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Öğe An alginate-poly(acrylamide) hydrogel with TGF-beta 3 loaded nanoparticles for cartilage repair: Biodegradability, biocompatibility and protein adsorption(Elsevier, 2021) Saygili, Ecem; Kaya, Elif; Ilhan-Ayisigi, Esra; Saglam-Metiner, Pelin; Alarcin, Emine; Kazan, Aslihan; Akakin, DilekCurrent implantable materials are limited in terms of function as native tissue, and there is still no effective clinical treatment to restore articular impairments. Hereby, a functionalized polyacrylamide (PAAm)-alginate (Alg) Double Network (DN) hydrogel acting as an articular-like tissue is developed. These hydrogels sustain their mechanical stability under different temperature (+4 degrees C, 25 degrees C, 40 degrees C) and humidity conditions (60% and 75%) over 3 months. As for the functionalization, transforming growth factor beta-3 (TGF-beta 3) encapsulated (NPTGF-beta 3) and empty poly(lactide-co-glycolide) (PLGA) nanopartides (PLGA NPs) are synthesized by using microfluidic plat-form, wherein the mean particle sizes are determined as 81.94 +/- 92 nm and 126 +/- 4.52 nm with very low poly-dispersity indexes (PDI) of 0.194 and 0.137, respectively. Functionaliza lion process of PAAm-Alg hydrogels with ester-end PLGA NPs is confirmed by MR analysis, and higher viscoelastidty is obtained for functionalized hydrogels. Moreover, cartilage regeneration capability of these hydrogels is evaluated with in vitro and in vivo experiments. Compared with the PAAm-Alg hydrogels, functionalized formulations exhibit a better cell viability. Histological staining, and score distribution confirmed that proposed hydrogels significantly enhance regeneration of cartilage in rats due to stable hydrogel matrix and controlled release of TGF-beta 3. These findings demonstrated that PAAm-Alg hydrogels showed potential for cartilage repair and clinical application. (C) 2021 Elsevier B.V. All rights reserved.Öğe Antimicrobial activity of propolis and gentamycin against methicillin-resistant Staphylococcus aureus in a 3D thermo-sensitive hydrogel(Elsevier, 2019) Gezgin, Yuksel; Kazan, Aslihan; Ulucana, Fulden; Yesil-Celiktas, OzlemThe antibiotic resistance has become a major public health problem globally. Combinatorial administration of natural compounds and antibiotics is an alternative approach, particularly if synergistic effects can be elicited against multi-drug resistant bacteria. The aim of this study was to investigate the combinatorial activity of propolis and gentamycin against methicillin-resistant Staphylococcus aureus (MRSA) ATCC 43300 in three dimensional (3D) thermo-sensitive hydrogel (Poloxamer 407 25% (w/w)) to mimic the microenvironment realistically. Rheological properties, sol-gel transition temperature and the porosity of the hydrogel were determined. Subsequently, thermo-sensitive gel was loaded with propolis and gentamycin for evaluation of the combined effect. The fractional inhibitory concentration indices showed marked synergy and partial synergy without and within 3D termo-sensitive hydrogel at a range of 0.38 to 0.56, respectively. This 3D platform can be utilized to screen potential antimicrobial compounds and readily expanded to other microbial species.Öğe Cytotoxic and Nitric Oxide Inhibition Activities of Propolis Extract along with Microencapsulation by Complex Coacervation(Springer, 2016) Onbas, Rabia; Kazan, Aslihan; Nalbantsoy, Ayse; Yesil-Celiktas, OzlemIn this study, cytotoxicity of ethanol extract of propolis (EEP) originating from Sivas, Turkey was screened against several cancer cell lines, namely PC-3, U87MG, A-549, mPANC96, CaCo-2, MCF-7, HeLa, MDA-MB-231 and a non-tumor cell line HEK293 by MTT assay. The inhibition levels of inducible nitric oxide synthase (iNOS) were also determined by using RAW 264.7 macrophage cells following lipopolysaccharide (LPS) treatment. EEP exhibited significant cytotoxic nitric oxide inhibition activities with an IC50 value of 0.1 +/- 0.1 mu g/ml indicating a high potential as an anti-inflammatory agent. In spite of these promising results and the fact that propolis is a highly nutritive substance, its low solubility and bitter taste limit the applications as a natural supplement. Encapsulation might serve as a good strategy in order to overcome these problems. Complex coacervation was applied where the main focus was on surfactant type, polymer ratio (alginate: gelatin), stirring rate and concentration of core material. The mean particle size of unloaded microparticles were 22.62 mu m obtained with gelatin: alginate ratio of 1: 1 at a stirring rate of 1400 rpm with 2 ml of 1 % (w/v) sodium carboxymethyl cellulose (Na-CMC), whereas addition of EEP at a concentration of 100 mg/ml increased the mean particle size to 36.44 mu m and yielded an encapsulation efficiency of 98.77 %. The cytotoxicities of EEP loaded microparticles were also assessed both on MCF-7 and MDA-MB-231 where similar results were achieved as free EEP which can enhance the possible use of propolis extract in the industry as a natural supplement.Öğe Cytotoxic, antimicrobial and nitric oxide inhibitory activities of supercritical carbon dioxide extracted Prunus persica leaves(Springer, 2020) Koyu, Halil; Kazan, Aslihan; Nalbantsoy, Ayse; Yalcin, Husniye Tansel; Yesil-Celiktas, OzlemDifferent parts of Prunus persica as fruits, flowers, leaves and kernels have been consumed with dietary and therapeutic purposes traditionally. During fruit production, remarkable amount of leaves which can hold important bioactive groups as phenolics, have been left unutilized. the aim of this study was to investigate cytotoxic, antimicrobial and nitric oxide inhibitory activities of supercritical carbondioxide extracts of Prunus persica leaves. Among studied cell lines, supercritical carbon dioxide extract which was processed at 150 bar, 60 degrees C, and 6% co-solvent ethanol, exhibited remarkable cytotoxic activity against HeLa, MPanc-96 and MCF-7 cell lines with IC50 values of 12.22 mu g/ml, 28.17 mu g/ml and 35.51 mu g/ml respectively, whereas IC50 value of conventional solvent extract was above 50 mu g/ml. Minimum inhibitory concentration values determined for antibacterial and antifungal activities against Escherichia coli, Staphylococcus aureus, Staphylococcus epidermidis, Enterococcus faecalis, Enterococcus faecium and Candida albicans were found as 62.50 mu g/ml. Strong nitric oxide inhibition was achieved with IC50 of 9.30 mu g/ml. the promising results revealed that Prunus persica leaves may have remarkable potential as supplement both for drug and food industries. This study is the first report revealing cytotoxic, antimicrobial and nitric oxide inhibitory activity of supercritical carbon dioxide extract of Prunus persica leaves.Öğe An enzyme immobilized microreactor for continuous-flow biocatalysis of ginsenoside Rb1(Wiley, 2021) Kazan, Aslihan; Hu, Xihua; Stahl, Alina; Frerichs, Heike; Smirnova, Irina; Yesil-Celiktas, OzlemBACKGROUND Ginsenoside Rb1 is one of the major bioactive components of Panax ginseng C.A. Meyer (Araliaceae), a medicinal plant that has been used for therapeutic purposes for thousands of years in Asian countries. The pharmaceutical activity of ginsenoside Rb1 highly depends on molecular structure and its deglycosylated metabolites are known to be more potent bioactive compounds. However, these deglycosylated ginsenosides do not exist naturally so they are usually obtained by poorly selective methods, like chemical hydrolysis. RESULTS In this study, the development and characterization of an alginate-based immobilized enzyme microreactor for the catalytic conversion of ginsenoside Rb1 to more bioactive metabolites have been reported. Enzyme kinetic parameters were calculated and characterization tests (such as determination of surface area of alginate matrix, long-term use, and effect of residence time on conversion yield) were conducted. The system was operated under continuous-flow conditions and compared with acidic and batch enzymatic hydrolysis experiments, as conventional approaches. The enzymatic microreactor showed an enhanced activity by producing 13-fold higher amount of ginsenoside F2 than batch enzymatic hydrolysis. CONCLUSION Obtained results indicated that the newly developed enzymatic microreactor could successfully convert ginsenoside Rb1 to more active metabolites and have a potential for the biocatalysis of multiple ginsenosides, as well as pharmaceutically active compounds. (c) 2021 Society of Chemical Industry (SCI).