PubMed İndeksli Yayınlar Koleksiyonu / PubMed Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7645
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Article Citation - WoS: 61Citation - Scopus: 64Electrospun Gelma Fibers and P(hema) Matrix Composite for Corneal Tissue Engineering(Elsevier Ltd., 2021) Arıca, Tuğçe A.; Güzelgülgen, Meltem; Yıldız, Ahu Arslan; Demir, Mustafa MuammerThe development of biocompatible and transparent three-dimensional materials is desirable for corneal tissue engineering. Inspired from the cornea structure, gelatin methacryloyl-poly(2-hydroxymethyl methacrylate) (GelMA-p(HEMA)) composite hydrogel was fabricated. GelMA fibers were produced via electrospinning and covered with a thin layer of p(HEMA) in the presence of N,N?-methylenebisacrylamide (MBA) as cross-linker by drop-casting. The structure of resulting GelMA-p(HEMA) composite was characterized by spectrophotometry, microscopy, and swelling studies. Biocompatibility and biological properties of the both p(HEMA) and GelMA-p(HEMA) composite have been investigated by 3D cell culture, red blood cell hemolysis, and protein adsorption studies (i.e., human serum albumin, human immunoglobulin and egg white lysozyme). The optical transmittance of the GelMA-p(HEMA) composite was found to be approximately 70% at 550 nm. The GelMA-p(HEMA) composite was biocompatible with tear fluid proteins and convenient for cell adhesion and growth. Thus, as prepared hydrogel composite may find extensive applications in future for the development of corneal tissue engineering as well as preparation of stroma of the corneal material. © 2020 Elsevier B.V.Article Citation - WoS: 8Citation - Scopus: 7Engineered Silica Nanoparticles Are Biologically Safe Vehicles To Deliver Drugs or Genes To Liver Cells(Elsevier Ltd., 2021) Tüncel, Özge; Kahraman, Erkan; Bağcı, Gülsün; Atabey, Neşe; Özçelik, SerdarEngineered silica nanoparticles (SiNP) are emerging materials for medical applications. Evaluating biological responses of specific cells treated with engineered silica nanoparticles is however essential. We synthesized and characterized the physicochemical properties of silica nanoparticles with two different sizes of 10 and 100 nm (10SiNP and 100SiNP) dispersed in cell culture medium. HuH-7, an epithelial-like human hepatoblastoma cell line and SK-HEP-1, a liver sinusoidal endothelial cell line (LSEC) are employed to evaluate their biological responses for the SiNP treatment. Primary human lymphocytes are used to assess genotoxicity recommended by OECD guidelines while erythrocytes are used to assess hemolytic activity. The engineered silica nanoparticles are not able to produce radical species, to alter the mitochondrial membrane potential, and induce any adverse effects on cell proliferation. The colony formation ability of HuH-7 hepatoblastoma cells was not affected following the SiNP treatment. Furthermore, SiNPs do not induce hemolysis of red blood cells and are not genotoxic. These findings suggest that SiNPs regardless of the size, amount, and incubation time are biologically safe vehicles to deliver drugs or genes to the liver. © 2020 Elsevier B.V.Article Citation - WoS: 25Citation - Scopus: 30Prediction of Chemical Parameters and Authentication of Various Cold Pressed Oils With Fluorescence and Mid-Infrared Spectroscopic Methods(Elsevier Ltd., 2021) Doğruer, Ilgın; Uyar, H. Hilal; Uncu, Oğuz; Özen, BanuIt was aimed to compare the performances of two spectroscopic methods, fluorescence and mid-infrared spectroscopy, in terms of their adulteration detection and estimation of several chemical properties for various cold pressed seed oils. Spectroscopic profiles, fatty acid, free fatty acid and total phenol contents of pumpkin seed, grape seed, black cumin oil, and sesame seed oils were determined and these oils were mixed with sunflower oil at 1–50% (v/v). Both spectroscopic techniques provided comparable results for determination of adulteration of each oil type and the most successful prediction was obtained for pumpkin seed oil at levels >%1. Combined data set of oils resulted in successful quantification of their free fatty acid value, total phenol and major fatty acids contents with both spectroscopic methods regardless of oil type. Both techniques could be used as