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https://hdl.handle.net/20.500.12587/8642

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The reactions of N$_{3}$P$_{3}$Cl$_{6}$ with monodentate and bidentate ligands: the syntheses and structural characterizations, in vitro antimicrobial activities, and DNA interactions of 4-fluorobenzyl(N/O)spirocyclotriphosphazenes
(Tubitak Scientific & Technological Research Council Turkey, 2017) Okumuş, Aytuğ; Elmas, Gamze; Kilic, Zeynel; Ramazanoglu, Nagehan; Açık, Leyla; Türk, Mustafa; Akça, Gülçin
The Cl replacement reactions of 4-fluorobenzyl(N/O)spirocyclotriphosphazene (2) with excess monoamines led to the formation of 4-fluorobenzylspiro(N/O)tetraaminocyclotriphosphazenes (2a-2d). The partly substituted dispiro 3b and dispiro 3c and fully substituted trispirocyclotriphosphazenes (trans 4a, cis 4c, 4d, and 4e) were obtained, respectively, from the reactions of 2 with one equimolar and two equimolar amounts of diamines, aminoalcohol, and diols. Although efforts were made for the separation of the cis/trans and optical isomers of the dispiro phosphazenes, only one set of diastereomers (RR/RS or SS/SR) of dispiro 3b and dispiro 3c was isolated, respectively. The P-31 NMR spectral data of the other dispiro phosphazenes were evaluated from the P-31 NMR spectra of the reaction mixtures. The reactions of 2 with excess N-methylethylenediamine gave trans 4a as a racemic mixture. While trans 4b (racemic) and cis 4b (meso) occurred from the reaction of 2 with excess N-methyl-1,3-propanediamine, they were not isolated separately. Some of the phosphazenes were screened against bacteria and fungi. The activities of the compounds against anaerobic and microaerophilic gram-negative bacteria were evaluated. It was found that compounds 2, 2b, and trans 4a exhibited tolerable toxic effects on fibroblast cells and had the highest toxicity against MCF-7 cells.
The dye adsorption and antibacterial properties of composite polyacrylamide cryogels modified with ZnO
(Elsevier Science Inc, 2021) İnal, Murat; Erduran, Nuran; Gökgöz, Murat
The present study aimed to modify the surface of polyacrylamide cryogels (PAC) with ZnO nanorods (ZNR) to provide them with antibacterial properties. The synthesized ZNR-modified composite PAC (ZMC) characterized by AAS, FTIR, SEM, XRD, XPS, BET surface analysis and TGA studies. A study of the adsorption of Orange G (OG) and antibacterial effect was performed on the synthesized ZMC. The highest adsorption capacity was determined to be at a dye concentration of 142.79 mg/g at 400 ppm, and a pH of 2. From the data obtained, it was found that adsorption fitted the pseudo-second-order kinetic model and Freundlich isotherm. Modified cryogels could be desorbed in a very short time-such as 30 min-and reused approximately twenty times with 80% efficiency. While ZMC cryogels did not show antibacterial activity in the dark, inhibition percentages were determined as 99.79 +/- 3.94% and 99.81 +/- 1.76%, at 1.78 mg/mL cryogel application, MIC90 values were determined as 1.589 +/- 0.063 and 0.660 +/- 0.028 mg/ mL for Escherichia coli, and Staphylococcus aureus, respectively under visible light. The results showed that the composite cryogels obtained had a very high potential to be applied both in the removal of dyes from wastewater and in the purification of microorganism-contaminated water. (c) 2021 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.
The development and characterization of electrospun gelatin nanofibers containing indomethacin and curcumin for accelerated wound healing
(Elsevier, 2022) Gulsun, Tugba; İnal, Murat; Akdağ, Yağmur; İzat, Nihan; Öner, Levent; Şahin, Selma
Nanofibers are frequently investigated to facilitate wound healing. In this study, gelatin nanofibers were produced that are biodegradable and biocompatible. Indomethacin and curcumin were added to the formulation to add antioxidant, anti-inflammatory, analgesic properties to the nanofibers. The nanofibers were characterized by differential scanning calorimetry (DSC), scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR). Cell viability, proliferation, tensile strength, content uniformity, antioxidant activity, drug release studies were investigated. DSC and FTIR analyses showed that indomethacin and curcumin were coated with the gelatin in the nanofibers. SEM studies demonstrated that smooth and homogeneous nanofibers were produced in the range 260-360 nm. Tensile strength values decreased with the addition of indomethacin and curcumin to the gelatin nanofiber, while the antioxidant activity results showed that the wound dressings can remove reactive oxygen species. There was no significant decrease in cell viability as a result of adding indomethacin and curcumin to the nanofibers. It was predicted that with a rapid release of indomethacin from the nanofibers, an analgesic effect will be obtained first and then an antioxidant effect will be seen from the longterm release of curcumin. Consequently, it was shown that the nanofibers produced can be used safely and effectively as an antioxidant wound dressing material.
