İlhan, Elif | Karahaliloğlu, Zeynep | Kılıçay, Ebru | Hazer, Baki | Denkbaş, Emir Baki

Article | 2019 | Materials Technology

Postoperative infection in orthopaedic and trauma surgery is one of the most feared complications. Recently, the high prevalence of multidrug-resistant bacteria has made the antibiotic treatment ineffective; thus novel non-antibiotic alternative approaches to this problem are urgently needed. Based on these expectations, in this work, in order to enhance the cytocompatibility and antibacterial performances of poly (methyl methacrylate (PMMA) and beta-tricalcium phosphate (ß-TCP) bone cements were impregnated with polystyrene (PS)-g-soybean oil graft copolymer containing AgNPs (PS-Agsbox), and we assessed the antimicrobial activity o . . .f the fabricated bone cements against Staphylococcus aureus and Escherichia coli. Nanoparticles at concentration of 1.25% (5 ß-TCP) w/w in ß-TCP bone cements were able to inhibit pathogens growth, while a concentration of 3.75% (15PMMA) was needed for PMMA bone cement. Therefore, the impregnated bone cements with PS-AgsboxNPs may be further explored as an alternative antimicrobial therapy for the treatment of infected bone defects. © 2019, © 2019 Informa UK Limited, trading as Taylor & Francis Group Daha fazlası Daha az

Adamski, Zbigniew | Marciniak, Pawel | Ziemnicki, Kazimierz | Büyükgüzel, Ender | Erdem, Meltem | Büyükgüzel, Kemal | Ventrella, Emanuela

Article | 2014 | ARCHIVES OF INSECT BIOCHEMISTRY AND PHYSIOLOGY87 ( 1 ) , pp.26 - 39

Plants synthesize a broad range of secondary metabolites that act as natural defenses against plant pathogens and herbivores. Among these, potato plants produce glycoalkaloids (GAs). In this study, we analyzed the effects of the dried extract of fresh potato leaves (EPL) on the biological parameters of the lepidopteran, Galleria mellonella (L.) and compared its activity to one of the main EPL components, the GA alpha-solanine. Wax moth larvae were reared from first instar on a diet supplemented with three concentrations of EPL or alpha-solanine. Both EPL and alpha-solanine affected survivorship, fecundity, and fertility of G. mellon . . .ella to approximately the same extent. We evaluated the effect of EPL and alpha-solanine on oxidative stress in midgut and fat body by measuring malondialdehyde (MDA) and protein carbonyl (PCO) contents, both biomarkers of oxidative damage. We evaluated glutathione S-transferase (GST) activity, a detoxifying enzyme acting in prevention of oxidative damage. EPL and alpha-solanine altered MDA and PCO concentrations and GST activity in fat body and midgut. We infer that the influence of EPL on G. mellonella is not enhanced by synergistic effects of the totality of potato leaf components compared to alpha-solanine alone. (C) 2014 Wiley Periodicals, Inc Daha fazlası Daha az

Kılıçay, Ebru | Karahaliloğlu, Zeynep | Alpaslan, Pınar | Hazer, Baki | Denkbaş, Emir Baki

Article | 2017 | JOURNAL OF BIOMATERIALS SCIENCE-POLYMER EDITION28 ( 15 ) , pp.1762 - 1785

Antisense oligonucleotide (ASO)-conjugated--tocopherol succinate (TCS)-loaded-poly(lactic acid)-g-poly(ethylene glycol) nanoparticles (ASO-TCS-PLA-PEG NPs), with the ratio of polymer/TCS of 10:2.5, 10:5, 10:7 (w/w) were prepared for targeting cancer therapy. The amphiphilic PLA, amino terminated PEG graft copolymers were synthesized by ring opening polymerization reaction. Nanoparticles were produced by using double emulsion (w/o/w) solvent evaporation method. ASO-TCS-PLA-PEG NPs demonstrated satisfactory encapsulation and loading efficiency and size distribution. The short-term stability studies were carried out at 4 and 25 degrees . . . C for 30days to assess their mean particle size, polydispersity index and zeta potential. The cellular uptake and extended cytoplasmic retention of the NPs in A549 human lung carcinoma and L929 mouse fibroblast cells were examined by fluorescence and confocal microscopy. In human lung cancer cells, ASO-TCS-PLA-PEG NPs exhibited better cellular internalization, cytotoxicity and apoptotic and necrotic effects compared to healthy cell line, L929. These findings showed that ASO-modified nanoparticles could serve as a promising nanocarrier for targeted tumor cells Daha fazlası Daha az

