means of as polymer hydrolysis, and as its enzymatic biodegradation. The obtained data can be used for development of medical devices on the base of PHB.

Nanostructured bioactive polymers used in food-packaging.

Science.gov (United States)

Mateescu, Andreea L; Dimov, Tatiana V; Grumezescu, Alexandru M; Gestal, Monica C; Chifiriuc, Mariana C

2015-01-01

The development of effective packaging materials is crucial, because food microorganisms determine economic and public health issues. The current paper describes some of the most recent findings in regards of food preservation through novel packaging methods, using biodegradable polymers, efficient antimicrobial agents and nanocomposites with improved mechanical and oxidation stability, increased biodegradability and barrier effect comparatively with conventional polymeric matrices.

Biodegradable soy wound dressings with controlled release of antibiotics: Results from a guinea pig burn model.

Science.gov (United States)

Egozi, Dana; Baranes-Zeevi, Maya; Ullmann, Yehuda; Gilhar, Amos; Keren, Aviad; Matanes, Elias; Berdicevsky, Israela; Krivoy, Norberto; Zilberman, Meital

2015-11-01

There is growing interest in the development of biodegradable materials from renewable biopolymers, such as soy protein, for biomedical applications. Soy protein is a major fraction of natural soybean and has the advantages of being economically competitive, biodegradable and biocompatible. It presents good water resistance as well as storage stability. In the current study, homogenous antibiotic-loaded soy protein films were cast from aqueous solutions. The antibiotic drug gentamicin was incorporated into the films in order to inhibit bacterial growth, and thus prevent or combat infection, upon its controlled release to the surrounding tissue. The current in vivo study of the dressing material in contaminated deep second-degree burn wounds in guinea pigs (n=20) demonstrated its ability to accelerate epithelialization with 71% epithelial coverage compared to an unloaded format of the soy material (62%) and a significant improved epithelial coverage as compared to the conventional dressing material (55%). Our new platform of antibiotic-eluting wound dressings is advantageous over currently used popular dressing materials that provide controlled release of silver ions, due to its gentamicin release profile, which is safer. Another advantage of our novel concept is that it is based on a biodegradable natural polymer and therefore does not require bandage changes and offers a potentially valuable and economic approach for treating burn-related infections. Copyright © 2015 Elsevier Ltd and ISBI. All rights reserved.

Radiation Synthesis and Characterization of Natural and Natural-Synthetic Hybrid Super Absorbent Polymers for Agricultural Applications. Chapter 19

Energy Technology Data Exchange (ETDEWEB)

Şen, M.; Hayrabolulu, H.; Güven, O. [Hacettepe University Department of Chemistry, Beytepe, Ankara (Turkey)

2014-07-15

The experimental studies carried out in Hacettepe University, Laboratories of Radiation and Polymers Science (LRPS) in the past ten years, which focused mainly on the synthesis of synthetic and natural-synthetic super absorbent polymers in various irradiation conditions, are summarized in the first part of the presentation. Studies conducted on the following areas: (1) the controlled release of fertilizers and herbicides and the effect of the natural polymer type, (2) the neutralization degree of poly(acrylic acid), (3) the temperature and pressure on the swelling kinetics, and (4) the maximum water absorption capacity of the potential soil conditional hydrogels, were explained. The results were then compared with those obtained from commercial super absorbent polymers prepared through conventional techniques. In the third part of the presentation, basic and advanced techniques in the characterization of the network structure of super water absorbents were presented. (author)

Radiation Processing of Natural Polymers for Industrial Applications

International Nuclear Information System (INIS)

Hegazy, E.A.

2008-01-01

Radiation induced degradation technology is a new and promising application of ionizing radiation to develop viscose, pulp, paper, food preservation, pharmaceutical production, and natural bioactive agents industries. Controlling the degree of degradation, uniform molecular weight distribution, saving achieved in the chemicals (used in conventional methods) on a cost basis, and environmentally friendly process are the beneficial effects of using radiation technology in these industries. However, for some development countries such technology is not economic. Therefore, a great effort should be done to reduce the cost required for such technologies. One of the principle factors for reducing the cost is achieving the degradation at low irradiation doses. The addition of some additives such as potassium per-sulfate (KPS), ammonium per-sulfate (APS), or H 2 O 2 to natural polymers (carboxy-methylcellulose (CMC), chitosan, carrageenan and Na-alginate) during irradiation process accelerates their degradation. The highest degradation rate of polysaccharides obtained when APS was used. The end product of irradiated CMC, chitosan, carrageenan and Na-alginate may be used as food additive or benefited in agricultural purposes. On the other hand, radiation crosslinking of PAAm or PNIPAAm is affected by the presence of natural polymer like CMC-Na and carrageenan due to their degradability which could be controlled according to its concentration in the bulk medium and irradiation dose. Accordingly, the gel content, thermo-sensitivity (LCST) and swelling properties of PNIPAAm based natural polymers could be controlled. The swelling of the prepared copolymer hydrogels was investigated for its possible use in personal care articles particularly diapers or as carriers for drug delivery systems. The prepared crosslinked copolymers possessed high and fast swelling properties in simulated urine media and the swelling ratios of CMC-Na /PAAm gels in urine are acceptable for diaper

Biodegradability and mechanical properties of starch films from Andean crops.

Science.gov (United States)

Torres, F G; Troncoso, O P; Torres, C; Díaz, D A; Amaya, E

2011-05-01

Different Andean crops were used to obtain starches not previously reported in literature as raw material for the production of biodegradable polymers. The twelve starches obtained were used to prepare biodegradable films by casting. Water and glycerol were used as plasticizers. The mechanical properties of the starch based films were assessed by means of tensile tests. Compost tests and FTIR tests were carried out to assess biodegradability of films. The results show that the mechanical properties (UTS, Young's modulus and elongation at break) of starch based films strongly depend on the starch source used for their production. We found that all the starch films prepared biodegrade following a three stage process and that the weight loss rate of all the starch based films tested was higher than the weight loss rate of the cellulose film used as control. Copyright © 2011 Elsevier B.V. All rights reserved.

Preparation of poly(acrylamide-co-acrylic acid)-grafted gum and its flocculation and biodegradation studies.

Science.gov (United States)

Mittal, H; Mishra, Shivani B; Mishra, A K; Kaith, B S; Jindal, R; Kalia, S

2013-10-15

Biodegradation studies of Gum ghatti (Gg) and acrylamide-co-acrylic acid based flocculants [Gg-cl-poly(AAm-co-AA)] have been reported using the soil composting method. Gg-cl-poly(AAm-co-AA) was found to degrade 89.76% within 60 days. The progress of biodegradation at each stage was monitored through FT-IR and SEM. Polymer was synthesized under pressure using potassium persulphate-ascorbic acid as a redox initiator and N,N'-methylene-bis-acrylamide as a crosslinker. Synthesized polymer was found to show pH, temperature and ionic strength of the cations dependent swelling behavior. Gg-cl-poly(AAm-co-AA) was utilized for the selective absorption of saline from different petroleum fraction-saline emulsions. The flocculation efficiency of the polymer was studied as a function of polymer dose, temperature and pH of the solution. Gg-cl-poly(AAm-co-AA) showed maximum flocculation efficiency with 20 mol L(-1) polymer dose in acidic medium at 50 °C. Copyright © 2013. Published by Elsevier Ltd.

Investigation of evaporation and biodegradation of fuel spills in Antarctica: II-extent of natural attenuation at Casey Station.

Science.gov (United States)

Snape, Ian; Ferguson, Susan H; Harvey, Paul McA; Riddle, Martin J

2006-03-01

In many temperate regions, fuel and oil spills are sometimes managed simply by allowing natural degradation to occur, while monitoring soils and groundwater to ensure that there is no off-site migration or on-site impact. To critically assess whether this approach is suitable for coastal Antarctic sites, we investigated the extent of evaporation and biodegradation at three old fuel spills at Casey Station. Where the contaminants migrated across frozen ground, probably beneath snow, approximately half the fuel evaporated in the first few months prior to infiltration at the beginning of summer. Once in the ground, however, evaporation rates were negligible. In contrast, minor spills from fuel drums buried in an abandoned waste disposal site did not evaporate to the same extent. Biodegradation within all three spill sites is generally very minor. We conclude that natural attenuation is not a suitable management strategy for fuel-contaminated soils in Antarctic coastal regions.

ROLE OF NATURAL POLYMERS IN SUSTAINED RELEASE DRUG DELIVERY SYSTEM: APPLICATIONS AND RECENT APPROACHES

OpenAIRE

Prakash Pawan; Porwal Mayur; Saxena Ashwin

2011-01-01

In recent years there have been important developments in different dosage forms for existing and newly designed drugs and natural products, and semi-synthetic as well as synthetic excipients often need to be used for a variety of purposes. Gums and mucilages are widely used natural materials for conventional and novel dosage forms. These natural materials have advantages over synthetic ones since they are chemically inert, nontoxic, less expensive, biodegradable and widely available. They c...

Electrospun aniline-tetramer-co-polycaprolactone fibres for conductive, biodegradable scaffolds.

Science.gov (United States)

Guex, A G; Spicer, C D; Armgarth, A; Gelmi, A; Humphrey, E J; Terracciano, C M; Harding, S; Stevens, M M

2017-09-01

Conjugated polymers have been proposed as promising materials for scaffolds in tissue engineering applications. The restricted processability and biodegradability of conjugated polymers limit their use for biomedical applications however. Here we synthesised a block- co -polymer of aniline tetramer and PCL (AT-PCL), and processed it into fibrous non-woven scaffolds by electrospinning. We showed that fibronectin (Fn) adhesion was dependant on the AT-PCL oxidative state, with a reduced Fn unfolding length on doped membranes. Furthermore, we demonstrated the cytocompatibility and potential of these membranes to support the growth and osteogenic differentiation of MC3T3-E1 over 21 days.

GREENER PRODUCTION OF NOBLE METAL NANOSTRUCTURES AND NANOCOMPOSITES: RISK REDUCTION AND APPLICATIONS

Science.gov (United States)

The synthesis of nanometal/nano metal oxide/nanostructured polymer and their stabilization (through dispersant, biodegradable polymer) involves the use of natural renewable resources such plant material extract, biodegradable polymers, sugars, vitamins and finally efficient and s...

Durability of Starch Based Biodegradable Plastics Reinforced with Manila Hemp Fibers

Directory of Open Access Journals (Sweden)

Shinji Ochi

2011-02-01

Full Text Available The biodegradability of Manila hemp fiber reinforced biodegradable plastics was studied for 240 days in a natural soil and 30 days in a compost soil. After biodegradability tests, weights were measured and both tensile strength tests and microscopic observation were performed to evaluate the biodegradation behavior of the composites. The results indicate that the tensile strength of the composites displays a sharp decrease for up to five days, followed by a gradual decrease. The weight loss and the reduction in tensile strength of biodegradable composite materials in the compost soil are both significantly greater than those buried in natural soil. The biodegradability of these composites is enhanced along the lower portion because this area is more easily attacked by microorganisms.

Durability of Starch Based Biodegradable Plastics Reinforced with Manila Hemp Fibers.

