Aqueous Polysaccharide Solutions Research Articles

Construction and antibacterial activities of walnut green husk polysaccharide based silver nanoparticles (AgNPs)

In this paper, the size-controllable nano‑silver particles (AgNPs) were synthesized from walnut green husk polysaccharide, and its cytotoxicity and antibacterial activity were evaluated. Firstly, acidic polysaccharide WGHP2 was extracted from walnut green husk, and then the silver ion in AgNO3 was reduced in WGHP2 aqueous solution using NaBH4, so as to synthesize the nano‑silver composite. The nano‑silver composite was characterized by transmission electron microscope, Fourier infrared spectroscopy, ultraviolet-visible spectrometer, scanning electron microscope, inductively coupled plasma mass spectrometry and X-ray photoelectron spectroscopy. The results show that AgNPs stabilized by WGHP2 are mainly regular spheres with an average particle size distribution of 15.04–19.23 nm. The particle size distribution and morphology of AgNPs changed with the concentration of silver precursor, which is related to the dispersion of silver precursor in polysaccharide aqueous solution and the formation of AgO coordination bond between silver precursor and polysaccharide molecules. These coordination bonds changed the ability of nanoparticles to produce and release Ag+, and thus regulated their antibacterial activity and cytotoxicity, as evidenced by the experimental result of the cytotoxicity of the nano‑silver particle against PC12 cells and the bacteriostatic effect on E.coli and S.aureus. Conclusively, WGHP2-Ag has good stability, antibacterial activity and low cytotoxicity.

An Innovative Methodology to Characterize, at the Molecular Scale, Interactions in Polysaccharide Aqueous Solutions.

Characterizing molecular interactions at the microscopic level remains difficult and, therefore, represents a key target to better understand macromolecule and biomacromolecule behaviors in solution, alone, or in mixtures with others. Therefore, accurate characterization in liquid media, especially in aqueous solutions, without causing any perturbation of the system in which they are studied, is quite difficult. To this purpose, the present paper describes an innovative methodology based on fluorescence spectrophotometry. Two molecular fluorescent probes, namely 8-anilino-1-naphtalenesulfonic acid (ANS) and 2-benzofuryl-3-hydroxy-4(1H)-quinolone (3HQ-Bf), were selected to characterize, respectively, the dipole-dipole interactions and hydrophobic micro-domains, for the first one, and hydrogen bonding, for the second. As a support to study molecular interactions, xanthan, galactomannan, and corresponding mixtures of these substances which are well known to exhibit a synergy of interactions in well-defined mixture conditions were chosen. Once the methodology was set up, the existence of the three types of interactions in these systems was demonstrated, thus allowing the elucidation of the mechanisms of interactions at the molecular scale.

Clinical Applicable Carboxymethyl Chitosan with Gel-Forming and Stabilizing Properties Based on Terminal Sterilization Methods of Electron Beam Irradiation.

Carboxymethyl chitosan (CMC)-based hydrogels have great potential for clinical applications, but a critical sterilization process must be addressed to bring them to market. Compared to ethylene oxide sterilization or heat sterilization, irradiation sterilization avoids alkylation and heat damage, while available studies on γ-irradiated other polysaccharides show that solution polysaccharides are susceptible to degradation or cross-linking. Aiming at the challenges brought by the γ-irradiation process of polysaccharide aqueous solution, this paper innovatively proposes the lyophilized CMC using electron beam (EB) irradiation, which not only avoids the generation of free radicals in the irradiated water leading to the degradation and cross-linking of polysaccharides but also retains the properties of CMC in terms of gel formation, stabilization, and clinical application. We used FTIR, TG, GPC, and microbial load tests to demonstrate that lyophilized CMC did not have significant changes in structure and molecular weight after EB irradiation, complied with the requirements for sterilization, and still had gel stability, thus proving that lyophilized CMC could be used for EB irradiation and met the requirements for clinical application. Therefore, this work is expected to further advance CMC injectable hydrogels toward clinical applications and provide a new direction for the sterilization processes of other polysaccharide hydrogels.