Büyükgüzel, Kemal | Büyükgüzel, Ender | Erdem, Meltem | Küçük, Ceyhun | Atılgan, Utku Can

Proceedings | 2016 | FEBS JOURNAL283 , pp.66 - 66

41st FEBS Congress on Molecular and Systems Biology for a Better Life -- SEP 03-08, 2016 -- Kusadasi, TURKEY WOS: 000383616900195

Büyükgüzel, Ender | Erdem, meltem | Tunaz, Hasan | Küçük, Ceyhun | Atılgan, Utku Can | Stanley, David | Büyükgüzel, Kemal

Article | 2017 | Comparative Biochemistry and Physiology -Part A : Molecular and Integrative Physiology204 , pp.121 - 128

We posed the hypothesis that inhibition of eicosanoid biosynthesis leads to increased lipid peroxidation in insects. Here we report that rearing the greater wax moth, Galleria mellonella, on media supplemented with selected inhibitors of eicosanoid biosynthesis throughout the larval, pupal and adult life led to major alterations in selected oxidative and antioxidative parameters of wax moth and its ectoparasitoid, Bracon hebetor. The highest dietary dexamethasone (Dex), esculetin (Esc) and phenidone (Phe) led to increased malondialdehyde (MDA) levels and to elevated catalase (CAT) and glutathione-S-transferase (GST) activities in al . . .l developmental stages of host larvae. Dietary Phe resulted in increased MDA levels, and CAT activity in G. mellonella adults by about 4-fold and about 2-fold, respectively. The Phe effect on GST activity in all stages of the wax moth was expressed in a dose-dependent manner, increased to 140 nmol/mg protein/min in larvae. MDA levels were increased by over 30-fold in adult wasps reared on Dex- and Esc-treated hosts. CAT and GST activities were increased in adult parasitoids reared on Esc-and Phe-treated hosts. GST activity of Dex-treated parasitoid larvae increased from about 4 to over 30 nmol/mg protein/min. Dietary Phe led to increased GST activity, by about 25-fold, in adult wasps. These data indicate that chronic inhibition of eicosanoid biosynthesis leads to increased oxidative stress, strongly supporting our hypothesis. The significance of this work lies in understanding the roles of eicosanoids in insect biology. Aside from other well-known eicosanoids actions, we propose that eicosanoids mediate reductions in oxidative stress. © 2016 Elsevier Inc Daha fazlası Daha az

Erdem, Meltem | Küçük, Ceyhun | Büyükgüzel, Ender | Büyükgüzel, Kemal

Article | 2016 | Archives of Insect Biochemistry and Physiology93 ( 4 ) , pp.202 - 209

Gemifloxacin mesylate (GEM) is a synthetic, fourth-generation fluoroquinolone antibacterial antibiotic that has a broad spectrum of activity against bacteria. GEM inhibits DNA synthesis by inhibiting DNA gyrase and topoisomerase IV activities. Recent research into insect nutrition and mass-rearing programs, in which antibiotics are incorporated into the culture media to maintain diet quality, raised a question of whether clinical antibiotics influence the health or biological performance of the insects that ingest these compounds. Because some antibiotics are pro-oxidant compounds, we addressed the question with experiments designed . . . to assess the effects of GEM (mesylate salt) on oxidative stress indicators, using Galleria mellonella larvae. The insects were reared from first-instar larvae to adulthood on artificial diets amended with GEM at 0.001, 0.01, 0.1, or 1.0%. Feeding on the 1% diets led to significantly increased hemolymph contents of the lipid peroxidation product, malondialdehyde and protein oxidation products, protein carbonyl. All GEM concentrations led to increased hemolymph glutathione S-transferase activity. We inferred that although it was not directly lethal to G. mellonella larvae, dietary exposure to GEM exerts measurable oxidative damage, possibly on insects generally. Long-term, multigenerational effects remain unknown. © 2016 Wiley Periodicals, Inc Daha fazlası Daha az

