Scopus İndeksli Yayınlar Koleksiyonu / Scopus Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7148
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Article Citation - WoS: 6Citation - Scopus: 8Development of Pro-Angiogenic Wound Dressings From 2-Deoxy (2ddr)-Loaded Decellularized Plant Leaves(SPRINGER, 2023) Dikici, Serkan; Çavdaroğlu, ÇağrıTraditional wound dressings are essential for the treatment of acute and superficial wounds. However, complex wounds require the use of bioactive dressings that promote healing alongside providing a safe barrier for the coverage of the wound site. The addition of growth factors is usually the primary choice to fabricate functionalized wound dressing. However, it is also the main reason for the increase in the cost of a wound dressing and may be associated with several drawbacks, such as the need for a precise drug delivery system to be able to be administered at a narrow effective dose range. 2-deoxy-D-ribose (2dDR) is a cost-effective and promising pro-angiogenic agent that indirectly stimulates vascular endothelial growth factor production to stimulate angiogenesis, and consecutively accelerate wound healing. In this study, we aimed to fabricate a novel wound dressing from 2dDR-loaded decellularized spinach leaves and evaluated its bioactivity on human endothelial cells in vitro. Our results demonstrated that a biocompatible wound dressing biomaterial could successfully be fabricated via the decellularization of spinach leaves using chemical decellularization. The success of decellularization was confirmed quantitatively and qualitatively via determination of the DNA content and Fourier transform infrared spectroscopy, respectively. 2dDR was then easily incorporated into the dressings via physical absorption and released from them in 5 days. The release of 2dDR-releasing decellularized spinach leaves was observed to increase the viability and metabolic activity of human endothelial cells in vitro over 7 days. In conclusion, we demonstrated the fabrication of a novel functionalized biomaterial combining decellularized plant tissues with a promising pro-angiogenic agent, and 2dDR-loaded decellularized spinach leaves appear to have great potential to be used as a bioactive wound dressing to promote angiogenesis and, consecutively, wound healing.Article Citation - WoS: 9Citation - Scopus: 11Electrospun Polyacrylonitrile (pan)/Polypyrrole (ppy) Nanofiber-Coated Quartz Crystal Microbalance for Sensing Volatile Organic Compounds(Springer, 2023) Yağmurcukardeş, Nesli; İnce Yardımcı, Atike; Yağmurcukardeş, Mehmet; Çapan, İnci; Erdoğan, Matem; Çapan, Rifat; Açıkbaş, YaserIn this study, electrospun polyacrylonitrile (PAN)/polypyrrole (PPy) nanofibers (NFs) coated quartz crystal microbalance (QCM) were investigated for their sensing characteristics against six different volatile organic compounds (VOCs): chloroform, dichloromethane, carbon tetrachloride, benzene, toluene and xylene. SEM, TEM, FT-IR and TGA analysis were carried out for the characterization of PAN/PPy nanofibers and characterization results of PAN/PPy NFs showed that these nanofibers were morphologically well-arranged and straightforward with a cylindrical shape with the average fiber diameter of 253.17 +/- 27 nm. Among all the gas measurement tests, dichloromethane displayed the highest response values for PAN/PPy coated QCM sensors. When the reproducibility of kinetic studies for PAN/PPy NFs coated QCM sensors were examined, the most repetitive results were obtained by this QCM sensor during dichloromethane investigation and the diffusion coefficients of VOCs for the first and second regions increased with the order of xylene < toluene < benzene < carbontetrachloride < chloroform < dichloromethane. The sensitivities of the PAN/PPy nanofibers-coated QCM sensor against organic vapors are determined between 4.71 and 6.17 (Hz ppm(-1)) x 10(-4). As a result, PAN/PPy nanofibers exhibited high sensitivity and selectivity for VOCs sensor applications, especially for dichloromethane.Article Citation - WoS: 7Citation - Scopus: 7Investigating the Effects of Pa66 Electrospun Nanofibers Layered Within an Adhesive Composite Joint Fabricated Under Autoclave Curing(American Chemical Society, 2023) Esenoğlu, Gözde; Tanoğlu, Metin; Barışık, Murat; İplikçi, Hande; Yeke, Melisa; Nuhoğlu, Kaan; Türkdoğan, Ceren; Martin, Seçkin; Aktaş, Engin; Dehneliler, Serkan; Gürbüz, Ahmet Ayberk; İriş, Mehmet ErdemEnhancing the performance of adhesively joined