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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...

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.

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.

The gut microbiota appears critical in the metabolic health and anti‐disease activity. In this review, we discuss three brown seaweed polysaccharides (alginate, laminarin, fucoidan) for their structural information, the digestive behaviour and the effects on gut microbiota. Bioactivities are associated with various physicochemical properties, like solubility, viscosity, hydration properties, molecular weight, monosaccharide composition, and so on. Brown seaweed polysaccharides can be completely utilised by microbes in the large bowel, and they can regulate the gut microbiota. The ultimate metabolite of these polysaccharides is mainly short‐chain fatty acids, which are able to regulate the ecology of the gut microbiota by increasing the growth of beneficial bacteria and inhibiting the growth of some harmful bacteria. In addition, this article also discusses the relationship between the structure and activity of modulating the gut microbiota. Results show that polysaccharides with low molecular weight are more conductive to modulate gut microbiota.

Conditions for the preparation of stable to sedimentation aqueous dispersions of interpolyelectrolyte complexes based on chitosan (Chit) and pectin (Pect) with particle diameter 0.5-0.9 μm for Pect/Chit and 1.0-2.0 μm for Chit/Pect have been determined. The absolute value of the zeta potential of these complexes is >10 mV for Pect/Chit and Chit/Pect when the molar ratio of the ionogenic groups of the polymers $$ {n}_{\mathrm{COOH}}/{n}_{{\mathrm{NH}}_2} $$ is 0.4-4.6 for Pect/Chit and 0.02-0.63 for Chit/Pect. Optical spectroscopy and electrophoretic light scattering have been used to determine the effect of molecular mass and the content of the free ionogenic groups in the polysaccharide macromolecules as well as the order of mixing the solution on the formation and properties of these interpolyelectrolyte complexes.

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.

There are few studies on seaweed polysaccharides with UV/H

The study aimed to study the effects on structural characteristics and anti-inflammatory activities of algal sulfated polysaccharides isolated from Gracilaria lemaneiformis (GLP) after a combined treatment of UV irradiation (average irradiance of 6500 mJ/cm

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.

In the present study, ultrathin poly(L-lactic acid) (PLLA) films were fabricated using the spin-coating technique. Physicochemical properties of the formed materials, including their morphology, thickness, transparency, and contact angle, have been studied. We determined that the morphology of PLLA films could be regulated by changing the polymer concentration and humidity. By altering the humidity, microporous and flat PLLA films can be fabricated. The obtained samples were subsequently used for culturing mesenchymal stem cells and fibroblasts. It has been determined that cells effectively adhered to prepared films and formed on them a monolayer culture with high viability. It has been shown that PLLA films are suitable for the entrapment of curcumin (up to 12.1 μm cm−2) and provide its sustained release in solutions isotonic to blood plasma. The obtained PLLA films appear to be prospective materials for potential application in regenerative medicine as part of cell-containing tissue engineered dressings for chronic wound treatment.

The study explored the changes of a sulfated polysaccharide (SP) from Gracilaria Lemaneiformis during simulated human digestive system. The results showed SP was scarcely degraded without significant difference. Moreover, the results of fermentation in vitro indicated 53.7% of SP were utilized by gut microbiota with the molecular weight decreasing by 59.41% at 48 h. Meanwhile, 50.07 ± 2.82 mM of short chain fatty acids were produced in culture medium. Besides, in contrast with the regulation of galacto-oligosaccharide sacrificing diversity and richness of community, SP could regulate the composition of microbiota in a mild way. What’s more, Proteobacteria and Firmicutes were the most sensitive phyla responding to changes of pH values in this study. And Sutterella, Phascolarctobacterium, Parabacteroides, Lachnospiraceae_UCG-004, Desulfovibrio and Bacteroides were dominant genera for degrading and utilizing SP. Furthermore, the metagenomic function characteristics of microbes might be changed by SP. Thus, SP could be a potential prebiotic.

Solid (smooth) and porous films of polydimethylsiloxane (PDMS) have been obtained; the effect of their structure on the adhesion of mesenchymal stem cells (MSCs) on their surface was found. It is shown that modification of these films with a (chitosan/pectin)4 multilayer increased the efficiency of viable cell adhesion. A (3-aminopropyl)triethoxysilane–glutaraldehyde system was used to enhance the binding of the polysaccharide layer to the hydrophobic surface of PDMS. It was found that MSCs formed a monolayer culture of the fibroblast-like cells with high viability on porous PDMS modified with (chitosan/pectin)4.

