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In this study, response surface methodology (RSM) was carried out with four parameters: chitosan concentration, AgNO3 concentration, ascorbic acid concentration and time with the objective to obtain minimum mean particle size of silver nanoparticles (response Y). The chitosan-silver nanoparticle composite material (CTS-AgNPs nanocomposite) obtained experimentally from the optimal conditions was characterized by evaluating some of their physical-chemical properties using combined technique including visible ultraviolet spectroscopy (UV -Vis), dynamic light scattering (DLS), transmission electron microscopy (TEM), infrared spectra (IR) and X-ray diffraction. The optimal conditions were chitosan concentration of 19.2 %, silver nitrate of 26 mM, ascorbic concentration of 33 mM and time of 4.25 hours. Spherical Ag particles obtained experimentally were well dispersed in chitosan matrix with the average diameter of around 2÷8 nm with a narrow size distribution and homogeneous dispersion

A facile “green chemistry” hydrothermal method of chitosan-Ag nanoparticles (NPs) synthesis has been proposed. Chitosans of different molecular weight (from 20 to 1200 kDa) have been used as reducing agents and particle stabilizers. The obtained chitosan–Ag nanocomposites have been studied by UV–Vis and IR spectroscopy, X-ray powder diffraction analysis, and transmission electron microscopy. Nanocomposites have a “core-shell” structure, spherical shape with size up to 60.0 nm and the surface ξ-potential value >40.0 mV. Optimal parameters of synthesis (time, temperature, molecular weight of chitosan) of chitosan–Ag nanoparticles with highest antimicrobial activity against gram-positive and gram-negative bacteria and fungi have been found.

In this study, novel phase-separated composite films based on poly(vinyl alcohol) (PVA) and chitosan lactate (CL) were prepared by the solvent casting method. The influence of varying concentrations of CL (2.5–10% w/w) on the physicochemical properties of the films was assessed. Bright-field micrographs showed the formation of phase-separated polymeric matrices of different architectures in the CL concentration range of 2.5 and 7.5 wt%. At 10 wt% of CL, a homogenous matrix of polymer blend was observed. The developed films demonstrated excellent shielding properties against UV and visible radiation. FTIR studies confirmed the presence of hydrogen bonding between the parent polymers, i.e., PVA and CL, of the films. The film containing 7.5 wt% CL exhibited the highest crystalline nature with little crystal imperfections as compared to the remaining films. Impedance spectroscopy confirmed the conductive nature of the prepared films. The thermograms revealed that the addition of CL strongly influenced the hydrophilic interactions between the functional groups of the polymer components and the water molecules. PVA/CL composite films showed a higher % release of ciprofloxacin HCl (CPH) as compared to the pristine PVA film. CPH-loaded films showed excellent antimicrobial efficacy against model organisms. Therefore, the novel PVA/CL phase-separated composite films can potentially be used as matrices for UV-shielding and drug delivery applications.

Сhitosan-ferulic acid conjugates were synthesized by carbodiimide method and characterized by UV and FTIR spectroscopy. It has been determined that by varying the ratio of components during synthes...

In this study, degraded polysaccharides from Sargassum fusiforme (PSF-T2) were prepared by UV/H2O2 treatment for 2 h, and its effects on ameliorating dextran sulfate sodium-induced colitis were evaluated using a mouse model. Results showed that PSF-T2 relieved colitis symptoms, characterized by increasing the colon length and body weight, decreasing disease activity index and relieving colon damage. In addition, PSF-T2 decreased the secretion and expression of IL-1β, IL-6 and TNF-α, and increased the expression of MUC-2, ZO-1 and occludin. Besides, PSF-T2 promoted the production of short-chain fatty acids and modulated gut microbiota composition (increasing the abundance of Lactobacillaceae, Lachnospiraceae, Oscillospiraceae and Desulfovibrionaceae, and decreasing Bacteroidaceae and Erysipelotrichaceae). These results suggested that polysaccharides from Sargassum fusiforme after UV/H2O2 degradation could ameliorate colitis by decreasing inflammation, protecting the intestinal barrier and modulating gut microbiota. It can provide a theoretical basis for the preparation of bioactive polysaccharides by free radical degradation.