Ventrella, Emanuela | Adamski, Zbigniew | Chudzinska, Ewa | Miadowicz-Kobielska, Mariola | Marciniak, Pavel | Büyükgüzel, Ender | Büyükgüzel, Kemal | Erdem, Meltem | Falabella, Patrizia | Scrano, Laura | Bufo, Sabino Aurelio

Article | 2016 | PLoS ONE11 ( 5 ) , pp.202 - 209

Glycoalkaloids are secondary metabolites commonly found in Solanaceae plants. They have anti-bacterial, anti-fungal and insecticidal activities. In the present study we examine the effects of potato and tomato leaf extracts and their main components, the glycoalkaloids ?-solanine, ?-chaconine and ?-tomatine, on development and reproduction of Drosophila melanogaster wild-type flies at different stages. Parental generation was exposed to five different concentrations of tested substances. The effects were examined also on the next, non-exposed generation. In the first (exposed) generation, addition of each extract reduced the number . . .of organisms reaching the pupal and imaginal stages. Parent insects exposed to extracts and metabolites individually applied showed faster development. However, the effect was weaker in case of single metabolites than in case of exposure to extracts. An increase of developmental rate was also observed in the next, non-exposed generation. The imagoes of both generations exposed to extracts and pure metabolites showed some anomalies in body size and malformations, such as deformed wings and abdomens, smaller black abdominal zone. Our results further support the current idea that Solanaceae can be an impressive source of molecules, which could efficaciously be used in crop protection, as natural extract or in formulation of single pure metabolites in sustainable agriculture. © 2016 Ventrella et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited Daha fazlası Daha az

Kılıçay, Ebru | Erdal, Ebru | Hazer, Baki | Türk, Mustafa | Denkbaş, Emir Baki

Article | 2016 | Artificial Cells, Nanomedicine and Biotechnology44 ( 8 ) , pp.1938 - 1948

Amphiphilic poly(3-hydroxylalkanoate) (PHA) copolymers find interesting applications in drug delivery. The aim of this study was to prepare nucleic acid adsorbed on (PHB-b-PEG-NH2) nanoparticle platform for gene delivery. For this purpose, PHB-b-PEG-NH2 block copolymers were synthesized via transesterification reactions. The copolymers obtained were characterized by Proton Nuclear Magnetic Resonance (1H-NMR), Fourier Transform Infrared Spectrometer (FTIR), Thermogravimetric Analysis (TGA) and Differential Scanning Calorimetry (DSC) techniques. The cytotoxic, apoptotic and necrotic effects of these nanoparticles in the MDA 231 human . . .breast cancer cell, the A549 human lung cancer cell and the L929 fibroblast cell lines were also investigated. © 2015 Taylor & Francis Daha fazlası Daha az

Kılıçay, Ebru | Karahaliloğlu, Zeynep | Hazer, Baki | Tekin, İshak Özel | Denkbaş, Emir Baki

Article | 2016 | Journal of Microencapsulation33 ( 3 ) , pp.274 - 285

The aim of this study was to evaluate therapeutic potential of curcumin-loaded poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) PHBHHx nanoparticles (CUR-NPs) and concanavaline A conjugated curcumin-loaded NPs (ConA-CUR-NPs) for breast cancer treatment. The size and zeta potential of prepared NPs were about 228 ± 5 nm and -23.3 mV, respectively. The entrapment efficiencies of polymer/drug weight ratios, 1.25CUR-NPs, 2.5CUR-NPs, 5CUR-NPs, ConA-1.25CUR-NPs, ConA-2.5CUR-NPs and ConA-5CUR-NPs were found to be ?68, 55, 45, 70, 60 and 51%, respectively. Optimized NPs formulations in the freeze-dried form were assessed with their short-term s . . .tability for 30 days of storage at 4 °C and 25 °C. Anticancer activity of ConA-CUR-NPs was proved by MTT assay and reconfirmed by double staining and flow cytometry results. The anticancer activity of ConA-CUR-NPs was measured in human breast cancer cells (MDA-MB 231) in vitro, and the results revealed that the ConA-CUR-NPs had better tumor cells decline activity. © 2016 Informa UK Limited, trading as Taylor & Francis Group Daha fazlası Daha az

