Scopus İndeksli Yayınlar Koleksiyonu / Scopus Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7148
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Article Citation - WoS: 3Citation - Scopus: 2Design and Evaluation of Novel Poly (Vinyl Alcohol)-Based Electrospun Nanofibers Bearing Quaternized Zinc Phthalocyanine with Improved Antibacterial Efficiency(Elsevier Sci Ltd, 2025) Yavuz, Ozgur; Cakir, Neslihan Turhan; Alcay, Yusuf; Kadi, Ilayda Hizir; Kahveci, Muhammet U.; Yilmaz, Ismail; Altinkok, CagatayElectrospinning of macrocyclic compounds offers a versatile route to functional nanofibers for biomedical applications. However, the small molecular size and tendency to aggregate of such compounds often preclude their direct processing. Herein, we report the fabrication of poly(vinyl alcohol) (PVA) nanofibers uniformly embedded with a dimethylaminophenyl-functionalized, quaternized zinc phthalocyanine derivative (Q-DMAPZnPc) via a straightforward aqueous electrospinning process. Successful incorporation of Q-DMAPZnPc into the PVA matrix was confirmed by FT-IR and 1H NMR spectroscopies. SEM revealed bead-free fibers with average diameters decreasing from 152 +/- 20 nm to 110 +/- 23 nm as the Q-DMAPZnPc loading increased. Water contact angle, thermogravimetric, and differential scanning calorimetry analyses demonstrated that both hydrophilicity and thermal stability of the fibers improved with higher Q-DMAPZnPc content. The singlet oxygen quantum yield (Phi Delta) of the PVA-Q-DMAPZnPc (5 wt %) was measured as 0.35. Importantly, quaternization endowed the fibers with potent antibacterial activity: under visible-light irradiation, PVA-Q-DMAPZnPc mats achieved significant log-reduction against both Gram-negative (Escherichia coli, Salmonella typhimurium) and Gram-positive (Staphylococcus aureus, Bacillus cereus) pathogens, markedly outperforming neat PVA controls. These findings highlight the promise of Q-DMAPZnPc-loaded PVA nanofibers as light-activated antimicrobial platforms for next-generation therapeutic and protective materials.Article Citation - WoS: 1The Impact of Oxygen and Antimicrobial Tea Tree Oil Carrying Biomaterial on Cell Viability Under Hypoxic Conditions(Wiley, 2025) Demir, Yagmur Damla; Tepeli, Dilek; Guvensen, Mahmut Deniz; Soyer, Ferda; Akin, Ozlem; Kehr, Nermin SedaTraditional wound treatment involves protecting the wound with dressing and administering antibiotics to prevent tissue infection due to bacteria. However, these methods are inadequate due to the side effects of antibiotics on healthy cells and microbial resistance to antibiotics. Therefore, new strategies involving the application of natural resources such as essential oils as antimicrobial agents in combination with biomaterials as wound dressings have been tested in the treatment of wounds. Furthermore, oxygen (O2)-releasing biomaterials have attracted great interest due to the important role of O2 in wound healing processes. However, the co-application of O2 and essential oil as antimicrobial and cell-promoting agents has not been studied. In this context, we report a novel biomaterial capable of co-delivering O2 and natural antimicrobial tea tree oil (TTO) for 15 and 5 days, respectively. The biomaterial consists of an alginate scaffold (Alg-PMOF-O) containing O2-carrying nanomaterial, laponite and TTO. In vitro bacterial experiments have shown that O2 release from Alg-PMOF-O is an additional parameter acting as an antibacterial agent to inhibit bacterial growth but is not sufficient alone to inhibit bacteria. 