WorldWideScience

Sample records for biopolymers

  1. Lignin biopolymer based triboelectric nanogenerators

    Science.gov (United States)

    Bao, Yukai; Wang, Ruoxing; Lu, Yunmei; Wu, Wenzhuo

    2017-07-01

    Ongoing research in triboelectric nanogenerators (TENGs) focuses on increasing power generation, but obstacles concerning economical and eco-friendly utilization of TENGs continue to prevail. Being the second most abundant biopolymer on earth, lignin offers a valuable opportunity for low-cost TENG applications in biomedical devices, benefitting from its biodegradability and biocompatibility. Here, we develop for the first time a lignin biopolymer based TENGs for harvesting mechanical energy in the environment, which shows great potential for self-powered biomedical devices among other applications and opens doors to new technologies that utilize otherwise wasted materials for economically feasible and ecologically friendly production of energy devices.

  2. Nanostructure features of microalgae biopolymer

    Czech Academy of Sciences Publication Activity Database

    Cybulska, J.; Halaj, M.; Cepák, Vladislav; Lukavský, Jaromír; Capek, P.

    2016-01-01

    Roč. 68, 7-8 (2016), s. 629-636 ISSN 0038-9056 R&D Projects: GA TA ČR TE01020080; GA TA ČR TA03011027 Institutional support: RVO:67985939 Keywords : Dictyosphaerium * biopolymers * alga Subject RIV: CD - Macromolecular Chemistry Impact factor: 1.837, year: 2016

  3. Biocompatibility of plasma nanostructured biopolymers

    Czech Academy of Sciences Publication Activity Database

    Kasálková-Slepičková, N.; Slepička, P.; Bačáková, Lucie; Sajdl, P.; Švorčík, V.

    2013-01-01

    Roč. 307, Jul 15 (2013), s. 642-646 ISSN 0168-583X R&D Projects: GA ČR(CZ) GBP108/12/G108 Institutional support: RVO:67985823 Keywords : biopolymer * plasma treatment * biocompatibility Subject RIV: JJ - Other Materials Impact factor: 1.186, year: 2013

  4. Biopolymer chitin: extraction and characterization

    International Nuclear Information System (INIS)

    Andrade, Sania M.B. de; Ladchumananandasivam, Rasiah

    2011-01-01

    The biopolymers are materials made from renewable sources such as soybean, corn, cane sugar, cellulose and chitin. Chitin is the most abundant biopolymer found in nature, after cellulose. The chemical structure of chitin is distinguished by the hydroxyl group, of structure from cellulose, located at position C-2, which in the chitin is replaced by acetamine group. The objective of this study was to develop the chitin from exoskeletons of Litopenaeus vannamei shrimp, which are discarded as waste, causing pollutions, environmental problems and thus obtain better utilization of these raw materials. It also, show the extraction process and deacetylation of chitosan. The extraction of chitin followed steps of demineralization, desproteinization and deodorization. Chitin and chitosan were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) and the thermals properties were analyzed by thermogravimetry (TG/DTG). (author)

  5. Electrogelation of Biopolymers for New Functional Materials

    Science.gov (United States)

    2013-08-31

    TERMS silk , materials, electrogelation, egeJ.. biopolymers , tropoelastin 1.8. SECURITY CLASSIFICATION OF: 17. UMITATION OF a. REPORT b. ABSTRACT c...additional biopolymers with utility to exploit the egel process. We have focused on the silk and tropoelastin systems due to our ability to genetically...of Biopolymers for New Functional Materials 5b. GRANT NUMBER FA9550-10-1-0172 Sc. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT NUMBER Kaplan

  6. Simulations of biopolymer networks under shear

    NARCIS (Netherlands)

    Huisman, Elisabeth Margaretha

    2011-01-01

    In this thesis we present a new method to simulate realistic three-dimensional networks of biopolymers under shear. These biopolymer networks are important for the structural functions of cells and tissues. We use the method to analyze these networks under shear, and consider the elastic modulus,

  7. Autonomous valve for detection of biopolymer degradation

    DEFF Research Database (Denmark)

    Keller, Stephan Urs; Noeth, Nadine-Nicole; Fetz, Stefanie

    2009-01-01

    We present a polymer microvalve that allows the detection of biopolymer degradation without the need of external energy. The valve is based on a polymer container filled with a colored marker solution and closed by a thin lid. This structure is covered by a film of poly(L-lactide) and degradation...... of the biopolymer triggers the release of the color which is detected visually. The autonomous valve has potential for the fast testing of biopolymer degradation under various environmental conditions or by specific enzymes....

  8. Green synthesis of silver nanoparticles and biopolymer ...

    Indian Academy of Sciences (India)

    2018-03-29

    Mar 29, 2018 ... Keywords. Biogenic silver nanoparticles; biopolymer nanocomposites; nanoparticles stability; ... Production of nanomaterials by using living organisms of plant-based ... 2.1b Microorganisms and cell culture: The evaluation of.

  9. System for measuring radioactivity of labelled biopolymers

    International Nuclear Information System (INIS)

    Gross, V.

    1980-01-01

    A system is described for measuring radioactivity of labelled biopolymers, comprising: a set of containers adapted for receiving aqueous solutions of biological samples containing biopolymers which are subsequently precipitated in said containers on particles of diatomite in the presence of a coprecipitator, then filtered, dissolved, and mixed with a scintillator; radioactivity measuring means including a detection chamber to which is fed the mixture produced in said set of containers; an electric drive for moving said set of containers in a stepwise manner; means for proportional feeding of said coprecipitator and a suspension of diatomite in an acid solution to said containers which contain the biological sample for forming an acid precipitation of biopolymers; means for the removal of precipitated samples from said containers; precipitated biopolymer filtering means for successively filtering the precipitate, suspending the precipitate, dissolving the biopolymers mixed with said scintillator for feeding of the mixture to said detection chamber; a system of pipelines interconnecting said above-recited means; and said means for measuring radioactivity of labelled biopolymers including, a measuring cell arranged in a detection chamber and communicating with said means for filtering precipitated biopolymers through one pipeline of said system of pipelines; a program unit electrically connected to said electric drive, said means for acid precipatation of biopolymers, said means for the removal of precipitated samples from said containers, said filtering means, and said radioactivity measuring device; said program unit adapted to periodically switch on and off the above-recited means and check the sequence of the radioactivity measuring operations; and a control unit for controlling the initiation of the system and for selecting programs

  10. Invited review nonmulberry silk biopolymers.

    Science.gov (United States)

    Kundu, S C; Kundu, Banani; Talukdar, Sarmistha; Bano, Subia; Nayak, Sunita; Kundu, Joydip; Mandal, Biman B; Bhardwaj, Nandana; Botlagunta, Mahendran; Dash, Biraja C; Acharya, Chitrangada; Ghosh, Ananta K

    2012-06-01

    The silk produced by silkworms are biopolymers and can be classified into two types--mulberry and nonmulberry. Mulberry silk of silkworm Bombyx mori has been extensively explored and used for century old textiles and sutures. But for the last few decades it is being extensively exploited for biomedical applications. However, the transformation of nonmulberry silk from being a textile commodity to biomaterials is relatively new. Within a very short period of time, the combination of load bearing capability and tensile strength of nonmulberry silk has been equally envisioned for bone, cartilage, adipose, and other tissue regeneration. Adding to its advantage is its diverse morphology, including macro to nano architectures with controllable degradation and biocompatibility yields novel natural material systems in vitro. Its follow on applications involve sustained release of model compounds and anticancer drugs. Its 3D cancer models provide compatible microenvironment systems for better understanding of the cancer progression mechanism and screening of anticancer compounds. Diversely designed nonmulberry matrices thus provide an array of new cutting age technologies, which is unattainable with the current synthetic materials that lack biodegradability and biocompatibility. Scientific exploration of nonmulberry silk in tissue engineering, regenerative medicine, and biotechnological applications promises advancement of sericulture industries in India and China, largest nonmulberry silk producers of the world. This review discusses the prospective biomedical applications of nonmulberry silk proteins as natural biomaterials. Copyright © 2012 Wiley Periodicals, Inc.

  11. Investigation on wear characteristic of biopolymer gear

    Science.gov (United States)

    Ghazali, Wafiuddin Bin Md; Daing Idris, Daing Mohamad Nafiz Bin; Sofian, Azizul Helmi Bin; Basrawi, Mohamad Firdaus bin; Khalil Ibrahim, Thamir

    2017-10-01

    Polymer is widely used in many mechanical components such as gear. With the world going to a more green and sustainable environment, polymers which are bio based are being recognized as a replacement for conventional polymers based on fossil fuel. The use of biopolymer in mechanical components especially gear have not been fully explored yet. This research focuses on biopolymer for spur gear and whether the conventional method to investigate wear characteristic is applicable. The spur gears are produced by injection moulding and tested on several speeds using a custom test equipment. The wear formation such as tooth fracture, tooth deformation, debris and weight loss was observed on the biopolymer spur gear. It was noted that the biopolymer gear wear mechanism was similar with other type of polymer spur gears. It also undergoes stages of wear which are; running in, linear and rapid. It can be said that the wear mechanism of biopolymer spur gear is comparable to fossil fuel based polymer spur gear, thus it can be considered to replace polymer gears in suitable applications.

  12. Carboxymethyl Carrageenan Based Biopolymer Electrolytes

    International Nuclear Information System (INIS)

    Mobarak, N.N.; Jumaah, F.N.; Ghani, M.A.; Abdullah, M.P.; Ahmad, A.

    2015-01-01

    data, which demonstrated that the ionic conductivity of the 20 wt.% LiNO 3 iota-based electrolytes was highly similar with the 30 wt.% LiNO 3 kappa-based electrolytes, with values of 5.85 × 10 −3 S cm −1 and 5.51 × 10 −3 S cm −1 , respectively. The lithium transference number for the carboxymethyl kappa carrageenan was higher than for the carboxymethyl iota carrageenan. Additionally, the carboxymethyl iota carrageenan and carboxymethyl kappa carrageenan films were electrochemically stable up to ∼3.0 and 3.1 V, respectively, which indicates that these solid biopolymer electrolytes are promising candidates for utilization in electrochemical devices

  13. Fabrication of biopolymer cantilevers using nanoimprint lithography

    DEFF Research Database (Denmark)

    Keller, Stephan Sylvest; Feidenhans'l, Nikolaj Agentoft; Fisker-Bødker, Nis

    2011-01-01

    The biodegradable polymer poly(l-lactide) (PLLA) was introduced for the fabrication of micromechanical devices. For this purpose, thin biopolymer films with thickness around 10 μm were spin-coated on silicon substrates. Patterning of microcantilevers is achieved by nanoimprint lithography. A major...... challenge was the high adhesion between PLLA and silicon stamp. Optimized stamp fabrication and the deposition of a 125 nm thick fluorocarbon anti-stiction coating on the PLLA allowed the fabrication of biopolymer cantilevers. Resonance frequency measurements were used to estimate the Young’s modulus...

  14. Biopolymer colloids for controlling and templating inorganic synthesis

    Directory of Open Access Journals (Sweden)

    Laura C. Preiss

    2014-11-01

    Full Text Available Biopolymers and biopolymer colloids can act as controlling agents and templates not only in many processes in nature, but also in a wide range of synthetic approaches. Inorganic materials can be either synthesized ex situ and later incorporated into a biopolymer structuring matrix or grown in situ in the presence of biopolymers. In this review, we focus mainly on the latter case and distinguish between the following possibilities: (i biopolymers as controlling agents of nucleation and growth of inorganic materials; (ii biopolymers as supports, either as molecular supports or as carrier particles acting as cores of core–shell structures; and (iii so-called “soft templates”, which include on one hand stabilized droplets, micelles, and vesicles, and on the other hand continuous scaffolds generated by gelling biopolymers.

  15. Rheology of Biopolymer Solutions and Gels

    Directory of Open Access Journals (Sweden)

    David R. Picout

    2003-01-01

    Full Text Available Rheological techniques and methods have been employed for many decades in the characterization of polymers. Originally developed and used on synthetic polymers, rheology has then found much interest in the field of natural (bio polymers. This review concentrates on introducing the fundamentals of rheology and on discussing the rheological aspects and properties of the two major classes of biopolymers: polysaccharides and proteins. An overview of both their solution properties (dilute to semi-dilute and gel properties is described.

  16. Bioflocculation of Basic Dye onto Isolated Microbial Biopolymers

    Directory of Open Access Journals (Sweden)

    M. Elkady

    2017-10-01

    Full Text Available Three purified biopolymers isolated from Bacillus velezensis (40B, Bacillus mojavensis (32A and Pseudomonas (38A strains were evaluated for dye decolourization as bioflocculants. The decolourization capacity of the three polymers was inspected using C.I 28 basic yellow dye as hazardous pollutant. The chemical compositions of these purified biopolymers were considered by HPLC and FTIR spectrum. The decolourization efficiency of the three purified biopolymers was determined using both real dye polluted wastewater (discharged from AKSA EGYPT acrylic fibres industry and simulated synthetic wastewater. The maximum decolourization efficiencies of the purified biopolymers of the three studied strains (40B, (32A and (38A were 91, 89 and 88 %, respectively. The equilibrium of dye sorption process onto biopolymers was described using Langmuir isotherm equation. However, its kinetics follows the pseudo second order model. The thermodynamic examination investigated the exothermic and spontaneous nature of the decolourization process using the purified biopolymers.

  17. Sustainably Sourced, Thermally Resistant, Radiation Hard Biopolymer

    Science.gov (United States)

    Pugel, Diane

    2011-01-01

    This material represents a breakthrough in the production, manufacturing, and application of thermal protection system (TPS) materials and radiation shielding, as this represents the first effort to develop a non-metallic, non-ceramic, biomaterial-based, sustainable TPS with the capability to also act as radiation shielding. Until now, the standing philosophy for radiation shielding involved carrying the shielding at liftoff or utilizing onboard water sources. This shielding material could be grown onboard and applied as needed prior to different radiation landscapes (commonly seen during missions involving gravitational assists). The material is a bioplastic material. Bioplastics are any combination of a biopolymer and a plasticizer. In this case, the biopolymer is a starch-based material and a commonly accessible plasticizer. Starch molecules are composed of two major polymers: amylase and amylopectin. The biopolymer phenolic compounds are common to the ablative thermal protection system family of materials. With similar constituents come similar chemical ablation processes, with the potential to have comparable, if not better, ablation characteristics. It can also be used as a flame-resistant barrier for commercial applications in buildings, homes, cars, and heater firewall material. The biopolymer is observed to undergo chemical transformations (oxidative and structural degradation) at radiation doses that are 1,000 times the maximum dose of an unmanned mission (10-25 Mrad), indicating that it would be a viable candidate for robust radiation shielding. As a comparison, the total integrated radiation dose for a three-year manned mission to Mars is 0.1 krad, far below the radiation limit at which starch molecules degrade. For electron radiation, the biopolymer starches show minimal deterioration when exposed to energies greater than 180 keV. This flame-resistant, thermal-insulating material is non-hazardous and may be sustainably sourced. It poses no hazardous

  18. Significance of collective motions in biopolymers and neutron scattering

    Energy Technology Data Exchange (ETDEWEB)

    Go, Nobuhiro [Kyoto Univ. (Japan)

    1996-05-01

    Importance of collective variable description of conformational dynamics of biopolymers and the vital role that neutron inelastic scattering phenomena would play in its experimental determination are discussed. (author)

  19. Effective Energy Methods for Global Optimization for Biopolymer Structure Prediction

    National Research Council Canada - National Science Library

    Shalloway, David

    1998-01-01

    .... Its main strength is that it uncovers and exploits the intrinsic "hidden structures" of biopolymer energy landscapes to efficiently perform global minimization using a hierarchical search procedure...

  20. Biopolymers and its aplication on environment

    Directory of Open Access Journals (Sweden)

    Sonia Ospina

    2015-07-01

    Full Text Available The use of disposable packaging has made the world million tons of non-biodegradable waste generated . For many years we used non-biodegradable , petroleum plastic packaging . Belatedly we have realized that to continue this rate of contamination, soon ocasionaremos irreparable damage to the environment . It is therefore all efforts on seeking alternatives to the use of non-biodegradable packaging, are of great importance , in order to restore the damaged environment so far, and prevent deterioration onwards. In this regard , research in different areas of biotechnology has allowed the production of biodegradable packaging produced from microbial biopolymers.

  1. Proton conduction in biopolymer exopolysaccharide succinoglycan

    Energy Technology Data Exchange (ETDEWEB)

    Kweon, Jin Jung [Department of Physics, Korea University, Seoul 136-713 (Korea, Republic of); National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32310 (United States); Lee, Kyu Won; Kim, Hyojung; Lee, Cheol Eui, E-mail: rscel@korea.ac.kr [Department of Physics, Korea University, Seoul 136-713 (Korea, Republic of); Jung, Seunho [Department of Bioscience and Biotechnology and UBITA, Konkuk University, Seoul 143-701 (Korea, Republic of); Kwon, Chanho [Naraebio Research Laboratories, 177 Dangha-ri, Bongdam-eup, Hawseong-si 445-892 (Korea, Republic of)

    2014-07-07

    Protonic currents play a vital role in electrical signalling in living systems. It has been suggested that succinoglycan plays a specific role in alfalfa root nodule development, presumably acting as the signaling molecules. In this regard, charge transport and proton dynamics in the biopolymer exopolysaccharide succinoglycan have been studied by means of electrical measurements and nuclear magnetic resonance (NMR) spectroscopy. In particular, a dielectric dispersion in the system has revealed that the electrical conduction is protonic rather electronic. Besides, our laboratory- and rotating-frame {sup 1}H NMR measurements have elucidated the nature of the protonic conduction, activation of the protonic motion being associated with a glass transition.

  2. Biopolymer based nanocomposites reinforced with graphene nanoplatelets

    Energy Technology Data Exchange (ETDEWEB)

    Botta, L.; Scaffaro, R.; Mistretta, M. C.; La Mantia, F. P. [Dipartimento di Ingegneria Civile, Ambientale, Aerospaziale, dei Materiali, Università di Palermo, UdR INSTM di Palermo, Viale delle Scienze, 90128 Palermo (Italy)

    2016-05-18

    In this work, biopolymer based nanocomposites filled with graphene nanoplatelets (GnP) were prepared by melt compounding in a batch mixer. The polymer used as matrix was a commercial biodegradable polymer-blend of PLA and a copolyester (BioFlex®). The prepared materials were characterized by scanning electron microscopy (SEM), rheological and mechanical measurements. Moreover, the effect of the GnP amount on the investigated properties was evaluated. The results indicated that the incorporation of GnP increased the stiffness of the biopolymeric matrix.

  3. Moisture sorption in mixtures of biopolymer, disaccharides and water

    NARCIS (Netherlands)

    Sman, van der R.G.M.

    2013-01-01

    The moisture sorption of ternary mixtures of biopolymer, sugar and water is investigated by means of the Free-Volume-Flory-Huggins (FVFH) theory. The earlier FVFH theory developed for binary mixtures of biopolymer/water and sugar/water has to be modified to account for two effects: 1) the change in

  4. 3D-Printed Biopolymers for Tissue Engineering Application

    Directory of Open Access Journals (Sweden)

    Xiaoming Li

    2014-01-01

    Full Text Available 3D printing technology has recently gained substantial interest for potential applications in tissue engineering due to the ability of making a three-dimensional object of virtually any shape from a digital model. 3D-printed biopolymers, which combine the 3D printing technology and biopolymers, have shown great potential in tissue engineering applications and are receiving significant attention, which has resulted in the development of numerous research programs regarding the material systems which are available for 3D printing. This review focuses on recent advances in the development of biopolymer materials, including natural biopolymer-based materials and synthetic biopolymer-based materials prepared using 3D printing technology, and some future challenges and applications of this technology are discussed.

  5. Achieving biopolymer synergy in systems chemistry.

    Science.gov (United States)

    Bai, Yushi; Chotera, Agata; Taran, Olga; Liang, Chen; Ashkenasy, Gonen; Lynn, David G

    2018-05-31

    Synthetic and materials chemistry initiatives have enabled the translation of the macromolecular functions of biology into synthetic frameworks. These explorations into alternative chemistries of life attempt to capture the versatile functionality and adaptability of biopolymers in new orthogonal scaffolds. Information storage and transfer, however, so beautifully represented in the central dogma of biology, require multiple components functioning synergistically. Over a single decade, the emerging field of systems chemistry has begun to catalyze the construction of mutualistic biopolymer networks, and this review begins with the foundational small-molecule-based dynamic chemical networks and peptide amyloid-based dynamic physical networks on which this effort builds. The approach both contextualizes the versatile approaches that have been developed to enrich chemical information in synthetic networks and highlights the properties of amyloids as potential alternative genetic elements. The successful integration of both chemical and physical networks through β-sheet assisted replication processes further informs the synergistic potential of these networks. Inspired by the cooperative synergies of nucleic acids and proteins in biology, synthetic nucleic-acid-peptide chimeras are now being explored to extend their informational content. With our growing range of synthetic capabilities, structural analyses, and simulation technologies, this foundation is radically extending the structural space that might cross the Darwinian threshold for the origins of life as well as creating an array of alternative systems capable of achieving the progressive growth of novel informational materials.

  6. Bacillus and biopolymer: Prospects and challenges

    Directory of Open Access Journals (Sweden)

    Swati Mohapatra

    2017-12-01

    Full Text Available The microbially derived polyhydroxyalkanoates biopolymers could impact the global climate scenario by replacing the conventional non-degradable, petrochemical-based polymer. The biogenesis, characterization and properties of PHAs by Bacillus species using renewable substrates have been elaborated by many for their wide applications. On the other hand Bacillus species are advantageous over other bacteria due to their abundance even in extreme ecological conditions, higher growth rates even on cheap substrates, higher PHAs production ability, and the ease of extracting the PHAs. Bacillus species possess hydrolytic enzymes that can be exploited for economical PHAs production. This review summarizes the recent trends in both non-growth and growth associated PHAs production by Bacillus species which may provide direction leading to future research towards this growing quest for biodegradable plastics, one more critical step ahead towards sustainable development.

  7. Constitutive modelling of composite biopolymer networks.

    Science.gov (United States)

    Fallqvist, B; Kroon, M

    2016-04-21

    The mechanical behaviour of biopolymer networks is to a large extent determined at a microstructural level where the characteristics of individual filaments and the interactions between them determine the response at a macroscopic level. Phenomena such as viscoelasticity and strain-hardening followed by strain-softening are observed experimentally in these networks, often due to microstructural changes (such as filament sliding, rupture and cross-link debonding). Further, composite structures can also be formed with vastly different mechanical properties as compared to the individual networks. In this present paper, we present a constitutive model presented in a continuum framework aimed at capturing these effects. Special care is taken to formulate thermodynamically consistent evolution laws for dissipative effects. This model, incorporating possible anisotropic network properties, is based on a strain energy function, split into an isochoric and a volumetric part. Generalisation to three dimensions is performed by numerical integration over the unit sphere. Model predictions indicate that the constitutive model is well able to predict the elastic and viscoelastic response of biological networks, and to an extent also composite structures. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. Customizable Biopolymers for Heavy Metal Remediation

    International Nuclear Information System (INIS)

    Kostal, Jan; Prabhukumar, Giridhar; Lao, U. Loi; Chen Alin; Matsumoto, Mark; Mulchandani, Ashok; Chen, Wilfred

    2005-01-01

    Nanoscale materials have been gaining increasing interest in the area of environmental remediation because of their unique physical, chemical and biological properties. One emerging area of research has been the development of novel materials with increased affinity, capacity, and selectivity for heavy metals because conventional technologies are often inadequate to reduce concentrations in wastewater to acceptable regulatory standards. Genetic and protein engineering have emerged as the latest tools for the construction of nanoscale materials that can be controlled precisely at the molecular level. With the advent of recombinant DNA techniques, it is now possible to create 'artificial' protein polymers with fundamentally new molecular organization. The most significant feature of these nanoscale biopolymers is that they are specifically pre-programmed within a synthetic gene template and can be controlled precisely in terms of sizes, compositions and functions at the molecular level. In this review, the use of specifically designed protein-based nano-biomaterials with both metal-binding and tunable properties for heavy metal removal is summarized. Several different strategies for the selective removal of heavy metals such as cadmium and mercury are highlighted

  9. Viscoplastic fracture transition of a biopolymer gel.

    Science.gov (United States)

    Frieberg, Bradley R; Garatsa, Ray-Shimry; Jones, Ronald L; Bachert, John O; Crawshaw, Benjamin; Liu, X Michael; Chan, Edwin P

    2018-06-13

    Physical gels are swollen polymer networks consisting of transient crosslink junctions associated with hydrogen or ionic bonds. Unlike covalently crosslinked gels, these physical crosslinks are reversible thus enabling these materials to display highly tunable and dynamic mechanical properties. In this work, we study the polymer composition effects on the fracture behavior of a gelatin gel, which is a thermoreversible biopolymer gel consisting of denatured collagen chains bridging physical network junctions formed from triple helices. Below the critical volume fraction for chain entanglement, which we confirm via neutron scattering measurements, we find that the fracture behavior is consistent with a viscoplastic type process characterized by hydrodynamic friction of individual polymer chains through the polymer mesh to show that the enhancement in fracture scales inversely with the squared of the mesh size of the gelatin gel network. Above this critical volume fraction, the fracture process can be described by the Lake-Thomas theory that considers fracture as a chain scission process due to chain entanglements.

  10. Proton Conductivity Studies on Biopolymer Electrolytes

    International Nuclear Information System (INIS)

    Harun, N. I.; Sabri, N. S.; Rosli, N. H. A.; Taib, M. F. M.; Saaid, S. I. Y.; Kudin, T. I. T.; Ali, A. M. M.; Yahya, M. Z. A.

    2010-01-01

    Proton conducting solid biopolymer electrolyte membranes consisting of methyl cellulose (MC) and different wt.% of ammonium nitrate (NH 4 NO 3 ) were prepared by solution cast technique. Impedance spectroscopy was carried out to study electrical characteristics of bulk materials. The ionic conductivity of the prepared samples was calculated using the bulk resistance (R b ) obtained from impedance spectroscopy plot. The highest ionic conductivity obtained was 1.17x10 -4 Scm -1 for the sample with composition ratio of MC(50): NH 4 NO 3 (50). To enhance the ionic conductivity, propylene carbonate (PC) and ethylene carbonate (EC) plasticizers were introduced. It was found that the ionic conductivity of polymer electrolyte membranes increased with the increase in plasticizers concentration. The ionic conductivities of solid polymer electrolytes based on MC-NH 4 NO 3 -PC was enhanced up to 4.91x10 -3 Scm -1 while for the MC-NH 4 NO 3 -EC system, the highest conductivity was 1.74x10 -2 Scm -1 . The addition of more plasticizer however decreases in mechanical stability of the membranes.

  11. Equilibrium & Nonequilibrium Fluctuation Effects in Biopolymer Networks

    Science.gov (United States)

    Kachan, Devin Michael

    Fluctuation-induced interactions are an important organizing principle in a variety of soft matter systems. In this dissertation, I explore the role of both thermal and active fluctuations within cross-linked polymer networks. The systems I study are in large part inspired by the amazing physics found within the cytoskeleton of eukaryotic cells. I first predict and verify the existence of a thermal Casimir force between cross-linkers bound to a semi-flexible polymer. The calculation is complicated by the appearance of second order derivatives in the bending Hamiltonian for such polymers, which requires a careful evaluation of the the path integral formulation of the partition function in order to arrive at the physically correct continuum limit and properly address ultraviolet divergences. I find that cross linkers interact along a filament with an attractive logarithmic potential proportional to thermal energy. The proportionality constant depends on whether and how the cross linkers constrain the relative angle between the two filaments to which they are bound. The interaction has important implications for the synthesis of biopolymer bundles within cells. I model the cross-linkers as existing in two phases: bound to the bundle and free in solution. When the cross-linkers are bound, they behave as a one-dimensional gas of particles interacting with the Casimir force, while the free phase is a simple ideal gas. Demanding equilibrium between the two phases, I find a discontinuous transition between a sparsely and a densely bound bundle. This discontinuous condensation transition induced by the long-ranged nature of the Casimir interaction allows for a similarly abrupt structural transition in semiflexible filament networks between a low cross linker density isotropic phase and a higher cross link density bundle network. This work is supported by the results of finite element Brownian dynamics simulations of semiflexible filaments and transient cross-linkers. I

  12. Biopolymers for sample collection, protection, and preservation.

    Science.gov (United States)

    Sorokulova, Iryna; Olsen, Eric; Vodyanoy, Vitaly

    2015-07-01

    One of the principal challenges in the collection of biological samples from air, water, and soil matrices is that the target agents are not stable enough to be transferred from the collection point to the laboratory of choice without experiencing significant degradation and loss of viability. At present, there is no method to transport biological samples over considerable distances safely, efficiently, and cost-effectively without the use of ice or refrigeration. Current techniques of protection and preservation of biological materials have serious drawbacks. Many known techniques of preservation cause structural damages, so that biological materials lose their structural integrity and viability. We review applications of a novel bacterial preservation process, which is nontoxic and water soluble and allows for the storage of samples without refrigeration. The method is capable of protecting the biological sample from the effects of environment for extended periods of time and then allows for the easy release of these collected biological materials from the protective medium without structural or DNA damage. Strategies for sample collection, preservation, and shipment of bacterial, viral samples are described. The water-soluble polymer is used to immobilize the biological material by replacing the water molecules within the sample with molecules of the biopolymer. The cured polymer results in a solid protective film that is stable to many organic solvents, but quickly removed by the application of the water-based solution. The process of immobilization does not require the use of any additives, accelerators, or plastifiers and does not involve high temperature or radiation to promote polymerization.

  13. Obtention of gelatin biopolymers by ionizing radiation

    International Nuclear Information System (INIS)

    Takinami, Patricia Yoko Inamura

    2014-01-01

    The gelatin (Gel) is a biocompatible and biodegradable biopolymer, which naturally forms semi-solid colloids or hydrogels in aqueous solutions. As a hydrophilic polymer, the Gel has structural and physico-mechanical properties that distinguish it from synthetic hydrophilic polymers. The study of these properties led to the development of the present work. Thus, Gel-based films and hydrogels were developed using ionizing radiation technology by different techniques: irradiation with 60 Co, electron beam (EB) and/or pulsed EB. The Gel based-films enriched with different additives, such as glycerol (GLY), polyvinyl alcohol (PVA), butylated hydroxytoluene (BHT), acrylamide and/or vegetal fiber, were irradiated with doses from 10 to 60 kGy, depending on the additive; some parameters like mechanical properties, color, and water absorption were analyzed. In the radio-induced synthesis of GEL nanohydrogels, polyethylene glycol (PEG) and the mixture (MIX) of additives, PEG and GEL, the size, molar mass and surface morphology of the nanohydrogels were analyzed. There was a significant increase of gel fraction with increase of the radiation dose for the GEL/fiber samples. The GEL based-films with 10% PVA irradiated at 20 kGy showed the highest puncture strength. The addition of antioxidant BHT affected on some GEL based-films properties on applied conditions. Regarding the nanohydrogels, there was a decrease of hydrodynamic radius of MIX irradiated with 60 Co from 68 ± 25 nm (2 kGy) to 35 ± 4 nm (5 kGy). The radiation proved to be a convenient tool in the modification of polymeric materials for both, GEL films and hydrogels. (author)

  14. Optically controlled multiple switching operations of DNA biopolymer devices

    International Nuclear Information System (INIS)

    Hung, Chao-You; Tu, Waan-Ting; Lin, Yi-Tzu; Fruk, Ljiljana; Hung, Yu-Chueh

    2015-01-01

    We present optically tunable operations of deoxyribonucleic acid (DNA) biopolymer devices, where a single high-resistance state, write-once read-many-times memory state, write-read-erase memory state, and single low-resistance state can be achieved by controlling UV irradiation time. The device is a simple sandwich structure with a spin-coated DNA biopolymer layer sandwiched by two electrodes. Upon irradiation, the electrical properties of the device are adjusted owing to a phototriggered synthesis of silver nanoparticles in DNA biopolymer, giving rise to multiple switching scenarios. This technique, distinct from the strategy of doping of pre-formed nanoparticles, enables a post-film fabrication process for achieving optically controlled memory device operations, which provides a more versatile platform to fabricate organic memory and optoelectronic devices

  15. Optically controlled multiple switching operations of DNA biopolymer devices

    Energy Technology Data Exchange (ETDEWEB)

    Hung, Chao-You; Tu, Waan-Ting; Lin, Yi-Tzu [Institute of Photonics Technologies, National Tsing Hua University, Hsinchu 30013, Taiwan (China); Fruk, Ljiljana [Department of Chemical Engineering and Biotechnology, University of Cambridge, Pembroke Street, Cambridge CB2 3RA (United Kingdom); Hung, Yu-Chueh, E-mail: ychung@ee.nthu.edu.tw [Institute of Photonics Technologies, National Tsing Hua University, Hsinchu 30013, Taiwan (China); Department of Electrical Engineering, National Tsing Hua University, Hsinchu 30013, Taiwan (China)

    2015-12-21

    We present optically tunable operations of deoxyribonucleic acid (DNA) biopolymer devices, where a single high-resistance state, write-once read-many-times memory state, write-read-erase memory state, and single low-resistance state can be achieved by controlling UV irradiation time. The device is a simple sandwich structure with a spin-coated DNA biopolymer layer sandwiched by two electrodes. Upon irradiation, the electrical properties of the device are adjusted owing to a phototriggered synthesis of silver nanoparticles in DNA biopolymer, giving rise to multiple switching scenarios. This technique, distinct from the strategy of doping of pre-formed nanoparticles, enables a post-film fabrication process for achieving optically controlled memory device operations, which provides a more versatile platform to fabricate organic memory and optoelectronic devices.

  16. The surface properties of biopolymer-coated fruit: A review

    Directory of Open Access Journals (Sweden)

    Diana Cristina Moncayo Martinez

    2013-09-01

    Full Text Available Environmental conservation concerns have led to research and development regarding biodegradable materials from biopolymers, leading to new formulations for edible films and coatings for preserving the quality of fresh fruit and vegetables. Determining fruit skin surface properties for a given coating solution has led to predicting coating efficiency. Wetting was studied by considering spreading, adhesion and cohesion and measuring the contact angle, thus optimising the coating formulation in terms of biopolymer, plasticiser, surfactant, antimicrobial and antioxidant concentration. This work reviews the equations for determining fruit surface properties by using polar and dispersive interaction calculations and by determining the contact angle.

  17. Liquid crystalline biopolymers: A new arena for liquid crystal research

    International Nuclear Information System (INIS)

    Rizvi, Tasneem Zahra

    2001-07-01

    This paper gives a brief introduction to liquid crystals on the basis of biopolymers and reviews literature on liquid crystalline behaviour of biopolymers both in vitro and in vivo in relation to their implications in the fields of biology, medicine and material science. Knowledge in the field of biological liquid crystals is crucial for understanding complex phenomena at supramolecular level which will give information about processes involved in biological organization and function. The understanding of the interaction of theses crystals with electric, magnetic, optical and thermal fields will uncover mechanisms of near quantum-energy detection capabilities of biosystems

  18. Micromechanical sensors for the measurement of biopolymer degradation

    DEFF Research Database (Denmark)

    Keller, Stephan Sylvest; Gammelgaard, Lene; Jensen, M P

    2011-01-01

    We present microcantilever-based sensors for the characterization of biopolymer degradation by enzymes. Thin films of Poly(L-lactide) (PLLA) were spray-coated onto SU-8 cantilevers with well-known material properties and dimensions. The micromechanical sensors were immersed in solutions of protei......We present microcantilever-based sensors for the characterization of biopolymer degradation by enzymes. Thin films of Poly(L-lactide) (PLLA) were spray-coated onto SU-8 cantilevers with well-known material properties and dimensions. The micromechanical sensors were immersed in solutions...

  19. Models of the solvent-accessible surface of biopolymers

    Energy Technology Data Exchange (ETDEWEB)

    Smith, R.E.

    1996-09-01

    Many biopolymers such as proteins, DNA, and RNA have been studied because they have important biomedical roles and may be good targets for therapeutic action in treating diseases. This report describes how plastic models of the solvent-accessible surface of biopolymers were made. Computer files containing sets of triangles were calculated, then used on a stereolithography machine to make the models. Small (2 in.) models were made to test whether the computer calculations were done correctly. Also, files of the type (.stl) required by any ISO 9001 rapid prototyping machine were written onto a CD-ROM for distribution to American companies.

  20. Dispersability of Carbon Nanotubes in Biopolymer-Based Fluids

    Directory of Open Access Journals (Sweden)

    Franco Tardani

    2015-01-01

    Full Text Available In this review the dispersability of carbon nanotubes in aqueous solutions containing proteins, or nucleic acids, is discussed. Data reported previously are complemented by unpublished ones. In the mentioned nanotube-based systems several different phases are observed, depending on the type and concentration of biopolymer, as well as the amount of dispersed nanotubes. The phase behavior depends on how much biopolymers are adsorbing, and, naturally, on the molecular details of the adsorbents. Proper modulation of nanotube/biopolymer interactions helps switching between repulsive and attractive regimes. Dispersion or phase separation take place, respectively, and the formation of liquid crystalline phases or gels may prevail with respect to dispersions. We report on systems containing ss-DNA- and lysozyme-stabilized nanotubes, representative of different organization modes. In the former case, ss-DNA rolls around CNTs and ensures complete coverage. Conversely, proteins randomly and non-cooperatively adsorb onto nanotubes. The two functionalization mechanisms are significantly different. A fine-tuning of temperature, added polymer, pH, and/or ionic strength conditions induces the formation of a given supra-molecular organization mode. The biopolymer physico-chemical properties are relevant to induce the formation of different phases made of carbon nanotubes.

  1. Production and certain properties of biopolymers used in drilling

    Energy Technology Data Exchange (ETDEWEB)

    Dedusenko, G Y; Gvozdyak, R I; Kolodkova, N M; Matyshevskaya, M S; Mayko, I I

    1977-01-01

    Biopolymers, belonging to modified polysaccharides, obtained by the action of Xanthomonas campestris bacteria on glucose and containing its substances, are used as the main component in clayless polymer muds. As a result of research performed at the laboratory of phytopathogenic bacteria in the IMV AN USSR, the producent strain of polysaccharide has been revealed and the nutritive medium chosen. Results are given of an analysis of the best Soviet samples of biopolymers created in the IMV AN USSR, produced using various strains of Xanthomonas bacteria. Rheological properties of aqueous dispersions of the biopolymer Keltsan are studied. The flow curves are recorded on the Fann rotation viscosimeter. The research performed enables determination that for fermentation can be used the bacteria Xanthomonas campestris, X. begonia, and X. molvacearum; and bacteria belonging to X. Campestris used to produce a sample batch of biopolymer, yielding the greatest amount of polysaccharide. The work results in development of a nutritive medium based on available Soviet materials, promoting formation of polysaccharide.

  2. Biopolymer-based material used in optical image correlation

    Czech Academy of Sciences Publication Activity Database

    Mysliwiec, J.; Kochalska, Anna; Miniewicz, A.

    2008-01-01

    Roč. 47, č. 11 (2008), s. 1902-1906 ISSN 0003-6935 Institutional research plan: CEZ:AV0Z40500505 Keywords : biopolymer * DNA * optical correlation Subject RIV: CD - Macromolecular Chemistry Impact factor: 1.763, year: 2008

  3. Mechanics of biopolymer materials: Single chains to bulk properties

    NARCIS (Netherlands)

    Amuasi, H.E.; Storm, C.

    2010-01-01

    We outline the first stages in the multiscale modeling of biopolymer materials, starting with the statistical mechanics of single stiff chains. In the first coarse graining step, we demonstrate how to integrate out the single polymer degrees of freedom in supramolecular assemblies of such

  4. Segregative phase separation in aqueous mixtures of polydisperse biopolymers

    NARCIS (Netherlands)

    Edelman, M.W.

    2003-01-01

    Keywords: biopolymer, gelatine, dextran, PEO, phase separation, polydispersity, molar mass distribution, SEC-MALLS, CSLM The temperature-composition phase diagram of aqueous solutions of gelatine and dextran, which show liquid/liquid phase segregation, were explored at temperatures above the

  5. Thermal Degradation and Damping Characteristic of UV Irradiated Biopolymer

    Directory of Open Access Journals (Sweden)

    Anika Zafiah M. Rus

    2015-01-01

    Full Text Available Biopolymer made from renewable material is one of the most important groups of polymer because of its versatility in application. In this study, biopolymers based on waste vegetable oil were synthesized and cross-link with commercial polymethane polyphenyl isocyanate (known as BF. The BF was compressed by using hot compression moulding technique at 90°C based on the evaporation of volatile matter, known as compress biopolymer (CB. Treatment with titanium dioxide (TiO2 was found to affect the physical property of compressed biopolymer composite (CBC. The characterization of thermal degradation, activation energy, morphology structure, density, vibration, and damping of CB were determined after UV irradiation exposure. This is to evaluate the photo- and thermal stability of the treated CB or CBC. The vibration and damping characteristic of CBC samples is significantly increased with the increasing of UV irradiation time, lowest thickness, and percentages of TiO2 loading at the frequency range of 15–25 Hz due to the potential of the sample to dissipate energy during the oscillation harmonic system. The damping property of CBC was improved markedly upon prolonged exposure to UV irradiation.

  6. Film forming microbial biopolymers for commercial applications--a review.

    Science.gov (United States)

    Vijayendra, S V N; Shamala, T R

    2014-12-01

    Microorganisms synthesize intracellular, structural and extracellular polymers also referred to as biopolymers for their function and survival. These biopolymers play specific roles as energy reserve materials, protective agents, aid in cell functioning, the establishment of symbiosis, osmotic adaptation and support the microbial genera to function, adapt, multiply and survive efficiently under changing environmental conditions. Viscosifying, gelling and film forming properties of these have been exploited for specific significant applications in food and allied industries. Intensive research activities and recent achievements in relevant and important research fields of global interest regarding film forming microbial biopolymers is the subject of this review. Microbial polymers such as pullulan, kefiran, bacterial cellulose (BC), gellan and levan are placed under the category of exopolysaccharides (EPS) and have several other functional properties including film formation, which can be used for various applications in food and allied industries. In addition to EPS, innumerable bacterial genera are found to synthesis carbon energy reserves in their cells known as polyhydroxyalkanoates (PHAs), microbial polyesters, which can be extruded into films with excellent moisture and oxygen barrier properties. Blow moldable biopolymers like PHA along with polylactic acid (PLA) synthesized chemically in vitro using lactic acid (LA), which is produced by LA bacteria through fermentation, are projected as biodegradable polymers of the future for packaging applications. Designing and creating of new property based on requirements through controlled synthesis can lead to improvement in properties of existing polysaccharides and create novel biopolymers of great commercial interest and value for wider applications. Incorporation of antimicrobials such as bacteriocins or silver and copper nanoparticles can enhance the functionality of polymer films especially in food packaging

  7. Biopolymer chitin: extraction and characterization; Biopolimero quitina: extracao e caracterizacao

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2011-07-01

    The biopolymers are materials made from renewable sources such as soybean, corn, cane sugar, cellulose and chitin. Chitin is the most abundant biopolymer found in nature, after cellulose. The chemical structure of chitin is distinguished by the hydroxyl group, of structure from cellulose, located at position C-2, which in the chitin is replaced by acetamine group. The objective of this study was to develop the chitin from exoskeletons of Litopenaeus vannamei shrimp, which are discarded as waste, causing pollutions, environmental problems and thus obtain better utilization of these raw materials. It also, show the extraction process and deacetylation of chitosan. The extraction of chitin followed steps of demineralization, desproteinization and deodorization. Chitin and chitosan were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) and the thermals properties were analyzed by thermogravimetry (TG/DTG). (author)

  8. Corrosion Inhibition of High Speed Steel by Biopolymer HPMC Derivatives

    Directory of Open Access Journals (Sweden)

    Shih-Chen Shi

    2016-07-01

    Full Text Available The corrosion inhibition characteristics of the derivatives of biopolymer hydroxypropyl methylcellulose (HPMC, hydroxypropyl methylcellulose phthalate (HPMCP, and hydroxypropyl methylcellulose acetate succinate (HPMCAS film are investigated. Based on electrochemical impedance spectroscopic measurements and potentiodynamic polarization, the corrosion inhibition performance of high speed steel coated with HPMC derivatives is evaluated. The Nyquist plot and Tafel polarization demonstrate promising anti-corrosion performance of HPMC and HPMCP. With increasing film thickness, both materials reveal improvement in corrosion inhibition. Moreover, because of a hydrophobic surface and lower moisture content, HPMCP shows better anti-corrosion performance than HPMCAS. The study is of certain importance for designing green corrosion inhibitors of high speed steel surfaces by the use of biopolymer derivatives.

  9. Applications of Biopolymers Modified by Radiation Processing. Chapter 12

    Energy Technology Data Exchange (ETDEWEB)

    Tamada, M. [Takasaki Advanced Radiation Research Institute, Japan Atomic Energy Agency, Takasaki (Japan)

    2014-07-15

    Radiation processing using quantum beam such as electron beam and gamma rays is a clean process. Using this process, biopolymers with low environmental burden were modified for agricultural and environmental applications. High performance materials such as soil conditioner for arid area, spray coating Washi (Japanese paper), biodegradable dummy lens, chemically-induced biodegradable plastic, biodiesel catalyst, and plant growth promoter were developed by radiationinduced crosslinking, graft polymerization, and degradation. (author)

  10. PROPERTIES OF PREPARATIONS FUNCTIONAL BIOPOLYMERS OF A FISH ORIGIN

    Directory of Open Access Journals (Sweden)

    L. V. Antipova

    2014-01-01

    Full Text Available Development of theoretical and practical bases of technology of biocompatible materials of a domestic production on the basis of the natural polymeric systems allocated from raw materials of an animal, fish and a phytogenesis is actual in interests of development of science, health care, ecology. Now practically there are no domestic materials on the basis of products of modification of biopolymers for production of biocompatible materials with adjustable physical and chemical and biological properties. In this regard the special importance is gained by works on studying of functional properties of natural biopolymers, in particular collagen, elastin, hyaluronic acid. Interest of researchers to biopolymers of the proteinaceous nature is quite reasonable as they possess sufficient permeability, a big specific surface and sorption capacity, possibility of receiving convenient in technological forms, a low immunogenicity, possibility of regulation лизиса. Data on possible ways of use are presented in article secondary the collagenic wastes - skins of fishes of internal reservoirs of Russia. Innovative processing methods of processing of secondary raw materials with receiving functional biopolymers of a wide range of application are developed. With application of modern methods of researches their characteristics and property are defined. On a complex of organoleptic, physical and chemical indicators, indexes of biological activity the received preparations hyaluronic acid and collagen can find broad application in medicine, cosmetology. The resource-saving technology of receiving tanning semi-finished products easily giving in to further processing for the purpose of receiving leather haberdashery and textile production is developed. Thus, scientific new approaches in processing of skins of pond fishes on the basis of their deep processing are proved.

  11. Characterization of functional biopolymers under various external stimuli

    Energy Technology Data Exchange (ETDEWEB)

    Maleki, Atoosa

    2008-07-01

    Polymers are large molecules composed of repeating structural units connected by covalent chemical bonds. Biopolymers are a class of polymers produced by living organisms, which exhibit both biocompatible and biodegradable properties. The behavior of a biopolymer in solution is strongly dependent on the chemical and physical structure of the polymer chain, as well as external environmental conditions. To improve biopolymers in the direction of higher performance and better functionality, understanding of their physicochemical behavior and their response to external stimuli are of great importance. Rheology, rheo-small angle light scattering, dynamic light scattering, small angle neutron scattering, and asymmetric flow field-flow fractionation were utilized in this thesis to investigate the properties of hydroxyethyl cellulose and its hydrophobically modified analogue, as well as dextran, hyaluronan, and mucin under different conditions such as temperature, solvent, mechanical stress and strain, and radiation. Different novel hydrogels were prepared by using various chemical cross-linking agents. Specific features of these macromolecules provide them to be used as 'functional' materials, e.g., sensors, actuators, personal care products, enhanced oil recovery, and controlled drug delivery systems (author)

  12. Biopolymers to improve physical properties and leaching characteristics of mortar and concrete: A review

    Science.gov (United States)

    Olivia, M.; Jingga, H.; Toni, N.; Wibisono, G.

    2018-04-01

    The invention of environmentally friendly, high performance, and green material such as biopolymers marked an emerging trend for sustainable construction over the past decades. Biopolymer comprises of natural monomers and synthesized by plants or other organisms. The sustainable, biodegradable, and renewable biopolymers were used in concrete mixes to improve their physical and mechanical properties and durability. The aim of this paper is to provide a brief an overview of the impact of biopolymer addition into concrete and mortar mixes. Many studies on the influence of biopolymer on the properties of concrete and mortar by adding biopolymers at a certain proportion (usually less than one wt.%) to the concrete or mortar mixes, and the heavy metal leaching, rheological, and mechanical properties of the mixes were conducted. Biopolymers included in this review are chitosan (CH), xanthan gum (XG), guar gum (GG), lignosulphonate (LS), and cellulose ethers (CE). Data from previous studies showed that the addition of certain types of biopolymer into concrete and mortar mixes improve workability, water retention, and compressive strength by up to 30 percent. Chitosan strengthens heavy metal encapsulation in the mortar and neutralizes the negative impact of heavy metal on the mortar properties and environment. To sum up, the use of biopolymers improve physical properties and leaching characteristics of mortar and concrete.

  13. Improvements in or relating to systems for measuring radioactivity of labelled biopolymers

    International Nuclear Information System (INIS)

    Gross, V.N.

    1980-01-01

    A system for measuring radioactivity of labelled biopolymers, comprises a set of containers for containing aqueous solutions of biological samples containing biopolymers; an electric drive for setting the set of containers in stepwise motion: means for acid precipitation of biopolymers arranged to provide feeding of preset volumes of a coprecipitator and a suspension of diatomite in an acid solution to the containers: means for removal of suspensions, filtering, suspending the precipitate, dissolving the biopolymers and consecutively feeding the mixture and a scintillator to a detection chamber, and a measuring cell arranged in the detection chamber. The sequence of operations is controlled automatically. (author)

  14. Introduction of soft X-ray spectromicroscopy as an advanced technique for plant biopolymers research.

    Directory of Open Access Journals (Sweden)

    Chithra Karunakaran

    Full Text Available Soft X-ray absorption spectroscopy coupled with nano-scale microscopy has been widely used in material science, environmental science, and physical sciences. In this work, the advantages of soft X-ray absorption spectromicroscopy for plant biopolymer research were demonstrated by determining the chemical sensitivity of the technique to identify common plant biopolymers and to map the distributions of biopolymers in plant samples. The chemical sensitivity of soft X-ray spectroscopy to study biopolymers was determined by recording the spectra of common plant biopolymers using soft X-ray and Fourier Transform mid Infrared (FT-IR spectroscopy techniques. The soft X-ray spectra of lignin, cellulose, and polygalacturonic acid have distinct spectral features. However, there were no distinct differences between cellulose and hemicellulose spectra. Mid infrared spectra of all biopolymers were unique and there were differences between the spectra of water soluble and insoluble xylans. The advantage of nano-scale spatial resolution exploited using soft X-ray spectromicroscopy for plant biopolymer research was demonstrated by mapping plant cell wall biopolymers in a lentil stem section and compared with the FT-IR spectromicroscopy data from the same sample. The soft X-ray spectromicroscopy enables mapping of biopolymers at the sub-cellular (~30 nm resolution whereas, the limited spatial resolution in the micron scale range in the FT-IR spectromicroscopy made it difficult to identify the localized distribution of biopolymers. The advantages and limitations of soft X-ray and FT-IR spectromicroscopy techniques for biopolymer research are also discussed.

  15. ENCAPSULATION OF ANTITUBERCULAR DRUGS BY BIOPOLYMERS AND POLYELECTROLYTE MULTILAYERS

    Directory of Open Access Journals (Sweden)

    B. H. Mussabayeva

    2017-01-01

    Full Text Available The problem of drug-resistant tuberculosis treatment is complex and urgent: the standardof treatment includes the oral administration of six names of antibiotics, i.e. up totwenty tablets a day by the patient. This causes severe side effects, including those appeareddue to the formation of toxic products of drug interactions in the body. Therefore, itis important that some drugs dissolve in a stomach, and others – in the intestine, which willlead to increased bioavailability, reduced dosage and toxicity. The development of targeteddelivery systems for drugs with controlled release, targeted delivery and minimization ofside effects are of interest. One of the promising methods is polyelectrolytic multilayersand the technology of creating such layers by a step-by-step adsorption of heterogeneouslycharged polyelectrolytes.The aim of this article is the microencapsulation of anti-tuberculousdrugs into biopolymers coated with polyelectrolytic multilayers, and the solubilitystudy of microcapsules at pH values simulating various parts of the gastrointestinal tract.Materials and methods. Drugs as isoniazide, pyrazinamide, moxifloxacin, and biopolymers:gellan, pectin and sodium alginate, chitosan and dextran sulfate, as well as EudragitS are used to prepare microcapsules. The obtained microcapsules are studied by a methodof scanning electron microscopy. Quantitative determination of the effectiveness of the inclusionof drugs in microcapsules was carried out using pharmacopoeial methods.Results and discussion. The inclusion efficiency rises with an increase of biopolymer concentration. The inclusion efficiency increases in the row isoniazide

  16. Flexible design of band gaps in the biopolymer photonic crystals

    International Nuclear Information System (INIS)

    Savić-Šević, S

    2012-01-01

    One-dimensional photonic crystals (PC) are fabricated in dichromate-sensitized biopolymer as volume holograms. The flexibility of the PC band gap (BG) parameters was investigated. The spectral position of a BG can be varied by changing the exposure for two concentrations of sensitizer during the fabrication process. The spectral measurements show that the BG centre shifts towards longer wavelengths with decreasing exposure and concentration of the sensitizer. A tuning of the position of the BG for about 120 nm was obtained.

  17. Biopolymer nanostructures induced by plasma irradiation and metal sputtering

    Czech Academy of Sciences Publication Activity Database

    Slepička, P.; Juřík, P.; Malinský, Petr; Macková, Anna; Kasálková-Slepičková, N.; Švorčík, V.

    2014-01-01

    Roč. 332, 7-10 (2014), s. 7-10 ISSN 0168-583X. [21st International Conference on Ion Beam Analysis (IBA). Seattle, 23.06.2013-28.06.2013] R&D Projects: GA ČR ga13-06609S; GA ČR(CZ) GAP108/10/1106 Institutional support: RVO:61389005 Keywords : Biopolymer * plasma * surface morphology * RBS * Ripple pattern Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 1.124, year: 2014

  18. Chemical modeling of acid-base properties of soluble biopolymers derived from municipal waste treatment materials.

    Science.gov (United States)

    Tabasso, Silvia; Berto, Silvia; Rosato, Roberta; Marinos, Janeth Alicia Tafur; Ginepro, Marco; Zelano, Vincenzo; Daniele, Pier Giuseppe; Montoneri, Enzo

    2015-02-04

    This work reports a study of the proton-binding capacity of biopolymers obtained from different materials supplied by a municipal biowaste treatment plant located in Northern Italy. One material was the anaerobic fermentation digestate of the urban wastes organic humid fraction. The others were the compost of home and public gardening residues and the compost of the mix of the above residues, digestate and sewage sludge. These materials were hydrolyzed under alkaline conditions to yield the biopolymers by saponification. The biopolymers were characterized by 13C NMR spectroscopy, elemental analysis and potentiometric titration. The titration data were elaborated to attain chemical models for interpretation of the proton-binding capacity of the biopolymers obtaining the acidic sites concentrations and their protonation constants. The results obtained with the models and by NMR spectroscopy were elaborated together in order to better characterize the nature of the macromolecules. The chemical nature of the biopolymers was found dependent upon the nature of the sourcing materials.

  19. Associative Interactions in Crowded Solutions of Biopolymers Counteract Depletion Effects.

    Science.gov (United States)

    Groen, Joost; Foschepoth, David; te Brinke, Esra; Boersma, Arnold J; Imamura, Hiromi; Rivas, Germán; Heus, Hans A; Huck, Wilhelm T S

    2015-10-14

    The cytosol of Escherichia coli is an extremely crowded environment, containing high concentrations of biopolymers which occupy 20-30% of the available volume. Such conditions are expected to yield depletion forces, which strongly promote macromolecular complexation. However, crowded macromolecule solutions, like the cytosol, are very prone to nonspecific associative interactions that can potentially counteract depletion. It remains unclear how the cytosol balances these opposing interactions. We used a FRET-based probe to systematically study depletion in vitro in different crowded environments, including a cytosolic mimic, E. coli lysate. We also studied bundle formation of FtsZ protofilaments under identical crowded conditions as a probe for depletion interactions at much larger overlap volumes of the probe molecule. The FRET probe showed a more compact conformation in synthetic crowding agents, suggesting strong depletion interactions. However, depletion was completely negated in cell lysate and other protein crowding agents, where the FRET probe even occupied slightly more volume. In contrast, bundle formation of FtsZ protofilaments proceeded as readily in E. coli lysate and other protein solutions as in synthetic crowding agents. Our experimental results and model suggest that, in crowded biopolymer solutions, associative interactions counterbalance depletion forces for small macromolecules. Furthermore, the net effects of macromolecular crowding will be dependent on both the size of the macromolecule and its associative interactions with the crowded background.

  20. Integrated bioconversion of syngas into bioethanol and biopolymers.

    Science.gov (United States)

    Lagoa-Costa, Borja; Abubackar, Haris Nalakath; Fernández-Romasanta, María; Kennes, Christian; Veiga, María C

    2017-09-01

    Syngas bioconversion is a promising method for bioethanol production, but some VFA remains at the end of fermentation. A two-stage process was set-up, including syngas fermentation as first stage under strict anaerobic conditions using C. autoethanogenum as inoculum, with syngas (CO/CO 2 /H 2 /N 2 , 30/10/20/40) as gaseous substrate. The second stage consisted in various fed-batch assays using a highly enriched PHA accumulating biomass as inoculum, where the potential for biopolymer production from the remaining acetic acid at the end of the syngas fermentation was evaluated. All of the acetic acid was consumed and accumulated as biopolymer, while ethanol and 2,3-butanediol remained basically unused. It can be concluded that a high C/N ratio in the effluent from the syngas fermentation stage was responsible for non-consumption of alcohols. A maximum PHA content of 24% was reached at the end of the assay. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. Fabrication of Porous Materials from Natural/Synthetic Biopolymers and Their Composites

    Directory of Open Access Journals (Sweden)

    Udeni Gunathilake T.M. Sampath

    2016-12-01

    Full Text Available Biopolymers and their applications have been widely studied in recent years. Replacing the oil based polymer materials with biopolymers in a sustainable manner might give not only a competitive advantage but, in addition, they possess unique properties which cannot be emulated by conventional polymers. This review covers the fabrication of porous materials from natural biopolymers (cellulose, chitosan, collagen, synthetic biopolymers (poly(lactic acid, poly(lactic-co-glycolic acid and their composite materials. Properties of biopolymers strongly depend on the polymer structure and are of great importance when fabricating the polymer into intended applications. Biopolymers find a large spectrum of application in the medical field. Other fields such as packaging, technical, environmental, agricultural and food are also gaining importance. The introduction of porosity into a biomaterial broadens the scope of applications. There are many techniques used to fabricate porous polymers. Fabrication methods, including the basic and conventional techniques to the more recent ones, are reviewed. Advantages and limitations of each method are discussed in detail. Special emphasis is placed on the pore characteristics of biomaterials used for various applications. This review can aid in furthering our understanding of the fabrication methods and about controlling the porosity and microarchitecture of porous biopolymer materials.

  2. Fabrication of Porous Materials from Natural/Synthetic Biopolymers and Their Composites.

    Science.gov (United States)

    Sampath, Udeni Gunathilake T M; Ching, Yern Chee; Chuah, Cheng Hock; Sabariah, Johari J; Lin, Pai-Chen

    2016-12-07

    Biopolymers and their applications have been widely studied in recent years. Replacing the oil based polymer materials with biopolymers in a sustainable manner might give not only a competitive advantage but, in addition, they possess unique properties which cannot be emulated by conventional polymers. This review covers the fabrication of porous materials from natural biopolymers (cellulose, chitosan, collagen), synthetic biopolymers (poly(lactic acid), poly(lactic- co -glycolic acid)) and their composite materials. Properties of biopolymers strongly depend on the polymer structure and are of great importance when fabricating the polymer into intended applications. Biopolymers find a large spectrum of application in the medical field. Other fields such as packaging, technical, environmental, agricultural and food are also gaining importance. The introduction of porosity into a biomaterial broadens the scope of applications. There are many techniques used to fabricate porous polymers. Fabrication methods, including the basic and conventional techniques to the more recent ones, are reviewed. Advantages and limitations of each method are discussed in detail. Special emphasis is placed on the pore characteristics of biomaterials used for various applications. This review can aid in furthering our understanding of the fabrication methods and about controlling the porosity and microarchitecture of porous biopolymer materials.

  3. Introduction of Microbial Biopolymers in Soil Treatment for Future Environmentally-Friendly and Sustainable Geotechnical Engineering

    Directory of Open Access Journals (Sweden)

    Ilhan Chang

    2016-03-01

    Full Text Available Soil treatment and improvement is commonly performed in the field of geotechnical engineering. Methods and materials to achieve this such as soil stabilization and mixing with cementitious binders have been utilized in engineered soil applications since the beginning of human civilization. Demand for environment-friendly and sustainable alternatives is currently rising. Since cement, the most commonly applied and effective soil treatment material, is responsible for heavy greenhouse gas emissions, alternatives such as geosynthetics, chemical polymers, geopolymers, microbial induction, and biopolymers are being actively studied. This study provides an overall review of the recent applications of biopolymers in geotechnical engineering. Biopolymers are microbially induced polymers that are high-tensile, innocuous, and eco-friendly. Soil–biopolymer interactions and related soil strengthening mechanisms are discussed in the context of recent experimental and microscopic studies. In addition, the economic feasibility of biopolymer implementation in the field is analyzed in comparison to ordinary cement, from environmental perspectives. Findings from this study demonstrate that biopolymers have strong potential to replace cement as a soil treatment material within the context of environment-friendly construction and development. Moreover, continuing research is suggested to ensure performance in terms of practical implementation, reliability, and durability of in situ biopolymer applications for geotechnical engineering purposes.

  4. Rapid nano impact printing of silk biopolymer thin films

    Science.gov (United States)

    White, Robert D.; Gray, Caprice; Mandelup, Ethan; Amsden, Jason J.; Kaplan, David L.; Omenetto, Fiorenzo G.

    2011-11-01

    In this paper, nano impact printing of silk biopolymer films is described. An indenter is rapidly accelerated and transfers the nanopattern from a silicon master into the silk film during an impact event that occurs in less than 1 ms. Contact stresses of greater than 100 MPa can be achieved during the short impact period with low power and inexpensive hardware. Ring shaped features with a diameter of 2 µm and a ring width of 100-200 nm were successfully transferred into untreated silk films using this method at room temperature. Mechanical modeling was carried out to determine the contact stress distribution, and demonstrates that imprinting can occur for contact stresses of less than 2 MPa. Thermal characterization at the impact location shows that raising the temperature to 70 °C has only a limited effect on pattern transfer. Contact stresses of greater than approximately 100 MPa result in excessive deformation of the film and poor pattern transfer.

  5. Rapid nano impact printing of silk biopolymer thin films

    International Nuclear Information System (INIS)

    White, Robert D; Gray, Caprice; Mandelup, Ethan; Amsden, Jason J; Kaplan, David L; Omenetto, Fiorenzo G

    2011-01-01

    In this paper, nano impact printing of silk biopolymer films is described. An indenter is rapidly accelerated and transfers the nanopattern from a silicon master into the silk film during an impact event that occurs in less than 1 ms. Contact stresses of greater than 100 MPa can be achieved during the short impact period with low power and inexpensive hardware. Ring shaped features with a diameter of 2 µm and a ring width of 100–200 nm were successfully transferred into untreated silk films using this method at room temperature. Mechanical modeling was carried out to determine the contact stress distribution, and demonstrates that imprinting can occur for contact stresses of less than 2 MPa. Thermal characterization at the impact location shows that raising the temperature to 70 °C has only a limited effect on pattern transfer. Contact stresses of greater than approximately 100 MPa result in excessive deformation of the film and poor pattern transfer.

  6. 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.

  7. Conjugates of a Photoactivated Rhodamine with Biopolymers for Cell Staining

    Science.gov (United States)

    Zaitsev, Sergei Yu.; Shaposhnikov, Mikhail N.; Solovyeva, Daria O.; Solovyeva, Valeria V.; Rizvanov, Albert A.

    2014-01-01

    Conjugates of the photoactivated rhodamine dyes with biopolymers (proteins, polysaccharides, and nucleic acids) are important tools for microscopic investigation of biological tissue. In this study, a precursor of the photoactivated fluorescent dye (PFD) has been successfully used for staining of numerous mammalian cells lines and for conjugate formation with chitosan (“Chitosan-PFD”) and histone H1 (“Histone H1.3-PFD”). The intensive fluorescence has been observed after photoactivation of these conjugates inside cells (A431, HaCaT, HEK239, HBL-100, and MDCK). Developed procedures and obtained data are important for further application of novel precursors of fluorescent dyes (“caged” dyes) for microscopic probing of biological objects. Thus, the synthesized “Chitosan-PFD” and “Histone H1-PFD” have been successfully applied in this study for intracellular transport visualization by fluorescent microscopy. PMID:25383365

  8. Biopolymer nanostructures induced by plasma irradiation and metal sputtering

    Energy Technology Data Exchange (ETDEWEB)

    Slepička, P., E-mail: petr.slepicka@vscht.cz [Department of Solid State Engineering, Institute of Chemical Technology, 166 28 Prague (Czech Republic); Juřík, P. [Department of Solid State Engineering, Institute of Chemical Technology, 166 28 Prague (Czech Republic); Malinský, P.; Macková, A. [Nuclear Physics Institute, Academy of Sciences of the Czech Republic, Rez, Prague 25068 (Czech Republic); Faculty of Science, J.E. Purkyně University, Ústí nad Labem (Czech Republic); Kasálková, N. Slepičková; Švorčík, V. [Department of Solid State Engineering, Institute of Chemical Technology, 166 28 Prague (Czech Republic)

    2014-08-01

    Modification based on polymer surface exposure to plasma treatment exhibits an easy and cheap technique for polymer surface nanostructuring. The influence of argon plasma treatment on biopolymer poly(L-lactide acid (PLLA) will be presented in this paper. The combination of Ar{sup +} ion irradiation, consequent sputter metallization (platinum) and thermal annealing of polymer surface will be summarized. The surface morphology was studied using atomic force microscopy. The Rutherford Backscattering Spectroscopy and X-ray Photoelectron Spectroscopy were used as analytical methods. The combination of plasma treatment with consequent thermal annealing and/or metal sputtering led to the change of surface morphology and its elemental ratio. The surface roughness and composition has been strongly influenced by the modification parameters and metal layer thickness. By plasma treatment of polymer surface combined with consequent annealing or metal deposition can be prepared materials applicable both in tissue engineering as cell carriers, but also in integrated circuit manufacturing.

  9. 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.

  10. 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

  11. Time domain NMR and conductivity study of apple pectin biopolymers

    International Nuclear Information System (INIS)

    Mattos, Ritamara I.; Souto, Sergio; Tambelli, Caio E.

    2015-01-01

    This communication presents results of "1H nuclear magnetic resonance of continuous distributions of spin-spin relaxation time (T_2) and A.C. conductivity of apple pectin biopolymers plasticized with glycerol and containing acetic acid. The continuous distributions reveals up to three components of spin-spin relaxation times (T_2). The two short T_2 components were associated with protons of pectin polymer chain and the longer T_2 can be attributed with the protons of the glycerol. The conductivity values increase with glycerol concentration with maximum at 7.9 x 10"-"4 S cm"-"1 for sample with 3.0 g of glycerol at 83 deg C. The behavior of activation energy and T_2 continuous distribution indicate an increase of proton mobility due the structural changes caused by glycerol addition. (author)

  12. Is there a field-theoretic explanation for precursor biopolymers?

    Science.gov (United States)

    Rosen, Gerald

    2002-08-01

    A Hu-Barkana-Gruzinov cold dark matter scalar field phi may enter a weak isospin invariant derivative interaction that causes the flow of right-handed electrons to align parallel to (inverted delta phi). Hence, in the outer regions of galaxies where (inverted delta phi) is large, as in galactic halos, the derivative interaction may induce a chirality-imbued quantum chemistry. Such a chirality-imbued chemistry would in turn be conducive to the formation of abundant precursor biopolymers on interstellar dust grains, comets and meteors in galactic halo regions, with subsequent delivery to planets in the inner galactic regions where phi and (inverted delta phi) are concomitantly near zero and left-right symmetric terrestrial quantum chemistry prevails.

  13. Extraction of cellulose microcrystalline from galam wood for biopolymer

    Science.gov (United States)

    Ismail, Ika; Sa'adiyah, Devy; Rahajeng, Putri; Suprayitno, Abdi; Andiana, Rocky

    2018-04-01

    Consumption of plastic raw materials tends to increase, but until now the meet of the consumption of plastic raw are still low, even some are still imported. Nowadays, Indonesia's plastic needs are supported by petrochemicals where raw materials are still dependent abroad and petropolymer raw materials are derived from petroleum which will soon be depleted due to rising petroleum needs. Therefore, various studies have been conducted to develop natural fiber-based polymers that are biodegradable and abundant in nature. It is because the natural polymer production process is very efficient and very environmentally friendly. There have been many studies of biopolymers especially natural fiber-based polymers from plants, due to plants containing cellulose, hemicellulose and lignin. However, cellulose is the only one who has crystalline structures. Cellulose has a high crystality compared to amorphous lignin and hemicellulose. In this study, extracted cellulose as biopolymer and amplifier on composite. The cellulose is extracted from galam wood from East Kalimantan. Cellulose extraction will be obtained in nano / micro form through chemical and mechanical treatment processes. The chemical treatment of cellulose extraction is alkalinization process using NaOH solution, bleaching using NaClO2 and acid hydrolysis using sulfuric acid. After chemical treatment, ultrasonic mechanical treatment is made to make cellulose fibers into micro or nano size. Besides, cellulose results will be characterized. Characterization was performed to analyze molecules of cellulose compounds extracted from plants using Fourier Transformation Infra Red (FTIR) testing. XRD testing to analyze cellulose crystallinity. Scanning Electron Microscope (SEM) test to analyze morphology and fiber size.

  14. Load sharing in the growth of bundled biopolymers.

    Science.gov (United States)

    Wang, Ruizhe; Carlsson, A E

    2014-11-01

    To elucidate the nature of load sharing in the growth of multiple biopolymers, we perform stochastic simulations of the growth of biopolymer bundles against obstacles under a broad range of conditions and varying assumptions. The obstacle motion due to thermal fluctuations is treated explicitly. We assume the "Perfect Brownian Ratchet" (PBR) model, in which the polymerization rate equals the free-filament rate as soon as the filament-obstacle distance exceeds the monomer size. Accurate closed-form formulas are obtained for the case of a rapidly moving obstacle. We find the following: (1) load sharing is usually sub-perfect in the sense that polymerization is slower than for a single filament carrying the same average force; (2) the sub-perfect behavior becomes significant at a total force proportional to the logarithm or the square root of the number of filaments, depending on the alignment of the filaments; (3) for the special case of slow barrier diffusion and low opposing force, an enhanced obstacle velocity for an increasing number of filaments is possible; (4) the obstacle velocity is very sensitive to the alignment of the filaments in the bundle, with a staggered alignment being an order of magnitude faster than an unstaggered one at forces of only 0.5 pN per filament for 20 filaments; (5) for large numbers of filaments, the power is maximized at a force well below 1 pN per filament; (6) for intermediate values of the obstacle diffusion coefficient, the shape of the force velocity relation is very similar to that for rapid obstacle diffusion.

  15. Lithium ion conducting biopolymer electrolyte based on pectin doped with Lithium nitrate

    Science.gov (United States)

    Manjuladevi, R.; Selvin, P. Christopher; Selvasekarapandian, S.; Shilpa, R.; Moniha, V.

    2018-04-01

    The Biopolymer electrolyte based on pectin doped with lithium nitrate of different concentrations have been prepared by solution casting technique. The decrease in crystalline nature of the biopolymer has been identified by XRD analyses. The complex formation between the polymer and the salt has been revealed using FTIR analysis. The ionic conductivity has been explored using A.C. impedance spectroscopy which reveals that the biopolymer containing 30 wt% Pectin: 70wt%LiNO3 has highest ionic conductivity of 3.97 × 10-3 Scm-1.

  16. Genotoxicity of clays with potential use in biopolymers for food packaging

    DEFF Research Database (Denmark)

    Sharma, Anoop Kumar; Mortensen, Alicja; Hadrup, Niels

    Genotoxicity of clays with potential use in biopolymers for food packaging Plastics produced from biopolymers are of commercial interest as they are manufactured from renewable resources such as agricultural crop wastes and have the potential to meet environmental and health requirements. Biopoly......Genotoxicity of clays with potential use in biopolymers for food packaging Plastics produced from biopolymers are of commercial interest as they are manufactured from renewable resources such as agricultural crop wastes and have the potential to meet environmental and health requirements...... in crude suspensions (suspended in cell culture medium) and crude suspensions filtrated through a 0.2 µm pore size filter in order to investigate the potential effect of “nanoparticles” only. The two clays showed noticeable differences in genotoxicity; both crude and filtered suspensions of Cloisite...

  17. Single walled carbon nanotubes functionally adsorbed to biopolymers for use as chemical sensors

    Science.gov (United States)

    Johnson, Jr., Alan T.; Gelperin, Alan [Princeton, NJ; Staii, Cristian [Madison, WI

    2011-07-12

    Chemical field effect sensors comprising nanotube field effect devices having biopolymers such as single stranded DNA functionally adsorbed to the nanotubes are provided. Also included are arrays comprising the sensors and methods of using the devices to detect volatile compounds.

  18. Spatially resolved microrheology of heterogeneous biopolymer hydrogels using covalently bound microspheres

    NARCIS (Netherlands)

    Wong, L.H.; Kurniawan, Nicholas A.; Too, H.-P.; Rajagopalan, R.