composite components is crucial for various industrial applications. In this study, polyamide 66 (PA66) nanofibers produced by electrospinning were coated on unidirectional carbon/epoxy prepregs to increase the bond strength of the composites. Carbon/epoxy prepregs with/without PA66 nanofiber coating on the bonding region were fabricated using the autoclave, which is often used in the aerospace industry. The single lap shear Charpy impact energy and Mode-I fracture toughness tests were employed to examine the effects of PA66 nanofibers on the mechanical properties of the joint region. Scanning electron microscopy (SEM) was used to investigate the nanofiber morphology and fracture modes. The thermal characteristics of Polyamide 66 nanofibers were explored by using differential scanning calorimetry (DSC). We observed that the electrospun PA66 nanofiber coating on the prepreg surfaces substantially improves the joint strength. Results revealed that the single lap shear and Charpy impact strength values of the composite joint are increased by about 79 and 24%, respectively, by coating PA66 nanofibers onto the joining region. The results also showed that by coating PA66 nanofibers, the Mode-I fracture toughness value was improved by about 107% while the glass transition temperature remained constant.Article Citation - WoS: 17Citation - Scopus: 16Development of Cissus Quadrangularis-Loaded Poss-Reinforced Chitosan-Based Bilayer Sponges for Wound Healing Applications: Drug Release and in Vitro Bioactivity(American Chemical Society, 2023) Değer Aker, Sibel; Tamburacı, Sedef; Tıhmınlıoğlu, FundaNowadays, antibiotic-loaded biomaterials have been widelyusedin wound healing applications. However, the use of natural extractshas come into prominence as an alternative to these antimicrobialagents in the recent period. Among natural sources, Cissus quadrangularis (CQ) herbal extract is usedfor treatment of bone and skin diseases in ayurvedic medicine dueto its antibacterial and anti-inflammatory effects. In this study,chitosan-based bilayer wound dressings were fabricated with electrospinningand freeze-drying techniques. CQ extract-loaded chitosan nanofiberswere coated on chitosan/POSS nanocomposite sponges using an electrospinningmethod. The bilayer sponge is designed to treat exudate wounds whilemimicking the layered structure of skin tissue. Bilayer wound dressingswere investigated with regard to the morphology and physical and mechanicalproperties. In addition, CQ release from bilayer wound dressings and in vitro bioactivity studies were performed to determinethe effect of POSS nanoparticles and CQ extract loading on NIH/3T3and HS2 cells. The morphology of nanofibers was investigated withSEM analysis. Physical characteristics of bilayer wound dressingswere determined with FT-IR analysis, swelling study, open porositydetermination, and mechanical test. The antimicrobial activity ofCQ extract released from bilayer sponges was investigated with a discdiffusion method. Bilayer wound dressings' in vitro bioactivity was examined using cytotoxicity determination, woundhealing assay, proliferation, and the secretion of biomarkers forskin tissue regeneration. The nanofiber layer diameter was obtainedin the range of 77.9-97.4 nm. The water vapor permeabilityof the bilayer dressing was obtained as 4021 to 4609 g/m(2)day, as it is in the ideal range for wound repair. The release ofthe CQ extract over 4 days reached 78-80% cumulative release.The release media were found to be antibacterial against Gram-negativeand Gram-positive bacteria. In vitro studies showedthat both CQ extract and POSS incorporation induced cell proliferationas well as wound healing activity and collagen deposition. As a result,CQ-loaded bilayer CHI-POSS nanocomposites were found as a potentialcandidate for wound healing applications.Article Citation - WoS: 6Citation - Scopus: 6Nanolitography Based on Electrospun and Etched Nanofibers(Elsevier, 2021) Noori, Aileen; Döğer, Hilal; Demirhan, Yasemin; Özdemir, Mehtap; Özyüzer, Lütfi; Aygün, Gülnur; Sağlam, ÖzgeIn this study, we propose a new type of nanolithography procedure to fabricate orderly patterned metallic nanostructures using the electrohydrodynamic method and the reactive ion etching process. The electrohydrodynamic process parameters were tuned so as to create patterning with precision, and fibers in nanoscale on silver-coated substrates. We also studied reactive ion etching with different durations on the well-patterned samples. The experiments show that applying a voltage of 400 V resulted in straight patterned fibers with a diameter of 208.7 ? 