The comparison of contribution of GO and rGO produced by green synthesis to the properties of CMC-based wound dressing material
(Elsevier, 2024) Karaca, Özge Gülüzar; Moran, Büşra; Türk, Mustafa; Bal-Öztürk, Ayça; Izbudak, Burçin; Aydin, Yasar Andelib; Utkan, Güldem
Herein, GO (graphene oxide) or rGO (reduced graphene oxide) which is produced by the green synthesis method using plant extract (Laurus nobilis) was incorporated into a polymeric structure consisting of carboxymethyl cellulose (CMC) and polyethylene glycol (PEG) to produce a wound dressing material with enhanced mechanical and electrical properties. The effect of GO and rGO on the wound dressing features of the produced materials was investigated and compared to each other. Conductivity tests demonstrated that rGO contributed more significantly to the electrical conductivity than GO. While rGO-CMC/PEG/CA reached 3.01 x 10-6 S.cm- 1 as the conductivity value, that of GO-CMC/PEG/CA was determined as 0.85 x 10-6 S.cm- 1. As for the mechanical tests, it was seen that rGO achieved the best results in terms of elastic modulus (588.62 N/mm2), tensile strength (94.95 MPa) and elongation at break (17.64 %) compared to GO reinforced and pure hydrogel. Curcumin and ascorbic acid were used for antibiotic-free wound treatment and their release kinetics were also modeled. The results showed that rGO reinforced hydrogel provided a more controlled release. All results assured that both the produced GO reinforced and especially rGO reinforced hydrogels could be utilized as modern wound dressing materials with suitable properties to achieve remarkable results for wound healing.
The comparative reactions of 2-cis-4-ansa and spiro cyclotetraphosphazenes with difunctional ligands: Structural and stereogenic properties, electrochemical, antimicrobial and cytotoxic activity studies
(Wiley, 2021) Okumuş, Aytuğ; Elmas, Gamze; Kilic, Zeynel; Binici, Arzu; Ramazanoglu, Nagehan; Açık, Leyla; Coşut, Bünyemin
In this study, two kinds of compounds, namely, mono-ferrocenyl-2-cis-4-dichloro-ansa- (2,4-ansa; 3) and mono-ferrocenyl-spiro- (spiro; 4) hexachlorocyclotetraphosphazenes, were obtained by the Cl replacement reaction of N4P4Cl8 (1) with an equimolar amount of sodium 3-(N-ferrocenylmethylamino)-1-propanoxide (2). The reactions of 2,4-ansa (3) with excess diamines and dialkoxides resulted in the formation of ansa-cyclotetraphosphazenes (3a-3e). Spiro (4) was reacted with excess diamines and dialkoxides to give the mono-ferrocenyl-spiro-cyclotetraphosphazenes (4a-4d). Although 2,4-ansa (3) produced the dispiro (3a) with N-(4-fluorobenzyl)-N '-methylethane-1,2-diamine, it afforded both monospiro (3b) and dispiro (3c) with N-(4-fluorobenzyl)-N '-methylpropane-1,3-diamine. However, spiro (4) yielded a trispiro (4a) with N-(4-fluorobenzyl)-N '-methylethane-1,2-diamine and 2,6-dispiro (4b) with N-(4-fluorobenzyl)-N '-methylpropane-1,3-diamine. The structures of the phosphazenes were elucidated by FTIR, ESI-MS and/or HRMS, spectroscopic and crystallographic (for 3f and 4b) data. Furthermore, the electrochemical findings of cyclotetraphosphazenes exhibited electrochemically reversible one-electron oxidation of Fe-redox centre. As an example, the chirality of 3c was investigated by P-31 NMR spectroscopy on the addition of (R)-(+)-2,2,2-trifluoro-1-(9 '-anthryl)-ethanol, chiral solvating agent (CSA). The circular dichroism (CD) (for 3d and 3e), HPLC (for 3d, 3e and 3f) and X-ray (for 3f) display that these compounds have chirality (RS ' or SR ') in the solution and solid state. This paper also focuses on the antimicrobial activities, the interactions with pBR322 DNA, in vitro anticancer activity against L929 fibroblast and MCF7 breast cells, and antituberculosis activity against Mycobacterium tuberculosis H37Rv of the cyclotetraphosphazenes.