    2014-01-01

    Characterization of the rheological properties of heterogeneous biopolymers is important not only to understand the effect of substrate elasticity on cell behaviors, but also to provide insights into mechanical changes during cellular remodeling of the environment. Conventional particle-tracking

  19. Hydrogels from Biopolymer Hybrid for Biomedical, Food, and Functional Food Applications

    Directory of Open Access Journals (Sweden)

    Robert C. Spiro

    2012-04-01

    Full Text Available Hybrid hydrogels from biopolymers have been applied for various indications across a wide range of biomedical, pharmaceutical, and functional food industries. In particular, hybrid hydrogels synthesized from two biopolymers have attracted increasing attention. The inclusion of a second biopolymer strengthens the stability of resultant hydrogels and enriches its functionalities by bringing in new functional groups or optimizing the micro-environmental conditions for certain biological and biochemical processes. This article presents approaches that have been used by our groups to synthesize biopolymer hybrid hydrogels for effective uses for immunotherapy, tissue regeneration, food and functional food applications. The research has achieved some challenging results, such as stabilizing physical structure, increasing mucoadhesiveness, and the creation of an artificial extracellular matrix to aid in guiding tissue differentiation.

  20. About possible mechanisms of current transfer in the bio-polymer - semiconductor heterostructure

    International Nuclear Information System (INIS)

    Pavlov, A.A.; Dosmailov, M.A.; Karibaeva, M.K.; Kenshinbaev, N.K.; Kokanbaev, M.; Uristembekov, B.B.; Tynyshtykbaev, K.B.

    2003-01-01

    Earlier by the bio-polymer films deposition on silicon the bio-polymer - semiconductor heterostructures were created. The influence of silicon surface atoms on self-organization processes in these bio-molecules were studied. Particularly the silicon - bio-cholesterol aqueous solution and the silicon - bio-chlorophyll aqueous solution spectral photo-sensitivity were considered. In this case the of photo-response broadening in the spectral photo-sensitivity short-wave part of these systems have been observed. The similar broadening is explained by both the passivation of surface recombination centers by OH-groups and the anti-reflecting properties of aqueous solutions. Besides it is possible the additional charge carriers generation caused by quasi-inter-zone transfers in the bio-polymers depending on electron-conformation properties of macromolecules. In the paper the possible mechanisms of current transfer in the bio-polymer - semiconductor heterostructure are discussed

  1. Biopolymer Electrolyte Based on Derivatives of Cellulose from Kenaf Bast Fiber

    Directory of Open Access Journals (Sweden)

    Mohd Saiful Asmal Rani

    2014-09-01

    Full Text Available A cellulose derivative, carboxymethyl cellulose (CMC, was synthesized by the reaction of cellulose from kenaf bast fiber with monochloroacetic acid. A series of biopolymer electrolytes comprised of the synthesized CMC and ammonium acetate (CH3COONH4 were prepared by the solution-casting technique. The biopolymer-based electrolyte films were characterized by Fourier Transform Infrared spectroscopy to investigate the formation of the CMC–CH3COONH4 complexes. Electrochemical impedance spectroscopy was conducted to obtain their ionic conductivities. The highest conductivity at ambient temperature of 5.77 × 10−4 S cm−1 was obtained for the electrolyte film containing 20 wt% of CH3COONH4. The biopolymer electrolyte film also exhibited electrochemical stability up to 2.5 V. These results indicated that the biopolymer electrolyte has great potential for applications to electrochemical devices, such as proton batteries and solar cells.

  2. The estimation of harmfulness for environment of moulding sand with biopolymer binder based on polylactide

    Directory of Open Access Journals (Sweden)

    K. Major-Gabryś

    2011-01-01

    Full Text Available The article takes into consideration technological and ecological aspects of IV generation moulding sands. Investigations concerning anapplication of biopolymer materials as binders for moulding sands are presented in the paper. These investigations are the continuation ofexaminations related to applications of various biopolymers as binding agents and to the properties of the moulding sands with biopolymerbinders. In the paper there are the researches concerning analyzing gases emitted from moulding sands during heating.

  3. Massive calculations of electrostatic potentials and structure maps of biopolymers in a distributed computing environment

    International Nuclear Information System (INIS)

    Akishina, T.P.; Ivanov, V.V.; Stepanenko, V.A.

    2013-01-01

    Among the key factors determining the processes of transcription and translation are the distributions of the electrostatic potentials of DNA, RNA and proteins. Calculations of electrostatic distributions and structure maps of biopolymers on computers are time consuming and require large computational resources. We developed the procedures for organization of massive calculations of electrostatic potentials and structure maps for biopolymers in a distributed computing environment (several thousands of cores).

  4. The Influence of Biopolym FTZ on the Content of Nitrogen Compounds in Rumen

    OpenAIRE

    Eva Petrášková; Jana Hnisová; Bohuslav Čermák; Šoch Miloslav; Bohuslav Vostoupal

    2010-01-01

    The aim of this study was to verify the effect of Biopolym FZT on the crude protein in the ruminal content. The experiment was conducted in laboratory conditions. Rumen content was removed from the Holstein breed cow fitted with ruminal fistula. The hydrolyzed brown seaweed was added to the samples of the ruminal content. After incubation of the samples the crude protein content was determined. In experiments with solid ruminal contents positive effects of Biopolym on the crude protein conten...

  5. Do single-use medical devices containing biopolymers reduce the environmental impacts of surgical procedures compared with their plastic equivalents?

    Science.gov (United States)

    Unger, Scott R; Hottle, Troy A; Hobbs, Shakira R; Thiel, Cassandra L; Campion, Nicole; Bilec, Melissa M; Landis, Amy E

    2017-01-01

    Background While petroleum-based plastics are extensively used in health care, recent developments in biopolymer manufacturing have created new opportunities for increased integration of biopolymers into medical products, devices and services. This study compared the environmental impacts of single-use disposable devices with increased biopolymer content versus typically manufactured devices in hysterectomy. Methods A comparative life cycle assessment of single-use disposable medical products containing plastic(s) versus the same single-use medical devices with biopolymers substituted for plastic(s) at Magee-Women's Hospital (Magee) in Pittsburgh, PA and the products used in four types of hysterectomies that contained plastics potentially suitable for biopolymer substitution. Magee is a 360-bed teaching hospital, which performs approximately 1400 hysterectomies annually. Results There are life cycle environmental impact tradeoffs when substituting biopolymers for petroplastics in procedures such as hysterectomies. The substitution of biopolymers for petroleum-based plastics increased smog-related impacts by approximately 900% for laparoscopic and robotic hysterectomies, and increased ozone depletion-related impacts by approximately 125% for laparoscopic and robotic hysterectomies. Conversely, biopolymers reduced life cycle human health impacts, acidification and cumulative energy demand for the four hysterectomy procedures. The integration of biopolymers into medical products is correlated with reductions in carcinogenic impacts, non-carcinogenic impacts and respiratory effects. However, the significant agricultural inputs associated with manufacturing biopolymers exacerbate environmental impacts of products and devices made using biopolymers. Conclusions The integration of biopolymers into medical products is correlated with reductions in carcinogenic impacts, non-carcinogenic impacts and respiratory effects; however, the significant agricultural inputs associated

  6. In planta production of ELPylated spidroin-based proteins results in non-cytotoxic biopolymers.

    Science.gov (United States)

    Hauptmann, Valeska; Menzel, Matthias; Weichert, Nicola; Reimers, Kerstin; Spohn, Uwe; Conrad, Udo

    2015-02-19

    Spider silk is a tear-resistant and elastic biopolymer that has outstanding mechanical properties. Additionally, exiguous immunogenicity is anticipated for spider silks. Therefore, spider silk represents a potential ideal biomaterial for medical applications. All known spider silk proteins, so-called spidroins, reveal a composite nature of silk-specific units, allowing the recombinant production of individual and combined segments. In this report, a miniaturized spidroin gene, named VSO1 that contains repetitive motifs of MaSp1 has been synthesized and combined to form multimers of distinct lengths, which were heterologously expressed as elastin-like peptide (ELP) fusion proteins in tobacco. The elastic penetration moduli of layered proteins were analyzed for different spidroin-based biopolymers. Moreover, we present the first immunological analysis of synthetic spidroin-based biopolymers. Characterization of the binding behavior of the sera after immunization by competitive ELISA suggested that the humoral immune response is mainly directed against the fusion partner ELP. In addition, cytocompatibility studies with murine embryonic fibroblasts indicated that recombinant spidroin-based biopolymers, in solution or as coated proteins, are well tolerated. The results show that spidroin-based biopolymers can induce humoral immune responses that are dependent on the fusion partner and the overall protein structure. Furthermore, cytocompatibility assays gave no indication of spidroin-derived cytotoxicity, suggesting that recombinant produced biopolymers composed of spider silk-like repetitive elements are suitable for biomedical applications.

  7. A Biogeotechnical approach to Stabilize Soft Marine Soil with a Microbial Organic Material called Biopolymer

    Science.gov (United States)

    Chang, I.; Cho, G. C.; Kwon, Y. M.; Im, J.

    2017-12-01

    The importance and demands of offshore and coastal area development are increasing due to shortage of usable land and to have access to valuable marine resources. However, most coastal soils are soft sediments, mainly composed with fines (silt and clay) and having high water and organic contents, which induce complicated mechanical- and geochemical- behaviors and even be insufficient in Geotechnical engineering aspects. At least, soil stabilization procedures are required for those soft sediments, regardless of the purpose of usage on the site. One of the most common soft soil stabilization method is using ordinary cement as a soil strengthening binder. However, the use of cement in marine environments is reported to occur environmental concerns such as pH increase and accompanying marine ecosystem disturbance. Therefore, a new environmentally-friendly treatment material for coastal and offshore soils. In this study, a biopolymer material produced by microbes is introduced to enhance the physical behavior of a soft tidal flat sediment by considering the biopolymer rheology, soil mineralogy, and chemical properties of marine water. Biopolymer material used in this study forms inter-particle bonds between particles which is promoted through cation-bridges where the cations are provided from marine water. Moreover, biopolymer treatment renders unique stress-strain relationship of soft soils. The mechanical stiffness (M) instantly increase with the presence of biopolymer, while time-dependent settlement behavior (consolidation) shows a big delay due to the viscous biopolymer hydrogels in pore spaces.

  8. Designing biopolymer microgels to encapsulate, protect and deliver bioactive components: Physicochemical aspects.

    Science.gov (United States)

    McClements, David Julian

    2017-02-01

    Biopolymer microgels have considerable potential for their ability to encapsulate, protect, and release bioactive components. Biopolymer microgels are small particles (typically 100nm to 1000μm) whose interior consists of a three-dimensional network of cross-linked biopolymer molecules that traps a considerable amount of solvent. This type of particle is also sometimes referred to as a nanogel, hydrogel bead, biopolymer particles, or microsphere. Biopolymer microgels are typically prepared using a two-step process involving particle formation and particle gelation. This article reviews the major constituents and fabrication methods that can be used to prepare microgels, highlighting their advantages and disadvantages. It then provides an overview of the most important characteristics of microgel particles (such as size, shape, structure, composition, and electrical properties), and describes how these parameters can be manipulated to control the physicochemical properties and functional attributes of microgel suspensions (such as appearance, stability, rheology, and release profiles). Finally, recent examples of the utilization of biopolymer microgels to encapsulate, protect, or release bioactive agents, such as pharmaceuticals, nutraceuticals, enzymes, flavors, and probiotics is given. Copyright © 2016 Elsevier B.V. All rights reserved.

  9. Packaging related properties of commercially available biopolymers – An overview of the status quo

    Directory of Open Access Journals (Sweden)

    V. Jost

    2018-05-01

    Full Text Available Several commercially available thermoplastic biopolymers were processed in a continuous extrusion line. The molecular weight, crystallinity, and mechanical and permeation properties of the cast films were determined in order to evaluate the status quo of biopolymers currently commercially available. The biopolymers that were evaluated were polylactic acid (PLA, several polyhydroxyalkanoates (PHAs (Poly(3-hydroxybutyrate (PHB, poly(3-hydroxybutyrate-co-4-hydroxybutyrate (PHBHB, poly(3-hydroxybutyrate-co-3-hydroxyvalerate (PHBV, thermoplastic starch (TPS, polybutylene adipate terephthalate (PBAT, polybutylene succinate (PBS, polycaprolactone (PCL and biobased polyethylene (BioPE. Due to its potential for biobased production, thermoplastic polyurethane elastomer (TPU was also analysed. Mechanical analysis showed the PLA and PHA films had high strength and extremely low elongation at break. These were also the materials with the highest molecular weights. Films made of TPU, PCL, TPS, PBAT and BioPE had a significantly lower Young’s modulus and significantly higher elongation at break; these films had comparatively low molecular weights. Permeation measurements showed that PHA films, and particularly PHBV, had the lowest oxygen and water vapour permeability of the biopolymers that were analysed. The biopolymers BioPE, TPS, PCL, TPU and PBAT were highly permeable to oxygen, and had comparatively low molecular weight. The biopolymers TPU, PBS, PBAT, PCL and TPS were highly permeable to water vapour.

  10. Fabrication, functionalization, and application of electrospun biopolymer nanofibers.

    Science.gov (United States)

    Kriegel, Christina; Arecchi, Alessandra; Arrechi, Alessandra; Kit, Kevin; McClements, D J; Weiss, Jochen

    2008-09-01

    -fiber manufacturing with a particular emphasis on the use of biopolymers. We will review typical fabrication set-ups, discuss the influence of process conditions on nanofiber properties, and then review previous studies that describe the production of biopolymer-based nanofibers. Finally we briefly discuss emerging methods to further functionalize fibers and discuss potential applications in the area of food science and technology.

  11. New Guar Biopolymer Silver Nanocomposites for Wound Healing Applications

    Directory of Open Access Journals (Sweden)

    Runa Ghosh Auddy

    2013-01-01

    Full Text Available Wound healing is an innate physiological response that helps restore cellular and anatomic continuity of a tissue. Selective biodegradable and biocompatible polymer materials have provided useful scaffolds for wound healing and assisted cellular messaging. In the present study, guar gum, a polymeric galactomannan, was intrinsically modified to a new cationic biopolymer guar gum alkylamine (GGAA for wound healing applications. Biologically synthesized silver nanoparticles (Agnp were further impregnated in GGAA for extended evaluations in punch wound models in rodents. SEM studies showed silver nanoparticles well dispersed in the new guar matrix with a particle size of ~18 nm. In wound healing experiments, faster healing and improved cosmetic appearance were observed in the new nanobiomaterial treated group compared to commercially available silver alginate cream. The total protein, DNA, and hydroxyproline contents of the wound tissues were also significantly higher in the treated group as compared with the silver alginate cream (P<0.05. Silver nanoparticles exerted positive effects because of their antimicrobial properties. The nanobiomaterial was observed to promote wound closure by inducing proliferation and migration of the keratinocytes at the wound site. The derivatized guar gum matrix additionally provided a hydrated surface necessary for cell proliferation.

  12. Thermal Behavior of Tacca leontopetaloides Starch-Based Biopolymer

    Directory of Open Access Journals (Sweden)

    Nurul Shuhada Mohd Makhtar

    2013-01-01

    Full Text Available Starch is used whenever there is a need for natural elastic properties combined with low cost of production. However, the hydrophilic properties in structural starch will decrease the thermal performance of formulated starch polymer. Therefore, the effect of glycerol, palm olein, and crude palm oil (CPO, as plasticizers, on the thermal behavior of Tacca leontopetaloides starch incorporated with natural rubber in biopolymer production was investigated in this paper. Four different formulations were performed and represented by TPE1, TPE2, TPE3, and TPE4. The compositions were produced by using two-roll mill compounding. The sheets obtained were cut into small sizes prior to thermal testing. The addition of glycerol shows higher enthalpy of diffusion in which made the material easily can be degraded, leaving to an amount of 6.6% of residue. Blending of CPO with starch (TPE3 had a higher thermal resistance towards high temperature up to 310°C and the thermal behavior of TPE2 only gave a moderate performance compared with other TPEs.

  13. Ranitidine Loaded Biopolymer Floats: Designing, Characterization, and Evaluation

    Directory of Open Access Journals (Sweden)

    Abdul Karim

    2017-01-01

    Full Text Available The float formulation is a strategy to improve the bioavailability of drugs by gastroretentive drug delivery system (GRDDS. A drug delivery model based on swellable and reswellable low density biopolymers has been designed to evaluate its drug release profile using ranitidine (RNT as a model drug and formulations have been prepared utilizing 32 factorial designs. The drug release (DR data has been subjected to various kinetic models to investigate the DR mechanism. A reduction in rate has been observed by expanding the amounts of PSG and LSG parts, while an expansion has been noted by increasing the concentration of tragacanth (TG and citric acid (CA with an increment in floating time. The stearic acid (SA has been used to decrease the lag time because a decrease in density of system was observed. The kinetic analysis showed that the optimized formulation (S4F3 followed zero-order kinetics and power law was found to be best fitted due to its minimum lag time and maximum floating ability. The resemblance of observed and predicted values indicated the validity of derived equations for evaluating the effect of independent variables while kinetic study demonstrated that the applied models are feasible for evaluating and developing float for RNT.

  14. Tunable deformation modes shape contractility in active biopolymer networks

    Science.gov (United States)

    Stam, Samantha; Banerjee, Shiladitya; Weirich, Kim; Freedman, Simon; Dinner, Aaron; Gardel, Margaret

    Biological polymer-based materials remodel under active, molecular motor-driven forces to perform diverse physiological roles, such as force transmission and spatial self-organization. Critical to understanding these biomaterials is elucidating the role of microscopic polymer deformations, such as stretching, bending, buckling, and relative sliding, on material remodeling. Here, we report that the shape of motor-driven deformations can be used to identify microscopic deformation modes and determine how they propagate to longer length scales. In cross-linked actin networks with sufficiently low densities of the motor protein myosin II, microscopic network deformations are predominantly uniaxial, or dominated by sliding. However, longer-wavelength modes are mostly biaxial, or dominated by bending and buckling, indicating that deformations with uniaxial shapes do not propagate across length scales significantly larger than that of individual polymers. As the density of myosin II is increased, biaxial modes dominate on all length scales we examine due to buildup of sufficient stress to produce smaller-wavelength buckling. In contrast, when we construct networks from unipolar, rigid actin bundles, we observe uniaxial, sliding-based contractions on 1 to 100 μm length scales. Our results demonstrate the biopolymer mechanics can be used to tune deformation modes which, in turn, control shape changes in active materials.

  15. Economic assessment of flash co-pyrolysis of short rotation coppice and biopolymer waste streams.

    Science.gov (United States)

    Kuppens, T; Cornelissen, T; Carleer, R; Yperman, J; Schreurs, S; Jans, M; Thewys, T

    2010-12-01

    The disposal problem associated with phytoextraction of farmland polluted with heavy metals by means of willow requires a biomass conversion technique which meets both ecological and economical needs. Combustion and gasification of willow require special and costly flue gas treatment to avoid re-emission of the metals in the atmosphere, whereas flash pyrolysis mainly results in the production of (almost) metal free bio-oil with a relatively high water content. Flash co-pyrolysis of biomass and waste of biopolymers synergistically improves the characteristics of the pyrolysis process: e.g. reduction of the water content of the bio-oil, more bio-oil and less char production and an increase of the HHV of the oil. This research paper investigates the economic consequences of the synergistic effects of flash co-pyrolysis of 1:1 w/w ratio blends of willow and different biopolymer waste streams via cost-benefit analysis and Monte Carlo simulations taking into account uncertainties. In all cases economic opportunities of flash co-pyrolysis of biomass with biopolymer waste are improved compared to flash pyrolysis of pure willow. Of all the biopolymers under investigation, polyhydroxybutyrate (PHB) is the most promising, followed by Eastar, Biopearls, potato starch, polylactic acid (PLA), corn starch and Solanyl in order of decreasing profits. Taking into account uncertainties, flash co-pyrolysis is expected to be cheaper than composting biopolymer waste streams, except for corn starch. If uncertainty increases, composting also becomes more interesting than flash co-pyrolysis for waste of Solanyl. If the investment expenditure is 15% higher in practice than estimated, the preference for flash co-pyrolysis compared to composting biopolymer waste becomes less clear. Only when the system of green current certificates is dismissed, composting clearly is a much cheaper processing technique for disposing of biopolymer waste. Copyright © 2010 Elsevier Ltd. All rights reserved.

  16. In vitro assessment of biopolymer-modified porous silicon microparticles for wound healing applications.

    Science.gov (United States)

    Mori, Michela; Almeida, Patrick V; Cola, Michela; Anselmi, Giulia; Mäkilä, Ermei; Correia, Alexandra; Salonen, Jarno; Hirvonen, Jouni; Caramella, Carla; Santos, Hélder A

    2014-11-01

    The wound healing stands as very complex and dynamic process, aiming the re-establishment of the damaged tissue's integrity and functionality. Thus, there is an emerging need for developing biopolymer-based composites capable of actively promoting cellular proliferation and reconstituting the extracellular matrix. The aims of the present work were to prepare and characterize biopolymer-functionalized porous silicon (PSi) microparticles, resulting in the development of drug delivery microsystems for future applications in wound healing. Thermally hydrocarbonized PSi (THCPSi) microparticles were coated with both chitosan and a mixture of chondroitin sulfate/hyaluronic acid, and subsequently loaded with two antibacterial model drugs, vancomycin and resveratrol. The biopolymer coating, drug loading degree and drug release behavior of the modified PSi microparticles were evaluated in vitro. The results showed that both the biopolymer coating and drug loading of the THCPSi microparticles were successfully achieved. In addition, a sustained release was observed for both the drugs tested. The viability and proliferation profiles of a fibroblast cell line exposed to the modified THCPSi microparticles and the subsequent reactive oxygen species (ROS) production were also evaluated. The cytotoxicity and proliferation results demonstrated less toxicity for the biopolymer-coated THCPSi microparticles at different concentrations and time points comparatively to the uncoated counterparts. The ROS production by the fibroblasts exposed to both uncoated and biopolymer-coated PSi microparticles showed that the modified PSi microparticles did not induce significant ROS production at the concentrations tested. Overall, the biopolymer-based PSi microparticles developed in this study are promising platforms for wound healing applications. Copyright © 2014 Elsevier B.V. All rights reserved.

  17. pH-induced contrast in viscoelasticity imaging of biopolymers

    International Nuclear Information System (INIS)

    Yapp, R D; Insana, M F

    2009-01-01

    Understanding contrast mechanisms and identifying discriminating features is at the heart of diagnostic imaging development. This paper focuses on how pH influences the viscoelastic properties of biopolymers to better understand the effects of extracellular pH on breast tumour elasticity imaging. Extracellular pH is known to decrease as much as 1 pH unit in breast tumours, thus creating a dangerous environment that increases cellular mutatation rates and therapeutic resistance. We used a gelatin hydrogel phantom to isolate the effects of pH on a polymer network with similarities to the extracellular matrix in breast stroma. Using compressive unconfined creep and stress relaxation measurements, we systematically measured the viscoelastic features sensitive to pH by way of time-domain models and complex modulus analysis. These results are used to determine the sensitivity of quasi-static ultrasonic elasticity imaging to pH. We found a strong elastic response of the polymer network to pH, such that the matrix stiffness decreases as pH was reduced; however, the viscous response of the medium to pH was negligible. While physiological features of breast stroma such as proteoglycans and vascular networks are not included in our hydrogel model, observations in this study provide insight into viscoelastic features specific to pH changes in the collagenous stromal network. These observations suggest that the large contrast common in breast tumours with desmoplasia may be reduced under acidic conditions, and that viscoelastic features are unlikely to improve discriminability.

  18. Modelling of proton and metal exchange in the alginate biopolymer.

    Science.gov (United States)

    De Stefano, Concetta; Gianguzza, Antonio; Piazzese, Daniela; Sammartano, Silvio

    2005-10-01

    Acid-base behaviour of a commercial sodium alginate extracted from brown seaweed (Macrocystis pyrifera) has been investigated at different ionic strengths (0.1titration calorimetric data were expressed as a function of the dissociation degree (alpha) using different models (Henderson-Hasselbalch modified, Högfeldt three parameters and linear equations). The dependence on ionic strength of the protonation constants was taken into account by a modified specific interaction theory model. Differences among different media were explained in terms of the interaction between polyanion and metal cations of the supporting electrolytes. Quantitative information on the proton-binding capacity, together with the stabilities of different species formed, is reported. Protonation thermodynamic parameters, at alpha=0.5, are log K H=3.686+/-0.005, DeltaG 0=-21.04+/-0.03 kJ mol(-1), DeltaH 0=4.8+/-0.2 kJ mol(-1) and TDeltaS 0=35.7+/-0.3 kJ mol(-1), at infinite dilution. Protonation enthalpies indicate that the main contribution to proton binding arises from the entropy term. A strict correlation between DeltaG and TDeltaS was found, TDeltaS=-9.5-1.73 DeltaG. Results are reported in light of building up a chemical complexation model of general validity to explain the binding ability of naturally occurring polycarboxylate polymers and biopolymers. Speciation profiles of alginate in the presence of sodium and magnesium ions, naturally occurring cations in natural waters, are also reported.

  19. Electrospun Chitosan-Gelatin Biopolymer Composite Nanofibers for Horseradish Peroxidase Immobilization in a Hydrogen Peroxide Biosensor

    Directory of Open Access Journals (Sweden)

    Siriwan Teepoo

    2017-10-01

    Full Text Available A biosensor based on chitosan-gelatin composite biopolymers nanofibers is found to be effective for the immobilization of horseradish peroxidase to detect hydrogen peroxide. The biopolymer nanofibers were fabricated by an electrospining technique. Upon optimization of synthesis parameters, biopolymers nanofibers, an average of 80 nm in diameter, were obtained and were then modified on the working electrode surface. The effects of the concentration of enzyme, pH, and concentration of the buffer and the working potential on the current response of the nanofibers-modified electrode toward hydrogen peroxide were optimized to obtain the maximal current response. The results found that horseradish peroxidase immobilization on chitosan-gelatin composite biopolymer nanofibers had advantages of fast response, excellent reproducibility, high stability, and showed a linear response to hydrogen peroxide in the concentration range from 0.1 to 1.7 mM with a detection limit of 0.05 mM and exhibited high sensitivity of 44 µA∙mM−1∙cm−2. The developed system was evaluated for analysis of disinfectant samples and showed good agreement between the results obtained by the titration method without significant differences at the 0.05 significance level. The proposed strategy based on chitosan-gelatin composite biopolymer nanofibers for the immobilization of enzymes can be extended for the development of other enzyme-based biosensors.

  20. Chemical Modeling of Acid-Base Properties of Soluble Biopolymers Derived from Municipal Waste Treatment Materials

    Directory of Open Access Journals (Sweden)

    Silvia Tabasso

    2015-02-01

    Full Text Available This work reports a study of the proton-binding capacity of biopolymers obtained from different materials supplied by a municipal biowaste treatment plant located in Northern Italy. One material was the anaerobic fermentation digestate of the urban wastes organic humid fraction. The others were the compost of home and public gardening residues and the compost of the mix of the above residues, digestate and sewage sludge. These materials were hydrolyzed under alkaline conditions to yield the biopolymers by saponification. The biopolymers were characterized by 13C NMR spectroscopy, elemental analysis and potentiometric titration. The titration data were elaborated to attain chemical models for interpretation of the proton-binding capacity of the biopolymers obtaining the acidic sites concentrations and their protonation constants. The results obtained with the models and by NMR spectroscopy were elaborated together in order to better characterize the nature of the macromolecules. The chemical nature of the biopolymers was found dependent upon the nature of the sourcing materials.

  1. Valorisation of CO2-rich off-gases to biopolymers through biotechnological process.

    Science.gov (United States)

    Garcia-Gonzalez, Linsey; De Wever, Heleen

    2017-11-01

    As one of the key enabling technologies, industrial biotechnology has a high potential to tackle harmful CO2 emissions and to turn CO2 into a valuable commodity. So far, experimental work mainly focused on the bioconversion of pure CO2 to chemicals and plastics and little is known about the tolerance of the bioprocesses to the presence of impurities. This work is the first to investigate the impact of real CO2-rich off-gases on autotrophic production of polyhydroxybutyrate. To this end, two-phase heterotrophic-autotrophic fermentation experiments were set up, consisting of heterothrophic cell mass growth using glucose as substrate followed by autotrophic biopolymer production using either pure synthetic CO2 or industrial off-gases sampled at two point sources. The use of real off-gases did not affect the bacterial performance. High biopolymer content (up to 73%) and productivities (up to 0.227 g/lh) were obtained. Characterisation of the polymers showed that all biopolymers had similar properties, independent of the CO2 source. Moreover, the CO2-derived biopolymers' properties were comparable to commercial ones and biopolymers reported in literature, which are all produced from organic carbon sources. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  2. Effect on tomato plant and fruit of the application of biopolymer-oregano essential oil coatings.

    Science.gov (United States)

    Perdones, Ángela; Tur, Núria; Chiralt, Amparo; Vargas, Maria

    2016-10-01

    Oregano essential oil (EO) was incorporated into film-forming dispersions (FFDs) based on biopolymers (chitosan and/or methylcellulose) at two different concentrations. The effect of the application of the FFDs was evaluated on tomato plants (cultivar Micro-Tom) at three different stages of development, and on pre-harvest and postharvest applications on tomato fruit. The application of the FFDs at '3 Leaves' stage caused phytotoxic problems, which were lethal when the EO was applied without biopolymers. Even though plant growth and development were delayed, the total biomass and the crop yield were not affected by biopolymer-EO treatments. When the FFDs were applied in the 'Fruit' stage the pre-harvest application of FFDs had no negative effects. All FFDs containing EO significantly reduced the respiration rate of tomato fruit and diminished weight loss during storage. Moreover, biopolymer-EO FFDs led to a decrease in the fungal decay of tomato fruit inoculated with Rhizopus stolonifer spores, as compared with non-treated tomato fruit and those coated with FFDs without EO. The application of biopolymer-oregano essential oil coatings has been proven to be an effective treatment to control R. stolonifer in tomato fruit. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  3. Encapsulation of lead from hazardous CRT glass wastes using biopolymer cross-linked concrete systems

    International Nuclear Information System (INIS)

    Kim, Daeik; Quinlan, Michael; Yen, Teh Fu

    2009-01-01

    Discarded computer monitors and television sets are identified as hazardous materials due to the high content of lead in their cathode ray tubes (CRTs). Over 98% of lead is found in CRT glass. More than 75% of obsolete electronics including TV and CRT monitors are in storage because appropriate e-waste management and remediation technologies are insufficient. Already an e-waste tsunami is starting to roll across the US and the whole world. Thus, a new technology was developed as an alternative to current disposal methods; this method uses a concrete composite crosslinked with minute amounts of biopolymers and a crosslinking agent. Commercially available microbial biopolymers of xanthan gum and guar gum were used to encapsulate CRT wastes, reducing Pb leachability as measured by standard USEPA methods. In this investigation, the synergistic effect of the crosslinking reaction was observed through blending two different biopolymers or adding a crosslinking agent in biopolymer solution. This CRT-biopolymer-concrete (CBC) composite showed higher compressive strength than the standard concrete and a considerable decrease in lead leachability

  4. Novel biopolymer-coated hydroxyapatite foams for removing heavy-metals from polluted water

    International Nuclear Information System (INIS)

    Vila, M.; Sanchez-Salcedo, S.; Cicuendez, M.; Izquierdo-Barba, I.; Vallet-Regi, Maria

    2011-01-01

    Highlights: → 3D-macroporous biopolymer-coated hydroxyapatite (HA) foams as potential devices for the treatment of heavy metal ions. → HA stable foams coated with biopolymers. → Feasible advance in development of new, easy to handle and low cost water purifying methods. - Abstract: 3D-macroporous biopolymer-coated hydroxyapatite (HA) foams have been developed as potential devices for the treatment of lead, cadmium and copper contamination of consumable waters. These foams have exhibited a fast and effective ion metal immobilization into the HA structure after an in vitro treatment mimicking a serious water contamination case. To improve HA foam stability at contaminated aqueous solutions pH, as well as its handling and shape integrity the 3D-macroporous foams have been coated with biopolymers polycaprolactone (PCL) and gelatine cross-linked with glutaraldehyde (G/Glu). Metal ion immobilization tests have shown higher and fast heavy metals captured as function of hydrophilicity rate of biopolymer used. After an in vitro treatment, foam morphology integrity is guaranteed and the uptake of heavy metal ions rises up to 405 μmol/g in the case of Pb 2+ , 378 μmol/g of Cu 2+ and 316 μmol/g of Cd 2+ . These novel materials promise a feasible advance in development of new, easy to handle and low cost water purifying methods.

  5. Biopolymer nanocomposites: processing, properties, and applications (wiley series on polymer engineering and technology)

    CERN Document Server

    2013-01-01

    Interest in biopolymer nanocomposites is soaring. Not only are they green and sustainable materials, they can also be used to develop a broad range of useful products with special properties, from therapeutics to coatings to packaging materials. With contributions from an international team of leading nanoscientists and materials researchers, this book draws together and reviews the most recent developments and techniques in biopolymer nano-composites. It describes the preparation, processing, properties, and applications of bio- polymer nanocomposites developed from chitin, starch, and cellulose, three renewable resources.Biopolymer Nanocomposites features a logical organization and approach that make it easy for readers to take full advantage of the latest science and technology in designing these materials and developing new products and applications. It begins with a chapter reviewing our current understanding of b...

  6. Enzyme and metabolic engineering for the production of novel biopolymers: crossover of biological and chemical processes.

    Science.gov (United States)

    Matsumoto, Ken'ichiro; Taguchi, Seiichi

    2013-12-01

    The development of synthetic biology has transformed microbes into useful factories for producing valuable polymers and/or their precursors from renewable biomass. Recent progress at the interface of chemistry and biology has enabled the production of a variety of new biopolymers with properties that substantially differ from their petroleum-derived counterparts. This review touches on recent trials and achievements in the field of biopolymer synthesis, including chemo-enzymatically synthesized aliphatic polyesters, wholly biosynthesized lactate-based polyesters, polyhydroxyalkanoates and other unusual bacterially synthesized polyesters. The expanding diversities in structure and the material properties of biopolymers are key for exploring practical applications. The enzyme and metabolic engineering approaches toward this goal are discussed by shedding light on the successful case studies. Copyright © 2013 Elsevier Ltd. All rights reserved.

  7. The cross-linking influence of electromagnetic radiation on water-soluble polyacrylan compositions with biopolymers

    Directory of Open Access Journals (Sweden)

    B. Grabowska

    2009-01-01

    Full Text Available The results of examinations of the cross-linking influence of electromagnetic radiation - in a microwave range – on polyacrylancompositions with biopolymers, are presented in the hereby paper. The cross-linking process of the tested compositions was determined on the basis of the FT-IR spectroscopic methods. It was shown that microwave operations can lead to the formation of new cross-linkedstructures with strong covalent bonds. The adsorption process and formation of active centres in polymer molecules as well as in highsilica sand were found due to microwave radiations. In this process hydroxyl groups (-OH - present in a polymer - and silane groups (Si- O-H - present in a matrix - are mainly taking part. Spectroscopic and strength tests performed for the system: biopolymer binding agent – matrix indicate that the microwave radiation can be applied for hardening moulding sands with biopolymer binders.

  8. CdTe Quantum Dots Embedded in Multidentate Biopolymer Based on Salep: Characterization and Optical Properties

    Directory of Open Access Journals (Sweden)

    Ghasem Rezanejade Bardajee

    2013-01-01

    Full Text Available This paper describes a novel method for surface modification of water soluble CdTe quantum dots (QDs by using poly(acrylic acid grafted onto salep (salep-g-PAA as a biopolymer. As-prepared CdTe-salep-g-PAA QDs were characterized by Fourier transform infrared (FT-IR spectrum, thermogravimetric (TG analysis, and transmission electron microscopy (TEM. The absorption and fluorescence emission spectra were measured to investigate the effect of salep-g-PAA biopolymer on the optical properties of CdTe QDs. The results showed that the optical properties of CdTe QDs were significantly enhanced by using salep-g-PAA-based biopolymer.

  9. Influence of Temperature on Mechanical Properties of Jute/Biopolymer Composites

    DEFF Research Database (Denmark)

    Løvdal, Alexandra Liv Vest; Laursen, Louise Løcke; Løgstrup Andersen, Tom

    2013-01-01

    Biopolymers and natural fibers are receiving wide attention for the potential to have good performance composites with low environmental impact. A current limitation of most biopolymers is however their change in mechanical properties at elevated temperatures. This study investigates the mechanical...... of the fibers. Altogether, the results demonstrate that the thermal sensitivity parameters typically provided for polymers, e.g., the glass transition temperature and the heat deflection temperature, cannot be used as sole parameters for determining the gradual change in mechanical properties of polymers...... properties of two biomass-based polymers, polylactic acid (PLA) and cellulose acetate (CA), as a function of ambient temperature in the range from 5 to 80C. Tests were done for neat polymers and for jute fiber/biopolymer composites. Micromechanical models were applied to back-calculate the reinforcement...

  10. Biosorption of strontium ions from aqueous solution using Ca-alginate biopolymer beads

    International Nuclear Information System (INIS)

    Goek, C.; Aytas, S.; Gerstmann, U.

    2009-01-01

    Biosorption of strontium ions from aqueous solution onto calcium alginate biopolymer beads was investigated in a batch system. Ca-alginate biopolymer beads were prepared from Na-alginate via cross-linking with divalent calcium ions according to the egg box model. Optimum biosorption conditions were determined as a function of initial solution pH, initial Sr concentration, contact time, biomass dosage and temperature. Langmuir, Freundlich and Dubinin-Radushkevich (D-R) models were applied to describe the biosorption isotherm of Sr ions by Ca-alginate biopolymer beads. The thermodynamic parameters (ΔH, ΔS, ΔG) for Sr sorption onto biosorbent were also determined from the temperature dependence. The results indicate that this biosorbent has a good potential for removal of Sr ions from dilute aqueous solution.

  11. Removal of glyphosate herbicide from water using biopolymer membranes.

    Science.gov (United States)

    Carneiro, Rafael T A; Taketa, Thiago B; Gomes Neto, Reginaldo J; Oliveira, Jhones L; Campos, Estefânia V R; de Moraes, Mariana A; da Silva, Camila M G; Beppu, Marisa M; Fraceto, Leonardo F

    2015-03-15

    treat a water sample contaminated with glyphosate. Biopolymer membranes therefore potentially offer a versatile method to eliminate agricultural chemicals from water supplies. Copyright © 2015 Elsevier Ltd. All rights reserved.

  12. Blu-Ray-based micromechanical characterization platform for biopolymer degradation assessment

    DEFF Research Database (Denmark)

    Casci Ceccacci, Andrea; Chen, Ching-Hsiu; Hwu, En-Te

    2017-01-01

    Degradable biopolymers are used as carrier materials in drug delivery devices. A complete understanding of their degradation behaviour is thus crucial in the design of new delivery systems. Here we combine a reliable method, based on spray coated micromechanical resonators and a disposable...... microfluidic chip, to characterize biopolymer degradation under the action of enzymes in controlled flow condition. The sensing platform is based on the mechanics and optics from a Blu-Ray player, which automatically localize individual sensors within the array, and sequentially measure and record...

  13. BIOREFINE-2G — Result In Brief: Novel biopolymers from biorefinery waste-streams

    DEFF Research Database (Denmark)

    Stovicek, Vratislav; Chen, Xiao; Borodina, Irina

    Second generation biorefineries are all about creating value from waste, so it seems only right that the ideal plant should leave nothing behind. With this in mind, the BIOREFINE-2G project has developed novel processes to convert pentose-rich side-streams into biopolymers.......Second generation biorefineries are all about creating value from waste, so it seems only right that the ideal plant should leave nothing behind. With this in mind, the BIOREFINE-2G project has developed novel processes to convert pentose-rich side-streams into biopolymers....

  14. Parallelized system for biopolymer degradation studies through automated microresonator measurement in liquid flow

    DEFF Research Database (Denmark)

    Casci Ceccacci, Andrea; Morelli, Lidia; Bosco, Filippo

    2015-01-01

    setup unit, the system allows high-throughput measurements of resonance frequency over microresonator arrays under controlled flow conditions. We here demonstrate the acquisition of statistical data on biopolymer films degradation under enzymatic reaction over a large sample of micromechanical......In this work we present a novel automated system which allows the study of enzymatic degradation of biopolymer films coated on micromechanical resonators. The system combines an optical readout based on Blu-Ray technology with a software-controlled scanning mechanism. Integrated with a microfluidic...

  15. The Influence of Biopolym FTZ on the Content of Nitrogen Compounds in Rumen

    Directory of Open Access Journals (Sweden)

    Eva Petrášková

    2010-05-01

    Full Text Available The aim of this study was to verify the effect of Biopolym FZT on the crude protein in the ruminal content. The experiment was conducted in laboratory conditions. Rumen content was removed from the Holstein breed cow fitted with ruminal fistula. The hydrolyzed brown seaweed was added to the samples of the ruminal content. After incubation of the samples the crude protein content was determined. In experiments with solid ruminal contents positive effects of Biopolym on the crude protein content was shown. The best results were achieved at the dilution of 1:2000.

  16. Incorporation of zinc oxide to dispersions of biopolymers and release of the metallic ion in vitro

    International Nuclear Information System (INIS)

    Barreto, Marina S.R.; Ferreira, Willian H.; Andrade, Cristina T.

    2015-01-01

    Zinc oxide (ZnO) nanoparticles, obtained from a commercial product, were dispersed in different biopolymers, to be added to piglet feeds. The resulting products, prepared with sodium alginate (SA), chitosan (CH) and low methoxyl pectin (LMP) were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The release of Zn"2"+ was investigated under simulated conditions of the gastrointestinal tract of piglets, and analyzed by atomic absorption spectroscopy (AA). The results showed that the structural factors, which have influence on the biopolymer/ZnO interactions, govern the behavior of Zn"2"+ release. (author)

  17. Biopolymer-Based Nanoparticles for Drug/Gene Delivery and Tissue Engineering

    Science.gov (United States)

    Nitta, Sachiko Kaihara; Numata, Keiji

    2013-01-01

    There has been a great interest in application of nanoparticles as biomaterials for delivery of therapeutic molecules such as drugs and genes, and for tissue engineering. In particular, biopolymers are suitable materials as nanoparticles for clinical application due to their versatile traits, including biocompatibility, biodegradability and low immunogenicity. Biopolymers are polymers that are produced from living organisms, which are classified in three groups: polysaccharides, proteins and nucleic acids. It is important to control particle size, charge, morphology of surface and release rate of loaded molecules to use biopolymer-based nanoparticles as drug/gene delivery carriers. To obtain a nano-carrier for therapeutic purposes, a variety of materials and preparation process has been attempted. This review focuses on fabrication of biocompatible nanoparticles consisting of biopolymers such as protein (silk, collagen, gelatin, β-casein, zein and albumin), protein-mimicked polypeptides and polysaccharides (chitosan, alginate, pullulan, starch and heparin). The effects of the nature of the materials and the fabrication process on the characteristics of the nanoparticles are described. In addition, their application as delivery carriers of therapeutic drugs and genes and biomaterials for tissue engineering are also reviewed. PMID:23344060

  18. Biopolymer-Based Nanoparticles for Drug/Gene Delivery and Tissue Engineering

    Directory of Open Access Journals (Sweden)

    Keiji Numata

    2013-01-01

    Full Text Available There has been a great interest in application of nanoparticles as biomaterials for delivery of therapeutic molecules such as drugs and genes, and for tissue engineering. In particular, biopolymers are suitable materials as nanoparticles for clinical application due to their versatile traits, including biocompatibility, biodegradability and low immunogenicity. Biopolymers are polymers that are produced from living organisms, which are classified in three groups: polysaccharides, proteins and nucleic acids. It is important to control particle size, charge, morphology of surface and release rate of loaded molecules to use biopolymer-based nanoparticles as drug/gene delivery carriers. To obtain a nano-carrier for therapeutic purposes, a variety of materials and preparation process has been attempted. This review focuses on fabrication of biocompatible nanoparticles consisting of biopolymers such as protein (silk, collagen, gelatin, β-casein, zein and albumin, protein-mimicked polypeptides and polysaccharides (chitosan, alginate, pullulan, starch and heparin. The effects of the nature of the materials and the fabrication process on the characteristics of the nanoparticles are described. In addition, their application as delivery carriers of therapeutic drugs and genes and biomaterials for tissue engineering are also reviewed.

  19. A review of combined experimental and computational procedures for assessing biopolymer structure-process-property relationships.

    Science.gov (United States)

    Gronau, Greta; Krishnaji, Sreevidhya T; Kinahan, Michelle E; Giesa, Tristan; Wong, Joyce Y; Kaplan, David L; Buehler, Markus J

    2012-11-01

    Tailored biomaterials with tunable functional properties are desirable for many applications ranging from drug delivery to regenerative medicine. To improve the predictability of biopolymer materials functionality, multiple design parameters need to be considered, along with appropriate models. In this article we review the state of the art of synthesis and processing related to the design of biopolymers, with an emphasis on the integration of bottom-up computational modeling in the design process. We consider three prominent examples of well-studied biopolymer materials - elastin, silk, and collagen - and assess their hierarchical structure, intriguing functional properties and categorize existing approaches to study these materials. We find that an integrated design approach in which both experiments and computational modeling are used has rarely been applied for these materials due to difficulties in relating insights gained on different length- and time-scales. In this context, multiscale engineering offers a powerful means to accelerate the biomaterials design process for the development of tailored materials that suit the needs posed by the various applications. The combined use of experimental and computational tools has a very broad applicability not only in the field of biopolymers, but can be exploited to tailor the properties of other polymers and composite materials in general. Copyright © 2012 Elsevier Ltd. All rights reserved.

  20. A review of combined experimental and computational procedures for assessing biopolymer structure–process–property relationships

    Science.gov (United States)

    Gronau, Greta; Krishnaji, Sreevidhya T.; Kinahan, Michelle E.; Giesa, Tristan; Wong, Joyce Y.; Kaplan, David L.; Buehler, Markus J.

    2013-01-01

    Tailored biomaterials with tunable functional properties are desirable for many applications ranging from drug delivery to regenerative medicine. To improve the predictability of biopolymer materials functionality, multiple design parameters need to be considered, along with appropriate models. In this article we review the state of the art of synthesis and processing related to the design of biopolymers, with an emphasis on the integration of bottom-up computational modeling in the design process. We consider three prominent examples of well-studied biopolymer materials – elastin, silk, and collagen – and assess their hierarchical structure, intriguing functional properties and categorize existing approaches to study these materials. We find that an integrated design approach in which both experiments and computational modeling are used has rarely been applied for these materials due to difficulties in relating insights gained on different length- and time-scales. In this context, multiscale engineering offers a powerful means to accelerate the biomaterials design process for the development of tailored materials that suit the needs posed by the various applications. The combined use of experimental and computational tools has a very broad applicability not only in the field of biopolymers, but can be exploited to tailor the properties of other polymers and composite materials in general. PMID:22938765

  1. The Effect of Sodium Hydroxide on Drag Reduction using a Biopolymer.

    Directory of Open Access Journals (Sweden)

    Singh Harvin Kaur A/P Gurchran

    2014-07-01

    Full Text Available Drag reduction is observed as reduced frictional pressure losses under turbulent flow conditions and hence, substantially increases the flowrate of the fluid. Practical application includes water flooding system, pipeline transport and drainage system. Drag reduction agent, such as polymers, can be introduced to increase the flowrate of water flowing, reducing the water accumulation in the system and subsequently lesser possibility of heavy flooding. Currently used polymer as drag reduction agents is carboxymethylcellulose, to name one. This is a synthetic polymer which will seep into the ground and further harm our environment in excessive use of accumulation. A more environmentally-friendly drag reduction agent, such as the polymer derived from natural sources or biopolymer, is then required for such purpose. As opposed to the synthetic polymers, the potential of biopolymers as drag reduction agents, especially those derived from a local plant source, are not extensively explored. The drag reduction of a polymer produced from a local plant source within the turbulent regime will be explored and assessed in this study using a rheometer where a reduced a torque produced can be perceived as a reduction of drag. The cellulose powder was converted to carboxymethylcellulose (CMC by etherification process using sodium monochloroacetate and sodium hydroxide. The carboxymethylation reaction then was optimized against concentration of NaOH. The research is structured to focus on producing the biopolymer and also assess the drag reduction ability of the biopolymer produced against concentration of sodium hydroxide.

  2. Single walled carbon nanotubes with functionally adsorbed biopolymers for use as chemical sensors

    Science.gov (United States)

    Johnson, Jr., Alan T

    2013-12-17

    Chemical field effect sensors comprising nanotube field effect devices having biopolymers such as single stranded DNA or RNA functionally adsorbed to the nanotubes are provided. Also included are arrays comprising the sensors and methods of using the devices to detect volatile compounds.

  3. Ionic Liquid Microemullsions, Templates for Directing Morphology of Cellulose Biopolymer Nanoparticles (Briefing Charts)

    Science.gov (United States)

    2015-08-19

    Charts 3. DATES COVERED (From - To) July 2015-August 2015 4. TITLE AND SUBTITLE Ionic Liquid Microemullsions, Templates for Directing Morphology of...unlimited AFRL Public Affairs Clearance No. TBD Ionic Liquid Microemullsions, Templates for Directing Morphology of Cellulose Biopolymer...AFRL Public Affairs Clearance No. 15438 Outline • Background on Cellulose and Ionic Liquids • Materials and Methods • Results: Designing an IL

  4. Biopolymers Regulate Silver Nanoparticle under Microwave Irradiation for Effective Antibacterial and Antibiofilm Activities.

    Directory of Open Access Journals (Sweden)

    Palaniyandi Velusamy

    Full Text Available In the current study, facile synthesis of carboxymethyl cellulose (CMC and sodium alginate capped silver nanoparticles (AgNPs was examined using microwave radiation and aniline as a reducing agent. The biopolymer matrix embedded nanoparticles were synthesized under various experimental conditions using different concentrations of biopolymer (0.5, 1, 1.5, 2%, volumes of reducing agent (50, 100, 150 μL, and duration of heat treatment (30 s to 240 s. The synthesized nanoparticles were analyzed by scanning electron microscopy, UV-Vis spectroscopy, X-ray diffraction, and Fourier transform infrared spectroscopy for identification of AgNPs synthesis, crystal nature, shape, size, and type of capping action. In addition, the significant antibacterial efficacy and antibiofilm activity of biopolymer capped AgNPs were demonstrated against different bacterial strains, Staphylococcus aureus MTCC 740 and Escherichia coli MTCC 9492. These results confirmed the potential for production of biopolymer capped AgNPs grown under microwave irradiation, which can be used for industrial and biomedical applications.

  5. Biopolymer films to control fusarium dry rot and their application to preserve potato tubers

    Science.gov (United States)

    Films were cast using sodium alginate (NaAlg), high molecular weight (HMW) chitosan, and low molecular weight (LMW) chitosan as film forming biopolymers. Fludioxonil (Fl) at 1% concentration was used as fungicide. Thermal stability, mechanical, and water sorption properties of the films were examine...

  6. A novel method of providing a library of n-mers or biopolymers

    DEFF Research Database (Denmark)

    2012-01-01

    The present invention relates to a method of providing a library of n-mer sequences, wherein the library is composed of an n-mer sequence. Also the invention concerns a method of providing a library of biopolymer sequences having one or more n-mers in common. Further provided are specific primers...

  7. Small Strain Topological Effects of Biopolymer Networks with Rigid Cross-Links

    NARCIS (Netherlands)

    Zagar, G.; Onck, P. R.; Van der Giessen, E.; Garikipati, K; Arruda, EM

    2010-01-01

    Networks of cross-linked filamentous biopolymers form topological structures characterized by L, T and X cross-link types of connectivity 2, 3 and 4, respectively. The distribution of cross-links over these three types proofs to be very important for the initial elastic shear stiffness of isotropic

  8. BIOLOGICAL NANOPORES FOR BIOPOLYMER SENSING AND SEQUENCING BASED ON FRAC ACTINOPORIN

    NARCIS (Netherlands)

    Maglia, Giovanni; Wloka, Carsten; Mutter, Natalie Lisa; Soskine, Misha; Huang, Gang

    2018-01-01

    The invention relates generally to the field of nanopores and the use thereof in various applications, such as analysis of biopolymer s and macromolecules, typically by making electrical measurements during translocation through a nanopores. Provided is a system comprising a funnel- shaped

  9. Models for stiffening in cross-linked biopolymer networks : A comparative study

    NARCIS (Netherlands)

    van Dillen, T.; Onck, P. R.; Van der Giessen, E.

    In a recent publication, we studied the mechanical stiffening behavior in two-dimensional (2D) cross-linked networks of semiflexible biopolymer filaments under simple shear [Onck, P.R., Koeman, T., Van Dillen, T., Van der Giessen, E., 2005. Alternative explanation of stiffening in cross-linked

  10. Polyhydroxybutyrate (PHB) Synthesis by Spirulina sp. LEB 18 Using Biopolymer Extraction Waste.

    Science.gov (United States)

    da Silva, Cleber Klasener; Costa, Jorge Alberto Vieira; de Morais, Michele Greque

    2018-01-20

    The reuse of waste as well as the production of biodegradable compounds has for years been the object of studies and of global interest as a way to reduce the environmental impact generated by unsustainable exploratory processes. The conversion of linear processes into cyclical processes has environmental and economic advantages, reducing waste deposition and reducing costs. The objective of this work was to use biopolymer extraction waste in the cultivation of Spirulina sp. LEB 18, for the cyclic process of polyhydroxybutyrate (PHB) synthesis. Concentrations of 10, 15, 20, 25, and 30% (v/v) of biopolymer extraction waste were tested. For comparison, two assays were used without addition of waste, Zarrouk (SZ) and modified Zarrouk (ZM), with reduction of nitrogen. The assays were carried out in triplicate and evaluated for the production of microalgal biomass and PHB. The tests with addition of waste presented a biomass production statistically equal to ZM (0.79 g L -1 ) (p PHB in the assay containing 25% of waste was higher when compared to the other cultivations, obtaining 10.6% (w/w) of biopolymer. From the results obtained, it is affirmed that the use of PHB extraction waste in the microalgal cultivation, aiming at the synthesis of biopolymers, can occur in a cyclic process, reducing process costs and the deposition of waste, thus favoring the preservation of the environment.

  11. Overview of biopolymers as carriers of antiphlogistic agents for treatment of diverse ocular inflammations.

    Science.gov (United States)

    Sharma, Anil Kumar; Arya, Amit; Sahoo, Pravat Kumar; Majumdar, Dipak Kanti

    2016-10-01

    Inflammation of the eye is a usual clinical condition that can implicate any part of the eye. The nomenclature of variety of such inflammations is based on the ocular part involved. These diseases may jeopardize normal functioning of the eye on progression. In general, corticosteroids, antihistamines, mast cell stabilizers and non-steroidal anti-inflammatory drugs (NSAIDs) are used to treat inflammatory diseases/disorders of the eye. There have been several attempts via different approaches of drug delivery to overcome the low ocular bioavailability resulting from shorter ocular residence time. The features like safety, ease of elimination and ability to sustain drug release have led to application of biopolymers in ocular therapeutics. Numerous polymers of natural origin such as gelatin, collagen, chitosan, albumin, hyaluronic acid, alginates etc. have been successfully employed for preparation of different ocular dosage forms. Chitosan is the most explored biopolymer amongst natural biopolymers because of its inherent characteristics. The emergence of synthetic biopolymers (like PVP, PACA, PCL, POE, polyanhydrides, PLA, PGA and PLGA) has also added new dimensions to the drug delivery strategies meant for treatment of ophthalmic inflammations. The current review is an endeavor to describe the utility of a variety of biomaterials/polymers based drug delivery systems as carrier for anti-inflammatory drugs in ophthalmic therapeutics. Copyright © 2016 Elsevier B.V. All rights reserved.

  12. Enzymatic functionalization of cork surface with antimicrobial hybrid biopolymer/silver nanoparticles.

    Science.gov (United States)

    Francesko, Antonio; Blandón, Lucas; Vázquez, Mario; Petkova, Petya; Morató, Jordi; Pfeifer, Annett; Heinze, Thomas; Mendoza, Ernest; Tzanov, Tzanko

    2015-05-13

    Laccase-assisted assembling of hybrid biopolymer-silver nanoparticles and cork matrices into an antimicrobial material with potential for water remediation is herein described. Amino-functional biopolymers were first used as doping agents to stabilize concentrated colloidal dispersions of silver nanoparticles (AgNP), additionally providing the particles with functionalities for covalent immobilization onto cork to impart a durable antibacterial effect. The solvent-free AgNP synthesis by chemical reduction was carried out in the presence of chitosan (CS) or 6-deoxy-6-(ω-aminoethyl) aminocellulose (AC), leading to simultaneous AgNP biofunctionalization. This approach resulted in concentrated hybrid NP dispersion stable to aggregation and with hydrodynamic radius of particles of about 250 nm. Moreover, laccase enabled coupling between the phenolic groups in cork and amino moieties in the biopolymer-doped AgNP for permanent modification of the material. The antibacterial efficiency of the functionalized cork matrices, aimed as adsorbents for wastewater treatment, was evaluated against Escherichia coli and Staphylococcus aureus during 5 days in conditions mimicking those in constructed wetlands. Both intrinsically antimicrobial CS and AC contributed to the bactericidal effect of the enzymatically grafted on cork AgNP. In contrast, unmodified AgNP were easily washed off from the material, confirming that the biopolymers potentiated a durable antibacterial functionalization of the cork matrices.

  13. A novel method for biopolymer surface nanostructuring by platinum deposition and subsequent thermal annealing

    Czech Academy of Sciences Publication Activity Database

    Slepička, P.; Juřík, P.; Kolská, Z.; Malinský, Petr; Macková, Anna; Michaljaničová, I.; Švorčík, V.

    2012-01-01

    Roč. 7, č. 671 (2012), s. 1-6 ISSN 1931-7573 R&D Projects: GA ČR(CZ) GBP108/12/G108 Institutional support: RVO:61389005 Keywords : nanopattering * surface morphology * biopolymer * platinum sputtering * thermal annealing Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 2.524, year: 2012

  14. Hybrid waste filler filled bio-polymer foam composites for sound absorbent materials

    Science.gov (United States)

    Rus, Anika Zafiah M.; Azahari, M. Shafiq M.; Kormin, Shaharuddin; Soon, Leong Bong; Zaliran, M. Taufiq; Ahraz Sadrina M. F., L.

    2017-09-01

    Sound absorption materials are one of the major requirements in many industries with regards to the sound insulation developed should be efficient to reduce sound. This is also important to contribute in economically ways of producing sound absorbing materials which is cheaper and user friendly. Thus, in this research, the sound absorbent properties of bio-polymer foam filled with hybrid fillers of wood dust and waste tire rubber has been investigated. Waste cooking oil from crisp industries was converted into bio-monomer, filled with different proportion ratio of fillers and fabricated into bio-polymer foam composite. Two fabrication methods is applied which is the Close Mold Method (CMM) and Open Mold Method (OMM). A total of four bio-polymer foam composite samples were produce for each method used. The percentage of hybrid fillers; mixture of wood dust and waste tire rubber of 2.5 %, 5.0%, 7.5% and 10% weight to weight ration with bio-monomer. The sound absorption of the bio-polymer foam composites samples were tested by using the impedance tube test according to the ASTM E-1050 and Scanning Electron Microscope to determine the morphology and porosity of the samples. The sound absorption coefficient (α) at different frequency range revealed that the polymer foam of 10.0 % hybrid fillers shows highest α of 0.963. The highest hybrid filler loading contributing to smallest pore sizes but highest interconnected pores. This also revealed that when highly porous material is exposed to incident sound waves, the air molecules at the surface of the material and within the pores of the material are forced to vibrate and loses some of their original energy. This is concluded that the suitability of bio-polymer foam filled with hybrid fillers to be used in acoustic application of automotive components such as dashboards, door panels, cushion and etc.

  15. Boletus edulis biologically active biopolymers induce cell cycle arrest in human colon adenocarcinoma cells.

    Science.gov (United States)

    Lemieszek, Marta Kinga; Cardoso, Claudia; Ferreira Milheiro Nunes, Fernando Hermínio; Ramos Novo Amorim de Barros, Ana Isabel; Marques, Guilhermina; Pożarowski, Piotr; Rzeski, Wojciech

    2013-04-25

    The use of biologically active compounds isolated from edible mushrooms against cancer raises global interest. Anticancer properties are mainly attributed to biopolymers including mainly polysaccharides, polysaccharopeptides, polysaccharide proteins, glycoproteins and proteins. In spite of the fact that Boletus edulis is one of the widely occurring and most consumed edible mushrooms, antitumor biopolymers isolated from it have not been exactly defined and studied so far. The present study is an attempt to extend this knowledge on molecular mechanisms of their anticancer action. The mushroom biopolymers (polysaccharides and glycoproteins) were extracted with hot water and purified by anion-exchange chromatography. The antiproliferative activity in human colon adenocarcinoma cells (LS180) was screened by means of MTT and BrdU assays. At the same time fractions' cytotoxicity was examined on the human colon epithelial cells (CCD 841 CoTr) by means of the LDH assay. Flow cytometry and Western blotting were applied to cell cycle analysis and protein expression involved in anticancer activity of the selected biopolymer fraction. In vitro studies have shown that fractions isolated from Boletus edulis were not toxic against normal colon epithelial cells and in the same concentration range elicited a very prominent antiproliferative effect in colon cancer cells. The best results were obtained in the case of the fraction designated as BE3. The tested compound inhibited cancer cell proliferation which was accompanied by cell cycle arrest in the G0/G1-phase. Growth inhibition was associated with modulation of the p16/cyclin D1/CDK4-6/pRb pathway, an aberration of which is a critical step in the development of many human cancers including colon cancer. Our results indicate that a biopolymer BE3 from Boletus edulis possesses anticancer potential and may provide a new therapeutic/preventive option in colon cancer chemoprevention.

  16. Smart swelling biopolymer microparticles by a microfluidic approach: synthesis, in situ encapsulation and controlled release.

    Science.gov (United States)

    Fang, Aiping; Cathala, Bernard

    2011-01-01

    This paper reports a microfluidic synthesis of biopolymer microparticles aiming at smart swelling. Monodisperse aqueous emulsion droplets comprising biopolymer and its cross-linking agent were formed in mineral oil and solidified in the winding microfluidic channels by in situ chaotic mixing, which resulted in internal chemical gelation for hydrogels. The achievement of pectin microparticles from in situ mixing pectin with its cross-linking agent, calcium ions, successfully demonstrates the reliability of this microfluidic synthesis approach. In order to achieve hydrogels with smart swelling, the following parameters and their impacts on the swelling behaviour, stability and morphology of microparticles were investigated: (1) the type of biopolymers (alginate or mixture of alginate and carboxymethylcellulose, A-CMC); (2) rapid mixing; (3) concentration and type of cross-linking agent. Superabsorbent microparticles were obtained from A-CMC mixture by using ferric chloride as an additional external cross-linking agent. The in situ encapsulation of a model protein, bovine serum albumin (BSA), was also carried out. As a potential protein drug-delivery system, the BSA release behaviours of the biopolymer particles were studied in simulated gastric and intestinal fluids. Compared with alginate and A-CMC microparticles cross-linked with calcium ions, A-CMC microparticles cross-linked with both calcium and ferric ions demonstrate a significantly delayed release. The controllable release profile, the facile encapsulation as well as their biocompatibility, biodegradability, mucoadhesiveness render this microfluidic approach promising in achieving biopolymer microparticles as protein drug carrier for site-specific release. Copyright © 2010 Elsevier B.V. All rights reserved.

  17. Biopolymers coated superparamagnetic Nickel Ferrites: Enhanced biocompatibility and MR imaging probe for breast cancer

    Energy Technology Data Exchange (ETDEWEB)

    Bano, Shazia, E-mail: shaziaphy@gmail.com [Department of Physics, The Islamia University of Bahawalpur (Pakistan); Zafar, Tayyaba [Department of Physics, The Islamia University of Bahawalpur (Pakistan); Akhtar, Shahnaz [Department of Pharmacy, The Islamia University of Bahawalpur (Pakistan); Buzdar, Saeed Ahmed [Department of Physics, The Islamia University of Bahawalpur (Pakistan); Waraich, Mustansar Mahmood, E-mail: mustansarwaraich@gmail.com [Quaid-e-Azam Medical College B.V. Hospital, Bahawalpur (Pakistan); Afzal, Muhammad [Department of Physics, The Islamia University of Bahawalpur (Pakistan)

    2016-11-01

    We report evidence for the promising application of bovine serum albumin (BSA), chitosan (CS) or carboxymethyl cellulose (CMC) coated NiFe{sub 2}O{sub 4} cores for improved biocompatibility and enhanced T2 relaxivity, through a single combinatorial approach. Pure nickel-ferrite nano cores (NFs) successfully synthesized by thermolysis, were immobilize with BSA, CS or CMC layer employing a simple cross linking procedure to avoid any significant influence of these biopolymers on the morphology and crystal structure of the cores. Phase, morphology, magnetic hysteresis and surface chemistry were characterized by X-ray diffraction (XRD), Field emission scanning electron microscopy (FE-SEM), vibrating sample magnetometer (VSM) and Fourier transform infrared (FTIR) spectroscopy. The preliminary haemolysis and cell viability experiments show that biopolymers conjugation mitigates the haemolytic effect of the NFs on erythrocytes as the haemolytic index is less than 2% and cell viability is up to 100%, when normalized with the nontreated cells. The relaxivity value of coated NFs is 351±2.6 when compared to 84±0.22 of NFs without biopolymer conjugation. The results demonstrate that BSA, CS or CMC covering on NFs provide a single combinatorial approach to improve the biocompatibility and enhance the relaxivity value. Thus addressing the current challenge of the same with very good contrast for targeting MCF-7 without any further vectorization. - Highlights: • A single combinatorial system for the promising application of biopolymers coated NiFe{sub 2}O{sub 4} cores. • Immobilization of a thin layer of three different biopolymers via a simple approach. • Excellent MR contrast enhancement and targeting of MCF-7 without any further vectorization.

  18. Electrical study on Carboxymethyl Cellulose-Polyvinyl alcohol based bio-polymer blend electrolytes

    Science.gov (United States)

    Saadiah, M. A.; Samsudin, A. S.

    2018-04-01

    The present work deals with the formulation of bio-materials namely carboxymethyl cellulose (CMC) and polyvinyl alcohol (PVA) for bio-polymer blend electrolytes (BBEs) system which was successfully carried out with different ratio of polymer blend. The biopolymer blend was prepared via economical & classical technique that is solution casting technique and was characterized by using impedance spectroscopy (EIS). The ionic conductivity was achieved to optimum value 9.12 x 10-6 S/cm at room temperature for sample containing ratio 80:20 of CMC:PVA. The highest conducting sample was found to obey the Arrhenius behaviour with a function of temperature. The electrical properties were analyzed using complex permittivity ε* and complex electrical modulus M* for BBEs system and it shows the non-Debye characteristics where no single relaxation time has observed.

  19. Extraction of alginate biopolymer present in marine alga sargassum filipendula and bioadsorption of metallic ions

    Directory of Open Access Journals (Sweden)

    Sirlei Jaiana Kleinübing

    2013-04-01

    Full Text Available This paper studies the bioadsorption of Pb2+, Cu2+, Cd2+ and Zn2+ ions by marine alga Sargassum filipendula and by the alginate biopolymer extracted from this alga. The objective is to evaluate the importance of this biopolymer in removing different metallic ions by the marine alga S. filipendula. In the equilibrium study, the same affinity order was observed for both bioadsorbents: Pb2+ > Cu2+ > Zn2+ > Cd2+. For Pb2+ and Cu2+ ions when the alginate is isolated and acting as bioadsorbents, adsorption capacities greater than those found for the alga were observed, indicating that it is the main component responsible for the removal of metallic ions. For Zn2+ and Cd2+ ions, greater bioadsorption capacities were observed for the alga, indicating that other functional groups of the alga, such as sulfates and amino, are also important in the bioadsorption of these ions.

  20. Biopolymers production with carbon source from the wastes of a beer brewery industry

    Science.gov (United States)

    Wong, Phoeby Ai Ling

    The main purpose of this study was to assess the potential and feasibility of malt wastes, and other food wastes, such as soy wastes, ice-cream wastes, confectionery wastes, vinegar wastes, milk waste and sesame oil, in the induction of biosynthesis of PHA, in the cellular assembly of novel PHA with improved physical and chemical properties, and in the reduction of the cost of PHA production. In the first part of the experiments, a specific culture of Alcaligenes latus DSM 1124 was selected to ferment several types of food wastes as carbon sources into biopolymers. In addition, the biopolymer production, by way of using malt waste, of microorganisms from municipal activated sludge was also investigated. In the second part, the experiments focused on the synthesis of biopolymer with a higher molecular mass via the bacterial strain, which was selected and isolated from sesame oil, identified as Staphylococcus epidermidis . Molecular weight and molecular weight distribution of PHB were studied by GPC. Molecular weight of PHB produced from various types of food wastes by Alcaligenes latus was higher than using synthetic sucrose medium as nutrient, however, it resulted in the reverse by Staphylococcus epidermidis. Thermal properties of biopolymers were studied by DSC and TG. Using malt wastes as nutrients by Alcaligenes latus gave a higher melting temperature. Using sucrose, confectionery and sesame oil as nutrients by Staphylococcus epidermidis gave higher melting temperature. Optimization was carried out for the recovery of microbial PHB from Alcaligenes latus. Results showed that molecular weight can be controlled by changing the hypochlorite concentration, the ratio of chloroform to hypochlorite solution and the extraction time. In addition, the determination of PHB content by thermogravimetric analysis method with wet cell was the first report in our study. (Abstract shortened by UMI.)

  1. Wetting of biopolymer coatings: contact angle kinetics and image analysis investigation.

    Science.gov (United States)

    Farris, Stefano; Introzzi, Laura; Biagioni, Paolo; Holz, Torsten; Schiraldi, Alberto; Piergiovanni, Luciano

    2011-06-21

    The surface wetting of five biopolymers, used as coating materials for a plastic film, was monitored over a span of 8 min by means of the optical contact angle technique. Because most of the total variation was observed to occur during the first 60 s, we decided to focus on this curtailed temporal window. Initial contact angle values (θ(0)) ranged from ∼91° for chitosan to ∼30° for pullulan. However, the water drop profile began to change immediately following drop deposition for all biocoatings, confirming that the concept of water contact angle equilibrium is not applicable to most biopolymers. First, a three-parameter decay equation [θ(t) = θ(0) exp(kt(n))] was fit to the experimental contact angle data to describe the kinetics of the contact angle change for each biocoating. Interestingly, the k constant correlated well with the contact angle evolution rate and the n exponent seemed to be somehow linked to the physicochemical phenomena underlying the overall kinetics process. Second, to achieve a reliable description of droplet evolution, the contact angle (CA) analysis was coupled with image analysis (IA) through a combined geometric/trigonometric approach. Absorption and spreading were the key factors governing the overall mechanism of surface wetting during the 60 s analysis, although the individual quantification of both phenomena demonstrated that spreading provided the largest contribution for all biopolymers, with the only exception of gelatin, which showed two quasi-equivalent and counterbalancing effects. The possible correlation between these two phenomena and the topography of the biopolymer surfaces are then discussed on the basis of atomic force microscopy analyses. © 2011 American Chemical Society

  2. Overview of biopolymers as carriers of antiphlogistic agents for treatment of diverse ocular inflammations

    International Nuclear Information System (INIS)

    Sharma, Anil Kumar; Arya, Amit; Sahoo, Pravat Kumar; Majumdar, Dipak Kanti

    2016-01-01

    Inflammation of the eye is a usual clinical condition that can implicate any part of the eye. The nomenclature of variety of such inflammations is based on the ocular part involved. These diseases may jeopardize normal functioning of the eye on progression. In general, corticosteroids, antihistamines, mast cell stabilizers and non-steroidal anti-inflammatory drugs (NSAIDs) are used to treat inflammatory diseases/disorders of the eye. There have been several attempts via different approaches of drug delivery to overcome the low ocular bioavailability resulting from shorter ocular residence time. The features like safety, ease of elimination and ability to sustain drug release have led to application of biopolymers in ocular therapeutics. Numerous polymers of natural origin such as gelatin, collagen, chitosan, albumin, hyaluronic acid, alginates etc. have been successfully employed for preparation of different ocular dosage forms. Chitosan is the most explored biopolymer amongst natural biopolymers because of its inherent characteristics. The emergence of synthetic biopolymers (like PVP, PACA, PCL, POE, polyanhydrides, PLA, PGA and PLGA) has also added new dimensions to the drug delivery strategies meant for treatment of ophthalmic inflammations. The current review is an endeavor to describe the utility of a variety of biomaterials/polymers based drug delivery systems as carrier for anti-inflammatory drugs in ophthalmic therapeutics. - Highlights: • Numerous eye inflammations pose troubles in vision functions. • Low bioavailability by conventional drug delivery systems due to eye constraints • Drug carriers ensuring improved bioavailability to the eye are need of the hour. • Chitosan - most explored amongst all biomaterials for ocular delivery. • Emergence of novel synthetic carriers in ophthalmology

  3. Biopolymer strategy for the treatment of Wilson´s disease

    Czech Academy of Sciences Publication Activity Database

    Vetrík, Miroslav; Mattová, J.; Macková, Hana; Kučka, Jan; Poučková, P.; Kukačková, Olivia; Brus, Jiří; Eigner-Henke, S.; Sedláček, Ondřej; Šefc, L.; Štěpánek, Petr; Hrubý, Martin

    2018-01-01

    Roč. 273, 10 March (2018), s. 131-138 ISSN 0168-3659 R&D Projects: GA ČR(CZ) GA16-02870S; GA MZd(CZ) NV15-25781A; GA MŠk(CZ) LM2015064; GA MŠk(CZ) LO1507 Institutional support: RVO:61389013 Keywords : Wilson's disease * copper chelators * biopolymers Subject RIV: CD - Macromolecular Chemistry OBOR OECD: Polymer science Impact factor: 7.786, year: 2016

  4. Exploring the energy landscape of biopolymers using single molecule force spectroscopy and molecular simulations

    OpenAIRE

    Hyeon, Changbong

    2010-01-01

    In recent years, single molecule force techniques have opened a new avenue to decipher the folding landscapes of biopolymers by allowing us to watch and manipulate the dynamics of individual proteins and nucleic acids. In single molecule force experiments, quantitative analyses of measurements employing sound theoretical models and molecular simulations play central role more than any other field. With a brief description of basic theories for force mechanics and molecular simulation techniqu...

