Biopolymer Solutions Research Articles

Brewer's Spent Grain-Cellulose-Coated Copper Electrode-Based Extended Gate Field-Effect Transistor for Nonenzymatic Glucose Detection toward Diagnosis of Diabetes Mellitus.

The demand for environmentally friendly, reliable, and cost-effective electrodes for glucose sensor technology has become a major research area in the paradigm shift toward green electronics. In this regard, cellulose has emerged as a promising flexible biopolymer solution with unique properties such as biocompatibility, biodegradability, nontoxicity, renewability, and sustainability. Because of their large surface area and porous structure, fibrous cellulose substrates quickly adsorb and disperse analytes at detection sites. This work focuses on utilizing glyoxal-treated cellulose (derived from brewer's spent grain (BSG)) for the fabrication of extended gate field-effect transistor (EGFET)-based glucose sensors. This investigation extends to the utilization of BSG-cellulose for glucose detection in biomimicking electrolytes (phosphate buffer saline) to facilitate glucose detection in human blood samples. The fabricated electrode demonstrates a linear range of glucose detection from 1 to 13.5 mM with a Langmuir adsorption coefficient (K) of 0.102. Also, its selectivity toward glucose over interfering molecules such as sucrose, fructose, ascorbic acid, and uric acid under physiological conditions has been demonstrated. This cellulose-based EGFET electrode exhibits a sensitivity of 6.5 μA mM-1 cm-2 with a limit of detection (LOD) of 0.135 mM. Computational studies by density functional theory calculations confirmed the higher binding affinity of glucose molecules with glyoxal-modified cellulose (-0.95 eV) than with pristine cellulose (-0.46 eV). Here, the novelty lies in the fabrication of electrodes with biodegradable catalysts and their integration into the EGFET configuration.

Spinning a Sustainable Future: Electrospun Polysaccharide-Protein Fibers for Plant-Based Meat Innovation.

This study aims to evaluate the feasibility of producing electrospun fibers by combining polysaccharides, zein, and poly(ethylene oxide) (PEO) to simulate the fibers applied in plant-based meat analogs. The rheological properties of biopolymer solutions were evaluated, and the electrospun fibers were characterized according to their morphology, structural interactions, and thermal analysis. The results indicated that the fibers prepared in a ratio of 90:10 of zein/carrageenan from the mixture of a solution containing 23 wt.% of zein with a solution containing 1 wt.% of carrageenan and with the addition of 1 wt.% of PEO presented a promising structure for application as fibers in meat analogs because they have a more hydrophilic surface. Thus, they have good moisture retention. In addition, they have good thermal stability at high temperatures, which is crucial to achieve a consistent and pleasant texture. Furthermore, it was observed that adding zein and PEO helps with the spinnability of the polysaccharides, producing fibers with good homogeneity.

Spreading dynamics of a microgel particle-laden thermosensitive polymer drop along smooth and nanofiber surfaces

The research focuses on the influence of 300-μm microgel particles in an aqueous solution of a thermosensitive biopolymer on the spreading and deformation of 3.7-mm drops. The drops impact a smooth hydrophilic and a rough hydrophobic surface. A mass fraction of microgel particles varies in a range of 0–0.2. A universal physical model of the spreading of thermosensitive polymer drops laden with microgel particles along surfaces with significantly different roughness is proposed. It explains the strong inhomogeneity of the contact line stretching due to the deceleration of the continuous phase flow by microgel particles and the increased flow vorticity because of the addition of the surface roughness factor. The validity of the proposed physical model is proven by qualitative and quantitative assessments of the contact line deformation when spreading. An empirical expression for the maximum spreading factor is derived, taking into account the properties of liquids, wall roughness, and microgel particle concentration; it reliably predicts when Re≈110−3100, the surface roughness is 0.5–125 nm, Ca=4.5×10−7, and the number of microgel particles in drops is up to 100. The expression was successfully tested during the modeling of arbitrary surface roughness and the increased concentration of microgel particles relative to those considered in experiments during the formation of a biopolymer layer. When developing the method of additive manufacturing of a functional layer, a practical correlation was established between the volume content of microgel particles, acting as potential containers for living cells, in a drop and the area of the biopolymer layer.