Science.gov (United States)

Ochi, Shinji

2011-02-25

The biodegradability of Manila hemp fiber reinforced biodegradable plastics was studied for 240 days in a natural soil and 30 days in a compost soil. After biodegradability tests, weights were measured and both tensile strength tests and microscopic observation were performed to evaluate the biodegradation behavior of the composites. The results indicate that the tensile strength of the composites displays a sharp decrease for up to five days, followed by a gradual decrease. The weight loss and the reduction in tensile strength of biodegradable composite materials in the compost soil are both significantly greater than those buried in natural soil. The biodegradability of these composites is enhanced along the lower portion because this area is more easily attacked by microorganisms.

The catalytic microwave synthesis of biodegradable polyester polyols based on castor oil and l-lactide

Science.gov (United States)

Kojić, D.; Erceg, T.; Vukić, N.; Teofilović, V.; Ristić, I.; Budinski-Simendić, J.; Aleksić, V.

2017-01-01

Various strategies for achieving a functional poly(lactic acid) (PLA) have been developed such as ring-opening copolymerization with a functional monomer, the use of functional initiator and various post polymerization modifications. It is possible to obtain the star shaped polymer using natural oil with at least three OH groups as an initiator. It was estimated that despite of low-molecular mass of star-shaped PLA, the hydrophobic castor oil central core influenced the slow degradation rate in the case of injectable biomedical application. The star-shaped polymers with low-molecular-mass have a lower melt viscosity correlated with linear counterparts. In soft tissue reparation the polymer viscosity increases with fluid body contact and the solid implant can be formed. To ensure liquid state at injection temperature the low molar mass polymer is favorable. There is a particular size for each macromolecular chains at which chain entanglement occurs. In this work the influence of the l-lactide (LA) and the castor oil (CO) contents on the size of biodegradable branched polyester polyols was studied. The average molecular masses of synthesized polymers were estimated by GPC procedure. In sample formulations the [LA]/[CO] ratios were from to 113 to 533. Mn values for obtained polymers were from 5000 to 20000 Da. The molecular mass distribution for the resulting polymers was between 1.09 and 1.37.

Effects of ozonation and temperature on the biodegradation of natural organic matter in biological granular activated carbon filters

NARCIS (Netherlands)

Van der Aa, L.T.J.; Rietveld, L.C.; Van Dijk, J.C.

2011-01-01

Four pilot (biological) granular activated carbon ((B)GAC) filters were operated to quantify the effects of ozonation and water temperature on the biodegradation of natural organic matter (NOM) in (B)GAC filters. The removal of dissolved organic carbon (DOC), assimilable organic carbon (AOC) and

Development and Characterization of Polymer Eco-Composites Based on Natural Rubber Reinforced with Natural Fibers.

Science.gov (United States)

Stelescu, Maria-Daniela; Manaila, Elena; Craciun, Gabriela; Chirila, Corina

2017-07-11

Natural rubber composites filled with short natural fibers (flax and sawdust) were prepared by blending procedure and the elastomer cross-linking was carried out using benzoyl peroxide. The microbial degradation of composites was carried out by incubating with Aspergillus niger recognized for the ability to grow and degrade a broad range of substrates. The extent of biodegradation was evaluated by weight loss and cross-linking degree study of composites after 2 months incubation in pure shake culture conditions. Scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FT-IR) have proved to be precious and valuable instruments for morphological as well as structural characterization of the composites before and after incubation with Aspergillus niger .

Development and Characterization of Polymer Eco-Composites Based on Natural Rubber Reinforced with Natural Fibers

Directory of Open Access Journals (Sweden)

Maria-Daniela Stelescu

2017-07-01

Full Text Available Natural rubber composites filled with short natural fibers (flax and sawdust were prepared by blending procedure and the elastomer cross-linking was carried out using benzoyl peroxide. The microbial degradation of composites was carried out by incubating with Aspergillus niger recognized for the ability to grow and degrade a broad range of substrates. The extent of biodegradation was evaluated by weight loss and cross-linking degree study of composites after 2 months incubation in pure shake culture conditions. Scanning electron microscopy (SEM and Fourier transform infrared spectroscopy (FT-IR have proved to be precious and valuable instruments for morphological as well as structural characterization of the composites before and after incubation with Aspergillus niger.

Optical and mechanical properties of UV-weathered biodegradable PHBV/PBAT nanocomposite films containing halloysite nanotubes

Science.gov (United States)

Scarfato, P.; Avallone, E.; Acierno, D.; Russo, P.

2014-05-01

Recently, the increasing use of plastics, stringent environmental issues and the awareness of the progressive reduction of available petrochemical resources have ever more guided the research interest towards the investigation and development of innovative materials intrinsically biodegradable or derived from renewable sources, and generally known as bio-based polymers. Amongst the biobased and biodegradable polymers, many investigations were reported in literature about a family of polyesters known as poly(hydroxyalkanoate)s (PHAs), one of whose most prevalent is poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV). In this context, here we report the results of a photo-degradation study performed on biodegradable blown film samples based on a commercial grade PHBV/PBAT formulation. The films, subjected to photo-oxidative weathering in a climatic chamber under UV exposure, were systematically analysed in order to check the chemico-physical changes induced by the aging protocol, taking the as-produced films as the reference materials.

Biodegradable polymer sirolimus-eluting stents versus durable polymer everolimus-eluting stents for primary percutaneous coronary revascularisation of acute myocardial infarction.

Science.gov (United States)

Pilgrim, Thomas; Piccolo, Raffaele; Heg, Dik; Roffi, Marco; Tüller, David; Vuilliomenet, André; Muller, Olivier; Cook, Stéphane; Weilenmann, Daniel; Kaiser, Christoph; Jamshidi, Peiman; Khattab, Ahmed A; Taniwaki, Masanori; Rigamonti, Fabio; Nietlispach, Fabian; Blöchlinger, Stefan; Wenaweser, Peter; Jüni, Peter; Windecker, Stephan

2016-12-10

Our aim was to compare the safety and efficacy of a novel, ultrathin strut, biodegradable polymer sirolimus-eluting stent (BP-SES) with a thin strut, durable polymer everolimus-eluting stent (DP-EES) in a pre-specified subgroup of patients with acute ST-segment elevation myocardial infarction (STEMI) enrolled in the BIOSCIENCE trial. The BIOSCIENCE trial is an investigator-initiated, single-blind, multicentre, randomised non-inferiority trial (NCT01443104). Randomisation was stratified according to the presence or absence of STEMI. The primary endpoint, target lesion failure (TLF), is a composite of cardiac death, target vessel myocardial infarction, and clinically indicated target lesion revascularisation within 12 months. Between February 2012 and May 2013, 407 STEMI patients were randomly assigned to treatment with BP-SES or DP-EES. At one year, TLF occurred in seven (3.4%) patients treated with BP-SES and 17 (8.8%) patients treated with DP-EES (RR 0.38, 95% CI: 0.16-0.91, p=0.024). Rates of cardiac death were 1.5% in the BP-SES group and 4.7% in the DP-EES group (RR 0.31, 95% CI: 0.08-1.14, p=0.062); rates of target vessel myocardial infarction were 0.5% and 2.6% (RR 0.18, 95% CI: 0.02-1.57, p=0.082), respectively, and rates of clinically indicated target lesion revascularisation were 1.5% in the BP-SES group versus 2.1% in the DP-EES group (RR 0.69, 95% CI: 0.16-3.10, p=0.631). There was no difference in the risk of definite stent thrombosis. In this pre-specified subgroup analysis, BP-SES was associated with a lower rate of target lesion failure at one year compared to DP-EES in STEMI patients. These findings require confirmation in a dedicated STEMI trial.

Chitosan-Based Polymer Blends: Current Status and applications

International Nuclear Information System (INIS)

Hefian, E.A.E.; Nasef, M.M.

2014-01-01

This paper reviews the latest developments in chitosan-based blends and their potential applications in various fields. Various blends together with other derivatives, such as composites and graft copolymers, have been developed to overcome chitosans disadvantages, including poor mechanical properties and to improve its functionality towards specific applications. The progress made in blending chitosan with synthetic and natural polymers is presented. The versatility and unique characteristics, such as hydrophilicity, film-forming ability, biodegradability, biocompatibility, antibacterial activity and non-toxicity of chitosan has contributed to the successful development of various blends for medical, pharmaceutical, agricultural and environmental applications. (author)

Natural fiber-reinforced polymer composites

International Nuclear Information System (INIS)

Taj, S.; Khan, S.; Munawar, M.A.

2007-01-01

Natural fibers have been used to reinforce materials for over 3,000 years. More recently they have been employed in combination with plastics. Many types of natural fi fibers have been investigated for use in plastics including Flax, hemp, jute, straw, wood fiber, rice husks, wheat, barley, oats, rye, cane (sugar and bamboo), grass reeds, kenaf, ramie, oil palm empty fruit bunch, sisal, coir, water hyacinth, pennywort, kapok, paper-mulberry, raphia, banana fiber, pineapple leaf fiber and papyrus. Natural fibers have the advantage that they are renewable resources and have marketing appeal. The Asian markets have been using natural fibers for many years e.g., jute is a common reinforcement in India. Natural fibers are increasingly used in automotive and packaging materials. Pakistan is an agricultural country and it is the main stay of Pakistan's economy. Thousands of tons of different crops are produced but most of their wastes do not have any useful utilization. Agricultural wastes include wheat husk, rice husk, and their straw, hemp fiber and shells of various dry fruits. These agricultural wastes can be used to prepare fiber reinforced polymer composites for commercial use. This report examines the different types of fibers available and the current status of research. Many references to the latest work on properties, processing and application have been cited in this review. (author)

Editorial: Biodegradable Materials

Directory of Open Access Journals (Sweden)

Carl Schaschke

2014-11-01

Full Text Available This Special Issue “Biodegradable Materials” features research and review papers concerning recent advances on the development, synthesis, testing and characterisation of biomaterials. These biomaterials, derived from natural and renewable sources, offer a potential alternative to existing non-biodegradable materials with application to the food and biomedical industries amongst many others. In this Special Issue, the work is expanded to include the combined use of fillers that can enhance the properties of biomaterials prepared as films. The future application of these biomaterials could have an impact not only at the economic level, but also for the improvement of the environment.

Natural gums of plant origin as edible coatings for food industry applications.

Science.gov (United States)

Saha, Anuradha; Tyagi, Shvetambri; Gupta, Rajinder K; Tyagi, Yogesh K

2017-12-01

Natural plant-based gums and their derivatives are widely utilized in food industries, however, their applications as edible coatings to extend fresh fruits and vegetable shelf-life has been explored recently. These natural polymeric polysaccharides have many advantages as compared to synthetic polymers, because they are biodegradable, nontoxic, economical and easily available in the environment. Natural gums can also be semi synthetically modified to produce derivatives, which can easily compete with the synthetic preservatives available on the food market. In this review, the recent developments in the use of natural gums and their derivatives as edible coatings have been explored and discussed.

Revisiting the role of durable polymers in cardiovascular devices.

