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 Open Access Bioinspired bubble design for particle generation(ROYAL SOC, 2012-02-07) GÜNDÜZ, OĞUZHAN; Gunduz, Oguzhan; Ahmad, Zeeshan; Stride, Eleanor; Tamerler, Candan; Edirisinghe, MohanIn this study, we devise a method to generate homogeneous particles from a bubble suspension, with the capability to control loading and the structure of bubbles. Ideally, a process such as this would occur at the interface between daughter bubble formation (instant) and gaseous diffusion (gradual). Interestingly, the budding mechanism in micro-organisms is one that demonstrates features of the desired phenomena (although at a much slower rate), as viruses can eject and evolve structures from their membranes. With these natural concepts, a bubble's surface can also be made to serve as a platform for particle generation, which transfers significant elements from the initial bubble coating to the newly generated structures. Here, we illustrate this by preparing coated bubbles (approx. 150 mm in diameter) using a hydrophobic polymer, which may be comparable to naturally occurring bubble coatings (e. g. organic matter forming part of bubble coatings in the sea), and dye (which can demonstrate entrapment of smaller quantities of a desired moiety) and then observe particle generation (approx. 500 nm). The process, which may be driven by a polymerosome-forming mechanism, also illustrates how additional uniform sub-micrometre-scale structures may form from a bubble's surface, which may have also previously been attributed to gas diffusion. In addition, such methods of particle formation from a bubble structure, the incorporation of chemical or biological media via an in situ process and subsequent release technologies have several areas of interest across the broad scientific community.Publication Open Access A novel multi-target strategy for Alzheimer?s disease treatment via sublingual route: Donepezil/memantine/curcumin-loaded nanofibers(2022-07-01) BÖCEKÇİ, VEYSEL GÖKHAN; GÜNDÜZ, OĞUZHAN; ERTAŞ, BÜŞRA; Topal F., ERTAŞ B., Guler E., Gurbuz F., Ozcan G. S., Aydemir O., BÖCEKÇİ V. G., DURUKSU G., ŞAHİN ÇAM C., YAZIR Y., et al.Drug delivery systems that not only show efficacy through multiple therapeutic pathways but also facilitate patient drug use and exhibit a high bioavailability profile represent a promising strategy in the treatment of Alzheimer???s disease (AD). Here, donepezil (DO)/memantine (MM)/curcumin (CUR)-loaded electrospun nanofibers (NFs) were produced for the treatment of AD. DSC, XRD, and FT-IR studies demonstrated the complete incorporation of the drug into PVA/PVP NFs. The disintegration profile was improved by loading the drugs in PVA/PVP with fast wetting (less than 1 s), the start of disintegration (21 s), and dispersion in 110 s. The desired properties for sublingual application were achieved with the dissolution of NFs in 240 s. The cell viability in DO/ MM/CUR-loaded NFs was similar to the control group after 48 h in the cell culture. DO/MM/CUR-loaded NFs enhanced the expressions of BDNF (13.5-fold), TUBB3 (8.9-fold), Neurog2 (5.6-fold), NeuroD1 (5.8-fold), Nestin (166-fold), and GFAP (115-fold). DO/MM/CUR-loaded NFs and powder of these drugs contained in these fibers were daily administered sublingually to intracerebroventricular-streptozotocin (icv-STZ) treated rats. DO/MM/ CUR-loaded NFs treatment improved the short-term memory damage and enhanced memory, learning ability, and spatial exploration talent. Results indicated that the levels of A??, Tau protein, APP, GSK-3??, AChE, and TNF-?? were significantly decreased, and BDNF was increased by DO/MM/CUR-loaded NFs treatment compared to the AD group. In the histopathological analysis of the hippocampus and cortex, neuritic plaques and neurofibrillary nodes were not observed in the rats treated with DO/MM/CUR-loaded NFs. Taken together, the sublingual route delivery of DO/MM/CUR-loaded NFs supports potential clinical applications for AD.Publication Open Access Investigation of the properties of encapsulated hydrophilic and hydrophobic drugs in whey protein microparticles(2022-10-01) ULAĞ, SONGÜL; GÜNDÜZ, OĞUZHAN; Irem Deniz K., Ulağ S., Gündüz O.© 2022 Elsevier B.V.In this study, the amoxicillin (AMX) and rifampicin (RIF) were loaded into the whey protein (WP) to form the hydrophilic and hydrophobic drugs loaded whey protein microparticles. Scanning electron microscopy (SEM) images demonstrated that AMX addition increased the particle size, but RIF addition decreased the dimensions of the particles. The Fourier-transformed infrared spectroscopy (FTIR) results showed that both drugs were successfully loaded into the protein. AMX and RIF were ultimately released from the WP microparticles after 1440 min, according to the drug release test. Two drugs exhibited the same behaviour, but in the first hour, AMX had more release than the RIF.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 Open Access The effect of polycaprolactone/graphene oxide electrospun scaffolds on the neurogenic behavior of adipose stem cells(2022-02-01) PINAR, ERTUĞRUL; ÜNAL YILDIRIM, SEMRA; GÜNDÜZ, OĞUZHAN; HARMAN, FERHAT; Pınar E., Şahin A., Ünal Yıldırım S., Gündüz O., Harman F., Kaptanoğlu E.Stem cell destiny can be controlled with scaffold biomaterials in tissue engineering and regenerative medicine. This study aimed to investigate the neuronal differentiation potential of human adipose tissue-derived mesen- chymal stem cells in graphene nanofiber matrix in vitro. Stem cell isolation was performed from adipose tissue taken from human by mechanical and enzymatic methods. The differentiation potential was examined after incubation of adipose stem cells in normal medium and neural differentiation medium, on graphene oxide (GO) and polycaprolactone (PCL) composite scaffolds produced by electrospinning technique. In vitro studies indi- cated that the presence of GO in PCL scaffold increases an effect on cell attachment, proliferation, infiltration into the scaffold, and neuronal differentiation. Also, unlike subcutaneous tissue, it has been shown immunohis- tochemically that mesenchymal stem cells derived from epidural adipose tissue tend to differentiate into oligodendrocytes.