  5. Overview of biopolymers as carriers of antiphlogistic agents for treatment of diverse ocular inflammations

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, Anil Kumar, E-mail: sharmarahul2004@gmail.com [Delhi Institute of Pharmaceutical Sciences and Research, Formerly College of Pharmacy, University of Delhi, Pushp Vihar, Sector III, New Delhi 110017,India (India); Arya, Amit; Sahoo, Pravat Kumar [Delhi Institute of Pharmaceutical Sciences and Research, Formerly College of Pharmacy, University of Delhi, Pushp Vihar, Sector III, New Delhi 110017,India (India); Majumdar, Dipak Kanti [School of Pharmaceutical Sciences, Apeejay Stya University, Sohna-Palwal Road, Gurgaon 122103 (India)

    2016-10-01

    Inflammation of the eye is a usual clinical condition that can implicate any part of the eye. The nomenclature of variety of such inflammations is based on the ocular part involved. These diseases may jeopardize normal functioning of the eye on progression. In general, corticosteroids, antihistamines, mast cell stabilizers and non-steroidal anti-inflammatory drugs (NSAIDs) are used to treat inflammatory diseases/disorders of the eye. There have been several attempts via different approaches of drug delivery to overcome the low ocular bioavailability resulting from shorter ocular residence time. The features like safety, ease of elimination and ability to sustain drug release have led to application of biopolymers in ocular therapeutics. Numerous polymers of natural origin such as gelatin, collagen, chitosan, albumin, hyaluronic acid, alginates etc. have been successfully employed for preparation of different ocular dosage forms. Chitosan is the most explored biopolymer amongst natural biopolymers because of its inherent characteristics. The emergence of synthetic biopolymers (like PVP, PACA, PCL, POE, polyanhydrides, PLA, PGA and PLGA) has also added new dimensions to the drug delivery strategies meant for treatment of ophthalmic inflammations. The current review is an endeavor to describe the utility of a variety of biomaterials/polymers based drug delivery systems as carrier for anti-inflammatory drugs in ophthalmic therapeutics. - Highlights: • Numerous eye inflammations pose troubles in vision functions. • Low bioavailability by conventional drug delivery systems due to eye constraints • Drug carriers ensuring improved bioavailability to the eye are need of the hour. • Chitosan - most explored amongst all biomaterials for ocular delivery. • Emergence of novel synthetic carriers in ophthalmology.

  6. Mechanical strength of ceramic scaffolds reinforced with biopolymers is comparable to that of human bone

    DEFF Research Database (Denmark)

    Henriksen, S S; Ding, M; Vinther Juhl, M

    2011-01-01

    Eight groups of calcium-phosphate scaffolds for bone implantation were prepared of which seven were reinforced with biopolymers, poly lactic acid (PLA) or hyaluronic acid in different concentrations in order to increase the mechanical strength, without significantly impairing the microarchitecture....... Controls were un-reinforced calcium-phosphate scaffolds. Microarchitectural properties were quantified using micro-CT scanning. Mechanical properties were evaluated by destructive compression testing. Results showed that adding 10 or 15% PLA to the scaffold significantly increased the mechanical strength...

  7. Self-(Un)rolling Biopolymer Microstructures: Rings, Tubules, and Helical Tubules from the Same Material.

    Science.gov (United States)

    Ye, Chunhong; Nikolov, Svetoslav V; Calabrese, Rossella; Dindar, Amir; Alexeev, Alexander; Kippelen, Bernard; Kaplan, David L; Tsukruk, Vladimir V

    2015-07-13

    We have demonstrated the facile formation of reversible and fast self-rolling biopolymer microstructures from sandwiched active-passive, silk-on-silk materials. Both experimental and modeling results confirmed that the shape of individual sheets effectively controls biaxial stresses within these sheets, which can self-roll into distinct 3D structures including microscopic rings, tubules, and helical tubules. This is a unique example of tailoring self-rolled 3D geometries through shape design without changing the inner morphology of active bimorph biomaterials. In contrast to traditional organic-soluble synthetic materials, we utilized a biocompatible and biodegradable biopolymer that underwent a facile aqueous layer-by-layer (LbL) assembly process for the fabrication of 2D films. The resulting films can undergo reversible pH-triggered rolling/unrolling, with a variety of 3D structures forming from biopolymer structures that have identical morphology and composition. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Bioactivity of noble metal nanoparticles decorated with biopolymers and their application in drug delivery.

    Science.gov (United States)

    Rai, Mahendra; Ingle, Avinash P; Gupta, Indarchand; Brandelli, Adriano

    2015-12-30

    The unique properties of nanomaterials can be applied to solve different problems including new ways of drug delivery. Noble metal nanoparticles are most promising because they have been used for medicinal purposes since ancient time. It is evident from the past studies that the metallic nanoparticles are much more effective against various microorganisms when compared to their conventional counterparts. However, decoration of such nanoparticles with biomaterials add more advantages to their antimicrobial activity. Decoration of metal nanoparticles with biopolymers is a quite new area of research. Studies performed hitherto shown that nanoparticles of noble metals like silver, gold and platinum demonstrated better antibacterial, antifungal and antiviral activities when conjugated with biopolymers. The development of such technology has potential to develop materials that are more effective in the field of health science. Considering the importance and uniqueness of this concept, the present review aims to discuss the use of biopolymer-decorated metal nanoparticles for combating various diseases caused by microbial pathogens. Moreover, the nanotoxicity aspect has also been discussed. Copyright © 2015 Elsevier B.V. All rights reserved.

  9. Geophysical and Geotechnical Characterization of Beta-1,3/1,6-glucan Biopolymer treated Soil

    Science.gov (United States)

    Chang, I.; Cho, G.

    2012-12-01

    Bacteria or microbes in soil excrete hydrocarbon (e.g. polysaccharide) by-products which are called biopolymers. These biopolymers (or sometime biofilms) recently begun to make a mark on soil erosion control, aggregate stabilization, and drilling enhancement. However, the biological effect on soil behavior (e.g. bio-clogging or bio-cementation) has been poorly understood. In this study, the bio-cementation and bio-clogging effect induced by the existence of β-1,3/1,6-glucan biopolymers in soil were evaluated through a series of geophysical and geotechnical characterization tests in laboratory. According to the experimental test results, as the β-1,3/1,6-glucan content in soil increases, the compressive strength and shear wave velocity increase (i.e., bio-cementation) while the hydraulic conductivity decreases (i.e., bio-clogging) but the electrical conductivity increases due to the high electrical conductivity characteristic of β-1,3/1,6-glucan fibers. Coefficient of consolidation variation with the increases of β-1,3/1,6-glucan content in soil. SEM image of β-1,3/1,6-glucan treated soil. Fibers are form matices with soil particles.

  10. Applications of free-electron lasers to measurements of energy transfer in biopolymers and materials

    Science.gov (United States)

    Edwards, Glenn S.; Johnson, J. B.; Kozub, John A.; Tribble, Jerri A.; Wagner, Katrina

    1992-08-01

    Free-electron lasers (FELs) provide tunable, pulsed radiation in the infrared. Using the FEL as a pump beam, we are investigating the mechanisms for energy transfer between localized vibrational modes and between vibrational modes and lattice or phonon modes. Either a laser-Raman system or a Fourier transform infrared (FTIR) spectrometer will serve as the probe beam, with the attribute of placing the burden of detection on two conventional spectroscopic techniques that circumvent the limited response of infrared detectors. More specifically, the Raman effect inelastically shifts an exciting laser line, typically a visible frequency, by the energy of the vibrational mode; however, the shifted Raman lines also lie in the visible, allowing for detection with highly efficient visible detectors. With regards to FTIR spectroscopy, the multiplex advantage yields a distinct benefit for infrared detector response. Our group is investigating intramolecular and intermolecular energy transfer processes in both biopolymers and more traditional materials. For example, alkali halides contain a number of defect types that effectively transfer energy in an intermolecular process. Similarly, the functioning of biopolymers depends on efficient intramolecular energy transfer. Understanding these mechanisms will enhance our ability to modify biopolymers and materials with applications to biology, medecine, and materials science.

  11. The correlation between gelatin macroscale differences and nanoparticle properties: providing insight into biopolymer variability.

    Science.gov (United States)

    Stevenson, André T; Jankus, Danny J; Tarshis, Max A; Whittington, Abby R

    2018-05-21

    From therapeutic delivery to sustainable packaging, manipulation of biopolymers into nanostructures imparts biocompatibility to numerous materials with minimal environmental pollution during processing. While biopolymers are appealing natural based materials, the lack of nanoparticle (NP) physicochemical consistency has decreased their nanoscale translation into actual products. Insights regarding the macroscale and nanoscale property variation of gelatin, one of the most common biopolymers already utilized in its bulk form, are presented. Novel correlations between macroscale and nanoscale properties were made by characterizing similar gelatin rigidities obtained from different manufacturers. Samples with significant differences in clarity, indicating sample purity, obtained the largest deviations in NP diameter. Furthermore, a statistically significant positive correlation between macroscale molecular weight dispersity and NP diameter was determined. New theoretical calculations proposing the limited number of gelatin chains that can aggregate and subsequently get crosslinked for NP formation were presented as one possible reason to substantiate the correlation analysis. NP charge and crosslinking extent were also related to diameter. Lower gelatin sample molecular weight dispersities produced statistically smaller average diameters (<75 nm), and higher average electrostatic charges (∼30 mV) and crosslinking extents (∼95%), which were independent of gelatin rigidity, conclusions not shown in the literature. This study demonstrates that the molecular weight composition of the starting material is one significant factor affecting gelatin nanoscale properties and must be characterized prior to NP preparation. Identifying gelatin macroscale and nanoscale correlations offers a route toward greater physicochemical property control and reproducibility of new NP formulations for translation to industry.

  12. Using computer simulations to probe the structure and dynamics of biopolymers

    International Nuclear Information System (INIS)

    Levy, R.M.; Hirata, F.; Kim, K.; Zhang, P.

    1987-01-01

    The use of computer simulations to study internal motions and thermodynamic properties is receiving increased attention. One important use of the method is to provide a more fundamental understanding of the molecular information contained in various kinds of experiments on these complex systems. In the first part of this paper the authors review recent work in their laboratory concerned with the use of computer simulations for the interpretation of experimental probes of molecular structure and dynamics of proteins and nucleic acids. The interplay between computer simulations and three experimental techniques is emphasized: (1) nuclear magnetic resonance relaxation spectroscopy, (2) refinement of macro-molecular x-ray structures, and (3) vibrational spectroscopy. The treatment of solvent effects in biopolymer simulations is a difficult problem. It is not possible to study systematically the effect of solvent conditions, e.g. added salt concentration, on biopolymer properties by means of simulations alone. In the last part of the paper the authors review a more analytical approach they developed to study polyelectrolyte properties of solvated biopolymers. The results are compared with computer simulations

  13. The physicochemical properties of a spray dried glutinous rice starch biopolymer.

    Science.gov (United States)

    Laovachirasuwan, Pornpun; Peerapattana, Jomjai; Srijesdaruk, Voranuch; Chitropas, Padungkwan; Otsuka, Makoto

    2010-06-15

    Glutinous rice starch (GRS) is a biopolymer used widely in the food industry but not at all in the pharmaceutical industry. There are several ways to modify this biopolymer. Physical modification is simple and cheap because it requires no chemicals or biological agents. The aim of this study was to characterize the physicochemical properties of a spray dried glutinous rice starch (SGRS) produced from pregelatinized GRS. The surface morphology changed from an irregular to concave spherical shape as revealed by Scanning Electron Microscopy (SEM). SGRS was almost amorphous as determined by X-ray Diffraction (XRD) spectroscopy. The water molecules became linked through hydrogen bonds to the exposed hydroxyl group of amorphous SGRS as determined by Near Infrared (NIR) spectroscopy. Then, SGRS formed a colloid gel matrix with water and developed a highly viscous gelatinous form as determined using Differential Scanning Calorimetry (DSC) and a stress control type rheometer. In addition, SGRS can swell and produce a gelatinous surface barrier like a hydrophilic matrix biopolymer which controls drug release. Therefore, a novel application of SGRS is as a sustained release modifier for direct compression tablets in the pharmaceutical industry. Copyright 2010 Elsevier B.V. All rights reserved.

  14. Fabrication of porous biopolymer substrates for cell growth by UV laser: The role of pulse duration

    International Nuclear Information System (INIS)

    Castillejo, Marta; Rebollar, Esther; Oujja, Mohamed; Sanz, Mikel; Selimis, Alexandros; Sigletou, Maria; Psycharakis, Stelios; Ranella, Anthi; Fotakis, Costas

    2012-01-01

    Highlights: ► UV laser-induced superficial foaming in biopolymer films with fs, ps and ns pulses. ► Reduction of photochemical and structural modifications by ultrashort fs irradiation. ► Successful cell culture on laser-induced foam structure generated in chitosan. - Abstract: Ultraviolet laser irradiation using pulses with duration from the nanosecond to the femtosecond range was investigated aiming at the generation of a foam layer on films of the biopolymers chitosan, starch and their blend. We report on the morphological characteristics of the foams obtained upon irradiation and on the accompanying laser induced photochemistry, assessed by on line monitoring of the laser induced fluorescence. We identify the laser conditions (pulse duration) at which foaming is produced and discuss the obtained results in reference to the material properties, particularly extinction coefficient and thermal parameters. This article also reports on successful cell culture on the laser induced foam structure generated in chitosan, as an illustrative example of the possibility of broader use of laser induced biopolymer foaming structures in biology.

  15. Hydration water dynamics in biopolymers from NMR relaxation in the rotating frame.

    Science.gov (United States)

    Blicharska, Barbara; Peemoeller, Hartwig; Witek, Magdalena

    2010-12-01

    Assuming dipole-dipole interaction as the dominant relaxation mechanism of protons of water molecules adsorbed onto macromolecule (biopolymer) surfaces we have been able to model the dependences of relaxation rates on temperature and frequency. For adsorbed water molecules the correlation times are of the order of 10(-5)s, for which the dispersion region of spin-lattice relaxation rates in the rotating frame R(1)(ρ)=1/T(1)(ρ) appears over a range of easily accessible B(1) values. Measurements of T(1)(ρ) at constant temperature and different B(1) values then give the "dispersion profiles" for biopolymers. Fitting a theoretical relaxation model to these profiles allows for the estimation of correlation times. This way of obtaining the correlation time is easier and faster than approaches involving measurements of the temperature dependence of R(1)=1/T(1). The T(1)(ρ) dispersion approach, as a tool for molecular dynamics study, has been demonstrated for several hydrated biopolymer systems including crystalline cellulose, starch of different origins (potato, corn, oat, wheat), paper (modern, old) and lyophilized proteins (albumin, lysozyme). Copyright © 2010 Elsevier Inc. All rights reserved.

  16. Bioprocess Engineering Aspects of Biopolymer Production by the Cyanobacterium Spirulina Strain LEB 18

    Directory of Open Access Journals (Sweden)

    Roberta Guimarães Martins

    2014-01-01

    Full Text Available Microbial biopolymers can replace environmentally damaging plastics derived from petrochemicals. We investigated biopolymer synthesis by the cyanobacterium Spirulina strain LEB 18. Autotrophic culture used unmodified Zarrouk medium or modified Zarrouk medium in which the NaNO3 content was reduced to 0.25 g L−1 and the NaHCO3 content reduced to 8.4 g L−1 or increased to 25.2 g L−1. Heterotrophic culture used modified Zarrouk medium containing 0.25 g L−1 NaNO3 with the NaHCO3 replaced by 0.2 g L−1, 0.4 g L−1, or 0.6 g L−1 of glucose (C6H12O6 or sodium acetate (CH3COONa. Mixotrophic culture used modified Zarrouk medium containing 0.25 g L−1 NaNO3 plus 16.8 g L−1 NaHCO3 with the addition of 0.2 g L−1, 0.4 g L−1, or 0.6 g L−1 of glucose or sodium acetate. The highest biopolymer yield was 44% when LEB 18 was growing autotrophically in media containing 0.25 g L−1 NaNO3 and 8.4 g L−1 NaHCO3.

  17. Biological Effects of Spirulina (Arthrospira Biopolymers and Biomass in the Development of Nanostructured Scaffolds

    Directory of Open Access Journals (Sweden)

    Michele Greque de Morais

    2014-01-01

    Full Text Available Spirulina is produced from pure cultures of the photosynthetic prokaryotic cyanobacteria Arthrospira. For many years research centers throughout the world have studied its application in various scientific fields, especially in foods and medicine. The biomass produced from Spirulina cultivation contains a variety of biocompounds, including biopeptides, biopolymers, carbohydrates, essential fatty acids, minerals, oligoelements, and sterols. Some of these compounds are bioactive and have anti-inflammatory, antibacterial, antioxidant, and antifungal properties. These compounds can be used in tissue engineering, the interdisciplinary field that combines techniques from cell science, engineering, and materials science and which has grown in importance over the past few decades. Spirulina biomass can be used to produce polyhydroxyalkanoates (PHAs, biopolymers that can substitute synthetic polymers in the construction of engineered extracellular matrices (scaffolds for use in tissue cultures or bioactive molecule construction. This review describes the development of nanostructured scaffolds based on biopolymers extracted from microalgae and biomass from Spirulina production. These scaffolds have the potential to encourage cell growth while reducing the risk of organ or tissue rejection.

  18. Engineering bacterial biopolymers for the biosorption of heavy metals; new products and novel formulations

    International Nuclear Information System (INIS)

    Gutnick, D.L.; Bach, H.

    2000-01-01

    Bioremediation of heavy metal pollution remains a major challenge in environmental biotechnology. One of the approaches considered for application involves biosorption either to biomass or to isolated biopolymers. Many bacterial polysaccharides have been shown to bind heavy metals with varying degrees of specificity and affinity. While various approaches have been adopted to generate polysaccharide variants altered in both structure and activity, metal biosorption has not been examined. Polymer engineering has included structural modification through the introduction of heterologous genes of the biosynthetic pathway into specific mutants, leading either to alterations in polysaccharide backbone or side chains, or to sugar modification. In addition, novel formulations can be designed which enlarge the family of available bacterial biopolymers for metal-binding and subsequent recovery. An example discussed here is the use of amphipathic bioemulsifiers such as emulsan, produced by the oil-degrading Acinetobacter lwoffii RAG-1, that forms stable, concentrated (70%), oil-in-water emulsions (emulsanosols). In this system metal ions bind primarily at the oil/water interface, enabling their recovery and concentration from relatively dilute solutions. In addition to the genetic modifications described above, a new approach to the generation of amphipathic bioemulsifying formulations is based on the interaction of native or recombinant esterase and its derivatives with emulsan and other water-soluble biopolymers. Cation-binding emulsions are generated from a variety of hydrophobic substrates. The features of these and other systems will be discussed, together with a brief consideratiton of possible applications. (orig.)

  19. In-situ modification, regeneration, and application of keratin biopolymer for arsenic removal

    Energy Technology Data Exchange (ETDEWEB)

    Khosa, Muhammad A.; Ullah, Aman, E-mail: amanullah@ualberta.ca

    2014-08-15

    Graphical abstract: - Highlights: • In-situ chemical modification of keratin based material was carried out. • Characterization techniques such as SEM, FTIR, XRD, and DSC were employed. • TGA data was elaborated for its complete thermal and kinetic study. • Sorption of As(III) using modified material was experimentally studied. • Thermodynamics and Isotherm study was made for elucidation of adsorption data. - Abstract: Chemical modification of chicken feathers (CF) and their subsequent role in arsenic removal from water is presented in this paper. The ground CF were chemically treated with four selective dopants such as poly (ethylene glycol) (PEG) diglycidyl ether, poly (N-isopropylacrylamide) (PNIPAM), allyl alcohol (AA) and TrisilanolCyclohexyl POSS. After modification, the solubilized keratin was regenerated by precipitation at acidic pH. The structural changes and properties of modified biopolymer were compared with untreated CF and confirmed by different characterization techniques such as SEM, FTIR, XRD, and DSC. The TGA data was used to discuss thermal decomposition and kinetic behavior of modified biopolymer exhaustively. The modified biopolymers were further investigated as biosorbents for their application in As(III) removal from water. The AA and POSS supported biosorbents executed high removal capacity for As(III) up to 11.5 × 10{sup −2}and 11.0 × 10{sup −2} mg/g from 100 ml arsenic polluted water solution respectively. Thermodynamic parameters such as ΔG{sup 0}, ΔH{sup 0}, ΔS{sup 0} were also evaluated with the finding that overall sorption process was endothermic and spontaneous in nature. Based on linear and non-linear regression analysis, Freundlich Isotherm model showed good fit for obtained sorption data apart from high linear regression values supporting Langmuir isotherm model in sorption of As(III)

  20. Facile route of biopolymer mediated ferrocene (FO) nanoparticles in aqueous dispersion

    Energy Technology Data Exchange (ETDEWEB)

    Kaus, Noor Haida Mohd., E-mail: noorhaida@usm.my [School of Chemical Sciences, Universiti Sains Malaysia, 11800, Penang, Malaysia and Centre for Organized Matter Chemistry, School of Chemistry, Cantock' s Close, BS8 1TS, Bristol (United Kingdom); Collins, A. M.; Mann, S. [Centre for Organized Matter Chemistry, School of Chemistry, Cantock' s Close, BS8 1TS, Bristol (United Kingdom)

    2014-10-24

    In this paper, we present a facile method for production stable aqueous dispersion of ferrocene (FO) nanoparticles. Ferrocene compounds were employed to achieve stable nanodispersions, stabilized with three different biopolymers namely, alginate, CM-dextran and chitosan. The nanoparticles produce are spherical, less than 10 nm in mean diameter and highly stable without any sedimentation. Fourier infrared transform (FTIR) and X-ray diffraction (XRD) studies confirmed the purity of ferrocene nanoparticles there is no modifications occur during the preparation route. FTIR spectra results were consistent with the presence of absorption band of cyclopentadienyl ring (C{sub 5}H{sub 5}{sup −} ion) which assigned to ν(C-C) vibrations (1409 cm-1), δ(C-H) stretching at 1001 cm{sup −1} and π(C-H) vibrations at 812 cm{sup −1}. Furthermore, all functional group for biopolymers such as CO from carboxyl group of CM-dextran and sodium alginate appears at 1712 cm{sup −1} and 1709 cm{sup −1} respectively, indicating there are steric repulsion interactions for particles stabilization. Powder X-ray diffraction patterns of sedimented samples of the biopolymers-stabilized ferrocene (FO) showed all reflections which were indexed respectively to the (−110), (001), (−201), (−111), (200), (−211), (210), (120) and (111) according to the monoclinic phase ferrocene. This confirmed that the products obtained were of high purity of Fe and EDAX analysis also suggests that the presence of the Fe element in the colloidal dispersion.

  1. Neutron scattering studies of the dynamics of biopolymer-water systems using pulsed-source spectrometers

    Energy Technology Data Exchange (ETDEWEB)

    Middendorf, H.D. [Univ. of Oxford (United Kingdom); Miller, A. [Stirling Univ., Stirling (United Kingdom)

    1994-12-31

    Energy-resolving neutron scattering techniques provide spatiotemporal data suitable for testing and refining analytical models or computer simulations of a variety of dynamical processes in biomolecular systems. This paper reviews experimental work on hydrated biopolymers at ISIS, the UK Pulsed Neutron Facility. Following an outline of basic concepts and a summary of the new instrumental capabilities, the progress made is illustrated by results from recent experiments in two areas: quasi- elastic scattering from highly hydrated polysaccharide gels (agarose and hyaluronate), and inelastic scattering from vibrational modes of slightly hydrated collagen fibers.

  2. Single Molecule Science for Personalized Nanomedicine: Atomic Force Microscopy of Biopolymer-Protein Interactions

    Science.gov (United States)

    Hsueh, Carlin

    Nanotechnology has a unique and relatively untapped utility in the fields of medicine and dentistry at the level of single-biopolymer and -molecule diagnostics. In recent years atomic force microscopy (AFM) has garnered much interest due to its ability to obtain atomic-resolution of molecular structures and probe biophysical behaviors of biopolymers and proteins in a variety of biologically significant environments. The work presented in this thesis focuses on the nanoscale manipulation and observation of biopolymers to develop an innovative technology for personalized medicine while understanding complex biological systems. These studies described here primarily use AFM to observe biopolymer interactions with proteins and its surroundings with unprecedented resolution, providing a better understanding of these systems and interactions at the nanoscale. Transcriptional profiling, the measure of messenger RNA (mRNA) abundance in a single cell, is a powerful technique that detects "behavior" or "symptoms" at the tissue and cellular level. We have sought to develop an alternative approach, using our expertise in AFM and single molecule nanotechnology, to achieve a cost-effective high throughput method for sensitive detection and profiling of subtle changes in transcript abundance. The technique does not require amplification of the mRNA sample because the AFM provides three-dimensional views of molecules with unprecedented resolution, requires minimal sample preparation, and utilizes a simple tagging chemistry on cDNA molecules. AFM images showed collagen polymers in teeth and of Drebrin-A remodeling of filamentous actin structure and mechanics. AFM was used to image collagen on exposed dentine tubules and confirmed tubule occlusion with a desensitizing prophylaxis paste by Colgate-Palmolive. The AFM also superseded other microscopy tools in resolving F-actin helix remodeling and possible cooperative binding by a neuronal actin binding protein---Drebrin-A, an

  3. Biopolymer-based strategies in the design of smart medical devices and artificial organs.

    Science.gov (United States)

    Altomare, Lina; Bonetti, Lorenzo; Campiglio, Chiara E; De Nardo, Luigi; Draghi, Lorenza; Tana, Francesca; Farè, Silvia

    2018-06-01

    Advances in regenerative medicine and in modern biomedical therapies are fast evolving and set goals causing an upheaval in the field of materials science. This review discusses recent developments involving the use of biopolymers as smart materials, in terms of material properties and stimulus-responsive behavior, in the presence of environmental physico-chemical changes. An overview on the transformations that can be triggered in natural-based polymeric systems (sol-gel transition, polymer relaxation, cross-linking, and swelling) is presented, with specific focus on the benefits these materials can provide in biomedical applications.

  4. Eco-Friendly Extraction of Biopolymer Chitin and Carotenoids from Shrimp Waste

    Science.gov (United States)

    Prameela, K.; Venkatesh, K.; Divya vani, K.; Sudesh Kumar, E.; Mohan, CH Murali

    2017-08-01

    Astaxanthin a nutraceutical and chitin a natural biopolymer present in shrimp waste. In current chemical extraction methods HCl and NaOH are used for extraction and these chemicals are introduced into aquatic ecosystems are spoiling aquatic flora and fauna, pollute the environment and destroy astaxanthin. Lactobacillus species were isolated from gut of Solenocera melantho and characterized phenotypically and genotypically. Initial screening experiments have shown to be an effective and identified as Lactobacillus plantaram based on morphological, biochemical characteristics and molecular analysis. Efficiency of fermentation has shown with good yield of astaxanthin and recovery of chitin. Hence this alternative microbial process is having advantage than existing hazardous, non-economical chemical process.

  5. A differential vapor-pressure equipment for investigations of biopolymer interactions

    DEFF Research Database (Denmark)

    Andersen, Kim B; Koga, Y.; Westh, Peter

    2002-01-01

    the use of high-accuracy capacitance manometers and a leak-tight system of stainless steel pipes, below-scaled valves and metal-gasket fittings, DeltaP can be measured with a resolution of about 0.5 mubar (0.05 Pa) in some applications. This sensitivity level, along with other features of the equipment......, particularly a "gas-phase titration" routine for changing the cell composition, makes it effective for the investigations of several types of biopolymer interactions. These include isothermal studies of net affinities such as the adsorption of water to proteins or membranes, the preferential interaction...

  6. [Distribution and spatial ordering of biopolymer molecules in resting bacterial spores].

    Science.gov (United States)

    Duda, V I; Korolev, Iu N; El'-Registan, G I; Duzha, M V; Telegin, N L

    1978-01-01

    The presence, distribution and spatial arrangement of biopolymers in situ were studied in both a total intact spore and in a certain cellular layer using a spectroscopic technique of attenuated total refraction (ATR-IR) in the IR region. In contrast to vegetative cells, intact spores were characterized by isotropic distribution of protein components. This feature can be regarded as an index of the cryptobiotic state of spores. However, the distribution of protein components among individual layers of a spore was anisotropic. Bonds characterized by amide I and amide II bands were most often ordered in a layer which comprised cellular structures from the exosporium to the inner spore membrane.

  7. Neutron scattering studies of the dynamics of biopolymer-water systems using pulsed-source spectrometers

    International Nuclear Information System (INIS)

    Middendorf, H.D.; Miller, A.

    1994-01-01

    Energy-resolving neutron scattering techniques provide spatiotemporal data suitable for testing and refining analytical models or computer simulations of a variety of dynamical processes in biomolecular systems. This paper reviews experimental work on hydrated biopolymers at ISIS, the UK Pulsed Neutron Facility. Following an outline of basic concepts and a summary of the new instrumental capabilities, the progress made is illustrated by results from recent experiments in two areas: quasi- elastic scattering from highly hydrated polysaccharide gels (agarose and hyaluronate), and inelastic scattering from vibrational modes of slightly hydrated collagen fibers

  8. Adsorption of aluminum and lead from wastewater by chitosan-tannic acid modified biopolymers: Isotherms, kinetics, thermodynamics and process mechanism.

    Science.gov (United States)

    Badawi, M A; Negm, N A; Abou Kana, M T H; Hefni, H H; Abdel Moneem, M M

    2017-06-01

    Chitosan was reacted by tannic acid to obtain three modified chitosan biopolymer. Their chemical structures were characterized by FTIR and elemental analysis. The prepared biopolymers were used to adsorb Al(III) and Pb(II) metal ions from industrial wastewater. The factors affecting the adsorption process were biosorbent amount, initial concentration of metal ion and pH of the medium. The adsorption efficiency increased considerably with the increase of the biosorbent amount and pH of the medium. The adsorption process of biosorbent on different metal ions was fitted by Freundlich adsorption model. The adsorption kinetics was followed Pseudo-second-order kinetic model. The adsorption process occurred according to diffusion mechanism which was confirmed by the interparticle diffusion model. The modified biopolymers were efficient biosorbents for removal of Pb(II) and Al(III) metal ions from the medium. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. Biosurfactant-biopolymer driven microbial enhanced oil recovery (MEOR) and its optimization by an ANN-GA hybrid technique.

    Science.gov (United States)

    Dhanarajan, Gunaseelan; Rangarajan, Vivek; Bandi, Chandrakanth; Dixit, Abhivyakti; Das, Susmita; Ale, Kranthikiran; Sen, Ramkrishna

    2017-08-20

    A lipopeptide biosurfactant produced by marine Bacillus megaterium and a biopolymer produced by thermophilic Bacillus licheniformis were tested for their application potential in the enhanced oil recovery. The crude biosurfactant obtained after acid precipitation effectively reduced the surface tension of deionized water from 70.5 to 28.25mN/m and the interfacial tension between lube oil and water from 18.6 to 1.5mN/m at a concentration of 250mgL -1 . The biosurfactant exhibited a maximum emulsification activity (E 24 ) of 81.66% against lube oil. The lipopeptide micelles were stabilized by addition of Ca 2+ ions to the biosurfactant solution. The oil recovery efficiency of Ca 2+ conditioned lipopeptide solution from a sand-packed column was optimized by using artificial neural network (ANN) modelling coupled with genetic algorithm (GA) optimization. Three important parameters namely lipopeptide concentration, Ca 2+ concentration and solution pH were considered for optimization studies. In order to further improve the recovery efficiency, a water soluble biopolymer produced by Bacillus licheniformis was used as a flooding agent after biosurfactant incubation. Upon ANN-GA optimization, 45% tertiary oil recovery was achieved, when biopolymer at a concentration of 3gL -1 was used as a flooding agent. Oil recovery was only 29% at optimal conditions predicted by ANN-GA, when only water was used as flooding solution. The important characteristics of biopolymers such as its viscosity, pore plugging capabilities and bio-cementing ability have also been tested. Thus, as a result of biosurfactant incubation and biopolymer flooding under the optimal process conditions, a maximum oil recovery of 45% was achieved. Therefore, this study is novel, timely and interesting for it showed the combined influence of biosurfactant and biopolymer on solubilisation and mobilization of oil from the soil. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. A Vegetal Biopolymer-Based Biostimulant Promoted Root Growth in Melon While Triggering Brassinosteroids and Stress-Related Compounds

    Directory of Open Access Journals (Sweden)

    Luigi Lucini

    2018-04-01

    Full Text Available Plant biostimulants are receiving great interest for boosting root growth during the first phenological stages of vegetable crops. The present study aimed at elucidating the morphological, physiological, and metabolomic changes occurring in greenhouse melon treated with the biopolymer-based biostimulant Quik-link, containing lateral root promoting peptides, and lignosulphonates. The vegetal-based biopolymer was applied at five rates (0, 0.06, 0.12, 0.24, or 0.48 mL plant-1 as substrate drench. The application of biopolymer-based biostimulant at 0.12 and 0.24 mL plant-1 enhanced dry weight of melon leaves and total biomass by 30.5 and 27.7%, respectively, compared to biopolymer applications at 0.06 mL plant-1 and untreated plants. The root dry biomass, total root length, and surface in biostimulant-treated plants were significantly higher at 0.24 mL plant-1 and to a lesser extent at 0.12 and 0.48 mL plant-1, in comparison to 0.06 mL plant-1 and untreated melon plants. A convoluted biochemical response to the biostimulant treatment was highlighted through UHPLC/QTOF-MS metabolomics, in which brassinosteroids and their interaction with other hormones appeared to play a pivotal role. Root metabolic profile was more markedly altered than leaves, following application of the biopolymer-based biostimulant. Brassinosteroids triggered in roots could have been involved in changes of root development observed after biostimulant application. These hormones, once transported to shoots, could have caused an hormonal imbalance. Indeed, the involvement of abscisic acid, cytokinins, and gibberellin related compounds was observed in leaves following root application of the biopolymer-based biostimulant. Nonetheless, the treatment triggered an accumulation of several metabolites involved in defense mechanisms against biotic and abiotic stresses, such as flavonoids, carotenoids, and glucosinolates, thus potentially improving resistance toward plant stresses.

  11. Beyond Textbook Illustrations: Hand-Held Models of Ordered DNA and Protein Structures as 3D Supplements to Enhance Student Learning of Helical Biopolymers

    Science.gov (United States)

    Jittivadhna, Karnyupha; Ruenwongsa, Pintip; Panijpan, Bhinyo

    2010-01-01

    Textbook illustrations of 3D biopolymers on printed paper, regardless of how detailed and colorful, suffer from its two-dimensionality. For beginners, computer screen display of skeletal models of biopolymers and their animation usually does not provide the at-a-glance 3D perception and details, which can be done by good hand-held models. Here, we…

  12. Effect of γ-irradiation on the physical and mechanical properties of kefiran biopolymer film.

    Science.gov (United States)

    Shahabi-Ghahfarrokhi, Iman; Khodaiyan, Faramarz; Mousavi, Mohammad; Yousefi, Hossein

    2015-03-01

    In this study, the effect of different γ-ray dosages (3, 6, and 9 kGy) on the functional properties of kefiran biopolymer was investigated. The obtained results showed that increasing γ-ray dosage brought about an increase in the tensile strength of film specimens up to three-times. However, elongation at break, and tensile energy to break of γ-irradiated kefiran films decreased in the wake of increasing γ-ray dosage. γ-Irradiation could improve surface hydrophobicity, sensitivity of kefiran film specimens to water, and water vapor permeability, but yellowness of films increased, simultaneously. XRD spectrum confirmed increased crystallinity of γ-irradiated films. Melting point of films was constant but glass transition temperature decreased drastically at high γ-ray dosage (9 kGy). ATR-FTIR analysis confirmed that γ-ray engendered no changes in chemical functional groups. According to the result, a mechanism was proposed to percept the effects of γ-irradiation on kefiran biopolymer and its role on the functional properties of kefiran film. Hence, the functional properties of kefiran films were depend on the ratio of cross-linkages between polymer chains and produced mono and disaccharide by γ-irradiation. Copyright © 2014 Elsevier B.V. All rights reserved.

  13. Study of basic biopolymer as proton membrane for fuel cell systems

    International Nuclear Information System (INIS)

    Ramirez-Salgado, Joel

    2007-01-01

    Up to now, many research groups work to improve the electrical and mechanical properties of membranes with a low cost of production. The biopolymers could be an answer to produce proton membranes at low cost. This work demonstrates that the intrinsic membrane polymer and clays properties can help to develop a novel proton exchange membranes. Biopolymer composites (chitosan-oxide compounds) present conductivity between 10 -3 and 10 -2 S cm -1 . The measurements were calculated by EIS (1 MHz-0.05 Hz) using the two-electrode configuration. Different oxides were used: MgO, CaO, SiO 2 , Al 2 O 3 . The ionic conductivities were compared with Nafion (registered)'s in the same conditions of P and T. The catalyst layer/membrane ensemble was made during the design with the subsequent demonstration as membrane electrode assemblies and finally the fuel cell was built. Our focus was to increase the compatibility between the proton basic polymer exchange membrane and basic clays as CaO and test a new kind of fuel cell

  14. Rheological and mechanical properties of recycled polyethylene films contaminated by biopolymer.

    Science.gov (United States)

    Gere, D; Czigany, T

    2018-06-01

    Nowadays, with the increasing amount of biopolymers used, it can be expected that biodegradable polymers (e.g. PLA, PBAT) may appear in the petrol-based polymer waste stream. However, their impact on the recycling processes is not known yet; moreover, the properties of the products made from contaminated polymer blends are not easily predictable. Therefore, our goal was to investigate the rheological and mechanical properties of synthetic and biopolymer compounds. We made different compounds from regranulates of mixed polyethylene film waste and original polylactic acid (PLA) by extruison, and injection molded specimens from the compounds. We investigated the rheological properties of the regranulates, and the mechanical properties of the samples. When PLA was added, the viscosity and specific volume of all the blends decreased, and mechanical properties (tensile strength, modulus, and impact strength) changed significantly. Young's modulus increased, while elongation at break and impact strength decreased with the increase of the weight fraction of PLA. Copyright © 2018 Elsevier Ltd. All rights reserved.

  15. All Green Composites from Fully Renewable Biopolymers: Chitosan-Starch Reinforced with Keratin from Feathers

    Directory of Open Access Journals (Sweden)

    Cynthia G. Flores-Hernández

    2014-03-01

    Full Text Available The performance as reinforcement of a fibrillar protein such as feather keratin fiber over a biopolymeric matrix composed of polysaccharides was evaluated in this paper. Three different kinds of keratin reinforcement were used: short and long biofibers and rachis particles. These were added separately at 5, 10, 15 and 20 wt% to the chitosan-starch matrix and the composites were processed by a casting/solvent evaporation method. The morphological characteristics, mechanical and thermal properties of the matrix and composites were studied by scanning electron microscopy, thermogravimetric analysis, differential scanning calorimetry and dynamic mechanical analysis. The thermal results indicated that the addition of keratin enhanced the thermal stability of the composites compared to pure matrix. This was corroborated with dynamic mechanical analysis as the results revealed that the storage modulus of the composites increased with respect to the pure matrix. The morphology, evaluated by scanning electron microscopy, indicated a uniform dispersion of keratin in the chitosan-starch matrix as a result of good compatibility between these biopolymers, also corroborated by FTIR. These results demonstrate that chicken feathers can be useful to obtain novel keratin reinforcements and develop new green composites providing better properties, than the original biopolymer matrix.

  16. In situ enzyme aided adsorption of soluble xylan biopolymers onto cellulosic material.

    Science.gov (United States)

    Chimphango, Annie F A; Görgens, J F; van Zyl, W H

    2016-06-05

    The functional properties of cellulose fibers can be modified by adsorption of xylan biopolymers. The adsorption is improved when the degree of biopolymers substitution with arabinose and 4-O-methyl-glucuronic acid (MeGlcA) side groups, is reduced. α-l-Arabinofuranosidase (AbfB) and α-d-glucuronidase (AguA) enzymes were applied for side group removal, to increase adsorption of xylan from sugarcane (Saccharum officinarum L) bagasse (BH), bamboo (Bambusa balcooa) (BM), Pinus patula (PP) and Eucalyptus grandis (EH) onto cotton lint. The AguA treatment increased the adsorption of all xylans by up to 334%, whereas, the AbfB increased the adsorption of the BM and PP by 31% and 44%, respectively. A combination of AguA and AbfB treatment increased the adsorption, but to a lesser extent than achieved with AguA treatment. This indicated that the removal of the glucuronic acid side groups provided the most significant increase in xylan adsorption to cellulose, in particular through enzymatic treatment. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. Biopolymers codelivering engineered T cells and STING agonists can eliminate heterogeneous tumors.

    Science.gov (United States)

    Smith, Tyrel T; Moffett, Howell F; Stephan, Sirkka B; Opel, Cary F; Dumigan, Amy G; Jiang, Xiuyun; Pillarisetty, Venu G; Pillai, Smitha P S; Wittrup, K Dane; Stephan, Matthias T

    2017-06-01

    Therapies using T cells that are programmed to express chimeric antigen receptors (CAR T cells) consistently produce positive results in patients with hematologic malignancies. However, CAR T cell treatments are less effective in solid tumors for several reasons. First, lymphocytes do not efficiently target CAR T cells; second, solid tumors create an immunosuppressive microenvironment that inactivates T cell responses; and third, solid cancers are typified by phenotypic diversity and thus include cells that do not express proteins targeted by the engineered receptors, enabling the formation of escape variants that elude CAR T cell targeting. Here, we have tested implantable biopolymer devices that deliver CAR T cells directly to the surfaces of solid tumors, thereby exposing them to high concentrations of immune cells for a substantial time period. In immunocompetent orthotopic mouse models of pancreatic cancer and melanoma, we found that CAR T cells can migrate from biopolymer scaffolds and eradicate tumors more effectively than does systemic delivery of the same cells. We have also demonstrated that codelivery of stimulator of IFN genes (STING) agonists stimulates immune responses to eliminate tumor cells that are not recognized by the adoptively transferred lymphocytes. Thus, these devices may improve the effectiveness of CAR T cell therapy in solid tumors and help protect against the emergence of escape variants.

  18. Modulating structural hierarchies of manganese oxide in morphology and porosity by marine biopolymer for improved supercapacitors

    International Nuclear Information System (INIS)

    Zong, Lu; Wu, Xiaochen; You, Jun; Li, Mingjie; Li, Chaoxu

    2016-01-01

    Nanostructured MnO 2 is one of the most promising electrode materials for supercapacitors (SCs) on account of its exceptional properties including high theoretical capacitance, natural abundance, environmental safety and low cost. However its merits cannot be fully embodied by its current synthesis approaches, since most of them were normally tedious, costly, low yield or environment unfriendly, and poor in controlling multiple parameters of MnO 2 . Inspired by biopolymer-assisted synthesis of hierarchical inorganic materials in living systems, a marine biopolymer was used for structure-controllable synthesis of MnO 2 in this study. Functioning as the reductant, surfactant and directing agent, alginate could tune the hierarchical architecture of MnO 2 in multiple parameters including the dimension, nanometric size, crystallographic form and porosity, where δ-MnO 2 nanocrystals with the size of 5 ∼ 10 nm first assembled into nanosheets, and then flower-like structure with particle size tunable within 40 ∼ 200 nm as well as micro- and mesopores. Due to these unique hierarchies in both the morphology and porosity, as-prepared MnO 2 exhibited excellent performance as SC electrode, e.g. high power density (32.5 kW kg −1 ), high energy density (75.1 Wh kg −1 ) and great cycling stability. Given the green, low-temperature and scalable one-step process, this synthesis may pave a highly promising way to massive production of MnO 2 electrode materials for SCs.

  19. Biopolymer foams - Relationship between material characteristics and foaming behavior of cellulose based foams

    International Nuclear Information System (INIS)

    Rapp, F.; Schneider, A.; Elsner, P.

    2014-01-01

    Biopolymers are becoming increasingly important to both industry and consumers. With regard to waste management, CO 2 balance and the conservation of petrochemical resources, increasing efforts are being made to replace standard plastics with bio-based polymers. Nowadays biopolymers can be built for example of cellulose, lactic acid, starch, lignin or bio mass. The paper will present material properties of selected cellulose based polymers (cellulose propionate [CP], cellulose acetate butyrate [CAB]) and corresponding processing conditions for particle foams as well as characterization of produced parts. Special focus is given to the raw material properties by analyzing thermal behavior (differential scanning calorimetry), melt strength (Rheotens test) and molecular weight distribution (gel-permeation chromatography). These results will be correlated with the foaming behavior in a continuous extrusion process with physical blowing agents and underwater pelletizer. Process set-up regarding particle foam technology, including extrusion foaming and pre-foaming, will be shown. The characteristics of the resulting foam beads will be analyzed regarding part density, cell morphology and geometry. The molded parts will be tested on thermal conductivity as well as compression behavior (E-modulus, compression strength)

  20. 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.

  1. Development of Seaweed-based Biopolymers for Edible Films and Lectins

    Science.gov (United States)

    Praseptiangga, D.

    2017-04-01

    Marine macroalgae (seaweeds) as one of important groups of biopolymers play an important role in human life. Biopolymers have been studied regarding their film-forming properties to produce edible films intended as food packaging and active ingredient carriers. Edible film, a thin layer or which is an integral part of food and can be eaten together with, have been used to avoid food quality deterioration due to physico-chemical changes, texture changes, or chemical reactions. Film-forming materials can be utilized individually or as mixed composite blends. Proteins and polysaccharides used for their mechanical and structural properties, and hydrophobic substances (lipids, essential oils, and emulsifiers) to provide good moisture barrier properties. In addition, bioactive substances from marine natural products, including seaweeds, have been explored for being used in the fields of medicine, food science, pharmaceutical science, biochemistry, and glycobiology. Among them, lectins or carbohydrate-binding proteins from seaweeds have recently been remarked. Lectins (hemagglutinins) are widely distributed in nature and also good candidates in such prospecting of seaweeds. They are useful as convenient tools to discriminate differences in carbohydrate structures and reveal various biological activities through binding and interacting to carbohydrates, suggesting that they are promising candidates for medicinal and clinical application.

  2. Metrologically Traceable Determination of the Water Content in Biopolymers: INRiM Activity

    Science.gov (United States)

    Rolle, F.; Beltramino, G.; Fernicola, V.; Sega, M.; Verdoja, A.

    2017-03-01

    Water content in materials is a key factor affecting many chemical and physical properties. In polymers of biological origin, it influences their stability and mechanical properties as well as their biodegradability. The present work describes the activity carried out at INRiM on the determination of water content in samples of a commercial starch-derived biopolymer widely used in shopping bags (Mater-Bi^{circledR }). Its water content, together with temperature, is the most influencing parameter affecting its biodegradability, because of the considerable impact on the microbial activity which is responsible for the biopolymer degradation in the environment. The main scope of the work was the establishment of a metrologically traceable procedure for the determination of water content by using two electrochemical methods, namely coulometric Karl Fischer (cKF) titration and evolved water vapour (EWV) analysis. The obtained results are presented. The most significant operational parameters were considered, and a particular attention was devoted to the establishment of metrological traceability of the measurement results by using appropriate calibration procedures, calibrated standards and suitable certified reference materials. Sample homogeneity and oven-drying temperature were found to be the most important influence quantities in the whole water content measurement process. The results of the two methods were in agreement within the stated uncertainties. Further development is foreseen for the application of cKF and EWV to other polymers.

  3. Properties and characterization of bionanocomposite films prepared with various biopolymers and ZnO nanoparticles.

    Science.gov (United States)

    Kanmani, Paulraj; Rhim, Jong-Whan

    2014-06-15

    This study was aimed to develop biopolymer based antimicrobial films for active food packaging and to reduce environmental pollution caused by accumulation of synthetic packaging. The ZnO NPs were incorporated as antimicrobials into different biopolymers such as agar, carrageenan and CMC. Solvent casting method was performed to prepare active nanocomposite films. Methods such as FE-SEM, FT-IR and XRD were used to characterize resulting films. Physical, mechanical, thermal and antimicrobial properties were also examined. Remarkable surface morphological differences were observed between control and nanocomposite films. The crystallinity of ZnO was confirmed by XRD analysis. The addition of ZnO NPs increased color, UV barrier, moisture content, hydrophobicity, elongation and thermal stability of the films, while decreased WVP, tensile strength and elastic modulus. ZnO NPs impregnated films inhibited growth of L. monocytogenes and E. coli. So these newly prepared nanocomposite films can be used as active packaging film to extend shelf-life of food. Copyright © 2014 Elsevier Ltd. All rights reserved.

  4. Biopolymer production using fungus Mucor racemosus Fresenius and glycerol as substrate

    Directory of Open Access Journals (Sweden)

    Thaíssa Rodrigues Araújo

    Full Text Available Abstract This study evaluated extracellular production of biopolymer using fungus Mucor racemosus Fresenius and glycerol as a carbon source. Initially employing conical flasks of 500 mL containing 100 mL of cultive medium with 0.18 ± 0.03 g.L–1 of microorganisms, the results showed that the best conditions of the variables studied were: initial concentration of glycerol 50 g.L–1, fermentation time of 96 h, inoculum cultivation time of 120 h, and aeration in two stages–the first 24 hours without aeration and 72 hours fermentation with aeration of 2 vvm and 2 g.L–1 of yeast extract. The experiments conducted in a Biostat B fermenter with a 2.0 L capacity that contained 1.0 L of medium showed production of 16.35 g.L–1 gum formed and 75% glycerol consumption. These conditions produced a biopolymer with the molecular weight and total sugar content of 4.607×106 g.mol–1 (Da and 89.5%, respectively.

  5. Biopolymer foams - Relationship between material characteristics and foaming behavior of cellulose based foams

    Science.gov (United States)

    Rapp, F.; Schneider, A.; Elsner, P.

    2014-05-01

    Biopolymers are becoming increasingly important to both industry and consumers. With regard to waste management, CO2 balance and the conservation of petrochemical resources, increasing efforts are being made to replace standard plastics with bio-based polymers. Nowadays biopolymers can be built for example of cellulose, lactic acid, starch, lignin or bio mass. The paper will present material properties of selected cellulose based polymers (cellulose propionate [CP], cellulose acetate butyrate [CAB]) and corresponding processing conditions for particle foams as well as characterization of produced parts. Special focus is given to the raw material properties by analyzing thermal behavior (differential scanning calorimetry), melt strength (Rheotens test) and molecular weight distribution (gel-permeation chromatography). These results will be correlated with the foaming behavior in a continuous extrusion process with physical blowing agents and underwater pelletizer. Process set-up regarding particle foam technology, including extrusion foaming and pre-foaming, will be shown. The characteristics of the resulting foam beads will be analyzed regarding part density, cell morphology and geometry. The molded parts will be tested on thermal conductivity as well as compression behavior (E-modulus, compression strength).

  6. The stability and degradation kinetics of Sulforaphene in microcapsules based on several biopolymers via spray drying.

    Science.gov (United States)

    Tian, Guifang; Li, Yuan; Yuan, Qipeng; Cheng, Li; Kuang, Pengqun; Tang, Pingwah

    2015-05-20

    Sulforaphene (SFE) was extracted from the radish seeds and the purity of SFE extracted by our laboratory was 95%. It is well known that SFE can prevent cancers. It is also known that SFE is unstable to heat. To overcome the problem, SFE microcapsules using natural biopolymers were prepared by spray drying. The results indicated that SFE microcapsules using hydroxypropyl-β-cyclodextrin (HP-β-CD), maltodextrin (MD) and isolated soybean protein (SPI) as wall materials could effectively improve its stability against heat, especially SFE-loaded HP-β-CD and MD microcapsules. The amount of SFE in the microcapsules was found 20% higher than that of the non-encapsulated SFE under 90 °C in 168 h. Our finding suggested that the rate of degradation of the non-encapsulated and encapsulated SFE with HP-β-CD, MD and SPI followed the first-order kinetics. The speed of the degradation of the encapsulated SFE in biopolymers increased from SFE with HP-β-CD, to SFE with MD, and to SFE-SPI. The non-encapsulated SFE degrades fastest. Copyright © 2015 Elsevier Ltd. All rights reserved.

  7. Green synthesis of silver nanoparticles using biopolymers, carboxymethylated-curdlan and fucoidan

    International Nuclear Information System (INIS)

    Leung, Thomas Chun-Yiu; Wong, Chung Kai; Xie Yong

    2010-01-01

    There is a growing need in developing a reliable and eco-friendly methodology for the synthesis of metallic nanoparticles, which may be applied for many nanotechnological applications. Natural compounds such as biopolymers are one of the resources which could be used for this purpose. The present study involves the development of a simple, ecological and user-friendly method in synthesizing silver nanoparticles by using carboxymethylated-curdlan or fucoidan as reducing and stabilizing agents. Reduction of silver ions by these biopolymers occurred when heating at 100 deg. C, led to the formation of silver nanoparticles in the range of 40-80 nm in dimensions. The silver nanoparticles were formed readily within 10-15 min. Morphological observation and characterization of the silver nanoparticles were performed by using dynamic light scattering (DLS), high-resolution transmission electron microscopy (HRTEM), and UV-vis absorption spectrophotometer. The size of silver nanoparticles can be controlled by using different concentrations of carboxymethylated-curdlan, fucoidan or silver nitrate. This way of silver nanoparticles preparation is easy, fast, user-friendly and suitable for large-scale production.

  8. Comparison of KrF and ArF excimer laser treatment of biopolymer surface

    Energy Technology Data Exchange (ETDEWEB)

    Michaljaničová, I. [Department of Solid State Engineering, University of Chemistry and Technology, 166 28 Prague (Czech Republic); Slepička, P., E-mail: petr.slepicka@vscht.cz [Department of Solid State Engineering, University of Chemistry and Technology, 166 28 Prague (Czech Republic); Heitz, J.; Barb, R.A. [Institute of Applied Physics, Johannes Kepler University Linz, A-4040 Linz (Austria); Sajdl, P. [Department of Power Engineering, University of Chemistry and Technology, 166 28 Prague (Czech Republic); Švorčík, V. [Department of Solid State Engineering, University of Chemistry and Technology, 166 28 Prague (Czech Republic)

    2015-06-01

    Highlights: • The influence of ArF and KrF laser on biopolymer surface was determined. • ArF laser acts predominantly on biopolymer surface. • PHB roughness is increased similarly for both applied wavelengths. • Roughness of nanostructures can be precisely controlled. • ArF laser introduces nitrogen on PHB surface. - Abstract: The goal of this work was the investigation of the impact of two different excimer lasers on two biocompatible and biodegradable polymers (poly-L-lactide and poly hydroxybutyrate). Both polymers find usage in medical and pharmaceutical fields. The polymers were modified by KrF and ArF excimer lasers. Subsequently the impact on surface morphology, surface chemistry changes, and thermal properties was studied by means of confocal and AFM microscopy, FTIR and XPS spectroscopy and DSC calorimetry. Under the same conditions of laser treatment it was observed that ArF laser causes more significant changes on surface chemistry, surface morphology and pattern formation on the polymers under investigation. The data obtained in this work can be used for a wide range of possible applications, in tissue engineering or in combination with metallization in electronics, e.g. for biosensors.

  9. Surface changes of biopolymers PHB and PLLA induced by Ar+ plasma treatment and wet etching

    Science.gov (United States)

    Slepičková Kasálková, N.; Slepička, P.; Sajdl, P.; Švorčík, V.

    2014-08-01

    Polymers, especially group of biopolymers find potential application in a wide range of disciplines due to their biodegradability. In biomedical applications these materials can be used as a scaffold or matrix. In this work, the influence of the Ar+ plasma treatment and subsequent wet etching (acetone/water) on the surface properties of polymers were studied. Two biopolymers - polyhydroxybutyrate with 8% polyhydroxyvalerate (PHB) and poly-L-lactic acid (PLLA) were used in these experiments. Modified surface layers were analyzed by different methods. Surface wettability was characterized by determination of water contact angle. Changes in elemental composition of modified surfaces were performed by X-ray Photoelectron Spectroscopy (XPS). Surface morphology and roughness was examined using Atomic Force Microscopy (AFM). Gravimetry method was used to study the mass loss. It was found that the modification from both with plasma and wet etching leads to dramatic changes of surface properties (surface chemistry, morphology and roughness). Rate of changes of these features strongly depends on the modification parameters.

  10. Novel synthesis and characterization of a collagen-based biopolymer initiated by hydroxyapatite nanoparticles.

    Science.gov (United States)

    Bhuiyan, D; Jablonsky, M J; Kolesov, I; Middleton, J; Wick, T M; Tannenbaum, R

    2015-03-01

    In this study, we developed a novel synthesis method to create a complex collagen-based biopolymer that promises to possess the necessary material properties for a bone graft substitute. The synthesis was carried out in several steps. In the first step, a ring-opening polymerization reaction initiated by hydroxyapatite nanoparticles was used to polymerize d,l-lactide and glycolide monomers to form poly(lactide-co-glycolide) co-polymer. In the second step, the polymerization product was coupled with succinic anhydride, and subsequently was reacted with N-hydroxysuccinimide in the presence of dicyclohexylcarbodiimide as the cross-linking agent, in order to activate the co-polymer for collagen attachment. In the third and final step, the activated co-polymer was attached to calf skin collagen type I, in hydrochloric acid/phosphate buffer solution and the precipitated co-polymer with attached collagen was isolated. The synthesis was monitored by proton nuclear magnetic resonance, infrared and Raman spectroscopies, and the products after each step were characterized by thermal and mechanical analysis. Calculations of the relative amounts of the various components, coupled with initial dynamic mechanical analysis testing of the resulting biopolymer, afforded a preliminary assessment of the structure of the complex biomaterial formed by this novel polymerization process. Copyright © 2015. Published by Elsevier Ltd.

  11. Polymethacrylate-based monoliths as stationary phases for separation of biopolymers and immobilization of enzymes.

    Science.gov (United States)

    Martinović, Tamara; Josić, Djuro

    2017-11-01

    The experiences in the production and application of polymethacrylate-based monolithic supports, since their development almost thirty years ago, are presented. The main driving force for the development of new chromatographic supports was the necessity for the isolation and separation of physiologically active biopolymers and their use for therapeutic purposes. For this sake, a development of a method for fast separation, preventing denaturation and preserving their biological activity was necessary. Development of polysaccharide-based supports, followed by the introduction of polymer-based chromatographic media, is shortly described. This development was followed by the advances in monolithic media that are now used for both large- and small-scale separation of biopolymers and nanoparticles. Finally, a short overview is given about the applications of monoliths for sample displacement chromatography, resulting in isolation of physiologically active biomolecules, such as proteins, protein complexes, and nucleic acid, as well as high-throughput sample preparation for proteomic investigations. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Preformed amide-containing biopolymer for improving the environmental performance of synthesized urea–formaldehyde in agro-fiber composites

    Science.gov (United States)

    Altaf H. Basta; Houssni El-Saied; Jerrold E. Winandy; Ronald Sabo

    2011-01-01

    Investigations have continued for production high performance agro-based composites using environmentally acceptable approaches. This study examines the role of adding amide-containing biopolymers during synthesis of urea–formaldehyde (UF) on properties of adhesive produced, especially its adhesion potential. The environmental performance of UF-resin synthesized in the...

  13. Structural characterisation of aliphatic, non-hydrolyzable biopolymers in freshwater algae and a leaf cuticle by ruthenium tetroxide degradation

    NARCIS (Netherlands)

    Sinninghe Damsté, J.S.; Schouten, S.; Moerkerken, P.; Gelin, F.; Baas, M.; Leeuw, J.W. de

    1998-01-01

    Aliphatic, non-hydrolyzable biopolymers were subjected to RuO4-oxidation in order to examine the potential of this method in revealing details on their structures. The method was tested on model compounds first and found to cleave alkyl chains of aromatic moieties, double bonds and ether bonds.

  14. Chemical characterization of Xanthan biopolymers synthesized by Xanthomonas campestris pv pruni strains

    International Nuclear Information System (INIS)

    Moreira, Angelita da S.; Vendruscolo, Claire T.; Furlan, Ligia; Galland, Griselda

    2001-01-01

    In this work we describe the characterisation of Xanthan biopolymers synthesized by two Xanthomonas campestris pv pruni strains, in aerobic fermentation. By chromatography on TLC we could notice the presence of Mannose monomer in higher proportion in the 82 strain with relation to the another ones. The viscosity results showed the temperature dependence. The 06 and 82 strains had their viscosity increased whereas for the 87 strain we could observe a reduction with temperature increasing. The 13 C NMR spectrum of 87 strain showed the characteristic signals at approximately 92.8, 70.4 and 61.4 ppm, attributed to C1, C4 and C6 from glucose monomer, with higher intensity. (author)

  15. Study of the ionic conduction mechanism based on carboxymethyl cellulose biopolymer electrolytes

    Energy Technology Data Exchange (ETDEWEB)

    Samsudin, A. S.; Isa, M. I. N. [Universiti Malaysia Terengganu, Terengganu (Mali)

    2014-11-15

    Biodegradable carboxymethyl cellulose (CMC) doped with various compositions of NH{sub 4}Br biopolymer electrolytes (BE) were successfully prepared via a solution-cast technique. The ionic conductivity for the CMC-NH{sub 4}Br BE system was measured by using impedance spectroscopy, and the highest ambient temperature conductivity was observed to be 1.12 x 10{sup -4} S cm{sup -1} for the sample containing 25-wt.% NH{sub 4}Br. The temperature dependence of the ionic conductivity revealed that the BE system followed an Arrhenius behavior. Jonscher's universal power law was applied to analyze the AC conductivity of the highest conducting sample in the BE system, and the results indicate that the conduction is due to small polaron hopping (SPH) caused by a non-adiabatic mechanism.

  16. Effect of Some Biopolymers on the Rheological Behavior of Surimi Gel

    Directory of Open Access Journals (Sweden)

    Takahiro Noda

    2012-05-01

    Full Text Available The objective of this study was to investigate the effect of selected biopolymers on the rheological properties of surimi. In our paper, we highlight the functional properties and rheological aspects of some starch mixtures used in surimi. However, the influence of some other ingredients, such as cryoprotectants, mannans, and hydroxylpropylmethylcellulose (HPMC, on the rheological properties of surimi is also described. The outcome reveals that storage modulus increased with the addition of higher levels of starch. Moreover, the increasing starch level increased the breaking force, deformation, and gel strength of surimi as a result of the absorption of water by starch granules in the mixture to make the surimi more rigid. On the other hand, the addition of cryoprotectants, mannans, and HPMC improved the rheological properties of surimi. The data obtained in this paper could be beneficial particularly to the scientists who deal with food processing field.

  17. Investigation on the biomimetic influence of biopolymers on calcium phosphate precipitation-Part 1: Alginate

    International Nuclear Information System (INIS)

    Oliveira de Lima, Daniel; Gomes Aimoli, Cassiano; Beppu, Marisa Masumi

    2009-01-01

    The understanding of how macromocules act in precipitation of inorganic phases is the key knowledge that is needed to establish the foundation to mimic nature and produce materials with high mechanical modulus besides outstanding optical and thermal properties. This study investigated how addition of small amounts of alginate (7-70 ppm), that presents many carboxylic groups, affects phase distribution and morphology of calcium phosphates, obtained through precipitation and further submitted to calcination and sintering. The results lead to the conclusion that alginate action is dynamic, where alginate molecules act as templates to nucleation, and most of the biopolymer remains in solution even when all calcium phosphate has precipitated. However, despite the effect on phase composition being mainly related to the system's kinetics, alginate does present thermodynamic interaction with the precipitates. It is probable that it acts by reducing the free energy of nucleation, as in heterogeneous nucleation processes.

  18. Understanding release kinetics of biopolymer drug delivery microcapsules for biomedical applications

    International Nuclear Information System (INIS)

    Desai, Salil; Perkins, Jessica; Harrison, Benjamin S.; Sankar, Jag

    2010-01-01

    Drug delivery and dosage concentrations are considered as major focal points in conventional as well as battlefield emergency medicine. The concept of localizing drug delivery via microcapsules is an evolving field to confine the adverse side effects of high concentration drug doses. This paper focuses on understanding release kinetics through biopolymer microcapsules for time-dependent drug release. Calcium alginate microcapsules were manufactured using a direct-write inkjet technique. Rhodamine 6G was used as the release agent to observe the release kinetics from calcium alginate beads in distilled water. A design of experiments was constructed to compare the effect of the microcapsule diameter and different concentrations of calcium chloride (M) and sodium alginate (%, w/v) solutions on the release kinetics profiles of the microcapsules. This research gives insight to identify favorable sizes of microcapsules and concentrations of sodium alginate and calcium chloride solutions for controlled release behavior of drug delivery microcapsules.

  19. Effect of Nanopore Length on the Translocation Process of a Biopolymer: Numerical Study

    Directory of Open Access Journals (Sweden)

    Yong Kweon Suh

    2013-09-01

    Full Text Available In this study, we simulate the electrophoretic motion of a bio-polymer through a synthetic nanopore in the presence of an external bias voltage by considering the hydrodynamic interactions between the polymer and the fluid explicitly. The motion of the polymer is simulated by 3D Langevin dynamics technique by modeling the polymer as a worm-like-chain, while the hydrodynamic interactions are incorporated by the lattice Boltzmann equation. We report the simulation results for three different lengths of the nanopore. The translocation time increases with the pore length even though the electrophoretic force on the polymer is the same irrespective of the pore length. This is attributed to the fact that the translocation velocity of each bead inside the nanopore decreases with the pore length due to the increased fluid resistance force caused by the increase in the straightened portion of the polymer. We confirmed this using a theoretical formula.

  20. Biopolymer protected silver nanoparticles on the support of carbon nanotube as interface for electrocatalytic applications

    Energy Technology Data Exchange (ETDEWEB)

    Satyanarayana, M.; Kumar, V. Sunil; Gobi, K. Vengatajalabathy, E-mail: drkvgobi@gmail.com, E-mail: satyam.nitw@gmail.com [Department of Chemistry, National Institute of Technology, Warangal - 506004, Telangana (India)

    2016-04-13

    In this research, silver nanoparticles (SNPs) are prepared on the surface of carbon nanotubes via chitosan, a biopolymer linkage. Here chitosan act as stabilizing agent for nanoparticles and forms a network on the surface of carbon nanotubes. Synthesized silver nanoparticles-MWCNT hybrid composite is characterized by UV-Visible spectroscopy, XRD analysis, and FESEM with EDS to evaluate the structural and chemical properties of the nanocomposite. The electrocatalytic activity of the fabricated SNP-MWCNT hybrid modified glassy carbon electrode has been evaluated by cyclic voltammetry and electrochemical impedance analysis. The silver nanoparticles are of size ∼35 nm and are well distributed on the surface of carbon nanotubes with chitosan linkage. The prepared nanocomposite shows efficient electrocatalytic properties with high active surface area and excellent electron transfer behaviour.

  1. Effect of Graphene Nanoplatelets on the Physical and Antimicrobial Properties of Biopolymer-Based Nanocomposites

    Directory of Open Access Journals (Sweden)

    Roberto Scaffaro

    2016-05-01

    Full Text Available In this work, biopolymer-based nanocomposites with antimicrobial properties were prepared via melt-compounding. In particular, graphene nanoplatelets (GnPs as fillers and an antibiotic, i.e., ciprofloxacin (CFX, as biocide were incorporated in a commercial biodegradable polymer blend of poly(lactic acid (PLA and a copolyester (BioFlex®. The prepared materials were characterized by scanning electron microscopy (SEM, and rheological and mechanical measurements. Moreover, the effect of GnPs on the antimicrobial properties and release kinetics of CFX was evaluated. The results indicated that the incorporation of GnPs increased the stiffness of the biopolymeric matrix and allowed for the tuning of the release of CFX without hindering the antimicrobial activity of the obtained materials.

  2. Hindrances to precise recovery of cellular forces in fibrous biopolymer networks

    Science.gov (United States)

    Zhang, Yunsong; Feng, Jingchen; Heizler, Shay I.; Levine, Herbert

    2018-03-01

    How cells move through the three-dimensional extracellular matrix (ECM) is of increasing interest in attempts to understand important biological processes such as cancer metastasis. Just as in motion on flat surfaces, it is expected that experimental measurements of cell-generated forces will provide valuable information for uncovering the mechanisms of cell migration. However, the recovery of forces in fibrous biopolymer networks may suffer from large errors. Here, within the framework of lattice-based models, we explore possible issues in force recovery by solving the inverse problem: how can one determine the forces cells exert to their surroundings from the deformation of the ECM? Our results indicate that irregular cell traction patterns, the uncertainty of local fiber stiffness, the non-affine nature of ECM deformations and inadequate knowledge of network topology will all prevent the precise force determination. At the end, we discuss possible ways of overcoming these difficulties.

  3. Properties of films obtained from biopolymers of different origins for skin lesions therapy

    Directory of Open Access Journals (Sweden)

    Márcia Zilioli Bellini

    2015-04-01

    Full Text Available In this study, the effects of the origin of xanthan used, in combination with chitosan, to prepare films for the treatment of skin lesions were evaluated. The characteristics of the films obtained with xanthan commercially available for the food industry sector and xanthan originated from a fermentation process conducted in a pilot plant were compared. Results showed that the source did not strongly interfere in many of the properties of the films, such as the mechanical properties, cytotoxicity to L929 cells, absorption of simulated body fluid and culture medium, stability in water and saline solution. Hence, even though the properties of biopolymers of different sources might vary, the films prepared with two distinct types of xanthan gum could be considered as potentially safe and similar in terms of relevant characteristics considering the aimed application.

  4. Characterization of the mechanical properties of tough biopolymer fibres from the mussel byssus of Aulacomya ater.

    Science.gov (United States)

    Troncoso, O P; Torres, F G; Grande, C J

    2008-07-01

    Byssus fibres are tough biopolymer fibres produced by mussels to attach themselves to rocks. In this communication, we present the mechanical properties of the byssus from the South American mussel Aulacomya ater which have not been previously reported in the literature. The mechanical properties of the whole threads were assessed by uniaxial tensile tests of dry and hydrated specimens. Elastoplastic and elastomeric stress-strain curves were found for byssal threads from A. ater in the dry and hydrated state, respectively. The results obtained from mechanical tests were modelled using linear, power-law-type and Mooney-Rivlin relationships. These methods for dealing with tensile measurements of mussel byssus have the potential to be used with other stretchy biomaterials.

  5. Production of novel biopolymers in plants: recent technological advances and future prospects.

    Science.gov (United States)

    Snell, Kristi D; Singh, Vijay; Brumbley, Stevens M

    2015-04-01

    The production of novel biopolymers in plants has the potential to provide renewable sources of industrial materials through agriculture. In this review we will highlight recent progress with plant-based production of polyhydroxyalkanoates (PHAs), silk, elastin, collagen, and cyanophycin with an emphasis on the synthesis of poly[(R)-3-hydroxybutyrate] (PHB), a renewable biodegradable PHA polymer with potential commercial applications in plastics, chemicals, and feed markets. Improved production of PHB has required manipulation of promoters driving expression of transgenes, reduction in activity of endogenous enzymes in competing metabolic pathways, insertion of genes to increase carbon flow to polymer, and basic plant biochemistry to understand metabolic limitations. These experiments have increased our understanding of carbon availability and partitioning in different plant organelles, cell types, and organs, information that is useful for the production of other novel molecules in plants. Copyright © 2014 Elsevier Ltd. All rights reserved.

  6. Electron migration in hydrated biopolymers following pulsed irradiation at low temperatures

    International Nuclear Information System (INIS)

    Lith, D. van.

    1987-01-01

    Charge migration in biopolymer-water mixtures and the effect of water concentration on the charge migration is investigated by measuring the electrical conductivity and the light emission with the pulse radiolysis technique. A preliminary account of the microwave conductivity observed in hydrated DNA and collagen at low temperature after pulsed irradiation is given. The results show that when hydrated DNA or collagen are irradiated at low temperatures, conductivity transients with microsecond lifetime are observed. It is tentatively concluded that these transients are due to the highly mobile dry electron. The effect of water concentration on mobility, lifetime and migration distance of the electron is discussed. The effect of additives to the hydrated systems on the behaviour of the electron is described. It is shown that the observed effects of the additives confirm the earlier conclusions that the dry electron is the species responsible for the radiation induced conductivity. The water concentration in the DNA- and collagen-systems could be varied only between zero and approximately fifty percent, due to inhomogeneities which occur at higher water concentrations. Experiments on gelatin, a biopolymer which forms homogeneous samples with levels of hydration varying from almost zero to 100% water (ice) are described. Both the radiation induced and the dark microwave conductivity have been studied as a function of water content. Preliminary results of a study of the light emission from pulse irradiated DNA-water mixtures are reported in an attempt to establish a relation between the observed electron migration and the formation of excited states via charge neutralization. (Auth.)

  7. Effect of Different Purification Techniques on the Characteristics of Heteropolysaccharide-Protein Biopolymer from Durian (Durio zibethinus Seed

    Directory of Open Access Journals (Sweden)

    Hamed Mirhosseini

    2012-09-01

    Full Text Available Natural biopolymers from plant sources contain many impurities (e.g., fat, protein, fiber, natural pigment and endogenous enzymes, therefore, an efficient purification process is recommended to minimize these impurities and consequently improve the functional properties of the biopolymer. The main objective of the present study was to investigate the effect of different purification techniques on the yield, protein content, solubility, water- and oil-holding capacity of a heteropolysaccharide-protein biopolymer obtained from durian seed. Four different purification methods using different chemicals and solvents (i.e., A (isopropanol and ethanol, B (isopropanol and acetone, C (saturated barium hydroxide, and D (Fehling solution] to liberate the purified biopolymer from its crude form were compared. In most cases, the purification process significantly (p < 0.05 improved the physicochemical properties of heteropolysaccharide-protein biopolymer from durian fruit seed. The present work showed that the precipitation using isopropanol and acetone (Method B resulted in the highest purification yield among all the tested purification techniques. The precipitation using saturated barium hydroxide (Method C led to induce the highest solubility and relatively high capacity of water absorption. The current study reveals that the precipitation using Fehling solution (Method D most efficiently eliminates the protein fraction, thus providing more pure biopolymer suitable for biological applications.

  8. Valorization of industrial waste and by-product streams via fermentation for the production of chemicals and biopolymers.

    Science.gov (United States)

    Koutinas, Apostolis A; Vlysidis, Anestis; Pleissner, Daniel; Kopsahelis, Nikolaos; Lopez Garcia, Isabel; Kookos, Ioannis K; Papanikolaou, Seraphim; Kwan, Tsz Him; Lin, Carol Sze Ki

    2014-04-21

    The transition from a fossil fuel-based economy to a bio-based economy necessitates the exploitation of synergies, scientific innovations and breakthroughs, and step changes in the infrastructure of chemical industry. Sustainable production of chemicals and biopolymers should be dependent entirely on renewable carbon. White biotechnology could provide the necessary tools for the evolution of microbial bioconversion into a key unit operation in future biorefineries. Waste and by-product streams from existing industrial sectors (e.g., food industry, pulp and paper industry, biodiesel and bioethanol production) could be used as renewable resources for both biorefinery development and production of nutrient-complete fermentation feedstocks. This review focuses on the potential of utilizing waste and by-product streams from current industrial activities for the production of chemicals and biopolymers via microbial bioconversion. The first part of this review presents the current status and prospects on fermentative production of important platform chemicals (i.e., selected C2-C6 metabolic products and single cell oil) and biopolymers (i.e., polyhydroxyalkanoates and bacterial cellulose). In the second part, the qualitative and quantitative characteristics of waste and by-product streams from existing industrial sectors are presented. In the third part, the techno-economic aspects of bioconversion processes are critically reviewed. Four case studies showing the potential of case-specific waste and by-product streams for the production of succinic acid and polyhydroxyalkanoates are presented. It is evident that fermentative production of chemicals and biopolymers via refining of waste and by-product streams is a highly important research area with significant prospects for industrial applications.