Synthesis of carrageenan coated silver nanoparticles by an easy green method and their characterization and antimicrobial activities
(Springer, 2021) Gün Gök, Zehra; Karayel, Mine; Yigitoglu, Mustafa
The aim of the present work was to synthesize carrageenan coated silver nanoparticles (CA-AgNPs) using carrageenan as reducing and stabilizing agent. For this purpose, 10 mL of 0.35% (w/v) carrageenan solution was mixed with 10 mL AgNO3 solution at different concentrations (1, 5 and 10 mM), and the resulting mixture was stirred at 100 degrees C at high speed for 2 h. The formation of CA-AgNPs was proven with the surface plasmon peaks observed at approximately 420 nm. The sizes and zeta potentials of CA-AgNPs were determined by Zeta-Sizer. Negative zeta potentials of CA-AgNPs indicated that the obtained AgNPs were stable. With scanning electron microscope (SEM) and transmission electron microscope analysis, it was seen that CA-AgNPs have spherical structure. According to the energy dispersion spectrometer analysis based on SEM images, it was observed that the samples were elementally composed of carbon, oxygen, sulfur, potassium and silver. The chemical structures of CA-AgNPs were determined by Fourier transform infrared spectroscopy, and it was proved that the carbonyl and OH groups of carrageenan were involved in formation and stabilizing of AgNPs, respectively. According to thermal gravimetric analysis, it has been observed that CA-AgNPs were thermally more stable than pure carrageenan. Antibacterial activity of CA-AgNPs against gram-positive and gram-negative bacteria was investigated with agar well diffusion and liquid test. It has been observed that CA-AgNPs synthesized with 1 mM AgNO3 did not have an antibacterial activity on Escherichia coli and Staphylococcus aureus. Inhibition zones of varying diameters were observed in the 5 mM and 10 mM S-AgNPs groups. The synthesized CA-AgNPs (5 and 10 mM) have the capacity to be used in wound dressing materials or topical agents applied to burns and wounds due to their antibacterial effects and stability.
Synthesis and characterization of polyethyleneimine/silk fibroin/gold nanoparticle nanocomposites: Potential application as a gene carrier in breast cancer cell lines
(Pergamon-Elsevier Science Ltd, 2023) Tunalı, Beste Çağdaş; Aktürk, Ömer; Şahingöz, Durukan; Türk, Mustafa; Keskin, Ayten Çelebi
There is a need in advancing the design of non-viral gene carriers, thus herein using the pulsed laser ablation in liquid (PLAL) technique, polyethyleneimine-capped gold nanoparticles (PEI-AuNPs) were synthesized and then combined with Bombyx mori silk fibroin (SF) to form the nanocomposites (PEI-SF-AuNPs). After the characterization analyses were carried out, PEI-AuNPs and PEI-SF-AuNPs were tested for their in vitro biocompatibility in MCF-7 and MDA-MB231 breast cancer cells. Finally, the transfection capability of the selected group was observed. PEI capping enabled the cationic modification of the AuNP surface and SF reduced the surface charge (from 35 to 4 mV). PEI-AuNPs were highly monodispersed in shape and size (8-9 nm). The nanoparticle group synthesized in 5% (w/v) PEI concentration (PEI-AuNP5) had increased cytotoxicity as compared to the group synthesized in 1% (w/v) PEI concentration (PEI-AuNP1), but the conjugation of SF with PEI-AuNPs alleviated this cytotoxic tendency significantly. The group (PEI-AuNP1) with the most negligible cytotoxicity proved to be successful in the transfection of siRNA analog, i.e., siGLO green transfection indicator. Overall, the PEI-AuNP1 nanocomposites could be suggested as potent siRNA carriers due to the above beneficial properties in genebased breast cancer therapies.
Synthesis and characterization of polyvinyl alcohol-silk sericin nanofibers containing gelatin-capped silver nanoparticles for antibacterial applications
(Springer, 2022) Gök, Zehra Gün
In this study, nanofiber surfaces were produced from a mixture of polyvinyl alcohol and silk sericin protein (PVA:SS) containing gelatin-coated silver nanoparticles (G-AgNPs) by electrospinning. For preparation of G-AgNPs, gelatin solution (1%, w/v) was mixed with 5 mM of AgNO3 solution and the mixture was heated and stirred for 2 h. AgNPs production has been observed with the brown color change that occurred in the solution. The absorbance of G-AgNPs was measured with a UV-Vis spectroscopy in the 300-700 nm range, and it was proved that AgNPs were formed with the surface plasmon resonance peak observed at 420 nm. Field emission scanning electron microscopy (FESEM) and energy-dispersive X-ray analysis (EDS) analyses revealed that G-AgNPs were in spherical form and contained C, H, N, Ag elements in their structures, respectively. Antibacterial activity of the synthesized of G-AgNPs was shown with agar well diffusion test against to Escherichia coli and Staphylococcus aureus bacteria. In the second stage of the study, PVA:SS solutions were turned into nanofibers by electrospinning at certain conditions. G-AgNPs solutions were added in 3 different ratios of 10, 20 and 30% by volume to PVA:SS solutions, and these mixtures were turned into nanofibers with the same conditions. It has been shown by Fourier transform infrared spectroscopy (FTIR) analyses that the nanofiber surfaces obtained were composed of PVA:SS blend. The morphologies of nanofiber surfaces were investigated by FESEM analysis, and compared to PVA nanofibers collected alone, the fiber diameters of the groups containing PVA, sericin and G-AgNPs were found to be much lower. The presence of silver in nanofibers containing G-AgNPs was proven by EDS and X-ray fluorescence analyses. The thermal properties of nanofiber surfaces were investigated by thermogravimetric analysis, and it was observed that the thermal stability of nanofiber surfaces increased with the addition of sericin and G-AgNPs to PVA. Then, liquid medium tests were performed for finding the antibacterial activity of nanofiber surfaces containing various proportions of G-AgNPs on E. coli and S. aureus bacteria, and it was observed that nanofiber surfaces containing certain amounts of G-AgNPs inhibited the growth of both bacteria. It is thought that the functional and antibacterial surfaces obtained in the study will have the capacity to be used in many different areas such as wound dressing material.
