Characteristics Of Biopolymers Research Articles

Importance of origin and characteristics of biopolymers in reversible and irreversible fouling of ultrafiltration membranes

The present work compares the chemical properties of isolated biopolymers of different origins and their fouling potential during ultrafiltration (UF). The biopolymers were extracted from secondary wastewater effluent as effluent organic matter (EfOM) and from surface water as natural organic matter (NOM). Multiple analytical techniques were used to characterize the isolates. The characterization results revealed that EfOM biopolymers were more enriched in protein-type structures compared to the NOM organics, and they presented significant differences in the reversibility of membrane fouling. Dissolved in pure water, EfOM biopolymers led to more irreversible fouling than that caused by NOM isolates. Dosing divalent cations (e.g., Ca2+) into the solutions increased the irreversibility of both types of fouling, while aggravating NOM fouling more significantly. Further investigation was conducted to understand the interaction between EfOM and NOM biopolymers during formation of the fouling layer. The results showed that the interaction between these two types of organics was negligible in the absence of salts. These findings highlight the importance of a comprehensive understanding of biopolymers from different origins, considering their chemical properties and water chemistry, which have valuable implications for selecting suitable membrane fouling control strategies for treating water from different origins.

State-of-the-art review on efficacy of xanthan gum and guar gum inclusion on the engineering behavior of soils

Soil amelioration is a challenging task in bulk civil engineering applications such as embankment slopes, landfill liner, pavement subgrade, retaining wall back fill. The conventional chemical stabilization techniques (i.e., cement, calcium hydroxide, sodium chloride, calcium chloride, etc.) inherently suffer from associated carbon emissions during their production stages. With the advent of biopolymers derived from natural sources having low embodied energy levels, they can replace conventional stabilizers. The current review article highlights the significant properties of two such biopolymers, i.e., xanthan gum (XG) and guar gum (GG), and their innate potential in stabilizing different soil types including mine tailings. The issues arising with wet and dry mixing of these biopolymers and suggested measures have been critically addressed. The degradation characteristics of biopolymers, which limit their use for bulk civil engineering applications, have been critically discussed, and the potential solutions to overcome durability issues are suggested. Future applications of these biopolymers in geoenvironmental engineering relying on the metal encapsulation properties are discussed in detail. It is believed that the selected biopolymers in this review are renewable, sustainable and remarkable materials with low embodied energy levels and low carbon footprint values compared to existing conventional stabilizers.

A review on grafted, crosslinked and composites of biopolymer Xanthan gum for phasing out synthetic dyes and toxic metal ions from aqueous solutions

Biopolymer Xanthan gum (XG), an exo-polysaccharide obtained from the fermentation of simple sugars by bacteria Xanthomonas campestris under aerobic conditions exhibits interesting properties like biodegradability, high viscosity at a low shear rate and stability under a wide range of temperature and pH. These characteristics properties render it accessible to utilize as a stabilizer, suspending as well as an emulsifying agent in food industries, petroleum and oil refining industries, cosmetic industries, and as an adsorbent in wastewater treatment. However, XG hydrophilicity and water solubility characteristics not only restrict its application domain but also affect its thermal stability during processing. Therefore, the efforts are directed to improve its application spectrum by modifying the physical and chemical characteristics of biopolymer, taking advantage of the presence of different amenable functional moieties in XG. The chemical modifications of XG include the formation of cross-linked polymers, grafting of monomer to base polymers manipulating the functionality by removal/addition of chemical groups. Currently, the emphasis is on the development of XG based grafted/crosslinked bionanocomposites which can be tailored as a noble adsorbent for wastewater treatment for the remotion of toxic metals, coloured synthetic dyes and other industrial effluents from the aqueous medium. The emphasis of present review article is to address the structural, physical characteristics along with the focus on the development of chemically modified XG viz. grafted, crosslinked, nanocomposites, and functionally modified biopolymer. The potential applications of these modified XG polymers for phasing out synthetic dyes and transition metals ions from aqueous systems have been deliberated.

Application of Polysaccharide Biopolymer in Petroleum Recovery.