First derivative, extrapolation, and deconvolution of the complex conductivity data for the identification of the optimum entanglement concentration of polysaccharides in aqueous solutions

First derivative, extrapolation, and deconvolution of the complex conductivity data for the identification of the optimum entanglement concentration of polysaccharides in aqueous solutions

Characteristics of mucous-forming polysaccharides extracted from flax seeds

The research used the seeds of long flax of the "Vruchy" variety and oil-curly flax of the "Original" variety. To extract mucus, whole flax seeds were hydrated for 3 hours. in tap water, at a ratio of 1:20 and a temperature of 18 – 20 °C with constant stirring with a magnetic stirrer. This study aimed to evaluate the effect of temperature and duration of extraction on the yield of mucilaginous polysaccharides in aqueous solution from flaxseed. Change range: the temperature is selected in the range from 0 °С to 100 °С with a step of 20 °С; with a duration, ranging from 10 min to 140 min in 10 min increments. The yield of polysaccharides from flax seeds was determined for each combination of controlled factors. It was established that in the first 10 – 20 min. there is an increase in the yield of polysaccharides and the rate slows over time. For 90 min. equilibrium occurs at a temperature of 80 °C. This period of the process is optimal for the extraction of mucilage-forming polysaccharides from flaxseed. The mass of the extracted polysaccharides, from the mass of the seeds after a time of 95 min was 5.74%, and 6.00% at a temperature of 80 °С. A package of applied statistical programs was employed during the research to process the experimental data. A mathematical model of the process of extracting mucus-forming polysaccharides in an aqueous solution of flax seeds was built using regression analysis methods. The obtained regression equations determined the optimal regimes of the sought values in terms of temperature (80 – 85 °C), time (85 – 90 min) and conducted in compliance with the prescribed amount of water of 200 cm3. Within 10 – 20 min the formation of a transparent gel capsule around the flax with a phase separation boundary under seed contact with water, which does not change further. This indicates the completion of the hydration process.

Rheological properties and thickening effect of high molecular weight exopolysaccharide and intracellular polysaccharide from Schizophyllum commune

Edible and medicinal fungal polysaccharides with excellent biological activity and high viscosity are potential thickeners for food applications. In this study, the rheological properties of aqueous solutions of exopolysaccharide or fermentation broth polysaccharide (SCFP) and intracellular polysaccharide or mycelial polysaccharide (SCMP) obtained from liquid submerged fermentation of the fungus Schizophyllum commune (S. commune), and their thickening effects on coffee and fruit tea were investigated. The polysaccharide aqueous solutions behaved as pseudoplastic fluids, and their viscosity was concentration-dependent but not significantly affected by temperature (10–70 °C). The critical concentrations (c*) of SCFP and SCMP were 0.275 g/L and 0.356 g/L, respectively. The intensity of the thixotropic properties of the polysaccharide aqueous solutions was positively correlated with polysaccharide concentration. Both polysaccharide solutions exhibited solid-like viscoelastic behavior and formed weak gels, with enhanced gel strength at high concentrations and low temperatures. The viscosity at a shear rate of 50 s−1 (η50) of the 5 g/L SCFP- and SCMP-thickened coffee was 0.07 Pa·s, while that of SCFP- and SCMP-thickened fruit tea was 0.1 Pa·s and 0.08Pa·s, respectively, which were significantly higher than that of polysaccharide aqueous solutions (0.05 Pa·s for SCFP and SCMP). The yield stress values increased with increasing polysaccharide concentration, suggesting a potential role of for these polysaccharides in dysphagia management. Overall, SCFP and SCMP have significant potential for application in the food industry.

Structure, anticoagulant and cytotoxic activity of a sulfated polysaccharide from green seaweed Chaetomorpha linum

In this article, chemical structure and conformation in an aqueous solution of a new sulfated polysaccharide, PCL, extracted from green seaweed Chaetomorpha linum were elucidated by SEC-MALL, IR, NMR and SAXS. The results indicated that the obtained polysaccharide is a sulfated arabinogalactan with a molecular weight of 223 kDa, and is mainly composed of →3,6)-α-D-Galp4S→ and →2)-α-L-Araf→ connecting together through 1→3 glycoside linkages. It has a broken rod-like conformation in solution with Rgc estimated as 0.43 nm from SAXS measurements. The polysaccharide exhibited a notable anticoagulant activity measured by the assays of activated partial thromboplastintime, thrombintime and prothrombine time as well as a significant cytotoxic activity against hepatocellular, human breast cancer, and cervical cancer cell lines.