The design of novel wound dressings for chronic wound treatment is still of great importance. One of the promising approaches is application of mesenchymal stem cells (MSCs), immobilized on a flexible polymer film, for healing. In this study, blended films based on polyvinyl alcohol (PVA) and pectin with different component ratio have been prepared by solution casting method and evaluated. Physicochemical properties of the formed PVA/pectin films, including their morphology, wettability, swelling, stability, mechanical characteristics, have been studied. We demonstrated that the surface of PVA/pectin films could be modified by ultraviolet or dielectric barrier discharge plasma exposure. After both ultraviolet and plasma treatment, the hydrophilicity of PVA/pectin films increased. It has been shown that additional crosslinking of PVA/pectin films with glutaraldehyde resulted in reinforcement of their structure. MSCs were cultured on neat and modified PVA/pectin samples to evaluate the effects of film characteristics and composition on cell behavior. It has been determined that MSCs effectively adhered to glutaraldehyde-crosslinked PVA/pectin films and formed on them the monolayer culture of fibroblast-like cells. The additional modification of PVA/pectin films with collagen resulted in enhancement of MSCs adhesion. Our results show that the obtained PVA/pectin films with adhered MSCs can be suggested for potential application as a part of novel complex wound dressings.

In this study, a purified algal polysaccharide (P1) was isolated from Sargassum fusiforme and its structural characteristics and anti-photoaging activity were studied. Results showed that P1 had a molecular weight of 289 kDa and was mainly composed of mannuronic acid, guluronic acid and fucose with molar ratio of 7.67:2.35:1.00. The backbone of P1 was →4)-β-ManA-(1→4)-α-GulA-(1→4)-β-ManA-(1→4)-β-ManA-(1→4)-α-GulA-(1→4)-β-ManA-(1→3,4)-β-ManA-(1→ with a terminal group of α-Fucp-(1→ linked to O-3 position of →3,4)-β-ManA-(1→. In addition, P1 could inhibit the expressions of MMPs (MMP-1, MMP-3 and MMP-9) in the UVB-irradiated HaCaT cells, indicating that P1 could reduce collagen loss caused by UVB irradiation. It also reduced the contents of ROS and inflammatory factors (TNF-α, IL-6 and IL-1β), indicating that P1 could reduce the oxidative stress and inflammation response. Thus, Sargassum fusiforme polysaccharide P1 could be used as a potential functional food to relieve skin photoaging.

Positively charged (zeta potential 22-31 mV) hydrogel microparticles based on low and high molecular weight chitosan were synthesized. The effect of the crosslinking agent on their physicochemical characteristics was studied. It was established, that among obtained hydrogel particles, the ones based on low molecular weight chitosan crosslinked with citrate anions, followed by additional treatment with glutaraldehyde, are the most promising as carriers of growth regulators or plant protection products.

Hydrogel negatively charged (–13.5 ± 5.0 mV) calcium pectinate nano- and submicroparticles (50–150 nm) were obtained. A technique for entrapment of a plant growth regulator (trans-cinnamic acid) in the particles up to 40 wt. % has been developed. It has been established that the complete release of trans-cinnamic acid in the Murashige–Skoog medium takes 2.5 hours. The obtained particles of calcium pectinate do not affect the growth processes of cells in suspension culture and can be used as neutral carriers for growth regulators.

The calcium pectinate hydrogel particles with an average diameter of 100.0 ± 50.0 nm were synthesized by ionotropic gelation method. The possibility of incorporating of trans-cinnamic acid plant growth regulator into them up to 56.3 wt % was shown. The obtained calcium pectinate particles, including those containing a plant growth regulator, were characterized by transmission electron, atomic force microscopy, and IR spectroscopy. It has been shown that calcium pectinate particles containing trans-cinnamic acid contribute to the accumulation of photosynthetic pigments in the treatment of corn seeds.

In this study, the degraded purified fraction from Sargassum fusiforme polysaccharides (SFP), named DSFP, was produced by the treatment of ultraviolet/hydrogen peroxide (UV/H

In this study, degraded polysaccharides from

Implant-related infection is one of the serious problems in regenerative medicine. Promising approach to overcome the problems caused by bacterial growth on the medical implants is their modification by bioactive coatings. A versatile technique for designing multilayer films with tailored characteristics at the nanometer scale is layer-by-layer assembly. In this study, multilayer films based on biopolymers (pectin and chitosan) and their nanocomposites with silver nanoparticles have been prepared and evaluated. The buildup of multilayers was monitored using the quartz crystal microbalance with dissipation technique. The morphology of the obtained films was investigated by atomic force microscopy. We have demonstrated that pectin-Ag-containing films were characterized by the linear growth and smooth defect-free surface. When pectin-Ag was substituted for the pectin in the multilayer systems, the properties of the formed coatings were significantly changed: the film rigidity and surface roughness increased, as well as the film growth acquired the parabolic character. All prepared multilayer films have shown antibacterial activity against gram-positive (Staphylococcus aureus) and gram-negative (Escherichia coli) bacteria. The significant decrease in the number of the adhered E. coli on the multilayer surface has been determined; moreover, many of the cells were misshapen with cytoplasm leaking. The prepared multilayer films showed a mild activity against S. aureus predominantly due to the antiadhesive effect. Our results indicate that antibacterial activity of biopolymer multilayers is determined by the film composition and physicochemical characteristics and can be associated with their antiadhesive and bactericidal behaviors.