Polysaccharide biopolymers are biomacromolecules derived from renewable resources with versatile functions including thickening, crosslinking, adsorption, etc. Possessing high efficiency and low cost, they have brought wide applications in all phases of petroleum recovery, from well drilling to wastewater treatment. The biopolymers are generally utilized as additives of fluids or plugging agents, to correct the fluid properties that affect the performance and cost of petroleum recovery. This review focuses on both the characteristics of biopolymers and their utilization in the petroleum recovery process. Research on the synthesis and characterization of polymers, as well as controlling their structures through modification, aims to develop novel recipes of biopolymer treatment with new application realms. The influences of biopolymer in many petroleum recovery cases were also evaluated to permit establishing the correlations between their physicochemical properties and performances. As their performance is heavily affected by the local environment, screening and testing polymers under controlled conditions is the necessary step to guarantee the efficiency and safety of biopolymer treatments.

Prediction of Bio-Polymer Characteristics by Applying Rentato Panelli Mathematical Model

Recently, the intense interest for bio-polymer for biomedical applications has gone up. This interest was due to patients researchers, and the medical world seeking for effective solutions to their serious challenges, such as the need to repair or, replace, substitute organs or tissues. In current article, Rentato Panelli mathematical equation utilize to understand and track parameters refer to a physical significant, deformation nature and shape memory degree and of two types of bio-polymer derivative mixtures, Avicel 102 and Sodium Starch Glycolate (SSG). Panelli constants were stated by using combination of two, known, bio polymer in term of deformation and shape memory specifications to validate of the equation parameters to predict this characteristics for unknown materials which may be part of human body or cardiovascular artificial parts. Constants and coefficients for equation measured by applying low pressure ranging from 15 to 75 Mpa. The issues emerging from the findings relate specifically to depth in-die analysis. The most interesting findings was the Panelli equation parameters are perfectly valid in representing bio-polymer characteristics under stress. These parameters and characteristics are able to assess the features of the bio-polymer which sometimes become beyond the scope unless defined by using specific instrumentation. In addition, these parameters can decide the applied pressure that achieve particular density in the manufacturing conditions. These parameters determine process conditions that produce desired biomedical engineering application as bio ink for 3D printing, artificial organs, and drug delivery system which is difficult or rather impossible without use classical methods.

Use of Biomaterials for 3D Printing by Fused Deposition Modeling Technique: A Review.

Three-dimensional (3D) printing is a revolutionary manufacturing technique that can fabricate a 3D object by depositing materials layer by layer. Different materials such as metals, polymers, and concretes are generally used for 3D printing. In order to make 3D printing sustainable, researchers are working on the use of different bioderived materials for 3D printing. Because of the abundant and sustainable sources, and versatile properties, biomaterials are considered as the potential candidates that have the ability to replace petroleum-based polymers. This review highlights the basic overview of fused deposition modeling (FDM) technique of 3D printing and recent developments that have occurred on FDM printing using biomaterials. Specifically, FDM printing process, final properties, and characteristics of biopolymers, their composites, and polymers containing biofillers are discussed.

Characterization of Hidden Chirality: Two-Fold Helicity in β-Strands

A β-strand is a component of a β-sheet and is an important structural motif in biomolecules. An α-helix has clear helicity, while chirality of a β-strand had been discussed on the basis of molecular twists generated by forming hydrogen bonds in parallel or non-parallel β-sheets. Herein we describe handedness determination of two-fold helicity in a zig-zag β-strand structure. Left- (M) and right-handedness (P) of the two-fold helicity was defined by application of two concepts: tilt-chirality and multi-point approximation. We call the two-fold helicity in a β-strand, whose handedness has been unrecognized and unclarified, as hidden chirality. Such hidden chirality enables us to clarify precise chiral characteristics of biopolymers. It is also noteworthy that characterization of chirality of high dimensional structures like a β-strand and α-helix, referred to as high dimensional chirality (HDC) in the present study, will contribute to elucidation of the possible origins of chirality and homochirality in nature because such HDC originates from not only asymmetric centers but also conformations in a polypeptide chain.

Biopolymers: Applications in wound healing and skin tissue engineering.