Drag Reduction by Dried Malted Rice Solutions in Pipe Flow

In this study, the friction factor of a turbulent pipe flow for dried rice malt extract solutions was experimentally reduced to that of a Newtonian fluid. The friction factor was measured for four types of solutions at different culture times and concentrations. The results indicate that the experimental data points of the test solutions diverged from the maximum drag reduction asymptote at and above Re√f ≅ 200~250 and aligned parallel to those of Newtonian fluids. This drag reduction phenomenon differed from that observed in artificial high-molecular-weight polymer solutions, called Type A drag reduction, in which the drag reduction level is dependent on the Reynolds number in the intermediate region. This is classified as a Type B drag reduction phenomenon in biopolymer solutions and fine solid particle suspensions. The order of drag reduction corresponded to approximately 5–50 ppm xanthan gum solutions, as reported previously. Furthermore, the velocity profile in a turbulent pipe flow was predicted using a semi-theoretical equation in which the friction factors were determined using the difference between the experimental results of the tested solutions and Newtonian fluids. The results indicate considerable thickening of the viscous sublayer in the turbulent pipe flow of the test solutions compared with that of Newtonian fluids.

The properties of chitosan and paracetamol in acidic water mixture by viscosity study for pharmaceutical and biomedical applications

ABSTRACT Paracetamol (PC), the active ingredient in Efferalgan, is an effervescent tablet medicine used in the treatment of mild-to-moderate pain. Chitosan (CH) is a biopolymer having immense structural possibilities for chemical and mechanical modifications to generate novel properties, functions and applications, especially in the pharmaceutical area. The dynamic viscosities, η, have been measured, and investigated for the mixture of CH in acidic water and paracetamol aqueous solutions over the entire range of the temperature 20–65°C, and concentrations of 1–10 g/l. The main objective of our research described here was to determine the viscometric properties of biopolymer solutions of CH in PC, as a function of the volume fraction fCH in the CH and PC mixture and temperatures. We identified three main concentration regimes, corresponding to a dilute regime, a critical regime and the semi-dilute regime. Our results showed that the CH/PC is a promising mixture for use in pharmaceutical and antibacterial applications. The chitosan shows antimicrobial activity against various microorganisms, including bacteria.

Competition between Self-Assembly and Phase Separation Governs High-Temperature Condensation of a DNA Liquid.

In many biopolymer solutions, attractive interactions that stabilize finite-sized clusters at low concentrations also promote phase separation at high concentrations. Here we study a model biopolymer system that exhibits the opposite behavior, whereby self-assembly of DNA oligonucleotides into finite-sized, stoichiometric clusters tends to inhibit phase separation. We first use microfluidics-based experiments to map a novel phase transition in which the oligonucleotides condense as the temperature increases at high concentrations of divalent cations. We then show that a theoretical model of competition between self-assembly and phase separation quantitatively predicts changes in experimental phase diagrams arising from DNA sequence perturbations. Our results point to a general mechanism by which self-assembly shapes phase boundaries in complex biopolymer solutions.

Construction of Fu brick tea polysaccharide-cold plasma modified alginate microgels for probiotic delivery: Enhancing viability and colonization