Science.gov (United States)

Mori, Hiroyoshi; Otsuka, Fumiyuki; Gupta, Anuj; Jinnouchi, Hiroyuki; Torii, Sho; Harari, Emanuel; Virmani, Renu; Finn, Aloke V

2017-11-01

Polymers are an essential component of drug-eluting stents (DES) used to control drug release but remain the most controversial component of DES technology. There are two types of polymers employed in DES: durable polymer based DES (DP-DES) and biodegradable polymer DES (BP-DES). First-generation DES were exclusively composed of DP and demonstrated increased rates of late stent failure due in part to poor polymer biocompatibility. Newer generations DES use more biocompatible durable polymers or biodegradable polymers. Areas covered: We will cover issues identified with 1st-generation DP-DES, areas of success and failure in 2nd-generation DP-DES and examine the promise and shortcomings of BP-DES. Briefly, fluorinated polymers used in 2nd-generation DP-DES have excellent anti-thrombogenicity and better biocompatibility than 1st-generation DES polymers. However, these devices lead to persistent drug exposure to the endothelium which impairs endothelial function and predisposes towards neoatherosclerosis. Meanwhile, BP-DES has shortened the duration of drug exposure which might be beneficial for endothelial functional recovery leading to less neoatherosclerosis. However, it remains uncertain whether the long-term biocompatibility of bare metal surfaces is better than that of polymer-coated metals. Expert commentary: Each technology has distinct advantages, which can be optimized depending upon the particular characteristics of the patient being treated.

Melt electrospinning of biodegradable polyurethane scaffolds

Science.gov (United States)

Karchin, Ari; Simonovsky, Felix I.; Ratner, Buddy D.; Sanders, Joan E.

2014-01-01

Electrospinning from the melt, in contrast to from solution, is an attractive tissue engineering scaffold manufacturing process as it allows for the formation of small diameter fibers while eliminating potentially cytotoxic solvents. Despite this, there is a dearth of literature on scaffold formation via melt electrospinning. This is likely due to the technical challenges related to the need for a well-controlled high temperature setup and the difficulty in developing an appropriate polymer. In this paper, a biodegradable and thermally stable polyurethane (PU) is described specifically for use in melt electrospinning. Polymer formulations of aliphatic PUs based on (CH2)4-content diisocyanates, polycaprolactone (PCL), 1,4-butanediamine and 1,4-butanediol (BD) were evaluated for utility in the melt electrospinning process. The final polymer formulation, a catalyst-purified PU based on 1,4-butane diisocyanate, PCL and BD in a 4/1/3 molar ratio with a weight-average molecular weight of about 40 kDa, yielded a nontoxic polymer that could be readily electrospun from the melt. Scaffolds electrospun from this polymer contained point bonds between fibers and mechanical properties analogous to many in vivo soft tissues. PMID:21640853

Natural rubber (NR) biosynthesis: perspectives from polymer chemistry

Energy Technology Data Exchange (ETDEWEB)

Barkakaty, Balaka [ORNL

2014-01-01

Natural rubber is an important strategic raw material for manufacturing a wide variety of industrial products. There are at least 2,500 different latex-producing plant species; however, only Hevea brasiliensis (the Brazilian rubber tree) is a commercial source. The chemical structure of natural rubber is cis-1,4-polyisoprene, but the exact structure of the head and end groups remains unknown. Since synthetic cis-1,4-polyisoprenes cannot match the superior properties of natural rubber, understanding the chemistry behind the biosynthetic process is key to finding a possible replacement. T his chapter summarizes our current understandings from the perspective of a polymer scientist by comparing synthetic polyisoprenes to natural rubber. The chapter also highlights biomimetic polymerization, research towards a synthetic match of natural rubber and the role of natural rubber in health care.

Coatings and Biodegradable and Bioasorbable Films

Science.gov (United States)

2006-12-28

Dielectric Spectroscopy ," Polymers for Biomedical Applications Symposium, ACS Fall 2006 Meeting, San Francisco, CA. 25 Novel Biodegradable Films Based on...groups upon cross-linking with HDI. The Figl2. Positron annihilation assessment hydroxyl groups are known to form fairly strong of free volume behavior of...1.26 e volume is accumulated upon cooling. Probing free- "A volume with positron life time spectroscopy 1.25 (PALS) showed that indeed, cross-linked

ROLE OF NATURAL POLYMER IN SUSTAINED AND CONTROLLED RELEASE

OpenAIRE

Vaishali S. Kadam, G. R. Shendarkar

2017-01-01

Now a day there has been an important development in different dosage forms for existing and newly designed drugs and natural products, and synthetic as well as semi-synthetic excipients always need to be used for a variety of purposes. Gums and mucilages are widely used as natural materials for conventional and novel dosage forms. With the increasing interest in polymers of natural origin, the pharmaceutical world has compliance to use most of them in their formulations. Moreover, the tremen...

New insights into polyurethane biodegradation and realistic prospects for the development of a sustainable waste recycling process.

Science.gov (United States)

Cregut, Mickael; Bedas, M; Durand, M-J; Thouand, G

2013-12-01

Polyurethanes are polymeric plastics that were first used as substitutes for traditional polymers suspected to release volatile organic hazardous substances. The limitless conformations and formulations of polyurethanes enabled their use in a wide variety of applications. Because approximately 10 Mt of polyurethanes is produced each year, environmental concern over their considerable contribution to landfill waste accumulation appeared in the 1990s. To date, no recycling processes allow for the efficient reuse of polyurethane waste due to their high resistance to (a)biotic disturbances. To find alternatives to systematic accumulation or incineration of polyurethanes, a bibliographic analysis was performed on major scientific advances in the polyurethane (bio)degradation field to identify opportunities for the development of new technologies to recondition this material. Until polymers exhibiting oxo- or hydro-biodegradative traits are generated, conventional polyurethanes that are known to be only slightly biodegradable are of great concern. The research focused on polyurethane biodegradation highlights recent attempts to reprocess conventional industrial polyurethanes via microbial or enzymatic degradation. This review describes several wonderful opportunities for the establishment of new processes for polyurethane recycling. Meeting these new challenges could lead to the development of sustainable management processes involving polymer recycling or reuse as environmentally safe options for industries. The ability to upgrade polyurethane wastes to chemical compounds with a higher added value would be especially attractive. © 2013.

Effect of ionizing radiation on the properties of prepared plastic/starch blends and their applications as biodegradable materials

International Nuclear Information System (INIS)

Khalil, S.A.

2010-01-01

Blends based on different ratios of plasticised starch (PLST), low density poly-ethyleen (LDPE) were prepared by mixing in extrouder. The LDPE/PLST/POMA (poly-olefin maleic anhydride) and LDPE/PLST/TMPTA (tri-methylol propane tri-acrylate) were exposed to different doses of electron beam. The effect of mixing and E-Beam irradiation on the thermal, mechanical, water absorption, and structure morphology properties were investigated. The results showed that the addition of compatibilizers and E-Beam irradiation improve all the physical properties, which provides suitable material based on natural polymer for biodegradable plastic.

R and D activities on radiation processing of natural polymers in Pakistan

International Nuclear Information System (INIS)

Yasin, Tariq

2008-01-01

The fishery industry in Pakistan is well established and is growing very fast. The annual production of shrimp is ∼45,000 metric ton, out of which ∼20,000 metric ton is exported. The annual production of crab is 250 metric ton. The estimated production of waste from these materials is approximately 20,000 metric ton, which is a huge quantity. This crustacean waste generated by fishery industries containing chitin, a natural polymer, can be extracted by chemical treatments. Deacetylation of chitin gives chitosan which is soluble in dilute mineral acids. Presently, the main consumer of this waste is animal feed industries. Pakistan Atomic Energy Commission (PAEC) has started research program on Radiation Processing of Natural Polymers in cooperation with IAEA and RCA in order to convert this sizable waste into value added products. This report describes some of our obtained results on radiation processing of natural polymer and its applications. (author)

Pathways for degradation of plastic polymers floating in the marine environment.

Science.gov (United States)

Gewert, Berit; Plassmann, Merle M; MacLeod, Matthew

2015-09-01

Each year vast amounts of plastic are produced worldwide. When released to the environment, plastics accumulate, and plastic debris in the world's oceans is of particular environmental concern. More than 60% of all floating debris in the oceans is plastic and amounts are increasing each year. Plastic polymers in the marine environment are exposed to sunlight, oxidants and physical stress, and over time they weather and degrade. The degradation processes and products must be understood to detect and evaluate potential environmental hazards. Some attention has been drawn to additives and persistent organic pollutants that sorb to the plastic surface, but so far the chemicals generated by degradation of the plastic polymers themselves have not been well studied from an environmental perspective. In this paper we review available information about the degradation pathways and chemicals that are formed by degradation of the six plastic types that are most widely used in Europe. We extrapolate that information to likely pathways and possible degradation products under environmental conditions found on the oceans' surface. The potential degradation pathways and products depend on the polymer type. UV-radiation and oxygen are the most important factors that initiate degradation of polymers with a carbon-carbon backbone, leading to chain scission. Smaller polymer fragments formed by chain scission are more susceptible to biodegradation and therefore abiotic degradation is expected to precede biodegradation. When heteroatoms are present in the main chain of a polymer, degradation proceeds by photo-oxidation, hydrolysis, and biodegradation. Degradation of plastic polymers can lead to low molecular weight polymer fragments, like monomers and oligomers, and formation of new end groups, especially carboxylic acids.

Biodegradation of flax fiber reinforced poly lactic acid

Directory of Open Access Journals (Sweden)

2010-07-01

Full Text Available Woven and nonwoven flax fiber reinforced poly lactic acid (PLA biocomposites were prepared with amphiphilic additives as accelerator for biodegradation. The prepared composites were buried in farmland soil for biodegradability studies. Loss in weight of the biodegraded composite samples was determined at different time intervals. The surface morphology of the biodegraded composites was studied with scanning electron microscope (SEM. Results indicated that in presence of mandelic acid, the composites showed accelerated biodegradation with 20–25% loss in weight after 50–60 days. On the other hand, in presence of dicumyl peroxide (as additive, biodegradation of the composites was relatively slow as confirmed by only 5–10% loss in weight even after 80–90 days. This was further confirmed by surface morphology of the biodegraded composites. We have attempted to show that depending on the end uses, we can add different amphiphilic additives for delayed or accelerated biodegradability. This work gives us the idea of biodegradation of materials from natural fiber reinforced PLA composites when discarded carelessly in the environment instead of proper waste disposal site.

Biodegradable Composites Based on Starch/EVOH/Glycerol Blends and Coconut Fibers

Science.gov (United States)

Unripe coconut fibers were used as fillers in a biodegradable polymer matrix of starch/Ethylene vinyl alcohol (EVOH)/glycerol. The effects of fiber content on the mechanical, thermal and structural properties were evaluated. The addition of coconut fiber into starch/EVOH/glycerol blends reduced the ...

Immobilization of metals in contaminated soils using natural polymer-based stabilizers.

Science.gov (United States)

Tao, Xue; Li, Aimin; Yang, Hu

2017-03-01

Three low-cost natural polymer materials, namely, lignin (Ln), carboxymethyl cellulose, and sodium alginate, were used for soil amendment to immobilize lead and cadmium in two contaminated soil samples collected from a mining area in Nanjing, China. The remediation effects of the aforementioned natural polymers were evaluated by toxicity characteristic leaching procedure (TCLP) and sequential extractions. The stabilizers could lower the bioavailability of Pb and Cd in the contaminated soils, and the amount of the exchangeable forms of the aforementioned two metals were reduced evidently. TCLP results showed that the leaching concentrations of Pb and Cd were decreased by 5.46%-71.1% and 4.25%-49.6%, respectively, in the treated soils. The contents of the organic forms of the two metals both increased with the increase in stabilizer dose on the basis of the redistribution of metal forms by sequential extractions. These findings were due to the fact that the abundant oxygen-containing groups on the polymeric amendments were effective in chelating and immobilizing Pb and Cd, which have been further confirmed from the metal adsorptions in aqueous solutions. Moreover, Ln achieved the greatest effect among the three polymers under study because of the former's distinct three-dimensional molecular structure, showing the preferential immobilization of Pb over Cd in soils also. Thus, the above-mentioned natural polymers hold great application potentials for reducing metal ion entry into the food chain at a field scale. Copyright © 2016 Elsevier Ltd. All rights reserved.