  9. Integrated systems for biopolymers and bioenergy production from organic waste and by-products: a review of microbial processes.

    Science.gov (United States)

    Pagliano, Giorgia; Ventorino, Valeria; Panico, Antonio; Pepe, Olimpia

    2017-01-01

    Recently, issues concerning the sustainable and harmless disposal of organic solid waste have generated interest in microbial biotechnologies aimed at converting waste materials into bioenergy and biomaterials, thus contributing to a reduction in economic dependence on fossil fuels. To valorize biomass, waste materials derived from agriculture, food processing factories, and municipal organic waste can be used to produce biopolymers, such as biohydrogen and biogas, through different microbial processes. In fact, different bacterial strains can synthesize biopolymers to convert waste materials into valuable intracellular (e.g., polyhydroxyalkanoates) and extracellular (e.g., exopolysaccharides) bioproducts, which are useful for biochemical production. In particular, large numbers of bacteria, including Alcaligenes eutrophus , Alcaligenes latus , Azotobacter vinelandii , Azotobacter chroococcum , Azotobacter beijerincki , methylotrophs, Pseudomonas spp., Bacillus spp., Rhizobium spp., Nocardia spp., and recombinant Escherichia coli , have been successfully used to produce polyhydroxyalkanoates on an industrial scale from different types of organic by-products. Therefore, the development of high-performance microbial strains and the use of by-products and waste as substrates could reasonably make the production costs of biodegradable polymers comparable to those required by petrochemical-derived plastics and promote their use. Many studies have reported use of the same organic substrates as alternative energy sources to produce biogas and biohydrogen through anaerobic digestion as well as dark and photofermentation processes under anaerobic conditions. Therefore, concurrently obtaining bioenergy and biopolymers at a reasonable cost through an integrated system is becoming feasible using by-products and waste as organic carbon sources. An overview of the suitable substrates and microbial strains used in low-cost polyhydroxyalkanoates for biohydrogen and biogas

  10. Electrospun fibers of layered double hydroxide/biopolymer nanocomposites as effective drug delivery systems

    Energy Technology Data Exchange (ETDEWEB)

    Miao, Yue-E.; Zhu Hong; Chen Dan; Wang Ruiyu [State Key Laboratory of Molecular Engineering of Polymers, Department of Macromolecular Science, Fudan University, Shanghai 200433 (China); Tjiu, Weng Weei [Institute of Materials Research and Engineering, A-STAR (Agency for Science, Technology and Research), 3 Research Link, Singapore 117602 (Singapore); Liu Tianxi, E-mail: txliu@fudan.edu.cn [State Key Laboratory of Molecular Engineering of Polymers, Department of Macromolecular Science, Fudan University, Shanghai 200433 (China)

    2012-06-15

    Ibuprofen intercalated layered double hydroxide (LDH-IBU)/polycaprolactone (PCL) and LDH-IBU/polylactide (PLA) nanocomposite fibers are electrospun based on a combination of LDH-IBU with two kinds of biopolymers (i.e. PCL and PLA), to act as effective drug delivery systems. Ibuprofen (IBU) is chosen as a model drug, which is intercalated in MgAl-LDH by coprecipitation. Poly(oxyethylene-b-oxypropylene-b-oxyethylene) (Pluronic) is also added into PLA-based fibers as hydrophilicity enhancer and release modulator. LDH-IBU nanoparticles are uniformly dispersed throughout the nanocomposite fibers, as evidenced by transmission electron microscopy (TEM) observations. In vitro drug release studies show that initial IBU liberation from LDH-IBU/PCL composite fibers is remarkably slower than that from IBU/PCL fibers due to the sustained release property of LDH-IBU and heterogeneous nucleation effect of LDH-IBU on PCL chain segments. Surprisingly, the initial IBU release from LDH-IBU/PLA and LDH-IBU/PLA/Pluronic composite fibers is faster than that from the corresponding IBU/PLA and IBU/PLA/Pluronic fibers. This effect can be attributed to the strong interaction between alkyl groups in IBU molecules and methyl substituent groups of PLA as well as the hydrophilicity of LDH-IBU, which lead to an easier diffusion of water with a faster release of IBU from LDH-IBU/PLA and LDH-IBU/PLA/Pluronic composite fibers. - Graphical abstract: Ibuprofen intercalated layered double hydroxide (LDH-IBU)/polycaprolactone (PCL) and LDH-IBU/polylactide (PLA) nanocomposite fibers are electrospun based on the combination of LDHs with two kinds of biopolymers (i.e. PCL and PLA). LDH-IBU nanoparticles are uniformly dispersed throughout all the electrospun nanocomposite fibers even at a high loading level of 5 wt%. By combining the tunable drug release property of LDHs and electrospinning technique, the new drug delivery system is anticipated for effective loading and sustained release of drugs

  11. Design of polymer-biopolymer-hydroxyapatite biomaterials for bone tissue engineering: Through molecular control of interfaces

    Science.gov (United States)

    Verma, Devendra

    In this dissertation, novel biomaterials are designed for bone biomaterials and bone tissue engineering applications. Novel biomaterials of hydroxyapatite with synthetic and natural polymers have been fabricated using a combination of processing routes. Initially, we investigated hydroxyapatite-polycaprolactone-polyacrylic acid composites and observed that minimal interfacial interactions between polymer and mineral led to inadequate improvement in the mechanical properties. Bioactivity experiments on these composites showed that the presence of functional groups, such as carboxylate groups, influence bioactivity of the composites. We have developed and investigated composites of hydroxyapatite with chitosan and polygalacturonic acid (PgA). Chitosan and PgA are biocompatible, biodegradable, and also electrostatically complementary to each other. This strategy led to significant improvement in mechanical properties of new composites. The nanostructure analysis using atomic force microscopy revealed a multilevel organization in these composites. Enhancement in mechanical response was attributed to stronger interfaces due to strong electrostatic interaction between oppositely charged chitosan and PgA. Further analysis using the Rietveld method showed that biopolymers have marked impact on hydroxyapatite crystal growth and also on its crystal structure. Significant changes were observed in the lattice parameters of hydroxyapatite synthesized by following biomineralization method (organics mediated mineralization). For scaffold preparation, chitosan and PgA were mixed first, and then, nano-hydroxyapatite was added. Oppositely charged polyelectrolytes, such as chitosan and PgA, spontaneously form complex upon mixing. The poly-electrolyte complex exists as nano-sized particles. Chitosan/PgA scaffolds with and without hydroxyapatite were prepared by the freeze drying method. By controlling the rate of cooling and concentration, we have produced both fibrous and sheet

  12. Electrospun fibers of layered double hydroxide/biopolymer nanocomposites as effective drug delivery systems

    International Nuclear Information System (INIS)

    Miao, Yue-E.; Zhu Hong; Chen Dan; Wang Ruiyu; Tjiu, Weng Weei; Liu Tianxi

    2012-01-01

    Ibuprofen intercalated layered double hydroxide (LDH-IBU)/polycaprolactone (PCL) and LDH-IBU/polylactide (PLA) nanocomposite fibers are electrospun based on a combination of LDH-IBU with two kinds of biopolymers (i.e. PCL and PLA), to act as effective drug delivery systems. Ibuprofen (IBU) is chosen as a model drug, which is intercalated in MgAl-LDH by coprecipitation. Poly(oxyethylene-b-oxypropylene-b-oxyethylene) (Pluronic) is also added into PLA-based fibers as hydrophilicity enhancer and release modulator. LDH-IBU nanoparticles are uniformly dispersed throughout the nanocomposite fibers, as evidenced by transmission electron microscopy (TEM) observations. In vitro drug release studies show that initial IBU liberation from LDH-IBU/PCL composite fibers is remarkably slower than that from IBU/PCL fibers due to the sustained release property of LDH-IBU and heterogeneous nucleation effect of LDH-IBU on PCL chain segments. Surprisingly, the initial IBU release from LDH-IBU/PLA and LDH-IBU/PLA/Pluronic composite fibers is faster than that from the corresponding IBU/PLA and IBU/PLA/Pluronic fibers. This effect can be attributed to the strong interaction between alkyl groups in IBU molecules and methyl substituent groups of PLA as well as the hydrophilicity of LDH-IBU, which lead to an easier diffusion of water with a faster release of IBU from LDH-IBU/PLA and LDH-IBU/PLA/Pluronic composite fibers. - Graphical abstract: Ibuprofen intercalated layered double hydroxide (LDH-IBU)/polycaprolactone (PCL) and LDH-IBU/polylactide (PLA) nanocomposite fibers are electrospun based on the combination of LDHs with two kinds of biopolymers (i.e. PCL and PLA). LDH-IBU nanoparticles are uniformly dispersed throughout all the electrospun nanocomposite fibers even at a high loading level of 5 wt%. By combining the tunable drug release property of LDHs and electrospinning technique, the new drug delivery system is anticipated for effective loading and sustained release of drugs

  13. Synchrotron-Based Microspectroscopic Analysis of Molecular and Biopolymer Structures Using Multivariate Techniques and Advanced Multi-Components Modeling

    International Nuclear Information System (INIS)

    Yu, P.

    2008-01-01

    More recently, advanced synchrotron radiation-based bioanalytical technique (SRFTIRM) has been applied as a novel non-invasive analysis tool to study molecular, functional group and biopolymer chemistry, nutrient make-up and structural conformation in biomaterials. This novel synchrotron technique, taking advantage of bright synchrotron light (which is million times brighter than sunlight), is capable of exploring the biomaterials at molecular and cellular levels. However, with the synchrotron RFTIRM technique, a large number of molecular spectral data are usually collected. The objective of this article was to illustrate how to use two multivariate statistical techniques: (1) agglomerative hierarchical cluster analysis (AHCA) and (2) principal component analysis (PCA) and two advanced multicomponent modeling methods: (1) Gaussian and (2) Lorentzian multi-component peak modeling for molecular spectrum analysis of bio-tissues. The studies indicated that the two multivariate analyses (AHCA, PCA) are able to create molecular spectral corrections by including not just one intensity or frequency point of a molecular spectrum, but by utilizing the entire spectral information. Gaussian and Lorentzian modeling techniques are able to quantify spectral omponent peaks of molecular structure, functional group and biopolymer. By application of these four statistical methods of the multivariate techniques and Gaussian and Lorentzian modeling, inherent molecular structures, functional group and biopolymer onformation between and among biological samples can be quantified, discriminated and classified with great efficiency.

  14. The Effects of Biopolymer Encapsulation on Total Lipids and Cholesterol in Egg Yolk during in Vitro Human Digestion

    Directory of Open Access Journals (Sweden)

    Si-Kyung Lee

    2013-08-01

    Full Text Available The purpose of this study was to examine the effect of biopolymer encapsulation on the digestion of total lipids and cholesterol in egg yolk using an in vitro human digestion model. Egg yolks were encapsulated with 1% cellulose, pectin, or chitosan. The samples were then passed through an in vitro human digestion model that simulated the composition of mouth saliva, stomach acid, and the intestinal juice of the small intestine by using a dialysis tubing system. The change in digestion of total lipids was monitored by confocal fluorescence microscopy. The digestion rate of total lipids and cholesterol in all egg yolk samples dramatically increased after in vitro human digestion. The digestion rate of total lipids and cholesterol in egg yolks encapsulated with chitosan or pectin was reduced compared to the digestion rate of total lipids and cholesterol in other egg yolk samples. Egg yolks encapsulated with pectin or chitosan had lower free fatty acid content, and lipid oxidation values than samples without biopolymer encapsulation. Moreover, the lipase activity decreased, after in vitro digestion, in egg yolks encapsulated with biopolymers. These results improve our understanding of the effects of digestion on total lipids and cholesterol in egg yolk within the gastrointestinal tract.

  15. The Effects of Biopolymer Encapsulation on Total Lipids and Cholesterol in Egg Yolk during in Vitro Human Digestion

    Science.gov (United States)

    Hur, Sun-Jin; Kim, Young-Chan; Choi, Inwook; Lee, Si-Kyung

    2013-01-01

    The purpose of this study was to examine the effect of biopolymer encapsulation on the digestion of total lipids and cholesterol in egg yolk using an in vitro human digestion model. Egg yolks were encapsulated with 1% cellulose, pectin, or chitosan. The samples were then passed through an in vitro human digestion model that simulated the composition of mouth saliva, stomach acid, and the intestinal juice of the small intestine by using a dialysis tubing system. The change in digestion of total lipids was monitored by confocal fluorescence microscopy. The digestion rate of total lipids and cholesterol in all egg yolk samples dramatically increased after in vitro human digestion. The digestion rate of total lipids and cholesterol in egg yolks encapsulated with chitosan or pectin was reduced compared to the digestion rate of total lipids and cholesterol in other egg yolk samples. Egg yolks encapsulated with pectin or chitosan had lower free fatty acid content, and lipid oxidation values than samples without biopolymer encapsulation. Moreover, the lipase activity decreased, after in vitro digestion, in egg yolks encapsulated with biopolymers. These results improve our understanding of the effects of digestion on total lipids and cholesterol in egg yolk within the gastrointestinal tract. PMID:23965957

  16. Enhancement of Lignin Biopolymer Isolation from Hybrid Poplar by Organosolv Pretreatments

    Directory of Open Access Journals (Sweden)

    Miao Wu

    2014-01-01

    Full Text Available Lignocellulosic biomass is an abundant renewable resource that has the potential to displace petroleum in the production of biomaterials and biofuels. In the present study, the fractionation of different lignin biopolymers from hybrid poplar based on organosolv pretreatments using 80% aqueous methanol, ethanol, 1-propanol, and 1-butanol at 220°C for 30 min was investigated. The isolated lignin fractions were characterized by Fourier transform infrared spectroscopy (FT-IR, high-performance anion exchange chromatography (HPAEC, 2D nuclear magnetic resonance (2D NMR, and thermogravimetric analysis (TGA. The results showed that the lignin fraction obtained with aqueous ethanol (EOL possessed the highest yield and the strongest thermal stability compared with other lignin fractions. In addition, other lignin fractions were almost absent of neutral sugars (1.16–1.46% though lignin preparation extracted with 1-butanol (BOL was incongruent (7.53%. 2D HSQC spectra analysis revealed that the four lignin fractions mainly consisted of β-O-4′ linkages combined with small amounts of β-β′ and β-5′ linkages. Furthermore, substitution of Cα in β-O-4′ substructures had occurred due to the effects of dissolvent during the autocatalyzed alcohol organosolv pretreatments. Therefore, aqueous ethanol was found to be the most promising alcoholic organic solvent compared with other alcohols to be used in noncatalyzed processes for the pretreatment of lignocellulosic biomass in biorefinery.

  17. Single molecule force measurements delineate salt, pH and surface effects on biopolymer adhesion

    International Nuclear Information System (INIS)

    Pirzer, T; Geisler, M; Hugel, T; Scheibel, T

    2009-01-01

    In this paper we probe the influence of surface properties, pH and salt on the adhesion of recombinant spider silk proteins onto solid substrates with single molecule force spectroscopy. A single engineered spider silk protein (monomeric C 16 or dimeric (QAQ) 8 NR3) is covalently bound with one end to an AFM tip, which assures long-time measurements for hours with one and the same protein. The tip with the protein is brought into contact with various substrates at various buffer conditions and then retracted to desorb the protein. We observe a linear dependence of the adhesion force on the concentration of three selected salts (NaCl, NaH 2 PO 4 and NaI) and a Hofmeister series both for anions and cations. As expected, the more hydrophobic C 16 shows a higher adhesion force than (QAQ) 8 NR3, and the adhesion force rises with the hydrophobicity of the substrate. Unexpected is the magnitude of the dependences—we never observe a change of more than 30%, suggesting a surprisingly well-regulated balance between dispersive forces, water-structure-induced forces as well as co-solute-induced forces in biopolymer adhesion

  18. Biomimetic Nanofibrillation in Two-Component Biopolymer Blends with Structural Analogs to Spider Silk

    Science.gov (United States)

    Xie, Lan; Xu, Huan; Li, Liang-Bin; Hsiao, Benjamin S.; Zhong, Gan-Ji; Li, Zhong-Ming

    2016-10-01

    Despite the enormous potential in bioinspired fabrication of high-strength structure by mimicking the spinning process of spider silk, currently accessible routes (e.g., microfluidic and electrospinning approaches) still have substantial function gaps in providing precision control over the nanofibrillar superstructure, crystalline morphology or molecular orientation. Here the concept of biomimetic nanofibrillation, by copying the spiders’ spinning principles, was conceived to build silk-mimicking hierarchies in two-phase biodegradable blends, strategically involving the stepwise integration of elongational shear and high-pressure shear. Phase separation confined on nanoscale, together with deformation of discrete phases and pre-alignment of polymer chains, was triggered in the elongational shear, conferring the readiness for direct nanofibrillation in the latter shearing stage. The orderly aligned nanofibrils, featuring an ultralow diameter of around 100 nm and the “rigid-soft” system crosslinked by nanocrystal domains like silk protein dopes, were secreted by fine nanochannels. The incorporation of multiscale silk-mimicking structures afforded exceptional combination of strength, ductility and toughness for the nanofibrillar polymer composites. The proposed spider spinning-mimicking strategy, offering the biomimetic function integration unattainable with current approaches, may prompt materials scientists to pursue biopolymer mimics of silk with high performance yet light weight.

  19. Single molecule force measurements delineate salt, pH and surface effects on biopolymer adhesion

    Science.gov (United States)

    Pirzer, T.; Geisler, M.; Scheibel, T.; Hugel, T.

    2009-06-01

    In this paper we probe the influence of surface properties, pH and salt on the adhesion of recombinant spider silk proteins onto solid substrates with single molecule force spectroscopy. A single engineered spider silk protein (monomeric C16 or dimeric (QAQ)8NR3) is covalently bound with one end to an AFM tip, which assures long-time measurements for hours with one and the same protein. The tip with the protein is brought into contact with various substrates at various buffer conditions and then retracted to desorb the protein. We observe a linear dependence of the adhesion force on the concentration of three selected salts (NaCl, NaH2PO4 and NaI) and a Hofmeister series both for anions and cations. As expected, the more hydrophobic C16 shows a higher adhesion force than (QAQ)8NR3, and the adhesion force rises with the hydrophobicity of the substrate. Unexpected is the magnitude of the dependences—we never observe a change of more than 30%, suggesting a surprisingly well-regulated balance between dispersive forces, water-structure-induced forces as well as co-solute-induced forces in biopolymer adhesion.

  20. Silk fibroin/gold nanocrystals: a new example of biopolymer-based nanocomposites

    Science.gov (United States)

    Noinville, S.; Garnier, A.; Courty, A.

    2017-05-01

    The dispersion of nanoparticles in ordered polymer nanostructures can provide control over particle location and orientation, and pave the way for tailored nanomaterials that have enhanced mechanical, electrical, or optical properties. Here we used silk fibroin, a natural biopolymer, to embed gold nanocrystals (NCs), so as to obtain well-ordered structures such as nanowires and self-assembled triangular nanocomposites. Monodisperse gold NCs synthesized in organic media are mixed to silk fibroin and the obtained nanocomposites are characterized by UV-visible spectroscopy, transmission electron microscopy (TEM), scanning electron microscopy (FE-SEM), atomic force microscopy (AFM) and Infrared spectroscopy. The optical properties study of gold NCs and silk-gold nanocomposites shows that the Surface Plasmon band is blue shifted compared to gold NCs. The size and shape of NCs gold superlattices can be well controlled by the presence of silk fibroin giving nanowires and also self-assembled triangular nanocomposites as characterized by TEM, FE-SEM and AFM. The strong interaction between gold NCs and silk fibroin is also revealed by the conformation change of silk protein in presence of gold NCs, as shown by FTIR analysis. The formation of such ordered nanocomposites (gold NCs/silk fibroin) will provide new nanoplasmonic devices.

  1. An optically transparent, flexible, patterned and conductive silk biopolymer film (Conference Presentation)

    Science.gov (United States)

    Umar, Muhammad; Min, Kyungtaek; Kim, Sunghwan

    2017-02-01

    Transparent, flexible, and conducting films are of great interest for wearable electronics. For better biotic/abiotic interface, the films to integrate the electronics components requires the patterned surface conductors with optical transparency, smoothness, good electrical conductivity, along with the biofriendly traits of films. We focus on silk fibroin, a natural biopolymer extracted from the Bombyx mori cocoons, for this bioelectronics applications. Here we report an optically transparent, flexible, and patterned surface conductor on a silk film by burying a silver nanowires (AgNW) network below the surface of the silk film. The conducting silk film reveals high optical transparency of 80% and the excellent electronic conductivity of 15 Ω/sq, along with smooth surface. The integration of light emitting diode (LED) chip on the patterned electrodes confirms that the current can flow through the transparent and patterned electrodes on the silk film, and this result shows an application for integration of functional electronic/opto-electronic devices. Additionally, we fabricate a transparent and flexible radio frequency (RF) antenna and resistor on a silk film and apply these as a food sensor by monitoring the increasing resistance by the flow of gases from the spoiled food.

  2. Biopolymer-based hydrogels as injectable materials for tissue repair scaffolds

    International Nuclear Information System (INIS)

    Fiejdasz, Sylwia; Szczubiałka, Krzysztof; Lewandowska-Łańcucka, Joanna; Nowakowska, Maria; Osyczka, Anna M

    2013-01-01

    The progress in tissue regeneration is strongly dependent on the development of biocompatible materials with properties resembling those of a native tissue. Also, the application of noninvasive methods of delivering the scaffold into the tissue defect is of great importance. In this study we present a group of biopolymer-based materials as potential injectable scaffolds. In contrast to other studies involving collagen neutralization or additional incubation of gel in genipin solution, we propose collagen and collagen–chitosan gels crosslinked in situ with genipin. Since some parameters of the cells should be considered in the microscale, the steady-state fluorescence anisotropy was applied to study the microenvironment of the gels. To our knowledge we are the first to report on microrheological properties, such as gel time and microviscosity, for this group of hydrogels. Rapid gelation at physiological temperatures found makes these materials of special interest in applications requiring gel injectability. Physico-chemical investigation showed the influence of the crosslinking agent concentration and chitosan addition on the crosslinking degree, swelling ratio, gel microviscosity, and the degradation rate. Strong correlation was revealed between the surface wettability and the viability of cultured mesenchymal stem cells. Cytotoxicity studies indicated that the collagen–chitosan hydrogels showed the best biocompatibility. (paper)

  3. Dynamic light scattering of nano-gels of xanthan gum biopolymer in colloidal dispersion

    Directory of Open Access Journals (Sweden)

    Abbas Rahdar

    2016-09-01

    Full Text Available The dynamical properties of nanogels of xanthan gum (XG with hydrodynamic radius controlled in a size range from 5 nm to 35 nm, were studied at the different XG concentrations in water/sodium bis-2-ethylhexyl-sulfosuccinate (AOT/decane reverse micelles (RMs vs. mass fraction of nano-droplet (MFD at W = 40, using dynamic light scattering (DLS. The diffusion study of nanometer-sized droplets by DLS technique indicated that enhancing concentration of the XG polysaccharide resulted in exchanging the attractive interaction between nano-gels to repulsive interaction, as the mass fraction of nano-droplets increased. The reorientation time (τr of water nanodroplets decreased with MFD for water-in-oil AOT micro-emulsion comprising high concentration (0.0000625 of XG. On the other hand, decreasing concentration of biopolymer led to increasing the rotational correlation time of water nanodroplets with MFD. In conclusion, a single relaxation curve was observed for AOT inverse microemulsions containing different XG concentrations. Furthermore, the interaction between nanogels was changed from attractive to repulsive versus concentration of XG in the AOT RMs.

  4. The versatile biopolymer chitosan: potential sources, evaluation of extraction methods and applications.

    Science.gov (United States)

    Kaur, Surinder; Dhillon, Gurpreet Singh

    2014-05-01

    Among the biopolymers, chitin and its derivative chitosan (CTS) have been receiving increasing attention. Both are composed of randomly distributed β-(1-4)-linked d-glucosamine and N-acetyl glucosamine units. On commercial scale, CTS is mainly obtained from the crustacean shells. The chemical methods employed for extraction of CTS from crustacean shells are laden with many disadvantages. Waste fungal biomass represents a potential biological source of CTS, in fact with superior physico-chemical properties, such as high degree of deacetylation, low molecular weight, devoid of protein contamination and high bioactivity. Researchers around the globe are attempting to commercialize CTS production and extraction from fungal sources. Fungi are promising and environmentally benign source of CTS and they have the potential to completely replace crustacean-derived CTS. Waste fungal biomass resulting from various pharmaceutical and biotechnological industries is grown on inexpensive agro-industrial wastes and its by-products are a rich and inexpensive source of CTS. CTS is emerging as an important natural polymer having broad range of applications in different fields. In this context, the present review discusses the potential sources of CTS and their advantages and disadvantages. This review also deals with potential applications of CTS in different fields. Finally, the various attributes of CTS sought in different applications are discussed.

  5. Current Status and New Perspectives on Chitin and Chitosan as Functional Biopolymers.

    Science.gov (United States)

    Philibert, Tuyishime; Lee, Byong H; Fabien, Nsanzabera

    2017-04-01

    The natural biopolymer chitin and its deacetylated product chitosan are found abundantly in nature as structural building blocks and are used in all sectors of human activities like materials science, nutrition, health care, and energy. Far from being fully recognized, these polymers are able to open opportunities for completely novel applications due to their exceptional properties which an economic value is intrinsically entrapped. On a commercial scale, chitosan is mainly obtained from crustacean shells rather than from the fungal and insect sources. Significant efforts have been devoted to commercialize chitosan extracted from fungal and insect sources to completely replace crustacean-derived chitosan. However, the traditional chitin extraction processes are laden with many disadvantages. The present review discusses the potential bioextraction of chitosan from fungal, insect, and crustacean as well as its superior physico-chemical properties. The different aspects of fungal, insects, and crustacean chitosan extraction methods and various parameters having an effect on the yield of chitin and chitosan are discussed in detail. In addition, this review also deals with essential attributes of chitosan for high value-added applications in different fields and highlighted new perspectives on the production of chitin and deacetylated chitosan from different sources with the concomitant reduction of the environmental impact.

  6. Natural additives and agricultural wastes in biopolymer formulations for food packaging

    Science.gov (United States)

    Valdés, Arantzazu; Mellinas, Ana Cristina; Ramos, Marina; Garrigós, María Carmen; Jiménez, Alfonso

    2014-02-01

    The main directions in food packaging research are targeted towards improvements in food quality and food safety. For this purpose, food packaging providing longer product shelf-life, as well as the monitoring of safety and quality based upon international standards, is desirable. New active packaging strategies represent a key area of development in new multifunctional materials where the use of natural additives and/or agricultural wastes is getting increasing interest. The development of new materials, and particularly innovative biopolymer formulations, can help to address these requirements and also with other packaging functions such as: food protection and preservation, marketing and smart communication to consumers. The use of biocomposites for active food packaging is one of the most studied approaches in the last years on materials in contact with food. Applications of these innovative biocomposites could help to provide new food packaging materials with improved mechanical, barrier, antioxidant and antimicrobial properties. From the food industry standpoint, concerns such as the safety and risk associated with these new additives, migration properties and possible human ingestion and regulations need to be considered. The latest innovations in the use of these innovative formulations to obtain biocomposites are reported in this review. Legislative issues related to the use of natural additives and agricultural wastes in food packaging systems are also discussed.

  7. Conductivity and transport studies of plasticized chitosan-based proton conducting biopolymer electrolytes

    International Nuclear Information System (INIS)

    Shukur, M F; Yusof, Y M; Zawawi, S M M; Illias, H A; Kadir, M F Z

    2013-01-01

    This paper focuses on the conductivity and transport properties of chitosan-based solid biopolymer electrolytes containing ammonium thiocyanate (NH 4 SCN). The sample containing 40 wt% NH 4 SCN exhibited the highest conductivity value of (1.81 ± 0.50) × 10 −4  S cm −1 at room temperature. Conductivity has increased to (1.51 ± 0.12) × 10 −3  S cm −1 with the addition of 25 wt% glycerol. The temperature dependence of conductivity for both salted and plasticized systems obeyed the Arrhenius rule. The activation energy (E a ) was calculated for both systems and it is found that the sample with 40 wt% NH 4 SCN in the salted system obtained an E a value of 0.148 eV and that for the sample containing 25 wt% glycerol in the plasticized system is 0.139 eV. From the Fourier transform infrared studies, carboxamide and amine bands shifted to lower wavenumbers, indicating that chitosan has interacted with NH 4 SCN salt. Changes in the C–O stretching vibration band intensity are observed at 1067 cm −1 with the addition of glycerol. The Rice and Roth model was used to explain the transport properties of the salted and plasticized systems. (paper)

  8. Recovery of oil from oil-in-water emulsion using biopolymers by adsorptive method.

    Science.gov (United States)

    Elanchezhiyan, S Sd; Sivasurian, N; Meenakshi, Sankaran

    2014-09-01

    In the present study, it is aimed to identify, a low cost sorbent for the recovery of oil from oil-in-water emulsion using biopolymers such as chitin and chitosan. Chitin has the greater adsorption capacity than chitosan due to its hydrophobic nature. The characterizations of chitin and chitosan were done using FTIR, SEM, EDAX, XRD, TGA and DSC techniques. Under batch equilibrium mode, a systematic study was performed to optimize the various equilibrium parameters viz., contact time, pH, dosage, initial concentration of oil, and temperature. The adsorption process reached equilibrium at 40 min of contact time and the percentage removal of oil was found to be higher (90%) in the acidic medium. The Freundlich and Langmuir models were applied to describe the equilibrium isotherms and the isotherm constants were calculated. Thermodynamic parameters such as ΔG°, ΔH° and ΔS° were calculated to find out the nature of the sorption mechanism. The kinetic studies were investigated with reaction-based and diffusion-based models. The suitable mechanism for the removal of oil has been established. Copyright © 2014 Elsevier B.V. All rights reserved.

  9. Spinodal decomposition in a food colloid-biopolymer mixture: evidence for a linear regime

    Energy Technology Data Exchange (ETDEWEB)

    Bhat, Suresh [Department of Physics and Fribourg Center for Nanomaterials, University of Fribourg, 1700 Fribourg (Switzerland); Tuinier, Remco [Forschungszentrum Juelich, Institut fuer Festkoerperforschung, 52425 Juelich (Germany); Schurtenberger, Peter [Department of Physics and Fribourg Center for Nanomaterials, University of Fribourg, 1700 Fribourg (Switzerland)

    2006-07-05

    We investigate phase separation and structural evolution in a complex food colloid (casein micelles) and biopolymer (xanthan) mixture using small-angle light scattering. We demonstrate that phase separation is induced by a depletion mechanism, and that the resulting coexistence curve can be described by osmotic equilibrium theory for mixtures of colloids and polymer chains in a background solvent, taking into account interactions between the polymer chains in the excluded volume limit. We show that the light scattering pattern of an unstable mixture exhibits the typical behaviour of spinodal decomposition, and we are able to confirm the validity of dynamic similarity scaling. We find three distinct regimes (initial or linear, intermediate and transition stage) for the decomposition kinetics that differ in the time dependence of the peak position of the structure factor. In particular we find clear evidence for the existence of an initial linear regime, where the peak position remains constant and the amplitude grows. The existence of spinodal-like decomposition and the validity of universal scaling in the intermediate and transition stages have been found in previous studies of phase separation in attractive colloidal suspensions. However, to our knowledge the initial linear regime has never been observed in colloidal suspensions, and we attribute this at least partly to the effect of hydrodynamic interactions which are efficiently screened in our system due to the fact that the measurements were performed at high polymer concentrations, i.e. in the semi-dilute regime. (letter to the editor)

  10. Development of Biopolymer Composite Films Using a Microfluidization Technique for Carboxymethylcellulose and Apple Skin Particles

    Directory of Open Access Journals (Sweden)

    Inyoung Choi

    2017-06-01

    Full Text Available Biopolymer films based on apple skin powder (ASP and carboxymethylcellulose (CMC were developed with the addition of apple skin extract (ASE and tartaric acid (TA. ASP/CMC composite films were prepared by mixing CMC with ASP solution using a microfluidization technique to reduce particle size. Then, various concentrations of ASE and TA were incorporated into the film solution as an antioxidant and an antimicrobial agent, respectively. Fourier transform infrared (FTIR, optical, mechanical, water barrier, and solubility properties of the developed films were then evaluated to determine the effects of ASE and TA on physicochemical properties. The films were also analyzed for antioxidant effect on 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity and antimicrobial activities against Listeria monocytogenes, Staphylococcus aureus, Salmonella enterica, and Shigella flexneri. From the results, the ASP/CMC film containing ASE and TA was revealed to enhance the mechanical, water barrier, and solubility properties. Moreover, it showed the additional antioxidant and antimicrobial properties for application as an active packaging film.

  11. Biopolymer Doped with Titanium Dioxide Superhydrophobic Photocatalysis as Self-Clean Coating for Lightweight Composite

    Directory of Open Access Journals (Sweden)

    Anika Zafiah M. Rus

    2013-01-01

    Full Text Available The development of a lightweight composite (LC based on Portland cement concrete with waste lightweight aggregate (WLA additive was carried out to improve the sustainability and environmental impact and to offer potential cost savings without sacrificing strength. Treatment of the surface of the LC exposed to environmental attack by coating with biopolymer based on waste cooking oil doped with titanium dioxide photocatalysis (TOP with superhydrophilic property was found to affect the mechanical properties of the LC in a systematic way. The results of compressive strength showed that the composite achieved the minimum required strength for lightweight construction materials of 17.2 MPa. Scratch resistance measurements showed that the highest percentages loading of superhydrophilic particles (up to 2.5% of biomonomer weight for LC's surface coating gave the highest scratch resistance while the uncoated sample showed the least resistances. Scanning electron microscope (SEM pictures revealed the difference between the surface roughness for LC with and without TOP coating. TOP is also formulated to provide self-cleaning LC surfaces based on two principal ways: (1 the development by coating the LC with a photocatalytic superhydrophilic, (2 if such a superhydrophilic is illuminated by light, the grease, dirt, and organic contaminants will be decomposed and can easily be swept away by rain.

  12. Conductivity and transport studies of plasticized chitosan-based proton conducting biopolymer electrolytes

    Science.gov (United States)

    Shukur, M. F.; Yusof, Y. M.; Zawawi, S. M. M.; Illias, H. A.; Kadir, M. F. Z.

    2013-11-01

    This paper focuses on the conductivity and transport properties of chitosan-based solid biopolymer electrolytes containing ammonium thiocyanate (NH4SCN). The sample containing 40 wt% NH4SCN exhibited the highest conductivity value of (1.81 ± 0.50) × 10-4 S cm-1 at room temperature. Conductivity has increased to (1.51 ± 0.12) × 10-3 S cm-1 with the addition of 25 wt% glycerol. The temperature dependence of conductivity for both salted and plasticized systems obeyed the Arrhenius rule. The activation energy (Ea) was calculated for both systems and it is found that the sample with 40 wt% NH4SCN in the salted system obtained an Ea value of 0.148 eV and that for the sample containing 25 wt% glycerol in the plasticized system is 0.139 eV. From the Fourier transform infrared studies, carboxamide and amine bands shifted to lower wavenumbers, indicating that chitosan has interacted with NH4SCN salt. Changes in the C-O stretching vibration band intensity are observed at 1067 cm-1 with the addition of glycerol. The Rice and Roth model was used to explain the transport properties of the salted and plasticized systems.

  13. Tailored topography control of biopolymer surfaces by ultrafast lasers for cell–substrate studies

    International Nuclear Information System (INIS)

    Rusen, L.; Cazan, M.; Mustaciosu, C.; Filipescu, M.; Sandel, S.; Zamfirescu, M.; Dinca, V.; Dinescu, M.

    2014-01-01

    Nowadays, the culture surfaces used for in vitro testing must be capable of possessing an improved interface for cell interactions and adhesion. For this reason, the materials used need to have an appropriate chemistry and architecture of its surface, resembling to the extracellular matrix. Within this context, in this work we combined the advantages of natural biopolymer characteristics (chitosan) with the flexibility in surface texturing by ultrafast laser for creating functional microstructured surfaces for cell–substrate in vitro studies. A Ti:Sapphire femtosecond laser irradiation (λ = 775 nm and 387 nm) was used for tailoring surface morphological characteristics of chitosan based films (i.e. polymer “bubbles”, “fingertips” and “sponge-like” structures). These structures were investigated by scanning electron microscopy and atomic force microscopy. The morphology of the structures obtained was correlated with the response of oligodendrocytes cells line. In vitro tests on the patterned surface showed that early cell growth was conditioned by the microtopography and indicate possible uses of the structures in biomedical applications.

  14. Fractional Generalizations of Maxwell and Kelvin-Voigt Models for Biopolymer Characterization.

    Directory of Open Access Journals (Sweden)

    Bertrand Jóźwiak

    Full Text Available The paper proposes a fractional generalization of the Maxwell and Kelvin-Voigt rheological models for a description of dynamic behavior of biopolymer materials. It was found that the rheological models of Maxwell-type do not work in the case of modeling of viscoelastic solids, and the model which significantly better describes the nature of changes in rheological properties of such media is the modified fractional Kelvin-Voigt model with two built-in springpots (MFKVM2. The proposed model was used to describe the experimental data from the oscillatory and creep tests of 3% (w/v kuzu starch pastes, and to determine the values of their rheological parameters as a function of pasting time. These parameters provide a lot of additional information about structure and viscoelastic properties of the medium in comparison to the classical analysis of dynamic curves G' and G" and shear creep compliance J(t. It allowed for a comprehensive description of a wide range of properties of kuzu starch pastes, depending on the conditions of pasting process.

  15. Natural additives and agricultural wastes in biopolymer formulations for food packaging.

    Science.gov (United States)

    Valdés, Arantzazu; Mellinas, Ana Cristina; Ramos, Marina; Garrigós, María Carmen; Jiménez, Alfonso

    2014-01-01

    The main directions in food packaging research are targeted toward improvements in food quality and food safety. For this purpose, food packaging providing longer product shelf-life, as well as the monitoring of safety and quality based upon international standards, is desirable. New active packaging strategies represent a key area of development in new multifunctional materials where the use of natural additives and/or agricultural wastes is getting increasing interest. The development of new materials, and particularly innovative biopolymer formulations, can help to address these requirements and also with other packaging functions such as: food protection and preservation, marketing and smart communication to consumers. The use of biocomposites for active food packaging is one of the most studied approaches in the last years on materials in contact with food. Applications of these innovative biocomposites could help to provide new food packaging materials with improved mechanical, barrier, antioxidant, and antimicrobial properties. From the food industry standpoint, concerns such as the safety and risk associated with these new additives, migration properties and possible human ingestion and regulations need to be considered. The latest innovations in the use of these innovative formulations to obtain biocomposites are reported in this review. Legislative issues related to the use of natural additives and agricultural wastes in food packaging systems are also discussed.

  16. Effect of high-pressure food processing on the physical properties of synthetic and biopolymer films.

    Science.gov (United States)

    Galotto, M J; Ulloa, P A; Guarda, A; Gavara, R; Miltz, J

    2009-08-01

    The effect of high-pressure processing on 2 plastic food packaging films, a biopolymer (PLASiOx/PLA) and a synthetic polymer (PET-AlOx), was studied. Samples in direct contact with olive oil, as a fatty food simulant, and distilled water, as an aqueous simulant, were subjected to a pressure of 500MPa for 15 min at 50 degrees C. The mechanical, thermal, and gas barrier properties of both films were evaluated after the high-pressure processing (HPP) and compared to control samples that have not undergone this treatment. Significant changes in all properties were observed in both films after the HPP treatment and in contact with the food simulants. In both films an induced crystallization was noticed. In the PLASiOx/PLA film the changes were larger when in contact with water that probably acted as a plasticizer. In the PET-AlOx film the changes in properties were attributed to the formation of pinholes and cracks during the HPP treatment. In this film, most of the properties changed more in the presence of oil as the food simulant.

  17. Green synthesis of biopolymer-silver nanoparticle nanocomposite: an optical sensor for ammonia detection.

    Science.gov (United States)

    Pandey, Sadanand; Goswami, Gopal K; Nanda, Karuna K

    2012-11-01

    Biopolymer used for the production of nanoparticles (NPs) has attracted increasing attention. In the presence article we use aqueous solution of polysaccharide Cyamopsis tetragonaloba commonly known as guar gum (GG), from plants. GG acts as reductive preparation of silver nanoparticles which are found to be powder X-ray diffraction technique. Aqueous ammonia sensing study of polymer/silver nanoparticles nanocomposite (GG/AgNPs NC) was performed by optical method based on surface plasmon resonance (SPR). The performances of optical sensor were investigated which provide the excellent result. The response time of 2-3 s and the detection limit of ammonia solution, 1 ppm were found at room temperature. Thus, in future this room temperature optical ammonia sensor can be used for clinical and medical diagnosis for detecting low ammonia level in biological fluids, such as plasma, sweat, saliva, cerebrospinal liquid or biological samples in general for various biomedical applications in human. Copyright © 2012 Elsevier B.V. All rights reserved.

  18. Synthesis of nanohydrogels based on tragacanth gum biopolymer and investigation of swelling and drug delivery.

    Science.gov (United States)

    Sadat Hosseini, Masoomeh; Hemmati, Khadijeh; Ghaemy, Mousa

    2016-01-01

    The present article deals with preparation of pH responsive nanohydrogels based on tragacanth gum (TG) biopolymer for drug delivery. The nanohydrogels were prepared using different chemical reagents such as 3-aminopropyltriethoxysilane (APTES) modifier and glyceroldiglycidylether (GDE), polyvinyl alcohol (PVA), and glutaraldehyde (GA) as cross-linkers. The obtained nanohydrogels were characterized using different techniques such as scanning electron microscope (SEM), elemental analysis, FT-IR, zeta sizer and thermogravimetric analysis (TGA). The gel content increased with increasing the cross-linkers contents and reached to a maximum of 90%. The swelling behavior of nanohydrogels was investigated in terms of the effect of pH (2.2, 7.4 and 9), temperature (27, 37 and 60°C), and reaction time (2-24h). Loading of Indomethacin (IND) as a model drug showed dependence on the network structure of nanohydrogels. The total in vitro IND release showed dependence on the network structure of nanohydrogels and was in the range of 50-80% at pH 9 after 24h. Copyright © 2015 Elsevier B.V. All rights reserved.

  19. Natural additives and agricultural wastes in biopolymer formulations for food packaging

    Directory of Open Access Journals (Sweden)

    Arantzazu eValdés

    2014-02-01

    Full Text Available The main directions in food packaging research are targeted towards improvements in food quality and food safety. For this purpose, food packaging providing longer product shelf-life, as well as the monitoring of safety and quality based upon international standards, is desirable. New active packaging strategies represent a key area of development in new multifunctional materials where the use of natural additives and/or agricultural wastes is getting increasing interest. The development of new materials, and particularly innovative biopolymer formulations, can help to address these requirements and also with other packaging functions such as: food protection and preservation, marketing and smart communication to consumers. The use of biocomposites for active food packaging is one of the most studied approaches in the last years on materials in contact with food. Applications of these innovative biocomposites could help to provide new food packaging materials with improved mechanical, barrier, antioxidant and antimicrobial properties. From the food industry standpoint, concerns such as the safety and risk associated with these new additives, migration properties and possible human ingestion and regulations need to be considered. The latest innovations in the use of these innovative formulations to obtain biocomposites are reported in this review. Legislative issues related to the use of natural additives and agricultural wastes in food packaging systems are also discussed.

  20. Strategies for Automated Control of the Bioproduction of Mcl-PHA Biopolymers

    Directory of Open Access Journals (Sweden)

    P. Hrnčiřík

    2017-10-01

    Full Text Available Medium-chain-length polyhydroxyalkanoates (mcl-PHAs are polyesters synthesized by numerous bacteria as storage material. Despite being promising candidates for biodegradable materials of industrial interest and environmental value, their usage is still rather limited because of high production costs. One of the areas with considerable potential for further improvements is control of the production process. This paper deals with the experimental work related to the design of control strategies for mcl-PHA biopolymer production process (Pseudomonas putida KT2442 fed-batch cultivations. For this bioprocess, a set of five control strategies (two main and three auxiliary strategies have been proposed, together with the proper sequence of their switching during the fed-batch part of the production process. The application of these strategies with octanoic acid as a sole carbon source resulted in intracellular PHA content (max. mass fraction 65 % of mcl-PHA in cell dry mass (g g–1 and PHA productivity (max. 0.89 g L–1 h–1 comparable to the best results reported in the literature for this type of strain and carbon substrate.

  1. Complex electrical monitoring of biopolymer and iron mineral precipitation for microbial enhanced hydrocarbon recovery

    Science.gov (United States)

    Wu, Y.; Hubbard, C. G.; Dong, W.; Hubbard, S. S.

    2011-12-01

    Microbially enhanced hydrocarbon recovery (MEHR) mechanisms are expected to be impacted by processes and properties that occur over a wide range of scales, ranging from surface interactions and microbial metabolism at the submicron scale to changes in wettability and pore geometry at the pore scale to geological heterogeneities at the petroleum reservoir scale. To eventually ensure successful, production-scale implementation of laboratory-developed MEHR procedures under field conditions, it is necessary to develop approaches that can remotely monitor and accurately predict the complex microbially-facilitated transformations that are expected to occur during MEHR treatments in reservoirs (such as the evolution of redox profiles, oil viscosity or matrix porosity/permeability modifications). Our initial studies are focused on laboratory experiments to assess the geophysical signatures of MEHR-induced biogeochemical transformations, with an ultimate goal of using these approaches to monitor field treatments. Here, we explore the electrical signatures of two MEHR processes that are designed to produce end-products that will plug high permeability zones in reservoirs and thus enhance sweep efficiency. The MEHR experiments to induce biopolymers (in this case dextran) and iron mineral precipitates were conducted using flow-through columns. Leuconostoc mesenteroides, a facultative anaerobe, known to produce dextran from sucrose was used in the biopolymer experiments. Paused injection of sucrose, following inoculation and initial microbial attachment, was carried out on daily basis, allowing enough time for dextran production to occur based on batch experiment observations. Electrical data were collected on daily basis and fluid samples were extracted from the column for characterization. Changes in electrical signal were not observed during initial microbial inoculation. Increase of electrical resistivity and decrease of electrical phase response were observed during the

  2. Obtention of gelatin biopolymers by ionizing radiation; Obtencao de biopolimeros de gelatina por radiacao ionizante

    Energy Technology Data Exchange (ETDEWEB)

    Takinami, Patricia Yoko Inamura

    2014-07-01

    The gelatin (Gel) is a biocompatible and biodegradable biopolymer, which naturally forms semi-solid colloids or hydrogels in aqueous solutions. As a hydrophilic polymer, the Gel has structural and physico-mechanical properties that distinguish it from synthetic hydrophilic polymers. The study of these properties led to the development of the present work. Thus, Gel-based films and hydrogels were developed using ionizing radiation technology by different techniques: irradiation with {sup 60}Co, electron beam (EB) and/or pulsed EB. The Gel based-films enriched with different additives, such as glycerol (GLY), polyvinyl alcohol (PVA), butylated hydroxytoluene (BHT), acrylamide and/or vegetal fiber, were irradiated with doses from 10 to 60 kGy, depending on the additive; some parameters like mechanical properties, color, and water absorption were analyzed. In the radio-induced synthesis of GEL nanohydrogels, polyethylene glycol (PEG) and the mixture (MIX) of additives, PEG and GEL, the size, molar mass and surface morphology of the nanohydrogels were analyzed. There was a significant increase of gel fraction with increase of the radiation dose for the GEL/fiber samples. The GEL based-films with 10% PVA irradiated at 20 kGy showed the highest puncture strength. The addition of antioxidant BHT affected on some GEL based-films properties on applied conditions. Regarding the nanohydrogels, there was a decrease of hydrodynamic radius of MIX irradiated with {sup 60}Co from 68 ± 25 nm (2 kGy) to 35 ± 4 nm (5 kGy). The radiation proved to be a convenient tool in the modification of polymeric materials for both, GEL films and hydrogels. (author)

  3. An intelligent biopolymer gel with pendant L-proline methyl ester

    International Nuclear Information System (INIS)

    Yoshida, Masaru; Safranj, A.; Omichi, Hideki; Katakai, Ryoichi.

    1995-01-01

    Linear poly(acryloyl-L-proline methyl ester, A-ProOMe), obtained by radiation-induced polymerization of its monomer in ethanol, exhibits a lower critical solution temperature (LCST) at 14degC. A-ProOMe was copolymerized with a minor amount of 2-hydroxypropyl methacrylate (HPMA) or 2-hydroxyethyl methacrylate (HEMA), to obtain intelligent biopolymer gels for application in drug delivery systems. The poly(A-ProOMe/HPMA) gel was characterized by an initial rapid shrinkage at the surface in the swollen state, as resulting in formation of a rigid membrane barrier devoid of micropores. This gel is called a surface regulated matrix. In the case of poly(A-ProOMe/HEMA), no such a barrier formed, instead, the whole matrix shrunk without the disappearance of micropores. This gel is called a matrix pumping gel. Testosterone (T) was incorporated into the poly(A-ProOMe/HPMA) gel, and it was found that the daily dose of T released in vivo from this formulation remained constant at approximately 30 μg/day throughout an experimental period of 54 weeks. On the other hand, 9-β-D-arabinofuranosyladenine (Ara-A) was incorporated into the poly(A-ProOMe/HEMA) gel to evaluate the pulsatile drug release when cycled at 10 and 37degC. The in vitro release rate of Ara-A was found to be 11 ng/h at 10degC and 33 ng/h at 37degC. (author)

  4. Physical-biopolymer characterization of polyhydroxybutyrate-co-hydroxyvalerate (PHBV) blended with natural rubber latex

    Energy Technology Data Exchange (ETDEWEB)

    Kuntanoo, K., E-mail: thip-kk@hotmail.com [Graduate School of Khon Kaen University, Khon Kaen, 40002 Thailand (Thailand); Promkotra, S., E-mail: sarunya@kku.ac.th [Department of Geotechnology, Faculty of Technology, Khon Kaen University, Khon Kaen 40002 Thailand (Thailand); Kaewkannetra, P., E-mail: paknar@kku.ac.th [Department of Biotechnology, Faculty of Technology, Khon Kaen University, Khon Kaen 40002 Thailand (Thailand)

    2015-03-30

    A biopolymer of polyhydroxybutyrate-co-hydroxyvalerate (PHBV) is blended with bio-based materials, natural rubber latex, to improve their microstructures. The various ratios between PHBV and natural rubber latex are examined to develop their mechanical properties. In general, physical properties of PHBV are hard, brittle and low flexible while natural rubber (NR) is presented itself as high elastic materials. Concentrations of the PHBV solution are constituted at 1%, 2% and 3% (w/v). The mixtures of their PHBV solutions to natural rubber latex are produced the blended films in three different ratios of 4:6, 5:5 and 6:4, respectively. They are characterized by appearance analyses which are the scanning electron microscope (SEM), universal testing machine (UTM) and differential scanning calorimetry (DSC). The SEM photomicrographs of the blended films and the controlled PHBV can provide the void distribution in the range of 12-14% and 19-21%, respectively. For mechanical properties of the blended films, the various elastic moduli of 1%, 2% and 3% (w/v) PHBV are the average of 773, 956 and 1,007 kPa, respectively. The tensile strengths of the blends increase with the increased concentrations of PHBV, similarly trend to the elastic modulus. The crystallization and melting behavior of unmixed PHBV and the blends are determined by DSC. Melting transition temperatures (T{sub m}) of the unmixed PHBV are stated two melting peak at 154°C and 173°C. Besides, the melting peaks of the blends alter in the range of 152-156°C and 168-171°C, respectively. According to morphology of the blends, the void distribution decreases twice compared to the unmixed PHBV. The results of mechanical properties and thermal analysis indicate that the blended PHBV can be developed their properties by more resilient and wide range of temperature than usual.

  5. Structure and interactions in biomaterials based on membrane-biopolymer self-assembly

    Science.gov (United States)

    Koltover, Ilya

    Physical and chemical properties of artificial pure lipid membranes have been extensively studied during the last two decades and are relatively well understood. However, most real membrane systems of biological and biotechnological importance incorporate macromolecules either embedded into the membranes or absorbed onto their surfaces. We have investigated three classes of self-assembled membrane-biopolymer biomaterials: (i) Structure, interactions and stability of the two-dimensional crystals of the integral membrane protein bacteriorhodopsin (bR). We have conducted a synchrotron x-ray diffraction study of oriented bR multilayers. The important findings were as follows: (1) the protein 2D lattice exhibited diffraction patterns characteristic of a 2D solid with power-law decay of in-plane positional correlations, which allowed to measure the elastic constants of protein crystal; (2) The crystal melting temperature was a function of the multilayer hydration, reflecting the effect of inter-membrane repulsion on the stability of protein lattice; (3) Preparation of nearly perfect (mosaicity gene therapy applications. We have established that DNA complexes with cationic lipid (DOTAP) and a neutral lipid (DOPC) have a compact multilayer liquid crystalline structure ( L ca ) with DNA intercalated between the lipid bilayers in a periodic 2D smectic phase. Furthermore, a different 2D columnar phase of complexes was found in mixtures with a transfectionen-hancing lipid DOPE. This structure ( HcII ) derived from synchrotron x-ray diffraction consists of DNA coated by cationic lipid monolayers and arranged on a two-dimensional hexagonal lattice. Optical microscopy revealed that the L ca complexes bind stably to anionic vesicles (models of cellular membranes), whereas the more transfectant HcII complexes are unstable, rapidly fusing and releasing DNA upon adhering to anionic vesicles.

  6. Two kinds of ketoprofen enteric gel beads (CA and CS-SA using biopolymer alginate

    Directory of Open Access Journals (Sweden)

    Bingchao Cheng

    2018-03-01

    Full Text Available To obtain expected rapid-release and sustained-release of ketoprofen gel beads, this paper adopted biopolymer alginate to prepare alginate beads and chitosan-alginate gel beads. Formulation factors were investigated and optimized by the single factor test. The release of ketoprofen from calcium alginate gel beads in pH 1.0 hydrochloric acid solution was less than 10% during 2 h, then in pH6.8 was about 95% during 45 min, which met the requirements of rapid-release preparations. However, the drug release of chitosan-alginate gel beads in pH1.0 was less than 5% during 2 h, then in pH6.8 was about 50% during 6 h and reached more than 95% during 12 h, which had a good sustained-release behavior. In addition, the release kinetics of keteprofen from the calcium alginate gel beads fitted well with the Korsmeyer–Peppas model and followed a case-II transport mechanism. However, the release of keteprofen from the chitosan-alginate gel beads exhibited a non-Fickian mechanism and based on the mixed mechanisms of diffusion and polymer relaxation from chitosan-alginate beads. In a word, alginate gel beads of ketoprofen were instant analgesic, while chitosan-alginate gel beads could control the release of ketoprofen during gastro-intestinal tract and prolong the drug's action time. Keywords: Gel beads, Enteric rapid-release, Enteric sustained-release, Ketoprofen

  7. Highly Stable, Functional Hairy Nanoparticles and Biopolymers from Wood Fibers: Towards Sustainable Nanotechnology.

    Science.gov (United States)

    Sheikhi, Amir; Yang, Han; Alam, Md Nur; van de Ven, Theo G M

    2016-07-20

    Nanoparticles, as one of the key materials in nanotechnology and nanomedicine, have gained significant importance during the past decade. While metal-based nanoparticles are associated with synthetic and environmental hassles, cellulose introduces a green, sustainable alternative for nanoparticle synthesis. Here, we present the chemical synthesis and separation procedures to produce new classes of hairy nanoparticles (bearing both amorphous and crystalline regions) and biopolymers based on wood fibers. Through periodate oxidation of soft wood pulp, the glucose ring of cellulose is opened at the C2-C3 bond to form 2,3-dialdehyde groups. Further heating of the partially oxidized fibers (e.g., T = 80 °C) results in three products, namely fibrous oxidized cellulose, sterically stabilized nanocrystalline cellulose (SNCC), and dissolved dialdehyde modified cellulose (DAMC), which are well separated by intermittent centrifugation and co-solvent addition. The partially oxidized fibers (without heating) were used as a highly reactive intermediate to react with chlorite for converting almost all aldehyde to carboxyl groups. Co-solvent precipitation and centrifugation resulted in electrosterically stabilized nanocrystalline cellulose (ENCC) and dicarboxylated cellulose (DCC). The aldehyde content of SNCC and consequently surface charge of ENCC (carboxyl content) were precisely controlled by controlling the periodate oxidation reaction time, resulting in highly stable nanoparticles bearing more than 7 mmol functional groups per gram of nanoparticles (e.g., as compared to conventional NCC bearing AFM), transmission electron microscopy (TEM), and scanning electron microscopy (SEM) attested to the rod-like morphology. Conductometric titration, Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance (NMR), dynamic light scattering (DLS), electrokinetic-sonic-amplitude (ESA) and acoustic attenuation spectroscopy shed light on the superior properties of these

  8. The battle for the "green" polymer. Different approaches for biopolymer synthesis: bioadvantaged vs. bioreplacement.

    Science.gov (United States)

    Hernández, Nacú; Williams, R Christopher; Cochran, Eric W

    2014-05-14

    Biopolymers have been used throughout history; however, in the last two centuries they have seen a decrease in their utilization as the proliferation of inexpensive and mass-produced materials from petrochemical feedstocks quickly became better-suited to meeting society's needs. In recent years, high petroleum prices and the concern of society to adopt greener and cleaner products has led to an increased interest in biorenewable polymers and the use of sustainable technologies to produce them. Industrial and academic researchers alike have targeted several routes for producing these renewable materials. In this perspective, we compare and contrast two distinct approaches to the economical realization of these materials. One mentality that has emerged we term "bioreplacement", in which the fields of synthetic biology and catalysis collaborate to coax petrochemical monomers from sugars and lignocellulosic feedstocks that can subsequently be used in precisely the same ways to produce precisely the same polymers as we know today. For example, the metabolic engineering of bacteria is currently being explored as a viable route to common monomers such as butadiene, isoprene, styrene, acrylic acid, and sebacic acid, amongst others. Another motif that has recently gained traction may be referred to as the "bioadvantage" strategy, where the multifunctional "monomers" given to us by nature are combined in novel ways using novel chemistries to yield new polymers with new properties; for these materials to compete with their petroleum-based counterparts, they must add some advantage, for example less cost. For instance, acrylated epoxidized soybean oil readily undergoes polymerization to thermosets and recently, thermoplastic rubbers. Additionally, many plants produce pre-polymeric or polymeric materials that require little or no post modification to extract and make use of these compounds.

  9. FORMULATION AND TECHNOLOGY DEVELOPMENT OF HERBAL PHENOLIC BIOPOLYMER-CONTAINING FILMS FOR BURN TREATMENT.

    Science.gov (United States)

    Gokadze, S; Barbakadze, V; Mulkijanyan, K; Bakuridze, A; Bakuridze, L

    2017-06-01

    Application of phytofilms based on biosolublepolymers is considered as a prospectivemethod for burn treatment . Herbal remedies contain biologically active substances, that are relatively less toxic, do not cause skin irritation or allergic reactions and, importantly, affectstrains of the microorganisms and viruses resistant to antibiotics and synthetic drugs. Nowadays, the advantages are given to such burn healing drugs, which along with high specific efficacy, have analgesic, anti-inflammatory and antimicrobial effects, and don't irritate the tissues. The mentioned peculiarities are characteristic for a new herbal phenolic biopolymer poly[3-(3,4-dihydroxyphenyl) glyceric acid](PDGA), isolated from the roots and stems of different comfrey species . The aim of the study was the development of the formulation and technology of biosoluble films for burn treatment on the basis of PDGA. The optimal content of phytofilm for burn healing was selected on the basis of the biopharmaceutical study results. The impact of the film-former on the quality, adhesion and moisture absorption of the phytofilmhas been studied. The optimal degree of the phytofilm moisture, determining its high adhesive properties,was established. The film prepared on the basis of sodium alginate, with 30.4% humidity, demonstrated the greatest adhesion strength. After investigation of the PDGA release it was found, that the hydrophilic bases such as: sodium carboxymethyl-cellulose (69.2%) andsodium alginate (78,65%) appeared to be optimal among the others. At the same time, taking into consideration the disadvantages of sodium carboxymethyl-cellulose (tautening effect on burnt surface, relatively low stability), a film based on sodium alginate has been chosen. The manufacturing technology for obtaining PDGA-containing phytofilm by casting is proposed. Theshelf-lifeofproposedPDGA-containingphytofilmis 2 years.

  10. Chemical composition and molecular structure of polysaccharide-protein biopolymer from Durio zibethinus seed: extraction and purification process

    Directory of Open Access Journals (Sweden)

    Amid Bahareh

    2012-10-01

    Full Text Available Abstract Background The biological functions of natural biopolymers from plant sources depend on their chemical composition and molecular structure. In addition, the extraction and further processing conditions significantly influence the chemical and molecular structure of the plant biopolymer. The main objective of the present study was to characterize the chemical and molecular structure of a natural biopolymer from Durio zibethinus seed. A size-exclusion chromatography coupled to multi angle laser light-scattering (SEC-MALS was applied to analyze the molecular weight (Mw, number average molecular weight (Mn, and polydispersity index (Mw/Mn. Results The most abundant monosaccharide in the carbohydrate composition of durian seed gum were galactose (48.6-59.9%, glucose (37.1-45.1%, arabinose (0.58-3.41%, and xylose (0.3-3.21%. The predominant fatty acid of the lipid fraction from the durian seed gum were palmitic acid (C16:0, palmitoleic acid (C16:1, stearic acid (C18:0, oleic acid (C18:1, linoleic acid (C18:2, and linolenic acid (C18:2. The most abundant amino acids of durian seed gum were: leucine (30.9-37.3%, lysine (6.04-8.36%, aspartic acid (6.10-7.19%, glycine (6.07-7.42%, alanine (5.24-6.14%, glutamic acid (5.57-7.09%, valine (4.5-5.50%, proline (3.87-4.81%, serine (4.39-5.18%, threonine (3.44-6.50%, isoleucine (3.30-4.07%, and phenylalanine (3.11-9.04%. Conclusion The presence of essential amino acids in the chemical structure of durian seed gum reinforces its nutritional value.

  11. Biopolymer electrolytes based on blend of kappa-carrageenan and cellulose derivatives for potential application in dye sensitized solar cell

    International Nuclear Information System (INIS)

    Rudhziah, S.; Ahmad, A.; Ahmad, I.; Mohamed, N.S.

    2015-01-01

    In this work, carboxymethyl kappa-carrageenan was used as the principle host for developing new biopolymer electrolytes based on the blend of carboxymethyl kappa-carrageenan/carboxymethyl cellulose. The blending of carboxymethyl cellulose into carboxymethyl kappa-carragenan was found to be a promising strategy to improve the material properties such as conductive properties. The electrolyte samples were characterized using Fourier transform infrared spectroscopy, scanning electron microscopy, dynamic mechanical analysis, electrochemical impedance spectroscopy, ionic transference number measurement and linear sweep voltammetry in order to investigate their structural, thermal and electrochemical properties. Impedance study showed that the ionic conductivity increased with the increment of ammonium iodide concentration. The highest room temperature ionic conductivity achieved was 2.41 × 10 −3 S cm −1 at 30 wt% of the salt. The increment of conductivity was due to the increase of formation of transient cross-linking between the carboxymethyl kappa-carrageenan/carboxymethyl cellulose chains and the doping salt as indicated the T g trend. The conductivity was also attributed by the increase in the number of charge carriers in the biopolymer electrolytes system. The interactions between polymers and salt were confirmed by FTIR study. The transference number measurements showed that the conductivity was predominantly ionic. Temperature dependent conductivity study showed that conductivity increased with the reciprocal of temperature. The conductivity-temperature plots suggested that the conductivity obeyed the Vogel–Tammann–Fulcher relation and the activation energy for the best conducting sample was 0.010 eV. This system was used for the fabrication of dye sensitized solar cells, FTO/TiO 2 -dye/CMKC/CMCE-NH 4 I + I 2 /Pt. The fabricated cell showed response under light intensity of 100 mW cm −2 with efficiency of 0.13% indicating that the blend biopolymer

  12. Rapid communication: Computational simulation and analysis of a candidate for the design of a novel silk-based biopolymer.

    Science.gov (United States)

    Golas, Ewa I; Czaplewski, Cezary

    2014-09-01

    This work theoretically investigates the mechanical properties of a novel silk-derived biopolymer as polymerized in silico from sericin and elastin-like monomers. Molecular Dynamics simulations and Steered Molecular Dynamics were the principal computational methods used, the latter of which applies an external force onto the system and thereby enables an observation of its response to stress. The models explored herein are single-molecule approximations, and primarily serve as tools in a rational design process for the preliminary assessment of properties in a new material candidate. © 2014 Wiley Periodicals, Inc.

  13. Characterization of cross-linked porous gelatin carriers and their interaction with corneal endothelium: biopolymer concentration effect.

    Directory of Open Access Journals (Sweden)

    Jui-Yang Lai

    Full Text Available Cell sheet-mediated tissue regeneration is a promising approach for corneal reconstruction. However, the fragility of bioengineered corneal endothelial cell (CEC monolayers allows us to take advantage of cross-linked porous gelatin hydrogels as cell sheet carriers for intraocular delivery. The aim of this study was to further investigate the effects of biopolymer concentrations (5-15 wt% on the characteristic and safety of hydrogel discs fabricated by a simple stirring process combined with freeze-drying method. Results of scanning electron microscopy, porosity measurements, and ninhydrin assays showed that, with increasing solid content, the pore size, porosity, and cross-linking index of carbodiimide treated samples significantly decreased from 508±30 to 292±42 µm, 59.8±1.1 to 33.2±1.9%, and 56.2±1.6 to 34.3±1.8%, respectively. The variation in biopolymer concentrations and degrees of cross-linking greatly affects the Young's modulus and swelling ratio of the gelatin carriers. Differential scanning calorimetry measurements and glucose permeation studies indicated that for the samples with a highest solid content, the highest pore wall thickness and the lowest fraction of mobile water may inhibit solute transport. When the biopolymer concentration is in the range of 5-10 wt%, the hydrogels have high freezable water content (0.89-0.93 and concentration of permeated glucose (591.3-615.5 µg/ml. These features are beneficial to the in vitro cultivation of CECs without limiting proliferation and changing expression of ion channel and pump genes such as ATP1A1, VDAC2, and AQP1. In vivo studies by analyzing the rabbit CEC morphology and count also demonstrate that the implanted gelatin discs with the highest solid content may cause unfavorable tissue-material interactions. It is concluded that the characteristics of cross-linked porous gelatin hydrogel carriers and their triggered biological responses are in relation to biopolymer

  14. Oxidation of alginate and pectate biopolymers by cerium(IV) in perchloric and sulfuric acid solutions: A comparative kinetic and mechanistic study.

    Science.gov (United States)

    Fawzy, Ahmed

    2016-03-15

    The kinetics of oxidation of alginate (Alg) and pectate (Pec) carbohydrate biopolymers was studied by spectrophotometry in aqueous perchloric and sulfuric acid solutions at fixed ionic strengths and temperature. In both acids, the reactions showed a first order dependence on [Ce(IV)], whereas the orders with respect to biopolymer concentrations are less than unity. In perchloric acid, the reactions exhibited less than unit orders with respect to [H(+)] whereas those proceeded in sulfuric acid showed negative fractional-first order dependences on [H(+)]. The effect of ionic strength and dielectric constant was studied. Probable mechanistic schemes for oxidation reactions were proposed. In both acids, the final oxidation products were characterized as mono-keto derivatives of both biopolymers. The activation parameters with respect to the slow step of the mechanisms were computed and discussed. The rate laws were derived and the reaction constants involved in the different steps of the mechanisms were calculated. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. Barrier, structural and mechanical properties of bovine gelatin-chitosan blend films related to biopolymer interactions.

    Science.gov (United States)

    Benbettaïeb, Nasreddine; Kurek, Mia; Bornaz, Salwa; Debeaufort, Frédéric

    2014-09-01

    The increased use of synthetic packaging films has led to a high ecological problem due to their total non-biodegradability. Thus, there is a vital need to develop renewable and environmentally friendly bio-based polymeric materials. Films and coatings made from polysaccharide polymers, particularly chitosans and gelatins have good gas barrier properties and are envisaged more and more for applications in the biomedical and food fields, as well as for packaging. In this study a casting method was used to develop an edible plasticised film from chitosan and gelatin. Aiming to develop a blend film with enhanced properties, the effects of mixing chitosan (CS) and gelatin (G) in different proportions (CS:G, 75:25, 50:50, 25:75, w/w) on functional and physico-chemical properties have been studied. Mean film thickness increased linearly (R2 =0.999) with surface density of the film forming solution. An enhancement of mechanical properties by increasing the tensile strength (38.7±11 MPa for pure chitosan and 76.8±9 MPa for pure gelatin film) was also observed in blends, due to gelatin content.When the gelatin content in blend filmswas increased an improvement of both water vapour barrier properties [(4±0.3)×10(-10) g m(-1) s(-1) Pa(-1) for pure chitosan and (2.5±0.14)×10(-10) g m(-1) s(-1) Pa(-1) for pure gelatin, at 70% RH gradient] and oxygen barrier properties ((822.62±90.24)×10(-12) g m(-1) s(-1) Pa(-1) for blend film chitosan:gelatin (25:75 w/w) and (296.67±18.76)×10(-12) g m(-1) s(-1) Pa(-1) for pure gelatin was observed. Fourier transform infrared spectra of blend films showed a shift in the peak positions related to the amide groups (amide-I and amide-III) indicating interactions between biopolymers. Addition of gelatin in chitosan induced greater functional properties (mechanical, barrier) due to chemical interactions, suggesting an inter-penetrated network. © 2014 Society of Chemical Industry.

  16. Ultrasound treated potato peel and sweet lime pomace based biopolymer film development.

    Science.gov (United States)

    Borah, Purba Prasad; Das, Pulak; Badwaik, Laxmikant S

    2017-05-01

    Treatment and management of food processing waste is a major challenge for food industry. Potato processing industry generates tremendous amount of peel and consider it as zero valued waste. Again, pomace generated after juice extraction from sweet lime pulp is considered as waste and not properly utilized. Whereas these waste could be utilized for the development of biodegradable packaging film to overcome environmental issues. Composite films were prepared with varying proportion of potato peel powder (PP) and sweet lime pomace (SLP) in the ratio of 0:1(A), 0.5:1(B), 1:1(C), 1:0.5(D), 1:0(E) with an ultrasound treatment of 45min, and 0:1(F), 0.5:1(G), 1:1(H), 1:0.5(I), 1:0(J) with an ultrasound treatment of 60min. Ultrasound was applied for 45 and 60min to film forming solutions to break down biopolymer particles small enough to form a film. All the films were analyzed for their barrier and mechanical properties. It was observed that increasing ultrasound treatment times gives better result in film properties and less PP content also gives better film properties, from these observations film G prepared with 0.5:1 (PP:SLP) showed better characteristics among all other films. Water vapor permeability, moisture absorption, water solubility, breakage strength and elongation capacity of G film were reported as 7.25×10 -9 g/Pahm, 12.88±0.348%, 38.92±0.702%, 242.01±3.074g and 7.61±0.824mm respectively. However, thermal decomposition for film G took place above 200°C. The film forming solution of selected G film, added with clove essential oil (1.5%) as an antimicrobial agent was wrapped on bread and stored it for 5days. The film was successful in lowering the weight loss, reducing the hardness and inhibition of surface microbial load from bread sample. Copyright © 2016 Elsevier B.V. All rights reserved.

  17. Solid-State (13)C NMR Delineates the Architectural Design of Biopolymers in Native and Genetically Altered Tomato Fruit Cuticles.

    Science.gov (United States)

    Chatterjee, Subhasish; Matas, Antonio J; Isaacson, Tal; Kehlet, Cindie; Rose, Jocelyn K C; Stark, Ruth E

    2016-01-11

    Plant cuticles on outer fruit and leaf surfaces are natural macromolecular composites of waxes and polyesters that ensure mechanical integrity and mitigate environmental challenges. They also provide renewable raw materials for cosmetics, packaging, and coatings. To delineate the structural framework and flexibility underlying the versatile functions of cutin biopolymers associated with polysaccharide-rich cell-wall matrices, solid-state NMR spectra and spin relaxation times were measured in a tomato fruit model system, including different developmental stages and surface phenotypes. The hydrophilic-hydrophobic balance of the cutin ensures compatibility with the underlying polysaccharide cell walls; the hydroxy fatty acid structures of outer epidermal cutin also support deposition of hydrophobic waxes and aromatic moieties while promoting the formation of cell-wall cross-links that rigidify and strengthen the cuticle composite during fruit development. Fruit cutin-deficient tomato mutants with compromised microbial resistance exhibit less efficient local and collective biopolymer motions, stiffening their cuticular surfaces and increasing their susceptibility to fracture.

  18. Column adsorption of perchlorate by amine-crosslinked biopolymer based resin and its biological, chemical regeneration properties.

    Science.gov (United States)

    Song, Wen; Xu, Xing; Tan, Xin; Wang, Yan; Ling, Jianya; Gao, Baoyu; Yue, Qinyan

    2015-01-22

    Column adsorption of perchlorate by amine-crosslinked biopolymer based resin was investigated by considering the bed depth, stream flow rate and influent pH. The empty bed contact time (EBCT) increased with the growth of bed depths, meanwhile rising flow rate at constant bed depth (3.4 cm) decreased the breakthrough time. It was observed that perchlorate adsorption capacity was optimum at neutral condition (pH: 6.0, 170.4 mg/g), and decreased at acidic (pH: 3.0, 96.4 mg/g) or alkalic (pH: 12.0, 72.8 mg/g) influents. The predominant strains of the acclimated sludge for resin biological regeneration were the β-subclass of Proteobacteria. Biological regeneration of the saturated amine-crosslinked biopolymer based resin with mixed bacteria have shown its merit with regeneration and biological perchlorate destruction simultaneously, although its regeneration efficiency was only 61.2-84.1% by contrast to chemical regeneration with efficiency more than 95%. Copyright © 2014 Elsevier Ltd. All rights reserved.

  19. Nonlinear optical probe of biopolymer adsorption on colloidal particle surface: poly-L-lysine on polystyrene sulfate microspheres.

