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    Bio-active nanoemulsions enriched with gold nanoparticle, marigold extracts and lipoic acid: In vitro investigations
    (Elsevier Science Bv, 2014) Guler, Emine; Barlas, F. Baris; Yavuz, Murat; Demir, Bilal; Gumus, Z. Pinar; Baspinar, Yucel; Coskunol, Hakan
    A novel and efficient approach for the preparation of enriched herbal formulations was described and their potential applications including wound healing and antioxidant activity (cell based and cell free) were investigated via in vitro cell culture studies. Nigella sativa oil was enriched with Calendula officinalis extract and lipoic acid capped gold nanoparticles (AuNP-LA) using nanoemulsion systems. The combination of these bio-active compounds was used to design oil in water (O/W) and water in oil (W/O) emulsions. The resulted emulsions were characterized by particle size measurements. The phenolic content of each nanoemulsion was examined by using both colorimetric assay and chromatographic analyses. Two different methods containing cell free chemical assay (1-diphenyl-2-picrylhydrazyl method) and cell based antioxidant activity test were used to evaluate the antioxidant capacities. In order to investigate the bio-activities of the herbal formulations, in vitro cell culture experiments, including cytotoxicity, scratch assay, antioxidant activity and cell proliferation were carried out using Vero cell line as a model cell line. Furthermore, to monitor localization of the nanoemulsions after application of the cell culture, the cell images were monitored via fluorescence microscope after FITC labeling. All data confirmed that the enriched N. sativa formulations exhibited better antioxidant and wound healing activity than N. sativa emulsion without any enrichment. In conclusion, the incorporation of AuNP-LA and C officinalis extract into the N. sativa emulsions significantly increased the bio-activities. The present work may support further studies about using the other bio-active agents for the enrichment of herbal preparations to strengthen their activities. (C) 2014 Elsevier B.V. All rights reserved.
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    Electrochemical deposition of polypeptides: bio-based covering materials for surface design
    (Royal Soc Chemistry, 2014) Akbulut, Huseyin; Yavuz, Murat; Guler, Emine; Demirkol, Dilek Odaci; Endo, Takeshi; Yamada, Shuhei; Timur, Suna
    A simple and efficient approach for the electrochemical deposition of polypeptides as bio-based covering materials for surface design is described. The method involves N-carboxyanhydride (NCA) ring-opening polymerization from its precursor to form a thiophene-functionalized polypeptide macromonomer (T-Pala), followed by electropolymerization. The obtained conducting polymer, namely polythiophene-g- polyalanine (PT-Pala), was characterized and utilized as a matrix for biomolecule attachment. The biosensing applicability of PT-Pala was also investigated by using glucose oxidase (GOx) as a model enzyme to detect glucose. The designed biosensor showed a very good linearity for 0.01-1.0 mM glucose. Finally, the antimicrobial activities of newly synthesized T-Pala and PT-Pala were also evaluated by using the disc diffusion method.
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    Herbal infusions of black seed and wheat germ oil: Their chemical profiles, in vitro bio-investigations and effective formulations as Phyto-Nanoemulsions
    (Elsevier Science Bv, 2015) Gumus, Z. Pinar; Guler, Emine; Demir, Bilal; Barlas, F. Baris; Yavuz, Murat; Colpankan, Dilara; Senisik, A. Murat
    The reported studies related to black seed oil (BSO) and wheat germ oil (WGO) have illustrated that they have a wide range of biological activities. Therefore, enhancing the amount of bio-active compounds that caused higher cell based anti-oxidative effect as well as cell proliferation, etc. in seed oils, infusion of crude plant material has been gained importance as a traditional technique. Herein, we accomplished the infusion of Calendula flowers that also contains many phyto-constituents into BSO and WGO. After the infusion of oils, the change of phytochemical amount was investigated and evaluated according to the oils by chromatography, radical scavenging activity. Subsequently, for investigating the biological impact upon live cells, cytotoxicity, cell-based antioxidant capacity, wound healing and radioprotective activity were tested with monkey kidney fibroblast like cells (Vero) and HaCaT keratinocytes. In vitro cell based experiments (wound healing and radioprotective activity) confirmed that Calendula infused BSO and WGO have greater bio-activity when compared to those plain forms. The herbal oils prepared with an effective extraction technique were incorporated into nanoemulsion systems which will be then called as 'Phyto-Nanoemulsion'. After herbal oil biomolecules were encapsulated into nanoemulsion based delivery systems, the designed formulations were investigated in terms of biological activities. In conclusion, these preparations could be a good candidate as a part of dermal cosmetic products or food supplements which have the therapeutic efficiency, especially after radio- or chemotherapy. (C) 2015 Elsevier B.V. All rights reserved.
