Person: OKTAR, FAİK NÜZHET
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OKTAR
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FAİK NÜZHET
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Publication Metadata only Preparation and characterization of electrospun polylactic acid/sodium alginate/orange oyster shell composite nanofiber for biomedical application(SPRINGER, 2020) BİLĞİÇ ALKAYA, DİLEK; Cesur, Sumeyye; Oktar, Faik Nuzhet; Ekren, Nazmi; Kilic, Osman; Alkaya, Dilek Bilgic; Seyhan, Serap Ayaz; Ege, Zeynep Ruya; Lin, Chi-Chang; Erdem, Serap; Erdemir, Gokce; Gunduz, OguzhanBone tissue engineering has begun to draw attention in recent years. The interactive combination of biomaterials and cells is part of bone tissue engineering. Sodium alginate (SA) is a biologically compatible, degradable, non-toxic natural polymer accepted by the human body and is widely used in the field of tissue engineering. Polylactic acid (PLA) is another type of biodegradable thermoplastic polyester derived from renewable sources which are used in bone tissue engineering and biomedical owing to its biocompatibility and biodegradability. Hydroxyapatite (HA) and tricalcium phosphate (TCP) derived from natural sources such as marine species and bovine bone are biocompatible and non-toxic biomaterials which are used to reconstruct many parts of the skeleton. In this study, PLA, SA with different compositions, and nanofibers obtained by adding orange spiny oyster shell powders (Spondylus barbatus) to them by using electrospining technique. Cell culture study, scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), and physical analysis such as density, electrical conductivity, surface tension, viscosity measurement, and tensile strength measurement tests were carried out after the production process. Produced nanofibers showed smooth and beadless surface. The average diameters and distributions decreased with the addition of optimum PLA and TCP amount. The tensile strength of nanofibers was enhanced with the additional SA and TCP. The produced nanofibers are compatible with human bone tissue, which are not cytotoxic, and in addition, a high cell efficiency of SaOS-2 cells on the nanofibers was observed with SEM images.Publication Metadata only Fabrication and characterization of pla/sa/ha composite nanofiber by electrospinning for bone tissue engineering applications(2018-07-18) CESUR, SÜMEYYE; EKREN, NAZMİ; KILIÇ, OSMAN; OKTAR, FAİK NÜZHET; BİLĞİÇ ALKAYA, DİLEK; AYAZ SEYHAN, SERAP; GÜNDÜZ, OĞUZHAN; Cesur S., Ekren N., Kılıç O., Oktar F. N., Bilğiç Alkaya D., Ayaz Seyhan S., Ege Z. R., Gündüz O.Publication Metadata only Synthesis and characterization of antibacterial drug loaded beta-tricalcium phosphate powders for bone engineering applications(SPRINGER, 2020) OKTAR, FAİK NÜZHET; Topsakal, Aysenur; Ekren, Nazmi; Kilic, Osman; Oktar, Faik N.; Mahirogullari, Mahir; Ozkan, Ozan; Sasmazel, Hilal Turkoglu; Turk, Mustafa; Bogdan, Iuliana M.; Stan, George E.; Gunduz, OguzhanPowders of beta-tricalcium phosphate [beta-TCP, beta-Ca-3(PO4)(2)] and composite powders of beta-TCP and polyvinyl alcohol (PVA) were synthesized by using wet precipitation methods. First, the conditions for the preparation of single phase beta-TCP have been delineated. In the co-precipitation procedure, calcium nitrate and diammonium hydrogen phosphate were used as calcium and phosphorous precursors, respectively. The pH of the system was varied in the range 7-11 by adding designed amounts of ammonia solution. The filtered cakes were desiccated at 80 degrees C and subsequently calcined at different temperatures in the range between 700-1100 degrees C. Later on, rifampicin form II was used to produce drug-loaded beta-TCP and PVA/beta-TCP powders. All the synthesized materials have been characterized from morphological (by scanning electron microscopy) and structural-chemical (by X-ray diffraction and Fourier transform infrared spectroscopy) point of view. The drug loading capacity of the selected pure beta-TCP powder has been assessed. The biological performance (cytocompatibility in fibroblast cell culture and antibacterial efficacy against Escherichia coli and Staphylococcus aureus) has been tested with promising results. Application perspectives of the designed drug-bioceramic-polymer blends are advanced and discussed. [GRAPHICS] .Publication Metadata only Oyun Değiştiren Güç: Yapay Zekâ.(Beta Basım Yayım Dağıtım, 2020-06-01) AKYURT, NURAN; OKTAR, FAİK NÜZHET; ACAR BÜYÜKPEHLİVAN, GÜLHAN; BUĞDAYCI, ONUR; Akyurt N., Oktar F. N. , Acar Büyükpehlivan G., Buğdaycı O.Publication Metadata only Development of Satureja cuneifolia-loaded sodium alginate/polyethylene glycol scaffolds produced by 3D-printing technology as a diabetic wound dressing material(ELSEVIER, 2020) OKTAR, FAİK NÜZHET; Ilhan, Elif; Cesur, Sumeyye; Guler, Ece; Topal, Fadime; Albayrak, Deniz; Guncu, Mehmet Mucahit; Cam, Muhammet Emin; Taskin, Turgut; Sasmazel, Hilal Turkoglu; Aksu, Burak; Oktar, Faik Nuzhet; Gunduz, OguzhanAcute wounds are a common health problem, with millions of people affected and decreased granulation tissue formation and vascularization, it is also a big challenge for wound care researchers to promote acute wound healing around the globe. This study aims to produce and characterize Satureja cuneifolia plant extract (SC) blended with sodium alginate (SA) /polyethylene glycol (PEG) scaffolds for the potential treatment of diabetic ulcer. SA/PEG scaffolds were prepared by adding different concentrations (1, 3, and 5 wt%) of PEG to 9 wt% SA. The morphological and chemical composition of the resulting 3D printed composite scaffolds was determined using scanning electron microscopy (SEM) and Fourier transforms infrared spectroscopy (FTIR), respectively. Mechanical and thermal properties, swelling, and degradation behaviours were also investigated. The release kinetics of SC were performed. The antimicrobial analysis was evaluated against Escherichia coli and Staphylococcus aureus strains. 