Emerging food processing technologies provide broader avenues for enhancing probiotic delivery systems. In this study, the new Fu brick tea polysaccharide (FBTP) was extracted and combined with cold plasma-modified alginate nano-montmorillonite (AMT) to prepare microgels by ionic gelation to improve the viability of encapsulated Lactobacillus kefiranofaciens JKSP109. Results showed that cold plasma treatment for 3 min changed the surface charge of AMT biopolymer solution, and FBTP addition reduced the particle size to the lowest of 223 ± 5.50 nm. Morphological analysis showed that the AMT treated with cold plasma for 3 min and FBTP (C3AMT + FBTP) formed a dense microgel through electrostatic interaction, and the probiotics were randomly distributed in their internal polysaccharide network, as well as the interlayer and surrounding of nanoparticles. The probiotics immobilized in C3AMT + FBTP microgel exhibited the highest viability (8.48 ± 0.03 log CFU/g) and colonic colonization after exposure to simulated gastrointestinal conditions. In addition, the good antioxidant activity of FBTP reduced the loss of probiotic viability during storage, with only 2.58 log CFU/g decreased after 4 weeks. Therefore, such probiotic products enriched with natural bioactive ingredients can be developed as a potential functional food additive.

Rheological Study on Blend Solutions of Non-mulberry Silk Fibroin and Gelatin Biopolymers

In current research work, we have studied the blending effect of non-mulberry silk fibroin (10% weight/volume basis) and gelatin (20% weight/volume basis) in formic acid. Several blends as SF10G0, SF2G8, SF3G7, SF5G5 and SF0G10 have been made and their rheological behaviour was investigated. The blend solutions were subjected to a steady shear rheological study in the variety of range of shear rates, namely 0.01–500 sec-1 and the viscosities of blend solutions were noticed to decrease in comparison to pure silk solution. The frequency sweep was employed in dynamic rheological tests to determine complex viscosity of these solutions from range of angular sweep 0.1–100 rad/sec. The consistent shear-thinning behaviour was noted for all the blends. The difference in numerical values of shear and complex viscosities indicated disobedience of Cox-Merz rule. Such analysis can be utilised for tailoring the properties of solution prior to processing them to create a versatile range of materials.

Preparation and characterization of pectin-alginate-based microbeads reinforced by nano montmorillonite filler for probiotics encapsulation: Improving viability and colonic colonization

Hydrogel microbeads can be used to enhance the stability of probiotics during gastrointestinal delivery and storage. In this study, the pectin-alginate hydrogel was enhanced by adding montmorillonite filler to produce microbeads for encapsulating Lactobacillus kefiranofaciens (LK). Results showed that the viscosity of biopolymer solutions with 1 % (PAMT1) and 3 % (PAMT3) montmorillonite addition was suitable for producing regular-shaped microbeads. A layered cross-linked network was formed on the surface of PAMT3 microbeads through electrostatic interaction between pectin-alginate and montmorillonite filler, and the surrounding LK with adsorbed montmorillonite was encapsulated inside the microbeads. PAMT3 microbeads reduced the loss of viability of LK when passing through the gastric acid environment, and facilitated the slow release of LK in the intestine and colonic colonization. The maximum decrease in viability among all filler groups was 1.21 log CFU/g after two weeks of storage, while PAMT3 freeze-drying microbeads only decreased by 0.46 log CFU/g, indicating that the gel layer synergized with the adsorbed layer to provide dual protection for probiotics. Therefore, filler-reinforced microbeads are a promising bulk encapsulation carrier with great potential for the protection and delivery of probiotics and can be developed as food additives for dairy products.

Enhancement of electrical conductivity of biopolymer by sulfur nanoparticle dispersion technique

AbstractPresent work reports the investigation of the effect of different percentages of nanosized elemental sulfur particle grown in a biopolymer matrix. Sulfur is known for treatment against bacterial infections as an antimicrobial agent from ages as elemental sulfur and sulfur‐rich compounds interact with biological systems. In‐situ growth of sulfur nanoparticles is processed by the passage of environment friendly hydrogen sulfide gas in hydrated solution of gum acacia biopolymer. Gum acacia is ion conducting, plant derived natural polymer. In this work, structural and morphological studies are examined by x‐ray diffraction and scanning electron microscopy. It is found that with increasing concentration of sulfur nanoparticles the spheroidal shaped nanostructures grow in size and approaches the micron realm. Electrical characterization of the nanostructure synthesized biopolymer is observed by varying frequency over a broad‐spectrum range. Direct current electrical conductivity is found to be enhanced by 40 times higher over pure specimen.