Microwave-enhanced synthesis of biodegradable multifunctional chitosan hydrogels for wastewater treatment

Directory of Open Access Journals (Sweden)

M. Piatkowski

2017-10-01

Full Text Available Chitosan, a derivative of chitin, is a biodegradable polymer known of its favorable properties, applicable in medicine and industry. Commonly obtained chitosan hydrogels are of various swelling capacity, and may bind only anions losing their susceptibility to biodegradation. Hydrogels are mostly obtained using toxic crosslinkers, which pollute environment due to waste generation during their synthesis. In the present article a novel, waste-free method for obtaining chitosan hydrogels under microwave irradiation, is described. Their chemical and morphological structure, swelling properties, sorption capability of a model dye and cadmium ions are described, and kinetic studies, were carried out. Biodegradability of the obtained hydrogels was investigated with the Sturm Test method. As a result, multifunctional chitosan hydrogels with both negative and positive surface charges and increased ability of anions and cations binding, were obtained. Materials were fully biodegradable, capable to absorb high amounts of water, as well as to remove various water contaminants.

Biodegradable Polyphosphazene-Based Blends for Regenerative Engineering.

Science.gov (United States)

Ogueri, Kenneth S; Escobar Ivirico, Jorge L; Nair, Lakshmi S; Allcock, Harry R; Laurencin, Cato T

2017-03-01

The occurrence of musculoskeletal tissue injury or disease and the subsequent functional impairment is at an alarming rate. It continues to be one of the most challenging problems in the human health care. Regenerative engineering offers a promising transdisciplinary strategy for tissues regeneration based on the convergence of tissue engineering, advanced materials science, stem cell science, developmental biology and clinical translation. Biomaterials are emerging as extracellular-mimicking matrices designed to provide instructive cues to control cell behavior and ultimately, be applied as therapies to regenerate damaged tissues. Biodegradable polymers constitute an attractive class of biomaterials for the development of scaffolds due to their flexibility in chemistry and the ability to be excreted or resorbed by the body. Herein, the focus will be on biodegradable polyphosphazene-based blend systems. The synthetic flexibility of polyphosphazene, combined with the unique inorganic backbone, has provided a springboard for more research and subsequent development of numerous novel materials that are capable of forming miscible blends with poly (lactide-co-glycolide) (PLAGA). Laurencin and co-workers has demonstrated the exploitation of the synthetic flexibility of Polyphosphazene that will allow the design of novel polymers, which can form miscible blends with PLAGA for biomedical applications. These novel blends, due to their well-tuned biodegradability, and mechanical and biological properties coupled with the buffering capacity of the degradation products, constitute ideal materials for regeneration of various musculoskeletal tissues. Regenerative engineering aims to regenerate complex tissues to address the clinical challenge of organ damage. Tissue engineering has largely focused on the restoration and repair of individual tissues and organs, but over the past 25 years, scientific, engineering, and medical advances have led to the introduction of this new

Biodegradable Polyphosphazene-Based Blends for Regenerative Engineering

Science.gov (United States)

Ogueri, Kenneth S.; Escobar Ivirico, Jorge L.; Nair, Lakshmi S.; Allcock, Harry R.; Laurencin, Cato T.

2017-01-01

The occurrence of musculoskeletal tissue injury or disease and the subsequent functional impairment is at an alarming rate. It continues to be one of the most challenging problems in the human health care. Regenerative engineering offers a promising transdisciplinary strategy for tissues regeneration based on the convergence of tissue engineering, advanced materials science, stem cell science, developmental biology and clinical translation. Biomaterials are emerging as extracellular-mimicking matrices designed to provide instructive cues to control cell behavior and ultimately, be applied as therapies to regenerate damaged tissues. Biodegradable polymers constitute an attractive class of biomaterials for the development of scaffolds due to their flexibility in chemistry and the ability to be excreted or resorbed by the body. Herein, the focus will be on biodegradable polyphosphazene-based blend systems. The synthetic flexibility of polyphosphazene, combined with the unique inorganic backbone, has provided a springboard for more research and subsequent development of numerous novel materials that are capable of forming miscible blends with poly (lactide-co-glycolide) (PLAGA). Laurencin and co-workers has demonstrated the exploitation of the synthetic flexibility of Polyphosphazene that will allow the design of novel polymers, which can form miscible blends with PLAGA for biomedical applications. These novel blends, due to their well-tuned biodegradability, and mechanical and biological properties coupled with the buffering capacity of the degradation products, constitute ideal materials for regeneration of various musculoskeletal tissues. Lay Summary Regenerative engineering aims to regenerate complex tissues to address the clinical challenge of organ damage. Tissue engineering has largely focused on the restoration and repair of individual tissues and organs, but over the past 25 years, scientific, engineering, and medical advances have led to the introduction of

A field evaluation of coated urea with biodegradable materials and ...

African Journals Online (AJOL)

ajl yemi

2011-12-28

Dec 28, 2011 ... Urease inhibitor and biodegradable polymer coatings are two most suitable startegies to increase urea fertilizer efficiency. Coating of urea with selected inhibitors can increase the crop production by slowing down the hydrolysis process of urea in the soil. For this purpose, a field experiment was conducted ...

A field evaluation of coated urea with biodegradable materials and ...

African Journals Online (AJOL)

Urease inhibitor and biodegradable polymer coatings are two most suitable startegies to increase urea fertilizer efficiency. Coating of urea with selected inhibitors can increase the crop production by slowing down the hydrolysis process of urea in the soil. For this purpose, a field experiment was conducted to evaluate the ...

Anaerobic biodegradation of hexazinone in four sediments

International Nuclear Information System (INIS)

Wang Huili; Xu Shuxia; Tan Chengxia; Wang Xuedong

2009-01-01

Anaerobic biodegradation of hexazinone was investigated in four sediments (L1, L2, Y1 and Y2). Results showed that the L2 sediment had the highest biodegradation potential among four sediments. However, the Y1 and Y2 sediments had no capacity to biodegrade hexazinone. Sediments with rich total organic carbon, long-term contamination history by hexazinone and neutral pH may have a high biodegradation potential because the former two factors can induce the growth of microorganisms responsible for biodegradation and the third factor can offer suitable conditions for biodegradation. The addition of sulfate or nitrate as electron acceptors enhanced hexazinone degradation. As expected, the addition of electron donors (lactate, acetate or pyruvate) substantially inhibited the degradation. In natural environmental conditions, the effect of intermediate A [3-(4-hydroxycyclohexyl)-6-(dimethylamino)-1-methyl-1,3,5-triazine-2,4(1H, 3H)dione] on anaerobic hexazinone degradation was negligible because of its low level.

Methyl tert-butyl ether biodegradation by indigenous aquifer microorganisms under natural and artificial oxic conditions

Science.gov (United States)

Landmeyer, J.E.; Chapelle, F.H.; Herlong, H.H.; Bradley, P.M.

2001-01-01

Microbial communities indigenous to a shallow groundwater system near Beaufort, SC, degraded milligram per liter concentrations of methyl tert-butyl ether (MTBE) under natural and artificial oxic conditions. Significant MTBE biodegradation was observed where anoxic, MTBE-contaminated groundwater discharged to a concrete-lined ditch. In the anoxic groundwater adjacent to the ditch, concentrations of MTBE were > 1 mg/L. Where groundwater discharge occurs, dissolved oxygen (DO) concentrations beneath the ditch exceeded 1.0 mg/L to a depth of 1.5 m, and MTBE concentrations decreased to CO2 in laboratory liquid culture studies, with no accumulation of intermediate compounds. Upgradient of the ditch in the anoxic, MTBE and BTEX-contaminated aquifer, addition of a soluble oxygen release compound resulted in oxic conditions and rapid MTBE biodegradation by indigenous microorganisms. In an observation well located closest to the oxygen addition area, DO concentrations increased from 0.4 to 12 mg/L in <60 days and MTBE concentrations decreased from 20 to 3 mg/L. In the same time period at a downgradient observation well, DO increased from <0.2 to 2 mg/L and MTBE concentrations decreased from 30 to <5 mg/L. These results indicate that microorganisms indigenous to the groundwater system at this site can degrade milligram per liter concentrations of MTBE under natural and artificial oxic conditions.

Preclinical investigation for developing injectable fiducial markers using a mixture of BaSO{sub 4} and biodegradable polymer for proton therapy

Energy Technology Data Exchange (ETDEWEB)

Ahn, Sang Hee [Department of Health Sciences and Technology, Samsung Advanced Institute for Health Sciences and Technology, Sungkyunkwan University, Seoul 135-710 (Korea, Republic of); Gil, Moon Soo; Lee, Doo Sung [Sungkyunkwan University School of Chemical Engineering, Suwon 440-746 (Korea, Republic of); Han, Youngyih, E-mail: youngyih@skku.edu, E-mail: Hee.ro.Park@samsung.com; Park, Hee Chul, E-mail: youngyih@skku.edu, E-mail: Hee.ro.Park@samsung.com; Yu, Jeong Il; Noh, Jae Myoung; Cho, Jun Sang; Ahn, Sung Hwan; Choi, Doo Ho [Department of Radiation Oncology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul 135-710 (Korea, Republic of); Sohn, Jason W. [Department of Radiation Oncology, Case Medical Center, Case Western Reserve University School of Medicine, Cleveland, Ohio 44106 (United States); Kim, Hye Yeong; Shin, Eun Hyuk [Department of Radiation Oncology, Samsung Medical Center, Seoul 135-710 (Korea, Republic of)

2015-05-15

Purpose: The aim of this study is to investigate the use of mixture of BaSO{sub 4} and biodegradable polymer as an injectable nonmetallic fiducial marker to reduce artifacts in x-ray images, decrease the absorbed dose distortion in proton therapy, and replace permanent metal markers. Methods: Two samples were made with 90 wt. % polymer phosphate buffer saline (PBS) and 10 wt. % BaSO{sub 4} (B1) or 20 wt. % BaSO{sub 4} (B2). Two animal models (mice and rats) were used. To test the injectability and in vivo gelation, a volume of 200 μl at a pH 5.8 were injected into the Sprague-Dawley rats. After sacrificing the rats over time, the authors checked the gel morphology. Detectability of the markers in the x-ray images was tested for two sizes (diameters of 1 and 2 mm) for B1 and B2. Four samples were injected into BALB/C mice. The polymer mixed with BaSO{sub 4} transform from SOL at 20 °C with a pH of 6.0 to GEL in the living body at 37 °C with a pH of 7.4, so the size of the fiducial marker could be controlled by adjusting the injected volume. The detectability of the BaSO{sub 4} marker was measured in x-ray images of cone beam CT (CBCT), on-board imager [anterior–posterior (AP), lateral], and fluoroscopy (AP, lateral) using a Novalis-TX (Varian Medical Systems, Palo Alto, CA) repeatedly over 4 months. The volume, HU, and artifacts for the markers were measured in the CBCT images. Artifacts were compared to those of gold marker by analyzing the HU distribution. The dose distortion in proton therapy was computed by using a Monte Carlo (MC) code. A cylindrical shaped marker (diameter: 1 or 2 mm, length: 3 mm) made of gold, stainless-steel [304], titanium, and 20 wt. % BaSO{sub 4} was positioned at the center of the spread-out Bragg peak (SOBP) in parallel or perpendicular to the beam entrance. The dose distortion was measured on the depth dose profile across the markers. Results: Transformation to GEL and the biodegradation were verified. All BaSO{sub 4} markers