Wound is a growing healthcare challenge affecting several million worldwide. Lifestyle disorders such as diabetes increases the risk of wound complications. Effective management of wound is often difficult due to the complexity in the healing process. Addition to the conventional wound care practices, the bioactive polymers are gaining increased importance in wound care. Biopolymers are naturally occurring biomolecules synthesized by microbes, plants and animals with highest degree of biocompatibility. The bioactive properties such as antimicrobial, immune-modulatory, cell proliferative and angiogenic of the polymers create a microenvironment favorable for the healing process. The versatile properties of the biopolymers such as cellulose, alginate, hyaluronic acid, collagen, chitosan etc have been exploited in the current wound care market. With the technological advances in material science, regenerative medicine, nanotechnology, and bioengineering; the functional and structural characteristics of biopolymers can be improved to suit the current wound care demands such as tissue repair, restoration of lost tissue integrity and scarless healing. In this review we highlight on the sources, mechanism of action and bioengineering approaches adapted for commercial exploitation.

Growth phenomena in biopolymer complexes composed of heated WPI and pectin

An unusual growth behaviour of biopolymer complexes composed of whey protein isolate (WPI) and pectin with various degrees of esterification (DE) was investigated. The formation and stability of complexes was studied at the isoelectric point (pI) of the protein since most likely hydrophobic rather than electrostatic interaction forces dominate the complexation process. As such, biopolymer particles were generated under slightly acidic conditions (pH 4.6) which had been subjected to various heat treatments (ϑ = 25–80 °C). Dynamic light scattering and ζ-potential measurements were utilized to examine the formation and stability of pectin-protein complexes. The results revealed that the initial size and surface charge of biopolymer particles depended on the pectins DE. Use of low-methoxylated pectins (DE 10%) led to the formation of small-sized complexes with narrow particle size distributions and a higher magnitude of surface charge. All biopolymer samples showed a time-dependent increase in size. A linear regression analysis revealed that the particle volume (r3) increased linearly with time. It was demonstrated that the growth rates increased with decreasing temperatures, increasing DE, and decreasing pectin concentrations, respectively. However, the ζ-potential remained unchanged over the entire storage time tested. These results suggest that the control over processing conditions, biopolymer characteristics, and physicochemical interactions might lead to the fabrication of particles with specific particle sizes and surface charges.

A comparative study of adhesion by bacterial isolates of marine origin

Extracellular polymeric substances (EPS) are one of the main components of microbial biofilms, which are markedly influenced by the chemical composition and functional properties of these EPS. This study quantified the adherence capacity of 29 bacterial strains isolated from marine water in Luria–Bertani and Bushnel-Haas culture media. Their capacity to produce EPS and the influence of the culture conditions on the chemical composition and emulsifying activity of their synthesised exopolymers was determined. Eighteen of the bacterial strains in this study produced EPS while eleven were unable to do so. Surface adherence was associated with bacterial growth and with the capacity of the isolates to synthesise EPS. Pseudoalteromonas elyakovii W18 showed the highest values for surface adherence and synthesised a non-bioemulsifier EPS. Principal component analysis (PCA) was used to establish the relationships between the biopolymer characteristics and surface adherence. The efficient adherence of P elyakovii on the surface of K1 (Anoxkaldnes©) carrier was confirming by scanning electronic microscopy.

Polysaccharide Characterisation of Marine Organic Matter in a Coastal Station of the Gulf of Trieste (Northern Adriatic Sea, Italy)

In the last two decades the presence and distribution of large aggregates in the Mediterranean Sea have encouraged to study the macromolecular features of dissolved organic matter and the implication of molecular characteristics of biopolymers on the aggregation processes. Monthly monitoring of marine carbohydrates in a coastal station of the Northern Adriatic sea during years 2001–2003 at 0.5, 10 and 15 m depth showed different pattern for dissolved and total carbohydrates in concurrence of the massive formation of aggregates. Since March to June 2004 marine water was collected for the partition experiment. The polysaccharide component was isolated by ultrafiltration. The monosaccharide compositions were very similar to those obtained from Adriatic pelagic mucilage. In June a significant reduction of the concentration of the low molecular weight polysaccharidic fraction was observed, in conjunction with the rapid increase of the high-molecular weight polysaccharides (HMW). In addition, the concentrations of deoxysugar (rhamnose and fucose) in the particulate matter decreased, and the fucose disappeared in June. These two monosaccharides and galactose may be considered bioindicators of the different degradation steps of marine polysaccharidic matter. This enrichment suggested that galactose-rich polysaccharides are able to undergo aggregate formation. Scanning electron microscopy and AFM imaging on extracted fractions showed the presence of fibrillar structures forming a highly branched tri-dimensional network similar to those found in Adriatic pelagic aggregates.