Öğe Fabrication of Thymoquinone-Loaded Albumin Nanoparticles by Microfluidic Particle Synthesis and Their Effect on Planarian Regeneration(Wiley-V C H Verlag Gmbh, 2019) Kazan, Aslihan; Yesil-Celiktas, Ozlem; Zhang, Yu ShrikeThymoquinone is the main bioactive component of the plant Nigella sativa, which is commonly known as black seeds and has several therapeutic effects. However, clinical applications of thymoquinone are limited due to its hydrophobic nature. in this study, thymoquinone is encapsulated in albumin nanoparticles by using a microfluidic platform to overcome this limitation. the mean particle sizes of empty and thymoquinone-loaded nanoparticles are determined as 271.3 and 315.6 nm, respectively, with polydispersity index values both lower than 0.25. in addition to particle size distribution measurements, characterizations of the prepared nanoparticles such as zeta potential measurements, in vitro release studies, as well as scanning electron microscopy, Fourier-transform infrared, and differential scanning calorimetry analyses are also carried out. To determine the effect of thymoquinone on neural regeneration, planarians are used as the model organism. After application of free and encapsulated thymoquinone, planarians are amputated and the fragments are observed in terms of head and tail regeneration, swimming pattern, and behavior. the results indicate that thymoquinone affects their behavior and primarily enhances head regeneration of planarians. in addition, it is shown that encapsulation of thymoquinone not only enhances the thermal stability of the molecule but also decreases its toxicity.Öğe Formulation of organic and inorganic hydrogel matrices for immobilization of beta-glucosidase in microfluidic platform(Wiley, 2017) Kazan, Aslihan; Heymuth, Marcel; Karabulut, Dilan; Akay, Seref; Yildiz-Ozturk, Ece; Onbas, Rabia; Muderrisoglu, Cahit; Sargin, Sayit; Heils, Rene; Smirnova, Irina; Yesil-Celiktas, OzlemThe aim of this study was to formulate silica and alginate hydrogels for immobilization of beta-glucosidase. For this purpose, enzyme kinetics in hydrogels were determined, activity of immobilized enzymes was compared with that of free enzyme, and structures of silica and alginate hydrogels were characterized in terms of surface area and pore size. The addition of polyethylene oxide improved the mechanical strength of the silica gels and 68% of the initial activity of the enzyme was preserved after immobilizing into tetraethyl orthosilicate-polyethylene oxide matrix where the relative activity in alginate beads was 87%. The immobilized beta-glucosidase was loaded into glass-silicon-glass microreactors and catalysis of 4-nitrophenyl beta-D-glucopyranoside was carried out at various retention times (5, 10, and 15 min) to compare the performance of silica and alginate hydrogels as immobilization matrices. The results indicated that alginate hydrogels exhibited slightly better properties than silica, which can be utilized for biocatalysis in microfluidic platforms.