Removal of anionic dyes with glycidyl methacrylate-grafted polyethylene terephthalate (PET) fibers modified with ethylenediamine
(Springer, 2021) Bozkaya, Ogün; Günay, Kübra; Arslan, Metin; Gün Gök, Zehra
In this work, the epoxy groups of poly (ethylene terephthalate) PET copolymers grafted with glycidyl methacrylate (GMA) were modified with ethylenediamine (EDA) to form exclusive adsorbent for removal of congo red (CR) and acid violet7 (AV-7) in the aqueous environment. The graft copolymers (GMA-g-PET) were synthesized with different grafting yield by a radical polymerization process with using benzoyl peroxide (Bz(2)O(2)) as radical initiator. Amination of GMA-g-PET fibers using EDA was studied in different solvents, and maximum yield (w/w %) was obtained in the toluene. The grafted and modified fibers were analyzed by CHNS organic elemental analyzer, scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy and nuclear magnetic resonance spectroscopy (C-13-NMR). By SEM analysis, the morphological changes have been shown after grafting. The chemical changes after grafting and addition of EDA to the fibers have been proven with FTIR, NMR and elemental analysis. The thermal properties of the grafted and aminated fibers were researched with thermogravimetric analysis and differential scanning calorimeter analysis. The removal of dyes by the EDA-GMA-g-PET fibers was investigated in aqueous medium at different conditions. Optimum conditions of different parameters such as pH of medium, graft yield of GMA on the fibers, adsorption duration, initial concentration of dye molecules and effect of graft yield on amination reaction were examined. The optimum pH of CR and AV-7 removal was found 5 and 3, respectively. The removal yield was found about 100% for both dyes while initial concentration of dyes was changed from 10 to 400 mg/L. Adsorbed dyes with the fibers were desorbed with 1 M NaOH at room conditions.
Production of Reduced Graphene Oxide by Using Three Different Microorganisms and Investigation of Their Cell Interactions
(Amer Chemical Soc, 2023) Utkan, Güldem; Yumuşak, Görkem; Tunalı, Beste Çağdaş; Öztürk, Tarık; Türk, Mustafa
Despite the hugeand efficient functionalities of reduced grapheneoxide (RGO) for bioengineering applications, the use of harsh chemicalsand unfavorable techniques in their production remains a major challenge.Microbial production of reduced graphene oxide (RGO) using specificbacterial strains has gained interest as a sustainable and efficientmethod. The reduction of GO to RGO by selected bacterial strains wasachieved through their enzymatic activities and resulted in the removalof oxygen functional groups from GO, leading to the formation of RGOwith enhanced structural integrity. The use of microorganisms offersa sustainable approach, utilizing renewable carbon sources and mildreaction conditions. This study investigates the production of RGOusing three different bacterial strains: Lactococcuslactis (L. Lactis), Lactobacillus plantarum (L. plantarum), and Escherichia coli (E. coli) and evaluates its toxicity for safe utilization.The aim is to assess the quality of the produced RGO and evaluateits toxicity for potential applications. Thus, this study focusedon the microbial production of reduced graphene oxides well as theinvestigation of their cellular interactions. Graphite-derived grapheneoxide was used as a starting material and microbially reduced GO productswere characterized using the FTIR, Raman, XRD, TGA, and XPS methodsto determine their physical and chemical properties. FTIR shows thatthe epoxy and some of the alkoxy and carboxyl functional groups werereduced by E. coli and L. lactis, whereas the alkoxy groups were mostlyreduced by L. plantarum. The I (D)/I (G) ratio fromRaman spectra was found as 2.41 for GO. A substantial decrease inthe ratio as well as defects was observed as 1.26, 1.35, and 1.46for ERGO, LLRGO, and LPRGO after microbial reduction. The XRD analysisalso showed a significant reduction in the interlayer spacing of theGO from 0.89 to 0.34 nm for all the reduced graphene oxides. TGA resultsshowed that reduction of GO with L. lactis provided more reduction than other bacteria and formed a structurecloser to graphene. Similarly, analysis with XPS showed that L lactisprovides the most effective reduction with a C/O ratio of 3.70. Inthe XPS results obtained with all bacteria, it was observed that theC/O ratio increased because of the microbial reduction. Toxicity evaluationswere performed to assess the biocompatibility and safety of the producedRGO. Cell viability assays were conducted using DLD-1 and CHO celllines to determine the potential cytotoxic effects of RGO producedby each bacterial strain. Additionally, apoptotic, and necrotic responseswere examined to understand the cellular mechanisms affected by RGOexposure. The results indicated that all the RGOs have concentration-dependentcytotoxicity. A significant amount of cell viability of DLD-1 cellswas observed for L. lactis reducedgraphene oxide. However, the highest cell viability of CHO cells wasobserved for L. plantarum reduced grapheneoxide. All reduced graphene oxides have low apoptotic and necroticresponses in both cell lines. These findings highlight the importanceof considering the specific bacterial strain used in RGO productionas it can influence the toxicity and cellular response of the resultingRGO. The toxicity and cellular response to the final RGO can be affectedby the particular bacterial strain that is employed to produce it. This information will help to ensure that RGO is used safely in avariety of applications, including tissue engineering, drug deliverysystems, and biosensors, where comprehension of its toxicity profileis essential.