reliable, fast and environmentally friendly alternatives in the analyses of different types of seed oils. © 2020 Elsevier LtdArticle Citation - WoS: 19Genotypic Identification of Some Lactic Acid Bacteria by Amplified Fragment Length Polymorphism Analysis and Investigation of Their Potential Usage as Starter Culture Combinations in Beyaz Cheese Manufacture(Elsevier Ltd., 2010) Karahan, A. G.; Kilic, G. Basyigit; Kart, A.; Aloglu, H. Sanlidere; Oner, Z.; Aydemir, S.; Harsa, Hayriye Şebnem; Erkuş, OylumIn this study, 2 different starter culture combinations were prepared for cheesemaking. Starter culture combinations were formed from 8 strains of lactic acid bacteria. They were identified as Lactococcus lactis ssp. lactis (2 strains), Lactobacillus plantarum (5 strains), and Lactobacillus paraplantarum (1 strain) by amplified fragment length polymorphism analysis. The effects of these combinations on the physicochemical and microbiological properties of Beyaz cheeses were investigated. These cheeses were compared with Beyaz cheeses that were produced with a commercial starter culture containing Lc. lactis ssp. lactis and Lc. lactis ssp. cremoris as control. All cheeses were ripened in brine at 4 degrees C for 90 d. Dry matter, fat in dry matter, titratable acidity, pH, salt in dry matter, total N, water-soluble N, and ripening index were determined. Sodium dodecyl sulfate-PAGE patterns of cheeses showed that alpha(S)-casein and beta-casein degraded slightly during the ripening period. Lactic acid bacteria, total mesophilic aerobic bacteria, yeast, molds, and coliforms were also counted. All analyses were repeated twice during d 7, 30, 60, and 90. The starter culture combinations were found to be significantly different from the control group in pH, salt content, and lactobacilli, lactococci, and total mesophilic aerobic bacteria counts, whereas the cheeses were similar in fat, dry matter content, and coliform, yeast, and mold counts. The sensory analysis of cheeses indicated that textural properties of control cheeses presented somewhat lower scores than those of the test groups. The panelists preferred the tastes of treatment cheeses, whereas cheeses with starter culture combinations and control cheeses had similar scores for appearance and flavor. These results indicated that both starter culture combinations are suitable for Beyaz cheese production.Article Citation - WoS: 44Hesperidin Promotes Programmed Cell Death by Downregulation of Nongenomic Estrogen Receptor Signalling Pathway in Endometrial Cancer Cells(Elsevier Ltd., 2018) Cincin, Zeynep Birsu; Kıran, Bayram; Baran, Yusuf; Çakmakoğlu, BediaEndometrial carcinoma (EC) is the most common malignant gynecologic tumor in women. EC is thought to be caused by increasing estrogen levels relative to progesterone in the body. Hesperidin (Hsd), a biologically active flavonoid, could be extracted from Citrus species. It has been recently shown that Hsd could exert anticarcinogenic properties in different cancer types. However, the effects of Hsd and its molecular mechanisms on EC remain unclear. In this study, the antiproliferative, apoptotic and genomic effects of Hsd in EC and its underlying mechanisms were identified. We found that Hsd significantly suppressed the proliferation of EC cells in dose and time dependent manner. Mechanistic studies showed that Hsd could contribute apoptosis by inducing externalization of phosphatidyl serine (PS), caspase-3 activity and loss of mitochondrial membrane (MMP). Furthermore, we examined that Hsd could also significantly upregulate the expression of proapoptotic Bax subgroup genes (Bax and Bik) while downregulating the anti-apoptotic protein Bcl-2 in EC cell lines. According to GO enrichment and KEGG pathway analysis of differentially expressed genes in Hsd treated EC cells, we identified that Hsd could promote cell death via downregulation of estrogen receptor I (ESRI) that was directly related to ERK/MAPK pathway. Taken together, our study first showed that Hsd could be an antiestrogenic compound that could modulate nongenomic estrogen receptor signaling through inhibition of EC cell growth. Our findings may provide us a novel growth inhibitory agent for EC treatment after verifying its molecular mechanism with in vivo studies.Article Citation - WoS: 