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.

(Polyethyleneimine/bovine serum albumin) n ((PEI/BSA)n) multilayer films (n = 1–10) are produced via the layer-by-later deposition of polyelectrolytes. It is shown that thickness and morphology of the formed coatings can be controlled by varying the solution’s ionic strength during alternating adsorption of the components. (PEI/BSA)10 multilayer systems that contain up to 0.6 mg of antiseptic miramistin per 1 cm2 of film were created. It is established that the kinetics of miramistin release from (PEI/BSA)10 films in phosphate buffers and physiological solutions obey the Korsmeyer–Peppas equation with a high degree of accuracy (R2 > 0.95).

There are few studies on seaweed polysaccharides with UV/H2O2 treatment, so the aim of this study was to evaluate the effects of UV/H2O2 treatment on physicochemical properties and RAW 264.7 cells responses of polysaccharides from Sargassum fusiforme (PSF). Results showed that the contents of reducing sugar and sulfate in PSF with UV/H2O2 treatment for 2 h increased by 202.86% and 31.77%, respectively, and the contents of total sugar, protein and uronic acid decreased by 14.29%, 57.11% and 43.18% compared with those of original polysaccharides. In addition, UV/H2O2 treatment did not change the monosaccharide types of original polysaccharides, but it could change its monosaccharide composition and surface morphology. Besides, polysaccharides after UV/H2O2 treatment for 0.5–2 h had lower toxicity than original polysaccharides in RAW 264.7 cells. Typically, PSF with UV/H2O2 treatment for 2 h (PSF-T2) could effectively inhibit pro-inflammatory molecules production (including NO, IL-1β, IL-6 and TNF-α), and down-regulate related genes expression (including Tlr4, Irak, Il-1β, Il-6, Il-12 and Tnf-α). Therefore, UV/H2O2 treatment is a potential way to prepare polysaccharide with better anti-inflammatory activity.

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.

The study aimed to study the effects on structural characteristics and anti-inflammatory activities of algal sulfated polysaccharides isolated from Gracilaria lemaneiformis (GLP) after a combined treatment of UV irradiation (average irradiance of 6500 mJ/cm2) and H2O2 (50 mmol/L) for various time periods up to 60 min. After a 30-min treatment, the molecular weight and particle size of GLP was decreased by 15 and 2.6 fold, respectively with small but significant decrease in the contents of total sugars, uronic acids and proteins. There seemed to have no starch and the presence of longer side chains of branches in the GLP samples before and after UV/H2O2 treatment based on the I2-KI assay. Scanning electron microscope and atomic force microscope analysis confirmed that the UV/H2O2 treatment could modify the surface morphology of GLP. GLP treated for 5 min possessed the strongest in vitro anti-inflammatory activity by inhibiting the production of nitric oxide, tumor necrosis factor-α and interleukin-6 by 60.49%, 62.81% and 36.29%, respectively in IEC-6 cells when compared to the model. Therefore, UV/H2O2 treatment had the potential to enhance the anti-inflammatory activity of algal sulfated polysaccharides.

This study explored the preventive effects of polysaccharide extracted from Gracilaria Lemaneiformis in mice with colitis induced by dextran sulfate sodium (DSS). FT-IR spectrum showed that SP was a typical sulfated polysaccharide (SP), which contained high content of S element in energy dispersive spectrometer (EDS) analysis. SP was mainly composed of (1 → 3)-linked glycosidic bonds. Our results showed that SP could improve physical conditions of mice via alleviating weight loss and appetite suppression. Besides, SP could decrease the content of endotoxin (ET), lipopolysaccharide binding protein (LBP) and the activity of myeloperoxidase in serum. Meanwhile, SP also suppressed the secretion of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) and interleukin-1β (IL-1β) in colon tissue. These indicators showed that SP had ameliorated colitis symptoms. Furthermore, histological analysis indicated that SP could maintain healthy colonic microstructure including crypt, goblet cell and mucosal muscularis. Meanwhile, immunohistochemical results showed that tight junction proteins, including Claudin-1, ZO-1, and mucin (MUC-2) were promoted in colon with SP treatment. In conclusion, SP could enhance intestinal barrier, protect colonic microstructure and attenuate DSS-induced colonic injuries in mice, which suggested that SP could be a potentially functional component against colitis.

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).

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.