30.3 nm. The statistical analysis on scanning electron microscope (SEM) images showed a significant difference in the diameter of the fibers fabricated at 400 V compared to those at 500 V and 600 V. We also confirm that the etching process has no affect on the fiber diameter. Moreover, electron dispersive X-Ray spectrometer (EDX) results suggest that an etching duration of 7 min is sufficient to remove the silver coating that is not covered with the fibers, and protect the silver nanostructures underneath the fibers. Utilizing a lowcost nanolithography procedure, we obtain the orderly patterned silver nanostructures for possible integration into miniaturized devices.Article Citation - WoS: 1Citation - Scopus: 1Fabrication and in Vitro Evaluation of Thermally Cross-Linked Gelatin Nanofibers for Drug Delivery Applications(Taylor & Francis, 2022) Mete, Derya; Göktaş, Gözde; Şanlı Mohamed, GülşahIn this study, four different nanofibers consisting of gelatin (Gel), doxorubicin (DOX) with gel (DOX@Gel), a composite of gel with poly(ethylene glycol) (PEGylated-gel), and DOX@PEGylated-gel were fabricated. Subsequently, the nanofibers were thermally cross-linked in order to offer a stable and biocompatible alternative for the biological applications of nanofibers such as drug delivery and tissue engineering. Nanofibers were characterized by scanning electron microscopy, Fourier Transform-Infrared Spectroscopy (FT-IR), and confocal microscopy. The formation of smooth, continuous, and uniform nanofibers was observed and the addition of PEG resulted in an increase whereas the incorporation of DOX into nanofibers had no significant change in the diameter of nanofibers. Crosslinking also enlarged the diameter of all nanofibers and the most dramatic increase was observed 53% by DOX@PEGylated-gel. Afterward, the biological performance of the nanofibers was investigated by drug release profile, cytotoxicity on A549 cell line as well as antimicrobial activity with E. coli and S. aureus. The results indicate an enhanced drug release profile, moderate antimicrobial activity, and reasonable cytotoxic efficiency for thermally cross-linked nanofibers compared to uncross-linked nanofibers.Article Citation - WoS: 11Citation - Scopus: 13Effect of Cnt Incorporation on Pan/Ppy Nanofibers Synthesized by Electrospinning Method(TÜBİTAK, 2020) İnce Yardımcı, Atike; Tanoğlu, Metin; Yılmaz, Selahattin; Selamet, YusufIn this study, carbon nanotubes (CNTs) added polyacrylonitrile/polypyrrole (PAN/PPy) electrospun nanofibers were produced. Average diameters of the nanofibers were measured as 268 and 153 nm for 10 and 25 wt% of PPy contents, respectively. A relatively higher strain to failure values (23.3%) were observed for the low PPy content. When as-grown CNTs (1 and 4 wt%) were added into the PAN/PPy blends, disordered nanofibers were observed to form within the microstructure. To improve the interfacial properties of CNTs/PAN/PPy composites, CNTs were functionalized with H2SO4/HNO3/HCl solution. The functionalized CNTs were well dispersed within the nanofibers and aligned along the direction of nanofibers. Therefore, beads formation on nanofibers decreased. The impedance of the nanofibers was found to decrease with the PPy content and CNT addition. These nanofibers had a great potential to be used as an electrochemical actuator or a tissue engineering scaffold.Article Citation - WoS: 34Citation - Scopus: 39Aptamer-Based Electrochemical Biosensing Strategy Toward Human Non-Small Cell Lung Cancer Using Polyacrylonitrile/Polypyrrole Nanofibers(Springer, 2020) Kıvrak, Ezgi; İnce Yardımcı, Atike; İlhan, Recep; Ballar Kırmızıbayrak, Petek; Yılmaz, Selahattin; Kara, PınarIn the present study, a sensitive electrochemical aptamer-based biosensing strategy for human non-small cell lung cancer (NSCLC) detection was proposed using nanofiber-modified disposable pencil graphite electrodes (PGEs). The composite nanofiber was comprised of polyacrylonitrile (PAN) and polypyrrole (PPy) polymers, and fabrication of the nanofibers was accomplished using electrospinning process onto PGEs. Development of the nanofibers was confirmed using scanning electron microscopy (SEM). The high-affinity 5 '-aminohexyl-linked aptamer was immobilized onto a PAN/PPy composite nanofiber-modified sensor surface via covalent bonding strategy. After incubation with NSCLC living