Person: GÜNDÜZ, OĞUZHAN
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GÜNDÜZ
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OĞUZHAN
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Publication Metadata only Keratin loaded pva/silk fibroin electrospun nanofibers for wound dressing applications(2022-11-26) CESUR, SÜMEYYE; GÜNDÜZ, OĞUZHAN; Tut T. A., Cesur S., Gündüz O.Publication Metadata only Diagnosis of opioid use disorder with high sensitivity and specificity by advanced computational analysis of Fourier transform infrared spectroscopy(ELSEVIER, 2020) GÜNDÜZ, OĞUZHAN; Guleken, Zozan; Unubol, Basak; Toraman, Suat; Bilici, Rabia; Gunduz, Oguzhan; Kuruca, Serap ErdemOpioid use disorder (OUD), which is a chronic disease and widespread public health problem results in death of the patient in the early period. The consumption of opioid depending on the use disorder time, affects blood biochemical parameters. OUD diagnosis can be clinically determined from biochemical values and with the screening tools in substance abuse. However, long-term OUD causes multiple pathological and physiological changes in many organs. Opioid initiated diseases, such as changes in tissue level and molecular level can be detected with advanced diagnostic methods after a long period of usage. It is important to diagnose these changes without causing organ dysfunction. The tests for the diagnose of chronic effects of OUD are expensive and time-consuming. In this study, we used Fourier transform infrared (FTIR) spectroscopy to discriminate the whole blood samples of opioid-addicted patients (n = 20) from healthy persons (n = 14) with an average addiction period of for 8 +/- 5.8 years. We purposed to compare whole blood vibrational results of OUD and HC. In order to identify absorption bands on structures of proteins, lipids and nucleic acids, their corresponding absorbance of band spectra were measured. We had chosen following bands 2959, 2931, 1646, 1550, 1453, 1400, 1314, 1243, 1080, 1079, 1542, 1045, 1467 to identify peak heights and to compare peak height ratios such as H1646 to H1550, H1079 to H1542, H2959 to H2931, H1453 to H1400, H1314 to H1243, H1045 to H1467, H1080 to H1550. Statistically, the p value of group heights were significantly different (p < 0.001). As a chemometric method, features extracted by principal component analysis (PCA) and then classified by linear discriminate analysis (LDA) and support vector machine (SVM) to determine the spectral data of disorder zones. The confidence of specificity and sensitivity and accuracy were obtained as 93.33%, 85%, 80.57% in raw data, and 100%, 100% and 100% in the second derivative respectively. Our research illustrates that whole blood analyses by FTIR, on the selected peak heights may discriminate pathological and healthy structural changes induced long term opioid use disorder.Thus, we have demonstrated that infrared spectroscopy can provide a simple and available diagnostic test for OUD patients.Publication Metadata only Fabrication and characterization of naringenin-loaded poly(lactic acid) (pla) nanofibrous scaffolds(2022-11-26) BİLĞİÇ ALKAYA, DİLEK; CESUR, SÜMEYYE; GÜNDÜZ, OĞUZHAN; Erdağ Z., Yeşil E., Bilğiç Alkaya D., Cesur S., Gündüz O.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 Loading of tuberculosis drugs to nanofiber structures, fiber optimization(2019-06-28) BİLĞİÇ ALKAYA, DİLEK; AYAZ SEYHAN, SERAP; CESUR, SÜMEYYE; GÜNDÜZ, OĞUZHAN; Onurlu H. İ., Bilğiç Alkaya D., Ayaz Seyhan S., Cesur S., Gündüz O.uberculosis is a disease caused by a bacillus called mycobacterium tuberculosis which can be seen in other organs, especially in the lungs. Tuberculosis is an infectious, infectious, inflammatory, acute or chronic-trending bacterial infection. Since the treatment is insufficient with a single drug and the bacilli are resistant to this antibiotic, various antituberculosis drugs are used side by side during the treatment. Side-by-side use of the drugs breaks the resistance of the bacteria but creates a lot of side effects for the patient. We aim to reduce the existing side effects by loading the active agents of rifampicin, isoniazid, pyrazinamide and ethambutol, which are used as antituberculosis drugs, to a biodegradable nanofib. Primarily, PCL polymer material was dissolved in DMF: THF (v / v). After preparing PCL solution in 3%, 6%, 9%, 12% and 15% concentrations, optimization studies were performed by using electrospin device at various voltages. The SEM images of the obtained PCL fibers were examined and drug loading was performed at the suitable PCL concentration. In the planned study, FTIR images of the fibers loaded with the drug will be examined and controlled drug oscillations will be provided at the stomach and intestinal pH as an in vitro trial and spectrophotometric measurements will be taken. The release of drugs loaded into nanofibers are slower due to the wide surface area of the nanofibers, which offers a more controlled drug release.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 Combination of proteasome inhibitors with temozolomide to increase the anti-tumor effect in 3D culture model of glioblastoma(ELSEVIER SCIENCE INC, 2018) YILMAZ GÖLER, AYŞE MİNE; Unal, Semra; Gokce, Tilbe; Arslan, Sema; Yilmaz, Ayse Mine; Gunduz, Oguzhan; Karademir, BetulPublication Metadata only Fabrication and characterization of electrospun GelMA/PCL/CS nanofiber composites for wound dressing applications(2022-12-01) TINAZ, GÜLGÜN; GÜNDÜZ, OĞUZHAN; Pilavci E., Ayran M., Ulubay D., Kaya E., TINAZ G., Ozakpinar O. B., Sancakli A., GÜNDÜZ O.In the present study, the effect of different ratios of GelMA concentration has been exhibited for wound dressing implementation by the electrospinning method using a new polymer combination of Gelatin methacrylate (GelMA)/Polycaprolactone (PCL)/Chitosan (CS). The nanofiber composites were fabricated due to their biocompatible, biodegradable, improved mechanical strength, low degradation rate, and hydrophilic nature to develop cell-mimicking, cell adhesion, proliferation, and differentiation. Different concentrations of GelMA were added to the PCL/CS solution as 5, 10, and 20 wt%, respectively, in the formic acid/acetic acid (7:3) solution. A photoinitiator was added to the solution for photo-crosslinking of GelMA. The influence of different solution concentrations (5, 10, and 20 wt%) on the structure\"s nanofiber production and fiber morphology was examined. SEM micrographs revealed that varied GelMA concentrations resulted in suitable and stable nanofiber composites. The average diameter of nanofiber composites grows as the GelMA concentration rises. FTIR, DSC, tensile test, degradation, and swelling test were evaluated. The results demonstrated that high mechanical strength, hydrophilic properties, and a slow degradation rate were observed with the presence and increment of GelMA concentration within the nanofiber composites. The antibacterial potential of GelMA/PCL/CS nanofiber composites was evaluated against P. aeruginosa and S. aureus using a disc diffusion assay. In vitro cell culture research was conducted by seeding NIH 3T3 fibroblast cells on nanofiber composites, proving these cells\" high cell proliferation rate, viability, and adhesion. 10 wt% GelMA-based nanofiber composites were found to have great potential for wound dressing applications.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.