71Citation - Scopus: 76Characterization of Bacterial Cellulose Nanocrystals: Effect of Acid Treatments and Neutralization(Elsevier Ltd., 2021) Arserim-Uçar, Dilhun Keriman; Korel, Figen; Liu, LinShu; Yam, Kit LIn this study, bacterial cellulose nanocrystals (BCNCs) were obtained from bacterial cellulose nanofibers (BCNFs) by controlled hydrolysis of sulfuric and hydrochloric acids. The influence of hydrolysis temperature and acid type with the addition of the post-treatment step was studied. The obtained BCNCs were analyzed based on the structural characterization and the properties of the nanocrystals. The BCNCs crystallinity increased, and the size of nanocrystals decreased with increasing 10 °C hydrolysis temperature for both acid hydrolysis conditions. Hydrolysis conditions with neutralization post-treatment did not alter the thermal stability of nanocrystals, and BCNCs had high thermal stability like raw BCNFs. Elemental analysis results indicated that sulfur content (S %) was very low for sulfuric acid hydrolyzed samples, and X-ray results did not show any sulfate salt peaks. Thermal stable BCNCs with high crystallinity were successfully produced to meet the process requirements in various applications, especially in the food industry.Article Citation - WoS: 54Citation - Scopus: 64Bioactive Fish Scale Incorporated Chitosan Biocomposite Scaffolds for Bone Tissue Engineering(Elsevier Ltd., 2019) Kara, Aylin; Tamburacı, Sedef; Tıhmınlıoğlu, Funda; Havıtçıoğlu, HasanRecently, biologically active natural macromolecules have come into prominence to be used as potential materials in scaffold design due to their unique characteristics which can mimic the human tissue structure with their physical and chemical similarity. Among them, fish scale (FS) is a biologically active material with its structural similarity to bone tissue due to including type I collagen and hydroxyapatite and also have distinctive collagen arrangement. In the present study, it is aimed to design a novel composite scaffold with FS incorporation into chitosan (CH) matrix for bone tissue regeneration. Therefore, two biological macromolecules, fish scale and chitosan, were combined to produce bio-composite scaffold. First, FS were decellularized with the chemical method and disrupted physically as microparticles (100 in), followed by dispersal in CH with ultrasonic homogenisation, CH/FS scaffolds were fabricated by lyophilization technique. Scaffolds were characterized physically, chemically, mechanically, and morphologically. SEM and porosity results showed that CH/FS scaffolds have uniform pore structure showing high porosity. Mechanical properties and degradation rate are enhanced with increasing FS content. In vitro cytotoxicity, proliferation and osteogenic activity of the scaffolds were evaluated with SaOS-2 cell line. CH/FS scaffolds did not show any cytotoxicity effect and the cells were gradually proliferated during culture period. Cell viability results showed that, FS microparticles had a proliferative effect on SaOS-2 cells when compared to control group. ALP activity and biomineralization studies indicated that FS micro particle reinforcement increased osteogenic activity during culture period. As a biological macromolecule with unique characteristics, FS was found as cytocompatible and provided promising effects as reinforcement agents for polymeric scaffolds. In conclusion, fabricated CH/FS bio-composites showed potential for bone tissue engineering applications. (C) 2019 Elsevier B.V. All rights reserved.Article Citation - WoS: 24Citation - Scopus: 26Self-Assembly Behavior of the Keratose Proteins Extracted From Oxidized Ovis Aries Wool Fibers(Elsevier Ltd., 2019) Pakkaner, Efecan; Yalçın, Damla; Uysal, Berk; Top, AybenWater soluble keratose proteins were obtained from an Ovis Aries wool using peracetic acid oxidation. The wool samples and the extracted keratose proteins were characterized by using FTIR, XRD, SEM and TGA techniques. Fractions of alpha-keratose (MW = 43-53 kDa) along with protein species with molecular weights between 23 kDa and 33 kDa were identified in the SDS-PAGE analysis result of the extracted protein mixture. DLS and AFM experiments indicated that self-assembled globular nanoparticles with diameters between 15 nm and 100 nm