cells (A549 cell line) at 37.5 degrees C, the recognition between aptamer and target cells was monitored by electrochemical impedance spectroscopy (EIS). The selectivity of the aptasensor was evaluated using nonspecific human cervical cancer cells (HeLa) and a nonspecific aptamer sequence. The proposed electrochemical aptasensor showed high sensitivity toward A549 cells with a detection limit of 1.2 x 10(3)cells/mL. The results indicate that our label-free electrochemical aptasensor has great potential in the design of aptasensors for the diagnostics of other types of cancer cells with broad detection capability in clinical analysis.Article Citation - WoS: 25Citation - Scopus: 27Osteogenic Differentiation of Mesenchymal Stem Cells on Random and Aligned Pan/Ppy Nanofibrous Scaffolds(SAGE Publications, 2019) Selamet, Yusuf; İnce Yardımcı, Atike; Baskan, Öznur; Yılmaz, Selahattin; Meşe, Gülistan; Özçivici, EnginThe aim of this study was to develop random and aligned polyacrilonitrile (PAN)/polypyrrole (PPy) nanofibrous scaffolds by electrospinning technique for osteogenic differentiation of mesenchymal stem cells. Nanofibers were fabricated successfully as straight, smooth, and free from bead formation. The average diameter of random and aligned nanofibers was 268(+/- 49) nm and 225(+/- 72) nm, respectively. Alignment process increased the tensile strength of nanofibers 3.9-fold, while the tensile strain of nanofibers decreased by 78%. PAN/PPy nanofibers were hydrophilic with the contact angle value of about 32 degrees and alignment did not affect the contact angle value. Random and aligned PAN/PPy nanofibers were investigated as a scaffold material for osteogenic differentiation of D1 ORL UVA mouse bone marrow mesenchymal stem cells. Cells were able to attach and grow on nanofibers confirmed by cell viability results. Stem cells that were cultured with osteogenic induction were able to mineralize on electrospun nanofibers based on alizarin red and Von Kossa dye staining. For aligned PPy nanofibers, mineralization occurred in the fiber alignment direction. Consequently, PAN/PPy nanofibrous mats in both random and aligned forms would be potential candidates for bone tissue engineering.Article Citation - WoS: 63Citation - Scopus: 65Amidoxime Functionalized Polymers of Intrinsic Microporosity (pim-1) Electrospun Ultrafine Fibers for Rapid Removal of Uranyl Ions From Water(Elsevier Ltd., 2019) Satılmış, Bekir; Isık, Tuğba; Demir, Mustafa Muammer; Uyar, TamerThe Polymers of Intrinsic Microporosity (PIM-1) is considered as one of the most promising polymer candidates for adsorption applications owing to its high surface area and the ability to tailor the functionality for the targeted species. This study reports a facile method for the preparation of amidoxime functionalized PIM-1 fibrous membrane (AF-PIM-FM) by electrospinning technique and its practical use for the extraction of U(VI) ions from aqueous systems via column sorption under continuous flow. Fibrous membrane form of amidoxime functionalized PIM-1 (AF-PIM-FM) was prepared by electrospinning method owing to its excellent processability in dimethylformamide. Bead-free and uniform fibers were obtained as confirmed by SEM imaging and average fiber diameter was 1.69 +/- 0.34 mu m for AF-PIM-FM. In addition, electrospun PIM-1 fibrous membrane (PIM-FM) was prepared as a control group. Structural and thermal characterization of powder and membrane forms of the materials were performed using FT-IR, H-1 NMR, XPS, Elemental analyses, TGA, and DSC. The porosity of the samples was measured by N-2 sorption isotherms confirming amidoxime PIM-1 still maintain their porosity after functionalization. Amidoxime functionality along with membrane structure makes AF-PIM-FM a promising material for uranyl adsorption. First, a comparison between powder and membrane form of amidoxime functionalized PIM-1 was investigated using batch adsorption process. Although membrane form has shown slightly lower adsorption performance in the batch adsorption process, the advantage of using the membrane in column adsorption processes makes membrane form more feasible for real applications. In addition, amidoxime modification enhanced the uranium adsorption ability of PIM-FM up to 20 times. The effect of initial concentration and pH were investigated along with regeneration of the adsorbents. AF-PIM-FM was successfully used for five adsorption-desorption cycles without having any damage on the fibrous structure.