A new approach based on the combination of complex impedance and conductivity to investigate the interaction mechanisms of raw polysaccharides in aqueous solutions

The molecule-water and molecule–molecule interactions are the main keys to understanding the behavior of polysaccharides in an aqueous solution. In this work, electrical impedance spectroscopy is used to investigate raw polysaccharides' dielectric and electrical properties. Impedance data were carried out for different concentrations in the frequency range [10-2–106Hz] and then analyzed in Nyquist and bode representation, revealing one clear maximum due to the electrode polarization. Therefore, the complex conductivity is analyzed and makes the other relaxation processes very clear.Moreover, an appropriate equivalent circuit was developed, showing good agreement with the experimental data. The extrapolation and deconvolution approaches in the frequency range [10-3–107Hz] were performed to confirm the presence of the three relaxation processes and the validity of the equivalent circuit. The first was attributed to the electrode polarization, and the other processes were attributed to the molecules-water and molecule-counterion interactions. Finally, a clear transition at 5% (w/v) is shown in the evolutions of the conductivity, suggesting the transition from the dilute to the semi-dilute domain.

Real-time monitoring of enzymatic hydrolysis of 1,3(4)-β-glucan with high-resolution ultrasonic spectroscopy

The paper describes the application of High-Resolution Ultrasonic Spectroscopy for real-time, non-destructive, precision monitoring of enzymatic hydrolysis of polysaccharides in aqueous solutions, represented by barley 1,3(4)-β-D-glucan. The technique provided time profiles of the concentration of glycosidic bonds hydrolyzed, degree of hydrolysis, average degree of polymerization, and molar mass of hydrolysates produced. The limiting precision of the technique in measurements of the concentration of glycosidic bonds hydrolyzed is at the level of 0.01 mmol kg−1. The Michaelis constant Km for the enzyme employed, endo-1,3(4)-β-d-glucanase from Talaromyces emersonii, calculated from the ultrasonic reaction profiles was 0.061 mol L−1 at 50 °C, in 0.1 mol L−1 NaOAc buffer, pH 5.0 at 50 °C. The Mark-Houwink parameter a of the polysaccharide hydrolysates, obtained from correlation of ultrasonically measured evolution of average molar mass and of viscosity, was 0.63.

Structural elucidation of a novel polysaccharide from Ophiopogonis Radix and its self-assembly mechanism in aqueous solution

Ophiopogonis Radix polysaccharides with various bioactivities have caught people's attention in the pharmaceutical and functional food industries. It is necessary to reveal their structures, chain conformations, and solvent behaviors. A neutral polysaccharide named ORP-1 with molecular weight of 3667 Da was obtained from Ophiopogonis Radix. It was composed of d-fructofuranose and d-glucopyranose in the ratio of 0.85:0.15. Methylation, FT-IR and NMR analysis indicated ORP-1 consisted of 2,6-linked-Fruf units as the main chain and 1-linked-Glcp residue at the end. Congo red assay showed ORP-1 had no triple-helix structure. The observation of TEM and AFM found ORP-1 could self-assemble to form colloidal aggregate in water. This phenomenon was verified using CMC determination and MD simulation. Furthermore, intermolecular hydrogen bonds and hydrophobic interactions would be the main forces driving the aggregate. These results provided reference for the study of the chain conformation and behavior of polysaccharides in aqueous solution.

Comparative characterization of sugar beet fibers to sugar beet pectin and octenyl succinic anhydride modified maltodextrin in aqueous solutions using viscometry, conductometry, tensiometry and component analysis.

Knowledge about specific functional characteristics, such as viscosimetric, conductometric, tensiometric and structural properties of polysaccharide aqueous solutions is highly important in the successful and adequate application in food emulsion formulation. For the first time detailed characterization of sugar beet fibers aqueous solutions in comparison to high molecular weight (sugar beet pectin) and low molecular weight [octenyl succinic anhydride (OSA) maltodextrin] hydrocolloids/stabilizers was performed through viscometry, conductometry, tensiometry and component analysis. Sugar beet fibers and its water-soluble fraction were investigated. All sugar beet fiber samples showed substantial surface-active properties but different effect on the viscosity values of aqueous solutions. Sugar beet pectin had higher impact on aqueous solutions viscosity values compared to sugar beet fiber samples. Structural bonding between investigated polysaccharides were evaluated through conductometric measurements. Intermolecular linking and probable embedding of OSA maltodextrin molecules into the sugar beet fiber complex structure was detected in conductometric studies. The increased concentration of sugar beet fibers in the presence of sugar beet pectin led to the accelerated increase in specific conductivity values indicating effects of 'macromolecular crowding', intermolecular and intramolecular conformation changes and charge formation. Detailed characterization of sugar beet fibers provided scientific insight towards fundamental characteristics of sugar beet fiber aqueous solutions. The presented characteristics are particularly applicable in the field of food emulsion stabilization due to the presented surface-active properties of sugar beet fibers as well as specific characteristics of investigated multi-polysaccharide systems. © 2022 Society of Chemical Industry.