formed at 5 mg/ml keratose concentration. On the other hand, upon incubation of 10 w % keratose solutions at 37 degrees C and 50 degrees C, interconnected keratose hydrogels with respective storage modulus (G') values of 0.17 +/- 0.03 kPa and 3.7 +/- 0.5 kPa were obtained. It was shown that the keratose hydrogel prepared at 37 degrees C supported L929 mouse fibroblast cell proliferation which suggested that these keratose hydrogels could be promising candidates in soft tissue engineering applications. (C) 2018 Elsevier B.V. All rights reserved.Article Citation - WoS: 15Citation - Scopus: 13Cascade Therapy With Doxorubicin and Survivin-Targeted Tailored Nanoparticles: an Effective Alternative for Sensitization of Cancer Cells To Chemotherapy(Elsevier Ltd., 2019) Dağlıoğlu, Cenk; Kacı, Fatma NecmiyeChemotherapy frequently involves combination treatment protocols to maximize tumor cell killing. Unfortunately these intensive chemotherapeutic regimes, often show disappointing results due to the development of drug resistance and higher nonspecific toxicity on normal tissues. In cancer treatment, it is critically important to minimize toxicity while preserving efficacy. We have previously addressed this issue and proposed a nanoparticle-based combination therapy involving both a molecularly targeted therapy and chemotherapeutic agent for neutralizing antiapoptotic survivin (BIRC5) to potentiate the efficacy of doxorubicin (DOX). Although the particles exhibited strong anticancer effect on the lung carcinoma A549 and the cervical carcinoma HeLa cells, there were lower-level therapeutic outcomes on the colon carcinoma HCT-116, the leukemia Jurkat and the pancreatic carcinoma MIA PaCa-2 cells. Since targeted therapies are one of the key approaches for overcoming drug resistance, tailoring the treatment of cancer cells with distinct characteristics is necessary to improve the therapeutic outcome of cancer therapy and to minimize potential pharmacokinetic interactions of drugs. In the light of this issue, this study examined whether a cascade therapy with low-dose DOX and survivin-targeted tailored nanoparticles is more effective at sensitizing HCT-116, Jurkat and MIA PaCa-2 cancer cells to DOX-chemotherapy than simultaneous combination therapy. The results demonstrated that the sequential therapy with the protocol comprising addition of the nanoparticles after incubation of cells with DOX clearly advanced the therapeutic outcome of related cancer cells, whereas the reverse protocol resulted in a reduction or delay in apoptosis, emphasizing the critical importance of formulating synergistic drug combinations in cancer therapy.Article Citation - WoS: 34Citation - Scopus: 36Biomimetic Hybrid Scaffold Consisting of Co-Electrospun Collagen and Pllcl for 3d Cell Culture(Elsevier Ltd., 2019) Türker, Esra; Yıldız, Ümit Hakan; Arslan Yıldız, AhuElectrospun collagen is commonly used as a scaffold in tissue engineering applications since it mimics the content and morphology of native extracellular matrix (ECM) well. This report describes "toxic solvent free" fabrication of electrospun hybrid scaffold consisting of Collagen (Col) and Poly(L-lactide-co-epsilon-caprolactone) (PLLCL) for three-dimensional (3D) cell culture. Biomimetic hybrid scaffold was fabricated via co-spinning approach where simultaneous electrospinning of PLLCL and Collagen was mediated by polymer sacrificing agent Polyvinylpyrrolidone (PVP). Acidified aqueous solution of PVP was used to solubilize collagen without using toxic solvents for electrospinning, and then PVP was readily removed by rinsing in water. Mechanical characterizations, protein adsorption, as well as biodegradation analysis have been conducted to investigate feasibility of biomimetic hybrid scaffold for 3D cell culture applications. Electrospun biomimetic hybrid scaffold, which has 3D-network structure with 300-450 nm fiber diameters, was found to be maximizing cell adhesion through assisting NIH 3T3 mouse fibroblast cells. 3D cell culture studies confirmed that presence of collagen in biomimetic hybrid scaffold have created a major impact on cell proliferation compared to conventional 2D systems on long-term, also cell viability increased with the increasing amount of collagen. (c) 2019 Elsevier B.V. All rights reserved.