Production Sericin/Poly(Vinyl Alcohol) Blend Membranes Containing One-Step Synthesized Silver Nanoparticles by UV Radiation for Obtaining Versatile Antibacterial Materials
(Wiley-V C H Verlag Gmbh, 2024) Temel, Aleyna; Doğan, Hatice Nuran; Yıldız, Emine; Yanık, Gizem; Gök, Zehra Gün
In this study, silver nanoparticles (AgNPs) were in-situ synthesized in silk sericin/poly(vinyl alcohol) (SS/PVA) mixtures by an easy one-step synthesis method with the presence of ultraviolet (UV) radiation. Then, the SS/PVA composite membranes containing AgNPs were obtained by solvent casting method. The chemical structures of the membranes were investigated by fourier-transform infrared spectroscopy (FTIR) and results showed that the membranes were a mixture of silk sericin and PVA. The morphological features of the membranes were investigated by field emission scanning electron microscopy (FE-SEM) and it was seen that AgNPs containing membranes have heterogeneous structures. Energy dispersive spectroscopy (EDS) analysis revealed that the membranes contain carbon, oxygen, nitrogen, sulfur and silver. X-ray diffractometer (XRD) and thermogravimetric (TGA) analyses also proved the presence of AgNPs in the structure of membranes. The antibacterial activities of membranes containing AgNPs were investigated on Staphylococcus aureus and Escherichia coli bacteria with disk diffusion test and liquid culture medium incubation. It was found that SS/PVA membranes containing 5 and 10 mM AgNPs have quite high antibacterial activity on both types of bacteria. The functional SS/PVA membranes have capacity to be used in biomedical applications such as wound care materials. In this work, silver nanoparticles (AgNPs) are synthesized in-situ with UV light within silk sericin/poly(vinyl alcohol) (SS/PVA) polymer mixture and SS/PVA membranes containing AgNPs are obtained with solvent casting method. Various physical, chemical and morphological properties of membranes are examined. The antibacterial activity of the membranes is investigated on bacteria, and the membranes show high antibacterial activity. image
Production and characterization of hybrid nanofiber wound dressing containing Centella asiatica coated silver nanoparticles by mutual electrospinning method
(Pergamon-Elsevier Science Ltd, 2022) Bozkaya, Ogün; Arat, Esra; Gök, Zehra Gün; Yiğitoğlu, Mustafa; Vargel, İbrahim
The aim of this work is to produce a therapeutic and antimicrobial nanofiber wound dressing material with suitable air permeability, water vapor transmission, water absorption, porosity, thermal and mechanical strength. For this purpose, first of all, Centella asiatica (CA) coated silver nanoparticles (CA-AgNPs) are synthesized with using CA extract as reducing and stabilizing agent. The green synthesized CA-AgNPs are characterized by UV-Vis spectroscopy, transmission electron microscope (TEM), zeta potential and fourier transform infrared (FTIR) spectroscopy measurements. The obtained CA-AgNPs give a single peak in the 420-430 nm range between 200 and 700 nm due to surface plasmon resonance (SPR). The average zeta potential and size of CA-AgNPs is found to be-30.4 mV and 14.8 +/- 7.3 nm, respectively. Then, poly caprolactone (PCL) and polyethylene oxide (PEO) nanofibers composition containing CA-AgNPs is synthesized by mutual electrospinning method. Before electrospinning, the PCL solution (12% w/v in chloroform/methanol (70%/30%, v/v)), PEO solution (3.5%, w/v in water) and PEO solutions containing 1%, 5% and 10% (v:v) of CA-AgNPs are prepared. In electrospinning experiments, to synthesis the PCL/PEO nanofibers containing CA-AgNPs, an electrospinning set-up consisting of two high voltage sources, an aluminum rotary roller collector and two syringe pumps (one with a double syringe and the other with a single syringe) is used. To produce the wound dressing materials, PEO solutions containing CA-AgNPs are placed on the double syringe pump and PCL solution is placed on the single syringe pump. The surface and physico-chemical properties of the produced hybrid nanofibers are characterized by field emission scanning electron microscopy (FESEM), energy dispersion spectrometry (EDS), FTIR, X-ray diffractometer (XRD), Brunauer-Emmett-Teller (BET) surface area and porosity analyzer. Also, the thermal and mechanical properties of the obtained materials are investigated. In addition, the air permeability, water uptake capacity, water contact angle, water vapor transmission, in vitro degradation and silver release behavior of the samples are investigated. The results show that mutual dual-spinneret electrospinning technique combines the features of dissimilar components without corruption. Moreover, the in vitro degradation profile and silver release results show that these nanofibers could be used in wound dressing applications in the long term. With antimicrobial studies, PEO/ PCL nanofibers containing 5% and 10% CA-AgNPs are found to be effective against Staphylococcus aureus, Escherichia coli and Candida albicans. Also, the cytotoxic properties of nanofibers are investigated by MTT (3-[4,5dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide) assay and results show the good biocompatibility for L929 fibroblast cells. Results reveal that CA-AgNPs loaded PCL/PEO hybrid nanofibers materials synthesized in this study has a promising potential for wound healing applications.