    Science.gov (United States)

    Eckenrode, Heather M; Dai, Hai-Lung

    2004-10-12

    A nonlinear optical technique--second harmonic generation (SHG)--has been applied to characterize the adsorption of poly-L-lysine on micrometer size polystyrene particles, whose surface is covered with negatively charged sulfonate groups, in aqueous solutions. Adsorption behavior of the biopolymer with two chain lengths (14 and 75 amino acid units; PL14 and PL75) has been examined. Centrifugation experiments were also performed to support the adsorption measurements made using SHG. The adsorption free energies of the two polymers PL75 and PL14 are determined as -16.57 and -14.40 kcal/mol, respectively. The small difference in the adsorption free energies of the two chain lengths, however, leads to dramatic difference in the concentration needed for saturated surface coverage: nearly 50 times higher concentration is needed for the smaller polymer. Under acidic colloidal conditions, polylysine is found to adsorb in a relatively flat conformation on the surface. The surface area that each polylysine molecule occupies is nearly 1 order of magnitude larger than the size of the molecule in its extended form. The low adsorption density is likely a result from Coulombic repulsion between the positive charges on the amino acid units of PL. The measurements demonstrate the utility of SHG as an efficient and sensitive experimental approach for measuring adsorption characteristics of bio/macromolecules on colloidal particles and define surface and colloidal conditions for achieving maximum surface coverage of a widely used biopolymer. Copyright 2004 American Chemical Society

  20. The role of printing parameters and scaffold biopolymer properties in the efficacy of a new hybrid nano-bioprinting system

    Energy Technology Data Exchange (ETDEWEB)

    Buyukhatipoglu, Kivilcim; Jo, Wonjin; Sun Wei; Clyne, Alisa Morss, E-mail: asm67@drexel.ed [Mechanical Engineering and Mechanics, Drexel University, 3141 Chestnut Street, Philadelphia, PA 19104 (United States)

    2009-09-15

    We created a hybrid nano-bioprinting system, which combines the initial patterning capabilities of direct cell writing with the active patterning capabilities of superparamagnetic nanoparticles. Biofabrication conditions, including printing parameters and scaffold biopolymer properties, may affect cell viability, nanoparticle manipulation and patterning capabilities. Nanoparticles were printed under varied conditions either in the biopolymer or loaded inside cells. Cell viability, alginate viscosity, nanoparticle movement and printing resolution were measured. We now show that while nanoparticles decreased cell viability, nozzle size had no significant effect. High printing pressure decreased cell viability, but viability loss was not accentuated by nanoparticles. High nanoparticle concentrations increased alginate viscosity at higher alginate concentrations. Nanoparticle velocity in response to a magnetic field was a function of nanoparticle diameter and scaffold viscosity, which agreed with a mathematical model of nanoparticle movement. Finally, the nano-bioprinting system resolution and patterning precision were not affected by nanoparticles in the prepolymer solution. These data suggest that nanoparticle incorporation in solid freeform fabrication does not change biofabrication parameters unless high nanoparticle concentrations are used. Future work includes developing vascularized tissue engineering constructs using the nano-bioprinting system.

  1. The role of printing parameters and scaffold biopolymer properties in the efficacy of a new hybrid nano-bioprinting system

    International Nuclear Information System (INIS)

    Buyukhatipoglu, Kivilcim; Jo, Wonjin; Sun Wei; Clyne, Alisa Morss

    2009-01-01

    We created a hybrid nano-bioprinting system, which combines the initial patterning capabilities of direct cell writing with the active patterning capabilities of superparamagnetic nanoparticles. Biofabrication conditions, including printing parameters and scaffold biopolymer properties, may affect cell viability, nanoparticle manipulation and patterning capabilities. Nanoparticles were printed under varied conditions either in the biopolymer or loaded inside cells. Cell viability, alginate viscosity, nanoparticle movement and printing resolution were measured. We now show that while nanoparticles decreased cell viability, nozzle size had no significant effect. High printing pressure decreased cell viability, but viability loss was not accentuated by nanoparticles. High nanoparticle concentrations increased alginate viscosity at higher alginate concentrations. Nanoparticle velocity in response to a magnetic field was a function of nanoparticle diameter and scaffold viscosity, which agreed with a mathematical model of nanoparticle movement. Finally, the nano-bioprinting system resolution and patterning precision were not affected by nanoparticles in the prepolymer solution. These data suggest that nanoparticle incorporation in solid freeform fabrication does not change biofabrication parameters unless high nanoparticle concentrations are used. Future work includes developing vascularized tissue engineering constructs using the nano-bioprinting system.

  2. Surface changes of biopolymers PHB and PLLA induced by Ar{sup +} plasma treatment and wet etching

    Energy Technology Data Exchange (ETDEWEB)

    Slepičková Kasálková, N. [Department of Solid State Engineering, Institute of Chemical Technology, 166 28 Prague (Czech Republic); Slepička, P., E-mail: petr.slepicka@vscht.cz [Department of Solid State Engineering, Institute of Chemical Technology, 166 28 Prague (Czech Republic); Sajdl, P. [Department of Power Engineering, Institute of Chemical Technology, 166 28 Prague (Czech Republic); Švorčík, V. [Department of Solid State Engineering, Institute of Chemical Technology, 166 28 Prague (Czech Republic)

    2014-08-01

    Polymers, especially group of biopolymers find potential application in a wide range of disciplines due to their biodegradability. In biomedical applications these materials can be used as a scaffold or matrix. In this work, the influence of the Ar{sup +} plasma treatment and subsequent wet etching (acetone/water) on the surface properties of polymers were studied. Two biopolymers – polyhydroxybutyrate with 8% polyhydroxyvalerate (PHB) and poly-L-lactic acid (PLLA) were used in these experiments. Modified surface layers were analyzed by different methods. Surface wettability was characterized by determination of water contact angle. Changes in elemental composition of modified surfaces were performed by X-ray Photoelectron Spectroscopy (XPS). Surface morphology and roughness was examined using Atomic Force Microscopy (AFM). Gravimetry method was used to study the mass loss. It was found that the modification from both with plasma and wet etching leads to dramatic changes of surface properties (surface chemistry, morphology and roughness). Rate of changes of these features strongly depends on the modification parameters.

  3. Effective recovery of poly-β-hydroxybutyrate (PHB) biopolymer from Cupriavidus necator using a novel and environmentally friendly solvent system.

    Science.gov (United States)

    Fei, Tao; Cazeneuve, Stacy; Wen, Zhiyou; Wu, Lei; Wang, Tong

    2016-05-01

    This work demonstrates a significant advance in bioprocessing for a high-melting lipid polymer. A novel and environmental friendly solvent mixture, acetone/ethanol/propylene carbonate (A/E/P, 1:1:1 v/v/v) was identified for extracting poly-hydroxybutyrate (PHB), a high-value biopolymer, from Cupriavidus necator. A set of solubility curves of PHB in various solvents was established. PHB recovery of 85% and purity of 92% were obtained from defatted dry biomass (DDB) using A/E/P. This solvent mixture is compatible with water, and from non-defatted wet biomass, PHB recovery of 83% and purity of 90% were achieved. Water and hexane were evaluated as anti-solvents to assist PHB precipitation, and hexane improved recovery of PHB from biomass to 92% and the purity to 93%. A scale-up extraction and separation reactor was designed, built and successfully tested. Properties of PHB recovered were not significantly affected by the extraction solvent and conditions, as shown by average molecular weight (1.4 × 10(6) ) and melting point (175.2°C) not being different from PHB extracted using chloroform. Therefore, this biorenewable solvent system was effective and versatile for extracting PHB biopolymers. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 32:678-685, 2016. © 2016 American Institute of Chemical Engineers.

  4. Phase distribution of products of radiation and post-radiation distillation of biopolymers: Cellulose, lignin and chitin

    International Nuclear Information System (INIS)

    Ponomarev, A.V.; Kholodkova, E.M.; Metreveli, A.K.; Metreveli, P.K.; Erasov, V.S.; Bludenko, A.V.; Chulkov, V.N.

    2011-01-01

    Influence of both the absorbed dose and the dose rate of 8 MeV electron-beam radiation on destruction of microcrystalline cellulose, pine lignin and krill chitin was investigated. Two conversion modes were compared: (1) post-radiation distillation PRD and (2) electron-beam distillation EBD. Cellulose, chitin and lignin demonstrate different responses to irradiation and distillation in PRD and EBD modes. Treatment in EBD mode transforms biopolymers to organic liquid more productively than conventional dry distillation and treatment in PRD mode. Both radiation heating and an irradiation without heating intensify chitin and cellulose decomposition and distillation. At the same time lignin decaying rather efficiently in EBD mode appears to be insensitive to a preliminary irradiation in PRD mode up to a dose of 2.4 MGy. - Highlights: → Direct conversion of cellulose, chitin and lignin to organic liquid is intensified by electron-beam irradiation. → Alternative approach to bio-oil production. → Both electron-beam distillation mode and post-radiation distillation mode are effective for cellulose and chitin conversion. → Electron-beam distillation mode is preferable for lignin conversion. → Preliminary deep dehydration of biopolymers is realizable at low dose rates.

  5. Layer-by-layer assembled biopolymer microcapsule with separate layer cavities generated by gas-liquid microfluidic approach.

    Science.gov (United States)

    Wang, Yifeng; Zhou, Jing; Guo, Xuecheng; Hu, Qian; Qin, Chaoran; Liu, Hui; Dong, Meng; Chen, Yanjun

    2017-12-01

    In this work, a layer-by-layer (LbL) assembled biopolymer microcapsule with separate layer cavities is generated by a novel and convenient gas-liquid microfluidic approach. This approach exhibits combined advantages of microfluidic approach and LbL assembly method, and it can straightforwardly build LbL-assembled capsules in mild aqueous environments at room temperature. In particular, using this approach we can build the polyelectrolyte multilayer capsule with favorable cavities in each layer, and without the need for organic solvent, emulsifying agent, or sacrificial template. Various components (e.g., drugs, proteins, fluorescent dyes, and nanoparticles) can be respectively encapsulated in the separate layer cavities of the LbL-assembled capsules. Moreover, the encapsulated capsules present the ability as colorimetric sensors, and they also exhibit the interesting release behavior. Therefore, the LbL-assembled biopolymer capsule is a promising candidate for biomedical applications in targeted delivery, controlled release, and bio-detection. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. Relevant insight of surface characterization techniques to study covalent grafting of a biopolymer to titanium implant and its acidic resistance

    Science.gov (United States)

    D'Almeida, Mélanie; Amalric, Julien; Brunon, Céline; Grosgogeat, Brigitte; Toury, Bérangère

    2015-02-01

    Peri-implant bacterial infections are the main cause of complications in dentistry. Our group has previously proposed the attachment of chitosan on titanium implants via a covalent bond to improve its antibacterial properties while maintaining its biocompatibility. A better knowledge of the coating preparation process allows a better understanding of the bioactive coating in biological conditions. In this work, several relevant characterization techniques were used to assess an implant device during its production phase and its resistance in natural media at different pH. The titanium surface was functionalized with 3-aminopropyltriethoxysilane (APTES) followed by grafting of an organic coupling agent; succinic anhydride, able to form two covalent links, with the substrate through a Ti-O-Si bond and the biopolymer through a peptide bond. Each step of the coating synthesis as well as the presence confirmation of the biopolymer on titanium after saliva immersion was followed by FTIR-ATR, SEM, EDS, 3D profilometry, XPS and ToF-SIMS analyses. Results allowed to highlight the efficiency of each step of the process, and to propose a mechanism occurring during the chitosan coating degradation in saliva media at pH 5 and at pH 3.

  7. Hemostatic, antibacterial biopolymers from Acacia arabica (Lam.) Willd. and Moringa oleifera (Lam.) as potential wound dressing materials.

    Science.gov (United States)

    Bhatnagar, Monica; Parwani, Laxmi; Sharma, Vinay; Ganguli, Jhuma; Bhatnagar, Ashish

    2013-10-01

    Acacia arabica and Moringa oleifera are credited with a number of medicinal properties. Traditionally gum of Acacia plant is used in the treatment of skin disorders to soothe skin rashes, soreness, inflammation and burns while Moringa seed extracts are known to have antibacterial activity. In the present study the potential of the polymeric component of aqueous extracts of gum acacia (GA) and the seeds of M. oleifera (MSP) in wound management was evaluated. The results revealed that both biopolymers were hemostatic and hasten blood coagulation. They showed shortening of activated partial thromboplastin time and prothrombin time and were non-cytotoxic in nature. Both showed antibacterial activity against organisms known to be involved in wound infections with MIC ranging from 500-600 microg mL(-1) for GA and 300-700 microg mL(-1) for MSP. They were biodegradable and exhibited water absorption capacity in the range of 415 to 935%. The hemostatic character coupled to these properties envisions their potential in preparation of dressings for bleeding and profusely exuding wounds. The biopolymers have been further analysed for their composition by Gas chromatography.

  8. Importance of coccolithophore-associated organic biopolymers for fractionating particle-reactive radionuclides (234Th, 233Pa, 210Pb, 210Po, and 7Be) in the ocean

    Science.gov (United States)

    Lin, Peng; Xu, Chen; Zhang, Saijin; Sun, Luni; Schwehr, Kathleen A.; Bretherton, Laura; Quigg, Antonietta; Santschi, Peter H.

    2017-08-01

    Laboratory incubation experiments using the coccolithophore Emiliania huxleyi were conducted in the presence of 234Th, 233Pa, 210Pb, 210Po, and 7Be to differentiate radionuclide uptake to the CaCO3 coccosphere from coccolithophore-associated biopolymers. The coccosphere (biogenic calcite exterior and its associated biopolymers), extracellular (nonattached and attached exopolymeric substances), and intracellular (sodium-dodecyl-sulfate extractable and Fe-Mn-associated metabolites) fractions were obtained by sequentially extraction after E. huxleyi reached its stationary growth phase. Radionuclide partitioning and the composition of different organic compound classes, including proteins, total carbohydrates (TCHO), and uronic acids (URA), were assessed. 210Po was closely associated with the more hydrophobic biopolymers (high protein/TCHO ratio, e.g., in attached exopolymeric substances), while 234Th and 233Pa showed similar partitioning behavior with most activity being distributed in URA-enriched, nonattached exopolymeric substances and intracellular biopolymers. 234Th and 233Pa were nearly undetectable in the coccosphere, with a minor abundance of organic components in the associated biopolymers. These findings provide solid evidence that biogenic calcite is not the actual main carrier phase for Th and Pa isotopes in the ocean. In contrast, both 210Pb and 7Be were found to be mostly concentrated in the CaCO3 coccosphere, likely substituting for Ca2+ during coccolith formation. Our results demonstrate that even small cells (E. huxleyi) can play an important role in the scavenging and fractionation of radionuclides. Furthermore, the distinct partitioning behavior of radionuclides in diatoms (previous studies) and coccolithophores (present study) explains the difference in the scavenging of radionuclides between diatom- and coccolithophore-dominated marine environments.

  9. Novel Proton Conducting Solid Bio-polymer Electrolytes Based on Carboxymethyl Cellulose Doped with Oleic Acid and Plasticized with Glycerol

    Science.gov (United States)

    Chai, M. N.; Isa, M. I. N.

    2016-06-01

    The plasticized solid bio-polymer electrolytes (SBEs) system has been formed by introducing glycerol (Gly) as the plasticizer into the carboxymethyl cellulose (CMC) doped with oleic acid (OA) via solution casting techniques. The ionic conductivity of the plasticized SBEs has been studied using Electrical Impedance Spectroscopy. The highest conductivity achieved is 1.64 × 10-4 S cm-1 for system containing 40 wt. % of glycerol. FTIR deconvolution technique had shown that the conductivity of CMC-OA-Gly SBEs is primarily influenced by the number density of mobile ions. Transference number measurement has shown that the cation diffusion coefficient and ionic mobility is higher than anion which proved the plasticized polymer system is a proton conductor.

  10. Radioprotective influence on mice DNA of biopolymer complexes from tinder Fomes Fomentarius under ionizing radiation in small doses

    Directory of Open Access Journals (Sweden)

    O. F. Seniuk

    2014-03-01

    Full Text Available The effects of similar doses of the values of common external irradiation (0,19 Gy/4hours and 0,24 Gy/6 months at single-strand DNA breaks and the level of the hydrogen bonds in this molecule in different cell types (lymphocytes, hepatocytes and splenocytes linear mice CC57W/mv are discussed. Mice were exposed to γ-fields produced by “hot” particles of emergency 4-th Chernobyl Unit containing the same radionuclides in the proportions. The possibility of leveling the radiation effects using complex biopolymers from Fomes fomentarius was shown. The ability of melanin-glucan complex to directly counteract the fragmentation of DNA in a model system with lambda phage this macromolecule oxidation products of benzidine and neutralize mutagenic effect in Salmonella typhimurium strains in the classical Ames test was studied.

  11. Radioprotective influence on mice DNA of biopolymer complexes from tinder Fomes Fomentarius under ionizing radiation in small doses

    International Nuclear Information System (INIS)

    Senyuk, O.F.; Koval'ov, O.V.; Palamar, L.A.; Krul', M.Yi.; Gorovij, L.F.

    2014-01-01

    The effects of similar doses of the values of common external irradiation (0,19 Gy/4 hours and 0,24 Gy/6 months) at single-strand DNA breaks and the level of the hydrogen bonds in this molecule in different cell types (lymphocytes, hepatocytes and splenocytes) linear mice CC57W/mv are discussed. Mice were exposed to γ-fields produced by h ot - particles of emergency 4-th Chernobyl Unit containing the same radionuclides in the proportions. The possibility of leveling the radiation effects using complex biopolymers from Fomes Fomentarius was shown. The ability of melanin-glucan complex to directly counteract the fragmentation of DNA in a model system with lambda phage this macromolecule oxidation products of benzidine and neutralize mutagenic effect in Salmonella typhimurium strains in the classical Ames test was studied

  12. Change in the fouling propensity of sludge in membrane bioreactors (MBR) in relation to the accumulation of biopolymer clusters.

    Science.gov (United States)

    Sun, Fei-yun; Wang, Xiao-mao; Li, Xiao-yan

    2011-04-01

    A membrane bioreactor (MBR) and an activated sludge process (ASP) were operated side by side to evaluate the change of sludge supernatant characteristics and the evolution of the sludge fouling propensity. The MBR sludge had a higher organic concentration and more biopolymer clusters (BPC) in the supernatant compared with ASP. BPC increased in both concentration and size in the MBR. The results show that the change in the liquid-phase property had a profound effect on the sludge fouling propensity. MBR operation transformed typical activated sludge to MBR sludge with a higher fouling propensity. Distinct from the ASP, membrane filtration retained soluble microbial products (SMP) within the MBR, and the vast membrane surface provided a unique environment for the transformation of SMP to large size BPC, leading to further sludge deposition on the membrane surface. Thus, membrane filtration is the crucial cause of the inevitable fouling problem in submerged MBRs. Copyright © 2011 Elsevier Ltd. All rights reserved.

  13. Use of gamma-irradiation technology in the manufacture of biopolymer-based packaging films for shelf-stable foods

    International Nuclear Information System (INIS)

    Parra, Duclerc F.; Rodrigues, Juliana A.F.R.; Lugao, Ademar B.

    2005-01-01

    Gamma irradiation is an alternative method for the manufacture of sterilized packaging with increased storage stability and microbiological safety. Biopolymer-based packaging films are a potential solution to many environmental problems that have emerged from the production and accumulation of significant amounts of synthetic polymeric waste. This work was undertaken to verify the effectiveness of low-dose gamma-irradiation in obtaining biopolymer-based packaging films for shelf-stable foods. PHB polyester poly(3-hydroxybutyrate) is an interesting biodegradable polymer that has been intensely investigated as cast and sheet films, with applications in the food industry and medicine. The films obtained are, however, typically brittle, and many scientists have attempted to reduce this brittleness by blending PHB with other polymers. In the present work, PHB was blended with PEG (polyethyleneglycol) to obtain films by the casting method that were then irradiated at a dose rate of 5.72 kGy/h with a 60 Co source. Samples were melted at 200 deg. C and quenched to 0 deg. C in order to evaluate film crystallinity levels by differential scanning calorimetry (DSC). DSC analyses were performed with the samples (10 mg) under N 2 atmosphere, heating from -50 to 200 deg. C (10 deg. C min -1 ), cooling from 200 to -50 deg. C (10 deg. C min -1 ); and heating from -50 to 200 deg. C (10 deg. C min -1 ). The thermal and mechanical resistances of the films after irradiation at low doses (5, 10, 20 kGy) are discussed. Water vapour transmission decreased with increasing irradiation dose, indicating that the films' performance as water vapour barrier had improved. Critical loss of the mechanical properties was observed at 40 kGy

  14. Development of pH-responsive biopolymer-silica composites loaded with Larrea divaricata Cav. extract with antioxidant activity.

    Science.gov (United States)

    Alvarez Echazú, María Inés; Olivetti, Christian Ezequiel; Peralta, Ignacio; Alonso, Maria Rosario; Anesini, Claudia; Perez, Claudio Javier; Alvarez, Gisela Solange; Desimone, Martin Federico

    2018-05-07

    A detailed study of biomaterials is mandatory to comprehend their feasible biomedical applications in terms of drug delivery and tissue regeneration. Particularly, mucoadhesive biopolymers such as chitosan (chi) and carboxymethylcellulose (CMC) have become interesting biomaterials regards to their biocompatibility and non-toxicity for oral mucosal drug delivery. In this work, pH-responsive biopolymer-silica composites (Chi-SiO 2 , Chi-CMC-SiO 2 ) were developed. These two types of composites presented a different swelling behavior due to the environmental pH. Moreover, the nanocomposites were loaded with aqueous Larrea divaricata Cav. extract (Ld), a South American plant which presents antioxidant properties suitable for the treatment of gingivoperiodontal diseases. Chi-CMC-SiO 2 composites showed the highest incorporation and reached the 100% of extract release in almost 4 days while they preserved their antioxidant properties. In this study, thermal and swelling behavior were pointed out to show the distinct water-composite interaction and therefore to evaluate their mucoadhesivity. Furthermore, a cytotoxicity test with 3T3 fibroblasts was assessed, showing that in both composites the addition of Larrea divaricata Cav. extract increased fibroblast proliferation. Lastly, preliminary in vitro studies were performed with simulated body fluids. Indeed, SEM-EDS analysis indicated that only chi-SiO 2 composite may provide an environment for possible biomineralization while the addition of CMC to the composites discouraged calcium accumulation. In conclusion, the development of bioactive composites could promote the regeneration of periodontal tissue damaged throughout periodontal disease and the presence of silica nanoparticles could provide an environment for biomineralization. Copyright © 2018 Elsevier B.V. All rights reserved.

  15. Study of Thermal Properties, Turbidity, Effective Factors on Particle Size and Oscillatory Rheology of Pectin-Caseinate Biopolymer Nanocomplexes

    Directory of Open Access Journals (Sweden)

    Sajedeh Bahrani

    2013-02-01

    Full Text Available The biopolymer-based nanocomplexes are a group of nanocapsules that are used for encapsulation and control delivery of nutraceuticals. They are formed by binding of proteins and polysaccharides. In this study, complex formation between pectin and sodium caseinate was taken place by addition of pectin solutions(0.2, 0.45 and 0.7 % w/v into the caseinate solutions (0.5, 1 and 1.5 % w/v and adjusted their pH below isoelecteric point of sodium caseinate. The effect of various factors such as biopolymer concentration, salt concentration, temperature and time of ultrasound on the properties of pectin-casein nanocomplexes was investigated. Differential scanning calorimetry (DSC and particle size analyzer were used for study of complex formation and particle size determination, respectively. The results of DSC and turbidimetry showed complex formation between the pectin and casein at pH below 5 and the results of particle size showed formation of stable dispersion with a minimum size of 86 nm at pH 4.1, caseinate of 1 % w/v and pectin 0.45 % w/v concentration. The ultrasound for more than 1 min reduced particle size and addition of salt at high and low concentrations had different effects on the stability of the colloidal system. The lowering of temperature from 21 to 4°C resulted in smaller particle size of nanocomplexes. The oscillatory rheological results showed that with increasing pectin concentration, viscoelastic moduli were increased and loss moduli were higher than storage modulus.

  16. Preparation of Nano-Scale Biopolymer Extracted from Coconut Residue and Its Performance as Drag Reducing Agent (DRA

    Directory of Open Access Journals (Sweden)

    Hasan Muhammad Luqman Bin

    2017-01-01

    Full Text Available Drag or frictional force is defined as force that acts opposite to the object’s relative motion through a fluid which then will cause frictional pressure loss in the pipeline. Drag Reducing Agent (DRA is used to solve this issue and most of the DRAs are synthetic polymers but has some environmental issues. Therefore for this study, biopolymer known as Coconut Residue (CR is selected as the candidate to replace synthetic polymers DRA. The objective of this study is to evaluate the effectiveness of Nano-scale biopolymer DRA on the application of water injection system. Carboxymethyl cellulose (CMC is extracted by synthesizing the cellulose extracted from CR under the alkali-catalyzed reaction using monochloroacetic acid. The synthesize process is held in controlled condition whereby the concentration of NaOH is kept at 60%wt, 60 °C temperature and the reaction time is 4 hours. For every 25 g of dried CR used, the mass of synthesized CMC yield is at an average of 23.8 g. The synthesized CMC is then grinded in controlled parameters using the ball milling machine to get the Nano-scale size. The particle size obtained from this is 43.32 Nm which is in range of Nano size. This study proved that Nano-size CMC has higher percentage of drag reduction (%DR and flow increase (%FI if compared to normal-size CMC when tested in high and low flow rate; 44% to 48% increase in %DR and %FI when tested in low flow rate, and 16% to 18% increase in %DR and %FI when tested in high flow rate. The success of this research shows that Nano-scale DRA can be considered to be used to have better performance in reducing drag.

  17. Use of gamma-irradiation technology in the manufacture of biopolymer-based packaging films for shelf-stable foods

    Science.gov (United States)

    Parra, Duclerc F.; Rodrigues, Juliana A. F. R.; Lugão, Ademar B.

    2005-07-01

    Gamma irradiation is an alternative method for the manufacture of sterilized packaging with increased storage stability and microbiological safety. Biopolymer-based packaging films are a potential solution to many environmental problems that have emerged from the production and accumulation of significant amounts of synthetic polymeric waste. This work was undertaken to verify the effectiveness of low-dose gamma-irradiation in obtaining biopolymer-based packaging films for shelf-stable foods. PHB polyester poly(3-hydroxybutyrate) is an interesting biodegradable polymer that has been intensely investigated as cast and sheet films, with applications in the food industry and medicine. The films obtained are, however, typically brittle, and many scientists have attempted to reduce this brittleness by blending PHB with other polymers. In the present work, PHB was blended with PEG (polyethyleneglycol) to obtain films by the casting method that were then irradiated at a dose rate of 5.72 kGy/h with a 60Co source. Samples were melted at 200 °C and quenched to 0 °C in order to evaluate film crystallinity levels by differential scanning calorimetry (DSC). DSC analyses were performed with the samples (10 mg) under N2 atmosphere, heating from -50 to 200 °C (10 °C min-1), cooling from 200 to -50 °C (10 °C min-1); and heating from -50 to 200 °C (10 °C min-1). The thermal and mechanical resistances of the films after irradiation at low doses (5, 10, 20 kGy) are discussed. Water vapour transmission decreased with increasing irradiation dose, indicating that the films' performance as water vapour barrier had improved. Critical loss of the mechanical properties was observed at 40 kGy.

  18. The Effect of Multidentate Biopolymer Based on Polyacrylamide Grafted onto Kappa-Carrageenan on the Spectrofluorometric Properties of Water-Soluble CdS Quantum Dots

    Directory of Open Access Journals (Sweden)

    Ghasem Rezanejade Bardajee

    2011-01-01

    Full Text Available A new fluorescent composite based on CdS quantum dots immobilized on the multidentate biopolymer matrix is prepared through the graft copolymerization of the acrylamide onto kappa-Carrageenan. A variety of techniques like thermogravimetric analysis (TGA, transmission electron microscopy (TEM, and Fourier transform infrared spectroscopy (FT-IR was used to confirm the structure of the obtained samples. To investigate the spectrofluorometric properties, fluorescence spectroscopy of the obtained quantum dots was studied.

  19. FS laser processing of bio-polymer thin films for studying cell-to-substrate specific response

    Energy Technology Data Exchange (ETDEWEB)

    Daskalova, A., E-mail: a_daskalova@code.bg [Institute of Electronics, Bulgarian Academy of Sciences, 72, Tsarigradsko Chaussee Blvd., 1784 Sofia (Bulgaria); Nathala, Chandra S.R. [Institute of General Physics, Vienna University of Technology, Wiedner Hauptstr. 8-10/134, A-1040 Wien (Austria); Spectra-Physics Vienna, Fernkorngasse 10, 1100 Wien (Austria); Kavatzikidou, P.; Ranella, A. [Institute for Electronic Structure and Lasers-FORTH, P.O. Box 1385, Vassilika Vouton, 711 10 Heraklion, Crete (Greece); Szoszkiewicz, R. [Faculty of Materials Science and Engineering, Warsaw University of Technology, 141 Woloska Str., 02-507 Warsaw, Poland (Poland); Husinsky, W. [Institute of General Physics, Vienna University of Technology, Wiedner Hauptstr. 8-10/134, A-1040 Wien (Austria); Fotakis, C. [Institute for Electronic Structure and Lasers-FORTH, P.O. Box 1385, Vassilika Vouton, 711 10 Heraklion, Crete (Greece)

    2016-09-30

    Highlights: • Systematic research in the field of fs laser interaction with biopolymers for application in tissue engineering. • Utilizing a new biopolymer blend of collagen/elastin material for studying the interaction process in the fs domain. • Obtaining of improved, circularly shaped, interconnected nanopores, with high reproducibility from collagen/elastin layer. • Observation of randomly arranged pattern outside modification zone due to formation of an impact wave over biofilm surface. • NIH/3T3 cell-interface interaction reveal a preferable cell migration on fs laser-modified surface array. - Abstract: The use of ultra-short pulses for nanoengineering of biomaterials opens up possibilities for biological, medical and tissue engineering applications. Structuring the surface of a biomaterial into arrays with micro- and nanoscale features and architectures, defines new roadmaps to innovative engineering of materials. Thin films of novel collagen/elastin composite and gelatin were irradiated by Ti:sapphire fs laser in air at central wavelength 800 nm, with pulse durations in the range of 30 fs. The size and shape as well as morphological forms occurring in the resulted areas of interaction were analyzed as a function of irradiation fluence and number of pulses by atomic force microscopy (AFM). The fs interaction regime allows generation of well defined micro porous surface arrays. In this study we examined a novel composite consisting of collagen and elastin in order to create a biodegradable matrix to serve as a biomimetic surface for cell attachment. Confocal microscopy images of modified zones reveal formation of surface fringe patterns with orientation direction alongside the area of interaction. Outside the crater rim a wave-like topography pattern is observed. Structured, on a nanometer scale, surface array is employed for cell-culture experiments for testing cell’s responses to substrate morphology. Mice fibroblasts migration was monitored

  20. FS laser processing of bio-polymer thin films for studying cell-to-substrate specific response

    International Nuclear Information System (INIS)

    Daskalova, A.; Nathala, Chandra S.R.; Kavatzikidou, P.; Ranella, A.; Szoszkiewicz, R.; Husinsky, W.; Fotakis, C.

    2016-01-01

    Highlights: • Systematic research in the field of fs laser interaction with biopolymers for application in tissue engineering. • Utilizing a new biopolymer blend of collagen/elastin material for studying the interaction process in the fs domain. • Obtaining of improved, circularly shaped, interconnected nanopores, with high reproducibility from collagen/elastin layer. • Observation of randomly arranged pattern outside modification zone due to formation of an impact wave over biofilm surface. • NIH/3T3 cell-interface interaction reveal a preferable cell migration on fs laser-modified surface array. - Abstract: The use of ultra-short pulses for nanoengineering of biomaterials opens up possibilities for biological, medical and tissue engineering applications. Structuring the surface of a biomaterial into arrays with micro- and nanoscale features and architectures, defines new roadmaps to innovative engineering of materials. Thin films of novel collagen/elastin composite and gelatin were irradiated by Ti:sapphire fs laser in air at central wavelength 800 nm, with pulse durations in the range of 30 fs. The size and shape as well as morphological forms occurring in the resulted areas of interaction were analyzed as a function of irradiation fluence and number of pulses by atomic force microscopy (AFM). The fs interaction regime allows generation of well defined micro porous surface arrays. In this study we examined a novel composite consisting of collagen and elastin in order to create a biodegradable matrix to serve as a biomimetic surface for cell attachment. Confocal microscopy images of modified zones reveal formation of surface fringe patterns with orientation direction alongside the area of interaction. Outside the crater rim a wave-like topography pattern is observed. Structured, on a nanometer scale, surface array is employed for cell-culture experiments for testing cell’s responses to substrate morphology. Mice fibroblasts migration was monitored

  1. Sodium Mercaptoethane Sulfonate Reduces Collagenolytic Degradation and Synergistically Enhances Antimicrobial Durability in an Antibiotic-Loaded Biopolymer Film for Prevention of Surgical-Site Infections

    Directory of Open Access Journals (Sweden)

    Joel Rosenblatt

    2017-01-01

    Full Text Available Implant-associated surgical-site infections can have significant clinical consequences. Previously we reported a method for prophylactically disinfecting implant surfaces in surgical pockets, where an antibiotic solution containing minocycline (M and rifampin (R was applied as a solid film in a crosslinked biopolymer matrix that partially liquefied in situ to provide extended prophylaxis. Here we studied the effect of adding sodium 2-mercaptoethane sulfonate (MeSNA on durability of prophylaxis in an in vitro model of implant-associated surgical-site infection. Adding MeSNA to the M/R biopolymer, antimicrobial film extended the duration for which biofilm formation by multidrug-resistant Pseudomonas aeruginosa (MDR-PA was prevented on silicone surfaces in the model. M/R films with and without MeSNA were effective in preventing colonization by methicillin-resistant Staphylococcus aureus. Independent experiments revealed that MeSNA directly inhibited proteolytic digestion of the biopolymer film and synergistically enhanced antimicrobial potency of M/R against MDR-PA. Incubation of the MeSNA containing films with L929 fibroblasts revealed no impairment of cellular metabolic activity or viability.

  2. Effect of Cross-Linking on the Performances of Starch-Based Biopolymer as Gel Electrolyte for Dye-Sensitized Solar Cell Applications

    Directory of Open Access Journals (Sweden)

    Pavithra Nagaraj

    2017-12-01

    Full Text Available Dye-sensitized solar cells (DSSCs have become a validated and economically credible competitor to the traditional solid-state junction photovoltaic devices. DSSCs based on biopolymer gel electrolyte systems offer the perspective of competitive conversion efficiencies with a very low-cost fabrication. In this paper, a new starch-based biopolymer gel electrolyte system is prepared by mixing lithium iodide and iodine with bare and citric acid cross-linked potato starches with glycerol as the plasticizing agent. The effect of the preparation methods on the starch cross-linking degree as well as the photoconversion efficiency of the resulting DSSC cells is carefully analyzed. Fourier transform spectroscopy, X-ray diffraction, and scanning electron microscopy were used to characterize the morphology and conformational changes of starch in the electrolytes. The conductivity of the biopolymer electrolytes was determined by electrochemical impedance spectroscopy. DSSC based on the starch-gel polymer electrolytes were characterized by photovoltaic measurements and electrochemical impedance spectroscopy. Results clearly show that the cross-linking increases the recombination resistance and open circuit voltage (VOC of the DSSC, and thereby the photoconversion efficiency of the cell. In particular, electrolytes containing 1.4 g bare and cross-linked starches showed ionic conductivities of σ = 1.61, 0.59, 0.38, and 0.35 S cm−1, and the corresponding DSSCs showed efficiencies of 1.2, 1.4, 0.93, and 1.11%, respectively.

  3. Application of guar gum biopolymer in the prescription of tablets with sodium ibuprofen--quality tests and pharmaceutical availability in vitro.

    Science.gov (United States)

    Berner-Strzelczyk, Aneta; Kołodziejska, Justyna; Zgoda, Marian Mikołaj

    2006-01-01

    The increasing interest of the technology of drug form in natural biopolymers has become the reason for undertaking investigations on the possibility of guar gum application in the prescription of oral solid form of a drug. Alternative compositions and technology of the production of tablets of regulated in time sodium ibuprofen release were worked out for children. Two series of tablets were prepared with guar gum (5 and 10% content) and a series without the biopolymer. The tablet mass in each case contained keryostatic sorbitol and bioadhesive polyvinylpyrrolidone. All tablets were tested as regards the quality of production, compliance with the requirements of Polish Pharmacopoeia VI and potential therapeutic usefulness, manifestation of which is pharmaceutical availability of the therapeutic agent (sodium ibuprofen). The tests demonstrated that the produced tablets with sodium ibuprofen have proper physicochemical properties, in compliance with Polish Pharmacopoeia VI requirements. Application of biopolymer of guar gum type as adjuvant substance contributes to the improvement of the tablet hardness parameters and prevents technological problems (lining mixture of powders to tableting machine punch). The designed tablets demonstrate proper pharmaceutical availability of over 80%. Introduction of guar gum into their prescription prolonged their disintegration time and the rate of sodium ibuprofen release, which predisposes the produced form of a drug to have the function of a tablet with slowed-down release.

  4. Composite biodegradable biopolymer coatings of silk fibroin - Poly(3-hydroxybutyric-acid-co-3-hydroxyvaleric-acid) for biomedical applications

    Science.gov (United States)

    Miroiu, Floralice Marimona; Stefan, Nicolaie; Visan, Anita Ioana; Nita, Cristina; Luculescu, Catalin Romeo; Rasoga, Oana; Socol, Marcela; Zgura, Irina; Cristescu, Rodica; Craciun, Doina; Socol, Gabriel

    2015-11-01

    Composite silk fibroin-poly(3-hydroxybutyric-acid-co-3-hydroxyvaleric-acid) (SF-PHBV) biodegradable coatings were grown by Matrix Assisted Pulsed Laser Evaporation on titanium substrates. Their physico-chemical properties and particularly the degradation behavior in simulated body fluid at 37 °C were studied as first step of applicability in local controlled release for tissue regeneration applications. SF and PHBV, natural biopolymers with excellent biocompatibility, but different biodegradability and tensile strength properties, were combined in a composite to improve their properties as coatings for biomedical uses. FTIR analyses showed the stoichiometric transfer from targets to coatings by the presence in the spectra of the main absorption maxima characteristic of both polymers. XRD investigations confirmed the FTIR results showing differences in crystallization behavior with respect to the SF and PHBV content. Contact angle values obtained through wettability measurements indicated the MAPLE deposited coatings were highly hydrophilic; surfaces turning hydrophobic with the increase of the PHBV component. Degradation assays proved that higher PHBV contents resulted in enhanced resistance and a slower degradation rate of composite coatings in SBF. Distinct drug-release schemes could be obtained by adjusting the SF:PHBV ratio to controllably tuning the coatings degradation rate, from rapid-release formulas, where SF predominates, to prolonged sustained ones, for larger PHBV content.

  5. Inhibition of calcification of bovine pericardium after treatment with biopolymers, E-beam irradiation and in vitro endothelization

    International Nuclear Information System (INIS)

    Polak, Roberta; Rodas, Andrea C.D.; Chicoma, Dennis L.; Giudici, Reinaldo; Beppu, Marisa M.; Higa, Olga Z.; Pitombo, Ronaldo N.M.

    2013-01-01

    This work has investigated the in vitro calcification of bovine pericardium (BP) treated with chitosan (C), silk fibroin (SF) and electron beam irradiation after its endothelization in vitro. For this purpose, freeze-dried BP membranes treated with mixtures of C and SF (1:3, 1:1 and 3:1) and then irradiated by electron beam irradiation were seeded with human umbilical vein endothelial cells (HUVEC) in vitro. After 3 weeks of cultivation these membranes were submitted to in vitro calcification tests using simulated body fluid as the calcifying agent. Control membranes were also studied (without endothelial cells exposure). The results have shown that the membrane compatibility with HUVECs in vitro prevent such biomaterial from calcifying, showing a potential application in biomaterial area, such as cardiac valves and repair patches. - Highlights: ► Bovine pericardium tissue treated with biopolymers followed by electron beam irradiation could be endothelized in vitro ► Calcification was inhibited after endothelization, demonstrating a new anti calcifying treatment for BP membranes ► This membranes could be used as cardiac valves and repair patches.

  6. Preparation and characterization of biopolymers comprising chitosan-grafted-ENR via acid-induced reaction of ENR50 with chitosan

    Directory of Open Access Journals (Sweden)

    M. R. H. Mas Haris

    2014-02-01

    Full Text Available This paper describes the first detailed tailored-approach for the preparation of biopolymers comprising chitosan (CTS grafted onto the backbone of epoxidized natural rubber (CTS-g-ENR. In a typical experiment, appropriate amount of CTS and AlCl3•6H2O was added to a specified amount of ENR50 (ENR with about 50% epoxy content dissolved in a dual-solvent consisting of 1,4-dioxane and water (97.5:2.5% v/v and the resulting mixture refluxed with continuous stirring for 6 hours. Nuclear magnetic resonance (NMR spectral analysis of a biocomposite, CTS-g-ENR-P1, revealed that its epoxy content is 22.36% which is considerably lower than 44.93% as determined for ENR50-control (ENR50 derivative obtained under similar experimental condition but in the absence of CTS. This means that the grafting of CTS onto the backbone of ENR had occurred. The revelation is affirmed by the presence of the characteristic absorption bands of CTS and ENR, and the appearance of new bands at 1219, 902 and 733 cm–1 in the Fourier transform infrared (FTIR spectrum of CTS-g-ENR-P1. Further evidence that CTS had been successfully grafted onto the backbone of ENR can be deduced and described in this paper from the data obtained by means of Differential Scanning Calorimetric analysis, Thermogravimetric analysis and Variable Pressure Scanning Electron Microscopy.

  7. Environment-friendly cathodes using biopolymer chitosan with enhanced electrochemical behavior for use in lithium ion batteries.

    Science.gov (United States)

    Prasanna, K; Subburaj, T; Jo, Yong Nam; Lee, Won Jong; Lee, Chang Woo

    2015-04-22

    The biopolymer chitosan has been investigated as a potential binder for the fabrication of LiFePO4 cathode electrodes in lithium ion batteries. Chitosan is compared to the conventional binder, polyvinylidene fluoride (PVDF). Dispersion of the active material, LiFePO4, and conductive agent, Super P carbon black, is tested using a viscosity analysis. The enhanced structural and morphological properties of chitosan are compared to the PVDF binder using X-ray diffraction analysis (XRD) and field emission scanning electron microscopy (FE-SEM). Using an electrochemical impedance spectroscopy (EIS) analysis, the LiFePO4 electrode with the chitosan binder is observed to have a high ionic conductivity and a smaller increase in charge transfer resistance based on time compared to the LiFePO4 electrode with the PVDF binder. The electrode with the chitosan binder also attains a higher discharge capacity of 159.4 mAh g(-1) with an excellent capacity retention ratio of 98.38% compared to the electrode with the PVDF binder, which had a discharge capacity of 127.9 mAh g(-1) and a capacity retention ratio of 85.13%. Further, the cycling behavior of the chitosan-based electrode is supported by scrutinizing its charge-discharge behavior at specified intervals and by a plot of dQ/dV.

  8. Nano-cellulose biopolymer based nano-biofilm biomaterial using plant biomass: An innovative plant biomaterial dataset

    Directory of Open Access Journals (Sweden)

    A.B.M. Sharif hossain

    2018-04-01

    Full Text Available The nano-cellulose derived nano-biofilm keeps a magnificent role in medical, biomedical, bioengineering and pharmaceutical industries. Plant biomaterial is naturally organic and biodegradable. This study has been highlighted as one of the strategy introducing biomass based nano-bioplastic (nanobiofilm to solve dependency on petroleum and environment pollution because of non-degradable plastic. The data study was carried out to investigate the nano-biopolymer (nanocellulose based nano-biofilm data from corn leaf biomass coming after bioprocess technology without chemicals. Corn leaf biomass was used to produce biodegradable nano-bioplastic for medical and biomedical and other industrial uses. Data on water absorption, odor, pH, cellulose content, shape and firmness, color coating and tensile strength test have been exhibited under standardization of ASTM (American standard for testing and materials. Moreover, the chemical elements of nanobiofilm like K+, CO3−−, Cl−, Na+ showed standard data using the EN (166. Keywords: Nanocellulose, Nanobiofilm, Nanobioplastic, Biodegradable, Corn leaf

  9. Structural and ionic conductivity studies on proton conducting solid biopolymer electrolyte based on 2hydroxyethyl cellulose incorporated DTAB

    Science.gov (United States)

    Ahmad, N. H.; Bakar, N. Y.; Isa, M. I. N.

    2017-09-01

    Solid biopolymer electrolytes (SBEs) based on 2hydroxyethyl cellulose (2HEC) complexes with dodecyltrimethyl ammonium bromide (DTAB) salt in various composition (wt. %) were successfully prepared by using solution casting technique. The ion - polymer interaction and structural studies have been reported by Fourier transform infrared spectroscopy (FTIR) supported with X - ray diffraction (XRD) and Electrical impedance spectroscopy (EIS). FTIR spectral shows interaction of 2HEC with DTAB happen at peak 2914cm-1, 2848cm-1, 2353cm-1, 2328cm-1, 1720cm-1, 1437cm-1, 1344cm-1, 1198cm-1 1095cm-1 1051cm-1, 912cm-1 and 872cm-1. The interaction of complexes leads to an increase in number of ion jump into neighboring vacant sites until it reaches the highest conductivity at room temperature which is 2.80 x 10-5 Scm-1 for sample containing 9wt. % of DTAB. The temperature dependence of the SBEs system exhibits Arrhenius behavior and the XRD spectral analysis shows the higher salt loading the crystallinity of the SBEs which also increased.

  10. Biopolymers/poly(ε-caprolactone)/polyethylenimine functionalized nano-hydroxyapatite hybrid cryogel: Synthesis, characterization and application in gene delivery.

    Science.gov (United States)

    Simionescu, Bogdan C; Drobota, Mioara; Timpu, Daniel; Vasiliu, Tudor; Constantinescu, Cristina Ana; Rebleanu, Daniela; Calin, Manuela; David, Geta

    2017-12-01

    Nano-hydroxyapatite (nHAp), surface functionalized with linear polyethylenimine (LPEI), was used for the preparation of biocomposites in combination with biopolymers and poly(ε-caprolactone) (PCL), by cryogelation technique, to yield biomimetic scaffolds with controlled interconnected macroporosity, mechanical stability, and predictable degradation behavior. The structural characteristics, swelling and degradation behavior of hydroxyapatite and hydroxyapatite/β-tricalcium phosphate (β-TCP) filled matrices were investigated as compared to the corresponding naked polymer 3D system. It was found that the homogeneity and cohesivity of the composite are significantly dependent on the size and amount of the included inorganic particles, which are thus determining the structural parameters. Surface modification with LPEI and nanodimensions favored the nHAp integration in the organic matrix, with preferential location along protein fibers, while β-TCP microparticles induced an increased disorder in the hybrid system. The biocomposite including nHAp only was further investigated targeting biomedical uses, and proved to be non-cytotoxic and capable of acting as gene-activated matrix (GAM). It allowed sustained delivery over time (until 22days) of embedded PEI 25 -pDNA polyplexes at high levels of transgene expression, while insuring a decrease in cytotoxicity as compared to polyplexes alone. Experimental data recommend such biocomposite as an attractive material for regenerative medicine. Copyright © 2017 Elsevier B.V. All rights reserved.

  11. Phase separation in biopolymer gels: a low- to high-solid exploration of structural morphology and functionality.

    Science.gov (United States)

    Kasapis, Stefan

    2008-04-01

    Phase separation in protein and polysaccharide gels remains one of the basic tools of achieving the required structural properties and textural profile in food product formulations. As ever, the industrialist is faced with the challenge of innovation in an increasingly competitive market in terms of ingredient cost, product added-value, and expectations of a healthy life-style to mention but a few. It appears, however, that a gap persists between the fundamental knowledge and a direct application to food related concepts with a growing need for scientific input. Furthermore, within the context of materials science, there is a tendency to examine research findings in either low- or high-solid systems without considering synergistic insights/benefits to contemporary needs, spanning the full range of relevant time-, length-, and concentration scales. This review highlights the latest attempts made to utilize and further develop fundamental protocols from the advanced synthetic polymer research as a source of inspiration for contemporary bio-related applications in low- and intermediate-solid composite gels. Then, it takes advantage of this school of thought to "force a passage" through the phase topology and molecular dynamics of binary biopolymer mixtures at high levels of co-solute. It is hoped that these phenomenological and fundamental tools should be able to bridge the divide in the analysis of the two "types" of composite materials (from low to high solids) thus dealing effectively with the specific and often intricate problems of their science and applications.

  12. Purification and partial elucidation of the structure of an antioxidant carbohydrate biopolymer from the probiotic bacterium Bacillus coagulans RK-02.

    Science.gov (United States)

    Kodali, Vidya P; Perali, Ramu S; Sen, R

    2011-08-26

    An exopolysaccharide (EPS) was isolated from Bacillus coagulans RK-02 and purified by size exclusion chromatography. The purified, homogeneous EPS had an average molecular weight of ∼3 × 10⁴ Da by comparison with FITC-labeled dextran standards. In vivo evaluations showed that, like other reported polysaccharides, this EPS displayed significant antioxidant activity. FTIR spectroscopy analysis showed the presence of hydroxy, carboxy, and α-glycosidic linkages and a mannose residue. GC analysis indicated that the EPS was a heteropolymer composed of glucose, mannose, galactose, glucosamine, and fucose as monomeric constituent units. Partial elucidation of the structure of the carbohydrate biopolymer based on GC-MS and NMR analysis showed the presence of two unique sets of tetrasaccharide repeating units that have 1→3 and 1→6 glycosidic linkages. This is also the first report of a Gram-positive bacterial polysaccharide with both fucose as a sugar monomer and 1→3 and 1→6 glycosidic linkages in the molecular backbone.

  13. Sorption of Lead (Pb from Aqueous Solutions by Sepiolite and Bentonite Modified with Chitosan Biopolymers: Isotherms and Kinetics

    Directory of Open Access Journals (Sweden)

    Hamid Reza Rafiei

    2016-07-01

    Full Text Available In this study, sepiolite and bentonite clay minerals were modified with a natural chitosan biopolymer and the modified-clays were characterized using XRF, XRD, FTIR, SEM, and TOC analyses. The isothermal and kinetic parameters of lead (Pb sorption by both the minerals and the modified-minerals were determined in a batch mode under various conditions such as different contact times and initial concentrations of Pb. It was found that the Freundlich model described well the isotherm experimental data of Pb sorption by the sorbents. Modification with chitosan, however, decreased the Pb adsorption capacity of sepiolite from 83 to 27 mg g-1 and that of bentonite from 56 to 29 mg g-1. Kinetic results showed that more than 24 hours was required for Pb sorption by the natural clays to reach equilibrium, while the equilibrium time reduced to 16 and 4 hours for Pb sorption on chitosan-sepiolite and chitosan–bentonite, respectively. The pseudo-second-order model well described the time-dependent Pb sorption data by sepiolite, chitosan-sepiolite, and chitosan-bentonite, suggesting that chemical sorption is the rate-limiting step of Pb adsorption mechanism. The Pb sorption data by bentonite showed the best fit with Elovich model.

  14. Influence of biopolymers on the solubility of branched-chain amino acids and stability of their solutions.

    Science.gov (United States)

    Hong, Chi Rac; Lee, Gyu Whan; Paik, Hyun-Dong; Chang, Pahn-Shick; Choi, Seung Jun

    2018-01-15

    This study confirmed the possibility of biopolymer-type stabilizers to increase the saturation concentration of branched-chain amino acids by preventing their crystallization/precipitation. Although microfluidization increased the initial solubility, it failed to increase the saturation concentration of the branched-chain amino acids. The saturation concentration of the branched-chain amino acids increased from 3.81% to 4.42% and 4.85% after the incorporation of food hydrocolloids and proteins, respectively. However, the branched-chain amino acids:stabilizer ratio did not affect the solubility. In the case of food hydrocolloid-based solutions, crystal formation and growth of branched-chain amino acids occurred during storage, resulting in the precipitation of branched-chain amino acid crystals. However, food proteins effectively increased the stability of the solubilized branched-chain amino acids. The improved solubility and stability of the solubilized branched-chain amino acids could be attributed to interactions between the functional groups (carboxyl, amine, sulfate, aliphatic, aromatic, etc.) of the stabilizer and the branched-chain amino acid molecules. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Sodium alginate: A promising biopolymer for corrosion protection of API X60 high strength carbon steel in saline medium.

    Science.gov (United States)

    Obot, I B; Onyeachu, Ikenna B; Kumar, A Madhan

    2017-12-15

    Sodium alginate (SA), a polysaccharide biopolymer, has been studied as an effective inhibitor against the corrosion of API X60 steel in neutral 3.5% NaCl using gravimetric and electrochemical techniques (OCP, EIS and EFM). The inhibition efficiency of the SA increased with concentration but was lower at higher temperature (70°C). Electrochemical measurements showed that the SA shifted the steel corrosion potential to more positive value and reduced the kinetics of corrosion by forming an adsorbed layer which mitigated the steel surface wetting, based on contact angle measurement. SEM-EDAX was used to confirm the inhibition of SA on API X60 steel surfaces. The SA adsorbs on the steel surface through a physisorption mechanism using its carboxylate oxygen according to UV-vis and ATR-IR measurements, respectively. This phenomena result in decreased localized pitting corrosion of the API X60 steel in 3.5% NaCl solution. Theoretical results using quantum chemical calculations and Monte Carlo simulations provide further atomic level insights into the interaction of SA with steel surface. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. 25th anniversary article: organic photovoltaic modules and biopolymer supercapacitors for supply of renewable electricity: a perspective from Africa.

    Science.gov (United States)

    Inganäs, Olle; Admassie, Shimelis

    2014-02-12

    The role of materials in civilization is well demonstrated over the centuries and millennia, as materials have come to serve as the classifier of stages of civilization. With the advent of materials science, this relation has become even more pronounced. The pivotal role of advanced materials in industrial economies has not yet been matched by the influence of advanced materials during the transition from agricultural to modern societies. The role of advanced materials in poverty eradication can be very large, in particular if new trajectories of social and economic development become possible. This is the topic of this essay, different in format from the traditional scientific review, as we try to encompass not only two infant technologies of solar energy conversion and storage by means of organic materials, but also the social conditions for introduction of the technologies. The development of organic-based photovoltaic energy conversion has been rapid, and promises to deliver new alternatives to well-established silicon photovoltaics. Our recent development of organic biopolymer composite electrodes opens avenues towards the use of renewable materials in the construction of wooden batteries or supercapacitors for charge storage. Combining these new elements may give different conditions for introduction of energy technology in areas now lacking electrical grids, but having sufficient solar energy inputs. These areas are found close to the equator, and include some of the poorest regions on earth. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Inhibition of calcification of bovine pericardium after treatment with biopolymers, E-beam irradiation and in vitro endothelization

    Energy Technology Data Exchange (ETDEWEB)

    Polak, Roberta [Department of Biochemical and Pharmaceutical Technology, School of Pharmaceutical Sciences, University of Sao Paulo, USP, Sao Paulo, SP (Brazil); Rodas, Andrea C.D. [Biotechnology Center, Energy and Nuclear Research Institute, IPEN-CNEN/SP, Sao Paulo, SP (Brazil); Chicoma, Dennis L.; Giudici, Reinaldo [Department of Chemical Engineering of Polytechnic School, University of Sao Paulo, SP (Brazil); Beppu, Marisa M. [School of Chemical Engineering, University of Campinas, UNICAMP, Campinas, SP (Brazil); Higa, Olga Z. [Biotechnology Center, Energy and Nuclear Research Institute, IPEN-CNEN/SP, Sao Paulo, SP (Brazil); Pitombo, Ronaldo N.M., E-mail: pitombo@usp.br [Department of Biochemical and Pharmaceutical Technology, School of Pharmaceutical Sciences, University of Sao Paulo, USP, Sao Paulo, SP (Brazil)

    2013-01-01

    This work has investigated the in vitro calcification of bovine pericardium (BP) treated with chitosan (C), silk fibroin (SF) and electron beam irradiation after its endothelization in vitro. For this purpose, freeze-dried BP membranes treated with mixtures of C and SF (1:3, 1:1 and 3:1) and then irradiated by electron beam irradiation were seeded with human umbilical vein endothelial cells (HUVEC) in vitro. After 3 weeks of cultivation these membranes were submitted to in vitro calcification tests using simulated body fluid as the calcifying agent. Control membranes were also studied (without endothelial cells exposure). The results have shown that the membrane compatibility with HUVECs in vitro prevent such biomaterial from calcifying, showing a potential application in biomaterial area, such as cardiac valves and repair patches. - Highlights: Black-Right-Pointing-Pointer Bovine pericardium tissue treated with biopolymers followed by electron beam irradiation could be endothelized in vitro Black-Right-Pointing-Pointer Calcification was inhibited after endothelization, demonstrating a new anti calcifying treatment for BP membranes Black-Right-Pointing-Pointer This membranes could be used as cardiac valves and repair patches.

  18. Tumour eradication using synchronous thermal ablation and Hsp90 chemotherapy with protein engineered triblock biopolymer-geldanamycin conjugates.

    Science.gov (United States)

    Chen, Yizhe; Youn, Pilju; Pysher, Theodore J; Scaife, Courtney L; Furgeson, Darin Y

    2014-12-01

    Hepatocellular carcinoma (HCC) suffers high tumour recurrence rate after thermal ablation. Heat shock protein 90 (Hsp90) induced post-ablation is critical for tumour survival and progression. A combination therapy of thermal ablation and polymer conjugated Hsp90 chemotherapy was designed and evaluated for complete tumour eradication of HCC. A thermo-responsive, elastin-like polypeptide (ELP)-based tri-block biopolymer was developed and conjugated with a potent Hsp90 inhibitor, geldanamycin (GA). The anti-cancer efficacy of conjugates was evaluated in HCC cell cultures with and without hyperthermia (43 °C). The conjugates were also administered twice weekly in a murine HCC model as a single treatment or in combination with single electrocautery as the ablation method. ELP-GA conjugates displayed enhanced cytotoxicity in vitro and effective heat shock inhibition under hyperthermia. The conjugates alone significantly slowed the tumour growth without systemic toxicity. Four doses of thermo-responsive ELP-GA conjugates with concomitant simple electrocautery accomplished significant Hsp90 inhibition and sustained tumour suppression. Hsp90 inhibition plays a key role in preventing the recurrence of HCC, and the combination of ablation with targeted therapy holds great potential to improve prognosis and survival of HCC patients.

  19. Design and development of low cost polyurethane biopolymer based on castor oil and glycerol for biomedical applications.

    Science.gov (United States)

    Tan, A C W; Polo-Cambronell, B J; Provaggi, E; Ardila-Suárez, C; Ramirez-Caballero, G E; Baldovino-Medrano, V G; Kalaskar, D M

    2018-02-01

    In the current study, we present the synthesis of novel low cost bio-polyurethane compositions with variable mechanical properties based on castor oil and glycerol for biomedical applications. A detailed investigation of the physicochemical properties of the polymer was carried out by using mechanical testing, ATR-FTIR, and X-ray photoelectron spectroscopy (XPS). Polymers were also tested in short term in-vitro cell culture with human mesenchymal stem cells to evaluate their biocompatibility for potential applications as biomaterial. FTIR analysis confirmed the synthesis of castor oil and glycerol based PU polymers. FTIR also showed that the addition of glycerol as co-polyol increases crosslinking within the polymer backbone hence enhancing the bulk mechanical properties of the polymer. XPS data showed that glycerol incorporation leads to an enrichment of oxidized organic species on the surface of the polymers. Preliminary investigation into in vitro biocompatibility showed that serum protein adsorption can be controlled by varying the glycerol content with polymer backbone. An alamar blue assay looking at the metabolic activity of the cells indicated that castor oil based PU and its variants containing glycerol are non-toxic to the cells. This study opens an avenue for using low cost bio-polyurethane based on castor oil and glycerol for biomedical applications. © 2017 The Authors Biopolymers Published by Wiley Periodicals, Inc.

  20. Biopolymer augmentation of the lag screw in the treatment of femoral neck fractures - a biomechanical in-vitro study

    Directory of Open Access Journals (Sweden)

    Paech A

    2010-04-01

    Full Text Available Abstract The cut-out of the sliding screw is one of the most common complications in the treatment of intertrochanteric fractures. The reasons for the cut-out are: a suboptimal position of the hip-screw in the femoral head, the type of fracture and poor bone quality. The aim of this study was to reproduce the cut-out event biomechanically and to evaluate the possible prevention of this event by the use of a biopolymer augmentation of the hip screw. Concerning the density and compression force of osteoporotic femoral bone polyurethane foam according to the terms of the Association for Standard Testing Material (ASTMF 1839-97 was used as test material. The polyurethane foam Lumoltan 200 with a compression force of 3.3 Mpa and a density of 0.192 g/cm3 was used to reproduce the osteoporotic bone of the femoral fragment (density 12 lbm/ft3. A cylinder of 50 mm of length and 50 mm of width was produced by a rotary splint raising procedure with planar contact. The axial load of the system was performed by a hydraulic force cylinder of a universal test machine type Zwick 1455, Ulm, Germany. The CCD-angle of the used TGN-System was preset at 130 degrees. The migration pattern of the hip screw in the polyurethane foam was measured and expressed as a curve of the distance in millimeter [mm] against the applied load in Newton [N] up to the cut-out point. During the tests the implants reached a critical changing point from stable to unstable with an increased load progression of steps of 50 Newton. This unstable point was characterized by an increased migration speed in millimeters and higher descending gradient in the migration curve. This peak of the migration curve served as an indicator for the change of the hip screw position in the simulated bone material. The applied load in the non-augmented implant showed that in this group for a density degree of 12 (0,192 g/cm3 the mean force at the failure point was 1431 Newton (± 52 Newton. In the augmented

  1. Structural, mechanical and electrical properties biopolymer blend nanocomposites derived from poly (vinyl alcohol)/cashew gum/magnetite

    Science.gov (United States)

    Ramesan, M. T.; Jayakrishnan, P.; Manojkumar, T. K.; Mathew, G.

    2018-01-01

    Blending of poly vinyl alcohol (PVA) and natural biopolymers such as cashew gum (CG) with magnetite (Fe3O4) nanoparticles has been a promising way for preparing bio-degradable polymeric blend nanocomposites. PVA/CG/Fe3O4 blend nanocomposites have been prepared by a simple solution casting technique using water as the green solvent. The characterization of blend nanocomposites has been carried out by using Fourier transform infrared, UV, x-ray diffraction (XRD), high resolution transmission electron microscopy, scanning electron microscopy (SEM), differential scanning calorimetry, thermogravimetric analysis, mechanical properties and electrical conductivity. The interaction between nanoparticles and the blend segments was confirmed from the shift in characteristic absorption peaks of nanocomposites compared to PVA/CG blend. XRD analysis has shown the presence of crystalline peaks of nanoparticles in the blend matrix. The uniform distribution of Fe3O4 nanoparticles in the blend was revealed by TEM and SEM. The strong interaction of nanoparticles with the blend has been confirmed by the increase in glass transition temperature resulting from the reduced flexibility of the blend nanocomposite compared to that of the blend system. An increase in thermal stability and tensile strength and reduction in elongation at break of nanocomposites have been noticed with the increasing loading of nanoparticles. The AC electrical conductivity, dielectric constant and dielectric loss of the nanocomposites have been found to be higher than that of the blend. Generally, it can be stated that the magnetite nanoparticles acts as a potential filler in the PVA/CG blend at 7 wt% loading, giving the best balance of properties.

  2. Inorganic nanoparticles for the spatial and temporal control of organic reactions: Applications to radical degradation of biopolymer networks

    Science.gov (United States)

    Walker, Joan Marie

    Nanoparticles of gold and iron oxide not only possess remarkable optical and magnetic properties, respectively, but are also capable of influencing their local environment with an astounding degree of precision. Using nanoparticles to direct the reactivity of organic molecules near their surface provides a unique method of spatial and temporal control. Enediynes represent an exceptional class of compounds that are thermally reactive to produce a diradical intermediate via Bergman cycloaromatization. While natural product enediynes are famously cytotoxic, a rich chemistry of synthetic enediynes has developed utilizing creative means to control this reactivity through structure, electronics, metal chelation, and external triggering mechanisms. In a heretofore unexplored arena for Bergman cyclization, we have investigated the reactivity of enediynes in connection with inorganic nanoparticles in which the physical properties of the nanomaterial are directly excited to thermally promote aromatization. As the first example of this methodology, gold nanoparticles conjugated with (Z)-octa-4-en-2,6-diyne-1,8-dithiol were excited with 514 nm laser irradiation. The formation of aromatic and polymeric products was confirmed through Raman spectroscopy and electron microscopy. Water soluble analogues Au-PEG-EDDA and Fe3O4-PEG-EDDA (EDDA = (Z)-octa-4-en-2,6-diyne-1,8-diamine) show similar reactivity under laser irradiation or alternating magnetic field excitation, respectively. Furthermore, we have used these functionalized nanoparticles to attack proteinaceous substrates including fibrin and extracellular matrix proteins, capitalizing on the ability of diradicals to disrupt peptidic bonds. By delivering a locally high payload of reactive molecules and thermal energy to the large biopolymer, network restructuring and collapse is achieved. As a synthetic extension towards multifunctional nanoparticles, noble metal seed-decorated iron oxides have also been prepared and assessed for

  3. Application of an amine functionalized biopolymer in the colonic delivery of glycyrrhizin: a design and in vivo efficacy study.

    Science.gov (United States)

    Kumar De, Amit; Datta, Sriparna; Mukherjee, Arup

    2013-01-01

    In our current study, a newer amine functionalized guar gum derivative was studied for its efficacy in colonic drug delivery. Glycyrrhizic acid mono-ammonium salt was used as the model drug. Drug-loaded microparticles were formulated by ionic crosslinking using sodium tripolyphosphate. The Scanning Electron Microscopic study revealed spherical particles of sizes from 4.9 ± 3.8 μm to 6.9 ± 3.9 μm. The FT-IR studies presented a possible interaction between the drug and the polymer. The drug was encapsulated in amorphous form as observed from the powder X-Ray Diffraction studies. A cumulative drug release study was carried out in simulated gastric, intestinal, and colonic fluids. The cumulative drug release studies presented a burst release followed by a sustained release of the drug in simulated colonic fluid containing rat cecal contents. The drug-polymer ratio was optimised using a 3(2) factorial design by taking the amounts of glycyrrhizic acid (X1) and guar gum alkyl amine (X2) as the independant variables. The percent cumulative drug release at 240 mins (Q240), 720 mins (Q720), and at 1,440 mins (Q1440) were considered as the dependant variables. The efficacy of the optimized formulation was studied in a 2,4,6-trinitrobenzene sulfonic acid-induced rat colitis model. The tissue's nitric oxide, malondialdehyde, and myeloperoxidase activities were found to be much lower in the microparticle-treated group compared to free drug-treated group. The histology of the colonic tissue from the treated group of animals revealed almost no infiltration of inflammatory cells in the tissue for the microparticle-treated group of animals. The synthesized amine derivative of guar gum was found to be better in vitro with a better in vivo efficacy in the colonic delivery of glycyrrhizic acid monoammonium salt and can be considered as a newer modified biopolymer for colonic drug delivery.

  4. Adsorption of nitrate from aqueous solution by magnetic amine-crosslinked biopolymer based corn stalk and its chemical regeneration property

    Energy Technology Data Exchange (ETDEWEB)

    Song, Wen [Key Laboratory of Water Pollution Control and Recycling (Shandong), School of Environmental Science and Engineering, Shandong University, Jinan 250100 (China); Gao, Baoyu, E-mail: bygao@sdu.edu.cn [Key Laboratory of Water Pollution Control and Recycling (Shandong), School of Environmental Science and Engineering, Shandong University, Jinan 250100 (China); Xu, Xing; Wang, Fang; Xue, Nan; Sun, Shenglei [Key Laboratory of Water Pollution Control and Recycling (Shandong), School of Environmental Science and Engineering, Shandong University, Jinan 250100 (China); Song, Wuchang; Jia, Ruibao [Jinan Water and Wastewater Monitoring Center, 250033 Jinan (China)

    2016-03-05

    Graphical abstract: Scheme of mechanism for HCl and NaCl regeneration of MAB-CS. - Highlights: • Magnetic amine-crosslinked bio-adsorbent was prepared for nitrate uptake. • The characters of adsorbent were determined by VSM, TGA, XRD, SEM, TEM, FT-IR and XPS. • This novel bio-adsorbent could achieve rapid separation from effluents. • Chemical regeneration of the saturated magnetic bio-adsorbent was conducted. • The adsorption followed the pseudo second order model and Langmuir model. - Abstract: A novel adsorbent of magnetic amine-crosslinked biopolymer based corn stalk (MAB-CS) was synthesized and used for nitrate removal from aqueous solution. The characters and adsorption mechanisms of this bio-adsorbent were determined by using VSM, TGA, XRD, SEM, TEM, FT-IR and XPS, respectively. The results revealed that the saturated magnetization of MAB-CS reached 6.25 emu/g. Meanwhile, the studies of various factors indicated that this novel magnetic bio-adsorbent performed well over a considerable wide pH range of 6.0∼9.0, and the presence of PO{sub 4}{sup 3−} and SO{sub 4}{sup 2−} would markedly decrease the nitrate removal efficiency. Furthermore, the nitrate adsorption by MAB-CS perfectly fitted the Langmuir isotherm model (R{sup 2} = 0.997–0.999) and pseudo second order kinetic model (R{sup 2} = 0.953–0.995). The calculated nitrate adsorption capacity of MAB-CS was 102.04 mg/g at 318 K by Langmuir model, and thermodynamic study showed that nitrate adsorption is an spontaneous endothermic process. The regeneration experiments indicated its merit of regeneration and stability with the recovery efficient of 118∼147%. By integrating the experimental results, it was found that the removal of nitrate was mainly via electrostatic attraction and ion exchange. And this novel bio-adsorbent prepared in this work could achieve effective removal of nitrate and rapid separation from effluents simultaneously.

  5. A fluorescence-based method for direct measurement of submicrosecond intramolecular contact formation in biopolymers: an exploratory study with polypeptides.

    Science.gov (United States)

    Hudgins, Robert R; Huang, Fang; Gramlich, Gabriela; Nau, Werner M

    2002-01-30

    A fluorescent amino acid derivative (Fmoc-DBO) has been synthesized, which contains 2,3-diazabicyclo[2.2.2]oct-2-ene (DBO) as a small, hydrophilic fluorophore with an extremely long fluorescence lifetime (325 ns in H2O and 505 ns in D2O under air). Polypeptides containing both the DBO residue and an efficient fluorescence quencher allow the measurement of rate constants for intramolecular end-to-end contact formation. Bimolecular quenching experiments indicated that Trp, Cys, Met, and Tyr are efficient quenchers of DBO (k(q) = 20, 5.1, 4.5, and 3.6 x 10(8) M(-1) x s(-1) in D2O), while the other amino acids are inefficient. The quenching by Trp, which was selected as an intrinsic quencher, is presumed to involve exciplex-induced deactivation. Flexible, structureless polypeptides, Trp-(Gly-Ser)n-DBO-NH2, were prepared by standard solid-phase synthesis, and the rates of contact formation were measured through the intramolecular fluorescence quenching of DBO by Trp with time-correlated single-photon counting, laser flash photolysis, and steady-state fluorometry. Rate constants of 4.1, 6.8, 4.9, 3.1, 2.0, and 1.1 x 10(7) s(-1) for n = 0, 1, 2, 4, 6, and 10 were obtained. Noteworthy was the relatively slow quenching for the shortest peptide (n = 0). The kinetic data are in agreement with recent transient absorption studies of triplet probes for related peptides, but the rate constants are significantly larger. In contrast to the flexible structureless Gly-Ser polypeptides, the polyproline Trp-Pro4-DBO-NH2 showed insignificant fluorescence quenching, suggesting that a high polypeptide flexibility and the possibility of probe-quencher contact is essential to induce quenching. Advantages of the new fluorescence-based method for measuring contact formation rates in biopolymers include high accuracy, fast time range (100 ps-1 micros), and the possibility to perform measurements in water under air.

  6. Incorporation of zinc oxide to dispersions of biopolymers and release of the metallic ion in vitro; Incorporacao de oxido de zinco a dispersoes de biopolimeros e liberacao do ion metalico in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Barreto, Marina S.R.; Ferreira, Willian H.; Andrade, Cristina T., E-mail: marinarodriguesbarreto@gmail.com [Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, RJ (Brazil)

    2015-07-01

    Zinc oxide (ZnO) nanoparticles, obtained from a commercial product, were dispersed in different biopolymers, to be added to piglet feeds. The resulting products, prepared with sodium alginate (SA), chitosan (CH) and low methoxyl pectin (LMP) were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The release of Zn{sup 2+} was investigated under simulated conditions of the gastrointestinal tract of piglets, and analyzed by atomic absorption spectroscopy (AA). The results showed that the structural factors, which have influence on the biopolymer/ZnO interactions, govern the behavior of Zn{sup 2+} release. (author)

  7. Ant-cave structured MnCO3/Mn3O4 microcubes by biopolymer-assisted facile synthesis for high-performance pseudocapacitors

    Science.gov (United States)

    Chandra Sekhar, S.; Nagaraju, Goli; Yu, Jae Su

    2018-03-01

    Porous and ant-cave structured MnCO3/Mn3O4 microcubes (MCs) were facilely synthesized via a biopolymer-assisted hydrothermal approach. Herein, chitosan was used as a natural biopolymer, which greatly controls the surface morphology and size of the prepared composite. The amino and hydroxyl group-functionalized chitosan engraves the outer surface of MCs during the hydrothermal process, which designs the interesting morphology of nanopath ways on the surface of MCs. When used as an electrode material for pseudocapacitors, the ant-cave structured MnCO3/Mn3O4 MCs showed superior energy storage values compared to the material prepared without chitosan in aqueous electrolyte solution. Precisely, the prepared ant-cave structured MnCO3/Mn3O4 MCs exhibited a maximum specific capacitance of 116.2 F/g at a current density of 0.7 A/g with an excellent cycling stability of 73.86% after 2000 cycles. Such facile and low-cost synthesis of pseudocapacitive materials with porous nanopaths is favorable for the fabrication of high-performance energy storage devices.