5 mu L of TTO in Alg-PMOF-O is necessary to suppress both E. coli and S. aureus over a 1-day incubation period. The effect of TTO and O2 alone or in combination on cell viability is examined using WST-1 and PrestoBlue assays. According to the WST-1 and PrestoBlue tests, the combined application of TTO and O2 does not show any toxic effect on fibroblast cells under normoxic conditions during the 5-day incubation period. Under hypoxic conditions, the WST-1 test shows no toxic effect after only 1 day of incubation, while the PrestoBlue test shows no toxicity under hypoxia during both 1 and 5 days of incubation. On the other hand, the combined application of TTO and O2 indicates toxic effects on cancer Malme-3M cells during both normoxic and hypoxic conditions over 1 and 5 days of incubation. This effect is confirmed by both the WST-1 and PrestoBlue tests. The overall results demonstrate that Alg-PMOF-O exhibits antibacterial activity while having a lower toxic effect on fibroblasts under hypoxic conditions, and therefore has potential for use as wound dressing.Article Citation - WoS: 5Citation - Scopus: 5Effects of Diborolane Containing Oxo/Amine Compounds on Clinically Important Bacteria and Candida Species(Elsevier B.V., 2024) Şahin,Y.; Çoban,E.P.; Özgener,H.; Bıyık,H.H.; Sevincek,R.; Aygün,M.; Gürbüz,B.A good yield of 1,2-diborolanderivatives 2-8 was obtained from the reaction of 1,2-dichloro-1,2-diborolane 1 and R2NLi/ArNHLi/PhOLi/H2O. The structures of these new derivatives were characterized by nuclear magnetic resonance spectroscopy. The molecular structures of 4 and 7a were also determined using single-crystal X-ray diffraction. The antimicrobial activities of synthesized compounds were tested against clinically important Gram-positive, Gram-negative bacteria, and Candida species. The most effective substances were found to be compounds 2, 3, 4, 6 and 8 among the tested compounds. Therefore, the activity of these substances were investigated against Staphylococcus aureus ATCC 43300 and Enterococcus faecalis ATCC 51575, which form biofilms and have antibiotic resistance. Compound 2, 6 and 8 appears to be a promising candidate for potential antibacterial agents against these bacterial strains, especially given its potent activity against biofilm-forming and antibiotic resistant strains. The results indicate that these new materials will be evaluated as potential drugs against infectious diseases in the future. © 2024 Elsevier B.V.Article Citation - WoS: 40Citation - Scopus: 44Plasmon-Enhanced Photocatalytic and Antibacterial Activity of Gold Nanoparticles-Decorated Hematite Nanostructures(Elsevier Ltd., 2021) Emre, Alp; İmamoğlu, Rizvan; Savacı, Umut; Turan, Servet; Kazmalı, M. Kürşat; Genç, AzizHematite (alpha-Fe2O3) nanoparticles have received significant attention from the researchers due to their favorable and desirable properties in diverse applications. In the present study, single-crystalline hematite pseudo-nanocubes and porous nanorods were synthesized by the hydrothermal route without the usage of any surfactant agents, which were then decorated with gold nanoparticles hidrothermally in an aqueous solution in order to increase the solar energy conversion efficiency. The photocatalytic activities of synthesized nanoparticles were studied against Rhodamine B (RhB) under the illumination of AM 1.5 solar simulator. The excellent photocatalytic efficiency was obtained by changing morphological features of hematite nanostructures, along with the photocatalytic performance enhancement up to 25% thanks to the surface plasmon resonances for the gold nanoparticles-decorated hematite nanostructures. For instance, gold-nanoparticles decorated hematite pseudo-nanocubes almost completely degraded all the RhB after 30 min of illumination. It was also observed that all hematite products, with and without gold decoration, exhibited an impressive antibacterial effect and showed the lethal effect in E.coli. The same nanoparticles being photocatalytically active for organic pollutant degradation and having antibacterial effect may have a good potential for waste water remediation applications. (C) 2020 Elsevier B.V. All rights reserved.Article Citation - WoS: 17Citation - Scopus: 20Preparation and Characterization of Antibacterial Cobalt-Exchanged Natural Zeolite/Poly(vinyl Alcohol) Hydrogels(Springer Verlag, 2014) Narin, Güler; Bulut Albayrak, Çisem; Ülkü, SemraIn the present study, potential application of the local clinoptilolite-rich