Production of biodegradable plastic from agricultural wastes

Directory of Open Access Journals (Sweden)

N.A. Mostafa

2018-05-01

Full Text Available Agricultural residues management is considered to be a vital strategy in order to accomplish resource conservation and to maintain the quality of the environment. In recent years, biofibers have attracted increasing interest due to their wide applications in food packaging and in the biomedical sciences. These eco-friendly polymers reduce rapidly and replace the usage of the petroleum-based synthetic polymers due to their safety, low production costs, and biodegradability. This paper reports an efficient method for the production of the cellulose acetate biofiber from flax fibers and cotton linters. The used process satisfied a yield of 81% and 54% for flax fibers and cotton linters respectively (based on the weight of the cellulosic residue used. The structure of the produced bioplastic was confirmed by X-ray diffraction, FT-IR and gel permeation chromatography. Moreover, this new biopolymer is biodegradable and is not affected by acid or salt treatment but is alkali labile. A comparison test showed that the produced cellulose acetate was affected by acids to a lesser extent than polypropylene and polystyrene. Therefore, this new cellulose acetate bioplastics can be applied in both the food industry and medicine. Keywords: Cotton linters, Flax fibers, Cellulose acetate, Preparation, Characterization

Natural and synthetic polymers in fabric and home care applications

Science.gov (United States)

Paderes, Monissa; Ahirwal, Deepak; Fernández Prieto, Susana

2017-07-01

Polymers can be tailored to provide different benefits in Fabric & Home Care formulations depending on the monomers and modifications used, such as avoiding dye transfer inhibition in the wash, modifying the surface of tiles or increasing the viscosity and providing suspension properties to consumer products. Specifically, the rheology modification properties of synthetic and natural polymers are discussed in this chapter. The choice of a polymeric rheology modifier will depend on the formulation ingredients (charges, functional groups), the type and the amount of surfactants, the pH and the desired rheology modification. Natural polymeric rheology modifiers have been traditionally used in the food industry, being xanthan gum one of the most well-known ones. On the contrary, synthetic rheology modifiers are preferably used in paints & coats, textile printing and cleaning products.

Biodegradable conductive composites of poly(3-hydroxybutyrate and polyaniline nanofibers: Preparation, characterization and radiolytic effects

Directory of Open Access Journals (Sweden)

2011-01-01

Full Text Available Poly(3-hydroxybutyrate is a biodegradable polyester produced by microorganisms under nutrient limitation conditions. We obtained a biodegradable poly(3-hydroxybutyrate composite having 8 to 55% of chemically in situ polymerized hydrochloric acid-doped polyaniline nanofibers (70-100 nm in diameter. Fourier transform infrared spectroscopy and X-rays diffractometry data did not show evidence of significant interaction between the two components of the nanocomposite, and polyaniline semiconductivity was preserved in all studied compositions. Gamma-irradiation at 25 kGy absorbed dose on the semiconductive composite presenting 28% of doped polyaniline increased its conductivity from 4.6*10-2 to 1.1 S/m, while slightly decreasing its biodegradability. PANI-HCl biodegradation is negligible when compared to PHB biodegradability in an 80 day timeframe. Thus, this unprecedented all-polymer nanocomposite presents, at the same time, semiconductivity and biodegradability and was proven to maintain these properties after gamma irradiation. This new material has many potential applications in biological science, engineering, and medicine.

Progress in radiation processing of polymers

Science.gov (United States)

Chmielewski, Andrzej G.; Haji-Saeid, Mohammad; Ahmed, Shamshad

2005-07-01

Modification in polymeric structure of plastic material can be brought either by conventional chemical means or by exposure to ionization radiation from ether radioactive sources or highly accelerated electrons. The prominent drawbacks of chemical cross-linking typically involve the generation of noxious fumes and by products of peroxide degradation. Both the irradiation sources have their merits and limitations. Increased utilization of electron beams for modification and enhancement of polymer materials has been in particular witnessed over the past 40 years. The paper highlights several recent cases of EB utilization to improve key properties of selected plastic products. In paper is provided a survey of radiation processing methods of industrial interest, encompassing technologies which are already commercially well established, through developments in the active R&D stage which show pronounced promise for future commercial use. Radiation cross-linking technologies discussed include: application in cable and wire, application in rubber tyres, radiation vulcanization of rubber latex, development of radiation crosslinked SiC fiber, polymer recycling, development of gamma compatible pp, hydrogels etc. Over the years, remarkable advancement has been achieved in radiation processing of natural polymers. Role of radiation in improving the processing of temperature of PCL for use as biodegradable polymer, in accelerated breakdown of cellulose into viscose and enhancement in yields of chitin/chitosan from sea-food waste, is described.

Progress in radiation processing of polymers

Energy Technology Data Exchange (ETDEWEB)

Chmielewski, Andrzej G. [International Atomic Energy Agency, Industrial Applications and Chemistry Section, Division of Physical and Chemical Sciences, Department of Nuclear Sciences and Applications, Wagramer Street 5, Vienna 1400 (Austria) and Department of Process and Chemical Engineering, Warsaw University of Technology, Warsaw (Poland)]. E-mail: a-g.chmielewski@iaea.org; Haji-Saeid, Mohammad [International Atomic Energy Agency, Industrial Applications and Chemistry Section, Division of Physical and Chemical Sciences, Department of Nuclear Sciences and Applications, Wagramer Street 5, Vienna 1400 (Austria); Ahmed, Shamshad [Applied Chemistry Laboratories, Pakistan Institute of Nuclear Science and Technology, P.O. Box Nilore, Islamabad (Pakistan)

2005-07-01

Modification in polymeric structure of plastic material can be brought either by conventional chemical means or by exposure to ionization radiation from ether radioactive sources or highly accelerated electrons. The prominent drawbacks of chemical cross-linking typically involve the generation of noxious fumes and by products of peroxide degradation. Both the irradiation sources have their merits and limitations. Increased utilization of electron beams for modification and enhancement of polymer materials has been in particular witnessed over the past 40 years. The paper highlights several recent cases of EB utilization to improve key properties of selected plastic products. In paper is provided a survey of radiation processing methods of industrial interest, encompassing technologies which are already commercially well established, through developments in the active R and D stage which show pronounced promise for future commercial use. Radiation cross-linking technologies discussed include: application in cable and wire, application in rubber tyres, radiation vulcanization of rubber latex, development of radiation crosslinked SiC fiber, polymer recycling, development of gamma compatible pp, hydrogels etc. Over the years, remarkable advancement has been achieved in radiation processing of natural polymers. Role of radiation in improving the processing of temperature of PCL for use as biodegradable polymer, in accelerated breakdown of cellulose into viscose and enhancement in yields of chitin/chitosan from sea-food waste, is described.

Progress in radiation processing of polymers

International Nuclear Information System (INIS)

Chmielewski, Andrzej G.; Haji-Saeid, Mohammad; Ahmed, Shamshad

2005-01-01

Modification in polymeric structure of plastic material can be brought either by conventional chemical means or by exposure to ionization radiation from ether radioactive sources or highly accelerated electrons. The prominent drawbacks of chemical cross-linking typically involve the generation of noxious fumes and by products of peroxide degradation. Both the irradiation sources have their merits and limitations. Increased utilization of electron beams for modification and enhancement of polymer materials has been in particular witnessed over the past 40 years. The paper highlights several recent cases of EB utilization to improve key properties of selected plastic products. In paper is provided a survey of radiation processing methods of industrial interest, encompassing technologies which are already commercially well established, through developments in the active R and D stage which show pronounced promise for future commercial use. Radiation cross-linking technologies discussed include: application in cable and wire, application in rubber tyres, radiation vulcanization of rubber latex, development of radiation crosslinked SiC fiber, polymer recycling, development of gamma compatible pp, hydrogels etc. Over the years, remarkable advancement has been achieved in radiation processing of natural polymers. Role of radiation in improving the processing of temperature of PCL for use as biodegradable polymer, in accelerated breakdown of cellulose into viscose and enhancement in yields of chitin/chitosan from sea-food waste, is described

The Molecular Level Characterization of Biodegradable Polymers Originated from Polyethylene Using Non-Oxygenated Polyethylene Wax as a Carbon Source for Polyhydroxyalkanoate Production.

Science.gov (United States)

Johnston, Brian; Jiang, Guozhan; Hill, David; Adamus, Grazyna; Kwiecień, Iwona; Zięba, Magdalena; Sikorska, Wanda; Green, Matthew; Kowalczuk, Marek; Radecka, Iza

2017-08-28

There is an increasing demand for bio-based polymers that are developed from recycled materials. The production of biodegradable polymers can include bio-technological (utilizing microorganisms or enzymes) or chemical synthesis procedures. This report demonstrates the corroboration of the molecular structure of polyhydroxyalkanoates (PHAs) obtained by the conversion of waste polyethylene (PE) via non-oxygenated PE wax (N-PEW) as an additional carbon source for a bacterial species. The N-PEW, obtained from a PE pyrolysis reaction, has been found to be a beneficial carbon source for PHA production with Cupriavidus necator H16. The production of the N-PEW is an alternative to oxidized polyethylene wax (O-PEW) (that has been used as a carbon source previously) as it is less time consuming to manufacture and offers fewer industrial applications. A range of molecular structural analytical techniques were performed on the PHAs obtained; which included nuclear magnetic resonance (NMR) and electrospray ionisation tandem mass spectrometry (ESI-MS/MS). Our study showed that the PHA formed from N-PEW contained 3-hydroxybutyrate (HB) with 11 mol% of 3-hydroxyvalerate (HV) units.

Electrical characterization of proton conducting polymer electrolyte based on bio polymer with acid dopant

Energy Technology Data Exchange (ETDEWEB)

Kalaiselvimary, J.; Pradeepa, P.; Sowmya, G.; Edwinraj, S.; Prabhu, M. Ramesh, E-mail: email-mkram83@gmail.com [Department of Physics, Alagappa University, Karaikudi – 630 004, India. (India)

2016-05-06

This study describes the biodegradable acid doped films composed of chitosan and Perchloric acid with different ratios (2.5 wt %, 5 wt %, 7.5 wt %, 10 wt %) was prepared by the solution casting technique. The temperature dependence of the proton conductivity of complex electrolytes obeys the Arrhenius relationship. Proton conductivity of the prepared polymer electrolyte of the bio polymer with acid doped was measured to be approximately 5.90 × 10{sup −4} Scm{sup −1}. The dielectric data were analyzed using Complex impedance Z*, Dielectric loss ε’, Tangent loss for prepared polymer electrolyte membrane with the highest conductivity samples at various temperature.