  8. Preparation of the polyelectrolyte complex hydrogel of biopolymers via a semi-dissolution acidification sol-gel transition method and its application in solid-state supercapacitors

    Science.gov (United States)

    Zhao, Jian; Chen, Yu; Yao, Ying; Tong, Zong-Rui; Li, Pu-Wang; Yang, Zi-Ming; Jin, Shao-Hua

    2018-02-01

    Hydrogels have drawn many attentions as the solid-state electrolytes in flexible solid-state supercapacitors (SCs) recently. Among them, the polyelectrolyte complex hydrogel (PECH) electrolytes of natural polymers are more competitive because of their environmentally friendly property and low cost. However, while mixing two biopolymer solutions with opposite charges, the strong electrostatic interactions between the cationic and anionic biopolymers may result in precipitates instead of hydrogels. Here we report a novel method, semi-dissolution acidification sol-gel transition (SD-A-SGT), for the preparation of the PECH of chitosan (CTS) and sodium alginate (SA), with the controllable sol-gel transition and uniform composition and successfully apply it as the hydrogel electrolyte of solid-state supercapacitors (SCs). The CTS-SA PECH exhibits an extremely high ionic conductivity of 0.051 S·cm-1 and reasonable mechanical properties with a tensile strength of 0.29 MPa and elongation at break of 109.5%. The solid-state SC fabricated with the CTS-SA PECH and conventional polyaniline (PANI) nanowire electrodes provided a high specific capacitance of 234.6 F·g-1 at 5 mV·s-1 and exhibited excellent cycling stability with 95.3% capacitance retention after 1000 cycles. Our work may pave a novel avenue to the preparation of biodegradable PECHs of full natural polymers, and promote the development of environmentally friendly electronic devices.

  9. FY 2000 report on the results of the regional consortium R and D project - Regional consortium energy. First year report. Development of a next generation biopolymer information measuring system based on the nano channel electrophoresis; 2000 nendo chiiki consortium kenkyu kaihatsu jigyo - chiiki consortium energy. Nano channel denki eido ni motozuku jisedai seitai kobunshi joho keisoku system no kaihatsu (dai 1 nendo) seika hokokusho

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-03-01

    On the basis of the nano channel electrophoresis technology, the construction was proceeded with of a system which integrates the basic process such as reaction, separation and detection needed for measuring biopolymer information and analyzes a number of samples simultaneously and with high accuracy/high sensitivity. Studies were made in the following three fields: 1) development of the basement technology on extraction/amplification/separation/detection of biopolymer; 2) development of micro-processing technology and system design and study on the development of device; 3) comprehensive investigational study. In 1), developmental technology is divided into the following: technology to effectively fraction/refine biopolymer from biological samples, technology for recognition control and manipulation of biopolymer, technology of amplification use micro-reaction of biopolymer, multiple selection technology of biopolymer using the specific molecular recognition, and technology for ultra-high speed separation of biopolymer. As to the multiple selection technology, DNA terminal recognizing hemin is altered by thiol group and connected to the surface of electrode to make an electrode type hemin recognition device. (NEDO)

  10. Chemical characterization of Xanthan biopolymers synthesized by Xanthomonas campestris pv pruni strains; Caracterizacao quimica de biopolimeros sintetizados por Xanthomonas campestris pv pruni

    Energy Technology Data Exchange (ETDEWEB)

    Moreira, Angelita da S.; Vendruscolo, Claire T.; Furlan, Ligia [Universidade Federal de Pelotas, RS (Brazil). Centro de Biotecnologia]. E-mail: angelita@ufpel.tche.br; claire@ufpel.tche.br; ligia@ufpel.tche.br; Galland, Griselda [Rio Grande do Sul Univ., Porto Alegre, RS (Brazil). Inst. de Qumica

    2001-07-01

    In this work we describe the characterisation of Xanthan biopolymers synthesized by two Xanthomonas campestris pv pruni strains, in aerobic fermentation. By chromatography on TLC we could notice the presence of Mannose monomer in higher proportion in the 82 strain with relation to the another ones. The viscosity results showed the temperature dependence. The 06 and 82 strains had their viscosity increased whereas for the 87 strain we could observe a reduction with temperature increasing. The {sup 13}C NMR spectrum of 87 strain showed the characteristic signals at approximately 92.8, 70.4 and 61.4 ppm, attributed to C1, C4 and C6 from glucose monomer, with higher intensity. (author)

  11. Combining asymmetrical flow field-flow fractionation with light-scattering and inductively coupled plasma mass spectrometric detection for characterization of nanoclay used in biopolymer nanocomposites

    DEFF Research Database (Denmark)

    Schmidt, Bjørn; Petersen, Jens Højslev; Koch, C. Bender

    2009-01-01

    mechanical and barrier properties and be more suitable for a wider range of food-packaging applications. Natural or synthetic clay nanofillers are being investigated for this purpose in a project called NanoPack funded by the Danish Strategic Research Council. In order to detect and characterize the size...... of clay nanoparticulates, an analytical system combining asymmetrical flow field-flow fractionation (AF4) with multi-angle light-scattering detection (MALS) and inductively coupled plasma mass spectrometry (ICP-MS) is presented. In a migration study, we tested a biopolymer nanocomposite consisting...... of polylactide (PLA) with 5% Cloisite®30B (a derivatized montmorillonite clay) as a filler. Based on AF4-MALS analyses, we found that particles ranging from 50 to 800 nm in radius indeed migrated into the 95% ethanol used as a food simulant. The full hyphenated AF4-MALS-ICP-MS system showed, however, that none...

  12. Time domain NMR and conductivity study of apple pectin biopolymers; Estudo por RMN no dominio do tempo e condutividade em filmes biopolimericos de pectina de maca

    Energy Technology Data Exchange (ETDEWEB)

    Mattos, Ritamara I.; Souto, Sergio; Tambelli, Caio E., E-mail: cristal_br@yahoo.com.br [Universidade de sao Paulo (USP), Pirassununga, SP (Brazil). Faculdade de Zootecnia e Engenharia de Alimentos

    2015-07-01

    This communication presents results of {sup 1}H nuclear magnetic resonance of continuous distributions of spin-spin relaxation time (T{sub 2}) and A.C. conductivity of apple pectin biopolymers plasticized with glycerol and containing acetic acid. The continuous distributions reveals up to three components of spin-spin relaxation times (T{sub 2}). The two short T{sub 2} components were associated with protons of pectin polymer chain and the longer T{sub 2} can be attributed with the protons of the glycerol. The conductivity values increase with glycerol concentration with maximum at 7.9 x 10{sup -4} S cm{sup -1} for sample with 3.0 g of glycerol at 83 deg C. The behavior of activation energy and T{sub 2} continuous distribution indicate an increase of proton mobility due the structural changes caused by glycerol addition. (author)

  13. Time domain NMR and conductivity study of apple pectin biopolymers; Estudo por RMN no dominio do tempo e condutividade em filmes biopolimericos de pectina de maca

    Energy Technology Data Exchange (ETDEWEB)

    Mattos, Ritamara; Souto, Sergio; Tambelli, Caio E., E-mail: cristal_br@yahoo.com.br [Universidade de Sao Paulo (USP), Pirassununga, SP (Brazil). Faculdade de Zootecnia e Engenharia de Alimentos

    2013-07-01

    This communication presents results of {sup 1}H nuclear magnetic resonance of continuous distributions of spin-spin relaxation time (T{sub 2}) and A.C. conductivity of apple pectin biopolymers plasticised with glycerol and containing acetic acid. The continuous distributions reveals up to three components of spin-spin relaxation times (T{sub 2}). The two short T{sub 2} components were associated with protons of pectin polymer chain and the longer T{sub 2} can be attributed with the protons of the glycerol. The conductivity values increase with glycerol concentration with maximum at 7.9 x 10{sup -4} S cm{sup -1} for sample with 3.0 g of glycerol at 83 deg C. The behavior of activation energy and T{sub 2} continuous distribution indicate an increase of proton mobility due the structural changes caused by glycerol addition. (author)

  14. Interactive association between biopolymers and biofunctions in carinata seeds as energy feedstock and their coproducts (carinata meal) from biofuel and bio-oil processing before and after biodegradation: current advanced molecular spectroscopic investigations.

    Science.gov (United States)

    Yu, Peiqiang; Xin, Hangshu; Ban, Yajing; Zhang, Xuewei

    2014-05-07

    Recent advances in biofuel and bio-oil processing technology require huge supplies of energy feedstocks for processing. Very recently, new carinata seeds have been developed as energy feedstocks for biofuel and bio-oil production. The processing results in a large amount of coproducts, which are carinata meal. To date, there is no systematic study on interactive association between biopolymers and biofunctions in carinata seed as energy feedstocks for biofuel and bioethanol processing and their processing coproducts (carinata meal). Molecular spectroscopy with synchrotron and globar sources is a rapid and noninvasive analytical technique and is able to investigate molecular structure conformation in relation to biopolymer functions and bioavailability. However, to date, these techniques are seldom used in biofuel and bioethanol processing in other research laboratories. This paper aims to provide research progress and updates with molecular spectroscopy on the energy feedstock (carinata seed) and coproducts (carinata meal) from biofuel and bioethanol processing and show how to use these molecular techniques to study the interactive association between biopolymers and biofunctions in the energy feedstocks and their coproducts (carinata meal) from biofuel and bio-oil processing before and after biodegradation.

  15. Effective adsorption of oil droplets from oil-in-water emulsion using metal ions encapsulated biopolymers: Role of metal ions and their mechanism in oil removal.

    Science.gov (United States)

    Elanchezhiyan, S Sd; Prabhu, Subbaiah Muthu; Meenakshi, Sankaran

    2018-06-01

    Herein, synthesized and compared the three different kinds of hybrid bio-polymeric composites viz., lanthanum embedded chitosan/gelatin (La@CS-GEL), zirconium embedded chitosan/gelatin (Zr@CS-GEL) and cerium embedded chitosan/gelatin (Ce@CS-GEL) in terms of their oil uptake efficiency. The adsorption efficiency was studied under various optimized parameters like contact time, pH, dose, initial oil concentration and temperature. The oil adsorption capacity was found to be 91, 82 and 45% for La@CS-GEL, Zr@CS-GEL and Ce@CS-GEL composites respectively. The metals were used as a bridging material to connect both CS and GEL using the hydrophilic groups to enhance the oil recovery by hydrophobic interaction. Also, the introduction of metal ions on the surface of biopolymers would modify the oil/water properties which in turn, decrease the interfacial tension between oil and water phases. The mechanism of oil uptake was explained using Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), thermogravimetric analysis (TGA), scanning electron microscope (SEM), energy dispersive X-ray (EDAX) and heat of combustion. The experimental data confirmed Langmuir isotherm as the best fit for oil adsorption process. Thermodynamic parameters such as standard free energy (ΔG°), standard enthalpy (ΔH°) and standard entropy (ΔS°) indicated that the oil adsorption was spontaneous and endothermic. The oil adsorption mechanism was established based on isotherm and thermodynamic models. Copyright © 2018 Elsevier B.V. All rights reserved.

  16. Study on the effects of wheat bran incorporation on water mobility and biopolymer behavior during bread making and storage using time-domain 1H NMR relaxometry.

    Science.gov (United States)

    Hemdane, S; Jacobs, P J; Bosmans, G M; Verspreet, J; Delcour, J A; Courtin, C M

    2017-12-01

    Water binding is suggested to be key in the deleterious effect of wheat bran on bread quality. This study investigates water mobility and biopolymer behavior during bran-rich bread making and storage, using 1 H NMR. Coarse, ground, and pericarp-enriched bran were incorporated in bread dough, and their impact on freshly baked and stored bread properties was assessed. Compared to wheat flour control dough, bran incorporation resulted in a progressive immobilization of water during dough resting, which could be linked to changes in evolution of dough height during fermentation and oven rise. This, together with modified starch gelatinization behavior upon baking, can be related with the inferior quality of bran-rich breads. The impact was most pronounced with pericarp-enriched bran. Textural quality during storage was less affected for coarse or ground bran-rich bread compared to wheat flour bread, which could be principally attributed to retardation of amylopectin retrogradation in the presence of bran. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. A Biopolymer Heparin Sodium Interlayer Anchoring TiO2 and MAPbI3 Enhances Trap Passivation and Device Stability in Perovskite Solar Cells.

    Science.gov (United States)

    You, Shuai; Wang, Hui; Bi, Shiqing; Zhou, Jiyu; Qin, Liang; Qiu, Xiaohui; Zhao, Zhiqiang; Xu, Yun; Zhang, Yuan; Shi, Xinghua; Zhou, Huiqiong; Tang, Zhiyong

    2018-04-18

    Traps in the photoactive layer or interface can critically influence photovoltaic device characteristics and stabilities. Here, traps passivation and retardation on device degradation for methylammonium lead trihalide (MAPbI 3 ) perovskite solar cells enabled by a biopolymer heparin sodium (HS) interfacial layer is investigated. The incorporated HS boosts the power conversion efficiency from 17.2 to 20.1% with suppressed hysteresis and Shockley-Read-Hall recombination, which originates primarily from the passivation of traps near the interface between the perovskites and the TiO 2 cathode. The incorporation of an HS interfacial layer also leads to a considerable retardation of device degradation, by which 85% of the initial performance is maintained after 70 d storage in ambient environment. Aided by density functional theory calculations, it is found that the passivation of MAPbI 3 and TiO 2 surfaces by HS occurs through the interactions of the functional groups (COO - , SO 3 - , or Na + ) in HS with undersaturated Pb and I ions in MAPbI 3 and Ti 4+ in TiO 2 . This work demonstrates a highly viable and facile interface strategy using biomaterials to afford high-performance and stable perovskite solar cells. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Layer-by-Layer films based on biopolymers extracted from red seaweeds and polyaniline for applications in electrochemical sensors of chromium VI

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira Farias, Emanuel Airton de; Corrêa dos Santos, Marianne; Araujo Dionísio, Natália de; Quelemes, Patrick V.; Souza Almeida Leite, José Roberto de [Núcleo de Pesquisa em Biodiversidade e Biotecnologia, BIOTEC, CMRV, UFPI, Parnaíba, PI 64202-020 (Brazil); Eaton, Peter [UCIBIO, REQUIMTE, Departamento de Química e Bioquímica, Faculdade de Ciências, Universidade do Porto, 4169-007 Porto (Portugal); Alves da Silva, Durcilene [Núcleo de Pesquisa em Biodiversidade e Biotecnologia, BIOTEC, CMRV, UFPI, Parnaíba, PI 64202-020 (Brazil); Eiras, Carla, E-mail: eiras@cnpq.br [Núcleo de Pesquisa em Biodiversidade e Biotecnologia, BIOTEC, CMRV, UFPI, Parnaíba, PI 64202-020 (Brazil); Laboratório Interdisciplinar de Materiais Avançados, LIMAV, CCN, UFPI, Teresina, PI 64049-550 (Brazil)

    2015-10-15

    Graphical abstract: - Highlights: • LbL films based on PANI and polysaccharides of seaweeds were produced and applied sensors of Cr (VI). - Abstract: This paper proposes a new application for natural polysaccharides (agar and carrageenan), both extracted from the cell wall of red seaweeds. Thin films were prepared by the Layer-by-Layer (LbL) self-assembly technique onto ITO (tin-doped indium oxide), where the polysaccharides of interest were deposited in layers alternating with polyaniline (PANI). The films developed were characterized by cyclic voltammetry (CV), ultraviolet–visible spectroscopy (UV–vis) and atomic force microscopy (AFM). Results showed the presence of agar as well as carrageenan, which improves the electrochemical stability of the conducting polymer in an acid medium. The interactions at the molecular level between PANI and the biopolymers affected the most appropriate sequence of deposition as employed in the process of material immobilization and also influenced the resulting morphology. Among the films studied, the most promising system as regards electrochemical measurements was the ITO/agar/PANI system, which was subsequently employed in the electrochemical detection of chromium (VI)

  19. Layer-by-Layer films based on biopolymers extracted from red seaweeds and polyaniline for applications in electrochemical sensors of chromium VI

    International Nuclear Information System (INIS)

    Oliveira Farias, Emanuel Airton de; Corrêa dos Santos, Marianne; Araujo Dionísio, Natália de; Quelemes, Patrick V.; Souza Almeida Leite, José Roberto de; Eaton, Peter; Alves da Silva, Durcilene; Eiras, Carla

    2015-01-01

    Graphical abstract: - Highlights: • LbL films based on PANI and polysaccharides of seaweeds were produced and applied sensors of Cr (VI). - Abstract: This paper proposes a new application for natural polysaccharides (agar and carrageenan), both extracted from the cell wall of red seaweeds. Thin films were prepared by the Layer-by-Layer (LbL) self-assembly technique onto ITO (tin-doped indium oxide), where the polysaccharides of interest were deposited in layers alternating with polyaniline (PANI). The films developed were characterized by cyclic voltammetry (CV), ultraviolet–visible spectroscopy (UV–vis) and atomic force microscopy (AFM). Results showed the presence of agar as well as carrageenan, which improves the electrochemical stability of the conducting polymer in an acid medium. The interactions at the molecular level between PANI and the biopolymers affected the most appropriate sequence of deposition as employed in the process of material immobilization and also influenced the resulting morphology. Among the films studied, the most promising system as regards electrochemical measurements was the ITO/agar/PANI system, which was subsequently employed in the electrochemical detection of chromium (VI)

  20. Rheometric Non-Isothermal Gelatinization Kinetics of Chickpea Flour-Based Gluten-Free Muffin Batters with Added Biopolymers

    Directory of Open Access Journals (Sweden)

    María Dolores Alvarez

    2017-01-01

    Full Text Available An attempt was made to analyze the elastic modulus (G0 of chickpea flour (CF-based muffin batters made with CF alone and with added biopolymers (whey protein (WP, xanthan gum (XG, inulin (INL, and their blends in order to evaluate their suitability to be a wheat flour (WF substitute in muffins, and to model the heat-induced gelatinization of batters under non-isothermal heating condition from 25 ◦C to 90 ◦C. A rheological approach is proposed to determine the kinetic parameters (reaction order (n, frequency factor (k0, and activation energy (Ea using linearly-increasing temperature. Zero-order reaction kinetics adequately described batter gelatinization process, therefore assuming a constant rate independent of the initial G0 value. The change of the derivative of G0 with respect to time (dG0/dt versus temperature is described by one exponential function with activation energies ranging from 118 to 180 kJ·mol−1. Control wheat gluten batter, with higher and lower starch and protein contents, respectively, than CF-based batters, exhibited the highest Ea value. Formulation of CF-based gluten-free batters with starch and protein contents closer to the levels of WF-based batter could be a strategy to decrease differences in kinetic parameters of muffin batters and, therefore, in technological characteristics of baked muffins.

  1. Serish inulin and wheat biopolymers interactions in model systems as a basis for understanding the impact of inulin on bread properties: a FTIR investigation.

    Science.gov (United States)

    Pourfarzad, Amir; Habibi Najafi, Mohammad B; Haddad Khodaparast, Mohammad H; Khayyat, Mohammad Hassanzadeh

    2015-12-01

    In this study the interactions between Serish root inulin and the main biopolymer types of wheat flour namely gluten, starch and phospholipid, were investigated in different model systems using Fourier transform infrared (FTIR) spectroscopy to unravel the underlying physical mechanism by which inulin impacts dough and bread properties. Interactions of inulin with starch and phospholipid were not considerable compared to gluten, but it was also clear that the modes of these interactions varied with the type and the amount of additives used in model formulation. This study revealed that when inulin is added to gluten, water redistribution promotes partial dehydration of gluten and collapse of β-spirals into intermolecular β-sheet structures; this trans-conformations might be due to physical reasons are believed to further impact the poor quality of bread containing added inulin. Upon performing Gaussian-Lorenzian curve fitting, it was observed that by adding of inulin to model systems, the relative contribution of characteristic peaks of β-turn and intramolecular β-sheet was progressively decreased whereas intermolecular β-sheet and α-helix contents were increased.

  2. Effect of plasticization on the conductivity and dielectric properties of starch-chitosan blend biopolymer electrolytes infused with NH4Br

    Science.gov (United States)

    Shukur, M. F.; Majid, N. A.; Ithnin, R.; Kadir, M. F. Z.

    2013-11-01

    The present work examines the effect of plasticization on the conductivity and dielectric properties of starch-chitosan blend biopolymer electrolytes. Initial Fourier transform infrared (FTIR) spectroscopy analysis of the hydroxyl band recorded 3280 cm-1 for starch and 3354 cm-1 for chitosan. The FTIR spectrum of starch-chitosan blend films shows that the hydroxyl band shifted to 3288 cm-1, indicating interaction between pure starch and chitosan. Different concentrations of ammonium bromide (NH4Br) were then added to the blend solution and stirred until complete dissolution. The homogeneous solutions were then placed onto different plastic Petri dishes, where they were left to dry. The highest conductivity value of (9.72 ± 0.95) × 10-5 S cm-1 was obtained with addition of 35 wt% NH4Br. Addition of 30 wt% ethylene carbonate increased the conductivity value to (1.44 ± 0.51) × 10-3 S cm-1. The plots of dielectric constant, ɛr, against frequency for both plasticized and unplasticized systems show non-Debye behaviour. The temperature dependence of the power law exponent for the highest conducting sample in the unplasticized system follows the small polaron hopping model while the conduction mechanism of the highest conducting sample in the plasticized system can be represented by the quantum mechanical tunnelling model.

  3. A versatile method for combining different biopolymers in a core/shell fashion by 3D plotting to achieve mechanically robust constructs.

    Science.gov (United States)

    Akkineni, Ashwini Rahul; Ahlfeld, Tilman; Lode, Anja; Gelinsky, Michael

    2016-10-07

    Three-dimensional extrusion of two different biomaterials in a core/shell (c/s) fashion has gained much interest in the last couple of years as it allows for fabricating constructs with novel and interesting properties. We now demonstrate that combining high concentrated (16.7 wt%) alginate hydrogels as shell material with low concentrated, soft biopolymer hydrogels as core leads to mechanically stable and robust 3D scaffolds. Alginate, chitosan, gellan gum, gelatin and collagen hydrogels were utilized successfully as core materials-hydrogels which are too soft for 3D plotting of open-porous structures without an additional mechanical support. The respective c/s scaffolds were characterized concerning their morphology, mechanical properties and swelling behavior. It could be shown that core as well as shell part can be loaded with growth factors and that the release depends on core composition and shell thickness. Neither the plotting process nor the crosslinking with 1M CaCl 2 denatured the proteins. When core and shell were loaded with different growth factors (VEGF and BMP-2, respectively) a dual release was achieved. Finally, live human endothelial cells were integrated in the core material, demonstrating that this new strategy can be used for bioprinting purposes as well.

  4. Design of a hybrid biomaterial for tissue engineering: Biopolymer-scaffold integrated with an autologous hydrogel carrying mesenchymal stem-cells.

    Science.gov (United States)

    Weinstein-Oppenheimer, Caroline R; Brown, Donald I; Coloma, Rodrigo; Morales, Patricio; Reyna-Jeldes, Mauricio; Díaz, María J; Sánchez, Elizabeth; Acevedo, Cristian A

    2017-10-01

    Biologically active biomaterials as biopolymers and hydrogels have been used in medical applications providing favorable results in tissue engineering. In this research, a wound dressing device was designed by integration of an autologous clot hydrogel carrying mesenchymal stem-cells onto a biopolymeric scaffold. This hybrid biomaterial was tested in-vitro and in-vivo, and used in a human clinical case. The biopolymeric scaffold was made with gelatin, chitosan and hyaluronic acid, using a freeze-drying method. The scaffold was a porous material which was designed evaluating both physical properties (glass transition, melting temperature and pore size) and biological properties (cell viability and fibronectin expression). Two types of chitosan (120 and 300kDa) were used to manufacture the scaffold, being the high molecular weight the most biologically active and stable after sterilization with gamma irradiation (25kGy). A clot hydrogel was formulated with autologous plasma and calcium chloride, using an approach based on design of experiments. The optimum hydrogel was used to incorporate cells onto the porous scaffold, forming a wound dressing biomaterial. The wound dressing device was firstly tested in-vitro using human cells, and then, its biosecurity was evaluated in-vivo using a rabbit model. The in-vitro results showed high cell viability after one week (99.5%), high mitotic index (19.8%) and high fibronectin expression. The in-vivo application to rabbits showed adequate biodegradability capacity (between 1 and 2weeks), and the histological evaluation confirmed absence of rejection signs and reepithelization on the wound zone. Finally, the wound dressing biomaterial was used in a single human case to implant autologous cells on a skin surgery. The medical examination indicated high biocompatibility, partial biodegradation at one week, early regeneration capacity at 4weeks and absence of rejection signs. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. The genome sequence of the commercially cultivated mushroom Agrocybe aegerita reveals a conserved repertoire of fruiting-related genes and a versatile suite of biopolymer-degrading enzymes.

    Science.gov (United States)

    Gupta, Deepak K; Rühl, Martin; Mishra, Bagdevi; Kleofas, Vanessa; Hofrichter, Martin; Herzog, Robert; Pecyna, Marek J; Sharma, Rahul; Kellner, Harald; Hennicke, Florian; Thines, Marco

    2018-01-15

    Agrocybe aegerita is an agaricomycete fungus with typical mushroom features, which is commercially cultivated for its culinary use. In nature, it is a saprotrophic or facultative pathogenic fungus causing a white-rot of hardwood in forests of warm and mild climate. The ease of cultivation and fructification on solidified media as well as its archetypal mushroom fruit body morphology render A. aegerita a well-suited model for investigating mushroom developmental biology. Here, the genome of the species is reported and analysed with respect to carbohydrate active genes and genes known to play a role during fruit body formation. In terms of fruit body development, our analyses revealed a conserved repertoire of fruiting-related genes, which corresponds well to the archetypal fruit body morphology of this mushroom. For some genes involved in fruit body formation, paralogisation was observed, but not all fruit body maturation-associated genes known from other agaricomycetes seem to be conserved in the genome sequence of A. aegerita. In terms of lytic enzymes, our analyses suggest a versatile arsenal of biopolymer-degrading enzymes that likely account for the flexible life style of this species. Regarding the amount of genes encoding CAZymes relevant for lignin degradation, A. aegerita shows more similarity to white-rot fungi than to litter decomposers, including 18 genes coding for unspecific peroxygenases and three dye-decolourising peroxidase genes expanding its lignocellulolytic machinery. The genome resource will be useful for developing strategies towards genetic manipulation of A. aegerita, which will subsequently allow functional genetics approaches to elucidate fundamentals of fruiting and vegetative growth including lignocellulolysis.

  6. Effective adsorption of hexavalent chromium through a three center (3c) co-operative interaction with an ionic liquid and biopolymer

    International Nuclear Information System (INIS)

    Santhana Krishna Kumar, A.; Gupta, Timsi; Kakan, Shruti Singh; Kalidhasan, S.; Manasi,; Rajesh, Vidya; Rajesh, N.

    2012-01-01

    Highlights: ► Tetraoctylammoniumbromide impregnated chitosan was prepared by ultrasonication. ► Physico-chemical characterization of the adsorbent was studied in detail. ► The sorbent has an adsorption capacity of 63.69 mg g −1 for chromium(VI). ► The mechanism involves a three center interaction with positive co-operative effect. ► Adsorbent is effectively regenerated with ammonium hydroxide. - Abstract: Biopolymers as well as ionic liquids are known for their potential applications. In this work, we report the utility of chitosan as an excellent platform for impregnating the ionic liquid, tetraoctylammonium bromide by ultrasonication and its subsequent adsorption for chromium(VI). The effective mass transfer due to sonication coupled with the hydrogen bonding interaction between chitosan-ionic liquid and the electrostatic interaction involving the amino groups in chitosan and hexavalent chromium governs this three center (3c) co-operative mechanism. The adsorption followed a pseudo second order kinetics with a Langmuir adsorption capacity of 63.69 mg g −1 . Various isotherm models were used to correlate the experimental data and the adsorption process is exothermic with a decreased randomness at the solid–solution interface. The thermodynamics of the spontaneous adsorption process could be explained through a positive co-operative effect between the host (chitosan) and the guest (ionic liquid). The adsorbed chromium(VI) could be converted to ammonium chromate using ammonium hydroxide, thereby regenerating the adsorbent. The method could be translated into action in the form of practical application to a real sample containing chromium.

  7. Effect of plasticization on the conductivity and dielectric properties of starch–chitosan blend biopolymer electrolytes infused with NH4Br

    International Nuclear Information System (INIS)

    Shukur, M F; Majid, N A; Ithnin, R; Kadir, M F Z

    2013-01-01

    The present work examines the effect of plasticization on the conductivity and dielectric properties of starch–chitosan blend biopolymer electrolytes. Initial Fourier transform infrared (FTIR) spectroscopy analysis of the hydroxyl band recorded 3280 cm −1 for starch and 3354 cm −1 for chitosan. The FTIR spectrum of starch–chitosan blend films shows that the hydroxyl band shifted to 3288 cm −1 , indicating interaction between pure starch and chitosan. Different concentrations of ammonium bromide (NH 4 Br) were then added to the blend solution and stirred until complete dissolution. The homogeneous solutions were then placed onto different plastic Petri dishes, where they were left to dry. The highest conductivity value of (9.72 ± 0.95) × 10 −5  S cm −1 was obtained with addition of 35 wt% NH 4 Br. Addition of 30 wt% ethylene carbonate increased the conductivity value to (1.44 ± 0.51) × 10 −3  S cm −1 . The plots of dielectric constant, ε r , against frequency for both plasticized and unplasticized systems show non-Debye behaviour. The temperature dependence of the power law exponent for the highest conducting sample in the unplasticized system follows the small polaron hopping model while the conduction mechanism of the highest conducting sample in the plasticized system can be represented by the quantum mechanical tunnelling model. (paper)

  8. Comparative study on the effects of negatively-charged biopolymers on chitosan-based gels for the development of instantaneous gels

    International Nuclear Information System (INIS)

    Jimeno, Austin Ed B.; Chakraborty, Soma

    2015-01-01

    Polymeric electrolytic complexes are solutions of charged/ionized chains. These solutions of positive and negative charge can be combined to make instantaneous networks bonded by electrostatic interactions, a gel network. These electrostatic interaction allows for easy application in injectable gels as the network can be temporarily distributed with the application of force and reformed on the relief of it. Possible applications for these injectable gels include drug delivery and wound-healing. κ-Carrageenan, dextran sulfate, alginate, and chitosan are polyelectrolytic biocompatible polymers which are widely studied and used for a variety of biomedical applications. Gel networks are made by combining a negatively-charged (κ-Carrageenan, dextran sulfate, or alginate) and positively charged (chitosan) solutions. The strong electrostatic interaction between the opposite charges from the gel network and the inherent biocompatibility of the polymers allow future biomedical applications. Quat 188-modified chitosan has additional sites for electrostatic bonding, can be dissolved in neutral, basic, and acidic pH, and has shown inherent antibacterial activity. The objectives of this study are the following: to formulate chitosan-based gels mixing solutions of chitosan with solutions of either κ-Carrageenan, dextran sulfate, or alginate, study the gelation of the gels as function of time and pH (4, 7, and 9) using UV-Vis, characterize the chitosan-based gels through DSC and DMA, characterize the physiological degradation of the chitosan-based gels, and compare results with those from Quat 188-modified chitosan-based gels. Polyelectrolytic solutions of chitosan and negatively-charged biopolymer of similar viscosities were mixed. It was determined from the UV-Vis spectroscopy of the chitosan-carrageenan gels under pH7 buffer that the increase of concentration by a factor of 5 for 0.006M-0.0095M and 1.25 for 0.0095M-0.0150M Chitosan-Carrageenan gels improved gelation by the

  9. Biopolymer Processing Using Ionic Liquids

    Science.gov (United States)

    2014-08-07

    polymerization. Chitin is not only the main component of the shells of crustaceans, but also exists as a structural polysaccharide of insects, mushrooms...combination of the dissolution of the biomass with the acid catlaysts to depolymerize the biomass into feedstock type chemicals. By using an imidazolium...Technical Section Technical Objective Ionic liquids have demonstrated the ability to effectively dissolve biomass ,1,2 including chitin and

  10. Interfacial behaviour of biopolymer multilayers

    NARCIS (Netherlands)

    Corstens, Meinou N.; Osorio Caltenco, Lilia A.; Vries, de Renko; Schroën, Karin; Berton-Carabin, Claire C.

    2017-01-01

    Although multilayered emulsions have been related to reduced lipolysis, the involved interfacial phenomena have never been studied directly. In this work, we systematically built multilayers of whey protein and pectin, which we further subjected to digestive conditions, using two different

  11. Polymers and biopolymers at interfaces

    Science.gov (United States)

    Hall, A. R.; Geoghegan, M.

    2018-03-01

    This review updates recent progress in the understanding of the behaviour of polymers at surfaces and interfaces, highlighting examples in the areas of wetting, dewetting, crystallization, and ‘smart’ materials. Recent developments in analysis tools have yielded a large increase in the study of biological systems, and some of these will also be discussed, focussing on areas where surfaces are important. These areas include molecular binding events and protein adsorption as well as the mapping of the surfaces of cells. Important techniques commonly used for the analysis of surfaces and interfaces are discussed separately to aid the understanding of their application.

  12. Biotechnological opportunities to biopolymers production

    International Nuclear Information System (INIS)

    Ballesteros, M.; Ballesteros, I.; Oliva, J.M.

    1994-01-01

    The increasing garbage mountain is more and more recognized as an ecological threat, Space for landfills is limited and additional Incineration capacities require high capital investments and pose additional environmental problems. This paper discusses the current development and utilization state of new biodegradable polymers. Special attention is focused on microbiological production of poli-D-Beta-hydroxybutyrate acid (PHB), reviewing the metabolic regulation of PHB and the elements to determine its industrial scale production. (Author) 6 refs

  13. An environmentally benign route for the development of compressible, thermally insulating and fire retardant aerogels through self-assembling the silk fibroin biopolymer inside the silica structure - An approach towards 3D printing of aerogels.

    Science.gov (United States)

    Maleki, Hajar; Montes, Susan; Hayati-Roodbari, Nastaran; Putz, Florian; Huesing, Nicola

    2018-06-04

    Thanks to the exceptional materials properties of silica aerogels, this fascinating highly porous material has found high performance and real-life applications in various modern industries. However, a requirement for a broadening of these applications is based on the further improvement of their properties especially with regard to mechanical strength and post-synthesis processability with minimum compromise to the other physical properties. Here, we report an entirely novel, simple and aqueous based synthesis approach to prepare mechanically robust aerogel hybrids by co-gelation of silk fibroin (SF) biopolymer, extracted from silkworm cocoons. The synthesis is based on a one-step sequential processes of acid catalysis (physical) crosslinking of the SF biopolymer and simultaneous polycondensation of tetramethyl orthosilicate (TMOS), in the presence of 5-(trimethoxysilyl)pentanoic acid (TMSPA) as a coupling agent and subsequent solvent exchange and supercritical drying. Extensive characterizations by solid-state 1H-NMR, 29Si-NMR, and 2D 1H-29Si heteronuclear correlation (HETCOR) MAS NMR spectroscopy as well as various microscopic techniques (SEM, TEM) and mechanical assessment, confirmed the molecular-level homogeneity of the hybrid nanostructure. The developed silica-SF aerogel hybrids contained an improved set of material properties, such as low density (ρb, average = 0.11 - 0.2 g cm-3), high porosity (~90%), high specific surface area (~ 400-800 m2 g-1), excellent flexibility in compression (up to 80% of strain) with three-order of magnitude improvement in the Young's modulus over that of pristine silica aerogels. In addition, the silica-SF hybrid aerogels are fire retardant and demonstrated excellent thermal insulation performance with thermal conductivities (λ) of (0.033-0.039 Wm-1 K-1). As a further advantage, the formulated hybrid silica-SF aerogel showed an excellent printability in the wet state using a micro-extrusion based 3D printing approach. The

  14. The thermo-mechano-chemical twin-screw reactor, a new perspective for the biorefinery of sunflower whole plant: aqueous extraction of oil and other biopolymers, and production of biodegradable fiberboards from cake

    Directory of Open Access Journals (Sweden)

    Evon Philippe

    2016-09-01

    Full Text Available Biorefinery of sunflower whole plant was performed successfully using a thermo-mechano-chemical twin-screw reactor. This led to the aqueous extraction of oil and other biopolymers like proteins, pectins and non pectic sugars. It resulted in the overall fractionation of biomass, thus allowing a complete valorization of the input. This biorefinery process was not only efficient but it was also environment-friendly. In addition, it contributed to the production of different end products for various industrial applications. Firstly, the hydrophilic phase will be recycled to the process. Secondly, the densest oil-in-water emulsion is a promising candidate for the formulation of cosmetic creams. Thirdly, the upper hydrophobic phase will be usable for the waterproofing treatment of the surface of agromaterials by coating. Its demixing will also lead to the production of proteins with tensioactive properties. These will serve for the food industry. Lastly, the cake was a mixture of plasticized proteins and lignocellulosic fibers. It was thus considered as a natural composite. Its molding into cohesive fiberboards was conducted successfully using both thermopressing and compression molding processes. The self-bonded boards with high density will be suitable for use as load bearing boards in dry conditions (floor underlayers, interior partitions, furniture, etc.. Positioned in walls and ceilings, boards with medium and low density will contribute to the heat insulation of buildings. In addition, the bulk cake will be also usable as a loose fill insulation material. As proposed, this flow chart thus allows a valorization for all fractions originating from the twin-screw reactor.

  15. Combining vibrational biomolecular spectroscopy with chemometric techniques for the study of response and sensitivity of molecular structures/functional groups mainly related to lipid biopolymer to various processing applications.

    Science.gov (United States)

    Yu, Gloria Qingyu; Yu, Peiqiang

    2015-09-01

    The objectives of this project were to (1) combine vibrational spectroscopy with chemometric multivariate techniques to determine the effect of processing applications on molecular structural changes of lipid biopolymer that mainly related to functional groups in green- and yellow-type Crop Development Centre (CDC) pea varieties [CDC strike (green-type) vs. CDC meadow (yellow-type)] that occurred during various processing applications; (2) relatively quantify the effect of processing applications on the antisymmetric CH3 ("CH3as") and CH2 ("CH2as") (ca. 2960 and 2923 cm(-1), respectively), symmetric CH3 ("CH3s") and CH2 ("CH2s") (ca. 2873 and 2954 cm(-1), respectively) functional groups and carbonyl C=O ester (ca. 1745 cm(-1)) spectral intensities as well as their ratios of antisymmetric CH3 to antisymmetric CH2 (ratio of CH3as to CH2as), ratios of symmetric CH3 to symmetric CH2 (ratio of CH3s to CH2s), and ratios of carbonyl C=O ester peak area to total CH peak area (ratio of C=O ester to CH); and (3) illustrate non-invasive techniques to detect the sensitivity of individual molecular functional group to the various processing applications in the recently developed different types of pea varieties. The hypothesis of this research was that processing applications modified the molecular structure profiles in the processed products as opposed to original unprocessed pea seeds. The results showed that the different processing methods had different impacts on lipid molecular functional groups. Different lipid functional groups had different sensitivity to various heat processing applications. These changes were detected by advanced molecular spectroscopy with chemometric techniques which may be highly related to lipid utilization and availability. The multivariate molecular spectral analyses, cluster analysis, and principal component analysis of original spectra (without spectral parameterization) are unable to fully distinguish the structural differences in the

  16. Biopolymers for Sample Collection, Protection, and Preservation

    Science.gov (United States)

    2015-05-19

    knowledge of sample collection from various matrices is crucial. Recovery and preservation of microorganisms prior to analysis are important...Another method for encapsulating bacteria for use in biodegradation of gasoline involves a complex process using gellan gum (Moslemy et al. 2002). Many...use of acacia gum in preserving microorganisms for extended periods of time without refrigeration (Krumnow et al. 2009; Sorokulova et al. 2008, 2012

  17. New projectiles: multicharged metal clusters and biopolymers

    International Nuclear Information System (INIS)

    Della-Negra, S.; Gardes, D.; Le Beyec, Y.; Waast, B.

    1991-01-01

    Metal clusters and molecules are the one mean to realize simultaneous impacts of several atoms on a reduced surface(∼100A). The interaction characteristics is the non-linearity of energy deposition; the perturbation that the cluster produces, is above than the sum of the perturbation induced by its components, taken separately. The purpose of ORION project is to accelerate these new projectiles at ORSAY Tandem. The considered mass range is from 100 Daltons to 100 000 Daltons and energy range from MeV to GeV

  18. PC12 polarity on biopolymer nanogratings

    International Nuclear Information System (INIS)

    Cecchini, M; Ferrari, A; Beltram, F

    2008-01-01

    Cell differentiation properties are strongly entangled with the morphology and physical properties of the extracellular environment. A complete understanding of this interaction needs artificial scaffolds with controlled nano-/micro-topography. We induced specific topographies by nanoimprint lithography (NIL) on tissue culture polystyrene (TCPS) dishes substrates and, using light microscopy and high-magnification scanning-electron-microscopy, quantitatively compared the changes in PC12 differentiation phenotype induced by the periodicity of the nanopatterns. This analysis revealed that nanogratings reduce the number of neurites produced by PC12 cells upon treatment with NGF and that neuronal bipolarity correlated with an increased stretching of the cell body and a reduced length of the cell neuronal protrusions

  19. Tension-induced binding of semiflexible biopolymers

    International Nuclear Information System (INIS)

    Benetatos, Panayotis; Heydt, Alice von der; Zippelius, Annette

    2014-01-01

    We investigate theoretically the effect of polymer tension on the collective behavior of reversibly binding cross-links. For this purpose, we employ a model of two weakly bending wormlike chains aligned in parallel by a tensile force, with a sequence of inter-chain binding sites regularly spaced along the contours. Reversible cross-links attach and detach at the sites with an affinity controlled by a chemical potential. In a mean-field approach, we calculate the free energy of the system and find the emergence of a free-energy barrier which controls the reversible (un)binding. The tension affects the conformational entropy of the chains which competes with the binding energy of the cross-links. This competition gives rise to a sudden increase in the fraction of bound sites as the tension increases. We show that this transition is related to the cross-over between weak and strong localization of a directed polymer in a pinning potential. The cross-over to the strongly bound state can be interpreted as a mechanism for force-stiffening which exceeds the capabilities of single-chain elasticity and thus available only to reversibly cross-linked polymers. (paper)

  20. Cytocompatibility of Plasma and Thermally Treated Biopolymers

    Directory of Open Access Journals (Sweden)

    Petr Slepička

    2013-01-01

    Full Text Available This paper is focused on the surface characterization of plasma and consequently thermally treated biocompatible polymers. PLLA (poly(L-lactide acid and PMP (poly-4-methyl-1-pentene are studied. The influence of Ar plasma treatment on the surface polarity of substrate measured immediately after treatment and during the polymer surface aging is studied. Surface roughness, morphology, wettability, and surface chemistry were determined. Plasma treatment leads to significant changes in PLLA surface morphology and chemistry, with the PMP being slightly affected. The higher resistance to plasma fluence results in smaller ablation of PMP than that of PLLA. The plasma treatment improves cell adhesion and proliferation on the PMP. Plasma treatment of PLLA influences mostly the homogeneity of adhered and proliferated VSMC.

  1. Mechanical response of biopolymer double networks

    Science.gov (United States)

    Carroll, Joshua; Das, Moumita

    We investigate a double network model of articular cartilage (AC) and characterize its equilibrium mechanical response. AC has very few cells and the extracellular matrix mainly determines its mechanical response. This matrix can be thought of as a double polymer network made of collagen and aggrecan. The collagen fibers are stiff and resist tension and compression forces, while aggrecans are flexible and control swelling and hydration. We construct a microscopic model made of two interconnected disordered polymer networks, with fiber elasticity chosen to qualitatively mimic the experimental system. We study the collective mechanical response of this double network as a function of the concentration and stiffness of the individual components as well as the strength of the connection between them using rigidity percolation theory. Our results may provide a better understanding of mechanisms underlying the mechanical resilience of AC, and more broadly may also lead to new perspectives on the mechanical response of multicomponent soft materials. This work was partially supported by a Cottrell College Science Award.

  2. Viability of Biopolymers for Enhanced Oil Recovery

    NARCIS (Netherlands)

    Sveistrup, Marte; van Mastrigt, Frank; Norrman, Jens; Picchioni, Francesco; Paso, Kristofer

    2016-01-01

    Xanthan gum and scleroglucan are assessed as environmentally friendly enhanced oil recovery (EOR) agents. Viscometric and interfacial tension measurements show that the polysaccharides exhibit favorable viscosifying performance, robust shear tolerance, electrolyte tolerance, and moderate

  3. Tension-induced binding of semiflexible biopolymers

    Science.gov (United States)

    Benetatos, Panayotis; von der Heydt, Alice; Zippelius, Annette

    2015-03-01

    We investigate theoretically the effect of polymer tension on the collective behaviour of reversible cross-links. We use a model of two parallel-aligned, weakly-bending wormlike chains with a regularly spaced sequence of binding sites subjected to a tensile force. Reversible cross-links attach and detach at the binding sites with an affinity controlled by a chemical potential. In a mean-field approach, we calculate the free energy of the system and we show the emergence of a free energy barrier which controls the reversible (un)binding. The tension affects the conformational entropy of the chains which competes with the binding energy of the cross-links. This competition gives rise to a sudden increase in the fraction of bound sites as the polymer tension increases. The force-induced first-order transition in the number of cross-links implies a sudden force-induced stiffening of the effective stretching modulus of the polymers. This mechanism may be relevant to the formation and stress-induced strengthening of stress fibers in the cytoskeleton. We acknowledge support by the Deutsche Forschungsgemeinschaft (DFG) via grant SFB-937/A1.

  4. Chitosan: A potential biopolymer for wound management.

    Science.gov (United States)

    Bano, Ijaz; Arshad, Muhammad; Yasin, Tariq; Ghauri, Muhammad Afzal; Younus, Muhammad

    2017-09-01

    It has been seen that slow healing and non-healing wounds conditions are treatable but still challenging to humans. Wound dressing usually seeks for biocompatible and biodegradable recipe. Natural polysaccharides like chitosan have been examined for its antimicrobial and healing properties on the basis of its variation in molecular weight and degree of deacetylation. Chitosan adopts some vital characteristics for treatment of various kinds of wounds which include its bonding nature, antifungal, bactericidal and permeability to oxygen. Chitosan therefore has been modified into various forms for the treatment of wounds and burns. The purpose of this review article is to understand the exploitation of chitosan and its derivatives as wound dressings. This article will also provide a concise insight on the properties of chitosan necessary for skin healing and regeneration, particularly highlighting the emerging role of chitosan films as next generation skin substitutes for the treatment of full thickness wounds. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. Use of Biopolymers in Antimicrobial Food Packaging

    Science.gov (United States)

    Recent outbreaks of foodborne illness and food recalls continue to push for innovative ways to inhibit microbial growth in foods. As an additional hurdle to food processes, antimicrobial food packaging can play an important role in reducing the risk of pathogen contamination of processed foods. In...

  6. Biopolymer nanocomposite films reinforced with nanocellulose whiskers

    Science.gov (United States)

    Amit Saxena; Marcus Foston; Mohamad Kassaee; Thomas J. Elder; Arthur J. Ragauskas

    2011-01-01

    A xylan nanocomposite film with improved strength and barrier properties was prepared by a solution casting using nanocellulose whiskers as a reinforcing agent. The 13C cross-polarization magic angle spinning (CP/MAS) nuclear magnetic resonance (NMR) analysis of the spectral data obtained for the NCW/xylan nanocomposite films indicated the signal intensity originating...

  7. Functionalization of magnetic nanowires by charged biopolymers

    DEFF Research Database (Denmark)

    Magnin, D.; Callegari, V.; Mátéfi-Tempfli, Stefan

    2008-01-01

    We report on a facile method for the preparation of biocompatible and bioactive magnetic nanowires. The method consists of the direct deposition of polysaccharides by layer-by-layer (LbL) assembly onto a brush of metallic nanowires; obtained by electrodeposition of the metal within the nanopores ...

  8. Um novo substituto vascular: arterioplastia femoral em cães com remendo de membrana de biopolímero de cana-de-açúcar - avaliação hemodinâmica e histopatológica A new vascular substitute: femoral artery angioplasty in dogs using sugarcane biopolymer membrane patch - hemodynamic and histopathologic evaluation

    Directory of Open Access Journals (Sweden)

    Silvio Romero de Barros Marques

    2007-12-01

    érias femorais com os remendos foram retirados para estudo histopatológico e os animais foram mortos com dose tóxica de anestésico. RESULTADOS: No período de avaliação de 180 dias, nos dois grupos, não foram observados casos de infecção da ferida operatória, dilatação, ruptura, falso-aneurisma ou trombose. Nos dois grupos foi encontrada, na superfície externa dos remendos, uma resposta inflamatória crônica com neutrófilos e linfócitos além de fibrose. Na superfície interna dos remendos, em ambos os grupos, foi encontrada fibrose. No grupo controle ocorreu invasão dos remendos de e-PTFE por fibroblastos. CONCLUSÕES: Com base nos resultados obtidos com o modelo experimental utilizado, durante o período de observação de 180 dias, conclui-se que a membrana do biopolímero de cana-de-açúcar constitui-se em um substituto arterial adequado quando utilizado sob forma de remendos em artérias femorais de cães.BACKGROUND: Achievement of an ideal arterial substitute to be used in the reconstruction of small- and medium-caliber arteries is still the main objective of most scientific research studies developed in the area of vascular substitutes. Sugarcane biopolymer membrane could be extremely useful to perform vascular reconstruction in arteries with diameter smaller than 4 mm, allowing treatment of diseases that affect millions of people in Brazil and worldwide. OBJECTIVE: To evaluate the hemodynamic and histopathologic behavior of sugarcane biopolymer membrane when used as a patch in femoral artery angioplasty in dogs. METHOD: Eight adult mongrel dogs, under general anesthesia, underwent percutaneous Doppler velocimetry of the left and right femoral arteries for preoperative control at the Health Sciences Center Experimental Research Laboratory of Universidade Federal de Pernambuco. After being disinfected, the dogs underwent femoral artery patch angioplasty using a sugarcane membrane biopolymer patch on the left side and an expanded PTFE (e-PTFE patch on the

  9. Recombinant Spider Silks—Biopolymers with Potential for Future Applications

    Directory of Open Access Journals (Sweden)

    Thomas Scheibel

    2011-03-01

    Full Text Available Nature has evolved a range of materials that compete with man-made materials in physical properties; one of these is spider silk. Silk is a fibrous material that exhibits extremely high strength and toughness with regard to its low density. In this review we discuss the molecular structure of spider silk and how this understanding has allowed the development of recombinant silk proteins that mimic the properties of natural spider silks. Additionally, we will explore the material morphologies and the applications of these proteins. Finally, we will look at attempts to combine the silk structure with chemical polymers and how the structure of silk has inspired the engineering of novel polymers.

  10. Structure-function-property-design interplay in biopolymers: spider silk.

    Science.gov (United States)

    Tokareva, Olena; Jacobsen, Matthew; Buehler, Markus; Wong, Joyce; Kaplan, David L

    2014-04-01

    Spider silks have been a focus of research for almost two decades due to their outstanding mechanical and biophysical properties. Recent advances in genetic engineering have led to the synthesis of recombinant spider silks, thus helping to unravel a fundamental understanding of structure-function-property relationships. The relationships between molecular composition, secondary structures and mechanical properties found in different types of spider silks are described, along with a discussion of artificial spinning of these proteins and their bioapplications, including the role of silks in biomineralization and fabrication of biomaterials with controlled properties. Copyright © 2013 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  11. Native Silk Feedstock as a Model Biopolymer: A Rheological Perspective.

    Science.gov (United States)

    Laity, Peter R; Holland, Chris

    2016-08-08

    Variability in silk's rheology is often regarded as an impediment to understanding or successfully copying the natural spinning process. We have previously reported such variability in unspun native silk extracted straight from the gland of the domesticated silkworm Bombyx mori and discounted classical explanations such as differences in molecular weight and concentration. We now report that variability in oscillatory measurements can be reduced onto a simple master-curve through normalizing with respect to the crossover. This remarkable result suggests that differences between silk feedstocks are rheologically simple and not as complex as originally thought. By comparison, solutions of poly(ethylene-oxide) and hydroxypropyl-methyl-cellulose showed similar normalization behavior; however, the resulting curves were broader than for silk, suggesting greater polydispersity in the (semi)synthetic materials. Thus, we conclude Nature may in fact produce polymer feedstocks that are more consistent than typical man-made counterparts as a model for future rheological investigations.

  12. Nuclear Magnetic Resonance (NMR) Spectroscopic Characterization of Nanomaterials and Biopolymers

    Science.gov (United States)

    Guo, Chengchen

    Nanomaterials have attracted considerable attention in recent research due to their wide applications in various fields such as material science, physical science, electrical engineering, and biomedical engineering. Researchers have developed many methods for synthesizing different types of nanostructures and have further applied them in various applications. However, in many cases, a molecular level understanding of nanoparticles and their associated surface chemistry is lacking investigation. Understanding the surface chemistry of nanomaterials is of great significance for obtaining a better understanding of the properties and functions of the nanomaterials. Nuclear magnetic resonance (NMR) spectroscopy can provide a familiar means of looking at the molecular structure of molecules bound to surfaces of nanomaterials as well as a method to determine the size of nanoparticles in solution. Here, a combination of NMR spectroscopic techniques including one- and two-dimensional NMR spectroscopies was used to investigate the surface chemistry and physical properties of some common nanomaterials, including for example, thiol-protected gold nanostructures and biomolecule-capped silica nanoparticles. Silk is a natural protein fiber that features unique properties such as excellent mechanical properties, biocompatibility, and non-linear optical properties. These appealing physical properties originate from the silk structure, and therefore, the structural analysis of silk is of great importance for revealing the mystery of these impressive properties and developing novel silk-based biomaterials as well. Here, solid-state NMR spectroscopy was used to elucidate the secondary structure of silk proteins in N. clavipes spider dragline silk and B. mori silkworm silk. It is found that the Gly-Gly-X (X=Leu, Tyr, Gln) motif in spider dragline silk is not in a beta-sheet or alpha-helix structure and is very likely to be present in a disordered structure with evidence for 31-helix confirmation. In addition, the conformations of the Ala, Ser, and Tyr residues in silk fibroin of B. mori were investigated and it indicates that the Ala, Ser, and Tyr residues are all present in disordered structures in silk I (before spinning), while show different conformations in silk II (after spinning). Specifically, in silk II, the Ala and Tyr residues are present in both disordered structures and beta-sheet structures, and the Ser residues are present primarily in beta-sheet structures.

  13. Dataset on the physical characterization of biopolymer coated magnetic nanoparticles

    Directory of Open Access Journals (Sweden)

    Shazia Bano

    2016-12-01

    Full Text Available The data presented in this article is related to the research article entitled “Paclitaxel loaded magnetic nanocomposites with folate modified chitosan/carboxymethyl surface; a vehicle for imaging and targeted drug delivery” (S. Bano, M. Afzal, M.M. Waraich, K. Alamgir, S. Nazir, 2016 [1]. It contains the absorbance spectra, band gap energies of pure nickel-ferrite nano cores (NFs, and calibration curve of Paclitaxel. Thermal stability analysis of pure NFs, chitosan (CS and carboxymethyl cellulose (CMC-conjugated NFs samples is also included in the data.

  14. Novel Biopolymers Based on an Expanded Genetic Alphabet

    Science.gov (United States)

    1999-02-18

    by anion-exchange HPLC with an Alltech Associates column (Macrosphere 300A WAx, 7 um, 4.6 x 250 mm), using either of the two gradients with A = 25...energetic advantage of the correct hydrogen-bonding partner, contributing to the specificity of correct nucleotide incorporation opposite 1 in the template

  15. Electro-Fermentation in Aid of Bioenergy and Biopolymers

    Directory of Open Access Journals (Sweden)

    Prasun Kumar

    2018-02-01

    Full Text Available The soaring levels of industrialization and rapid progress towards urbanization across the world have elevated the demand for energy besides generating a massive amount of waste. The latter is responsible for poisoning the ecosystem in an exponential manner, owing to the hazardous and toxic chemicals released by them. In the past few decades, there has been a paradigm shift from “waste to wealth”, keeping the value of high organic content available in the wastes of biological origin. The most practiced processes are that of anaerobic digestion, leading to the production of methane. However; such bioconversion has limited net energy yields. Industrial fermentation targeting value-added bioproducts such as—H2, butanediols; polyhydroxyalkanoates, citric acid, vitamins, enzymes, etc. from biowastes/lignocellulosic substrates have been planned to flourish in a multi-step process or as a “Biorefinery”. Electro-fermentation (EF is one such technology that has attracted much interest due to its ability to boost the microbial metabolism through extracellular electron transfer during fermentation. It has been studied on various acetogens and methanogens, where the enhancement in the biogas yield reached up to 2-fold. EF holds the potential to be used with complex organic materials, leading to the biosynthesis of value-added products at an industrial scale.

  16. The first biopolymer-wrapped non-carbon nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Shamsi, Mohtashim H; Geckeler, Kurt E [Laboratory of Applied Macromolecular Chemistry, Department of Materials Science and Engineering, Gwangju Institute of Science and Technology (GIST), 261-Cheomdan-gwagiro, Buk-gu, Gwangju 500-712 (Korea, Republic of)], E-mail: keg@gist.ac.kr

    2008-02-20

    DNA-wrapped halloysite nanotubes were obtained by a mechanochemical reaction in the solid state. The characterization by scanning electron microscopy showed that the nanotubes were cut into shorter lengths and were completely covered with DNA. This resulted in a high aqueous solubility of the product with stability of the solution for about 6 weeks. The nanotubes were cut to different fractions with lengths of 200-400 nm (30-40%), 400-600 nm (10-20%) and 600-800 nm (5-10%) after ball milling. FTIR spectroscopic analysis shows that the DNA in the product remained intact. This straightforward technique for obtaining water-soluble halloysite nanotubes by a solid-state reaction has great potential for biomedical applications of nanotubes.

  17. The first biopolymer-wrapped non-carbon nanotubes

    International Nuclear Information System (INIS)

    Shamsi, Mohtashim H; Geckeler, Kurt E

    2008-01-01

    DNA-wrapped halloysite nanotubes were obtained by a mechanochemical reaction in the solid state. The characterization by scanning electron microscopy showed that the nanotubes were cut into shorter lengths and were completely covered with DNA. This resulted in a high aqueous solubility of the product with stability of the solution for about 6 weeks. The nanotubes were cut to different fractions with lengths of 200-400 nm (30-40%), 400-600 nm (10-20%) and 600-800 nm (5-10%) after ball milling. FTIR spectroscopic analysis shows that the DNA in the product remained intact. This straightforward technique for obtaining water-soluble halloysite nanotubes by a solid-state reaction has great potential for biomedical applications of nanotubes

  18. Interfacial Healing and Transport Phenomena Modeling ff Biopolymers

    Science.gov (United States)

    Lebron, Karla

    This research focuses on the characterization of bioplastics joined using ultrasonic welding and modeling of temperature distributions and interfacial healing. Polylactic acid (PLA), which is typically derived from starch-rich crops such as corn, was studied. While the measurement of activation energy for interfacial healing at weld interfaces of PLA films has been reported, here, this information is used to predict the weld strength of rigid PLA samples welded by ultrasonics. A characterization of the mechanical properties was completed with a tensile test to determine the effects of amplitude, melt velocity and collapse distance on weld strength. From previous interfacial healing activation energy measurements based on an impulse welding method, it was also possible to predict weld strength. It was found that the most influential parameters were weld time, collapse distance and weld velocity. In general, the model predicted weld strength reasonably well with r2 values between 0.77 and 0.78.

  19. MICROBIAL FERMENTATION OF ABUNDANT BIOPOLYMERS: CELLULOSE AND CHITIN

    Energy Technology Data Exchange (ETDEWEB)

    Leschine, Susan

    2009-10-31

    Our research has dealt with seven major areas of investigation: i) characterization of cellulolytic members of microbial consortia, with special attention recently given to Clostridium phytofermentans, a bacterium that decomposes cellulose and produces uncommonly large amounts of ethanol, ii) investigations of the chitinase system of Cellulomonas uda; including the purification and characterization of ChiA, the major component of this enzyme system, iii) molecular cloning, sequence and structural analysis of the gene that encodes ChiA in C. uda, iv) biofilm formation by C. uda on nutritive surfaces, v) investigations of the effects of humic substances on cellulose degradation by anaerobic cellulolytic microbes, vi) studies of nitrogen metabolism in cellulolytic anaerobes, and vii) understanding the molecular architecture of the multicomplex cellulase-xylanase system of Clostridium papyrosolvens. Also, progress toward completing the research of more recent projects is briefly summarized. Major accomplishments include: 1. Characterization of Clostridium phytofermentans, a cellulose-fermenting, ethanol-producing bacterium from forest soil. The characterization of a new cellulolytic species isolated from a cellulose-decomposing microbial consortium from forest soil was completed. This bacterium is remarkable for the high concentrations of ethanol produced during cellulose fermentation, typically more than twice the concentration produced by other species of cellulolytic clostridia. 2. Examination of the use of chitin as a source of carbon and nitrogen by cellulolytic microbes. We discovered that many cellulolytic anaerobes and facultative aerobes are able to use chitin as a source of both carbon and nitrogen. This major discovery expands our understanding of the biology of cellulose-fermenting bacteria and may lead to new applications for these microbes. 3. Comparative studies of the cellulase and chitinase systems of Cellulomonas uda. Results of these studies indicate that the chitinase and cellulase systems of this bacterium are distinct in terms of the proteins involved and the regulation of their production. 4. Characterization of the chitinase system of C. uda. A 70,000-Mr endochitinase, designated ChiA, was purified from C. uda culture supernatant fluids and characterized. 5. Analysis of chiA, which codes for the major enzymatic component of the chitinase system of C. uda. The gene encoding the endochitinase ChiA in C. uda was cloned, its complete nucleotide sequence was determined and its implications were investigated. 6. Formation of biofilms by C. uda on cellulose and chitin. Microscopic observations indicated that, under conditions of nitrogen limitation, C. uda cells grew as a biofilm attached tightly to the surface of cellulose or chitin. 7. Development of tools for a genetic approach to studies of cellulose fermentation by cellulolytic clostridia. We have explored the potential of various techniques, and obtained evidence indicating that Tn916 mutagenesis may be particularly effective in this regard. As part of this research, we identified the presence of a plasmid in one strain, which was cloned, sequenced, and analyzed for its utility in the development of vectors for genetic studies. 8. Effects of humic substances on cellulose degradation by anaerobic cellulolytic microbes. We determined that humic substances play an important role in the anaerobic cellulose decomposition and in the physiology of cellulose-fermenting soil bacteria. 9. Nitrogenases of cellulolytic clostridia. We described a nitrogenase gene from a cellulolytic clostridium and presented evidence, based on sequence analyses and conserved gene order, for lateral gene transfer between this bacterium and a methanogenic archaeon. 10. Characterization of Clostridium hungatei, a new N2-fixing cellulolytic species isolated from a methanogenic consortium from soil. 11. Understanding the molecular architecture of the multicomplex cellulase-xylanase system of Clostridium papyrosolvens. We discovered that C. papyrosolvens produces a multiprotein, multicomplex cellulase-xylanase enzyme system that hydrolyzes crystalline cellulose, and we have described this system in detail.

  20. USING BIOPOLYMERS TO STABILIZE THE PROTEIN OXYGEN FOAM

    Directory of Open Access Journals (Sweden)

    N. V. Nepovinnyh

    2013-01-01

    Full Text Available The cottage cheese whey as an oxygen cocktail foaming base and natural juices as a flavoring ingredient are analyzed. The lifetime of foam generated by the serum proteins is not long: foam falls off rapidly; because from the foam liquid is released (syneresis. The effects of plant polysaccharides on the stabilization of the protein foam oxygen cocktail is studied. It was shown that the use of plant polysaccharides (guar gum, high methoxyl citrus pectin, locust been gum prolong the life of the foam up to 20 times, compared with conventional blowing agents. It was found that oxygen foam properties depend on the molecular weight of guar gum.

  1. Preparation of the Jaws Damaged Parts from Composite Biopolymers Materials

    Directory of Open Access Journals (Sweden)

    Riyam A. Al-husseini

    2017-10-01

    Full Text Available Composite materials composing of fusing two materials or more are disaccorded in mechanical and physical characteristics, The studied the effect of changing in the reinforcement percentage by Hydroxyapatite Prepared nano world via the size of the nanoscale powder manufacturing manner chemical precipitation and microwave powders were two types their preparations have been from natural sources: the first type of eggshells and the other from the bones of fish in mechanical Properties which include the tensile strength, elastic modulus, elongation, hardness and tear for composite material consisting of Silicone rubber (SIR reinforced by (µ-n-HA, after strengthening silicone rubber Protect proportions (5,10,15,20 wt% of Article achieved results that increase the additive lead to increased hardness while tougher and modulus of elasticity decreases with added as shown in the diagrams.

  2. Electrochemical and Thermal Studies of Prepared Conducting Chitosan Biopolymer Film

    International Nuclear Information System (INIS)

    Hlaing Hlaing Oo; Kyaw Naing; Kyaw Myo Naing; Tin Tin Aye; Nyunt Wynn

    2005-09-01

    In this paper, chitosan based conducting bipolymer films were prepared by casting and solvent evaporating technique. All prepared chitosan films were of pale yellow colour, transparent, and smooth. Sulphuric acid was chosen as the cross-linking agent. It enhanced conduction pathway in cross-linked chitosan films. Mechanical properties, solid-state, and thermal behavior of prepared chitosan fimls were studied by means of a material testing machine, powder X-ray diffractometry (XRD), thermogravimetric analysis (TG-DTG), and differential scanning calorimetry (DSC). By the XRD diffraction pattern, high molecular weight of chitosan product indicates the semi-crystalline nature, but the prepared chitosan film and doped chitosan film indicate significantly lower in crystallinity prove which of the amorphous characteristics. In addition, DSC thermogram of pure chitosan film exhibited exothermic peak around at 300 C, indicating polymer decomposition of chitosan molecules in chitosan films. Furthermore, these DSC thermograms clearly showed that while pure chitosan film display exothermal decomposition, the doped chitosan films mainly endothermic characteristics. The ionic conductivity of doped chitosan films were in the order of 10 to 10 S cm , which is in the range of semi-conductor. These results showed that cross-linked chitoson films may be used as polymer electrolyte film to fabricate solid state electrochemical cells

  3. Composite biopolymers for bone regeneration enhancement in bony defects.

    Science.gov (United States)

    Jahan, K; Tabrizian, M

    2016-01-01

    For the past century, various biomaterials have been used in the treatment of bone defects and fractures. Their role as potential substitutes for human bone grafts increases as donors become scarce. Metals, ceramics and polymers are all materials that confer different advantages to bone scaffold development. For instance, biocompatibility is a highly desirable property for which naturally-derived polymers are renowned. While generally applied separately, the use of biomaterials, in particular natural polymers, is likely to change, as biomaterial research moves towards mixing different types of materials in order to maximize their individual strengths. This review focuses on osteoconductive biocomposite scaffolds which are constructed around natural polymers and their performance at the in vitro/in vivo stages and in clinical trials.

  4. Feature Tracking for High Speed AFM Imaging of Biopolymers.

    Science.gov (United States)

    Hartman, Brett; Andersson, Sean B

    2018-03-31

    The scanning speed of atomic force microscopes continues to advance with some current commercial microscopes achieving on the order of one frame per second and at least one reaching 10 frames per second. Despite the success of these instruments, even higher frame rates are needed with scan ranges larger than are currently achievable. Moreover, there is a significant installed base of slower instruments that would benefit from algorithmic approaches to increasing their frame rate without requiring significant hardware modifications. In this paper, we present an experimental demonstration of high speed scanning on an existing, non-high speed instrument, through the use of a feedback-based, feature-tracking algorithm that reduces imaging time by focusing on features of interest to reduce the total imaging area. Experiments on both circular and square gratings, as well as silicon steps and DNA strands show a reduction in imaging time by a factor of 3-12 over raster scanning, depending on the parameters chosen.

  5. Encapsulation of iron nanoparticles in alginate biopolymer for trichloroethylene remediation

    International Nuclear Information System (INIS)

    Bezbaruah, Achintya N.; Shanbhogue, Sai Sharanya; Simsek, Senay; Khan, Eakalak

    2011-01-01

    Nanoscale zero-valent iron (NZVI) particles (10–90 nm) were encapsulated in biodegradable calcium-alginate capsules for the first time for application in environmental remediation. Encapsulation is expected to offers distinct advances over entrapment. Trichloroethylene (TCE) degradation was 89–91% in 2 h, and the reaction followed pseudo first order kinetics for encapsulated NZVI systems with an observed reaction rate constant (k obs ) of 1.92–3.23 × 10 −2 min −1 and a surface normalized reaction rate constant (k sa ) of 1.02–1.72 × 10 −3 L m −2 min −1 . TCE degradation reaction rates for encapsulated and bare NZVI were similar indicating no adverse affects of encapsulation on degradation kinetics. The shelf-life of encapsulated NZVI was found to be four months with little decrease in TCE removal efficiency.

  6. Frequency-dependent micromechanics of cellularized biopolymer networks

    Science.gov (United States)

    Jones, Chris; Kim, Jihan; McIntyre, David; Sun, Bo

    Mechanical interactions between cells and the extracellular matrix (ECM) influence many cellular behaviors such as growth, differentiation, and migration. These are dynamic processes in which the cells actively remodel the ECM. Reconstituted collagen gel is a common model ECM for studying cell-ECM interactions in vitro because collagen is the most abundant component of mammalian ECM and gives the ECM its material stiffness. We embed micron-sized particles in collagen and use holographic optical tweezers to apply forces to the particles in multiple directions and over a range of frequencies up to 10 Hz. We calculate the local compliance and show that it is dependent on both the direction and frequency of the applied force. Performing the same measurement on many particles allows us to characterize the spatial inhomogeneity of the mechanical properties and shows that the compliance decreases at higher frequencies. Performing these measurements on cell-populated collagen gels shows that cellular remodeling of the ECM changes the mechanical properties of the collagen and we investigate whether this change is dependent on the local strain and distance from nearby cells.

  7. Permeation of "Hydromer" Film: An Elastomeric Hydrogen-Capturing Biopolymer.

    Energy Technology Data Exchange (ETDEWEB)

    Karnesky, Richard A. [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Friddle, Raymond William [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Whaley, Josh A. [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Smith, Geoffrey [New Mexico State Univ., Las Cruces, NM (United States)

    2015-12-01

    This report analyzes the permeation resistance of a novel and proprietary polymer coating for hydrogen isotope resistance that was developed by New Mexico State University. Thermal gravimetric analysis and thermal desoprtion spectroscopy show the polymer is stable thermally to approximately 250 deg C. Deuterium gas-driven permeation experiments were conducted at Sandia to explore early evidence (obtained using Brunauer - Emmett - Teller) of the polymer's strong resistance to hydrogen. With a relatively small amount of the polymer in solution (0.15%), a decrease in diffusion by a factor of 2 is observed at 100 and 150 deg C. While there was very little reduction in permeability, the preliminary findings reported here are meant to demonstrate the sensitivity of Sandia's permeation measurements and are intended to motivate the future exploration of thicker barriers with greater polymer coverage.

  8. Cyclic Voltammetry of Biopolymer Heparin at PVC Plasticized Liquid Membrane

    Czech Academy of Sciences Publication Activity Database

    Samec, Zdeněk; Trojánek, Antonín; Langmaier, Jan; Samcová, E.

    2003-01-01

    Roč. 5, - (2003), s. 867-870 ISSN 1388-2481 R&D Projects: GA ČR GA203/04/0424 Institutional research plan: CEZ:AV0Z4040901 Keywords : cyclic voltammetry * PVC plasticized liquit membrane * heparin Subject RIV: CG - Electrochemistry Impact factor: 2.300, year: 2003

  9. Start a Research on Biopolymer Polyhydroxyalkanoate (PHA: A Review

    Directory of Open Access Journals (Sweden)

    Giin-Yu Amy Tan

    2014-03-01

    Full Text Available With the impending fossil fuel crisis, the search for and development of alternative chemical/material substitutes is pivotal in reducing mankind’s dependency on fossil resources. One of the potential substitute candidates is polyhydroxyalkanoate (PHA. PHA is a carbon-neutral and valuable polymer that could be produced from many renewable carbon sources by microorganisms, making it a sustainable and environmental-friendly material. At present, PHA is not cost competitive compared to fossil-derived products. Encouraging and intensifying research work on PHA is anticipated to enhance its economic viability in the future. The development of various biomolecular and chemical techniques for PHA analysis has led to the identification of many PHA-producing microbial strains, some of which are deposited in culture collections. Research work on PHA could be rapidly initiated with these ready-to-use techniques and microbial strains. This review aims to facilitate the start-up of PHA research by providing a summary of commercially available PHA-accumulating microbial cultures, PHA biosynthetic pathways, and methods for PHA detection, extraction and analysis.

  10. Physicochemical Properties of Biopolymer Hydrogels Treated by Direct Electric Current

    Directory of Open Access Journals (Sweden)

    Żaneta Król

    2016-07-01

    Full Text Available The objective of this study was to evaluate the changes within the physicochemical properties of gelatine (2%; 4%; 8%, carrageenan (1.5%; 2%; 2.5% and sodium alginate (0.75%; 1%; 1.25% hydrogels with different sodium chloride concentrations that were triggered by applying direct current (DC of 400 mA for a duration of five minutes. There were three types of gels prepared for the purpose of the study: C, control; H, gels on the basis of hydrosols that were treated with DC; and G, gels treated with DC. In the course of the study, the authors carried out the following analyses: Texture Profile Analysis (TPA, Fourier Transform Infrared spectroscopy (FTIR, Scanning Electron Microscopy (SEM and Swelling Ratio (SR. Furthermore, the color and pH of hydrogels were measured. The FTIR spectra showed that the structures of gelatine, carrageenan and sodium alginate do not significantly change upon applying DC. The results of TPA, SR, color and pH measurement indicate that hydrogels’ properties are significantly dependent on the type of polymer, its concentration and the type of the gel. By changing those parameters, the characteristics of such gels can be additionally tuned, which extends their applicability, e.g., in the food industry. Moreover, the analysis revealed that SR of H gel gelatine after 72 h of storage was 1.84-times higher than SR of the control sample, which indicated that this gel may be considered as a possible component for wound dressing materials.

  11. Functional Interactions Between Early Biopolymers and Primitive Cells

    Science.gov (United States)

    Heili, J.; Gaut, N.; Han, Q.; Gomez-Garcia, J.; Szostak, J. W.; Adamala, K. P.; Engelhart, A. E.

    2017-07-01

    Recently, we have demonstrated that compartmentalized biomolecules exhibit functional behaviors not observed in bulk solution. We suggest that numerous synthetic and regulatory processes might have been enabled by membrane-biomolecule interactions.