Studies on self‐assembly interactions of proteins and octenyl succinic anhydrate (OSA)‐modified depolymerized waxy rice starch using rheological principles

ABSTRACTDynamic tests (23 °C, pH ∼ 7.0) yielding relaxation times, λ, as a function of frequency and polymer concentration were performed to assess self‐assembly characteristics of biopolymers in aqueous solution. Reduction of λ‐values (slope) up to a critical frequency value (CFV) helps characterize structure formation. Proteins and octenyl succinic anhydrate (OSA)‐modified depolymerized waxy rice starch (DWxRc) show a well‐defined λ‐slope at all concentrations. Except for whey protein isolate (WPI, 0.184 g/L) and 7% OSA‐modified DWxRc (1.84 g/L), the λ‐values of the solutions are comparable (P > 0.05), indicating similar structures. Self‐assembly interaction of α‐lactalbumin (3.68 g/L) with OSA‐modified polysaccharides is observed with 18.4 g/L of 7% OSA‐modified DWxRc (CFV of 0.08 Hz), while WPI (3.68 g/L) exhibits self‐assembly with all polysaccharides and concentrations. Transmission electron microscopy (TEM) of electrostatically precipitated proteins alone or in combination with OSA‐modified polysaccharides confirms that λ−slope and CFV values relate to shape, size, and shear stability of the assembled structures. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43603.

Mechanically modified xanthan gum: Rheology and polydispersity aspects

Xanthan gum solutions were treated with high-pressure homogenization (HPH) in order to provide alternative treatments to enzymatic and chemical modification of this carbohydrate. Rheological properties of the treated and control samples were investigated in detail to gain an understanding of functional consequences of physical modification. The molecular structural properties were investigated via Size exclusion chromatography (SEC) coupled with Multi-angle laser light scattering (MALLS) and Circular dichroism (CD). Structured network of xanthan gum solutions was lost gradually depending on the severity of the HPH treatment as evidenced by the observed changes in the viscosity and viscoelasticity of the treated solutions. Reduction in molecular weight and a significant increase in polydispersity of the polymer were the expected causes of these rheological changes. Observed increase in hydrodynamic volume upon HPH treatment was not surprising and attributed to the loss of structured networks. Changes in the rheological and structural characteristics of biopolymer were irreversible and significant recovery was not detected over a period of 11 weeks.

Physico-chemical and rheological characterization of poly-gamma-glutamic acid produced by a new strain of Bacillus subtilis

The aim of this research was to characterize the γ-PGA produced by Bacillus subtilis BL53, comparing the influence of cultivation time on the rheological and thermal biopolymer characteristics in order to identify its potential applications. Bacterial cultivations were carried out in bioreactors under previously optimized conditions (medium E, 37°C, 2vvm, and 1000rpm) and the produced γ-PGA was extracted from culture broth at 48 and 96h of cultivation. The biopolymer was characterized by measurements of the weight-average molecular mass (Mw) using static light scattering, melting (Tm) and deterioration (Td) temperatures, and rheological properties of the biopolymer solutions. There was no significant difference in Mw for biopolymers obtained in different cultivation times ((1.47±0.30)×106gmol−1 at 48h; (1.49±0.23)×106gmol−1 at 96h). Solutions of biopolymers obtained at 48 and 96h presented Newtonian behavior, whereas the viscosity was higher for the 96h samples, indicating a better interaction solvent–biopolymer. The thermal analysis showed Tm of 134°C and 128°C, whereas Td varied from 130 to 190°C and 130 to 215°C for 48 and 96h samples, respectively. Tm peak area and fusion enthalpy were higher for 96h biopolymer, indicating a higher crystallinity compared to 48h γ-PGA. These characteristics of B.subtilis BL53 γ-PGA support the possibility of its use as thickener and functional ingredient in food, antitumor agent, and biological adhesive in medicine.