3D printed scaffolds have shown an excellent antibacterial effect, especially against gram-positive bacteria due to the antibacterial SC extract they contain. Furthermore, the cell viability of fibroblast (L929) cells on/within scaffolds were determined by the colourimetric MTT assay. The SA/PEG/SC scaffolds show a great promising potential candidate for diabetic wound healing and against bacterial infections. (c) 2020 Elsevier B.V. All rights reserved.Publication Open Access Synthesis and characterization of interpenetrating network (IPN) based levan-polyacrylamide hydrogels and their application in conservation of cultural heritage(2023-11-01) ÜNAL YILDIRIM, SEMRA; OKTAR, FAİK NÜZHET; GENÇ, SEVAL; TOKSOY ÖNER, EBRU; Özen Sağlam R., Ünal Yıldırım S., Oktar F. N., Genç S., Erdem G., Toksoy Öner E.In this study, an IPN based enzymatic levan-polyacrylamide hydrogel (EL-PA) was developed and characterized for its structural, morphological, rheological properties and swelling kinetics to underline hydrogel properties and its potential use in paper conservation. The addition of levan also led to changes in the viscoelastic behavior of the hydrogels, with the complex viscosity of EL-PA samples showing pronounced dependence on shear rate. The swelling and the overall surface area of the hydrogels were increased with the addition of levan into the polymer network. Source associated structural differences were found to be negligible such that both microbially produced linear and enzymatically produced branched forms of levan performed equally well. Solvent loaded hydrogels were then applied on an artifact, a 19th century book of Namık Kemal, and investigated using FTIR, SEM, XRD and colorimetric analysis. Old adhesive layers were successfully removed, and hydrogels showed good compatibility and ease of application. This study has shown that levan has improved hydrogel properties and levan based systems bear high potential in conservation science.Publication Metadata only Part 2: biocompatibility evaluation of hydroxyapatite-based clinoptilolite and Al2O3 composites(SPRINGER, 2017) OKTAR, FAİK NÜZHET; Kalkandelen, C.; Suleymanoglu, M.; Kuruca, S. E.; Akan, A.; Oktar, F. N.; Gunduz, O.The biocompatibility of clinoptilolite/alumina/bovine hydroxyapatite (Cp - Al2O3 - BHA) composite, at different ratio obtained by powder pressing process, were investigated studying the behavior of osteosarcoma (SAOS-2) cells. The biocompatibility was examined by means of cytotoxicity and cytocompatibility tests. The structure and morphology of bioceramic composites were studied by scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR) technique. The results showed that these materials have no toxic effects. The natural composite that fabricated in this study may be a promising approach for bone engineering applications.Publication Metadata only Studies on goat hydroxyapatite/commercial inert glass biocomposites(SPRINGER, 2019) OKTAR, FAİK NÜZHET; Akyurt, N.; Yetmez, M.; Oktar, F. N.In this study, mechanical properties and microstructural analysis of goat-derived hydroxyapatite/commercial inert glass biocomposites are considered in the temperature range between 1000 and 1300 degrees C. The results indicate that the best values of maximum compressive strength and microhardness are achieved in the samples sintered at 1200 degrees C for the glass in the weight of 5 and 10%. Moreover, above 1000 degrees C, decomposition of hydroxyapatite and new phase formations such as whitlockite and silicocarnotite play also a major role in the hardness and strength for goat hydroxyapatite/commercial inert glass biocomposites.Publication Metadata only Hydroxyapatite-TiO2 composites(ELSEVIER SCIENCE BV, 2006) OKTAR, FAİK NÜZHET; Oktar, FNThis article reports the mechanical properties, the microstructure, and the crystallography of composite materials made of hydroxyapatite, obtained from natural bovine bone, and TiO2 (5 and 10 wt.%), which were sintered at different temperatures between 1000 and 1300 degrees C. Higher sintering temperatures resulted in better densification. The samples sintered at 1300 degrees C had the highest microhardness. The best compressive strengths were obtained after sintering at 1300 degrees C for the samples containing 5% TiO2, and at 1200 degrees C for the samples with 10% TiO2. (c) 2005 Elsevier B.V. All rights reserved.Publication Metadata only Hydroxyapatite nano-powders produced hydrothermally from nacreous material(ELSEVIER SCI LTD, 2006) OKTAR, FAİK NÜZHET; Lemos, A. F.; Rocha, J. H. G.; Quaresma, S. S. F.; Kannan, S.; Oktar, F. N.; Agathopoulos, S.; Ferreira, J. M. F.Nano-powders of pure AB-type carbonated hydroxyapatite (HA) sized of similar to 100 nm were successfully produced via hydrothermal transformation (HT) of milled oyster shell powders at 200 degrees C. Low production cost, worldwide availability and natural-biological origin of raw materials are important features of the investigated process. When fine shell powders were used, the transformation reaction from aragonite to hydroxyapatite was accomplished within about 24 h. Calcite, concentrated at the outer surface of the shells, was less prone to transform into hydroxyapatite under the investigated hydrothermal conditions, even after prolonged reaction time (72 h) or in highly concentrated phosphate solutions. (c) 2006 Elsevier Ltd. All rights reserved.