Öğe A hepatocellular carcinoma-bone metastasis-on-a-chip model for studying thymoquinone-loaded anticancer nanoparticles(Springer Heidelberg, 2020) Sharifi, Fatemeh; Yesil-Celiktas, Ozlem; Kazan, Aslihan; Maharjan, Sushila; Saghazadeh, Saghi; Firoozbakhsh, Keikhosrow; Zhang, Yu ShrikeWe report the development of a metastasis-on-a-chip platform to model and track hepatocellular carcinoma (HCC)-bone metastasis and to analyze the inhibitory effect of an herb-based compound, thymoquinone (TQ), in hindering the migration of liver cancer cells into the bone compartment. the bioreactor consisted of two chambers, one accommodating encapsulated HepG2 cells and one bone-mimetic niche containing hydroxyapatite (HAp). Above these chambers, a microporous membrane was placed to resemble the vascular barrier, where medium was circulated over the membrane. It was observed that the liver cancer cells proliferated inside the tumor microtissue and disseminated from the HCC chamber to the circulatory flow and eventually entered the bone chamber. the number of metastatic HepG2 cells to the bone compartment was remarkably higher in the presence of HAp in the hydrogel. TQ was then used as a metastasis-controlling agent in both free form and encapsulated nanoparticles, to analyze its suppressing effect on HCC metastasis. Results indicated that the nanoparticle-encapsulated TQ provided a longer period of inhibitory effect. in summary, HCC-bone metastasis-on-a-chip platform was demonstrated to model certain key aspects of the cancer metastasis process, hence corroborating the potential of enabling investigations on metastasis-associated biology as well as improved anti-metastatic drug screening.Öğe A holistic engineering approach for utilization of olive pomace(Elsevier Science Bv, 2015) Akay, Fazilet; Kazan, Aslihan; Celiktas, Melih Soner; Yesil-Celiktas, OzlemOlive pomace is a by-product of olive oil production and an important biomass for the Mediterranean countries. The aim of this study was to optimize the oil extraction from olive pomace by supercritical CO2 and utilize the remaining biomass by hydrolysis. A Box-Behnken statistical design was used to evaluate the effect of temperature (30-80 degrees C), pressure (120-300 bar) and CO2 flow rate (10-20 g/min) for 60 min. The most effective variable was pressure (p < 0.005) and optimum extraction conditions were elicited as 68 degrees C, 280 bar and 20 g/min flow rate yielding 4.8% of oil. Additionally, the effect of particle size was investigated on extraction efficiency. Indeed, the oil yield was increased to 13.8% by decreasing the particle size from 2000 to 850-500 mu m. For utilization of remaining biomass, both supercritical CO2 (SC-CO2) and hexane de-oiled pomaces were subjected to acid and enzymatic hydrolyses. Hydrolyses with 2% of sulfuric acid for 90 min yielded 12.30 and 12.65 g/l reducing sugar from SC-CO2 and hexane treated biomasses, whereas the highest reducing sugar concentrations achieved with enzymatic hydrolysis with a substrate amount of 6g, 20-27% Cellic CTec2/Novozyme 188 for 24h were 12.72 g/l and 10.13 g/l, respectively. A holistic engineering approach is proposed where supercritical CO2 can be used as a main process to extract remaining oil in olive pomace and as a pretreatment loosen the structure in order to obtain liquor which can be converted to a biofuel. (C) 2015 Elsevier B.V. All rights reserved.Öğe A holistic engineering approach for utilization of olive pomace(Elsevier Science Bv, 2015) Akay, Fazilet; Kazan, Aslihan; Celiktas, Melih Soner; Yesil-Celiktas, OzlemOlive pomace is a by-product of olive oil production and an important biomass for the Mediterranean countries. The aim of this study was to optimize the oil extraction from olive pomace by supercritical CO2 and utilize the remaining biomass by hydrolysis. A Box-Behnken statistical design was used to evaluate the effect of temperature (30-80 degrees C), pressure (120-300 bar) and CO2 flow rate (10-20 g/min) for 60 min. The most effective variable was pressure (p < 0.005) and optimum extraction conditions were elicited as 68 degrees C, 280 bar and 20 g/min flow rate yielding 4.8% of oil. Additionally, the effect of particle size was investigated on extraction efficiency. Indeed, the oil yield was increased to 13.8% by decreasing the particle size from 2000 to 850-500 mu