Hız, Pınar | Erdem, Meltem | Büyükgüzel, Ender | Büyükgüzel, Kemal

Article | 2016 | KAFKAS UNIVERSITESI VETERINER FAKULTESI DERGISI22 ( 5 ) , pp.777 - 784

Greater wax moth, Galleria mellonella L. is most commonly used as model insects for studying insecticidal efficiency of chemicals as well as it has been known as an alternative model to mamalian model for studying microbial infections and clinical drugs. The effects of a fluoroquinolone antibacterial agent, gemifloxacin, on sex ratio, male and female adult longevity, fecundity and hatchability of this insect were investigated by rearing the first instar larvae on artificial diets in the laboratory condition. The insect was reared from first-instar larvae to adult stage on an artificial diets containing gemifloxacin at 0.001, 0.01, 0 . . ..1 or 1.0%. Gemifloxacin did not affect male and female sex ratio and adult longevity while it significantly decreased egg number. Fecundity and hatchability were significantly and inversely decreased by increasing gemifloxacin concentrations. The females reared from control diet produced 134.46 per day, whereas high concentrations of gemifloxacin decreased the egg number to 26.75 and 53.5. Hatchability was also significantly decreased by 0.01% and above concentrations of gemifloxacin whereas, the highest concentration of antibiotic lowered the hatchability to 53.71%. This study indicated sublethal effects of gemifloxacin are likely to have a significant impact on adult biological traits and these effects show concentration-dependent variation in biological traits of the insect Daha fazlası Daha az

Erdem, Meltem | Büyükgüzel, Ender | Büyükgüzel, Kemal

Article | 2016 | Journal of Entomological Science51 ( 4 ) , pp.305 - 313

he fruit fly Drosophila melanogaster (Meigen) (Diptera: Drosophilidae) is often used in various biological, molecular, and toxicological studies. Sodium tetraborate, a boron compound, was added to the artificial diet of developing D. melanogaster to determine its effects on adult longevity and fecundity. Insects reared from first instars to adults on diets containing 10, 30, 150, 300, or 400 mg/liter sodium tetraborate showed that the highest concentration (400 mg/liter) significantly reduced female longevity (31.65 6 4.02 [mean 6 SD] d for the controls versus 1.87 6 0.30 d for 400 mg/liter) and male longevity (32.80 6 1.96 d for co . . .ntrols versus 3.57 6 0.42 d for 400 mg/liter). Females from the control diet produced 9.46 6 0.57 (mean 6 SD) eggs per female, whereas those fed on a diet containing 300 mg/liter produced only 1.92 6 0.30 eggs per females. These results expand our knowledge of the impact of sodium tetraborate on various insects and indicate that boron compounds should be further investigated to ascertain their potential as an alternative control tactic for pest insects Daha fazlası Daha az

Erdem, Meltem | Büyükgüzel, Ender

Article | 2015 | Archives of Insect Biochemistry and Physiology89 ( 4 ) , pp.193 - 203

The effects of a dietary plant allelochemical, xanthotoxin (XA), on survivorship, development, male and female adult longevity, fecundity, and hatchability of the greater wax moth Galleria mellonella L. were investigated. Oxidative stress indicators, the lipid peroxidation product, malondialdehyde (MDA), and protein oxidation products, protein carbonyl (PCO) contents, and activities of a detoxification enzyme glutathione S-transferase (GST) activity were determined in wax moth adults. The insect was reared from first-instar larvae on an artificial diets containing XA at 0.001, 0.005, or 0.1% to adult stage in laboratory conditions. . . .Relative to the controls, the diets containing XA concentrations led to decreased survivorship in seventh instar, pupal, and adult stages. Compared to control diet (77.7%), the highest dietary XA concentration decreased survivorship to adulthood to 11.0%. The highest XA concentration (0.1%) reduced female longevity from 10.4 to 5.7 days and decreased egg numbers from 95.0 to 33.5 and hatchability from 82.7 to 35.6%. The lowest XA concentration (0.001%) led to about a sixfold increase in MDA content. XA at high concentrations (0.005 and 0.1%) increased MDA (by threefold) and protein carbonyl (by twofold) contents decreased GST activity. The highest dietary XA concentration decreased GST activity from 0.28 ± 0.025 to 0.16 ± 0.005 µmol/mg protein/min. We infer from these findings that XA-induced oxidative stress led to decreased biological fitness. © 2015 Wiley Periodicals, Inc Daha fazlası Daha az