Browsing by Subject "polysaccharide"
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Item Levan production by Zymomonas mobilis in batch and continuous fermentation systems(2014) Silbir S.; Dagbagli S.; Yegin S.; Baysal T.; Goksungur Y.Levan production in batch and continuous fermentation systems by Zymomonas mobilis B-14023 was investigated. The culture medium used in both of the fermentation systems contained sucrose and various organic nitrogen sources. Maximum concentration of levan was produced with yeast extract among the nitrogen sources tested. Response surface methodology was used to investigate the effects of three factors on the concentration of levan in batch cultures of Z. mobilis. Maximum levan concentration was 40.2 g/L and this concentration was reached at the optimum levels of process variables, which were 299.1 g/L initial substrate concentration, 42.3 h incubation time, and initial pH 6.0. Continuous fermentation experiments were done in packed bed bioreactor using Ca-alginate immobilized Z. mobilis cells. The highest levan concentration (31.8 ± 0.21 g/L) was obtained at a dilution rate of 0.14 h-1 while maximum volumetric productivity (6.556 g/(L h)) was obtained at a dilution rate of 0.22 h-1. Increasing the dilution rate resulted in decreased levan and increased residual sugar concentrations. © 2013 Elsevier Ltd. All rights reserved.Item Mucosal trauma induced apoptosis in guinea pig middle ear: Comparision of hemostatic agents(Elsevier Ireland Ltd, 2014) Eren E.; Başoğlu M.S.; Kulduk E.; Şimsek F.; Inan S.Objective: The aim of this study is to compare the effects of the absorbable gelatin sponge (AGS), microporous polysaccharide hemospheres (MPH), and Ankaferd on wound healing after middle ear trauma and to evaluate their ototoxicity in an experimental guinea pig model. Methods: Middle ear mucosal trauma was created in 21 healthy adult guinea pigs. MPH, Ankaferd, and AGS were applied into the right tympanic bulla of the guinea pigs (7 ears for each treatment modality). The left ears of the seven animals were used as the sham group. At the fourth postoperative week (28-30 days), the guinea pigs were decapitated. Apoptosis was investigated, and the expression of Bcl-xl, Apaf, p53, cytochrome 3, and caspase 3 were evaluated. Results: The Ankaferd and AGS groups demonstrated significantly lower epithelial thickness, inflammation, and capillary dilatation than did the control group ( p<. 0.001, <0.001, /0.001, <0.001/, 0.005, and 0.005, respectively). A statistically significant decrease in Bcl-xl staining was observed in the middle ears of animals treated with MPH ( p= 0.003). There was significantly higher caspase 3 expression in the Ankaferd and AGS groups than in the control group ( p<. 0.001 and p= 0.002, respectively). Conclusion: Light microscopy indicates that Ankaferd and AGS create less inflammation and increased caspase expression, which seems to induce inflammatory cell apoptosis. Ankaferd seems to be a promising hemostatic agent in otology. © 2014 Elsevier Ireland Ltd.Item Quantitative approach to lectin-based glycoprofiling of thymic tissues in the control- and the dexamethasone-treated mice(Churchill Livingstone, 2016) Balcan E.Dexamethasone (DEX) is the most commonly used synthetic glucocorticoid in treatment of various inflammatory conditions. Here we focused on evaluating the effect of DEX on apoptosis and glycan profile in the mouse thymic tissues. Histological examinations revealed that the DEX treatment cause severe alterations in thymus, such as disruption of thymic capsule, impaired epithelial cell-thymocyte contacts, cellular loss and increased apoptosis. The identification of thymic glycans in the control- and the DEX-treated mice was carried out by using a panel of five plant lectins, Maackia amurensis agglutinin (MAA), peanut agglutinin (PNA), Sambucus nigra agglutinin (SNA), Concanavalin A (ConA) and wheat germ agglutinin (WGA). Lectin histochemistry results showed that glycosylation pattern of thymus changes upon DEX treatment. For further detailed quantitative analyses of the binding intensities for each lectin, histochemical data were scored as high positive (HP), mild positive (MP) and low positive (LP) and differences among signaling densities were investigated. The staining patterns of thymic regions observed with lectin histochemistry suggest that DEX can affect the thymic glycan profile as well as thymocyte apoptosis. These results are consistent with the opinion that not only sialic acid, but also other sugar motifs may be responsible for thymocyte development. © 2016 Elsevier Ltd.Item Ultrasound assisted extraction of polysaccharides from hazelnut skin(SAGE Publications Inc., 2016) Yilmaz T.; Tavman Ş.In this study ultrasound assisted extraction (UAE) of polysaccharides from hazelnut skin has been studied. Optimum sonication time has been evaluated depending on responses such as amount of carbohydrate and dried sample and thermogravimetric analysis. Chemical and structural properties of extracted material have been determined by Fourier transform spectroscopy attenuated-total reflectance (FTIR-ATR) spectroscopy. Pretreated hazelnut skin powders were extracted in distilled water. Mixture was sonicated by ultrasonic processor probe for 15, 30, 45, 60, 90, and 120 min. The results of UAE showed that maximum ethanol insoluble extracts in 60 min and the highest dry matter content could be obtained in 120 min extraction. Although total carbohydrate content of ethanol insoluble dry extract decreased with time, total carbohydrate in ethanol soluble fraction increased. Polysaccharides extracted from hazelnut skin were assumed to be pectic polysaccharide according to the literature survey of FTIR analysis result. Application time of UAE has an important effect on extraction of polysaccharide from hazelnut skin. This affect could be summarized by