Vascularization and tissue infiltration of a biodegradable polyurethane matrix

Science.gov (United States)

Ganta, Sudhakar R.; Piesco, Nicholas P.; Long, Ping; Gassner, Robert; Motta, Luis F.; Papworth, Glenn D.; Stolz, Donna B.; Watkins, Simon C.; Agarwal, Sudha

2016-01-01

Urethanes are frequently used in biomedical applications because of their excellent biocompatibility. However, their use has been limited to bioresistant polyurethanes. The aim of this study was to develop a nontoxic biodegradable polyurethane and to test its potential for tissue compatibility. A matrix was synthesized with pentane diisocyanate (PDI) as a hard segment and sucrose as a hydroxyl group donor to obtain a microtextured spongy urethane matrix. The matrix was biodegradable in an aqueous solution at 37°C in vitro as well as in vivo. The polymer was mechanically stable at body temperatures and exhibited a glass transition temperature (Tg) of 67°C. The porosity of the polymer network was between 10 and 2000 µm, with the majority of pores between 100 and 300 µm in diameter. This porosity was found to be adequate to support the adherence and proliferation of bone-marrow stromal cells (BMSC) and chondrocytes in vitro. The degradation products of the polymer were nontoxic to cells in vitro. Subdermal implants of the PDI–sucrose matrix did not exhibit toxicity in vivo and did not induce an acute inflammatory response in the host. However, some foreign-body giant cells did accumulate around the polymer and in its pores, suggesting its degradation is facilitated by hydrolysis as well as by giant cells. More important, subdermal implants of the polymer allowed marked infiltration of vascular and connective tissue, suggesting the free flow of fluids and nutrients in the implants. Because of the flexibility of the mechanical strength that can be obtained in urethanes and because of the ease with which a porous microtexture can be achieved, this matrix may be useful in many tissue-engineering applications. PMID:12522810

Petroleum biodegradation and oil spill bioremediation

International Nuclear Information System (INIS)

Atlas, R.M.

1995-01-01

Hydrocarbon-utilizing microorganisms are ubiquitously distributed in the marine environment following oil spills. These microorganisms naturally biodegrade numerous contaminating petroleum hydrocarbons, thereby cleansing the oceans of oil pullutants. Bioremediation, which is accomplished by adding exogenous microbial populations or stimulating indigenous ones, attempts to raise the rates of degradation found naturally to significantly higher rates. Seeding with oil degraders has not been demonstrated to be effective, but addition of nitrogenous fertilizers has been shown to increase rates of petroleum biodegradation. In the case of the Exxon Valdez spill, the largest and most thoroughly studied application of bioremediation, the application of fertilizer (slow release or oleophilic) increased rates of biodegradation 3-5 times. Because of the patchiness of oil, an internally conserved compound, hopane, was critical for demonstrating the efficacy of bioremediation. Multiple regression models showed that the effectiveness of bioremediation depended upon the amount of nitrogen delivered, the concentration of oil, and time. (author)

The studies on waste biodegradation by Tenebrio molitor

Directory of Open Access Journals (Sweden)

Bożek Magdalena

2017-01-01

Full Text Available As cities are growing in size with a rise in the population, the amount of plastic waste generated is increasing and becoming unmanageable. The treatment and disposal of plastic waste is an urgent need of our present and future. It has been proved recently that mealworms, the larvae of Tenebrio molitor Linnaeus, are able eat styrofoam, a common polystyrene product. Polystyrene is one of the most widely used plastics, the scale of its production being several million tons per year. Tenebrio molitor is one of the largest pests found in stored-grain products. The insect is indigenous to Europe, but is currently cosmopolitan in distribution. The styrofoam is efficiently degraded in the larval gut by microorganisms. We have used the larvae of T. molitor to biodegrade three types of food packaging plastics: polystyrene (PS, polyvinyl chloride (PVC and polylactide (PLA. PVC is a thermoplastic made of 57% chlorine (derived from industrial grade salt and 43% carbon (derived predominantly from oil /gas via ethylene. It is the world's third-most widely produced synthetic plastic polymer, which is not biodegradable easily. On the other hand, PLA is an easily biodegradable and bioactive thermoplastic aliphatic polyester derived from corn and tapioca starch or sugarcane. Three groups of larvae were fed selected types of polymers as an only food, while a control population was fed on oatmeal. The mass loss, dry matter content and biochemical composition of mealworms were assessed in the performed laboratory experiments. The protein concentration in homogenates of the larvae was determined by the Bradford method. To determine the level of hydrolized carbohydrates we used anthrone method. The classical sulfo-phospho-vanillin assay (SPVA was used to quantitate total lipids in mealworms. The results allowed to compare the decomposition efficiency of selected polymer materials by mealworms and to recognize the mechanism of decomposition contributing to the future

Current Status of Radiation Processing of Natural Polymers in India

International Nuclear Information System (INIS)

Ramnani, S.P.

2010-01-01

Radiation processing is being used on commercial basis in India since 1974 with the operation of ISOMED plant for radiation sterilization of medical products and Electron beam machine (ILU-6) in 1986. Since then many new products and processes have been investigated and some of them have culminated into useful applications. Many Indian industries produce and process natural polymers for local consumption and export. India exports about 120,000 tons of polysaccharides every year. Natural polysaccharides like guar gum, gum acacia, gum tora, agar, psylium husk etc are treated with gamma radiation mainly for controlling microbial contamination and sterilization. Radiation processing has also been used to reduce molecular weight of the polysaccharides in some applications. Recently, a few new applications have emerged where natural polysaccharides are used as additives and which play important role in controlling basic radiation chemistry reactions to produce useful products. Developed at BARC, radiation processed wound dressings, superabsorbent materials and low molecular weight chitosan are the products which have been used and could find potential applications in health care and agriculture sector. Radiation processed hydrogel wound dressings containing natural polysaccharides have already been commercialized. Some of the applications recently developed at BARC using natural polymers are briefly described below

Blendas PHB/copoliésteres biodegradáveis : biodegradação em solo Biodegradable PHB/copolyester blends : biodegradation in soil

Directory of Open Access Journals (Sweden)

Suzan A. Casarin

2013-01-01

Full Text Available Este trabalho apresenta os resultados do comportamento de blendas do polímero biodegradável PHB poli(hidroxibutirato com os copoliésteres também biodegradáveis EastarBio® e Ecoflex®, na composição de 75% de PHB e 25% dos copoliésteres, em contato com solo composto simulado. Foi também avaliada a influência da adição de pó de serra ou farinha de madeira, na proporção de 70% da blenda e 30% de pó de serra (p.d.s.. A biodegradação foi avaliada para amostras após 30, 60 e 90 dias em contato com solo, através de análises gravimétricas, morfológicas e mecânicas. A preparação inicial dos grânulos dos compostos poliméricos foi feita por extrusão, utilizando uma extrusora dupla-rosca e a moldagem dos corpos de prova foi realizada através da moldagem por injeção. Os materiais estudados biodegradam nas condições testadas. A blenda PHB/EastarBio® (75/25 + 30% p.d.s. apresentou maior redução de massa, 29% após 90 dias. Notou-se que a biodegradação se inicia pela superfície do material e que 90 dias são insuficientes para observar alterações internas.This paper reports on blends made with the biodegradable polymers poly(hydroxybutyrate (PHB and Eastar Bio® or Ecoflex® copolyesters, in contact with simulated compound soil. The blends had 75% of PHB and 25% of copolyesters. We also analyzed the influence from adding 30% of powder-wood or wood flour (WPC to 70% of the blend. Biodegradation was analyzed for samples after 30, 60 and 90 days in contact with soil, through thermogravimetric, morphological and mechanical analyses. The initial preparation of the granules of polymeric compounds was made by extrusion, using a twin-screw extruder and the molding of the specimens was performed by injection molding. The analysis indicated material biodegradation under the conditions tested. The PHB/Eastar Bio® blend (75/25 + 30% WPC exhibited the highest degradation with 29% of mass loss at the end of 90 days. Biodegradation

Biodegradation behavior of natural organic matter (NOM) in a biological aerated filter (BAF) as a pretreatment for ultrafiltration (UF) of river water

KAUST Repository

Huang, Guocheng; Meng, Fangang; Zheng, Xing; Wang, Yuan; Wang, Zhigang; Liu, Huijun; Jekel, Martin R.

2011-01-01

In this study, biodegradation of natural organic matter (NOM) in a biological aerated filter (BAF) as pretreatment of UF treating river water was investigated. Photometric measurement, three-dimensional excitation-emission matrix (EEM) fluorescence

DESIGN AND EVALUATION OF LOSARTAN POTASSIUM MATRIX TABLETS WITH NATURAL AND SYNTHETIC POLYMERS

OpenAIRE

R. L. C. Sasidhar et al.

2012-01-01

The objective of the study was to formulate controlled release matrix tablets of losartan Potassium by using a combination of hydrophilic synthetic polymer like poly (ethylene oxides) and natural gums like xanthan gum, karaya gum and guar gum. A combination of synthetic hydrophobic polymers like methacrylates with synthetic hydrophilic polymer like poly (ethylene oxide) was also used in the preparation of matrix tablets and evaluated for their influence on controlled drug release. The matrix ...

Experimental testing and numerical simulation on natural composite for aerospace applications

Science.gov (United States)

Kumar, G. Raj; Vijayanandh, R.; Kumar, M. Senthil; Kumar, S. Sathish

2018-05-01

Nowadays polymers are commonly used in various applications, which make it difficult to avoid its usage even though it causes environmental problems. Natural fibers are best alternate to overcome the polymer based environmental issues. Natural fibers play an important role in developing high performing fully newline biodegradable green composites which will be a key material to solve environmental problems in future. In this paper deals the properties analysis of banana fiber is combined with epoxy resin in order to create a natural composite, which has special characteristics for aerospace applications. The objective of this paper is to investigate the characteristics of failure modes and strength of natural composite using experimental and numerical methods. The test specimen of natural composite has been fabricated as per ASTM standard, which undergoes tensile and compression tests using Tinius Olsen UTM in order to determine mechanical and physical properties. The reference model has been designed by CATIA, and then numerical simulation has been carried out by Ansys Workbench 16.2 for the given boundary conditions.

Biodegradation of ion-exchange media

International Nuclear Information System (INIS)

Bowerman, B.S.; Clinton, J.H.; Cowdery, S.R.

1988-08-01

Ion-exchange media, both bead resins and powdered filter media, are used in nuclear power plants to remove radioactivity from process water prior to reuse or environmental discharge. Since the ion- exchange media are made from synthetic hydrocarbon-based polymers, they may be susceptible to damage from biological activity. The purpose of this study was to investigate some of the more basic aspects of biodegradation of ion-exchange media, specifically to evaluate the ability of microorganisms to utilize the ion-exchange media or materials sorbed on them as a food source. The ASTM-G22 test, alone and combined with the Bartha Pramer respirometric method, failed to indicate the biodegradability of the ion-exchange media. The limitation of these methods was that they used a single test organism. In later phases of this study, a mixed microbial culture was grown from resin waste samples obtained from the BNL High Flux Beam Reactor. These microorganisms were used to evaluate the susceptibility of different types of ion-exchange media to biological attack. Qualitative assessments of biodegradability were based on visual observations of culture growths. Greater susceptibility was associated with increased turbidity in solution indicative of bacterial growth, and more luxuriant fungal mycelial growth in solution or directly on the ion-exchange resin beads. 21 refs., 9 figs., 18 tabs

Flexible biodegradable citrate-based polymeric step-index optical fiber.