In the present study, we report the development of poly (vinyl alcohol) (PVA) and chitosan oligosaccharide (COS)-based novel blend films. The concentration of COS was varied between 2.5–10.0 wt% within the films. The inclusion of COS added a brown hue to the films. FTIR spectroscopy revealed that the extent of intermolecular hydrogen bonding was most prominent in the film that contained 5.0 wt% of COS. The diffractograms showed that COS altered the degree of crystallinity of the films in a composition-dependent manner. As evident from the thermal analysis, COS content profoundly impacted the evaporation of water molecules from the composite films. Stress relaxation studies demonstrated that the blend films exhibited more mechanical stability as compared to the control film. The impedance profiles indicated the capacitive-dominant behavior of the prepared films. Ciprofloxacin HCl-loaded films showed excellent antimicrobial activity against Escherichia coli and Bacillus cereus. The prepared films were observed to be biocompatible. Hence, the prepared PVA/COS-based blend films may be explored for drug delivery applications.

The human intestinal contains rich and diverse microbiota that utilizes a variety of polysaccharides. The intestinal microflora extends the metabolic functions of the body, obtaining energy from indigestible dietary polysaccharides. It is not only a highly competitive environment but also a comprehensive collaboration for these polysaccharides, as the microbiota work to maximize the energy harvested from them through the intestine. Indigestible dietary polysaccharides help to manage colon health and host health by affecting the gut microbial population. These polysaccharides also influence the metabolic activity of the intestinal microbiota by stimulating the formation of SCFAs. Most of these metabolic activities affect host physiology because the epithelium absorbs secondary metabolites and end products or transports them to the liver, where they could exert other beneficial effects. This article reviews the carbohydrates existing in the human intestine, the regulating actions of indigestible polysaccharides on intestinal microflora, and the molecular basis of the degradation process of these polysaccharides. PRACTICAL APPLICATIONS: Large deals of researches have shown that indigestible polysaccharides possess an outstanding regulation effect on the intestinal microflora, which indicates that indigestible polysaccharides have the potential to be used as prebiotics in the functional food and pharmaceutical industries. However, it is not clear how gut microbiota metabolizes these dietary polysaccharides, and how the resulting gut metabolites may further affect the intestinal microflora population and metabolism. This paper reviews the indigestible dietary polysaccharides existing in the human intestine, the regulation of polysaccharides on gut microbiota, and the molecular basis of the degradation process of these polysaccharides. This review helps to better understand the relationship between indigestible dietary polysaccharides and intestinal microflora, which will provide powerful evidence for the potential use of these polysaccharides as functional foods.

The hydrogels based on nanocomposite pectin-Ag exhibiting the antibacterial activity (MIСAg = 0.02–0.81 mM) were obtained by ionotropic gelation. It was shown that the synthesized hydrogels had a high capacity for kanamycin (up to 70 wt. %). The obtained hydrogels provided a prolonged release of kanamycin in 0.9 % NaCl and enhanced its antibacterial activity (MIC decreased 10–20 times) due to the synergistic effect.

Layer-by-Layer assembled polyelectrolyte films offer the opportunity to control cell attachment and behavior on solid surfaces. In the present study, multilayer films based on negatively charged biopolymers (pectin, dextran sulfate, carboxymethylcellulose) and positively charged polysaccharide chitosan or synthetic polyelectrolyte polyethyleneimine has been prepared and evaluated. Physico-chemical properties of the formed multilayer films, including their growth, morphology, wettability, stability, and mechanical properties, have been studied. We demonstrated that chitosan-containing films are characterized by the linear growth, the defect-free surface, and predominantly viscoelastic properties. When chitosan is substituted for the polyethyleneimine in the multilayer system, the properties of the formed films are significantly altered: the rigidity and surface roughness increases, the film growth acquires the exponential character. The multilayer films were subsequently used for culturing mesenchymal stem cells. It has been determined that stem cells effectively adhered to chitosan-containing films and formed on them the monolayer culture of fibroblast-like cells with high viability. Our results show that cell attachment is a complex process which is not only governed by the surface functionality because one of the key parameter effects on cell adhesion is the stiffness of polyelectrolyte multilayer films. We therefore propose our Layer-by-Layer films for applications in tissue engineering. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A: 2093-2104, 2018.

