Enhanced In Vitro Anti-Photoaging Effect of Degraded Seaweed Polysaccharides by UV/H2O2 Treatment.

The high molecular weight and poor solubility of seaweed polysaccharides have limited their function and application. In this study, ultraviolet/hydrogen peroxide (UV/H2O2) treatment was used to prepare low-molecular-weight seaweed polysaccharides from Sargassum fusiforme. The effects of UV/H2O2 treatment on the physicochemical properties and anti-photoaging activity of S. fusiforme polysaccharides were studied. UV/H2O2 treatment effectively degraded polysaccharides from S. fusiforme (DSFPs), reducing their molecular weight from 271 kDa to 26 kDa after 2 h treatment. The treatment did not affect the functional groups in DSFPs but changed their molar percentage of monosaccharide composition and morphology. The effects of the treatment on the anti-photoaging function of S. fusiforme polysaccharides were investigated using human epidermal HaCaT cells in vitro. DFSPs significantly improved the cell viability and hydroxyproline secretion of UVB-irradiated HaCaT cells. In particular, DSFP-45 obtained from UV/H2O2 treatment for 45 min showed the best anti-photoaging effect. Moreover, DSFP-45 significantly increased the content and expression of collagen I and decreased those of pro-inflammatory cytokines, including interleukin-1ß, interleukin-6, and tumor necrosis factor-α. Thus, UV/H2O2 treatment could effectively improve the anti-photoaging activity of S. fusiforme polysaccharides. These results provide some insights for developing novel and efficient anti-photoaging drugs or functional foods from seaweed polysaccharides.

Alginate coated biogenic silver nanoparticles for the treatment of Pseudomonas infections in rainbow trout.

Pseudomonas species are among the main pathogens causing rainbow trout infections. The present study provides a simple, green, sustainable, and rapid technique to synthesize of biogenic alginate-capped silver nanoparticles (Alg-Ag NPs) suitable for the treatment of Pseudomonas infections. It has been shown that the mechanism (aggregative or autocatalytic) of Alg-Ag NPs formation depended on Alg concentration and the heating approach used. The rate constants and activation energy were calculated. Alg-Ag NPs were characterized by UV-Vis, FTIR, XRD, TEM, AFM, XPS, and DLS. The optimal conditions for the fabrication of spherically-shaped (17-19 nm) and negatively-charged (zeta-potential <-50 mV) Alg-Ag NPs, which are stable during 9 months, included hot-plate assisted synthesis at 100 °C in diluted (1 mg/mL) Alg solutions. In vitro studies showed that Alg-Ag NPs exhibited prominent antimicrobial activity against collection Pseudomonas strains (inhibition zones ranged from 9.0 ± 1.0 to 19.0 ± 1.0 mm), with no significant loss of antibacterial efficacy after 9 months of storage. AFM analysis confirmed that the antibacterial effect of Alg-Ag NPs dealt with the direct nanomechanical disrupting of bacterial cells. The ability of Alg-Ag NPs to inhibit the growth of virulent P.aeruginosa, P.fluorescens and P. putida strains isolated from infected rainbow trout was evaluated. All tested strains were susceptible to Alg(10)-Ag NPs, while Alg(1)-Ag NPs demonstrated a limited strain-specific antibacterial effect. The obtained data displayed the prospects for the application of biogenic Alg-Ag NPs to create novel delivery systems for combating Pseudomonas infections in rainbow trout.

Honeycomb-Structured Porous Films from Poly(3-hydroxybutyrate) and Poly(3-hydroxybutyrate-co-3-hydroxyvalerate): Physicochemical Characterization and Mesenchymal Stem Cells Behavior.

Surface morphology affects cell attachment and proliferation. In this research, different films made of biodegradable polymers, poly(3-hydroxybutyrate) (PHB) and poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHB-co-HV), containing different molecular weights, with microstructured surfaces were investigated. Two methods were used to obtain patterned films-water-assisted self-assembly ("breath figure") and spin-coating techniques. The water-assisted technique made it possible to obtain porous films with a self-assembled pore structure, which is dependent on the monomer composition of a polymer along with its molecular weight and the technique parameters (distance from the nozzle, volume, and polymer concentration in working solution). Their pore morphologies were evaluated and their hydrophobicity was examined. Mesenchymal stem cells (MSCs) isolated from bone marrow were cultivated on a porous film surface. MSCs' attachment differed markedly depending on surface morphology. On strip-formed stamp films, MSCs elongated along the structure, however, they interacted with a larger area of film surface. The honeycomb films and column type films did not set the direction of extrusion, but cell flattening depended on structure topography. Thus, stem cells can "feel" the various surface morphologies of self-assembled honeycomb films and change their behavior depending on it.

Physicochemical aspects of design of ultrathin films based on chitosan, pectin, and their silver nanocomposites with antiadhesive and bactericidal potential.

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.

Fabrication and Characterization of Poly (vinyl alcohol) and Chitosan Oligosaccharide-Based Blend Films.

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.

Influence of UV/H2O2 treatment on polysaccharides from Sargassum fusiforme: Physicochemical properties and RAW 264.7 cells responses.

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-1ß, IL-6 and TNF-α), and down-regulate related genes expression (including Tlr4, Irak, Il-1ß, Il-6, Il-12 and Tnf-α). Therefore, UV/H2O2 treatment is a potential way to prepare polysaccharide with better anti-inflammatory activity.

Structural characteristics and anti-inflammatory activity of UV/H2O2-treated algal sulfated polysaccharide from Gracilaria lemaneiformis.

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.

Polyvinyl alcohol and pectin blended films: Preparation, characterization, and mesenchymal stem cells attachment.

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.

Structural characteristic of a sulfated polysaccharide from Gracilaria Lemaneiformis and its lipid metabolism regulation effect.

A sulfated polysaccharide extracted from Gracilaria lemaneiformis (GLP) with a prominent effect in regulating lipid metabolism was isolated. The molecular weight was 31.5 kDa and it was composed mainly of galactose, glucose and xylose. Fourier-transform infrared (FT-IR) spectrum and nuclear magnetic resonance (NMR) analysis suggested that GLP was composed of the following repeating unit: [3-ß-Gal-4(OSO3)-1→4-α-3,6-anhydrogal-2(OSO3)-1→]. GLP could significantly decrease serum total cholesterol, triglyceride and free fatty acid levels and lower alanine aminotransferase and aspartate aminotransferase activities in high-fat-diet mice. Additionally, GLP could keep the body weight and attenuate accumulation of fat surrounding the liver and epididymis induced by high-fat diet. Results of RT-PCR indicated that GLP might regulate lipid metabolism and accelerate free fatty acid oxidation by up-regulating the expression of the PPARα, ACS and CPT1a gene. The present study suggests that GLP may be potentially useful for regulating lipid metabolism.

Fabrication and characterization of ultrathin spin-coated poly(L-lactic acid) films suitable for cell attachment and curcumin loading.

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.

Degradation of polysaccharides from Sargassum fusiforme using UV/H2O2 and its effects on structural characteristics.

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.

Fabrication and characterization of pectin-based three-dimensional porous scaffolds suitable for treatment of peritoneal adhesions.

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.

Layer-by-layer buildup of polysaccharide-containing films: Physico-chemical properties and mesenchymal stem cells adhesion.

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.