Science.gov (United States)

Shan, Dingying; Zhang, Chenji; Kalaba, Surge; Mehta, Nikhil; Kim, Gloria B; Liu, Zhiwen; Yang, Jian

2017-10-01

Implanting fiber optical waveguides into tissue or organs for light delivery and collection is among the most effective ways to overcome the issue of tissue turbidity, a long-standing obstacle for biomedical optical technologies. Here, we report a citrate-based material platform with engineerable opto-mechano-biological properties and demonstrate a new type of biodegradable, biocompatible, and low-loss step-index optical fiber for organ-scale light delivery and collection. By leveraging the rich designability and processibility of citrate-based biodegradable polymers, two exemplary biodegradable elastomers with a fine refractive index difference and yet matched mechanical properties and biodegradation profiles were developed. Furthermore, we developed a two-step fabrication method to fabricate flexible and low-loss (0.4 db/cm) optical fibers, and performed systematic characterizations to study optical, spectroscopic, mechanical, and biodegradable properties. In addition, we demonstrated the proof of concept of image transmission through the citrate-based polymeric optical fibers and conducted in vivo deep tissue light delivery and fluorescence sensing in a Sprague-Dawley (SD) rat, laying the groundwork for realizing future implantable devices for long-term implantation where deep-tissue light delivery, sensing and imaging are desired, such as cell, tissue, and scaffold imaging in regenerative medicine and in vivo optogenetic stimulation. Copyright © 2017 Elsevier Ltd. All rights reserved.

Intrinsic bacterial biodegradation of petroleum contamination demonstrated in situ using natural abundance, molecular-level 14C analysis

International Nuclear Information System (INIS)

Slater, G.F.; Nelson, R.K.; Kile, B.M.; Reddy, C.M.

2006-01-01

Natural abundance, molecular-level C 14 analysis was combined with comprehensive gas chromatography (GC x GC) to investigate, in situ, the role of intrinsic biodegradation in the loss of petroleum hydrocarbons from the rocky, inter-tidal zone impacted by the Bouchard 120 oil spill. GC x GC analysis indicated accelerated losses of n-alkane components of the residual petroleum hydrocarbons between day 40 and day 50 after the spill. 14 C analysis of bacterial phospholipid fatty acids (PLFA) from the impacted zone on day 44 showed that the polyunsaturated fatty acids attributed to the photoautotrophic component of the microbial community had the same ( 14 C as the local dissolved inorganic carbon (DIG), indicating that this DIG was their carbon source. In contrast there was significant (C depletion in the saturated and mono-unsaturated PLFA indicating incorporation of petroleum carbon. This correlation between the observed accelerated n-alkane losses and microbial incorporation of (C-depleted carbon directly demonstrated, in situ, that intrinsic biodegradation was affecting the petroleum. Since the majority of organic contaminants originate from petroleum feed-stocks, in situ molecular-level 14 C analysis of microbial PLFA can provide insights into the occurrence and pathways of biodegradation of a wide range of organic contaminants. (Author)

Proceedings of the Takasaki symposium on radiation processing of natural polymers

International Nuclear Information System (INIS)

Kume, Tamikazu; Maekawa, Yasunari

2001-03-01

This Takasaki symposium was held as enlargement of the Takasaki workshop on bilateral cooperations for radiation processing of natural polymers in 1999. The attendants were increased from 61 to 80 due to the expansion from five bilateral cooperation countries last year to further 3 Asian countries. At the symposium, the enhancement effects of plant growth and antifungal activity by radiation-degraded carbohydrates, hydrogels as a wound dressing material, and production of an protein free natural rubber grove were of major concern. Many domestic and foreign attendants were especially interested in novel functionality of radiation treated natural polymers and exchanged their opinions actively. Furthermore, since outstanding researchers in this field were invited from the Asian countries, we could also exchange the opinions about the present situation of the research activities interregional cooperation of the radiation processing in Asia. The 27 of the presented papers are indexed individually. (J.P.N.)

Biodegradation of oils in uranium deposits

International Nuclear Information System (INIS)

Landais, P.

1989-01-01

The biodegradation of free hydrocarbons that have migrated in reservoir facies has often been observed in the field of petroleum exploration. This alteration is characterized by the progressive removal by bacteria of the different types of hydrocarbons: n-alkanes, branched alkanes, aromatics, cycloalkanes, etc. One of the most important consequences of biodegradation is the biogenic reduction of sulphate, which has been noticed in several Pb-Zn deposits. Biodegradation of oils spatially associated with uranium mineralizations has been observed in Temple Mountain, Utah, and the Grand Canyon, Arizona, in the United States of America, and in Lodeve in France. It leads to the transformation of fluid oils into solid bitumens. Emphasis is placed on the relationships between the effects of biodegradation on organic matter (oxidation of aromatization) and the nature of aqueous fluids analysed in fluid inclusions trapped in authigenic minerals. Different mechanisms are proposed to explain the transformations of organic matter during biodegradation and their possible links with the ore forming process. (author). 40 refs, 13 figs, 1 tab

Biodegradation behavior of natural organic matter (NOM) in a biological aerated filter (BAF) as a pretreatment for ultrafiltration (UF) of river water

KAUST Repository

Huang, Guocheng

2011-04-15

In this study, biodegradation of natural organic matter (NOM) in a biological aerated filter (BAF) as pretreatment of UF treating river water was investigated. Photometric measurement, three-dimensional excitation-emission matrix (EEM) fluorescence spectroscopy and liquid chromatography with online organic carbon detector (LC-OCD) were used to investigate the fate of NOM fractions in the BAF+UF process. Results showed that the BAF process could effectively remove particles and parts of dissolved organic matter, which led to a lower NOM loading in the UF system, but different NOM fractions showed different biodegradation potentials. Further biodegradation batch experiments confirmed this observation and identified that polysaccharides and proteins (quantified using photometric methods) contained a large proportion of readily biodegradable matter while humic substances were mainly composed of inert organic substances. According to EEM measurements, it is evident that protein-like substances were more readily eliminated by microorganisms than humic-like substances. LC-OCD data also supported the phenomena that the polysaccharides and large-size proteins were more degradable than humic substances. © 2011 Springer-Verlag.

Biodegradation polyurethane derived from vegetable oil irradiated with gamma rays 25 kGy and 100 kGy

International Nuclear Information System (INIS)

Santos, Antonia M. dos; Claro Neto, Salvador; Azevedo, Elaine C. de

2011-01-01

The environment requires polymers that can be degraded by the action of microorganisms. In this work was studied the biodegradation of polyurethane samples derived from vegetable oil (castor oil), which were irradiated with gamma rays 25 kGy and 100 kGy compared with the same polyurethane without being irradiated. Biodegradation of polyurethane was carried out in culture medium containing the fungus Aspergillus niger by 146 days and the result was evaluated using the technique of thermogravimetric analysis, where there was a change of behavior of the curves TGA / DTG occurred indicating that chemical modifications of molecules present in the structure of the polymer chain, thus confirming that the material has undergone the action of microorganisms. (author)

Controlled Release from Recombinant Polymers

Science.gov (United States)

Price, Robert; Poursaid, Azadeh; Ghandehari, Hamidreza

2014-01-01

Recombinant polymers provide a high degree of molecular definition for correlating structure with function in controlled release. The wide array of amino acids available as building blocks for these materials lend many advantages including biorecognition, biodegradability, potential biocompatibility, and control over mechanical properties among other attributes. Genetic engineering and DNA manipulation techniques enable the optimization of structure for precise control over spatial and temporal release. Unlike the majority of chemical synthetic strategies used, recombinant DNA technology has allowed for the production of monodisperse polymers with specifically defined sequences. Several classes of recombinant polymers have been used for controlled drug delivery. These include, but are not limited to, elastin-like, silk-like, and silk-elastinlike proteins, as well as emerging cationic polymers for gene delivery. In this article, progress and prospects of recombinant polymers used in controlled release will be reviewed. PMID:24956486

Identification of market bags composition for biodegradable and oxo-biodegradable samples through thermal analysis in inert and oxidizer atmosphere; Identificacao da composicao de amostras de sacolas plasticas biodegradaveis e oxobiodegradaveis atraves de analises termicas em atmosfera inerte e oxidante

Energy Technology Data Exchange (ETDEWEB)

Finzi-Quintao, Cristiane M., E-mail: inzi@ufsj.edu.br [Universidade Federal de Sao Joao del-Rei (UFSJ), MG (Brazil); Novack, Katia M. [Universidade Federal de Ouro Preto (DEQUI/UFOP), MG (Brazil)

2015-07-01

Plastic films used to make market bags are based on polymers such as polyethylene, polystyrene and polypropylene, these materials require a long time to degrade in the environment. The alternative technologies of polymers have been developed to reduce the degradation time and the impact on the environment caused by the conventional materials, using pro-degrading additives or by the development biodegradable polymers. In Brazil, the laws of some municipalities require the use of biodegradable material in the production of market bags but the absence of specific surveillance policies makes its chemical composition unknown. In this paper, we analyzed 7 samples that was obtained from a a trading company and commercial market of Belo Horizonte . The samples were characterized by TGA / DTA , XRF , FTIR and MEV which allowed the identification and evaluation of the thermal behavior of the material in inert and oxidizing atmosphere. (author)

Biodegradable polymeric microsphere-based drug delivery for inductive browning of fat

Directory of Open Access Journals (Sweden)

Chunhui eJiang

2015-11-01

Full Text Available Brown and beige adipocytes are potent therapeutic agents to increase energy expenditure and reduce risks of obesity and its affiliated metabolic symptoms. One strategy to increase beige adipocyte content is through inhibition of the evolutionarily conserved Notch signaling pathway. However, systemic delivery of Notch inhibitors is associated with off-target effects and multiple dosages of application further faces technical and translational challenges. Here, we report the development of a biodegradable polymeric microsphere-based drug delivery system for sustained, local release of a Notch inhibitor, DBZ. The microsphere-based delivery system was fabricated and optimized using an emulsion/solvent evaporation technique to encapsulate DBZ into poly(lactide-co-glycolide (PLGA, a commonly used biodegradable polymer for controlled drug release. Release studies revealed the ability of PLGA microspheres to release DBZ in a sustained manner. Co-culture of white adipocytes with and without DBZ-loaded PLGA microspheres demonstrated that the released DBZ retained its bioactivity, and effectively inhibited Notch and promoted browning of white adipocytes. Injection of these DBZ-loaded PLGA microspheres into mouse inguinal white adipose tissue (WAT depots resulted in browning in vivo. Our results provide the encouraging proof-of-principle evidence for the application of biodegradable polymers as a controlled release platform for delivery of browning factors, and pave the way for development of new translational therapeutic strategies for treatment of obesity.

Biodegradable polyurethane nanocomposites containing dexamethasone for ocular route

Energy Technology Data Exchange (ETDEWEB)

Rodrigues da Silva, Gisele [Federal University of Sao Joao Del Rei, School of Pharmacy, Divinopolis, Minas Gerais (Brazil); Silva-Cunha, Armando da [Federal University of Minas Gerais, School of Pharmacy, Belo Horizonte, Minas Gerais (Brazil); Behar-Cohen, Francine [INSERM, Physiopathology of ocular diseases: Therapeutic innovations, Institut des Cordeliers, Paris (France); Laboratoire d' Innovations Therapeutiques, Fondation Rothschild, Paris (France); Universite Rene Descartes, Hotel Dieu University Hospital, Paris (France); Ayres, Eliane [Federal University of Minas Gerais, Department of Metallurgical and Materials Engineering, Belo Horizonte, Minas Gerais (Brazil); Orefice, Rodrigo L., E-mail: rorefice@demet.ufmg.br [Federal University of Minas Gerais, Department of Metallurgical and Materials Engineering, Belo Horizonte, Minas Gerais (Brazil)

2011-03-12

The treatment of posterior segment ocular diseases, such as uveitis, by using eye drops and oral drugs is usually not effective due to the body's natural barriers to drug penetration. In this study, ocular implants to treat uveitis were synthesized by incorporating dexamethasone acetate, an important type of corticoid used in the treatment of some uveitis, into a biodegradable polyurethane containi clay nanoparticles. Biodegradable polyurethane nanocomposites having poly(caprolactone) oligomers as soft segments were obtained by delaminating clay particles within a polyurethane aqueous dispersion. The drug was incorporated into the polymer by dispersing it in the waterborne polyurethane followed by a drying step. Nanoparticles derived from clay were demonstrated to be able to tailor the mechanical properties of polyurethanes to achieve values that can match the properties of ocular soft tissues. Infrared spectra (FTIR) showed that the presence of clay particles was able to change the microphase separation process typical of polyurethanes. X-ray diffraction and small angle x-ray scattering (SAXS) results were explored to show that the incorporation of both dexamethasone acetate and nanocomponents derived from clay led to a less defined two-phase polyurethane. The presence of clay nanoparticles increased the rate of drug release measured in vitro. Human retinal pigment epithelial cells (ARPE-19) were cultured in contact with polyurethanes and polyurethane nanocomposites, and the viability of them (evaluated by using MTT assay after 7 days) showed that no toxic components were released from polyurethanes containing no drugs during the test.