natural zeolite in formulation of antibacterial hydrogels was investigated. The zeolite powder exchanged with cobalt(II) ions was used in preparation of the zeolite/poly(vinyl alcohol) hydrogel films in different amounts. The films were physically crosslinked by the freezing-thawing method and characterized for their crystallinity, surface and cross sectional morphology, chemical composition, thermal behaviour, mechanical properties, swelling and dissolution behaviours, and antibacterial activities against a Gram-negative bacteria. The films with 0.48 wt% and higher cobalt-exchanged zeolite contents showed antibacterial activity. Addition of the zeolite powder in the formulations did not cause significant changes in the other properties of the films.Article Citation - WoS: 25Citation - Scopus: 29Antibacterial Properties of Silk Fibroin/Chitosan Blend Films Loaded With Plant Extract(Korean Fiber Society, 2010) Başal, Güldemet; Altıok, Duygu; Bayraktar, OğuzThe silk fibroin (SF)/chitosan (CHI) blend films were prepared by dissolving them in formic acid. The morphology of the films was examined by scanning electron microscopy (SEM). The roughness of the membranes was determined by atomic force microscopy (AFM). These films were treated with the extracts of Pistacia terebinthus, Pistacia lentiscus, and Hypericum empetrifolium. Folin-Ciocalteu assay was used to determine the amount of total phenols adsorbed on these blend films. The antibacterial properties of films were tested using disc diffusion and turbidity measurement methods against Escherichia coli and Staphylococcus epidermidis. The release of adsorbed phenolics from the film surface resulted in antibacterial properties. © The Korean Fiber Society and Springer Netherlands 2010.Article Citation - WoS: 6Citation - Scopus: 10Surface Chemistry Dependent Toxicity of Inorganic Nanostructure Glycoconjugates on Bacterial Cells and Cancer Cell Lines(Elsevier, 2023) Sancak, Sedanur; Yazgan, İdris; Bayarslan, Aslı Uğurlu; Ayna, Adnan; Evecen, Senanur; Taşdelen, Zehra; Gümüş, Abdurrahman; Sönmez, Hamide Ayçin; Demir, Mehmet Ali; Demir, Sosin; Bakar, Fatma; Dilek Tepe, HafizeSurface functionalized nanostructures have outstanding potential in biological applications owing to their target-specific design. In this study, we utilized laboratory synthesized carbohydrate-derivatives (i.e., galactose, mannose, lactose, and cellobiose derivatives) for aqueous one-pot synthesis of gold (Au) and silver (Ag) nanostructure glycoconjugates (NSs), and iron metal-organic framework glycoconjugates (FeMOFs). This work aims to test whether differences in the surface chemistry of the inorganic nanostructures play roles in revealing their toxicities towards bacterial cells and cancerous cell lines. As of the first step, biological activity of AuNSs, AgNSs, and FeMOFs were tested against a variety of gram (−) and gram (+) bacterial strains, where AgNSs possessed moderate to high antibacterial activities against all the tested bacterial strains, while AuNSs and FeMOFs showed their bacterial toxicity mostly depending on the strain. Minimum inhibitory concentration (MIC) and Minimum bactericidal concentration (MBC) determination studies were performed for the nanostructure glycoconjugates, for which μg/mL MBC values were obtained such as (Cellobiose p-aminobenzoic acid_AgNS) CBpAB_AgNS gave 50 μg/mL MBC value for P.aeruginosa and S.kentucy. The activity of selected sugar ligands and corresponding glycoconjugates were further tested on MDA-MB-231 breast cancer and A549 lung cancer cell lines, where selective anticancer activity was observed depending on the surface chemistry as well. Besides, D-penicillamine was introduced to galectin specific sugar ligand coated AuNS glycoconjugates, which showed very strong anticancer activities even at low doses. Overall, the importance of this work is that the surface chemistry of the inorganic nanostructures can be critical to reveal their toxicity towards bacterial cells and cancerous cell lines.