Reduced‐Order Models Unravel the Joint Impact of Aperture Heterogeneity and Shear‐Thinning Rheology on Fracture‐Scale Flow Metrics

AbstractSubsurface industrial operations often make use of complex engineered fluids. In fractured media, the hydraulic behavior of a geological fracture is affected by the shear‐thinning (ST) rheology of such fluids, depending on the imposed pressure gradient. Besides, owing to the stochastic nature of heterogeneities in the fracture's local apertures, obtaining the generic behavior of a fracture under ST flow requires large statistics of fractures whose aperture fields have the same statistical properties, namely their mean value, standard deviation, correlation length Lc, and Hurst exponent (which controls the scale invariances at scales smaller than Lc). The first such Monte Carlo study was recently proposed by Lenci, Putti, et al. (2022) using a new lubrication‐based model relying on a non‐linear Reynolds equation. This model describes the flow of an Ellis fluid, with both a low shear rate quasi‐Newtonian viscosity plateau and a large shear rate power law ST behavior, as measured for engineered fluids such as biopolymer solutions (e.g., xanthan gum). Here we aim to obtain the dependence of the fracture transmissivity and its dispersion over the statistics, as well as of the flow correlation length, on fracture closure, geometry correlation length, and applied pressure gradient, over a vast volume of the parameter space, and in a simple mathematical form. Employing reduced‐order models based on the polynomial chaos expansion theory to this aim, we discuss the properties of the obtained topographies of interest in the parameter space.

Analyzing Local Shear Rate Distribution in a Dual Coaxial Mixing Bioreactor Handling Herschel–Bulkley Biopolymer Solutions through Computational Fluid Dynamics

For the aeration of highly viscous non-Newtonian fluids, prior studies have demonstrated the improved efficacy of dual coaxial mixing bioreactors fitted with two central impellers and a close clearance anchor. Evaluating the effectiveness of these bioreactors involves considering various mixing characteristics, with a specific emphasis on shear rate distribution. The study of shear rate distribution is critical due to its significant impact on the mixing performance, gas dispersion, and homogeneity in aerated mixing systems comprising shear-thinning fluids. Although yield-pseudoplastic fluids are commonly employed in various industries, there is a research gap when it comes to evaluating shear rate distribution in aerated mixing bioreactors that utilize this fluid type. This study aims to investigate shear rate distribution in an aerated double coaxial bioreactor that handles a 1 wt% xanthan gum solution, known as a Herschel–Bulkley fluid. To achieve this goal, we employed an experimentally validated computational fluid dynamics (CFD) model to assess the effect of different mixing configurations, including down-pumping and co-rotating (Down-Co), up-pumping and co-rotating (Up-Co), down-pumping and counter-rotating (Down-Counter), and up-pumping and counter-rotating (Up-Counter) modes, on the shear rate distribution within the coaxial mixing bioreactor. Our findings revealed that the Up-Co system led to a more uniform local shear distribution and improved mixing performance.

Exploiting the prediction of mass transfer performance in aerated coaxial mixers containing biopolymer solutions using empirical correlations and neural networks

AbstractThe volumetric mass transfer coefficient is commonly used to assess the mixing effectiveness of gas–liquid bioreactor systems. Analyzing mass transfer performance in non‐Newtonian fluids inside coaxial mixers can be challenging due to the complex interaction between process variables, which requires developing robust characterization and estimation approaches. This study aims to investigate the gas dispersion in shear‐thinning biopolymers with yield stress using coaxial mixers in order to evaluate the effects of aeration and agitation on the volumetric mass transfer coefficient. A mixing configuration comprising a pitched blade turbine and an anchor was employed to disperse air into xanthan gum solutions, and the mass transfer performance was obtained at different impeller speeds and biopolymer concentrations by measuring the dissolved oxygen concentration. A dimensionless empirical correlation was proposed, and the results showed that the mass transfer was positively influenced by aeration intensity and agitation mechanism, quantified by the gas flow number and Reynolds number, respectively. Additionally, a strategy using stacking‐ensemble artificial neural networks was developed to accurately estimate the volumetric mass transfer coefficient, with a correlation coefficient of 0.998. The proposed mass transfer characterization approach overcame the complexities of analyzing aerated coaxial mixer systems and provided a reliable design model for bioreactor systems containing non‐Newtonian fluids.