  12. Formation and rupture of Ca(2+) induced pectin biopolymer gels.

    Science.gov (United States)

    Basak, Rajib; Bandyopadhyay, Ranjini

    2014-10-07

    When calcium salts are added to an aqueous solution of polysaccharide pectin, ionic cross-links form between pectin chains, giving rise to a gel network in dilute solution. In this work, dynamic light scattering (DLS) is employed to study the microscopic dynamics of the fractal aggregates (flocs) that constitute the gels, while rheological measurements are carried out to study the process of gel rupture. As the calcium salt concentration is increased, DLS experiments reveal that the polydispersity of the flocs increase simultaneously with the characteristic relaxation times of the gel network. Above a critical salt concentration, the flocs become interlinked to form a reaction-limited fractal gel network. Rheological studies demonstrate that the limits of the linear rheological response and the critical stresses required to rupture these networks both decrease with the increase in salt concentration. These features indicate that the ion-mediated pectin gels studied here lie in a 'strong link' regime that is characterised by inter-floc links that are stronger than intra-floc links. A scaling analysis of the experimental data presented here demonstrates that the elasticities of the individual fractal flocs exhibit power-law dependences on the added salt concentration. We conclude that when both pectin and salt concentrations are increased, the number of fractal flocs of pectin increases simultaneously with the density of crosslinks, giving rise to very large values of the bulk elastic modulus.

  13. Effect of citric acid on noncovalent interactions in biopolymer jellies

    Directory of Open Access Journals (Sweden)

    Kuanyzhbek Musabekov

    2015-09-01

    Full Text Available The effect of citric acid on the formation of gels based on gelatine, melon pulp and sugar has been studied. It is found that the structuring of gelatin the presence of melon pulp is due to hydrogen bonds between the amino acids of gelatin and pectin melon by hydrogen bonds. It is shown that the structuring of gelatin and gelatin – melon pulp depends on the concentration of sugar. The addition of acid in the pectin-gelatin composition reduces the pH, the solubility of pectin and accelerates the formation of jelly. This is due to the fact that in the presence of citric acid reduced the degree of dissociation of galacturonic acid. The intensity of the effect of citric acid on the structure in the presence of melon pulp could be explained by the formation of hydrogen bonds between pectin and citric acid.

  14. Interaction of nogalamycin and analogs with DNA and other biopolymers

    Energy Technology Data Exchange (ETDEWEB)

    Krueger, W C [Univ. of Minnesota, Minneapolis; Pschigoda, L M; Schpok, S L.F.; Moscowitz, A.; McGovren, J P; Neta, P; Merritt, M V; Li, L H

    1981-01-01

    The interaction with calf thymus DNA of the anthracycline antibiotics, nogalamycin and its analogs, was studied by electronic absorption, circular dichroism (CD), thermal denaturation, solvent partition and pulse radiolysis techniques. The Scatchard, thermal denaturation (..delta..T/sub m/), difference circular dichroism (..delta..CD) and solvent partition binding parameters gave the same order of relative binding on a given lot of DNA, but some parameters were DNA-lot-dependent. In general, molecules containing the sugar moiety nogalose at C-7 or those having the natural or dis stereochemistry of nogalamycin at C-7 bound more strongly to DNA than did the molecules lacking nogalose or those with the opposite configuration at C-7 (con stereochemistry). This stereochemical-binding correlation differs from that found for adriamycin which has the con stereochemistry, but which binds strongly to DNA. Scatchard binding parameters could not be obtained from the pulse radiolysis or solvent partition techniques because of solubility difficulties.

  15. Electrospinning of oriented and nonoriented ultrafine fibers of biopolymers

    Science.gov (United States)

    Vu, David

    2005-07-01

    Chitosan has long been known as a biocompatible and biodegradable material suitable for tissue engineering applications. Unfortunately, conventional chitosan solutions cannot be used for electrospinning due to their high conductivity, viscosity and surface tension. We have developed a method to produce clear chitosan solutions with conductivities, surface tension and viscosities that facilitate their processing into micron and submicron fibers via electrospinning. Acetic acid, carbon dioxide and organic solvents are key ingredients in preparing the chitosan solutions. Oriented and non oriented chitosan fibers were produced with the ultimate goal of designing a suitable tissue engineering scaffold. Circularly oriented, continuous, and aligned nanofibers were produced via this technique in the form of a thin membrane or fibrous "mat". Chitosan fiber diameters ranged from 5 micrometers down to 100 nanometers. The structure and mechanical properties of oriented and randomly aligned chitosan fiber deposits could potentially be exploited for cartilage tissue engineering. Ultrafine fibers of starch acetate (SA) also were prepared by the electrospinning process. In this study, solvent mixtures based on DMF, DMSO, pyrindine, acetic acid, acetone, THF, DMC, chloroform were used. A two-solvent formulation was used to study the effect of viscosity, surface tension, and conductivity to the fiber diameter. Also, water and ethanol were used to decrease the boiling point of the solvent, and to make bundled fibers. Several techniques such as scanning electron microscopy, conductmetry, viscometry, and tensiometry were used in this study. The results showed that the combined effects of viscosity, surface tension, and conductivity are of great importance in controlling the diameter of the fibers. We were able to produce SA fibers that was less than 40 nm in diameter. The dependence of fiber diameter on flow-rate, electric field and solvents also was investigated. A rotating disk and a rotating wheel were proposed for collecting oriented electrospun fibers. Results showed that the two methods have some advantages over methods previously reported in the literature. We also proposed a mechanism of formation of cross-linked oriented fibers. The processing temperature played an important role in controlling the morphology of the fibers. The influence of operating parameters on the electrospinning process also was studied.

  16. Chitin and chitosan as functional biopolymers for industrial applications

    NARCIS (Netherlands)

    kardas, I.; Struzczyk, M.H.; Kucharska, M.; Broek, van den L.A.M.; Dam, van J.E.G.

    2012-01-01

    Chitin research and development seems to be under intensive progress during the last years. Attractive properties of chitin and its derivative—chitosan, for example, biological behavior, and development of their applications caused increased interest of scientists and companies. More and more

  17. Biopolymer system for permeability modification in porous media

    Energy Technology Data Exchange (ETDEWEB)

    Stepp, A.K.; Bryant, R.S.; Llave, F.M. [BMD-Oklahoma, Inc., Bartlesville, OK (United States)] [and others

    1995-12-31

    New technologies are needed to reduce the current high rate of well abandonment. Improved sweep efficiency, reservoir conformance, and permeability modification can have a significant impact on oil recovery processes. Microorganisms can be used to selectively plug high-permeability zones to improve sweep efficiency and impart conformance control. Studies of a promising microbial system for polymer production were conducted to evaluate reservoir conditions in which this system would be effective. Factors which can affect microbial growth and polymer production include salinity, pH, temperature, divalent ions, presence of residual oil, and rock matrix. Flask tests and coreflooding experiments were conducted to optimize and evaluate the effectiveness of this system. Nuclear magnetic resonance imaging (NMRI) was used to visualize microbial polymer production in porous media. Changes in fluid distribution within the pore system of the core were detected.

  18. Biofunctionalized Nanofibers Using Arthrospira (Spirulina Biomass and Biopolymer

    Directory of Open Access Journals (Sweden)

    Michele Greque de Morais

    2015-01-01

    Full Text Available Electrospun nanofibers composed of polymers have been extensively researched because of their scientific and technical applications. Commercially available polyhydroxybutyrate (PHB and polyhydroxybutyrate-co-valerate (PHB-HV copolymers are good choices for such nanofibers. We used a highly integrated method, by adjusting the properties of the spinning solutions, where the cyanophyte Arthrospira (formally Spirulina was the single source for nanofiber biofunctionalization. We investigated nanofibers using PHB extracted from Spirulina and the bacteria Cupriavidus necator and compared the nanofibers to those made from commercially available PHB and PHB-HV. Our study assessed nanofiber formation and their selected thermal, mechanical, and optical properties. We found that nanofibers produced from Spirulina PHB and biofunctionalized with Spirulina biomass exhibited properties which were equal to or better than nanofibers made with commercially available PHB or PHB-HV. Our methodology is highly promising for nanofiber production and biofunctionalization and can be used in many industrial and life science applications.

  19. Physicochemical Characterization of Biopolymer Chitosan Extracted from Shrimp Shells

    Directory of Open Access Journals (Sweden)

    Nezamaddin Mengelizadeh

    2015-02-01

    Full Text Available Chitosan is a deacetylated derivative of chitin, which is a naturally abundant mucopolysaccharide, supporting the matter of crustaceans, insects, and fungi. Because of its unique properties, such as non-toxicity, biodegradability, and biocompatibility, chitosan has a wide range of applications in various fields. The objective of the present work is to extract the polymer chitosan from Persian Gulf shrimp shells. In order to determine the physicochemical characteristics of the extracted chitosan, degree of deacetylation, molecular weight, water and fat binding capacities extraction rate, and apparent viscosity were measured using a variety of techniques including viscometry, weight measurement method and Fourier transform infrared spectroscopy (FTIR. The results of the study of the physicochemical properties, molecular weight (6.7×105 Da, degree of deacetylation (57%, ash content as well as yield (0.5% of the prepared chitosan indicated that shrimp processing wastes (shrimp shells are a good source of chitosan. The water binding capacity (521% and fat binding capacity (327% of the prepared chitosan are in good agreement with the other studies. The elemental analysis showed the C, H and N contents of 35.92%, 7.02%, and 8.66%, respectively. In this study, the antimicrobial activity of chitosan was evaluated against Staphylococcus aureus and Escherichia coli. The results indicated the high potential of chitosan as an antibacterial agent. Moreover, the results of the study indicated that shrimp shells are a rich source of chitin as 25.21% of the shell’s dry weight.

  20. Estudo comparativo macroscópico dos defeitos osteocondrais produzidos em fêmures de coelhos preenchidos com gel de biopolímero da cana-de-açúcar Comparative macroscopic study of osteochondral defects produced in femurs of rabbits repaired with biopolymer gel cane sugar

    Directory of Open Access Journals (Sweden)

    Paulo Cezar Vidal Carneiro de Albuquerque

    2011-10-01

    Full Text Available OBJETIVO: Estudar a superfície, coloração, continuidade, consistência e cicatrização dos defeitos osteocondrais produzidos em côndilos femorais de coelhos preenchidos com o gel de biopolímero da cana-de-açúcar (GBPCA nos períodos de 90, 120 e 180 dias e comparar com o grupo Controle. MÉTODO: Foram estudados 16 coelhos, adultos entre seis e sete meses, da raça Nova Zelândia, brancos,, com peso variando entre 2 e 2,5kg e sem alterações no aparelho locomotor. Em todos os animais foi feito um defeito com trefina com 3,2mm de diâmetro por 4mm de profundidade nos côndilos femorais dos joelhos direito e esquerdo. Os animais foram divididos em dois grupos: Estudo - joelho direito, côndilos medial e lateral, preenchimento com GBPCA; Controle - joelho esquerdo, côndilos medial e lateral, submetidos à cicatrização natural e analisados nos períodos de 90, 120 e 180 dias após a cirurgia. Após a eutanásia, ressecaram-se as peças anatômicas, que foram imersas em solução de Bouin, para posterior fotografia com câmara Nikon Coolpix 5400® acoplada a lupa estereoscópica Nikon SM2800® para análise da superfície, coloração, consistência, continuidade e cicatrização. RESULTADOS: Foram avaliados pelo teste do Qui-quadrado. Não houve diferenças significantes na avaliação macroscópica da cicatrização entre os grupos Estudo e Controle. CONCLUSÃO: No que se refere à superfície, coloração, consistência, continuidade e cicatrização dos defeitos, a macroscopia do tecido reparado com GBPCA se mostrou semelhante à do grupo Controle.OBJECTIVE: To study the surface, coloring, consistency, continuity and healing of osteochondral defects produced in the femoral condyles of rabbits and filled with sugar cane biopolymer gel (SCBG, after 90, 120 and 180 days, and in comparison with a control group. METHOD: Sixteen adult New Zealand white rabbits aged 6 to 7 months, weighing between 2 and 2.5 kg and without locomotor system

  1. Biopolymer Production Kinetics of Mixed Culture Using Wastewater Sludge as a Raw Material and the Effect of Different Cations on Biopolymer Applications in Water and Wastewater Treatment.

    Science.gov (United States)

    More, T T; Yan, S; Tyagi, R D; Surampalli, R Y

    2016-05-01

    Thirteen extracellular polymeric substances (EPS) producing bacterial strains were cultivated (as mixed culture) in the sterilized sludge (suspended solids of 25 g/L) and the batch fermentation was carried out. Mixed culture revealed a high specific growth rate of 0.35/hr. The EPS production rate was higher up to 24 hours, which gradually decreased with further incubation. The kinetic estimates demonstrated growth-associated EPS production. Broth EPS revealed higher flocculation activity when combined with different cations (Ca(2+), Mg(2+), Fe(3+), and Al(3+)) in river water (≥90%), municipal wastewater (≥90%), and brewery wastewater (≥80%), respectively. A low dose (5 to 40 mg/L) of trivalent cations was required to achieve higher flocculation compared to the divalent cations (50 to 250 mg/L). Flocculation performance of EPS was comparable to Magnafloc-155 (chemical polymer) and, hence, it could be used as a flocculant.

  2. Carbon Microfibers with Hierarchical Porous Structure from Electrospun Fiber-Like Natural Biopolymer

    Science.gov (United States)

    Liang, Yeru; Wu, Dingcai; Fu, Ruowen

    2013-01-01

    Electrospinning offers a powerful route for building one-dimensional (1D) micro/nanostructures, but a common requirement for toxic or corrosive organic solvents during the preparation of precursor solution has limited their large scale synthesis and broad applications. Here we report a facile and low-cost way to prepare 1D porous carbon microfibers by using an electrospun fiber-like natural product, i.e., silk cocoon, as precursor. We surprisingly found that by utilizing a simple carbonization treatment, the cocoon microfiber can be directly transformed into 1D carbon microfiber of ca. 6 μm diameter with a unique three-dimensional porous network structure composed of interconnected carbon nanoparticles of 10~40 nm diameter. We further showed that the as-prepared carbon product presents superior electrochemical performance as binder-free electrodes of supercapacitors and good adsorption property toward organic vapor.

  3. Novel and simple route to fabricate fully biocompatible plasmonic mushroom arrays adhered on silk biopolymer

    Science.gov (United States)

    Park, Joonhan; Choi, Yunkyoung; Lee, Myungjae; Jeon, Heonsu; Kim, Sunghwan

    2014-12-01

    A fully biocompatible plasmonic quasi-3D nanostructure is demonstrated by a simple and reliable fabrication method using strong adhesion between gold and silk fibroin. The quasi-3D nature gives rise to complex photonic responses in reflectance that are prospectively useful in bio/chemical sensing applications. Laser interference lithography is utilized to fabricate large-area plasmonic nanostructures.A fully biocompatible plasmonic quasi-3D nanostructure is demonstrated by a simple and reliable fabrication method using strong adhesion between gold and silk fibroin. The quasi-3D nature gives rise to complex photonic responses in reflectance that are prospectively useful in bio/chemical sensing applications. Laser interference lithography is utilized to fabricate large-area plasmonic nanostructures. Electronic supplementary information (ESI) available: The incident angle dependence of reflectance spectra and the atomic force microscopy image of the Au nanoparticle array on a silk film after 1 hour of ultrasonication. See DOI: 10.1039/c4nr05172f

  4. Combining flagelliform and dragline spider silk motifs to produce tunable synthetic biopolymer fibers.

    Science.gov (United States)

    Teulé, Florence; Addison, Bennett; Cooper, Alyssa R; Ayon, Joel; Henning, Robert W; Benmore, Chris J; Holland, Gregory P; Yarger, Jeffery L; Lewis, Randolph V

    2012-06-01

    The two Flag/MaSp 2 silk proteins produced recombinantly were based on the basic consensus repeat of the dragline silk spidroin 2 protein (MaSp 2) from the Nephila clavipes orb weaving spider. However, the proline-containing pentapeptides juxtaposed to the polyalanine segments resembled those found in the flagelliform silk protein (Flag) composing the web spiral: (GPGGX(1) GPGGX(2))(2) with X(1) /X(2) = A/A or Y/S. Fibers were formed from protein films in aqueous solutions or extruded from resolubilized protein dopes in organic conditions when the Flag motif was (GPGGX(1) GPGGX(2))(2) with X(1) /X(2) = Y/S or A/A, respectively. Post-fiber processing involved similar drawing ratios (2-2.5×) before or after water-treatment. Structural (ssNMR and XRD) and morphological (SEM) changes in the fibers were compared to the mechanical properties of the fibers at each step. Nuclear magnetic resonance indicated that the fraction of β-sheet nanocrystals in the polyalanine regions formed upon extrusion, increased during stretching, and was maximized after water-treatment. X-ray diffraction showed that nanocrystallite orientation parallel to the fiber axis increased the ultimate strength and initial stiffness of the fibers. Water furthered nanocrystal orientation and three-dimensional growth while plasticizing the amorphous regions, thus producing tougher fibers due to increased extensibility. These fibers were highly hygroscopic and had similar internal network organization, thus similar range of mechanical properties that depended on their diameters. The overall structure of the consensus repeat of the silk-like protein dictated the mechanical properties of the fibers while protein molecular weight limited these same properties. Subtle structural motif re-design impacted protein self-assembly mechanisms and requirements for fiber formation. Copyright © 2011 Wiley Periodicals, Inc.

  5. Rotational-echo Double-resonance in Complex Biopolymers: a Study of Nephila Clavipes Dragline Silk

    International Nuclear Information System (INIS)

    Michal, Carl A.; Jelinski, Lynn W.

    1998-01-01

    Rotational-Echo Double-Resonance (REDOR) NMR on strategically 13C and 15N labeled samples is used to study the conformation of the LGXQ (X = S, G, or N) motif in the major ampullate gland dragline silk from the spider Nephila clavipes. A method is described for calculating REDOR dephasing curves suitable for background subtractions, using probability distributions of nitrogen atoms surrounding a given carbon site, which are developed from coordinates in the Brookhaven Protein Data Bank. The validity of the method is established by comparison to dephasings observed from natural abundance 13C peaks for G and A. Straightforward fitting of universal REDOR dephasing curves to the background corrected peaks of interest provide results which are not self-consistent, and a more sophisticated analysis is developed which better accounts for 15N labels which have scrambled from the intended positions. While there is likely some heterogeneity in the structures formed by the LGXQ sequences, the data indicate that they all form compact turn-like structures

  6. Biopolymer-stabilized Pt nanoparticles colloid: a highly active and recyclable catalyst for biphasic catalysis

    International Nuclear Information System (INIS)

    Wang, Yujia; Shen, Yueyue; Qiu, Yunfei; Zhang, Ting; Liao, Yang; Zhao, Shilin; Ma, Jun; Mao, Hui

    2016-01-01

    Noble metal nanoparticles are promising candidates to replace conventional bulk counterparts owing to their high activity and selectivity. To enable catalyst recovery, noble metal nanoparticles are often supported onto solid matrices to prepare heterogeneous catalyst. Although recycle of noble metal nanoparticles is realized by heterogenization, a loss of activity is usually encountered. In the present investigation, Pt nanoparticles with tunable particle size (1.85–2.80 nm) were facilely prepared by using polyphenols as amphiphilic stabilizers. The as-prepared Pt nanoparticles colloid solution could be used as highly active catalyst in aqueous–organic biphasic catalysis. The phenolic hydroxyls of polyphenols could constrain Pt nanoparticles in aqueous phase, and simultaneously, the aromatic scaffold of polyphenols ensured effective interactions between substrates and Pt nanoparticles. As a consequence, the obtained polyphenols-stabilized Pt nanoparticles exhibited high activity and cycling stability in biphasic hydrogenation of a series of unsaturated compounds. Compared with conventional heterogeneous Pt-C and Pt-Al 2 O 3 catalysts, polyphenols-stabilized Pt nanoparticles showed obvious advantage both in activity and cycling stability.

  7. Biopolymer Production by Bacterial Enrichment Cultures Using Non-Fermented Substrates

    NARCIS (Netherlands)

    Moralejo Gárate, H.

    2014-01-01

    Polyhydroxyalkanotes (PHAs) are naturally occurring polymers synthesized by a wide range of microorganisms. Their physiological role is to act as carbon and energy reserves, and their mechanical and physical properties are similar to those of petrochemical plastics. PHAs can be synthesized from

  8. The Effects of Single-Wall Carbon Nanotubes on the Shear Piezoelectricity of Biopolymers

    Science.gov (United States)

    Lovell, Conrad; Fitz-Gerald, James M.; Harrison, Joycelyn S.; Park, Cheol

    2008-01-01

    Shear piezoelectricity was investigated in a series of composites consisting of increased loadings of single-wall carbon nanotubes (SWCNTs) in poly (gamma-benzyl-L-glutamate), or PBLG. The effects of the SWCNTs on this material property in PBLG will be discussed. Their influence on the morphology of the polymer (degree of orientation and crystallinity), and electrical and dielectric properties of the composite will be reported

  9. Natural emulsifiers - Biosurfactants, phospholipids, biopolymers, and colloidal particles: Molecular and physicochemical basis of functional performance.

    Science.gov (United States)

    McClements, David Julian; Gumus, Cansu Ekin

    2016-08-01

    There is increasing consumer pressure for commercial products that are more natural, sustainable, and environmentally friendly, including foods, cosmetics, detergents, and personal care products. Industry has responded by trying to identify natural alternatives to synthetic functional ingredients within these products. The focus of this review article is on the replacement of synthetic surfactants with natural emulsifiers, such as amphiphilic proteins, polysaccharides, biosurfactants, phospholipids, and bioparticles. In particular, the physicochemical basis of emulsion formation and stabilization by natural emulsifiers is discussed, and the benefits and limitations of different natural emulsifiers are compared. Surface-active polysaccharides typically have to be used at relatively high levels to produce small droplets, but the droplets formed are highly resistant to environmental changes. Conversely, surface-active proteins are typically utilized at low levels, but the droplets formed are highly sensitive to changes in pH, ionic strength, and temperature. Certain phospholipids are capable of producing small oil droplets during homogenization, but again the droplets formed are highly sensitive to changes in environmental conditions. Biosurfactants (saponins) can be utilized at low levels to form fine oil droplets that remain stable over a range of environmental conditions. Some nature-derived nanoparticles (e.g., cellulose, chitosan, and starch) are effective at stabilizing emulsions containing relatively large oil droplets. Future research is encouraged to identify, isolate, purify, and characterize new types of natural emulsifier, and to test their efficacy in food, cosmetic, detergent, personal care, and other products. Copyright © 2016 Elsevier B.V. All rights reserved.

  10. Engineering cell factories for producing building block chemicals for bio-polymer synthesis

    OpenAIRE

    Tsuge, Yota; Kawaguchi, Hideo; Sasaki, Kengo; Kondo, Akihiko

    2016-01-01

    Synthetic polymers are widely used in daily life. Due to increasing environmental concerns related to global warming and the depletion of oil reserves, the development of microbial-based fermentation processes for the production of polymer building block chemicals from renewable resources is desirable to replace current petroleum-based methods. To this end, strains that efficiently produce the target chemicals at high yields and productivity are needed. Recent advances in metabolic engineerin...

  11. Engineering cell factories for producing building block chemicals for bio-polymer synthesis.

    Science.gov (United States)

    Tsuge, Yota; Kawaguchi, Hideo; Sasaki, Kengo; Kondo, Akihiko

    2016-01-21

    Synthetic polymers are widely used in daily life. Due to increasing environmental concerns related to global warming and the depletion of oil reserves, the development of microbial-based fermentation processes for the production of polymer building block chemicals from renewable resources is desirable to replace current petroleum-based methods. To this end, strains that efficiently produce the target chemicals at high yields and productivity are needed. Recent advances in metabolic engineering have enabled the biosynthesis of polymer compounds at high yield and productivities by governing the carbon flux towards the target chemicals. Using these methods, microbial strains have been engineered to produce monomer chemicals for replacing traditional petroleum-derived aliphatic polymers. These developments also raise the possibility of microbial production of aromatic chemicals for synthesizing high-performance polymers with desirable properties, such as ultraviolet absorbance, high thermal resistance, and mechanical strength. In the present review, we summarize recent progress in metabolic engineering approaches to optimize microbial strains for producing building blocks to synthesize aliphatic and high-performance aromatic polymers.

  12. Influence of storage period on properties of biopolymer packaging materials and pouches

    Directory of Open Access Journals (Sweden)

    Bulut Sandra N.

    2017-01-01

    Full Text Available Bilayer biodegradable films based on pumpkin oil cake (PuOC and zein, as well as pouches made from these materials, were prepared, and the changes of their mechanical, physicochemical and barrier properties were analyzed during four weeks of storage. Heat seal quality of formed pouches and composition of the gas atmosphere in the pouches were also monitored. The results showed that the bilayer film had a thickness of 300 ± 10 (μm, and no its changes were observed during the storage time. The tensile strength of the tested film increased slightly in the third week, but the elongation at break showed a decreasing trend during the whole storage period. The decreases in the moisture content, total soluble matter and swelling of the obtained film, were also observed. After one month of storage, the O2 transmission rate of tested films, increased from 27 to 64 (ml/m2 24h 1 bar, and the CO2 gas transmission rate from 147 to 188 (ml/m2 24h 1 bar. The heat seal strength of the PuOC/Zein pouches decreased during the whole storage period. The percentage of O2 in PuOC/Zein pouches increased up to 7 times during the storage period; however, the percentage of CO2 decreased up to 18 times already after one week, and then remained stable in the rest of the storage period. These results are, to a smaller extent, due to the gas transmission rate through the material, especially for CO2 , and to a greater extent, due to the low heat seal strength, which decreased through the storage period, and probably influenced the content of the gases in the pouches.[Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. 46010

  13. Spider Silk: From Protein-Rich Gland Fluids to Diverse Biopolymer Fibers

    Science.gov (United States)

    2016-01-06

    properties from tougher than Kevlar to the extensibility of rubber and have the potential for numerous military applications ranging from high... infrared (FT- Figure 7. 31P DD-MAS and CP-MAS NMR spectra on native, hydrated (A, B), EDTA-treated (C, D) and CaCl2-treated (E, F) caddisfly silk

  14. Processing of Ceramics by Biopolymers. Ultrastructure-Property Relationships in Biocrystals

    Science.gov (United States)

    1991-10-09

    hydroxyapatite mineral as the inorganic phase leading to the formation of bone [1,5,12]. Similar to the role that collagen plays in the formation of bone, a...production of magnetosomes. One of the main objectives in completing Eixp. III wr&as to determine the-2 nurnber of xr ~4,msrelat%*ive to the ia’., in...material in which elongated particles of hydroxyapatite (a calcium compound that is the mineral titania (TiC2) are distributed also the main mineral

  15. Immobilization of inorganic ion-exchanger into bio-polymer foams - Application to cesium sorption

    International Nuclear Information System (INIS)

    Vincent, Chloe; Hertz, Audrey; Barre, Yves; Vincent, Thierry; Guibal, Eric

    2014-01-01

    Nickel-potassium ferrocyanide (along with other ferrocyanide sub-products, as shown by mineralization, SEM-EDX and XRD analyses) has been immobilized in highly porous discs of chitin for the sorption of Cs(I) from near neutral solutions. The immobilization process allows synthesizing stable materials that can bind up to 80 mg Cs g -1 (i.e., 240 mg Cs g -1 ion-exchanger). Cesium sorption is hardly affected by the pH between pH 2 and 8. The sorbent is selective to Cs(I) even in the presence of high concentrations of Na(I), K(I), Rb(I) or NH 4+ . The pseudo-second order rate equation fits well kinetic profiles: the rate coefficient increases with the flow rate of recirculation (to force the access to potentially non-interconnected pores), as an evidence of the control of uptake kinetics by diffusion properties. In fixed-bed columns, the breakthrough curve is accurately described by the Clark model and the sorption capacity (at sorbent saturation) is consistent with the values obtained in sorption isotherms. Preliminary tests performed on 137 Cs spiked solutions confirm the efficiency of the material for the treatment of effluents bearing radionuclides. (authors)

  16. Conductivity studies of biopolymer electrolytes based on chitosan incorporated with NH4Br

    International Nuclear Information System (INIS)

    Shukur, M F; Azmi, M S; Zawawi, S M M; Majid, N A; Illias, H A; Kadir, M F Z

    2013-01-01

    A polymer electrolyte system based on chitosan complexed with ammonium bromide (NH 4 Br) salt was prepared by the solution cast technique. 30 wt% NH 4 Br added electrolyte gave a room temperature conductivity of (4.38 ± 1.26) × 10 −7  S cm −1 and increased to (2.15 ± 0.47) × 10 −4  S cm −1 with addition of 40 wt% glycerol. The dependence of the conductivity on temperature proves that both chitosan–NH 4 Br and chitosan–NH 4 Br–glycerol systems are Arrhenian. The activation energy (E a ) value for 70 wt% chitosan–30 wt% NH 4 Br film is 0.31 eV and the E a value for 42 wt% chitosan–18 wt% NH 4 Br–40 wt% glycerol film is 0.20 eV. The carboxamide band at 1640 cm −1 and the amine band at 1549 cm −1 in the spectrum of pure chitosan film shifted to 1617 and 1516 cm −1 , respectively, in the spectrum of 70 wt% chitosan–30 wt% NH 4 Br film, indicating the occurrence of complexation between polymer and salt. The band at 1024 cm −1 in the pure chitosan film spectrum, which corresponds to the C–O stretching vibration, shifted to lower wavenumbers on addition of salt. A new band appears at 997 cm −1 on addition of 40 wt% glycerol. (paper)

  17. Halloysite nanotubes loaded with peppermint essential oil as filler for functional biopolymer film.

    Science.gov (United States)

    Biddeci, G; Cavallaro, G; Di Blasi, F; Lazzara, G; Massaro, M; Milioto, S; Parisi, F; Riela, S; Spinelli, G

    2016-11-05

    The purpose of this paper is to show how a functional bionanocomposite film with both antioxidant and antimicrobial activities was successfully prepared by the filling of a pectin matrix with modified Halloysite nanotubes (HNT) containing the essential peppermint oil (PO). Firstly, HNT surfaces were functionalized with cucurbit[6]uril (CB[6]) molecules with the aim to enhance the affinity of the nanofiller towards PO, which was estimated by means of HPLC experiments. The HNT/CB[6] hybrid was characterized by several methods (thermogravimetry, FT-IR spectroscopy and scanning electron microscopy) highlighting the influence of the supramolecular interactions on the composition, thermal behavior and morphology of the filler. Then, a pectin+HNT/CB[6] biofilm was prepared by the use of the casting method under specific experimental conditions in order to favor the entrapment of the volatile PO into the nanocomposite structure. Water contact angle measurements, thermogravimetry and tensile tests evidenced the effects of the modified filler on the thermo-mechanical and wettability properties of pectin, which were correlated to the microscopic structure of the biocomposite film. In addition, PO release in food simulant solvent was investigated at different temperatures (4 and 25°C), whereas the antioxidant activity of the nanocomposite film was estimated using the DPPH method. Finally, we studied the in vitro antibacterial activity of the biofilm against Escherichia coli (Gram-negative) and Staphylococcus aureus (Gram-positive), which were isolated by beef and cow milk, respectively. These experiments were carried out at specific temperatures (4, 37 and 65°C) that can be useful for a multi-step food conservation. This paper puts forwards an easy strategy to prepare a functional sustainable edible film with thermo-sensitive antioxidant/antimicrobial activity. Copyright © 2016 Elsevier Ltd. All rights reserved.

  18. A high-capacity carbon prepared from renewable chicken feather biopolymer for supercapacitors

    Science.gov (United States)

    Wang, Qiang; Cao, Qi; Wang, Xianyou; Jing, Bo; Kuang, Hao; Zhou, Ling

    2013-03-01

    Micropopous chicken feather carbon (CFC) severing as electrode materials for the first time is prepared via the activation with KOH agent to different extents. The structure and electrochemical properties of CFC materials are characterized with N2 adsorption/desorption measurements, X-ray diffraction (XRD), transmission electron microscope (TEM), cyclic voltammetry (CV), galvanostatic charge/discharge cycling and electrochemical impedance spectroscopy (EIS). The obtained results show that CFC activated by KOH with KOH/CFC weight ratio of 4/1 (CFCA4) possesses the specific surface area of 1839 m2 g-1, average micropore diameter of 1.863 nm, and exhibits the highest initial specific capacitance of 302 F g-1 at current density of 1 A g-1 in 1 M H2SO4, and that even after 5000 cycles, CFCA4 specific capacitance is still as high as 253 F g-1. Furthermore, CFCA4 also delivers specific capacitance of 181 F g-1 at current density of 5 A g-1 and 168 F g-1 at current density of 10 A g-1. Accordingly, the microporous activated carbon material derived from chicken feather provides favorable prospect in electrode materials application in supercapacitors.

  19. Mefenamic acid conjugates based on a hydrophilic biopolymer hydroxypropylcellulose: novel prodrug design, characterization and thermal analysis

    International Nuclear Information System (INIS)

    Hussain, M.A.; Kausar, R.; Amin, M.

    2015-01-01

    Macromolecular prodrugs (MPDs) of mefenamic acid were designed onto a cellulose ether derivative hydroxypropylcellulose (HPC) as ester conjugates. Fabrication of HPC-mefenamic acid conjugates was achieved by using p-toluenesulfonyl chloride as carboxylic acid (a functional group in drug) activator at 80 degree C for 24 h under nitrogen atmosphere. Reaction was preceded under homogeneous reaction conditions as HPC was dissolved before use in DMAc solvent. Imidazole was used as a base. Easy workup reactions resulted in good yields (55-65%) and degree of substitution (DS) of drug (0.37-0.99) onto HPC. The DS was calculated by acid-base titration after saponification and UV/Vis spectrophotometry after hydrolysis. DS by both of the methods was found in good agreement with each other. Aqueous and organic soluble novel prodrugs of mefenamic acid were purified and characterized by different spectroscopic and thermal analysis techniques. The initial, maximum and final degradation temperatures of HPC, mefenamic acid and HPC-mefenamic acid conjugates were drawn from thermogravimetric (TG) and derivative TG curves and compared to access relative thermal stability. The TG analysis has indicated that samples obtained were thermally more stable especially with increased stability of mefenamic acid in HPC-mefenamic acid conjugates. These novel MPDs of mefenamic acid (i.e., HPC-mefenamic acid conjugates) may have potential applications in pharmaceutically viable drug design due to wide range of solubility and extra thermal stability imparted after MPD formation. (author)

  20. Moisture Absorption Behaviour of Biopolymer Polycapralactone (PCL) / Organo Modified Montmorillonite Clay (OMMT) biocomposite films

    Science.gov (United States)

    Malik, Neetu; Shrivastava, Sharad; Bandhu Ghosh, Subrata

    2018-04-01

    Bio composite materials were fabricated using mixing biodegradable polymer polycaptalactone (PCL) and Organo Modified Montmorillonite Clay (OMMT) through solution casting. Various samples of bio composite films were prepared by varying the OMMT wt% composition by 0.1%, 0.5%, 1% and 1.5%. Thereafter, the density and water absorption of the composites were investigated with respect to immersion time in water. The moisture absorption results show that with an increase in weight percentage (from 0.1 to wt 1.5%) of OMMT within the bio polymer films, the absorption value of bio-nanocomposite films reduced rapidly from 34.4% to 22.3%. The density of hybrid composites also increased with increase in weight percentage of OMMT. The swelling characteristic of PCL increased with increasing % of OMMT clay. These results indicate that the optimized composition of constituents in composite membrane could effectively reduce the anhydrous conditions of bio-composite film.

  1. [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.

  2. Glycobiology in yeast: production of bio-ative biopolymers and small molecules

    Energy Technology Data Exchange (ETDEWEB)

    Scheller, Henrik [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2014-04-30

    The accomplished goals of the CRADA were the establishment of a yeast strain capable of producing levels of vanillin suitable for commercial production and the identification of novel glycosyltransferases to construct the biosynthetic pathway of a gum Arabic-variant in yeast.

  3. Mussel-inspired polydopamine biopolymer decorated with magnetic nanoparticles for multiple pollutants removal

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Shengxiao, E-mail: beijingzsx@163.com [School of Chemistry and Materials Science, Ludong University, Yantai 264025, Shandong Province (China); Zhang, Yuanyuan [School of Chemistry and Materials Science, Ludong University, Yantai 264025, Shandong Province (China); Bi, Guoming [Yantai Enironmental Monitoring Center, Yantai 264025, Shandong Province (China); Liu, Junshen [School of Chemistry and Materials Science, Ludong University, Yantai 264025, Shandong Province (China); Wang, Zhigang [Yantai Enironmental Monitoring Center, Yantai 264025, Shandong Province (China); Xu, Qiang; Xu, Hui; Li, Xiaoyan [School of Chemistry and Materials Science, Ludong University, Yantai 264025, Shandong Province (China)

    2014-04-01

    Highlights: • The Fe{sub 3}O{sub 4}/PDA hybrid material was synthesized and characterized. • The PDA polymer was firstly applied in environmental remediation. • The Fe{sub 3}O{sub 4}/PDA exhibited high adsorption capacity for multiple pollutants. • Removal efficiencies of pollutants with Fe{sub 3}O{sub 4}/PDA were pH dependent. - Abstract: The polydopamine polymer decorated with magnetic nanoparticles (Fe{sub 3}O{sub 4}/PDA) was synthesized and applied for removal of multiple pollutants. The resulted Fe{sub 3}O{sub 4}/PDA was characterized with elemental analysis, thermo-gravimetric analyses, vibrating sample magnetometer, high resolution transmission electron microscope, Fourier transform infrared spectra, and X-ray photoelectron spectroscopy. The self-polymerization of dopamine could be completed within 8 h, and Fe{sub 3}O{sub 4} nanoparticles were embedded into PDA polymer. Superparamagnetism and large saturation magnetization facilitated collection of sorbents with a magnet. Based on the catechol and amine groups, the PDA polymer provided multiple interactions to combine with pollutants. To investigate the adsorption ability of Fe{sub 3}O{sub 4}/PDA, heavy metal ions and dyes were selected as target pollutants. The adsorption of pollutants was pH dependent due to the variation of surface charges at different solution pH. The removal efficiencies of cation pollutants enhanced with solution pH increasing, and that of anion pollutant was just the opposite. Under the optimal solution pH, the maximum adsorption capacity calculated from Langmuir adsorption isotherm for methylene blue, tartrazine, Cu{sup 2+}, Ag{sup +}, and Hg{sup 2+} were 204.1, 100.0, 112.9, 259.1, and 467.3 mg g{sup −1}, respectively. The Fe{sub 3}O{sub 4}/PDA shows great potential for multiple pollutants removal, and this study is the first application of PDA polymer in environmental remediation.

  4. Biopolymers form a gelatinous microlayer at the air-sea interface when Arctic sea ice melts

    OpenAIRE

    Galgani, Luisa; Piontek, Judith; Engel, Anja

    2016-01-01

    The interface layer between ocean and atmosphere is only a couple of micrometers thick but plays a critical role in climate relevant processes, including the air-sea exchange of gas and heat and the emission of primary organic aerosols (POA). Recent findings suggest that low-level cloud formation above the Arctic Ocean may be linked to organic polymers produced by marine microorganisms. Sea ice harbors high amounts of polymeric substances that are produced by cells growing within the sea-ice ...

  5. Biopolymers form a gelatinous microlayer at the air-sea interface when Arctic sea ice melts.

    Science.gov (United States)

    Galgani, Luisa; Piontek, Judith; Engel, Anja

    2016-07-20

    The interface layer between ocean and atmosphere is only a couple of micrometers thick but plays a critical role in climate relevant processes, including the air-sea exchange of gas and heat and the emission of primary organic aerosols (POA). Recent findings suggest that low-level cloud formation above the Arctic Ocean may be linked to organic polymers produced by marine microorganisms. Sea ice harbors high amounts of polymeric substances that are produced by cells growing within the sea-ice brine. Here, we report from a research cruise to the central Arctic Ocean in 2012. Our study shows that microbial polymers accumulate at the air-sea interface when the sea ice melts. Proteinaceous compounds represented the major fraction of polymers supporting the formation of a gelatinous interface microlayer and providing a hitherto unrecognized potential source of marine POA. Our study indicates a novel link between sea ice-ocean and atmosphere that may be sensitive to climate change.

  6. Electrospun fish protein fibers as a biopolymer-based carrier – implications for oral protein delivery

    DEFF Research Database (Denmark)

    Boutrup Stephansen, Karen; García-Díaz, María; Jessen, Flemming

    2014-01-01

    Purpose: Protein-based electrospun fibers have emerged as novel nanostructured materials for tissue engineering and drug delivery due to their unique structural characteristics, biocompatibility and biodegradability. The aim of this study was to explore the use of electrospun fibers based on fish...... sarcoplasmic proteins as an oral delivery platform for biopharmaceuticals, using insulin as a model protein. Methods: Fish sarcoplasmic proteins (FSP) were isolated from fresh cod and electrospun into nanomicrofibers using insulin as a model payload. The morphology of FSP fibers was characterized using...... differentiated Caco-2 cell monolayers was followed by RP-HPLC and ELISA, and the transepithelial electrical resistance (TEER) was measured before and after the experiment. Cell viability was assessed by the MTS/PMS assay. Results: Insulin was encapsulated in the electrospun FSP fibers with high efficiency, high...

  7. Terpene and dextran renewable resources for the synthesis of amphiphilic biopolymers.

    Science.gov (United States)

    Alvès, Marie-Hélène; Sfeir, Huda; Tranchant, Jean-François; Gombart, Emilie; Sagorin, Gilles; Caillol, Sylvain; Billon, Laurent; Save, Maud

    2014-01-13

    The present work shows the synthesis of amphiphilic polymers based on the hydrophilic dextran and the hydrophobic terpenes as renewable resources. The first step concerns the synthesis of functional terpene molecules by thiol-ene addition chemistry involving amino or carboxylic acid thiols and dihydromyrcenol terpene. The terpene-modified polysaccharides were subsequently synthesized by coupling the functional terpenes with dextran. A reductive amination step produced terpene end-modified dextran with 94% of functionalization, while the esterification step produced three terpene-grafted dextrans with a number of terpene units per dextran of 1, 5, and 10. The amphiphilic renewable grafted polymers were tested as emulsifiers for the stabilization of liquid miniemulsion of terpene droplets dispersed in an aqueous phase. The average hydrodynamic diameter of the stable droplets was observed at about 330 nm.

  8. The chemical profile and pharmacodynamic properties of extracellular Wollea saccata biopolymer

    Czech Academy of Sciences Publication Activity Database

    Šutovská, M.; Kočmálová, M.; Pappová, L.; Fraňová, S.; Chyba, A.; Kopecký, Jiří; Lukavský, Jaromír; Cepák, Vladislav; Capek, P.

    2017-01-01

    Roč. 103, OCT 2017 (2017), s. 863-869 ISSN 0141-8130 R&D Projects: GA TA ČR TE01020080 Institutional support: RVO:61388971 ; RVO:67985939 Keywords : Wollea saccata * Extracellular proteoglycan * Pharmacodynamic properties Subject RIV: EE - Microbiology, Virology; EI - Biotechnology ; Bionics (BU-J) OBOR OECD: Microbiology; Bioproducts (products that are manufactured using biological material as feedstock) biomaterials, bioplastics, biofuels, bioderived bulk and fine chemical s, bio-derived novel materials (BU-J) Impact factor: 3.671, year: 2016

  9. Urea potentiometric enzymatic biosensor based on charged biopolymers and electrodeposited polyaniline.

    Science.gov (United States)

    Lakard, Boris; Magnin, Delphine; Deschaume, Olivier; Vanlancker, Guilhem; Glinel, Karine; Demoustier-Champagne, Sophie; Nysten, Bernard; Jonas, Alain M; Bertrand, Patrick; Yunus, Sami

    2011-06-15

    A potentiometric biosensor based on urease was developed for the quantitative determination of urea concentration in aqueous solutions for biomedical applications. The urease was either physisorbed onto an electrodeposited polyaniline film (PANI), or immobilized on a layer-by-layer film (LbL) assembled over the PANI film, that was obtained by the alternate deposition of charged polysaccharides (carboxymethylpullulan (CMP) and chitosan (CHI)). In the latter case, the urease (Urs) enzyme was either physically adsorbed or covalently grafted to the LbL film using carbodiimide coupling reaction. Potentiometric responses of the enzymatic biosensors were measured as a function of the urea concentration in aqueous solutions (from 10(-6) to 10(-1) mol L(-1) urea). Very high sensitivity and short response time were observed for the present biosensor. Moreover, a stability study showed a higher stability over time for the potentiometric response of the sensor with the enzyme-grafted LbL film, testifying for the protective nature of the polysaccharide coating and the interest of covalent grafting. Copyright © 2011 Elsevier B.V. All rights reserved.

  10. In vitro analysis of biopolymer coating with glycidoxypropyltrimethoxysilane on hernia meshes.

    Science.gov (United States)

    Metzler, Steffen; Zankovych, Sergiy; Rauchfuß, Falk; Dittmar, Yves; Jandt, Karin; Jandt, Klaus D; Settmacher, Utz; Scheuerlein, Hubert

    2017-07-01

    Certain coatings may improve the biocompatibility of hernia meshes. The coating with self-assembled monolayers, such as glycidoxypropyltrimethoxysilane (GOPS) can also improve the materials characteristics of implants. This approach was not yet explored in hernia meshes. It was the aim of this work to clarify if and how hernia meshes with their three-dimensional structure can be coated with GOPS and with which technique this coating can be best characterized. Commercially available meshes made from polypropylene (PP), polyester (PE), and expanded polytetrafluorethylene (ePTFE) have been coated with GOPS. The coatings were analyzed via X-ray photoelectron spectroscopy (XPS), confocal laser scanning microscopy (CLSM), and cell proliferation test (mouse fibroblasts). Cell viability and cytotoxicity were tested by MTT test. With the GOPS surface modification, the adherence of mouse fibroblasts on polyester meshes and the proliferation on ePTFE meshes were increased compared to noncoated meshes. Both XPS and CLSM are limited in their applicability and validity due to the three-dimensional mesh structure while CLSM was overall more suitable. In the MTT test, no negative effects of the GOPS coating on the cells were detected after 24 h. The present results show that GOPS coating of hernia meshes is feasible and effective. GOPS coating can be achieved in a fast and cost-efficient way. Further investigations are necessary with respect to coating quality and adverse effects before such a coating may be used in the clinical routine. In conclusion, GOPS is a promising material that warrants further research as coating of medical implants. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 1083-1090, 2017. © 2016 Wiley Periodicals, Inc.

  11. Methanol-induced chain termination in poly(3-hydroxybutyrate) biopolymers: molecular weight control

    Science.gov (United States)

    A systematic study was performed to demonstrate the impact of methanol (MeOH) on poly(3-hydroxybutyrate) (PHB) synthesis and molecular weight (MW) control. Glycerine (init. conc. = 1.0%; w/v), was used as the primary carbon source in batch-culture fermentations with varying concentrations (0 to 0.85...

  12. Biopolymer-nanocarbon composite electrodes for use as high-energy high-power density electrodes

    Science.gov (United States)

    Karakaya, Mehmet; Roberts, Mark; Arcilla-Velez, Margarita; Zhu, Jingyi; Podila, Ramakrishna; Rao, Apparao

    2014-03-01

    Supercapacitors (SCs) address our current energy storage and delivery needs by combining the high power, rapid switching, and exceptional cycle life of a capacitor with the high energy density of a battery. Although activated carbon is extensively used as a supercapacitor electrode due to its inexpensive nature, its low specific capacitance (100-120 F/g) fundamentally limits the energy density of SCs. We demonstrate that a nano-carbon based mechanically robust, electrically conducting, free-standing buckypaper electrode modified with an inexpensive biorenewable polymer, viz., lignin increases the electrode's specific capacitance (~ 600-700 F/g) while maintaining rapid discharge rates. In these systems, the carbon nanomaterials provide the high surface area, electrical conductivity and porosity, while the redox polymers provide a mechanism for charge storage through Faradaic charge transfer. The design of redox polymers and their incorporation into nanomaterial electrodes will be discussed with a focus on enabling high power and high energy density electrodes. Research supported by US NSF CMMI Grant 1246800.

  13. Identification of the mechanical behaviour of biopolymer composites using multistart optimisation technique

    KAUST Repository

    Brahim, Elhacen

    2013-10-01

    This paper aims at identifying the mechanical behaviour of starch-zein composites as a function of zein content using a novel optimisation technique. Starting from bending experiments, force-deflection response is used to derive adequate mechanical parameters representing the elastic-plastic behaviour of the studied material. For such a purpose, a finite element model is developed accounting for a simple hardening rule, namely isotropic hardening model. A deterministic optimisation strategy is implemented to provide rapid matching between parameters of the constitutive law and the observed behaviour. Results are discussed based on the robustness of the numerical approach and predicted tendencies with regards to the role of zein content. © 2013 Elsevier Ltd.

  14. Biopolymer-based degradable nanofibres from renewable resources produced by freeze-drying

    Czech Academy of Sciences Publication Activity Database

    Vetrík, Miroslav; Přádný, Martin; Kobera, Libor; Šlouf, Miroslav; Rabyk, Mariia; Pospíšilová, Aneta; Štěpánek, Petr; Hrubý, Martin

    2013-01-01

    Roč. 3, č. 35 (2013), s. 15282-15289 ISSN 2046-2069 R&D Projects: GA ČR GAP108/10/1560; GA ČR GA202/09/2078 Grant - others:AV ČR(CZ) M200501201 Program:M Institutional support: RVO:61389013 Keywords : glycogen * nanofibres * poly(ethyl cyanoacrylate) Subject RIV: BO - Biophysics Impact factor: 3.708, year: 2013

  15. Bio-orthogonal Fluorescent Labelling of Biopolymers through Inverse-Electron-Demand Diels-Alder Reactions.

    Science.gov (United States)

    Kozma, Eszter; Demeter, Orsolya; Kele, Péter

    2017-03-16

    Bio-orthogonal labelling schemes based on inverse-electron-demand Diels-Alder (IEDDA) cycloaddition have attracted much attention in chemical biology recently. The appealing features of this reaction, such as the fast reaction kinetics, fully bio-orthogonal nature and high selectivity, have helped chemical biologists gain deeper understanding of biochemical processes at the molecular level. Listing the components and discussing the possibilities and limitations of these reagents, we provide a recent snapshot of the field of IEDDA-based biomolecular manipulation with special focus on fluorescent modulation approaches through the use of bio-orthogonalized building blocks. At the end, we discuss challenges that need to be addressed for further developments in order to overcome recent limitations and to enable researchers to answer biomolecular questions in more detail. © 2017 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA.

  16. Shape-Memory Effects in Biopolymer Networks with Collagen-Like Transient Nodes

    NARCIS (Netherlands)

    Skrzeszewska, P.J.; Jong, L.N.; Wolf, de F.A.; Stuart, M.A.C.; Gucht, van der J.

    2011-01-01

    In this article we study shape-memory behavior of hydrogels, formed by biodegradable and biocompatible recombinant telechelic polypeptides, with collagen-like end blocks and a random coil-like middle block. The programmed shape of these hydrogels was achieved by chemical cross-linking of lysine

  17. Dynamics of biopolymers on nanomaterials studied by quasielastic neutron scattering and MD simulations

    Science.gov (United States)

    Dhindsa, Gurpreet K.

    Neutron scattering has been proved to be a powerful tool to study the dynamics of biological systems under various conditions. This thesis intends to utilize neutron scattering techniques, combining with MD simulations, to develop fundamental understanding of several biologically interesting systems. Our systems include a drug delivery system containing Nanodiamonds with nucleic acid (RNA), and two specific model proteins, beta-Casein and Inorganic Pyrophosphatase (IPPase). RNA and nanodiamond (ND) both are suitable for drug-delivery applications in nano-biotechnology. The architecturally flexible RNA with catalytic functionality forms nanocomposites that can treat life-threatening diseases. The non-toxic ND has excellent mechanical and optical properties and functionalizable high surface area, and thus actively considered for biomedical applications. In this thesis, we utilized two tools, quasielastic neutron scattering (QENS) and Molecular Dynamics Simulations to probe the effect of ND on RNA dynamics. Our work provides fundamental understanding of how hydrated RNA motions are affected in the RNA-ND nanocomposites. From the experimental and Molecular Dynamics Simulation (MD), we found that hydrated RNA motion is faster on ND surface than a freestanding one. MD Simulation results showed that the failure of Stokes Einstein relation results the presence of dynamic heterogeneities in the biomacromolecules. Radial pair distribution function from MD Simulation confirmed that the hydrophilic nature of ND attracts more water than RNA results the de-confinement of RNA on ND. Therefore, RNA exhibits faster motion in the presence of ND than freestanding RNA. In the second project, we studied the dynamics of a natively disordered protein beta-Casein which lacks secondary structures. In this study, the temperature and hydration effects on the dynamics of beta-Casein are explored by Quasielastic Neutron Scattering (QENS). We investigated the mean square displacement (MSD) of hydrated and dry beta-Casein as a function of temperature, to study the effect of hydration on their flexibility. The Elastic Incoherent Structure Factor (EISF) in the energy domain reveals the fraction of hydrogen atoms participating in motion in a sphere of diffusion. In the time domain analysis, a logarithmic-like decay is observed in the range of picosecond to nanosecond (beta-relaxation time) in the dynamics of hydrated beta-Casein. Our temperature dependent QENS experiments provide evidence that lack of secondary structure in beta-Casein results in higher flexibility in its dynamics and easier reversible thermal unfolding compared to other rigid biomolecules. Lastly, we studied the domain motion of IPPase protein by Neutron Spin Echo Spectroscopy (NSE). We found that decrease in diffusion coefficient belongs to domain motion of IPPase. Moreover, Rg is varied by temperature and concentration.

  18. Innovative Application of Biopolymer Keratin as a Filler of Synthetic Acrylonitrile-Butadiene Rubber NBR

    OpenAIRE

    Prochoń, Mirosława; Przepiórkowska, Anita

    2013-01-01

    The current investigations show the influence of keratin, recovered from the tanning industry, on the thermal and mechanical properties of vulcanizates with synthetic rubber acrylonitrile-butadiene rubber NBR. The addition of waste protein to NBR vulcanizates influences the improvement of resistance at high temperatures and mechanical properties like tensile strength and hardness. The introduction of keratin to the mixes of rubber previously blended with zinc oxide (ZnO) before vulcanization ...

  19. Innovative Application of Biopolymer Keratin as a Filler of Synthetic Acrylonitrile-Butadiene Rubber NBR

    Directory of Open Access Journals (Sweden)

    Mirosława Prochoń

    2013-01-01

    Full Text Available The current investigations show the influence of keratin, recovered from the tanning industry, on the thermal and mechanical properties of vulcanizates with synthetic rubber acrylonitrile-butadiene rubber NBR. The addition of waste protein to NBR vulcanizates influences the improvement of resistance at high temperatures and mechanical properties like tensile strength and hardness. The introduction of keratin to the mixes of rubber previously blended with zinc oxide (ZnO before vulcanization process leads to an increase in the cross-linking density of vulcanizates. The polymer materials received including addition of proteins will undergo biodecomposition in natural conditions. After soil test, vulcanizates with keratin especially keratin with ZnO showed much more changes on the surface area than vulcanizates without protein. In that aerobic environment, microorganisms, bacteria, and fungus digested better polymer materials containing natural additives.

  20. Radiation Processing of Bio-Polymers for Agriculture Applications. Chapter 21

    Energy Technology Data Exchange (ETDEWEB)

    Quynh, Tran Minh [Hanoi Irradiation Center, Vietnam Atomic Energy Institute (Viet Nam)

    2014-07-15

    Antimicrobial activity of chitosan, a well-known natural polysaccharide has been greatly improved by gamma irradiation. The highest antibacterial activity for E.coli and antifungal activity for Fusarium dimerum Penzig was obtained with chitosan irradiated at about 50–75 kGy. Other chemical properties of chitosan e.g. viscosity, molecular weight, and degree of deacetylation (DD) were also changed by radiation. The number average molecular weight of chitosan significantly reduced from 300 000–100 000 g.mol{sup -1}, whereas its DD slightly increased. A study of the chitosan membrane indicated that radiation treatment strongly influenced its mechanical properties. Both tensile and elongation at break of the irradiated chitosan were reduced with radiation dose. Irradiated chitosan can be applied as a preservative solution for the coating of fresh fruits. Also, antimicrobial packaging films from irradiated chitosan can be produced for ready-to-eat foods. Recent studies on radiation cross-linked cassava starch based hydrogels suggest that superabsorbent materials can absorb not only water but also nutrient solutions containing N, P, and K ions. This can be prepared through gamma radiation using a suitable formulation. Superabsorbent materials, swollen in NPK solution, can be used as slow-release fertilizers and considered as one of the technological advances in agricultural production. (author)

  1. Analysis of Casein Biopolymers Adsorption to Lignocellulosic Biomass as a Potential Cellulase Stabilizer

    Science.gov (United States)

    Eckard, Anahita Dehkhoda; Muthukumarappan, Kasiviswanathan; Gibbons, William

    2012-01-01

    Although lignocellulosic materials have a good potential to substitute current feedstocks used for ethanol production, conversion of these materials to fermentable sugars is still not economical through enzymatic hydrolysis. High cost of cellulase has prompted research to explore techniques that can prevent from enzyme deactivation. Colloidal proteins of casein can form monolayers on hydrophobic surfaces that alleviate the de-activation of protein of interest. Scanning electron microscope (SEM), fourier transform infrared spectroscopy (FT-IR), capillary electrophoresis (CE), and Kjeldahl and BSA protein assays were used to investigate the unknown mechanism of action of induced cellulase activity during hydrolysis of casein-treated biomass. Adsorption of casein to biomass was observed with all of the analytical techniques used and varied depending on the pretreatment techniques of biomass. FT-IR analysis of amides I and II suggested that the substructure of protein from casein or skim milk were deformed at the time of contact with biomass. With no additive, the majority of one of the cellulase mono-component, 97.1 ± 1.1, was adsorbed to CS within 24 h, this adsorption was irreversible and increased by 2% after 72 h. However, biomass treatment with skim-milk and casein reduced the adsorption to 32.9% ± 6.0 and 82.8% ± 6.0, respectively. PMID:23118515

  2. Edible Scaffolds Based on Non-Mammalian Biopolymers for Myoblast Growth

    Directory of Open Access Journals (Sweden)

    Javier Enrione

    2017-12-01

    Full Text Available In vitro meat has recently emerged as a new concept in food biotechnology. Methods to produce in vitro meat generally involve the growth of muscle cells that are cultured on scaffolds using bioreactors. Suitable scaffold design and manufacture are critical to downstream culture and meat production. Most current scaffolds are based on mammalian-derived biomaterials, the use of which is counter to the desire to obviate mammal slaughter in artificial meat production. Consequently, most of the knowledge is related to the design and control of scaffold properties based on these mammalian-sourced materials. To address this, four different scaffold materials were formulated using non-mammalian sources, namely, salmon gelatin, alginate, and additives including gelling agents and plasticizers. The scaffolds were produced using a freeze-drying process, and the physical, mechanical, and biological properties of the scaffolds were evaluated. The most promising scaffolds were produced from salmon gelatin, alginate, agarose, and glycerol, which exhibited relatively large pore sizes (~200 μm diameter and biocompatibility, permitting myoblast cell adhesion (~40% and growth (~24 h duplication time. The biodegradation profiles of the scaffolds were followed, and were observed to be less than 25% after 4 weeks. The scaffolds enabled suitable myogenic response, with high cell proliferation, viability, and adequate cell distribution throughout. This system composed of non-mammalian edible scaffold material and muscle-cells is promising for the production of in vitro meat.

  3. Radiolytic alteration of biopolymers in the Mulga Rock (Australia) uranium deposit

    International Nuclear Information System (INIS)

    Jaraula, Caroline M.B.; Schwark, Lorenz; Moreau, Xavier; Pickel, Walter; Bagas, Leon; Grice, Kliti

    2015-01-01

    Highlights: • Bulk kerogen compositions indicate land plant sources for organic matter in the uranium deposit. • Radiolysis led to cleavage of straight long chain forming medium chain length n-alkyl moieties. • Secondary and tertiary reactions with OH − radicals promoted the formation of alkanones. • “Radiolytic molecular markers” imply molecular markers resulting from radiolytic cracking. • A mechanism is proposed for the production of n-alkanes and n-alkanones. - Abstract: We investigated the effect of ionizing radiation on organic matter (OM) in the carbonaceous uranium (U) mineralization at the Mulga Rock deposit, Western Australia. Samples were collected from mineralized layers between 53 and 58.5 m depths in the Ambassador prospect, containing <5300 ppm U. Uranium bears a close spatial relationship with OM, mostly finely interspersed in the attrinite matrix and via enrichments within liptinitic phytoclasts (mainly sporinite and liptodetrinite). Geochemical analyses were conducted to: (i) identify the natural sources of molecular markers, (ii) recognize relationships between molecular markers and U concentrations and (iii) detect radiolysis effects on molecular marker distributions. Carbon to nitrogen ratios between 82 and 153, and Rock–Eval pyrolysis yields of 316–577 mg hydrocarbon/g TOC (HI) and 70–102 mg CO 2 /g TOC (OI) indicate a predominantly lipid-rich terrigenous plant OM source deposited in a complex shallow swampy wetland or lacustrine environment. Saturated hydrocarbon and ketone fractions reveal molecular distributions co-varying with U concentration. In samples with <1700 ppm U concentrations, long-chain n-alkanes and alkanones (C 27 –C 31 ) reveal an odd/even carbon preference indicative of extant lipids. Samples with ⩾1700 ppm concentrations contain intermediate-length n-alkanes and alkanones, bearing a keto-group in position 2–10, with no carbon number preference. Such changes in molecular distributions are inconsistent with diagenetic degradation of terrigenous OM in oxic depositional environments and cannot be associated with thermal breakdown due to the relatively low thermal maturity of the deposits (R r = 0.26%). It is assumed that the intimate spatial association of high U concentrations resulted in breakdown via radiolytic cracking of recalcitrant polyaliphatic macromolecules (spores, pollen, cuticles, or algal cysts) yielding medium chain length n-alkanes (C 13 –C 24 ). Reactions of n-alkenes with OH − radicals from water hydrolysis produced alcohols that dehydrogenated to alkanones or through carbonylation formed alkanones. Rapid reactions with hydroxyl radicals likely decreased the isomerization of n-alkenes and decreased alkanone diversity, such that the alkan-2-one isomer is predominant. This specific distribution of components generated by natural radiolysis enables their application as “radiolytic molecular markers”. Breaking of C–C bonds through radiolytic cracking at temperatures much lower than the oil window (<50 °C) can have profound implications on initiation of petroleum formation, paleoenvironmental reconstructions, mineral exploration and in tracking radiolysis of OM

  4. Lignin Modification for Biopolymer/Conjugated Polymer Hybrids as Renewable Energy Storage Materials.

    Science.gov (United States)

    Nilsson, Ting Yang; Wagner, Michal; Inganäs, Olle

    2015-12-07

    Lignin derivatives, which arise as waste products from the pulp and paper industry and are mainly used for heating, can be used as charge storage materials. The charge storage function is a result of the quinone groups formed in the lignin derivative. Herein, we modified lignins to enhance the density of such quinone groups by covalently linking monolignols and quinones through phenolation. The extra guaiacyl, syringyl, and hydroquinone groups introduced by phenolation of kraft lignin derivatives were monitored by (31) P nuclear magnetic resonance and size exclusion chromatography. Electropolymerization in ethylene glycol/tetraethylammonium tosylate electrolyte was used to synthesize the kraft lignin/polypyrrole hybrid films. These modifications changed the phenolic content of the kraft lignin with attachment of hydroquinone units yielding the highest specific capacity (around 70 mA h g(-1) ). The modification of softwood and hardwood lignin derivatives yielded 50 % and 23 % higher charge capacity than the original lignin, respectively. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Biopolymer-stabilized Pt nanoparticles colloid: a highly active and recyclable catalyst for biphasic catalysis

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Yujia; Shen, Yueyue; Qiu, Yunfei; Zhang, Ting; Liao, Yang; Zhao, Shilin; Ma, Jun, E-mail: 1044208419@qq.com; Mao, Hui, E-mail: rejoice222@163.com [Sichuan Normal University, College of Chemistry and Materials Science (China)

    2016-10-15

    Noble metal nanoparticles are promising candidates to replace conventional bulk counterparts owing to their high activity and selectivity. To enable catalyst recovery, noble metal nanoparticles are often supported onto solid matrices to prepare heterogeneous catalyst. Although recycle of noble metal nanoparticles is realized by heterogenization, a loss of activity is usually encountered. In the present investigation, Pt nanoparticles with tunable particle size (1.85–2.80 nm) were facilely prepared by using polyphenols as amphiphilic stabilizers. The as-prepared Pt nanoparticles colloid solution could be used as highly active catalyst in aqueous–organic biphasic catalysis. The phenolic hydroxyls of polyphenols could constrain Pt nanoparticles in aqueous phase, and simultaneously, the aromatic scaffold of polyphenols ensured effective interactions between substrates and Pt nanoparticles. As a consequence, the obtained polyphenols-stabilized Pt nanoparticles exhibited high activity and cycling stability in biphasic hydrogenation of a series of unsaturated compounds. Compared with conventional heterogeneous Pt-C and Pt-Al{sub 2}O{sub 3} catalysts, polyphenols-stabilized Pt nanoparticles showed obvious advantage both in activity and cycling stability.

  6. Fungal and Bacterial Infection Mitigation with Antibiotic and Antifungal Loaded Biopolymer Sponges

    Science.gov (United States)

    Parker, Ashley Cox

    Musculoskeletal injuries are some of the most prevalent injuries in both civilian and military populations and their infections can be difficult to treat, often resulting in multiple surgeries and increased costs. In both previous and recent military operations, extremity injuries have been the most common battlefield injuries and many involve complex, open fractures. These extremity injuries are especially susceptible to multiple pathogenic, and sometimes drug resistant, bacteria and fungi. Fungal infections have recently become increasingly problematic in both military and civilian populations and have significantly higher amputation rates than those from bacterial infections. Many of these bacterial and fungal strains adhere to tissue and implanted orthopaedic hardware within wounds, forming biofilms. These problematic, often polymicrobial, infections threaten the health of the patient, but the risk also exists of spreading within hospitals to become prominent resistant infections. Local antimicrobial delivery releases high levels of antimicrobials directly to injured wound tissue, overcoming sub-bactericidal or subfungicidal antimicrobial levels present in the avascular wound zones. This research will determine the ability of modified chitosan sponges, buffered with sodium acetate or blended with polyethylene glycol (PEG), to act as short term adjunctive therapies to initial surgical treatment for delivering both antibiotics and/or antifungals for early abatement of infection. The objective of this work was to evaluate both types of modified sponges for in vitro and in vivo material characteristics and device functionality. In vitro analysis demonstrated both the buffered and PEG modified chitosan sponges exhibited increased degradation and functional cytocompatibility. The chitosan/PEG sponges were able to be loaded with hydrophobic antifungals and the sponges released in vitro biologically active concentrations, alone or in combination with the antibiotic vancomycin. Both types of modified sponges exhibited good biocompatibility and slight, but not complete, degradation in an in vivo rat intramuscular degradation and biocompatibility model. In an in vivo bacteria biofilm infection prevention mouse model, vancomycin loaded chitosan/PEG sponges also cleared more bacteria than the unmodified chitosan sponges. These experimental results led to the conclusion that with additional research and in vivo studies, the buffered and PEG blended chitosan sponge local delivery systems exhibit potential for use as adjunctive bacterial or fungal infection prevention therapies to standard surgical treatment of musculoskeletal wounds.

  7. A spent coffee grounds based biorefinery for the production of biofuels, biopolymers, antioxidants and biocomposites.

    Science.gov (United States)

    Karmee, Sanjib Kumar

    2018-02-01

    Spent coffee grounds are composed of lipid, carbohydrates, carbonaceous, and nitrogen containing compounds among others. Using n-hexane and n-hexane/isopropanol mixture highest oil yield was achived during soxhlet extraction of oil from spent coffee grounds. Alternatively, supercritical carbon dioxide can be employed as a green solvent for the extraction of oil. Using advanced chemical and biotechnological methods, spent coffee grounds are converted to various biofuels such as, biodiesel, renewable diesel, bioethanol, bioethers, bio-oil, biochar, and biogas. The in-situ transesterification of spent coffee grounds was carried out in a large scale (4 kg), which led to 80-83% biodiesel yield. In addition, a large number of value added and diversified products viz. polyhydroxyalkanoates, biosorbent, activated carbon, polyol, polyurethane foam, carotenoid, phenolic antioxidants, and green composite are obtained from spent coffee grounds. The principles of circular economy are applied to develop a sustanaible biorefinery based on valorisation of spent coffee grounds. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Rheological and thermal characteristics of wheat gluten biopolymers plasticized with glycerol

    Directory of Open Access Journals (Sweden)

    Shana Pires Ferreira

    2012-01-01

    Full Text Available The objective this work was to obtain bioplastics from mixtures of wheat gluten and glycerol by two different processes and evaluate their respective rheological properties. The mixtures and their respective bioplastics were obtained through direct batch mixing under approximately adiabatic and isothermal conditions. The bioplastics showed high values for the storage (G' and loss (G" moduli, suggesting a stronger protein network formed in both processes. The temperature onset and the percentage of weight loss to be estimated were found to be near in both bioplastics. The bioplastics have demonstrated to be materials of interesting potential of use as biodegradable barrier materials.

  9. Separation of magnetic affinity biopolymer adsorbents in a Davis tube magnetic separator

    Czech Academy of Sciences Publication Activity Database

    Šafařík, Ivo; Mucha, Pavel; Pechoč, Jiří; Stoklasa, Jaroslav; Šafaříková, Miroslava

    2001-01-01

    Roč. 23, - (2001), s. 851-855 ISSN 0141-5492 R&D Projects: GA ČR GA203/98/1145 Institutional research plan: CEZ:AV0Z6087904 Keywords : Davis tube * magnetic adsorbents * magnetic separation Subject RIV: EI - Biotechnology ; Bionics Impact factor: 0.915, year: 2001

  10. Early stiffening and softening of collagen : interplay of deformation mechanisms in biopolymer networks

    NARCIS (Netherlands)

    Kurniawan, N.A.; Wong, Long Hui; Rajagopalan, Raj

    2012-01-01

    Collagen networks, the main structural/mechanical elements in biological tissues, increasingly serve as biomimetic scaffolds for cell behavioral studies, assays, and tissue engineering, and yet their full spectrum of nonlinear behavior remains unclear. Here, with self-assembled type-I collagen as

  11. The development of biopolymer-based nanostructured materials : plastics, gels, IPNs and nanofoams

    NARCIS (Netherlands)

    Soest, van J.J.G.

    2006-01-01

    The ability to design products with structural features on a nanometric scale is a major technology driver in materials research Nanostructured materials are defined as materials with structural features on a sub-micron scale determining specific properties They consist of materials such as metals,

  12. Thermophilic and thermoacidophilic biopolymer-degrading genes and enzymes from Alicyclobacillus acidocaldarius and related organisms, methods

    Energy Technology Data Exchange (ETDEWEB)

    Thompson, David N.; Apel, William A.; Thompson, Vicki S.; Reed, David W.; Lacey, Jeffrey A.; Henriksen, Emily D.

    2018-02-20

    Isolated and/or purified polypeptides and nucleic acid sequences encoding polypeptides from Alicyclobacillus acidocaldarius are provided. Further provided are methods of at least partially degrading, cleaving, or removing polysaccharides, lignocellulose, cellulose, hemicellulose, lignin, starch, chitin, polyhydroxybutyrate, heteroxylans, glycosides, xylan-, glucan-, galactan-, or mannan-decorating groups using isolated and/or purified polypeptides and nucleic acid sequences encoding polypeptides from Alicyclobacillus acidocaldarius.

  13. Rigid Biopolymer Nanocrystal Systems for Controlling Multicomponent Nanoparticle Assembly and Orientation in Thin Film Solar Cells

    Energy Technology Data Exchange (ETDEWEB)

    Cha, Jennifer [Univ. of Colorado, Boulder, CO (United States)

    2016-10-31

    We have discovered techniques to synthesize well-defined DN conjugated nanostructures that are stable in a wide variety of conditions needed for DNA mediated assembly. Starting from this, we have shown that DNA can be used to control the assembly and integration of semiconductor nanocrystals into thin film devices that show photovoltaic effects.

  14. Analysis of casein biopolymers adsorption to lignocellulosic biomass as a potential cellulase stabilizer.

    Science.gov (United States)

    Eckard, Anahita Dehkhoda; Muthukumarappan, Kasiviswanathan; Gibbons, William

    2012-01-01

    Although lignocellulosic materials have a good potential to substitute current feedstocks used for ethanol production, conversion of these materials to fermentable sugars is still not economical through enzymatic hydrolysis. High cost of cellulase has prompted research to explore techniques that can prevent from enzyme deactivation. Colloidal proteins of casein can form monolayers on hydrophobic surfaces that alleviate the de-activation of protein of interest. Scanning electron microscope (SEM), fourier transform infrared spectroscopy (FT-IR), capillary electrophoresis (CE), and Kjeldahl and BSA protein assays were used to investigate the unknown mechanism of action of induced cellulase activity during hydrolysis of casein-treated biomass. Adsorption of casein to biomass was observed with all of the analytical techniques used and varied depending on the pretreatment techniques of biomass. FT-IR analysis of amides I and II suggested that the substructure of protein from casein or skim milk were deformed at the time of contact with biomass. With no additive, the majority of one of the cellulase mono-component, 97.1 ± 1.1, was adsorbed to CS within 24 h, this adsorption was irreversible and increased by 2% after 72 h. However, biomass treatment with skim-milk and casein reduced the adsorption to 32.9% ± 6.0 and 82.8% ± 6.0, respectively.

  15. Analysis of Casein Biopolymers Adsorption to Lignocellulosic Biomass as a Potential Cellulase Stabilizer

    Directory of Open Access Journals (Sweden)

    Anahita Dehkhoda Eckard

    2012-01-01

    Full Text Available Although lignocellulosic materials have a good potential to substitute current feedstocks used for ethanol production, conversion of these materials to fermentable sugars is still not economical through enzymatic hydrolysis. High cost of cellulase has prompted research to explore techniques that can prevent from enzyme deactivation. Colloidal proteins of casein can form monolayers on hydrophobic surfaces that alleviate the de-activation of protein of interest. Scanning electron microscope (SEM, fourier transform infrared spectroscopy (FT-IR, capillary electrophoresis (CE, and Kjeldahl and BSA protein assays were used to investigate the unknown mechanism of action of induced cellulase activity during hydrolysis of casein-treated biomass. Adsorption of casein to biomass was observed with all of the analytical techniques used and varied depending on the pretreatment techniques of biomass. FT-IR analysis of amides I and II suggested that the substructure of protein from casein or skim milk were deformed at the time of contact with biomass. With no additive, the majority of one of the cellulase mono-component, 97.1 ± 1.1, was adsorbed to CS within 24 h, this adsorption was irreversible and increased by 2% after 72 h. However, biomass treatment with skim-milk and casein reduced the adsorption to 32.9% ± 6.0 and 82.8% ± 6.0, respectively.