Preparation of Poly(vinyl alcohol)/Silk Sericin Blend Membranes with Solvent Casting Method For Effective Removal of Remazol Black B
(Korean Fiber Soc, 2023) Gök, Zehra Gün
In the present work, poly(vinyl alcohol)/silk sericin (PVA/SS) membranes were obtained with an easily procedure and removal of remazol black B (RBB) by the membranes was investigated. To synthesize PVA/SS membranes by solvent casting method, 5% SS solution (g/mL) and 10% PVA solution (g/mL) were mixed one to one ratio by volume, the mixture was transferred to a petri dish and incubated at 25 oC for 24 h. Then, the obtained membranes were incubated at 150 oC for 1 h for physical crosslinking. The obtained membranes were characterized with fourier transformed infrared spectroscopy (FTIR), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and thermogravimetric analysis (TGA). Then, for adsorption experiments, firstly, RBB adsorption capabilities of PVA/SS membranes were tested at pH ranging from 2 to 7. After that, the removal experiments were carried out at different incubation time, initial dye concentration and PVA/SS membrane amount to optimize the conditions for removal of RBB with the PVA/SS membranes. The obtained membranes removed high amount of RBB when the solution pH was 2 and the adsorption of RBB to the membranes reached equilibrium within 10 h. The maximum RBB adsorption ability of the PVA/SS membranes was found to be 15.27 mg/g when the initial RBB amount of the solution was 200 mg/L. These results show that PVA/SS membranes, which can be easily synthesized for large applications, have the capacity to be used to remove negatively charged pollutants such as RBB from liquid solutions.
Amino acid surface modified bioglass: A candidate biomaterial for bone tissue engineering1
(Wiley, 2024) Özkabadayı, Yasin; Türk, Mustafa; Kumandaş, Ali; Karahan, Siyami
Bioglasses are solid materials consisted of sodium oxide, calcium oxide, silicon dioxide and phosphorus in various proportions and have used in bone tissue engineering. There have been ongoing efforts to improve the surface properties of bioglasses to increase biocompatibility and performance. The aim of the present study is to modify the bioglass surface with an amino acid mixture consisting of arginine, aspartic acid, phenylalanine, cysteine, histidine and lysine, to characterize the surface, and to evaluate the performance and biocompatibility in vitro and in vivo. The untreated bioglass, bioglass kept in simulated body fluid (SBF), and modified bioglass were used in further evaluation. After confirmation of the surface modification with FT-IR analyses and SEM analyses, MC3T3-E1 preosteoblasts adhesion on the surface was also revealed by SEM. The modified bioglass had significantly higher ALP activity in colorimetric measurement, rate of calcium accumulations in Alizarin red s staining, lower rate of cell death in Annexin-V/PI staining to determine apoptosis and necrosis. Having higher cell viability rate in MTT test and absence of genotoxicity in micronucleus test (OECD 487), the modified bioglass was further confirmed for biocompatibility in vitro. The results of the rat tibial defect model revealed that the all bioglass treatments had a significantly better bone healing score compared to the untreated negative control. However, the modified bioglass exhibited significantly better bone healing efforts especially during the first and the second months compared to the other bioglass treatment treatments. As a result, the amino acid surface modification of bioglasses improves the surface biocompatibility and osteogenic performance that makes the amino acid modified bioglass a better candidate for bone tissue engineering. Research Highlights Bioglass surface modification with amino acids contributes to bioglass-tissue interaction with an improved cell attachment. Modified bioglass increases in vitro Alp activity and calcium accumulation, and also positively affects cell behavior by supporting cell adaptation. Bioglass exerts osteogenic potential in vivo especially during early bone healing.