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    Niosomes of Nerium oleander extracts: In vitro assessment of bioactive nanovesicular structures
    (Elsevier, 2017) Gunes, Aybike; Guler, Emine; Un, Rabia Nur; Demir, Bilal; Barlas, F. Baris; Yavuz, Murat; Coskunol, Hakan
    Niosomes are known as non-ionic surfactant-based vesicles and have been used quite a lot for medical applications as a novel drug delivery system in recent years. Herein we describe, the preparation and characterization of niosomes containing oleander (Nerium oleander) (ONs) extract as the herbal compound. In this context, niosomal formulations of two different extracts obtained from oleander roots were prepared by a thin film hydration technique using Tween 60 (non-ionic surfactant) with a cholesterol mixture at 1:1 M ratio. These vesicular structures were characterised by various techniques such as atomic force microscopy, zeta potential and dynamic light scattering size measurements. ONs vesicles are less than 100 nm in size with a good physical stability more than 50 days. Initially, total phenolic and flavonoid contents and antioxidant activities of the extracts were investigated. The methanol extract of oleander roots (MOE) showed higher polyphenolic content and exhibits a better antioxidant activity in compared to the hydro-methanol (20% methanol) extract (MOWE). Total phenolic contents in the MOE and MOWE were calculated as 64.51 +/- 0.945 mu g/mg and 65.05 +/- 0.37 mu g/mg gallic acid equivalents, respectively. Encapsulation efficiencies of the vesicles were found as 16.2% for MON (contain MOE) and 13.24% for MWON (contain MOWE). The significant linear correlation Was confirmed between the antioxidant activity and total phenolic content of extracts as well as ONs. Cell based cytotoxic activities of methanol extract and MON formulations were also assessed via KIT assay using Hela and A549 cell lines. (C) 2016 Elsevier B.V. All rights reserved.
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    Phyto-Niosomes: In Vitro Assessment of the Novel Nanovesicles Containing Marigold Extract
    (Taylor & Francis As, 2015) Un, Rabia Nur; Barlas, F. Baris; Yavuz, Murat; Seleci, Didem Ag; Seleci, Muharrem; Gumus, Z. Pinar; Guler, Emine
    Herbal compounds, so-called phytoconstituents, illustrate poor absorption by living cells. Phytosomes are advanced form of herbal compounds that show higher absorption rate and bioavailability, which results better than conventional plant extracts. Niosomes, which are made of nonionic surfactants, create better chemical and stability conditions besides lipid vesicles. This study covers the preparation, characterization and cell culture applications of phyto-niosomes of Marigold extract. Before the encapsulation process, extracts of selected plants were prepared and the extract that presents best bioactivity was chosen. The resulting phyto-niosomes were characterized and their biological activities including cytotoxicity, wound healing and antioxidant activity were investigated.
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    Ruthenium (II) complexes of thiosemicarbazone: Synthesis, biosensor applications and evaluation as antimicrobial agents
    (Elsevier Science Bv, 2014) Yildirim, Hatice; Guler, Emine; Yavuz, Murat; Ozturk, Nurdan; Yaman, Pelin Kose; Subasi, Elif; Sahin, Elif
    A conformationally rigid half-sandwich organoruthenium (II) complex [(eta(6)-p-cymene)RuClTSCN-S]Cl, (1) and carbonyl complex [Ru(CO)Cl(PPh3)(2)TSCN-S] (2) have been synthesized from the reaction of [{(eta(6)-p-cymene) RuCl}(2)(mu-Cl)(2)] and [Ru(H)(Cl)(CO)(PPh3)(3)] with thiophene-2-carboxaldehyde thiosemicarbazon (TSC) respectively and both novel ruthenium (II) complexes have been characterized by elemental analysis, FT-IR and NMR spectroscopy. The peripheral TSC in the complexes acts as an electrochemical coupling unit providing the ability to carry out electrochemical deposition (ED) and to form an electro-deposited film on a graphite electrode surface. The biosensing applicability of complexes 1 and 2 was investigated by using glucose oxidase (GOx) as a model enzyme. Electrochemical measurements at -0.9 V versus Ag/AgCl electrode by following the ED Ru(II) reduction/oxidation due to from the enzyme activity, in the presence of glucose substrate. The designed biosensor showed a very good linearity for 0.01-0.5 mM glucose. The in vitro antimicrobial activities of complexes 1 and 2 were also investigated against nine bacterial strains and one fungus by the disc diffusion test method. No activity was observed against the Gram-negative strains and fungus, whereas complex 1 showed moderate antibacterial activities against Gram-positive bacterial strains. (C) 2014 Elsevier B.V. All rights reserved.