Biodegradable polyurethane nanocomposites containing dexamethasone for ocular route

International Nuclear Information System (INIS)

Rodrigues da Silva, Gisele; Silva-Cunha, Armando da; Behar-Cohen, Francine; Ayres, Eliane; Orefice, Rodrigo L.

2011-01-01

The treatment of posterior segment ocular diseases, such as uveitis, by using eye drops and oral drugs is usually not effective due to the body's natural barriers to drug penetration. In this study, ocular implants to treat uveitis were synthesized by incorporating dexamethasone acetate, an important type of corticoid used in the treatment of some uveitis, into a biodegradable polyurethane containi clay nanoparticles. Biodegradable polyurethane nanocomposites having poly(caprolactone) oligomers as soft segments were obtained by delaminating clay particles within a polyurethane aqueous dispersion. The drug was incorporated into the polymer by dispersing it in the waterborne polyurethane followed by a drying step. Nanoparticles derived from clay were demonstrated to be able to tailor the mechanical properties of polyurethanes to achieve values that can match the properties of ocular soft tissues. Infrared spectra (FTIR) showed that the presence of clay particles was able to change the microphase separation process typical of polyurethanes. X-ray diffraction and small angle x-ray scattering (SAXS) results were explored to show that the incorporation of both dexamethasone acetate and nanocomponents derived from clay led to a less defined two-phase polyurethane. The presence of clay nanoparticles increased the rate of drug release measured in vitro. Human retinal pigment epithelial cells (ARPE-19) were cultured in contact with polyurethanes and polyurethane nanocomposites, and the viability of them (evaluated by using MTT assay after 7 days) showed that no toxic components were released from polyurethanes containing no drugs during the test.

[Biodegradability of the components of natural hydrocarbon mixtures previously submitted to landfarming].

Science.gov (United States)

Pucci, G N; Pucci, O H

2003-01-01

The complex composition of the crude oil and the hydrocarbons that integrate the waste of the different stages of the oil industry turn this product a mixture that presents different difficulties for its elimination by biological methods. The objective of this paper was to study the biodegradation potential of autochthonous bacterial communities on hydrocarbons obtained from four polluted places and subjected to landfarming biorremediation system during a decade. The results showed a marked difference in biodegradability of the three main fractions of crude oil, aliphatic, aromatic, and polar fractions, obtained by column chromatography. All fractions were used as carbon source and energy. There were variations in the production of biomass among the different fractions as well as in the kinetics of biodegradation, according to the composition of each fraction.

Enhancement of orimulsion biodegradation through the addition of natural marine carbon substrates

Energy Technology Data Exchange (ETDEWEB)

Proctor, L.M.; Toy, E.; Lapham, L.; Cherrier, J.; Chanton, J.P. [Florida State University, Tallahassee, FL (USA). Dept. of Oceanography

2001-04-01

Orimulsion is a bitumen-based heavy fuel that is a less expensive alternative to traditional fuel oils. However, because its density is intermediate between that of freshwater and seawater, in the event of a spill, the fuel could strand in the sediments. Previous work indicated that only 0.6 - 2.7% of the bitumen would degrade in long incubations of marine sediments. Various natural carbon substrates were added to stimulate the degradation of bitumen by native populations of benthic bacteria. The concentration and carbon isotopic signature of the respired carbon dioxide was measured to partition the substrates that supported bacterial respiration. It was found that the addition of seagrass and pinfish stimulated the degradation of bitumen by as much as 2 to 9-fold relative to incubations without these substrates. Biodegradation of bitumen may be enhanced by the addition of natural marine carbon substrates and may be a useful approach for bioremediation. Preadaption of the bacteria to bitumen did not significantly enhance their ability to degrade it. 13 refs., 5 figs., 2 tab.

Magnetic polymer nanospheres for anticancer drug targeting

Energy Technology Data Exchange (ETDEWEB)

JurIkova, A; Csach, K; Koneracka, M; Zavisova, V; Tomasovicova, N; Lancz, G; Kopcansky, P; Timko, M; Miskuf, J [Institute of Experimental Physics, Slovak Academy of Sciences, 040 01 Kosice (Slovakia); Muckova, M, E-mail: akasard@saske.s [Hameln rds a.s., 900 01 Modra (Slovakia)

2010-01-01

Poly(D,L-lactide-co-glycolide) polymer (PLGA) nanospheres loaded with biocom-patible magnetic fluid as a magnetic carrier and anticancer drug Taxol were prepared by the modified nanoprecipitation method with size of 200-250 nm in diameter. The PLGA polymer was utilized as a capsulation material due to its biodegradability and biocompatibility. Taxol as an important anticancer drug was chosen for its significant role against a wide range of tumours. Thermal properties of the drug-polymer system were characterized using thermal analysis methods. It was determined the solubility of Taxol in PLGA nanospheres. Magnetic properties investigated using SQUID magnetometry showed superparamagnetism of the prepared magnetic polymer nanospheres.

Evaluation of the influence of the use of waste from the processing of rice in physicochemical properties and biodegradability of PHB in composites

Directory of Open Access Journals (Sweden)

Ana Paula Wünsch Boitt

2014-12-01

Full Text Available The high calorific value of rice husks has elevated its reuse as an energy source; however, the burning of these shells generates a waste ash from rice husk ash (RHA, which makes its disposal a concern. Despite advances, biodegradable polymers are not yet able to compete with those of traditional thermoplastics, which have lower production cost and higher performance. Based on this background, this paper studies the feasibility of reuse of RHA as filler in polymer matrices replacing the conventional filler. This study consists of applying different percentages of RHA in the formulation of polyhydroxybutyrate composite (PHB and the use of talc (TA for comparison purposes as conventional filler. The composites used in this assay were obtained by twin-screw extrusion and injection molding of the polymer plus the fillers under study. Physicochemical and biodegradability properties of the composites were evaluated. The composite PHB/RHA was superior in the biodegradability tests and the properties remain practically unchanged in the presence of the filler. Thus, composites with RHA are promising because they take an abundant residue combined with degradation capacity of the polymer, therefore reducing cost and the environmental impact.

Nanofibers extraction from palm mesocarp fiber for biodegradable polymers incorporation

International Nuclear Information System (INIS)

Kuana, Vanessa A.; Rodrigues, Vanessa B.; Takahashi, Marcio C.; Campos, Adriana de; Sena Neto, Alfredo R.; Mattoso, Luiz H.C.; Marconcini, Jose M.

2015-01-01

The palm mesocarp fibers are residues produced by the palm oil industries. The objective of this paper is to determine an efficient treatment to extract crystal cellulose nanofibers from the palm mesocarp fibers to be incorporated in biodegradable polymeric composites. The fibers were saponified, bleached and analyzed with thermal gravimetric analysis, X-ray diffraction, Fourier transform infrared spectroscopy and scanning electron microscopy. (author)

Radiation synthesis and characterization of network structure of natural/synthetic double-network superabsorbent polymers

International Nuclear Information System (INIS)

Sen, M.; Hayrabolulu, H.

2011-01-01

Complete text of publication follows. Superabsorbent polymers (SAPs) are moderately cross linked, 3-D, hydrophilic network polymers that can absorb and conserve considerable amounts of aqueous fluids even under certain heat or pressure. Because of the unique properties superior to conventional absorbents, SAPs have found potential application in many fields such as hygienic products, disposable diapers, horticulture, gel actuators, drug-delivery systems, as well as water-blocking tapes coal dewatering, water managing materials for the renewal of arid and desert environment, etc. In recent years, naturally available resources, such as polysaccharides have drawn considerable attention for the preparation of SAPs. Since the mechanical properties of polysaccharide based natural polymers are low, researchers have mostly focused on natural/synthetic polymer/monomer mixtures to obtain novel SAPs. The aim of this study is to synthesize and characterization of network structure of novel double-network (DN) hydrogels as a SAP. Hydrogels with high mechanical strength have been prepared by radiation induced polymerization and crosslink of acrylic acid sodium salt in the presence of natural polymer locust bean gum. Liquid retention capacities and absorbency under load (AUL) analysis of synthesized SAPs was performed at different temperatures in water and synthetic urine solution, in order to determine their SAP character. For the characterization of network structure of the semi-IPN hydrogels, the average molecular weight between cross links (M c ) were evaluated by using uniaxial compression and oscillatory dynamical mechanical analyses and the advantage and disadvantage of these two technique for the characterization of network structures were compared.

Radiation processing of natural polymers for industrial and agricultural applications

International Nuclear Information System (INIS)

Hegazy, El-Sayed A.; AbdEl-Rehim, H.; Diaa, D.A.; El-Barbary, A.

2008-01-01

Radiation induced degradation technology is a new and promising application of ionizing radiation to develop viscose, pulp, paper, food preservation, pharmaceutical production, and natural bioactive agents industries. Controlling the degree of degradation, uniform molecular weight distribution, saving achieved in the chemicals (used in conventional methods) on a cost basis, and environmentally friendly process are the beneficial effects of using radiation technology in these industries. However, for some development countries such technology is not economic. Therefore, a great efforts should be done to reduce the cost required for such technologies. One of the principle factors for reducing the cost is achieving the degradation at low irradiation doses. The addition of some additives such as potassium per-sulfate (KPS), ammonium per-sulfate (APS), or H 2 O 2 to natural polymers (carboxymethylcellulose (CMC), chitosan, carrageenan and Na-alginate) during irradiation process accelerates their degradation. The highest degradation rate of polysaccharides obtained when APS was used. The end product of irradiated CMC, chitosan, carrageenan and Na-alginate may be used as food additive or benefited in agricultural purposes. On the other hand, radiation crosslinking of PAAm or PNIPAAm is affected by the presence of natural polymer like CMC-Na and carrageenan due to their degradability which could be controlled according to its concentration in the bulk medium and irradiation dose. Accordingly, the gel content, thermo-sensitivity (LCST) and swelling properties of PNIPAAm based natural polymers could be controlled. The swelling of the prepared copolymer hydrogels was investigated for its possible use in personal care articles particularly diapers or as carriers for drug delivery systems. The prepared crosslinked copolymers possessed high and fast swelling properties in simulated urine media and the swelling ratios of CMC-Na/PAAm gels in urine are acceptable for diaper

Biodegradation of Polypropylene Nonwovens