  16. Lactic acid production by irradiated Bacillus NF17 and poly-L-lactate biopolymer formation

    International Nuclear Information System (INIS)

    Tongpim, Saowanit; Poonsawat, Choosak; Khansawai, Paveena; Piadaeng, Nattaya

    2006-09-01

    This study was conducted to manipulate the thermo tolerant, lactic acid-producing bacteria, Bacillus coagulans strain NF 1 7, in the production of L-lactic acid and a bio polymer: poly-L-lactate. The bacterial isolate NF 1 7 kept in the culture collection of Khon Kaen University and could tolerate high temperature and produce lactic acid, was employed in this research work. Cell suspension of isolate NF 1 7 was exposed to gamma irradiation at various doses (1-5 KGy). The irradiated survivors were screened on the basis of forming larger colonies and clear zones than the parent strain NF 1 7 when grown on Glucose-Yeast extract-Peptone (GYP) containing CaCO 3 . We obtained 55 effective isolates which the isolate L5I2-14(5), designated as K 1 4, was chosen together with the parent strain NF 1 7 for fermentation experiments. Each bacterial strain was inoculated into GYP broth and incubated statically at 50 o C with daily pH neutralization. After 5 days of incubation, the isolate K 1 4 and NF 1 7 produced 9.71 g/l and 7.42 g/l of L-lactic acid, respectively with a small amount of D-lactic acid. Lactic acid production from sugar cane molasses by batch fermentation of Bacillus Sp. K 1 4 was carried out in a 7 l jar fermentor containing 5 l of fermentation medium. It was found that 20% molasses with the agitation speed of 100 rpm gave the highest yield of lactic acid. Poly-L-lactic acid was chemically polymerized by bulk polymerization process at 140 o C under 40 mmHg conditions. We could obtain the off-white polymer in a small amount of powder form. Improvement the yield of poly-L-lactic acid would be achieved by using polyisoprene-g-polyvinyl monomer to separate lactic acid from the fermenting liquid prior to polymerization processes

  17. The Production, Purification and Properties of the Biopolymer Levan Produced by the Bacterium Erwinia Herbicola

    Science.gov (United States)

    1989-08-01

    after comparison with ATCC 11142 Acetobacter pasteurianus. ATCC 15953 Microbacterium 2 laevanlformans. and QMB 1624 Bacillus coagulans (B, gub^jlu...is produced by several bacteria, including Brwjnja herbicola. Streptococcus salivarius. Pseudomonas prunicola. Bacillus subtilis. and Actinomvcetes...J, i X I i rtfi ii i IT PTT-n T~^L^^^^ r1 •» ■ ■ 11 ■ ■ ■ i >■ 111 I’I I’.VIT fi-H-rtfi 1 -f ’ •■» i | i r , , , Levan from Bacillus

  18. Engineering soil organic matter quality: Biodiesel Co-Product (BCP) stimulates exudation of nitrogenous microbial biopolymers

    Science.gov (United States)

    Redmile-Gordon, Marc A.; Evershed, Richard P.; Kuhl, Alison; Armenise, Elena; White, Rodger P.; Hirsch, Penny R.; Goulding, Keith W.T.; Brookes, Philip C.

    2015-01-01

    Biodiesel Co-Product (BCP) is a complex organic material formed during the transesterification of lipids. We investigated the effect of BCP on the extracellular microbial matrix or ‘extracellular polymeric substance’ (EPS) in soil which is suspected to be a highly influential fraction of soil organic matter (SOM). It was hypothesised that more N would be transferred to EPS in soil given BCP compared to soil given glycerol. An arable soil was amended with BCP produced from either 1) waste vegetable oils or 2) pure oilseed rape oil, and compared with soil amended with 99% pure glycerol; all were provided with 15N labelled KNO3. We compared transfer of microbially assimilated 15N into the extracellular amino acid pool, and measured concomitant production of exopolysaccharide. Following incubation, the 15N enrichment of total hydrolysable amino acids (THAAs) indicated that intracellular anabolic products had incorporated the labelled N primarily as glutamine and glutamate. A greater proportion of the amino acids in EPS were found to contain 15N than those in the THAA pool, indicating that the increase in EPS was comprised of bioproducts synthesised de novo. Moreover, BCP had increased the EPS production efficiency of the soil microbial community (μg EPS per unit ATP) up to approximately double that of glycerol, and caused transfer of 21% more 15N from soil solution into EPS-amino acids. Given the suspected value of EPS in agricultural soils, the use of BCP to stimulate exudation is an interesting tool to consider in the theme of delivering sustainable intensification. PMID:26635420

  19. Effect of gamma irradiation on biopolymer composite films of poly(vinyl alcohol) and bacterial cellulose

    Energy Technology Data Exchange (ETDEWEB)

    Jipa, Iuliana Mihaela; Stroescu, Marta [University Politehnica of Bucharest, Department of Chemical Engineering, 313 Splaiul Independentei, Polizu 1-3, 060042 Bucharest (Romania); Stoica-Guzun, Anicuta, E-mail: stoica.anicuta@gmail.com [University Politehnica of Bucharest, Department of Chemical Engineering, 313 Splaiul Independentei, Polizu 1-3, 060042 Bucharest (Romania); Dobre, Tanase; Jinga, Sorin [University Politehnica of Bucharest, Department of Chemical Engineering, 313 Splaiul Independentei, Polizu 1-3, 060042 Bucharest (Romania); Zaharescu, Traian [Advanced Research Institute for Electrical Engineering, 313 Splaiul Unirii, 030138 Bucharest (Romania)

    2012-05-01

    Highlights: Black-Right-Pointing-Pointer The paper reports the obtaining of composite materials between PVA and BC. Black-Right-Pointing-Pointer The composite films were {gamma}-irradiated at doses up to 50 kGy. Black-Right-Pointing-Pointer The films have a good resistance, being suitable as food packaging materials. - Abstract: Composite materials containing in different ratios poly(vinyl alcohol) (PVA), bacterial cellulose (BC) and glycerol (G) as plasticizer were obtained and exposed to different {gamma} radiation doses using an irradiator GAMMATOR provided with {sup 137}Cs source. These films successively received up to 50 kGy absorbed doses at a dose rate of 0.4 kGy/h at room temperature. In order to study the chemical and structural changes during {gamma} irradiation, Fourier-transformed infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and UV-Vis spectroscopy were used. Water vapour permeability (WVP), Hunter colour parameters and hardness were also measured for the irradiated samples. Investigation revealed that WVP was not significantly affected by the irradiation. Colour measurements indicated a slight decrease of pure PVA films transparency and it made clear that all samples became more reddish and yellowish after irradiation. The samples hardness was not affected by the irradiation doses used. However, the results showed no drastic structural or chemical changes of the irradiated samples, which prove, in consequence, a good durability. These composite materials could be used as packaging materials for {gamma} irradiated products.

  20. Thermophilic and thermoacidophilic biopolymer-degrading genes and enzymes from alicyclobacillus acidocaldarius and related organisms, methods

    Science.gov (United States)

    Thompson, David N.; Apel, William A.; Thompson, Vicki S.; Reed, David W.; Lacey, Jeffrey A.; Henriksen, Emily D.

    2010-12-28

    Isolated and/or purified polypeptides and nucleic acid sequences encoding polypeptides from Alicyclobacillus acidocaldarius are provided. Further provided are methods of at least partially degrading, cleaving, or removing polysaccharides, lignocellulose, cellulose, hemicellulose, lignin, starch, chitin, polyhydroxybutyrate, heteroxylans, glycosides, xylan-, glucan-, galactan, or mannan-decorating groups using isolated and/or purified polypeptides and nucleic acid sequences encoding polypeptides from Alicyclobacillus acidocaldarius.

  1. Thermophilic and thermoacidophilic biopolymer degrading genes and enzymes from Alicyclobacillus acidocaldarius and related organisms, methods

    Science.gov (United States)

    Thompson, David N; Apel, William A; Thompson, Vicki S; Reed, David W; Lacey, Jeffrey A; Henriksen, Emily D.

    2016-08-02

    Isolated and/or purified polypeptides and nucleic acid sequences encoding polypeptides from Alicyclobacillus acidocaldarius are provided. Further provided are methods of at least partially degrading, cleaving, or removing polysaccharides, lignocellulose, cellulose, hemicellulose, lignin, starch, chitin, polyhydroxybutyrate, heteroxylans, glycosides, xylan-, glucan-, galactan-, or mannan-decorating groups using isolated and/or purified polypeptides and nucleic acid sequences encoding polypeptides from Alicyclobacillus acidocaldarius.

  2. Surface-active biopolymers from marine bacteria for potential biotechnological applications

    Directory of Open Access Journals (Sweden)

    Karina Sałek

    2016-03-01

    Full Text Available Surface-active agents are amphiphilic chemicals that are used in almost every sector of modern industry, the bulk of which are produced by organo-chemical synthesis. Those produced from biological sources (biosurfactants and bioemulsifiers, however, have gained increasing interest in recent years due to their wide structural and functional diversity, lower toxicities and high biodegradability, compared to their chemically-synthesised counterparts. This review aims to present a general overview on surface-active agents, including their classification, where new types of these biomolecules may lay awaiting discovery, and some of the main bottlenecks for their industrial-scale production. In particular, the marine environment is highlighted as a largely untapped source for discovering new types of surface-active agents. Marine bacteria, especially those living associated with micro-algae (eukaryotic phytoplankton, are a highly promising source of polymeric surface-active agents with potential biotechnological applications. The high uronic acids content of these macromolecules has been linked to conferring them with amphiphilic qualities, and their high structural diversity and polyanionic nature endows them with the potential to exhibit a wide range of functional diversity. Production yields (e.g. by fermentation for most microbial surface-active agents have often been too low to meet the volume demands of industry, and this principally remains as the most important bottleneck for their further commercial development. However, new developments in recombinant and synthetic biology approaches can offer significant promise to alleviate this bottleneck. This review highlights a particular biotope in the marine environment that offers promise for discovering novel surface-active biomolecules, and gives a general overview on specific areas that researchers and the industry could focus work towards increasing the production yields of microbial surface-active agents.

  3. Biotechnological opportunities to biopolymers production. Oportunidades biotecnologicas para la produccion de biopolimeros

    Energy Technology Data Exchange (ETDEWEB)

    Ballesteros, M; Ballesteros, I; Oliva, J M [Instituto de Energias Renovables, CIEMAT, Madrid (Spain)

    1994-01-01

    The increasing garbage mountain is more and more recognized as an ecological threat, Space for landfills is limited and additional Incineration capacities require high capital investments and pose additional environmental problems. This paper discusses the current development and utilization state of new biodegradable polymers. Special attention is focused on microbiological production of poli-D-Beta-hydroxybutyrate acid (PHB), reviewing the metabolic regulation of PHB and the elements to determine its industrial scale production. (Author) 6 refs.

  4. Signal Propagation and Detection via Catalytically Immolative Biopolymer-Programmed Nanomaterials

    Science.gov (United States)

    2015-02-09

    first time, the use of in situ TEM to characterize soft materials. This technique has been available for some time, but only in recent years has the... diagnostics Eric Tatro (UCSD) –Nucleic acids stabilized in nanostructures for retaining biological function, including gene delivery applications of...Sickle-­‐Cell   Anemia .   Science   230,   1350-­‐ 1354  (1985).   21   Orum,   H.   et   al.   Single-­‐Base   Pair  Mutation

  5. Economic assessment of flash co-pyrolysis of short rotation coppice and biopolymer waste streams

    OpenAIRE

    KUPPENS, Tom; CORNELISSEN, Tom; CARLEER, Robert; YPERMAN, Jan; SCHREURS, Sonja; JANS, Maarten; THEWYS, Theo

    2010-01-01

    The disposal problem associated with phytoextraction of farmland polluted with heavy metals by means of willow requires a biomass conversion technique which meets both ecological and economical needs. Combustion and gasification of willow require special and costly flue gas treatment to avoid re-emission of the metals in the atmosphere, whereas flash pyrolysis mainly results in the production of (almost) metal free bio-oil with a relatively high water content. Flash co-pyrolysis of biomass an...

  6. Optimization of Biopolymer Based Transdermal Films of Metoclopramide as an Alternative Delivery Approach

    Directory of Open Access Journals (Sweden)

    Betül Aktar

    2014-05-01

    Full Text Available The objectives of this study were to develop and to characterize sodium alginate based matrix-type transdermal films of metoclopramide hydrochloride (MTC in order to improve patient compliance to treatment. The suitability of sodium alginate was shown to be a natural film former in terms of the physicochemical, mechanical, and bioadhesive features of the MTC loaded transdermal films. Terpinolene provided the highest drug release among the different terpenes (nerolidol, eucalyptol, dl-limonene, or terpinolene assessed as enhancer. Attenuated Total Reflectance Infrared (ATR-FTIR spectroscopy analysis performed to evaluate the effect of the transdermal films on skin barrier confirmed enhancer induced lipid bilayer disruption in stratum corneum, indicating its permeation enhancement effect.

  7. Improving the quality of biopolymer (poly lactic acid) with the addition of bentonite as filler

    Science.gov (United States)

    Suryani; Agusnar, Harry; Wirjosentono, Basuki; Rihayat, Teuku; Nurhanifa

    2017-07-01

    PLA (Poly Lactid Acid) - Bentonite polymer nanocomposite which is a combination of natural and nanometer-scale inorganic substances created through three processes, mixing using a melt blending, molding with a hot press using specimens Standard ASTM D 638 Type IV and drying. In this study, PLA combined with two types of natural bentonite obtained from different areas to find differences in the quality of the results of characterization. To optimize the performance of filler, before mixing, bentonite have to furificate first with (NaPO3)6 and also open the interlayer space with CTAB. D-spacing of bentonite imterlayer were analyze by X-Ray difraction (XRD). Characterization bionanocomposite resulting morphologic structure was tested using a Transmission Electron Microscope (TEM). Mechanical analysis of PLA-bentonite nanocomposite in the form of tensile strength was tested using a tensile test specimens of standard American Standard for Testing Materials (ASTM) D 638 Type 4, and thermal resistance using Thermo Gravimetric Analysis (TGA).

  8. Characterization of origami shape memory metamaterials (SMMM) made of bio-polymer blends

    Science.gov (United States)

    Kshad, Mohamed Ali E.; Naguib, Hani E.

    2016-04-01

    Shape memory materials (SMMs) are materials that can return to their virgin state and release mechanically induced strains by external stimuli. Shape memory polymers (SMPs) are a class of SMMs that show a high shape recoverability and which have attractive potential for structural applications. In this paper, we experimentally study the shape memory effect of origami based metamaterials. The main focus is on the Muira origami metamaterials. The fabrication technique used to produce origami structure is direct molding where all the geometrical features are molded from thermally virgin polymers without post folding of flat sheets. The study shows experimental investigations of shape memory metamaterials (SMMMs) made of SMPs that can be used in different applications such as medicine, robotics, and lightweight structures. The origami structure made from SMP blends, activated with uniform heating. The effect of blend composition on the shape memory behavior was studied. Also the influence of the thermomechanical and the viscoelastic properties of origami unit cell on the activation process have been discussed, and stress relaxation and shape recovery were investigated. Activation process of the unit cell has been demonstrated.

  9. Silver nanoparticles incorporated into nanostructured biopolymer membranes produced by electrospinning: a study of antimicrobial activity

    Directory of Open Access Journals (Sweden)

    Karen Segala

    2015-12-01

    Full Text Available abstract This study examines the antimicrobial activity of silver nanoparticles incorporated into nanostructured membranes made of cellulose acetate (CA and blends of chitosan/poly-(ethylene oxide, CTS/PEO and prepared by electrospinning. The formation of chemically synthesized Ag nanoparticles (AgNPs was monitored by UV-visible spectroscopy (UV-Vis and characterized by transmission electron microscopy (TEM. The size distribution of the AgNPs was measured by dynamic light scattering (DLS, with an average size of approximately 20 nm. The presence of AgNPs on the surface of electrospun nanofibers was observed by field emission electron microscopy (FEG and confirmed by TEM. The antimicrobial activity of AgNPs incorporated into nanostructured membranes made of CA and CTS/PEO electrospun nanofibers was evaluated in the presence of both Gram-positive bacteria, such as Staphylococcus aureus ATCC 29213 and Propionibacterium acnes ATCC 6919, and Gram-negative bacteria, such as Escherichia coli ATCC 25992 and Pseudomonas aeruginosa ATCC 17933. Microbiological results showed that the presence of AgNPs in CA and CTS/PEO nanostructured membranes has significant antimicrobial activity for the Gram-positive bacteria Escherichia coli and Propionibacterium acnes.

  10. Antimicrobial cerium ion-chitosan crosslinked alginate biopolymer films: A novel and potential wound dressing.

    Science.gov (United States)

    Kaygusuz, Hakan; Torlak, Emrah; Akın-Evingür, Gülşen; Özen, İlhan; von Klitzing, Regine; Erim, F Bedia

    2017-12-01

    Wound dressings require good antiseptic properties, mechanical strength and, more trustably, natural material ingredients. Antimicrobial properties of cerium ions and chitosan are known and alginate based wound dressings are commercially available. In this study, the advantages of these materials were combined and alginate films were crosslinked with cerium(III) solution and chitosan added cerium(III) solution. Films were characterized by Fourier transform infrared spectroscopy (FTIR), light transmittance, scanning electron microscopy (SEM), swelling experiments, water vapor transmittance tests, and mechanical stretching tests. The antibacterial and physical properties of the films were compared with those of conventional calcium alginate films. Both cerium ion crosslinked and cerium ion-chitosan crosslinked alginate films gained antibacterial activity against Gram-negative (Escherichia coli) and Gram-positive (Staphylococcus aureus) bacteria. Cerium alginate-chitosan films showed high resistance to being deformed elastically. Results show that cerium alginate-chitosan films can be flexible, ultraviolet-protecting, and antibacterial wound dressings. Copyright © 2017 Elsevier B.V. All rights reserved.

  11. Nature's amazing biopolymer: basic mechanical and hydrological properties of soil affected by plant exudates

    Science.gov (United States)

    Naveed, Muhammad; Roose, Tiina; Raffan, Annette; George, Timothy; Bengough, Glyn; Brown, Lawrie; Keyes, Sam; Daly, Keith; Hallett, Paul

    2016-04-01

    Plant exudates are known to have a very large impact on soil physical properties through changes in mechanical and hydrological processes driven by long-chain polysaccharides and surface active compounds. Whilst these impacts are well known, the basic physical properties of these exudates have only been reported in a small number of studies. We present data for exudates obtained from barley roots and chia seeds, incorporating treatments examining biological decomposition of the exudates. When these exudates were added to a sandy loam soil, contact angle and drop penetration time increased exponentially with increasing exudate concentration. These wetting properties were strongly correlated with both exudate density and zero-shear viscosity, but not with exudate surface tension. Water holding capacity and water repellency of exudate mixed soil tremendously increased with exudate concentration, however they were significantly reduced on decomposition when measured after 14 days of incubation at 16C. Mechanical stability greatly increased with increasing exudate amendment to soils, which was assessed using a rheological amplitude sweep test near saturation, at -50 cm matric potential (field capacity) using indentation test, and at air-dry condition using the Brazilian test. This reflects that exudates not only attenuate plant water stress but also impart mechanical stability to the rhizosphere. These data are highly relevant to the understanding and modelling of rhizosphere development, which is the next phase of our research.

  12. The generalized model of polypeptide chain describing the helix-coil transition in biopolymers

    International Nuclear Information System (INIS)

    Mamasakhlisov, E.S.; Badasyan, A.V.; Tsarukyan, A.V.; Grigoryan, A.V.; Morozov, V.F.

    2005-07-01

    In this paper we summarize some results of our theoretical investigations of helix-coil transition both in single-strand (polypeptides) and two-strand (polynucleotides) macromolecules. The Hamiltonian of the Generalized Model of Polypeptide Chain (GMPC) is introduced to describe the system in which the conformations are correlated over some dimensional range Δ (it equals 3 for polypeptide, because one H-bond fixes three pairs of rotation, for double strand DNA it equals to one chain rigidity because of impossibility of loop formation on the scale less than Δ). The Hamiltonian does not contain any parameter designed especially for helix-coil transition and uses pure molecular microscopic parameters (the energy of hydrogen bond formation, reduced partition function of repeated unit, the number of repeated units fixed by one hydrogen bond, the energies of interaction between the repeated units and the solvent molecules). To calculate averages we evaluate the partition function using the transfer-matrix approach. The GMPC allowed to describe the influence of a number of factors, affecting the transition, basing on a unified microscopic approach. Thus we obtained, that solvents change transition temperature and interval in different ways, depending on type of solvent and on energy of solvent- macromolecule interaction; stacking on the background of H-bonding increases stability and decreases cooperativity of melting. For heterogeneous DNA we could analytically derive well known formulae for transition temperature and interval. In the framework of GMPC we calculate and show the difference of two order parameters of helix-coil transition - the helicity degree, and the average fraction of repeated units in helical conformation. Given article has the aim to review the results obtained during twenty years in the context of GMPC. (author)

  13. Study on the mechanism of toxicity development by analysis of interactions among RI-labelled biopolymers

    International Nuclear Information System (INIS)

    Koizumi, Shinji

    1997-01-01

    In order to find the directly targetting molecule(s) of toxic substances which are produced in various working environments and to elucidate the natural functions of such molecules in the body. The interactions between an assumed target molecule, ZRF and a sequence in metallothionein II A gene, MRE were investigated using electrophoresis. When double stranded DNA of which binding region was labelled with 32 P was mixed with ZRF, any DNA-protein complex was not detectable on denatured polyacrylamide gel electrophoresis, but Zn-dependent complex formation was observed when labelled in the presence of BrdUTP and the specific band disappeared after the treatment with nuclease. And UV radiation was essential for the complex formation under the conditions of denatured gel, however the complex formed by un-denatured gel electrophoresis was markedly reduced by UV radiation, indicating that the cross-linking reaction should be done at a low dose of UV. Since the nuclease preparation used was contaminated with protease, it was needed to choose an appropriate amount of the preparation. Although there remain some problems, it was found that the present procedure by SDS-polyacrylamide gel electrophoresis was available for detection of the cross-linking between DNA and protein. (M.N.)

  14. Extraction and characterization of gelatin biopolymer from black tilapia (Oreochromis mossambicus) scales

    Science.gov (United States)

    Sockalingam, K.; Abdullah, H. Z.

    2015-07-01

    Black tilapia (Oreochromis mossambicus) fish wastes (scales) were evaluated for its suitability as sources of gelatin. Scales were subjected to acid treatment for demineralization before it undergoes thermal extraction process. The raw scales were characterized via Scanning Electron Microscopy (SEM), which demarcated the cycloid pattern of the scales. SEM images also reveal the presence of collagen fiber in the fish scale. The black tilapia fish scales yields 11.88 % of gelatin, indicating the possibility of this fish species as sources of gelatin. Further characterizations were done on both raw scale and extracted gelatin through Fourier Transform Infrared Spectroscopy (FTIR) and proximate analysis. The scale gelatin shows high protein content (86.9 %) with low moisture (8.2 %) and ash (1.4 %). This further proves the effectiveness of the demineralization and extraction method used. The black tilapia fish scale is found to be a prospective source of gelatin with good chemical and functional properties.

  15. Extraction of high value added gelatin biopolymer from black tilapia (Oreochromis mossambicus) head bones

    Science.gov (United States)

    Sockalingam, K.; Abdullah, H. Z.

    2015-07-01

    Black tilapia (Oreochromis mossambicus) fish head bones were evaluated for its possibilities in extracting gelatin. Head bones were subjected to pre-treatment with 3% of hydrochloric acid (HCl) for demineralization before undergoes thermal extraction process. The raw head bones were characterized via Scanning Electron Microscopy (SEM) in order to investigate the external and internal surface morphology. SEM images also reveal the presence of collagen fiber with 1 µm diameter in the head bone. The black tilapia fish head bones yields 5.75 % of gelatin in wet weight basis, indicating the possibility of this fish species as sources of gelatin. Further characterizations were done on both raw head bones and extracted gelatin through Fourier Transform Infrared Spectroscopy (FTIR) and proximate analysis. The head bones gelatin shows high protein (10.55%) and ash (3.11 %) content with low moisture. This further proves the effectiveness of demineralization and extraction method used. The black tilapia fish head bones are found to be a prospective source of gelatin with good chemical and functional properties.

  16. Extraction of high value added gelatin biopolymer from black tilapia (Oreochromis mossambicus) head bones

    International Nuclear Information System (INIS)

    Sockalingam, K.; Abdullah, H. Z.

    2015-01-01

    Black tilapia (Oreochromis mossambicus) fish head bones were evaluated for its possibilities in extracting gelatin. Head bones were subjected to pre-treatment with 3% of hydrochloric acid (HCl) for demineralization before undergoes thermal extraction process. The raw head bones were characterized via Scanning Electron Microscopy (SEM) in order to investigate the external and internal surface morphology. SEM images also reveal the presence of collagen fiber with 1 µm diameter in the head bone. The black tilapia fish head bones yields 5.75 % of gelatin in wet weight basis, indicating the possibility of this fish species as sources of gelatin. Further characterizations were done on both raw head bones and extracted gelatin through Fourier Transform Infrared Spectroscopy (FTIR) and proximate analysis. The head bones gelatin shows high protein (10.55%) and ash (3.11 %) content with low moisture. This further proves the effectiveness of demineralization and extraction method used. The black tilapia fish head bones are found to be a prospective source of gelatin with good chemical and functional properties

  17. Using complexation for the microencapsulation of nisin in biopolymer matrices by spray-drying.

    Science.gov (United States)

    Ben Amara, Chedia; Kim, Lanhee; Oulahal, Nadia; Degraeve, Pascal; Gharsallaoui, Adem

    2017-12-01

    The aim of this study is to investigate the potential of complexation to encapsulate nisin (5g/L concentration) using spray-drying technique and to evaluate how complexation with pectin or alginate (2g/L concentration) can preserve nisin structure and antimicrobial activity. Spray-drying of nisin-low methoxyl pectin or nisin-alginate electrostatic complexes has led to the microencapsulation of the peptide in different networks that were highly influenced by the polysaccharide type. Turbidity and particle size measurements indicated that while spray-drying promoted the aggregation of nisin-pectin complexes, it favored the dissociation of nisin-alginate aggregates to form individual complexes. Structural changes of nisin induced by complexation with pectin or alginate and spray-drying were studied by using UV-Vis absorption and fluorescence spectroscopy. The results showed that complexation with pectin or alginate preserved nisin structure as well as its antimicrobial activity during spray-drying. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Physiological Requirements for the Production of the Biopolymer Elsinan by Species of Elsinoe

    Science.gov (United States)

    1989-06-01

    fawettii Jenkins (ATCC 36954 and ATOC 38162), E. tilie Creelman (AIM 24510) were chosen for further study, based on product yield and MW, when ccmpared...Elsinoe tiliae Creelman AIC 24510 *Cultures are available from the American Type Culture Collection (ATCC) 12301 Parklawn Drive, Rockville, MD 20852

  19. Osmium tetroxide complexes as versatile tools for structure probing and electrochemical analysis of biopolymers

    Czech Academy of Sciences Publication Activity Database

    Fojta, Miroslav; Kostečka, Pavel; Pivoňková, Hana; Horáková Brázdilová, Petra; Havran, Luděk

    2011-01-01

    Roč. 7, č. 1 (2011), s. 35-50 ISSN 1573-4110 R&D Projects: GA AV ČR(CZ) IAA400040901; GA AV ČR(CZ) IAA400040903; GA ČR(CZ) GP203/08/P598; GA MŠk(CZ) LC06035 Institutional research plan: CEZ:AV0Z50040507; CEZ:AV0Z50040702 Keywords : osmium complexes * DNA labelling * electrochemical analysis Subject RIV: BO - Biophysics Impact factor: 1.000, year: 2011

  20. Psyllium husk gum: an attractive carbohydrate biopolymer for the production of stable canthaxanthin emulsions.

    Science.gov (United States)

    Gharibzahedi, Seyed Mohammad Taghi; Razavi, Seyed Hadi; Mousavi, Seyed Mohammad

    2013-02-15

    The physical stability of the ultrasonically prepared emulsions containing canthaxanthin (CX) produced by Dietzia natronolimnaea HS-1 strain was maximized using a face central composite design (FCCD) of response surface methodology (RSM). The linear and interaction effects of main emulsion components (whey protein isolate (WPI, 0.4-1.2 wt%), psyllium husk gum (PHG, 1.5-4.5 wt%) and coconut oil (CO, 5-10 wt%)) on the stability were studied. The density, turbidity and droplet size of emulsions were also characterized to interpret the stability data. A significant second-order polynomial model was established (p<0.0001). Maximum stability of 98.8% was predicted at the optimum levels of formulation variables (WPI concentration 1.20 wt%, PHG content 3.30 wt%, CO concentration 5.43 wt%). The results also demonstrated that CO and WPI concentration had greater effect on the droplet size and density values, whereas the PHG:WPI ratio had a rather greater effect on the turbidity values. Copyright © 2012 Elsevier Ltd. All rights reserved.

  1. Thermodynamic and kinetic study of volatile compounds in biopolymer based dispersions.

    Science.gov (United States)

    Samavati, Vahid; Emam-Djomeh, Zahra; Mehdinia, Ali

    2014-01-01

    Partitioning and release of ethyl acetate and diacetyl from two matrices with a different composition was studied by applying static head space gas chromatography. Two matrices with a different composition have been developed: one containing carbohydrates (Tragacanth gum) and in the second one, called complex matrix, a lipid (oleic acid) was added. The roles of carbohydrate (Tragacanth gum) and lipid (oleic acid) on the retention of all the aroma compounds were pointed out. Changes in the composition of matrices exhibited a considerable effect on the thermodynamic component as expressed by the air/liquid partition coefficient (Ka/l) values at equilibrium (20 °C). The kinetic study of the release from these matrices had shown a decrease of the initial rate of release (Ri) by reference with water. The rheological properties of all matrices were investigated and the flow behaviour of all matrices was successfully modelled with power law and Ellis models and power law model was found as the better model to describe the flow behaviour of dispersions. Copyright © 2013 Elsevier Ltd. All rights reserved.

  2. Conductivity and electrical properties of corn starch-chitosan blend biopolymer electrolyte incorporated with ammonium iodide

    Science.gov (United States)

    Yusof, Y. M.; Shukur, M. F.; Illias, H. A.; Kadir, M. F. Z.

    2014-03-01

    This work focuses on the characteristics of polymer blend electrolytes based on corn starch and chitosan doped with ammonium iodide (NH4I). The electrolytes were prepared using the solution cast method. A polymer blend comprising 80 wt% starch and 20 wt% chitosan was found to be the most amorphous blend and suitable to serve as the polymer host. Fourier transform infrared spectroscopy analysis proved the interaction between starch, chitosan and NH4I. The highest room temperature conductivity of (3.04 ± 0.32) × 10-4 S cm-1 was obtained when the polymer host was doped with 40 wt% NH4I. This result was further proven by field emission scanning electron microscopy study. All electrolytes were found to obey the Arrhenius rule. Dielectric studies confirm that the electrolytes obeyed non-Debye behavior. The temperature dependence of the power law exponent s for the highest conducting sample follows the quantum mechanical tunneling model.

  3. Biopolymer molecular weight control by radiation treatment for functional property improvement

    Energy Technology Data Exchange (ETDEWEB)

    Lam, Nguyen Duy; Diep, Tran Bang; Quynh, Tran Minh; Hung, Nguyen Manh [Vietnam Atomic Energy Commission, Institute for Nuclear Science and Techniques, Caugiay, Hanoi (Viet Nam); Nagasawa, Naotsugu; Kume, Tamikazu [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment

    2002-03-01

    Solid-state radiation treatment of chitosan an dose range of 30-100 kGy and of gelatin at dose range of 30-40 kGy significantly improved the water-stability of shrimp feed. In these dose ranges, the viscosity-average molecular weight (Mv) of bioadhesive was reduced from 552,000 to 250,000-130,000 and from 57,000 to 38,000-32,000 for chitosan and gelatin, respectively. Gelatin, which has been irradiated in liquid state, could not be used as bioadhesive due to the forming of higher macromolecules based on chaincrosslinks. Liquid-state radiation treatment, in comparison with solid-state irradiation at 100 kGy, required only dose of 4-6 kGy for similar MW and for the same optimal improvement of adhesive property. Radiation treatment with 60-100 kGy maximally enhanced the anti-microbial activity of chitosan. In addition, the optimal dose required for activity is depended on chitosan origin. Chitosan with initial MW of 830,000 required dose of 100 kGy to reduce to 120,000, while other kind of chitosan with initial MW of 550,000 required dose of 60-75 kGy to reduce to 170,000-150,000 for optimal enhancement. The antimicrobial activity is regulated by not only MW but also by its distribution. Irradiated chitosan that has largest width of MW distribution (Mw/Mn) may possesses highest antimicrobial activity. Result from fractionation by using centrifugal filter devices showed that fraction of 3-5 x 10{sup 4} has mainly contributed to the suppression of microbial growth. (author)

  4. Valorization of glycerol through the production of biopolymers: the PHB case using Bacillus megaterium.

    Science.gov (United States)

    Naranjo, Javier M; Posada, John A; Higuita, Juan C; Cardona, Carlos A

    2013-04-01

    In this work technical and economic analyses were performed to evaluate the glycerol transformation into Polyhydroxybutyrate using Bacillus megaterium. The production of PHB was compared using glycerol or glucose as substrates and similar yields were obtained. The total production costs for PHB generation with both substrates were estimated at an industrial scale. Compared to glucose, glycerol showed a 10% and 20% decrease in the PHB production costs using two different separation schemes respectively. Moreover, a 20% profit margin in the PHB sales price using glycerol as substrate resulted in a 166% valorization of crude glycerol. In this work, the feasibility of glycerol as feedstock for the production of PHB at laboratory (up to 60% PHB accumulation) and industrial (2.6US$/kgPHB) scales is demonstrated. Copyright © 2013 Elsevier Ltd. All rights reserved.

  5. Efficient utilization of crude glycerol as fermentation substrate in the synthesis of poly(3-hydroxybutyrate) biopolymers

    Science.gov (United States)

    One refined and 2 crude glycerol samples were utilized to produce poly(3-hydroxybutyrate) (PHB) by Pseudomonas oleovorans NRRL B-14682. Fermentation conditions were determined to efficiently utilize glycerol while maintaining PHB yields. A batch culture protocol including 1% glycerol and an aerati...

  6. Extraction and characterization of gelatin biopolymer from black tilapia (Oreochromis mossambicus) scales

    Energy Technology Data Exchange (ETDEWEB)

    Sockalingam, K., E-mail: gd130106@siswa.uthm.edu.my; Abdullah, H. Z., E-mail: hasan@uthm.edu.my [Faculty of Mechanical and Manufacturing Engineering, Universiti Tun Hussein Onn Malaysia, 86400 Parit Raja, Batu Pahat, Johor (Malaysia)

    2015-07-22

    Black tilapia (Oreochromis mossambicus) fish wastes (scales) were evaluated for its suitability as sources of gelatin. Scales were subjected to acid treatment for demineralization before it undergoes thermal extraction process. The raw scales were characterized via Scanning Electron Microscopy (SEM), which demarcated the cycloid pattern of the scales. SEM images also reveal the presence of collagen fiber in the fish scale. The black tilapia fish scales yields 11.88 % of gelatin, indicating the possibility of this fish species as sources of gelatin. Further characterizations were done on both raw scale and extracted gelatin through Fourier Transform Infrared Spectroscopy (FTIR) and proximate analysis. The scale gelatin shows high protein content (86.9 %) with low moisture (8.2 %) and ash (1.4 %). This further proves the effectiveness of the demineralization and extraction method used. The black tilapia fish scale is found to be a prospective source of gelatin with good chemical and functional properties.

  7. Extraction of high value added gelatin biopolymer from black tilapia (Oreochromis mossambicus) head bones

    Energy Technology Data Exchange (ETDEWEB)

    Sockalingam, K., E-mail: gd130106@siswa.uthm.edu.my; Abdullah, H. Z., E-mail: hasan@uthm.edu.my [Faculty of Mechanical and Manufacturing Engineering, Universiti Tun Hussein Onn Malaysia, 86400 Parit Raja, Batu Pahat, Johor (Malaysia)

    2015-07-22

    Black tilapia (Oreochromis mossambicus) fish head bones were evaluated for its possibilities in extracting gelatin. Head bones were subjected to pre-treatment with 3% of hydrochloric acid (HCl) for demineralization before undergoes thermal extraction process. The raw head bones were characterized via Scanning Electron Microscopy (SEM) in order to investigate the external and internal surface morphology. SEM images also reveal the presence of collagen fiber with 1 µm diameter in the head bone. The black tilapia fish head bones yields 5.75 % of gelatin in wet weight basis, indicating the possibility of this fish species as sources of gelatin. Further characterizations were done on both raw head bones and extracted gelatin through Fourier Transform Infrared Spectroscopy (FTIR) and proximate analysis. The head bones gelatin shows high protein (10.55%) and ash (3.11 %) content with low moisture. This further proves the effectiveness of demineralization and extraction method used. The black tilapia fish head bones are found to be a prospective source of gelatin with good chemical and functional properties.

  8. Extraction and characterization of gelatin biopolymer from black tilapia (Oreochromis mossambicus) scales

    International Nuclear Information System (INIS)

    Sockalingam, K.; Abdullah, H. Z.

    2015-01-01

    Black tilapia (Oreochromis mossambicus) fish wastes (scales) were evaluated for its suitability as sources of gelatin. Scales were subjected to acid treatment for demineralization before it undergoes thermal extraction process. The raw scales were characterized via Scanning Electron Microscopy (SEM), which demarcated the cycloid pattern of the scales. SEM images also reveal the presence of collagen fiber in the fish scale. The black tilapia fish scales yields 11.88 % of gelatin, indicating the possibility of this fish species as sources of gelatin. Further characterizations were done on both raw scale and extracted gelatin through Fourier Transform Infrared Spectroscopy (FTIR) and proximate analysis. The scale gelatin shows high protein content (86.9 %) with low moisture (8.2 %) and ash (1.4 %). This further proves the effectiveness of the demineralization and extraction method used. The black tilapia fish scale is found to be a prospective source of gelatin with good chemical and functional properties

  9. Laser-induced surface modification of biopolymers – micro/nanostructuring and functionalization

    Science.gov (United States)

    Stankova, N. E.; Atanasov, P. A.; Nedyalkov, N. N.; Tatchev, Dr; Kolev, K. N.; Valova, E. I.; Armyanov, St. A.; Grochowska, K.; Śliwiński, G.; Fukata, N.; Hirsch, D.; Rauschenbach, B.

    2018-03-01

    The medical-grade polydimethylsiloxane (PDMS) elastomer is a widely used biomaterial in medicine for preparation of high-tech devices because of its remarkable properties. In this paper, we present experimental results on surface modification of PDMS elastomer by using ultraviolet, visible, and near-infrared ns-laser system and investigation of the chemical composition and the morphological structure inside the treated area in dependence on the processing parameters – wavelength, laser fluence and number of pulses. Remarkable chemical transformations and changes of the morphological structure were observed, resulting in the formation of a highly catalytically active surface, which was successfully functionalized via electroless Ni and Pt deposition by a sensitizing-activation free process. The results obtained are very promising in view of applying the methods of laser-induced micro- and nano-structuring and activation of biopolymers’ surface and further electroless metal plating to the preparation of, e.g., multielectrode arrays (MEAs) devices in neural and muscular surface interfacing implantable systems.

  10. Oxidative Copper-Enzymes are the Key for Unlocking Recalcitrant Biopolymers

    DEFF Research Database (Denmark)

    Johansen, Katja Salomon

    as the electron donating cofactor for the enzyme. The discovery of LPMOs and the understanding that they constitute the “first wave of attack” by microbial organisms on the most recalcitrant natural polysaccharides, highlights the need to reflect on the specific roles of LPMOs in biology. Many good and relevant...

  11. Conductivity and electrical properties of corn starch–chitosan blend biopolymer electrolyte incorporated with ammonium iodide

    International Nuclear Information System (INIS)

    Yusof, Y M; Shukur, M F; Illias, H A; Kadir, M F Z

    2014-01-01

    This work focuses on the characteristics of polymer blend electrolytes based on corn starch and chitosan doped with ammonium iodide (NH 4 I). The electrolytes were prepared using the solution cast method. A polymer blend comprising 80 wt% starch and 20 wt% chitosan was found to be the most amorphous blend and suitable to serve as the polymer host. Fourier transform infrared spectroscopy analysis proved the interaction between starch, chitosan and NH 4 I. The highest room temperature conductivity of (3.04 ± 0.32) × 10 −4  S cm −1 was obtained when the polymer host was doped with 40 wt% NH 4 I. This result was further proven by field emission scanning electron microscopy study. All electrolytes were found to obey the Arrhenius rule. Dielectric studies confirm that the electrolytes obeyed non-Debye behavior. The temperature dependence of the power law exponent s for the highest conducting sample follows the quantum mechanical tunneling model. (paper)

  12. Evaluation of a cell-biopolymer sorbent for uptake of strontium from dilute solutions

    International Nuclear Information System (INIS)

    Watson, J.S.; Scott, C.D.; Faison, B.D.

    1990-01-01

    Immobilization of Micrococcus luteus within beads of bone gelatin results in a material which is able to adsorb significant quantities of strontium from dilute aqueous solutions analogous to some nuclear industry wastewaters. The mechanism appears to be principally an ion-exchange phenomenon. Both the bone gelatin and the microbial cells contribute to strontium removal; the principal contribution from the cells appears to be sorption onto cell wall material. This particular biosorbent may not be an immediate replacement for conventional ion-exchange materials currently used to remove strontium from wastewaters. However, the study does indicate that relatively inexpensive biological materials can be incorporated into particulate forms such as gel beads and used for the removal of dissolved metal ions from aqueous solution

  13. Physical mechanism for biopolymers to aggregate and maintain in non-equilibrium states.

    Science.gov (United States)

    Ma, Wen-Jong; Hu, Chin-Kun

    2017-06-08

    Many human or animal diseases are related to aggregation of proteins. A viable biological organism should maintain in non-equilibrium states. How protein aggregate and why biological organisms can maintain in non-equilibrium states are not well understood. As a first step to understand such complex systems problems, we consider simple model systems containing polymer chains and solvent particles. The strength of the spring to connect two neighboring monomers in a polymer chain is controlled by a parameter s with s → ∞ for rigid-bond. The strengths of bending and torsion angle dependent interactions are controlled by a parameter s A with s A  → -∞ corresponding to no bending and torsion angle dependent interactions. We find that for very small s A , polymer chains tend to aggregate spontaneously and the trend is independent of the strength of spring. For strong springs, the speed distribution of monomers in the parallel (along the direction of the spring to connect two neighboring monomers) and perpendicular directions have different effective temperatures and such systems are in non-equilibrium states.

  14. Enhancing Growth of Vigna radiata in the Presence of Pseudomonas aeruginosa Biopolymer and Metarhizium anisopliae Spores

    Directory of Open Access Journals (Sweden)

    Bhagwan N. Rekadwad

    2016-01-01

    Full Text Available Exopolysaccharide producing Pseudomonas aeruginosa NCIM 2945 (PANCL belonging to gamma-proteobacterium and entomopathogenic fungus Metarhizium anisopliae MCC 1129 (MAMCC belonging to Ascomycota were studied for their morphological features biochemical characteristics and plant growth promotion ability. Optimum growth of PANCL was recorded after 24 h at temperature 30°C and pH 7.0. Gram-negative PANCL appeared as white in color, one mm size, circular, opaque, and nonconsistent elevated colonies with entire margin. It has utilized dextrose, fructose, maltose, and sorbitol as carbon source and produced acid in the medium. PANCL was sensitive to Polymyxin B (300 µgm/disc followed by Neomycin (30 µgm/disc, Gentamycin (10 µgm/disc, and Chloramphenicol (30 µgm/disc. PANCL has secreted extracellular lipase, amylase, protease, and exopolysaccharides (EPS. Another fungal strain MAMCC sporulated after 168 h at temperature 30°C and pH 7.0. MAMCC has septate-white mycelium and bears dirty green colored spores. Growth of MAMCC was enhanced in the presence of Neem and Karela-Amla oil (0.1 mL each. Extracellular polysaccharide produced by PANCL and spores of MAMCC promoted growth of dicotyledon Vigna radiata (Mung individually as well as in consortium. Considerable increase in dry weight of Vigna radiata was recorded. Thus, reported PANCL and MAMCC strains have promoted growth Vigna radiata and may be a solution for sustainable agriculture.

  15. Polysaccharide biopolymers modified with titanium or nickel nanoparticles for removal of radionuclides from aqueous solutions

    Czech Academy of Sciences Publication Activity Database

    Pospěchová, J.; Brynych, V.; Štengl, Václav; Tolasz, Jakub; Langecker, Jens; Bubeníková, M.; Szatmary, L.

    2016-01-01

    Roč. 307, č. 2 (2016), s. 1303-1314 ISSN 0236-5731 Institutional support: RVO:61388980 Keywords : cellulose * chitin * composite nanomaterial Subject RIV: CA - Inorganic Chemistry Impact factor: 1.282, year: 2016

  16. Mussel-inspired polydopamine biopolymer decorated with magnetic nanoparticles for multiple pollutants removal

    International Nuclear Information System (INIS)

    Zhang, Shengxiao; Zhang, Yuanyuan; Bi, Guoming; Liu, Junshen; Wang, Zhigang; Xu, Qiang; Xu, Hui; Li, Xiaoyan

    2014-01-01

    Highlights: • The Fe 3 O 4 /PDA hybrid material was synthesized and characterized. • The PDA polymer was firstly applied in environmental remediation. • The Fe 3 O 4 /PDA exhibited high adsorption capacity for multiple pollutants. • Removal efficiencies of pollutants with Fe 3 O 4 /PDA were pH dependent. - Abstract: The polydopamine polymer decorated with magnetic nanoparticles (Fe 3 O 4 /PDA) was synthesized and applied for removal of multiple pollutants. The resulted Fe 3 O 4 /PDA was characterized with elemental analysis, thermo-gravimetric analyses, vibrating sample magnetometer, high resolution transmission electron microscope, Fourier transform infrared spectra, and X-ray photoelectron spectroscopy. The self-polymerization of dopamine could be completed within 8 h, and Fe 3 O 4 nanoparticles were embedded into PDA polymer. Superparamagnetism and large saturation magnetization facilitated collection of sorbents with a magnet. Based on the catechol and amine groups, the PDA polymer provided multiple interactions to combine with pollutants. To investigate the adsorption ability of Fe 3 O 4 /PDA, heavy metal ions and dyes were selected as target pollutants. The adsorption of pollutants was pH dependent due to the variation of surface charges at different solution pH. The removal efficiencies of cation pollutants enhanced with solution pH increasing, and that of anion pollutant was just the opposite. Under the optimal solution pH, the maximum adsorption capacity calculated from Langmuir adsorption isotherm for methylene blue, tartrazine, Cu 2+ , Ag + , and Hg 2+ were 204.1, 100.0, 112.9, 259.1, and 467.3 mg g −1 , respectively. The Fe 3 O 4 /PDA shows great potential for multiple pollutants removal, and this study is the first application of PDA polymer in environmental remediation

  17. Raster microdiffraction with synchrotron radiation of hydrated biopolymers with nanometre step-resolution: case study of starch granules

    International Nuclear Information System (INIS)

    Riekel, C.; Burghammer, M.; Davies, R. J.; Di Cola, E.; König, C.; Lemke, H.T.; Putaux, J.-L.; Schöder, S.

    2010-01-01

    Radiation damage propagation was examined in starch granules by synchrotron radiation micro- and nano-diffraction techniques from cryo- to room temperatures. Careful dose limitation allowed raster-diffraction experiments with 500 nm step resolution to be performed. X-ray radiation damage propagation is explored for hydrated starch granules in order to reduce the step resolution in raster-microdiffraction experiments to the nanometre range. Radiation damage was induced by synchrotron radiation microbeams of 5, 1 and 0.3 µm size with ∼0.1 nm wavelength in B-type potato, Canna edulis and Phajus grandifolius starch granules. A total loss of crystallinity of granules immersed in water was found at a dose of ∼1.3 photons nm −3 . The temperature dependence of radiation damage suggests that primary radiation damage prevails up to about 120 K while secondary radiation damage becomes effective at higher temperatures. Primary radiation damage remains confined to the beam track at 100 K. Propagation of radiation damage beyond the beam track at room temperature is assumed to be due to reactive species generated principally by water radiolysis induced by photoelectrons. By careful dose selection during data collection, raster scans with 500 nm step-resolution could be performed for granules immersed in water

  18. Microencapsulated cells of Lactobacillus paracasei subsp. paracasei in biopolymer complex coacervates and their function in a yogurt matrix.

    Science.gov (United States)

    Bosnea, L A; Moschakis, T; Biliaderis, C G

    2017-02-22

    L. paracasei subsp. paracasei E6 cells were encapsulated by complex coacervation using whey protein isolate (WPI) and gum arabic and introduced in stirred yogurts after fermentation. For comparison purposes, yogurts without addition of L. paracasei and yogurts with free cells of L. paracasei were produced. The survival of free and microencapsulated L. paracasei cells was evaluated during storage of the yogurts for 45 days at 4 °C. In addition, yogurts were exposed to simulated gastric juice and the reduction in viable numbers of L. paracasei cells was assessed. The effect of complex coacervates' addition on the rheological properties of yogurts was also evaluated. Yogurts containing encapsulated L. paracasei cells showed a slightly improved cell survival (≤0.22 log CFU g -1 reduction) during storage when compared to yogurts containing free cells (≤0.64 log CFU g -1 reduction). Moreover, the microencapsulated L. paracasei cells exhibited greater survival compared to free cells upon exposure of the yogurt samples to simulated gastric juice (pH 2.0) for 3 h. Finally, the incorporation of complex coacervates did not significantly affect the rheological properties of yogurts especially when added at concentrations less than 10% w/w. Consequently, the inclusion of microencapsulated bacteria by complex coacervation in yogurts, could become an effective vehicle for successful delivery of probiotics to the gut, and hence contributing to the improvement of the gastrointestinal tract health, without altering the texture of the product.

  19. Influence of Philosamia ricini silk fibroin components on morphology, secondary structure and thermal properties of chitosan biopolymer film.

    Science.gov (United States)

    Prasong, S; Nuanchai, K; Wilaiwan, S

    2009-09-15

    This study aimed to prepare Eri (Philosamia ricini) Silk Fibroin (SF)/chitosan (CS) blend films by a solvent evaporation method and to compare the blend films with both native SF and CS films. Influence of SF ratios on the morphology, secondary structure and thermal decomposition of the CS blend films were investigated. The native SF and CS films were uniform and homogeneous without phase separation. For the blend films, the uniform can be found less than 60% of SF composition. All of SF/CS blend films showed both SF and CS characteristics. FT-IR results showed that the blend films composed of both random coil and beta-sheet with predominant of beta-sheet form. Interaction of intermolecular between SF and CS have occurred which were measured by thermogravimetric thermograms. Increasing of SF contents was leading to the increase of beta-sheet structures which were enhanced the thermal stability of the CS blend films.

  20. The Potential of Silk and Silk-Like Proteins as Natural Mucoadhesive Biopolymers for Controlled Drug Delivery.

    Science.gov (United States)

    Brooks, Amanda E

    2015-01-01

    Drug delivery across mucus membranes is a particularly effective route of administration due to the large surface area. However, the unique environment present at the mucosa necessitates altered drug formulations designed to (1) deliver sensitive biologic molecules, (2) promote intimate contact between the mucosa and the drug, and (3) prolong the drug's local residence time. Thus, the pharmaceutical industry has an interest in drug delivery systems formulated around the use of mucoadhesive polymers. Mucoadhesive polymers, both synthetic and biological, have a history of use in local drug delivery. Prominently featured in the literature are chitosan, alginate, and cellulose derivatives. More recently, silk and silk-like derivatives have been explored for their potential as mucoadhesive polymers. Both silkworms and spiders produce sticky silk-like glue substances, sericin and aggregate silk respectively, that may prove an effective, natural matrix for drug delivery to the mucosa. This mini review will explore the potential of silk and silk-like derivatives as a biocompatible mucoadhesive polymer matrix for local controlled drug delivery.

  1. Novel hierarchically porous carbon materials obtained from natural biopolymer as host matrixes for lithium-sulfur battery applications.

    Science.gov (United States)

    Zhang, Bin; Xiao, Min; Wang, Shuanjin; Han, Dongmei; Song, Shuqin; Chen, Guohua; Meng, Yuezhong

    2014-08-13

    Novel hierarchically porous carbon materials with very high surface areas, large pore volumes and high electron conductivities were prepared from silk cocoon by carbonization with KOH activation. The prepared novel porous carbon-encapsulated sulfur composites were fabricated by a simple melting process and used as cathodes for lithium sulfur batteries. Because of the large surface area and hierarchically porous structure of the carbon material, soluble polysulfide intermediates can be trapped within the cathode and the volume expansion can be alleviated effectively. Moreover, the electron transport properties of the carbon materials can provide an electron conductive network and promote the utilization rate of sulfur in cathode. The prepared carbon-sulfur composite exhibited a high specific capacity and excellent cycle stability. The results show a high initial discharge capacity of 1443 mAh g(-1) and retain 804 mAh g(-1) after 80 discharge/charge cycles at a rate of 0.5 C. A Coulombic efficiency retained up to 92% after 80 cycles. The prepared hierarchically porous carbon materials were proven to be an effective host matrix for sulfur encapsulation to improve the sulfur utilization rate and restrain the dissolution of polysulfides into lithium-sulfur battery electrolytes.

  2. Universal sequence replication, reversible polymerization and early functional biopolymers: a model for the initiation of prebiotic sequence evolution.

    Directory of Open Access Journals (Sweden)

    Sara Imari Walker

    Full Text Available Many models for the origin of life have focused on understanding how evolution can drive the refinement of a preexisting enzyme, such as the evolution of efficient replicase activity. Here we present a model for what was, arguably, an even earlier stage of chemical evolution, when polymer sequence diversity was generated and sustained before, and during, the onset of functional selection. The model includes regular environmental cycles (e.g. hydration-dehydration cycles that drive polymers between times of replication and functional activity, which coincide with times of different monomer and polymer diffusivity. Template-directed replication of informational polymers, which takes place during the dehydration stage of each cycle, is considered to be sequence-independent. New sequences are generated by spontaneous polymer formation, and all sequences compete for a finite monomer resource that is recycled via reversible polymerization. Kinetic Monte Carlo simulations demonstrate that this proposed prebiotic scenario provides a robust mechanism for the exploration of sequence space. Introduction of a polymer sequence with monomer synthetase activity illustrates that functional sequences can become established in a preexisting pool of otherwise non-functional sequences. Functional selection does not dominate system dynamics and sequence diversity remains high, permitting the emergence and spread of more than one functional sequence. It is also observed that polymers spontaneously form clusters in simulations where polymers diffuse more slowly than monomers, a feature that is reminiscent of a previous proposal that the earliest stages of life could have been defined by the collective evolution of a system-wide cooperation of polymer aggregates. Overall, the results presented demonstrate the merits of considering plausible prebiotic polymer chemistries and environments that would have allowed for the rapid turnover of monomer resources and for regularly varying monomer/polymer diffusivities.

  3. Enhancing the Production of Polyhydroxyalkanoate Biopolymer by Azohydromonas Australica Using a Simple Empty and Fill Bioreactor Cultivation Strategy

    Directory of Open Access Journals (Sweden)

    G. Gahlawat

    2018-01-01

    Full Text Available Polyhydroxyalkanoates (PHAs are biodegradable polymers which are considered as an effective alternative for conventional plastics due to their mechanical properties similar to the latter. However, widespread use of these polymers is still hampered due to their high cost of production. This shortcoming could partly be resolved by obtaining high yields and productivity. In the present study, a drain-and-fill strategy of repeated-batch cultivation was adopted for the enhanced production of polyhydroxybutyrate PHB using Azohydromonas australica. In this strategy, 20 % (v/v of the culture broth was removed from the reactor and supplemented with an equal volume of fresh medium. This strategy demonstrated a 3.3 fold and 1.8 fold increase in PHB concentration and productivity, respectively, as compared to batch cultivation. Repeated cultivation had also the benefit of avoiding non-productive time required for cleaning, refilling and sterilization of bioreactor during batch, thereby increasing the overall volumetric productivity and industrial importance of the process.

  4. Enhancing the Production of Polyhydroxyalkanoate Biopolymer by Azohydromonas Australica Using a Simple Empty and Fill Bioreactor Cultivation Strategy

    OpenAIRE

    G. Gahlawat; A. K. Srivastava

    2018-01-01

    Polyhydroxyalkanoates (PHAs) are biodegradable polymers which are considered as an effective alternative for conventional plastics due to their mechanical properties similar to the latter. However, widespread use of these polymers is still hampered due to their high cost of production. This shortcoming could partly be resolved by obtaining high yields and productivity. In the present study, a drain-and-fill strategy of repeated-batch cultivation was adopted for the enhanced production of p...

  5. Nitrous Oxide Abatement Coupled with Biopolymer Production As a Model GHG Biorefinery for Cost-Effective Climate Change Mitigation.

    Science.gov (United States)

    Frutos, Osvaldo D; Cortes, Irene; Cantera, Sara; Arnaiz, Esther; Lebrero, Raquel; Muñoz, Raúl

    2017-06-06

    N 2 O represents ∼6% of the global greenhouse gas emission inventory and the most important O 3 -depleting substance emitted in this 21st century. Despite its environmental relevance, little attention has been given to cost-effective and environmentally friendly N 2 O abatement methods. Here we examined, the potential of a bubble column (BCR) and an internal loop airlift (ALR) bioreactors of 2.3 L for the abatement of N 2 O from a nitric acid plant emission. The process was based on the biological reduction of N 2 O by Paracoccus denitrificans using methanol as a carbon/electron source. Two nitrogen limiting strategies were also tested for the coproduction of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) coupled with N 2 O reduction. High N 2 O removal efficiencies (REs) (≈87%) together with a low PHBV cell accumulation were observed in both bioreactors in excess of nitrogen. However, PHBV contents of 38-64% were recorded under N limiting conditions along with N 2 O-REs of ≈57% and ≈84% in the ALR and BCR, respectively. Fluorescence in situ hybridization analyses showed that P. denitrificans was dominant (>50%) after 6 months of experimentation. The successful abatement of N 2 O concomitant with PHBV accumulation confirmed the potential of integrating biorefinery concepts into biological gas treatment for a cost-effective GHG mitigation.

  6. SYNTHESIS AND CHARACTERIZATION OF CELLULOSE BASED BIO-POLYMER AEROGEL ISOLATED FROM WASTE OF BLUEBERRY TREE (VACCINIUM MYRTILLUS

    Directory of Open Access Journals (Sweden)

    Mehmet KAYA

    2016-09-01

    Full Text Available Cellulose aerogel (CA has highly porous structure, environmentally friendly, thermally stable and flame retardant properties. These properties in material worlds have attracted large interest as a potentially industrial material. In this paper, cellulose aerogel with flame retardant was produced from pruned branches and bushes of blueberries wastes (PBBW. Firstly, cellulose raw material these wastes was obtained and then, cellulose aerogel via freeze-drying, followed by cellulose hydrogel production. Our reports showed that three dimensionally network aerogel structure prepared from NaOH/Urea as scaffold solution. The present cellulose aerogel has excellent flame retardancy, which can extinguish within 140 s. By the way, it was inferred thermal stability performance of cellulose aerogel could be efficient potential thermal insulating material. Besides, this process are sustainable, easily available at low cost and suitable for industrial applications.

  7. Analysis and optimization of flocculation activity and turbidity reduction in kaolin suspension using pectin as a biopolymer flocculant.

    Science.gov (United States)

    Ho, Y C; Norli, I; Alkarkhi, Abbas F M; Morad, N

    2009-01-01

    The performance of pectin in turbidity reduction and the optimum condition were determined using Response Surface Methodology (RSM). The effect of pH, cation's concentration, and pectin's dosage on flocculating activity and turbidity reduction was investigated at three levels and optimized by using Box-Behnken Design (BBD). Coagulation and flocculation process were assessed with a standard jar test procedure with rapid and slow mixing of a kaolin suspension (aluminium silicate), at 150 rpm and 30 rpm, respectively, in which a cation e.g. Al(3+), acts as coagulant, and pectin acts as the flocculant. In this research, all factors exhibited significant effect on flocculating activity and turbidity reduction. The experimental data and model predictions well agreed. From the 3D response surface graph, maximum flocculating activity and turbidity reduction are in the region of pH greater than 3, cation concentration greater than 0.5 mM, and pectin dosage greater than 20 mg/L, using synthetic turbid wastewater within the range. The flocculating activity for pectin and turbidity reduction in wastewater is at 99%.

  8. Thermodynamic and Kinetic Aspects Involved in the Development of Nanocarriers and Drug Delivery Systems Based on Cationic Biopolymers.

    Science.gov (United States)

    Bianco, Ismael D; Alasino, Roxana V; Leonhard, Victoria; Beltramo, Dante M

    2016-01-01

    During the last years we have seen an increasing number of reports describing new properties and potential applications of cationic polymers and derived nanostructures. This review gives a summary of their applications in drug delivery, the preparation methods for nano and microstructures and will attempt to give a glimpse on how their structure, chemical composition and properties may be affected or modulated as to make them suitable for an intended application as drug delivery nanocarriers. The compositional complexity with the existence of several reacting groups makes cationic nanostructures critically sensitive to the contribution of thermodynamic and kinetic parameters in the determination of the type and stability of a particular structure and its ability to respond to changes in environmental conditions in the right time frame. Curiously, and contrarily to what could be expected, despite the fact that cationic polymers can form strong electrostatic interactions the contribution of the entropic component has been often found to be very important for their association with negatively charged supramolecular structures. Some general considerations indicate that when considering a complex multimolecular system like a nanocarrier containing an active ingredient it is frequently possible to find conditions under which enthalpic and entropic contributions are compensated leading to stable structures with a marginal thermodynamic stability (free energy change close to zero) which make them able to respond relatively fast to changes in the environmental conditions and therefore suitable for the design of smart drug delivery systems. Like with other nanocarriers, it should always be kept in mind that the properties of cationic nanocarriers will depend not only on their chemical composition but also on the properties of the structures formed by them.

  9. Use of a biopolymer polyalkylimide filler for facial lipodystrophy in HIV-positive patients undergoing treatment with antiretroviral drugs.

    Science.gov (United States)

    Treacy, Patrick J; Goldberg, David J

    2006-06-01

    To evaluate the efficacy, overall esthetic effect, and safety of a new permanent, polyalkylimide dermal filler in HIV-infected patients with severe facial lipodystrophy. Eleven subjects with severe facial lipodystrophy secondary to HIV infection were injected bilaterally with 15 and 30 cm3 of a polyalkylimide gel into the buccal, malar, and temporal areas of the face in an attempt to restore their facial contour. The youngest treated subject was 31 years of age and the oldest 73 years of age. All 11 subjects received an immediately acceptable therapeutic esthetic effect. Injections were generally well tolerated, with only three adverse events (swelling and bruising) recorded. Subjects, assessed at 3 and 18 months after treatment, continued to show improvement. The immediate benefits of a polyalkylimide gel in the correction and restoration of facial contour in subjects having severe HIV-related facial lipodystrophy were demonstrated. This improvement was still noted at 18 months. The efficacy, ease of injection, and safety profile of polyalkylimide gel make this filling material a potentially attractive treatment for lipodystrophy. These data must be tempered with the need for significant further safety studies to determine whether this long-term filler has a safety profile consistent with other currently popular fillers.

  10. Enhancing organic matter removal, biopolymer recovery and electricity generation from distillery wastewater by combining fungal fermentation and microbial fuel cell.

    Science.gov (United States)

    Ghosh Ray, S; Ghangrekar, M M

    2015-01-01

    For enhancing organic matter removal from cereal-based distillery stillage two-stage treatment consisting of fermentation by Aspergillus awamori followed by microbial fuel cell (MFC) is proposed. Considerable reduction in total and soluble chemical oxygen demand (COD) up to 70% and 40%, respectively, along with 98% reduction of suspended solids (SS) has been achieved during fungal pretreatment. The process generated chitosan, a useful fermentation byproduct from fungal mycelia, as 0.6-0.7g/l of settled sludge with mycelium (3.8% solids). Prior treatment of wastewater with fungal strain enhanced the power generation in MFC by 2.9 times at an organic loading rate of 1.5kgCOD/m(3)day, demonstrating soluble COD reduction of 92% in MFC. While treating distillery wastewater, this two-stage integrated biological process demonstrated overall 99% COD removal and almost complete removal of SS, delivering ample scope for scale-up and industrial application to offer effective solution for distillery wastewater treatment. Copyright © 2014 Elsevier Ltd. All rights reserved.

  11. Effect of ionizing electron beam radiation on properties of edible biopolymers based on isolated soybean protein and cassava starch

    International Nuclear Information System (INIS)

    Uehara, Vanessa Bernardo

    2017-01-01

    In recent decades, there has been a substantial increase in the amount of research focusing on the development and characterization of biodegradable materials, particularly edible films. The use of polymers from renewable sources, prepared from plant products, has gained importance in this approach. Soy protein concentrate and cassava starch may be considered an alternative to petrochemical polymers. Processing by ionizing radiation can be used for the modification of polymers and macromolecules, resulting in new materials with great prospects of industrial use. The food industry, one of the traditionally most innovative industries, requires the constant development of new products. The widely known ability of film forming proteins and polysaccharides is a starting point for the development of new materials that meet the varying requirements of this pungent industry. In this work, films based on manioc starch and isolated soy protein were prepared in two different proportions and later irradiated and analyzed for their mechanical properties, color, water absorption, water vapor permeability, TGA and DSC thermal analysis between others. The films became apparently more soluble and less resistant to drilling with the increased radiation dose applied. Regarding the thermal properties, it was observed that the films with greater protein orientation are more resistant. Properties such as water vapor permeability and water absorption, the films were less permeable at the 40 kGy dose. With regard to water absorption, it was reduced as a function of the radiation dose. Films with good resistance to water vapor and with low absorption are considered efficient for food packaging. Radiation has proven to be a convenient tool in the modification of polymeric materials mainly for the production of soluble films where it is a new trend for bioactive packaging. (author)

  12. Study on the creation of biopolymer materials under micro-gravity; Bisho juryokuka deno seitai kobunshi zairyo no sosei kenkyu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-03-01

    In order to create new functional organic thin film materials, basic data were examined under micro-gravity. Polymerization of pyrrole was affected by micro-gravity after a few minutes from the beginning of reaction. Although relatively uniform particles were obtained, the particle size was finely dependent on conditions. Electrolytic polymerization of conductive organic thin films was yet unstable in reproducibility. On orientation control and thin film formation of protein under gravity-free environment, electrodeposited films were obtained using bacteriorhodopsin film suspension by applying voltage of 6.4V for 9s after 1s from falling. The reproducibility of the number and area of molecular layers was poor. On the study on the formation process of organic thin films, creation of homogeneous films is probably possible by filtration from suspension under reduced pressure under micro-gravity for a short time. Trial linear polymer tied in a row was obtained by capillary injection of dense polymer solution. The viscous fingering phenomenon of viscoelastic bodies under micro-gravity was compared with that on the ground. 11 refs., 36 figs., 1 tab.

  13. Developing a Material Response Model of Biopolymer-Stabilized Regolith to Predict Micrometeorite Damage of ISRU Habitat Systems

    Data.gov (United States)

    National Aeronautics and Space Administration — The proposed space technology research aims to investigate the micrometeorite impact performance of Regolith Biocomposite (RBC), an innovative in-situ material...

  14. Biopolymer/gold nanoparticles composite plasmonic thermal history indicator to monitor quality and safety of perishable bioproducts.

    Science.gov (United States)

    Wang, Yi-Cheng; Lu, Lin; Gunasekaran, Sundaram

    2017-06-15

    Quality and safety of perishable products such as foods, pharmaceutics, and biologicals is a constant concern. We have developed a plasmonic thermal history indicator (THI) taking advantage of the localized surface plasmon resonance of gold nanoparticles (AuNPs) synthesized in situ in alginate, a natural polysaccharide. The color of the THIs becomes more intense with increased storage temperature and/or duration, with the color changing from grey to red with time of exposure at high temperature (40°C). The results suggest that decreasing viscosity with increasing number of AuNPs being synthesized in the system, along with aggregation of newly synthesized AuNPs onto larger ones and their settling are potentially responsible for the distinct color change observed. The use of alginate in the THIs also facilitates fabricating them as solid hydrogel matrices by adding divalent calcium ions. This alginate-AuNPs THI system is tunable by altering its composition to suit different time-temperature monitoring scenarios and the color-change reaction is irreversible. The THI provides a convenient, reliable, safe, and inexpensive means for tracking the thermal history of perishable products without the need for a read-out device. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Chemical composition of pseudo-phlobaphinite precursors: implications for the presence of aliphatic biopolymers in vitrinite from coal

    Energy Technology Data Exchange (ETDEWEB)

    Etuan Zhang; Hatcher, P.G.; Davis, A. (Pennsylvania State University, University Park, PA (United States). Dept. of Materials Science and Engineering)

    1993-08-01

    Pseudo-phlobaphinite cell inclusions in a buried stem of angiospermous wood of [ital Rhizophora mangle] from Mangrove Lake, Bermuda have been investigated petrographically and chemically. Optical and scanning electron microscopy reveal that the light wood from inner sections of the stem consists predominantly of cell walls with few cell inclusions, whereas the dark wood from outer portion of the stem is composed of both cell walls and cell inclusions which are believed to represent pseudophlobaphinite precursors. [sup 13]C NMR spectroscopy reveals the presence of lignin and tannin structures within the cell walls. The wood also displays resonances suggestive of aliphatic components. The NMR results are further supplemented and confirmed by flash pyrolysis gas chromatography and mass spectrometry analyses. The pyrogram of the cell-wall dominated light wood is characterized by peaks related to both syringyl and guaiacyl units. The major pyrolysis products from the dark wood, however, are a homologous series of long-chain n-alkanes, n-alk-l-enes and [alpha],[omega]-alkadienes extending from chain length C[sub 10] to C[sub 30]. These aliphatic components arise from the material associated with the pseudophlobaphinite cell inclusions. Py-gc/ms analysis of a humic acid extracted from the sediments surrounding the studied wood consists almost exclusively of a homologous series of straight-chain alkanes, alkenes and alkadienes up to C[sub 30]. The striking resemblance between programs of the pseudo-phlobaphinite precursor and humic acid suggests that the possible mechanism for the formation of the pseudo-phlobaphinite is migration and deposition of humic acid into cell lumina. 72 refs., 5 figs., 1 tab.

  16. Biopolymer nanogels improve antibacterial activity and safety profile of a novel lysine-based α-peptide/β-peptoid peptidomimetic

    DEFF Research Database (Denmark)

    Kłodzińska, Sylvia Natalie; Molchanova, Natalia; Franzyk, Henrik

    2018-01-01

    Infections caused by Pseudomonas aeruginosa are associated with high morbidity and mortality, especially in immunocompromised patients. These bacteria frequently grow within a biofilm matrix, rendering therapy with conventional antibiotics inefficient; a fact that emphasizes the need for new...

  17. Study of interactions between octyl-β-D-glucopyranoside and the hydroxyethyl-cellulose biopolymer in aqueous solution

    International Nuclear Information System (INIS)

    Villegas-Pañeda, Ximena; Pérez-Casas, Silvia; Hernández-Baltazar, Efrén; Chávez-Castellanos, Angel E.

    2014-01-01

    Graphical abstract: - Highlights: • Interactions in mixed micelles to be used as drug carriers were studied. • We tested this system to nanoencapsulate the metronidazole as a drug model. • Characteristic concentrations for the micelle formation process were obtained. • The micelles formation in all cases is spontaneous, and entropy driven. • Thermodynamic properties of demicellization for the mixed micelles were determined. - Abstract: (Surfactant + polymer) systems play an important role in drug delivery. They control the drug release rate by improving solubility, minimizing degradation, contributing to the reduction of toxicity and facilitating drug administration. Physicochemical properties of surfactant/polymer systems used in controlled drug release are affected by the composition of the mixture. The study of the physicochemical behavior of these mixtures allows the design of more suitable drug pharmaceutical formulation according to its chemical structure. In this paper, critical micelle concentration (CMC), saturation concentration (C 2 ), critical aggregation concentration (CAC) and thermodynamic parameters, such as enthalpy (ΔH), Gibbs free energy (ΔG) and the temperature multiplied by entropy (TΔS) for the demicellization process were determined by isothermal titration calorimetry (ITC), for octyl-β-D-glucopyranoside (OGP) and hydroxyethyl-cellulose (HEC) aqueous solutions in order to construct a phase diagram suitable for the study of the interactions in each region and to choose the appropriate system for drug delivery. The interpretation of the results is supported by the analysis of particle size measurements by dynamic light scattering (DLS)

  18. Production of extracellular enzymes and degradation of biopolymers by saprotrophic microfungi from the upper layers of forest soil

    Czech Academy of Sciences Publication Activity Database

    Baldrian, Petr; Voříšková, Jana; Dobiášová, Petra; Merhautová, Věra; Lisá, Ludmila; Valášková, Vendula

    2011-01-01

    Roč. 338, 1-2 (2011), s. 111-125 ISSN 0032-079X R&D Projects: GA MŠk LC06066; GA MŠk OC 155; GA MŠk OC08050 Institutional research plan: CEZ:AV0Z50200510 Keywords : Lignocellulose * Soil microfungi * Chitin Subject RIV: EE - Microbiology, Virology Impact factor: 2.733, year: 2011

  19. Biopolymer as an Alternative to Petroleum-based Polymers to Control Soil Erosion: Iowa Army Ammunition Plant

    Science.gov (United States)

    2013-11-01

    be aware of wind directions and attempt to coordinate field activities and gasoline powered equipment so that exhaust fumes and chemical vapors are...exposed skin and respiratory tract. Section 4: First Aid Measures Eye Contact: Skin Contact: Inhalation : Wash with water and seek medical...Skin: Use safety gloves as with any chemicals. Inhalation : None normally required. If dust possible, a NIOSH approved respirator should be worn. C

  20. Biopolymers as an Alternative to Petroleum-Based Polymers for Soil Modification; ESTCP ER-0920: Treatability Studies

    Science.gov (United States)

    2012-08-01

    constructed at the angle of repose characteristic of earthen berms in slope stability boxes. Prior to construction, experimental soils were amended with...Nanotechnology: Future military environmental health considerations. Technology Forecasting and Social Change 73: 128-137. Goto, N., O. Mitamura, and H