8-Oxoguanine-DNA-Glycosylase Gene Polymorphism and the Effects of an Alternating Magnetic Field on the Sensitivity of Peripheral Blood.

The production of reactive oxygen species (ROS) in animals and cells often results from exposure to low-intensity factors, including magnetic fields. Much of the discussion about the initiation of oxidative stress and the role of ROS and radicals in the effects of magnetic fields has centered on radical-induced DNA damage. The DNA concentration in the final solution was determined spectrophotometrically. Typing of the polymorphic variant rs1052133 of the 8-oxoguanin DNA glycosylase (hOGG1) gene was performed by polymerase chain reaction. An enzyme immunoassay was performed to determine the level of 8-oxyguanine in DNA. To process samples exposed to an alternating magnetic field, the authors developed a device for the automated study of biological fluids in an alternating magnetic field. The content of hydrogen peroxide in aqueous solutions of DNA was determined using the spectrophotometric method. It was experimentally determined that an increase in the concentration of hydrogen peroxide in an aqueous medium by 3-5 times under the action of a low-frequency magnetic field reduces the resistance of the genomic material to oxidative modification and the accumulation of 8-oxyguanine in DNA. A model is proposed for the mechanism of action of a low-frequency magnetic field on aqueous solutions of nucleic acids and proteins, which satisfies the model of a chemical oscillator for the transformations of reactive oxygen species in an aqueous medium. The model illustrates the oscillating nature of the processes occurring in an aqueous solution of DNA and makes it possible to predict changes in the concentration of hydrogen peroxide in an aqueous solution of biopolymers, depending on the frequency of the acting low-intensity magnetic field. The key element in the mechanisms involved in the effects of low-intensity magnetic field on living systems is the occurrence of ROS generation in the aquatic environment of chemical oscillators, in which the competition of physical and chemical processes (electron transfers, reactions of decay and addition of radicals, spin magnetically induced conversion, synthesis, and decay of the longest-lived form-hydrogen peroxide) is controlled by a magnetic field.

Mechanism of action of the low-frequency electromagnetic field on aqueous solutions of biopolymers

This paper presents the mechanism of signal transformation by which a signal from the magnetic component of the low-frequency electromagnetic field with extremely low energy is changed into chemical and biochemical signals which elicit a biological response in aqueous solutions of biopolymers based on nucleic acids and proteins. A theoretical model developed shows that the basis of oxidative DNA damage and conformational transitions of proteins is a universal mechanism associated with a change in the amount of the most long-lived form - hydrogen peroxide in a chemical oscillator of mutual transformations of reactive oxygen species under the influence of low-intensity electromagnetic field exposure. It has been experimentally established that the quantitative content of hydrogen peroxide in solutions of biopolymers resonantly depends on the frequency of applied field. Conformational changes in proteins are accompanied by an increase in the availability and activity of the nucleophilic centers that are potential targets for reactive oxygen species. Complete unfolding and denaturation of the amino acid chain of the protein under the influence of low-frequency electromagnetic field exposure do not occur. It has been shown that enhanced hydrogen peroxide formation at 3 Hz and 50 Hz leads to oxidative modification of nitrogenous bases in DNA.