Network and Nakamura tridiagonal computational simulation of electrically-conducting biopolymer micro-morphic transport phenomena

Magnetic fields have been shown to achieve excellent fabrication control and manipulation of conductive bio-polymer characteristics. To simulate magnetohydrodynamic effects on non-Newtonian electro-conductive bio-polymers (ECBPs) we present herein a theoretical and numerical simulation of free convection magneto-micropolar biopolymer flow over a horizontal circular cylinder (an “enrobing” problem). Eringen's robust micropolar model (a special case of the more general micro-morphic or “microfluid” model) is implemented. The transformed partial differential conservation equations are solved numerically with a powerful and new code based on NSM (Network Simulation Method) i.e. PSPICE. An extensive range of Hartmann numbers, Grashof numbers, micropolar parameters and Prandtl numbers are considered. Excellent validation is also achieved with earlier non-magnetic studies. Furthermore the present PSPICE code is also benchmarked with an implicit tridiagonal solver based on Nakamura's method (BIONAK) again achieving close correlation. The study highlights the excellent potential of both numerical methods described in simulating nonlinear biopolymer micro-structural flows.

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

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=775nm and 387nm) 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.

Ionic Liquid Facilitated Introduction of Functional Materials into Biopolymer Polymer Substrates

In addition to being efficient solvents for biopolymers, several ionic liquids (ILs) have also been to shown to be good solvents for synthetic polymers such as m-aramids, i.e., Nomex ® (1). In this report, m-aramid/cotton composites are created by the partial dissolution of fibrous materials. Composite materials are characterized by scanning electron microscopy (SEM), thermogravimetric analysis (TGA), and flammability testing. Results suggest that the ionic liquid facilitated processes demonstrated are potentially powerful methods to enhancing the flammability characteristics of biopolymers without the denaturation of important native micro and meso structures.

Chirality-Mediated Structure-Properties Relationship in Biomaterials

The phenomenon of the homochirality of life, its origin and implications remains one of the most enigmatic fields of science. It has been shown that homochirality provides necessary control for proper protein dynamics (folding) and is a fundamental basis of selectivity in all biochemical processes. Little is known, though, about the implications of the structural phenomenon of homochirality on the strength, elasticity, and other relevant mechanical characteristics of biopolymers. However, these effects could be profound and lead to significant morphological differences of the resulting biomaterial which is relevant to a number of severe human pathologies.

Cellular response to oxygen containing biomedical polymers modified by Ar and He implantation

Ion beam modification is an attractive way to adapt the response of a biopolymer surface with the view to modifying cellular processes. In this work we performed Ar and He implantations into three oxygen-containing biomedical polymers: polycaprolactone (PCL), poly(ethylene glycol) (PEG) and poly(methyl methacrylate) (PMMA). An ion energy of 25 keV was selected on the basis of singularities observed in simulated implantations. The implantations were carried out with fluences of 5 × 10 13 cm −2 considering also the ion current density as a source of differentiated damage. The modification of the polymer structure and composition was assayed by Fourier transform infrared spectroscopy, which confirmed the selectivity of the ion current density in producing polymer film damage. Biomedical assays denoted lack of structural stability on the PMMA surfaces. Surface analysis of proteins adsorbed from fetal bovine serum on ion-beam-modified PEG were realized by quartz-crystal microbalance with dissipation, which supported the film stabilization and anti-fouling behaviour of the films. On the other hand, protein adsorption studies on micropatterned PCL surfaces were performed by time-of-flight secondary ion mass spectroscopy and revealed a clear enhancement of protein immobilization in ion-beam-modified areas. The response of human mesenchymal stem cells to the surfaces was observed to depend on the biopolymer characteristics, showing adhesion inhibition onto He-modified PEG and specially enhanced colonization onto He-irradiated PCL.

Optical activity of the cellulose acetate-mesophase-generating solvent system in the formation of a lyotropic liquid-crystalline phase

It was demonstrated experimentally that the vapors of a mesophase-generating solvent, i.e., a solvent forming a lyotropic liquid-crystalline phase with a polymer, changed the spatial structure and optical density of natural polysaccharides (cellulose acetates). In this process, the value of specific optical rotation of the polymer modified by the vapors varied in a wide range up to sign inversion. The action of vapors on the polymer follows a peculiar dose-effect pattern, with lower doses producing a stronger effect. Application of this approach to the study into specific structural characteristics of biopolymers, such as DNA, is proposed.