Ultrathin LbL films based on protamine sulfate and pectins, including silver nanoparticles, have been obtained. Using the methods of quartz crystal microbalance and atomic force microscopy, the characteristics of the formed films are studied. It is shown that films based on pectin–Ag nanocomposites are elastic with a surface roughness of ≤3 nm, water content of

The depolymerization effect of UV/H

Formation of peritoneal adhesions is common complication after abdominal and pelvic surgery. They bear a significant health problem with an influence to quality of life and health care expenses. Promising approach for their prevention is using of biodegradable barrier films for physical separation of peritoneal surfaces. In the present study, highly porous pectin-based three-dimensional (3D) scaffolds were obtained by freeze-drying technique. Physico-chemical properties of the formed materials, including their morphology, porosity, density, and stability, have been studied. The evaluation of their biocompatibility, biodegradation, and potential antiadhesion effect was studied by in vivo experiment. To reinforce the scaffolds structure and improve their stability in physiological solutions, pectin chains were cross-linked with divalent cations. We determined optimal cross-linking conditions, which allow obtaining scaffolds with desired biodegradation rate. These cross-linked scaffolds fully dissolved within 8 days in the peritoneal cavity with low presence of complications and some antiadhesive effect. It has also been determined that mesenchymal stem cells from adipose tissue could effectively adhere to the scaffolds with preservation of their viability. Our results show that obtained materials can be suggested as mechanical scaffold for delivery of the stem cells culture to peritoneal surfaces as a part of complex antiadhesive barrier system.

Silver nanoparticles have been synthesized by reducing AgNO3 in an alkaline medium under the action of a natural polysaccharide, pectin. The influences of the type of pectin used and the reagent mixing order during the synthesis on the sizes and plasmon resonance properties of nanoparticles have been studied by optical spectroscopy and transmission electron microscopy. The conditions that make it possible to obtain silver hydrosols having predetermined particle sizes of 8 ± 2 to 22 ± 6 nm and stable to aggregation for at least 3 months have been determined.

The depolymerization effect of UV/H2O2 on the polysaccharides from Sargassum fusiforme (PSF), a brown algae, were studied. The structural changes of PSF before and after UV/H2O2 treatment were analyzed, and molecular weight changes during in vitro digestion were determined. Results indicated that the molecular weight of PSF was reduced from ∼289 to ∼12.6 kDa within 2 h with UV/150 mmol/L H2O2, and the depolymerization effect of UV/H2O2 was significantly higher than that of UV or H2O2 alone. In addition, the UV/H2O2 treatment had a high recovery rate of total sugar (93.54 %) and clearance rate of protein (76.34 %). The monosaccharide composition showed that UV/H2O2 treatment could increase the mole percentage of mannose (37.44 %) and decrease the mole percentage of fucose (14.88 %). The helix-coil transition, X-ray diffraction (XRD) and atomic force microscopy (AFM) imaging showed that the UV/H2O2 treatment depolymerized PSF. Rheological studies indicated that PSF with UV/H2O2 treatment had lower viscosity. In vitro digestion showed that PSF was minimally digested with the in vitro gastrointestinal tract simulation, but PSF with UV/H2O2 treatment could be digested in the low acid environment in the simulated gastric juice, but was minimally digested with the simulated intestinal juice. This studied suggested that the preparation and application of functional PSF with low molecular weight might be beneficial.

The development of environmentally friendly, non-toxic and cheap technology for synthesis of silver nanoparticles with desired properties is currently under intensive investigation because such materials show huge potential for numerous biomedical applications. In this paper, we propose the ‘green’ technique to obtain stable silver nanoparticles using reducing and stabilizing capacity of natural polysaccharide pectin. The relationship between physico-chemical characteristics of formed pectin-capped silver nanoparticles and type of used pectin, as well as synthesis conditions, has been determined. Pectin-Ag nanocomposites were produced via reduction of silver nitrate by pectin in alkaline medium at room temperature. The synthesized nanoparticles were characterized by ultraviolet-visible and Fourier-transform infrared spectroscopy, X-ray diffraction analysis, transmission electron microscopy and dynamic light scattering. It has been established that pectin-capped silver nanoparticles have a spherical shape with a mean diameter from 8 to 28 nm, a negative charge and an absorption maximum in the range from 401 to 412 nm, depending on the type of pectin constituent. Antibacterial activity of the free pectins and their nanocomposites with Ag0 was evaluated by diffusion and suspension methods against both gram-positive (Bacillus pumilus, Bacillus subtilis) and gram-negative (Escherichia coli) bacteria. The size and composition-dependent antibacterial activity of ‘green’ synthesized silver nanoparticles has been demonstrated. It has been shown that among the pectin varieties only amidated one displayed antibacterial action on Bacillus strains: the minimum inhibitory concentration (MIC) was 3.4–7.1 mg mL−1. It has been found that antibacterial activity of pectin-capped silver nanoparticles depended on the type of introduced pectin and its ratio. The synthesized nanoparticles exhibited significant antimicrobial activity toward gram-negative bacteria Escherichia coli (MIC 0.18-0.39 mM) as compared with gram-positive Bacillus bacteria (MIC 0.39–1.55 mM).