m. For utilization of remaining biomass, both supercritical CO2 (SC-CO2) and hexane de-oiled pomaces were subjected to acid and enzymatic hydrolyses. Hydrolyses with 2% of sulfuric acid for 90 min yielded 12.30 and 12.65 g/l reducing sugar from SC-CO2 and hexane treated biomasses, whereas the highest reducing sugar concentrations achieved with enzymatic hydrolysis with a substrate amount of 6g, 20-27% Cellic CTec2/Novozyme 188 for 24h were 12.72 g/l and 10.13 g/l, respectively. A holistic engineering approach is proposed where supercritical CO2 can be used as a main process to extract remaining oil in olive pomace and as a pretreatment loosen the structure in order to obtain liquor which can be converted to a biofuel. (C) 2015 Elsevier B.V. All rights reserved.Öğe A holistic engineering approach for utilization of olive pomace(Elsevier Science Bv, 2015) Akay, Fazilet; Kazan, Aslihan; Celiktas, Melih Soner; Yesil-Celiktas, OzlemOlive pomace is a by-product of olive oil production and an important biomass for the Mediterranean countries. The aim of this study was to optimize the oil extraction from olive pomace by supercritical CO2 and utilize the remaining biomass by hydrolysis. A Box-Behnken statistical design was used to evaluate the effect of temperature (30-80 degrees C), pressure (120-300 bar) and CO2 flow rate (10-20 g/min) for 60 min. The most effective variable was pressure (p < 0.005) and optimum extraction conditions were elicited as 68 degrees C, 280 bar and 20 g/min flow rate yielding 4.8% of oil. Additionally, the effect of particle size was investigated on extraction efficiency. Indeed, the oil yield was increased to 13.8% by decreasing the particle size from 2000 to 850-500 mu m. For utilization of remaining biomass, both supercritical CO2 (SC-CO2) and hexane de-oiled pomaces were subjected to acid and enzymatic hydrolyses. Hydrolyses with 2% of sulfuric acid for 90 min yielded 12.30 and 12.65 g/l reducing sugar from SC-CO2 and hexane treated biomasses, whereas the highest reducing sugar concentrations achieved with enzymatic hydrolysis with a substrate amount of 6g, 20-27% Cellic CTec2/Novozyme 188 for 24h were 12.72 g/l and 10.13 g/l, respectively. A holistic engineering approach is proposed where supercritical CO2 can be used as a main process to extract remaining oil in olive pomace and as a pretreatment loosen the structure in order to obtain liquor which can be converted to a biofuel. (C) 2015 Elsevier B.V. All rights reserved.Öğe In vitro tumor suppression properties of blueberry extracts in liquid and encapsulated forms(Springer, 2017) Kazan, Aslihan; Sevimli-Gur, Canan; Yesil-Celiktas, Ozlem; Dunford, Nurhan TugutBlueberries are rich in anthocyanins. Short shelf life of fresh blueberries and chemical instability of anthocyanins make the handling of blueberries very challenging. Hence, the objectives of this study are to characterize anthocyanin contents of blueberry water and acetone extracts and to encapsulate the extracts with chitosan. The encapsulated material was analyzed for its particle size distribution, thermal characteristics, and efficacy to reduce cancer cell proliferation. The solvent type had a significant effect on the yield and chemical composition of the blueberry extracts. The effect of the blueberry extracts on cancer cell lines was dose-dependent and varied with the cell type and the composition of the extract. The lowest IC50 values were achieved with the water extract obtained at 22 degrees C, 8.2, and 8.4 mu g/mL extract for human lung carcinoma (A549) and human breast adenocarcinoma (MCF7), respectively. The data reported in this study are essential for designing experiments to further examine the mechanism of the effect of the blueberry extracts on cancer cells.