A detailed study on multifaceted bioactivities of the extracts and isolated compounds from truffle Reddellomyces parvulosporus
(Wiley, 2022) Çayan, Fatih; Tel-Çayan, Gülşen; Deveci, Ebru; Duru, Mehmet Emin; Türk, Mustafa
Mushrooms and truffles are attracting attention as a new generation of biotherapeutics. In the current study, isolation, phenolic and organic acid composition, and antioxidant, cytotoxic, anticholinesterase activities of truffle Reddellomyces parvulosporus were examined. Four known compounds (brassicasterol (1), ergosterol peroxide (2), fumaric acid (3) and mannitol (4)) were isolated with the combination of chromatographic techniques. Fumaric acid (54.74 +/- 0.85 mu g g(-1)) was found as the major compound by HPLC-DAD. All isolated compounds were bioassayed for antioxidant, cytotoxic, anticholinesterase, anti-tyrosinase, anti-urease, anti-alpha-glucosidase and anti-alpha-amylase activities. Compound 1 indicated notable cytotoxic activity on MCF-7 (IC50: 38.08 +/- 0.75 mu g mL(-1)) and compound 3 on H1299 (IC50: 62.37 +/- 0.75 mu g mL(-1)). Also, compounds 1 (84.55 +/- 1.14%) and 2 (84.90 +/- 0.10%) showed higher anti-urease activity than thiourea (78.57 +/- 0.22%), while compound 2 (66.31 +/- 0.08%) displayed near-standard anti-BChE activity. Also, being the first to emphasise the potential of R. parvulosporus as a natural food additive, this study evidenced its medicinal importance by revealing bioactive compounds and properties.
The apoptotic and proliferative effects of tulathromycin and gamithromycin on bovine tracheal epithelial cell culture
(Tubitak Scientific & Technological Research Council Turkey, 2022) Şahin, Yaşar; Yıldırım, Ebru; Yurdakök Dikmen, Begüm; Türk, Mustafa
Gamithromycin and tulathromycin are commonly used in the treatment of bovine respiratory bacterial diseases. The current work was undertaken to establish the apoptotic, necrotic, and cytotoxic effects of these antibiotics in the target animal. Cells with apoptosis and necrosis were determined by dual staining method, cytotoxic effects were determined by MTT assay, cell proliferative effects were examined by XCelligence real-time cell analysis system (RTCA-SP). The comparison between gamithromycin and tulathromycin concentrations on tracheal cells in terms of % cell viability was found to be significantly different. While the cell viability percentage of gamithromycin was higher at 150 mu g/mL, 180 mu g/mL, and 240 mu g/mL than tulathromycin, and at 2 mu g/mL, 4 mu g/mL, 10 mu g/mL, 20 mu g/mL, and 50 mu g/mL concentrations tulathromycin cell viability was higher than gamithromycin (p < 0.05). When the staining method data were evaluated, the difference between the results of % apoptotic index at 20 mu g/mL concentration was significant and it was found that gamithromycin had more apoptotic effect than tulathromycin (p < 0.05). It was seen that tulathromycin and gamithromycin applied on tracheal epithelial cells at concentrations of 2 and 10 mu g/mL increased the viability depending on time. The increase in epithelial cell proliferation of gamithromycin and tulathromycin due to time shows that these antibiotics can maintain longterm prophylactic treatment against diseases.
Investigation of the biocompatibility and in vivo wound healing effect of Cotinus coggygria extracts
(Ankara Univ, 2024) Bozkaya, Esra; Türk, Mustafa; Ekici, Hüsamettin; Karahan, Siyami
Cotinus coggygria is widely recognized its antiseptic, anti-inflammatory, antimicrobial, antihemorrhagic, and wound-healing properties. In this, aimed to evaluate the phenolic contents, cytotoxicity/proliferation, hemolytic, antimicrobial, genotoxic, apoptotic, necrotic activities, and in vivo wound healing effects of C. coggygria, , a plant species known to have beneficial effects on wound healing. TOF-LC/MS analyzes revealed that the methanol extract of C. coggygria leaves contained flavonoids and phenolic compounds such as gallic acid (18.5 mg/kg), catechin (4.6 mg/kg), protocatesic acid (0.6 mg/kg), vanillic acid (8.4 mg/kg), ellagic acid (0.1 mg/kg), rosmarinic acid (0.1 mg/kg), quercetin (15 ppb) and C. coggygria stems contained such as gallic acid (24.6 mg/kg), catechin (155.1 mg/kg), chlorogenic acid (1.9 mg/kg), 4hydroxybenzoic acid (383.3 mg/kg), rutin (2.5 mg/kg), ellagic acid (15.1 mg/kg), apigenin 7-glycoside (10.5 mg/kg), rosmarinic acid (0,4 mg/kg), quercetin (15.2 mg/kg), naringenin (279.1 mg/kg). Consequently, C. coggyria has a positive effect on wound healing with antibacterial properties, particularly against E. coli, and without cytotoxic, genotoxic, or hemolytic effects at test concentrations. In the in vivo burn model, wounds treated with leaf and stem extracts healed faster than the control group. Thus, C. coggygria is an effective plant for wound healing with antibacterial properties, particularly against E. coli, and without cytotoxic, genotoxic, and hemolytic effects.