enhancing extraction yield up to critical level. Decrease of the yield in ethanol insoluble part could be explained by polymer decomposition. Most suitable model was hyperbolic model by having the lowest root mean square error and the highest R2 values. © SAGE Publications.Item Removal of erythrosine dye from aqueous solutions using magnetic chitosan with erythrosine as imprinted molecules(Taylor and Francis Inc., 2016) Eser A.; Aydemir T.; Becerik S.; Dinçer A.A novel, chitosan coating on the surface of magnetite (Fe3O4) (erythrosine-imprinted magnetic chitosan (EIMC)) was successfully synthesized using erythrosine (ER) as a template for adsorption and the removal of ER from aqueous solutions. Characterization of the obtained EIMC was achieved by FTIR spectra, SEM micrographs, and TGA analysis. Batch adsorption experiments of EIMC and non-imprinted magnetic chitosan (NIMC) were performed to investigate the adsorption conditions. The results showed that the maximum adsorption capacity for EIMC and NIMC was observed at pH 6 and temperature 40°C. Equilibrium adsorption was achieved within 3 h. Adsorption process could be well described by Freundlich adsorption isotherms. Thermodynamic parameters namely ΔG°, ΔH°, and ΔS° of the ER adsorption process were calculated. The negative values of Gibbs free energy of adsorption (ΔG°) indicated the spontaneity of the adsorption of ER dye on the EIMC and NIMC. Desorption of ER from EIMC and NIMC could be done rapidly using 0.1 M NaOH solution and the beads could be used again to remove ER. Results show that imprinting technique increases the removal amount of ER dye from aqueous solutions. © 2015 Balaban Desalination Publications. All rights reserved.Item Modelling and Optimization of Uranium (VI) Ions Adsorption Onto Nano-ZnO/Chitosan Bio-composite Beads with Response Surface Methodology (RSM)(Springer New York LLC, 2018) Kaynar Ü.H.; Çınar S.; Çam Kaynar S.; Ayvacıklı M.; Aydemir T.Nano-ZnO-chitosan bio-composite beads were prepared for the sorption of UO22+ from aqueous media. The resulting nano-ZnO/CTS bio-composite beads were characterized by TEM, XRD etc. The sorption of UO22+ by bio-composite beads was optimized using RSM. The correlation between four variables was modelled and studied. According to RSM data, correlation coefficients (R2 = 0.99) and probability F-values (F = 2.24 × 10− 10) show that the model fits the experimental data well. Adsorption capacity for nano-ZnO/CTS bio-composite beads was obtained at 148.7 mg/g under optimum conditions. The results indicate that nano-ZnO/CTS bio-composite beads are appropriate for the adsorption of UO22+ ions from aqueous media. Also, the suitability of adsorption values to adsorption isotherms was researched and thermodynamic data were calculated. © 2017, Springer Science+Business Media, LLC.Item Drug Delivery Systems for Cancer Treatment: A Review of Marine-derived Polysaccharides(Bentham Science Publishers, 2022) Atmaca H.; Oguz F.; Ilhan S.Cancer is a disease characterized by uncontrolled cell proliferation and the spread of cells to other tissues and remains one of the worldwide problems waiting to be solved. There are various treatment strategies for cancer, such as chemotherapy, surgery, radiotherapy, and immunotherapy, although it varies according to its type and stage. Many chemotherapeutic agents have limited clinical use due to lack of efficacy, off-target toxicity, metabolic instability, or poor pharmacokinetics. One possible solution to this high rate of clinical failure is to design drug delivery systems that deliver drugs in a controlled and specific manner and are not toxic to normal cells. Marine systems contain biodiversity, including components and materials that can be used in biomedical applications and therapy. Biomaterials such as chitin, chitosan, alginate, carrageenan, fucoidan, hyaluronan, agarose, and ulvan obtained from marine organisms have found use in DDSs today. These polysaccharides are biocompatible, non-toxic, biodegradable, and cost-effective, making them ideal raw materials for increasingly complex DDSs with a potentially regulated release. In this review, the contributions of polysaccharides from the marine environment to the development of anticancer drugs in DDSs will be discussed. © 2022 Bentham Science Publishers.Item Methyl cellulose/okra mucilage composite films, functionalized with Hypericum perforatum oil and gentamicin, as a potential wound dressing(Elsevier B.V., 2024) Coban S.N.; Polatoglu I.; Eroglu E.There is a growing demand for the development of functional wound dressings enriched with bioactive natural compounds to improve the quality of life of the population by accelerating the healing process of chronic wounds. In this regard, a functional composite film of okra mucilage (OM) and methylcellulose (MC) incorporated with Hypericum perforatum oil (Hp) and gentamicin (G) was prepared and characterized as a wound dressing. Increasing Hp resulted in improved film properties with a more porous structure, higher WVTR, and lower surface hydrophobicity. Furthermore, incorporating Hp into OM:MC films led to increased elongation at the break while reducing the tensile strength of the films. The highest values of total antioxidant capacity (1.09–1.16 mM trolox equivalent) and total phenolic content (13.76–16.94 μg GA equivalent mL−1) were measured in the composite films containing the highest Hp concentration (1.5 %). In addition, OM:MC/HpG composite films exhibited significant antibacterial activity against both E. coli and S. aureus and prevented the transmission of these bacteria through the films. Hp incorporation reduced the cytotoxic effects of OM:MC films on BJ cells and increased the wound closure rate in vitro. In conclusion, the developed OM:MC/HpG composite film can be a promising candidate as a novel wound dressing with its superior properties. © 2023