Öğe Investigating anthocyanin contents and in vitro tumor suppression properties of blueberry extracts prepared by various processes(Springer, 2016) Kazan, Aslihan; Sevimli-Gur, Canan; Yesil-Celiktas, Ozlem; Dunford, Nurhan TugutBlueberries are best known for their high content of flavonoids and other phenolic compounds which provide health benefits. The objective of this study was to investigate the effect of microwave, pressurized solvent, and supercritical carbon dioxide (SC-CO2) extraction techniques on the anthocyanin content of the water extracts obtained from dry whole blueberries. Effect of the blueberry extracts on selected cancer cell lines was also investigated. Neat and ethanol entrained SC-CO2 extracts did not contain detectable amount of anthocyanin. Microwave power did not have a significant effect on anthocyanin recovery. The blueberry juice (BJ) prepared by homogenization of fresh berries followed by microfiltration had the highest anthocyanin content among the extracts examined in this study. However, the blueberry water extracts prepared using other extraction techniques had a higher total phenolic content than the BJ. The effect of the blueberry extracts on the cancer cell lines was dose-dependent and varied with the cell type and the composition of the extract. BJ had a similar IC50 to the commercial cancer treatment drug doxorubicin for the cancer cell line MCF7. Further research is needed to elucidate the mechanism underlying the effect of blueberry extract composition on the viability of different cancer lines.Öğe Optimization of microwave assisted extraction of Morus nigra L. fruits maximizing tyrosinase inhibitory activity with isolation of bioactive constituents(Elsevier Sci Ltd, 2018) Koyu, Halil; Kazan, Aslihan; Demir, Serdar; Haznedaroglu, Mehmet Zeki; Yesil-Celiktas, OzlemMorus nigra L. is a beneficial food due to rich phenolic components. While aiming higher yields for bioactive constituents, reduction in terms of raw material, solvent, time and energy gained more importance to provide a sustainable life for human and nature. Microwave assisted extraction (MAE) of Morus nigra fruits was optimized in order to elicit process parameters maximizing bioactive metabolites and tyrosinase inhibitory activity. Spectrophotometry and UPLC-DAD-ESI-MS/MS systems were utilized for quantitative analysis of total phenol, flavonoid and anthocyanin contents. Optimum conditions for MAE were determined as 500 W, 35% ethanol, 10 min yielding 12.63 mg/g cya-3-glu equiv. anthocyanin and IC50 value of 1.60 mg/ml for tyrosinase inhibitory activity. Microwave extracts prevailed better outcomes compared to conventional extraction methods (10.93 mg/g content with IC50 of 2.81 mg/ml). MAE could be considered as an advanced technique to obtain extracts from Morus nigra fruits with higher bioactive content and activity.Öğe Optimizing subcritical water extraction of Morus nigra L. fruits for maximization of tyrosinase inhibitory activity(Elsevier Science Bv, 2017) Koyu, Halil; Kazan, Aslihan; Ozturk, Taylan Kurtulus; Yesil-Celiktas, Ozlem; Haznedaroglu, Mehmet ZekiThe process of preparing extracts for pharmaceutical industry from natural resources is a challenge to obtain effective constituents besides using resources efficiently considering public health and environment. Advanced extraction technologies aim to provide high efficiency and selectivity apart from decreasing the demand for organic solvents causing toxic residuals. In line with this objective, optimization of subcritical water extraction of Morus nigra L. fruits had been carried out with response surface methodology. Bioactive constituents as phenolics, flavonoids and anthocyanins were determined with spectrophotometry and LC MS/MS analysis. Optimum extraction conditions were elicited as 60 degrees C, 60 min, 2 ml/min yielding an IC50 value of 1.84 mg/ml and subcritical conditions at 120 degrees C, 60 min, 2ml/min yielding 1.71 mg/ml which possess stronger activity than extracts of conventional solvent extraction (2.81 mg/ml) regarding tyrosinase inhibitory activity. Consequently, subcritical water could be a pioneer for green extraction systems for Moms nigra L. fruits compared to conventional solvent extraction. (C) 2017 Published by Elsevier B.V.