Effects of functional poly(ethylene terephthalate) nanofibers modified with sericin-capped silver nanoparticles on histopathological changes in parenchymal organs and oxidative stress in a rat burn wound model
(Ankara Univ, 2023) Şahin, Yaşar; Gün Gök, Zehra; Alçığır, Mehmet Eray; Çınar, Miyas
In this study, it was aimed to investigate the effect of a poly(ethylene terephthalate)-g-poly(hydroxyethyl methacrylate) (PET-g-HEMA) nanofiber wound dressing modified with sericin-coated silver nanoparticles (S-AgNPs) on internal organs, oxidative stress, and biochemical parameters. To establish a burn model, the backs of anesthetized rats were shaved and then third-degree burns were created with a round-bottomed stainless steel rod 2 cm in diameter kept in 100 degrees C water for 20 seconds. The wounds of the negative control group (G1) were covered with standard bandages; the wounds of the positive control group (G2) were covered with silvercel, used as burn wound material; and the wounds of the experimental group (G3) were covered with PET-based dressing material. Histopathological changes in organs (liver, kidneys, heart, pancreas, lungs), total oxidant status (TOS), total antioxidant status (TAS), nitric oxide (NO), and biochemical parameters (serum aspartate aminotransferase [AST], alanine aminotransferase [ALT], gamma glutamyl transpeptidase [GGT], creatine kinase, lactate dehydrogenase [LDH], total protein, albumin, globulin, urea) were examined. Compared with the G1 group, plasma AST, ALT, and GGT levels were found to be significantly decreased in G2 and G3 (P<0.001). Plasma TAS was found to be significantly increased in G2 and G3 compared to G1 (P<0.05). Compared to the G1 group, degenerative and necrotic changes in the liver, kidneys, and pancreas were found to be significantly reduced in G2 and G3 (P<0.05). In conclusion, this work demonstrates that the synthesized PET-based wound dressing material has the capacity to be used commercially.
Evaluation of photochemically cross-linked collagen/gold nanoparticle composites as potential skin tissue scaffolds
(Tubitak Scientific & Technological Research Council Turkey, 2023) Yelkuvan, Evrim Meriç; Erdemli, Özge; Yılmaz, Bengi; Aktürk, Ömer
Collagen type I is the main structural unit in skin tissue and is therefore used preferentially in skin tissue scaffolds. However, collagen-based 3D scaffolds have weak aqueous stability and degradation profiles in their uncross-linked states and chemical cross -linking reagents arise toxicity concerns, which generally restrict the spectrum of their biomedical applicability. Here, the research goal is to photochemically cross-link collagen type I with rose bengal (RB) when subjected to green laser light and to investigate the effect of silk sericin-capped gold nanoparticles (S-AuNP) when incorporated into scaffolds on the cross-linking process and thus on the scaffold properties. All the collagen scaffolds, that is plain collagen (C), collagen/S-AuNP (C-Au), cross-linked collagen (C-RBL), and cross-linked collagen/S-AuNP (C-AuRBL) were characterized for their potential as skin tissue scaffolds. C-AuRBL group had the best thermal stability, resistance to enzymatic degradation, and more uniform pore size distribution. None of the groups had cytotoxicity (cell viability > 70%) regarding the microscopic observations and MTT cell viability assays for L929 fibroblasts. L929 fibroblasts and primary adult human epidermal keratinocytes (HEKa) were also separately seeded on C-AuRBL scaffolds and according to microscopy results, they could support the stimulation of adhesion, morphological changes, and spreading of both cells, thereby encouraging the usage of this fabrication strategy for prospective skin tissue scaffolds.
Investigation of the in vitro antibacterial, cytotoxic and in vivo analgesic effects of silver nanoparticles coated with Centella asiatica plant extract
(Ankara Univ, 2023) Bozkaya, Ogun; Ekici, Hüsamettin; Gün Gök, Zehra; Arat, Esra; Ekici, Seda; Yigitoglu, Mustafa; Vargel, İbrahim
In recent years, researchers have shown an increased interest in using medicinal plants for the synthesis of silver nanoparticles (AgNPs) having various therapeutic properties. Centella asiatica (CA), a medicinal plant, has been used to treat minor burn wounds, psoriasis, and hypertrophic wounds among many other pathological conditions. The current study aimed to synthesize CA coated AgNPs (CA-AgNPs) with appropriate biocompatibility and various therapeutic properties, including antimicrobial and analgesic activities. The synthesized CA-AgNPs were characterized by ultraviolet-visible (UV-Vis) spectroscopy, zeta potential measurements, and fourier transform infrared (FT-IR) spectroscopy. The formation of spherical CA-AgNPs was confirmed by a single surface plasmon resonance (SPR) peak emerging at 420 nm wavelength by UV-Vis. The average hydrodynamic diameter and zeta potential of the particles were found to be 29.5 nm and -24.5 mV, respectively. The FT-IR analyses showed that the AgNPs were coated and stabilized by bioactive compounds from the CA extract. MTT cytotoxicity assay revealed that CA-AgNPs at <= 1 mM concentrations exhibited biocompatibility for L929 fibroblast cells. The antimicrobial activity of CA-AgNPs was confirmed by significant inhibition of Staphylococcus aureus and Escherichia coli. In addition, the analgesic effect of CA-AgNPs was investigated for the first time in the literature by tail-flick and hot plate methods, and statistically significant results were obtained for both methods. Taken together, these results suggest that CA-AgNPs can be used as an effective antibacterial and analgesic agent in a variety of biomedical applications, including coating wound dressings.

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