Micellar structure of hydrophobically modified polysaccharides in aqueous solution

This article reviews previous studies on micellar structures formed by hydrophobically modified polysaccharides in aqueous solutions by static and dynamic light scattering, small angle X-ray and neutron scattering, and fluorescence from pyrene solubilized in polymer solution. The experimental results are consistently explained by the full or loose flower necklace model for pullulan bearing octenyl groups and amylose bearing dodecyl groups and by the randomly branched polymer model, which is often called a “nanogel”, for pullulan bearing cholesteryl groups. We discuss the micellar structures of hydrophobically modified polysaccharides as well as of an amphiphilic alternating vinyl polymer bearing dodecyl groups in regard to the degree of substitution as well as the chemical structures of the hydrophobic moiety and backbone chain.

Cryophylactic Solution Based on Pectic Oligosaccharides for the Creation of New Dosage Forms

For the first time in a wide temperature range, the rheology of aqueous solutions of oligo-and polysaccharides obtained by the method of combined fractionation from the secondary phytomass of apple pomace and albedo pomelo has been studied. The values of the freezing point have been determined and the possibility of the practical use of oligosaccharides as components of special-purpose preparations in liquid dosage form has been shown. On the basis of oligosaccharides obtained by the method of combined fractionation from the secondary phytomass of apple pomace and albedo pomelo, cryophylactic media have been created for the first time, possessing physicochemical stability in a wide temperature range. The main rheological and temperature characteristics of the obtained compositions have been studied and the possibility of the practical use of oligosaccharides as components of medical preparations for special purposes in liquid dosage form has been shown.

UV Detection and Avoidance of Protein in Basella alba leaf Mucilage Polysaccharide by differential precipitation

Objective: In the aim of refining mucilage polysaccharide extracted from the leaf of Basella alba, extraction and differential precipitation of the protein content was studied. This was attempted by pH adjustment by adding Trichloroacetic acid (TCA) and Hydrochloric acid (HCl). Materials and Methods: The presence of residual protein before and after deproteinization in the polysaccharide solution was detected by UV spectrum analysis. The % polysaccharide, % polysaccharide loss, protein concentration and the deproteinization efficiency were studied as comparative indices to evaluate the precipitation experimental conditions using pH adjustment. Results: The result showed that 10% w/v TCA precipitated over 80% of the protein when the pH of the aqueous polysaccharide solution was 3. Discussion: TCA was proved to be superior to hydrochloric acid as evidenced by the highest deproteinization efficiency (83.3%). The polysaccharides of all the extracted solutions obtained were identified with only slight variations in percentage. The Hcl method excelled over the TCA method in obtaining polysaccharides with little lower percentage of polysaccharide loss (13.94 %). Conclusion: The TCA method will offer a room for deproteinization of polysaccharides if optimization is studied.

Structure Formation as a Method of Forming Physicomechanical Characteristics of Films Obtained from Aqueous Solutions of Certain Polysaccharides

The aqueous solutions of chitosan, succinyl chitosan sodium salt, and carboxymethylcellulose sodium salt are studied by the rheological method. An increase in the polymer concentration in solution leads to a sharp increase in viscosity due to formation of the entanglement network, the transition of the polymer solution to the gel-like state, a sharp increase in the relaxation time, and the appearance of elasticity of solutions. These systems are characterized by time anomalies characterized by a hysteresis loop, the area of which depends not only on concentration but also on the rate of increase/decrease of the shear rate. Thixotropy is observed in the intermediate concentration range, where supramolecular structures are formed and the time required for their destruction is comparable to the time of the experiment. This makes it possible to regulate a number of properties of materials formed from solutions. According to DSC studies, the glass transition temperatures and the melting temperatures of films obtained from solutions of different concentrations are different. The tensile stress and the elastic modulus of film polymeric materials pass through a maximum corresponding to the polymer concentration at which the maximum degree of structuring is implemented while maintaining the fluidity.