Öğe Processing of protease under sub- and supercritical conditions for activity and stability enhancement(Elsevier Science Bv, 2014) Senyay-Oncel, Deniz; Kazan, Aslihan; Yesil-Celiktas, OzlemEnzymatic reactions with supercritical carbon dioxide (SC-CO2) have received increased attention during the last decade. The objective of this study was to alter the activity and stability of Bacillus sp. protease under SC-CO2 conditions. The activity and stability of protease were evaluated according to the effects of operational variables, temperature (28-80 degrees C), pressure (60-300 bar), CO2 flow (2-10 g/min) and process duration (60-180 min). Best conditions were identified as 300 bar, 54 degrees C, 6 g/min CO2 flow and 120 min of process time efficient 54.4% (417.50 mu mol/ml/min) as against to the untreated enzyme. Activity enhancement was observed with the raise of pressure while low flow rates decreased the activity by 5.1% with a flow rate of 2 g/min under supercritical conditions. Potential mechanisms for pressure stimulated activation and stabilization were investigated by NMR, SEM, FTIR, SOS-PAGE and XPS analyses. As a result, applications of SC-CO2 medium for enzymatic processes are expected to become sustainable and important with economical synthetic and environmentally friendly protocols. (C) 2014 Elsevier B.V. All rights reserved.Öğe Supercritical fluid extraction of Prunus persica leaves and utilization possibilities as a source of phenolic compounds(Elsevier Science Bv, 2014) Kazan, Aslihan; Koyu, Halil; Turu, Irem Cemre; Yesil-Celiktas, OzlemMediterranean countries contribute highly on world peach production and tonnes of waste leaves are released due to pruning. The aim of this study was to investigate the utilization possibilities of the leaves by supercritical fluid extraction. A statistical design was used to evaluate the effect of temperature (40-80 degrees C), pressure (150-300 bar) and concentration of ethanol as co-solvent (6-20%) at a flow rate of 15 g/min and for a duration of 60 min. The most effective variables were found as pressure and co-solvent ratio (p < 0.005). Optimum extraction conditions were elicited as 60 degrees C, 150 bar and 6% co-solvent yielding a total phenol content of 79.92 mg GAE/g extract, EC50 value of 232.20 mu g/ml and a radical scavenging activity of 53.25% which was higher than the value obtained by conventional solvent extraction method (32.23%). Consequently, Prunus persica L. leaves were found as a potential phenolic source for industrial applications. (C) 2014 Elsevier B.V. All rights reserved.Öğe Synthesis and characterization of cryogel structures for isolation of EPSs from Botryococcus braunii(Elsevier Sci Ltd, 2016) Turu, Irem Cemre; Turkcan-Kayhan, Ceren; Kazan, Aslihan; Yildiz-Ozturk, Ece; Akgol, Sinan; Yesil-Celiktas, OzlemIn this study, the objective was to separate exopolysaccharides (EPSs) released in the broth subsequent to outdoor cultivation of Botryococcus braunii. For this, poly(2-hydroxyethyl methacrylate) (PHEMA) cryogels were synthesized. After that, the surface was modified by coupling Concanavalin A. Box-Behnken statistical design was used to evaluate the effect of freezing temperature, Con A concentration and flow rate on Con A binding capacity. Optimum synthesis conditions were elicited as -14.48 degrees C freezing temperature, 1.00 mg/ml Con A concentration and 0.30 ml/min flow rate yielding 3.18 mg Con A/g cryogel, whereas -16 degrees C, 1.00 mg/ml and 0.30 ml/min yielded the highest (3.38 mg) binding capacity in experimental cryogel preparation. The EPS adsorption capacity of the optimum cryogel column was found as 3.26 mg EPS/g cryogel corresponding to adsorption yield of 80%. Besides; swelling test, elemental analysis, Micro-CT, SEM and FTIR analysis were carried out for characterization of the synthesized cryogels. (C) 2016 Elsevier Ltd. All rights reserved.