Mechanism of Action of the Low-Frequency Electromagnetic Field on Aqueous Solutions of Biopolymers

Mechanism of Action of the Low-Frequency Electromagnetic Field on Aqueous Solutions of Biopolymers

Natural Biopolymer–Hydrogel Nanofibers for Antibacterial Applications

Abstract This study used a suitable solvent such as deionized water and aqueous acetic acid to dissolve completely polymer blends such as gelatin: chitosan: pullulan (G: CS: PUL) with mixing ratios of 80:10:10, 60:20:20, 40:30:30, and 20:40:40, respectively. The properties of natural polymer mixtures, viscosity, surface tension, and electrical conductivity were examined, and the fiber diameter and nanofiber diameter distribution were measured. Increasing the gelatin content from 20% to 80% in the G: CS: PUL increases the properties of biopolymer solutions, such as viscosity, surface tension, and electrical conductivity of 157%, 14%, and 37%, respectively. In addition, increasing the gelatin content reduces the contact angle by 55%. In other words, the average diameter of the nanofibers increased from 91.177 ± 27.162 to 212.46 ± 67.91 nm with the increase of the gelatin content by 40–100% in the blends and obtaining uniform fibers without beads, which enhanced the ability of nanofibers for releasing into the aqueous media and enhancing their use in packaging food such as (80:10:10 and 60:20:20). Moreover, the blend ratio 60:30:30 (G:CS: PUL) had better resistance to bacterial growth; the inhibition zone diameters were 26 and 23 mm for E. coli and S. aureus and had better average crystalline size and crystallinity.

Carboxymethyl Chitosan Hydrogels for Effective Wound Healing-An Animal Study.

Hydrogels have various applications in medicine, for example, in systems for controlled drug release or as wound dressings, where they provide an appropriate environment for healing and constitute a barrier to microorganisms. The aim of this study was to evaluate the action of carboxymethyl chitosan (CMCS) hydrogels in wound healing therapy in vivo using a laboratory rat model. The hydrogels were formed from aqueous solutions of a CMCS biopolymer via electron beam irradiation, with the presence of a crosslinking agent of poly(ethylene glycol) diacrylate. A histopathological examination of injured tissue, using a model of a hard-to-heal wound, indicated that the CMCS hydrogel supported healing. The new gel dressing, being noncytotoxic, presents great potential in wound treatment, with positive effects on the amount of inflammatory infiltration, young collagen formation, and the degree of epidermalization. A key advantage of the current approach (i.e., using competitive radiation technology for synthesis) is that it includes only one step, with the product being sterilized as it is synthesized. The hydrogel effectively supports wound healing and can serve as a bio-based and biodegradable platform for other medical applications.

Stability and cytotoxicity of biopolymer-coated liposomes for use in the oral cavity

This study investigates the stability and cytotoxicity of biopolymer-coated liposomes for use in the oral cavity. Liposomes (3 mM and 6 mM) were prepared by the thin film method and hydrated with phosphate buffer (PB) or glycerol phosphate buffer (G-PB). For coating, liposomes were added to a biopolymer solution of opposite charge. Particle stability was evaluated by measuring the size, polydispersity index, and zeta potential for up to 60 weeks. In vitro interaction of fluorescent-labelled biopolymer-coated liposomes and dysplastic oral keratinocytes was analyzed by confocal microscopy. Potential cytotoxicity was assessed in dysplastic oral keratinocytes by cell proliferation and cell viability. All three biopolymers showed good coating abilities for both concentrations and hydration media. The alginate coated liposomes in PB, 3 mM chitosan-coated liposomes in PB, and chitosan-coated liposomes in G-PB were stable for up to 60 weeks. In vitro studies demonstrated low cytotoxicity for all coated liposomes and non-specific cellular uptake of biopolymer-coated liposomes, independent of biopolymer, surface charge, lipid concentration and hydration media. All three formulations demonstrated low cytotoxicity and were considered safe. Alginate- and chitosan-coated liposomes demonstrated good stability over time and may be promising agents for use in the oral cavity and should be investigated further.

Enhanced Methane Hydrate Formation Kinetics in Frozen Particles of Biopolymer Solutions: Applicable to Methane Storage

Enhanced Methane Hydrate Formation Kinetics in Frozen Particles of Biopolymer Solutions: Applicable to Methane Storage