Viscosity of Aqueous Polysaccharide Solutions and Selected Homogeneous Binary Mixtures

The viscosity (η) of dextran (Dex), methyl cellulose (MC), hydroxypropylmethyl cellulose (HPMC), κ-carrageenan (KC), alginate (Alg), and carboxymethyl cellulose (CMC) was measured as a function of the shear rate (γ̇) over a broad range of concentrations both in salt-free water and in 0.1 M NaCl. The concentration (C) dependence of the Newtonian viscosity (η0) was found to be universal for neutral polysaccharides and anionic polysaccharides in 0.1 M NaCl when C was multiplied with the intrinsic viscosity. The dependence was compared with theoretical predictions assuming dominant hydrodynamic or dominant topological interactions. The effect of electrostatic interactions was observed for anionic polysaccharides in salt-free water but not at higher concentrations. Master curves of the shear thinning behavior at different concentrations were obtained when η/η0 was plotted versus τ. γ̇, with τ being a concentration-dependent time that characterizes the onset of shear thinning. Binary mixtures of two neutral polysaccharides (MC and HPMC), two anionic polysaccharides (Alg and CMC), and a neutral (Dex) and anionic polysaccharide (KC) were investigated as a function of the composition and the total polysaccharide concentration. The behavior of the first two mixtures was similar to that of a single polysaccharide with an intermediate intrinsic viscosity. Significant synergy was observed for the third type of mixtures in salt-free water demonstrating the important effect of electrostatic interactions between charged polysaccharides at low concentrations even in concentrated solutions of neutral polysaccharides.

Hyaluronic Acid: The Influence of Molecular Weight on Structural, Physical, Physico-Chemical, and Degradable Properties of Biopolymer.

Hyaluronic acid, as a natural linear polysaccharide, has attracted researchers’ attention from its initial detection and isolation from tissues in 1934 until the present day. Due to biocompatibility and a high biodegradation of hyaluronic acid, it finds wide application in bioengineering and biomedicine: from biorevitalizing skin cosmetics and endoprostheses of joint fluid to polymeric scaffolds and wound dressings. However, the main properties of aqueous polysaccharide solutions with different molecular weights are different. Moreover, the therapeutic effect of hyaluronic acid-based preparations directly depends on the molecular weight of the biopolymer. The present review collects the information about relations between the molecular weight of hyaluronic acid and its original properties. Particular emphasis is placed on the structural, physical and physico-chemical properties of hyaluronic acid in water solutions, as well as their degradability.

Power Laws Dominate Shear and Extensional Rheology Response and Capillarity-Driven Pinching Dynamics of Entangled Hydroxyethyl Cellulose (HEC) Solutions

Quantitative studies of capillarity-driven pinching and extensional rheology of aqueous solutions of polysaccharides like hydroxyethyl cellulose (HEC) are beyond the measurable range of most extens...

Effects of κ-carrageenan on pullulan’s rheological and texture properties as well as pullulan hard capsule performances

κ-Carrageenan (κ-Ca) is often used to facilitate gelling of aqueous solutions of polysaccharides. However, studies on its effects on pullulan’s rheological and texture properties and pullulan (PUL) hard capsule performances have rarely been reported. Herein, effects of κ-Ca on PUL solutions, hydrogels, films and hard capsules were investigated. It was found that the gelling temperature of 15 % (w/w) PUL solutions with 0.07 % KCl increased from 34 ℃ to 42 ℃ as the concentration of κ-Ca increased from 0.6 % to 1.2 %, and the gelling temperature rose from 25 ℃ to 37 ℃ by adding a small amount of KCl (0.07 %) for 15 % PUL solutions with 0.9 % κ-Ca. As the κ-Ca concentration increased, hardness, fracturability and adhesiveness rose for PUL gels and tensile stress increased for PUL films. PUL capsules could be easily prepared by the aid of κ-Ca, and performances of capsules could be adjusted by changing the amount of κ-Ca.

Potential applications of Abelmoschus moschatus polysaccharide as colon release tablets-Rheology and gamma scintigraphic study

In the present scenario of pharmaceutical development, researchers are focusing on the herbal excipients for different delivery systems. This work describes diverse characteristics of novel polysaccharide extracted from the stem of Abelmoschus moschatus (AM). Further, polysaccharide was explored for its potential role as polymer in controlling colon-specific release of metronidazole (MNZ). Cell toxicity study confirmed its safety aspects in biological applications. The aqueous solution of polysaccharide exhibited non-Newtonian pseudoplastic flow property. The consistency coefficient (k) was found to increase with increase in concentration and particle size of AM polysaccharide. Viscosity was found to increase by increasing pH of the aqueous solution of AM. In-vivo gamma scintigraphy study of radiolabeled MNZ tablet in human volunteers confirmed small intestinal transit time of 300–480 min and colon arrival time of 360–480 min. The present study revealed that AM polysaccharide may be a choice of pharmaceutical excipients as an alternative to synthetic polymers.