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Article Citation - WoS: 1Citation - Scopus: 1PMMA-Based Electrospun Composite Fibers for Dye Adsorption From Water(Sage Publications Ltd, 2025) Cakar, Ilknur; Yesil, Sertan; Bayram, GoknurPoly (methyl methacrylate) (PMMA) and PMMA/poly (ethylene glycol) (PEG)-based composite fibers were produced using electrospinning technique with two different additives; halloysite nanotubes (HNTs) and boron phosphate (BPO4). The effect of the additives on the morphology, wettability and dye adsorption properties of electrospun fibers were investigated by Scanning Electron Microscopy (SEM), water contact angle measurement and UV-VIS spectrophotometry. The results of SEM analysis indicated that addition of PEG resulted in thinner average fiber diameter and beaded structure. Additionally, it was also observed that incorporating both HNT and BPO4 to the PMMA solution caused increased fiber diameter which might be due to increased solution viscosity. For PMMA fibers containing 3 wt% HNT, the highest average diameter and water contact angle were measured as 2204 +/- 302 nm and 110.29 +/- 3.9 degrees, respectively. The produced fibers were tested for the capability to adsorb methylene blue (MB) and methyl orange (MO) from aqueous solutions. Dye adsorption capacity of the samples increased by addition of HNT and BPO4. According to adsorption capacity results, PMMA/PEG/BPO4 composite sample containing 5 wt% BPO4, with an adsorption capacity of 0.76 mg/g, was determined as adsorbent for kinetic and isotherm studies. The adsorption kinetics were well described by the pseudo-second-order model, and equilibrium data were correlated with the Langmuir model.Article Citation - WoS: 14Citation - Scopus: 14Membrane Supported Poly(butylene Adipate-Co Nanofibrous Matrices as Cardiac Patch: Effect of Basement Membrane for the Fiber Deposition and Cellular Behavior(Elsevier, 2022) Gultan, Tugce; Gumusderelioglu, MenemseElectrospun nanofibrous matrices are convenient biomaterials that mimic extracellular matrices for adhesion, migration, proliferation, and differentiation of cells. The aim of this study is to optimize the electrospinning parameters for poly(butylene adipate-co-terephthalate) (PBAT) nanofiber production by the response surface methodology (RSM) and to develop a suitable material design for the usability of PBAT in cardiac tissue engineering. Therefore, electrospun PBAT nanofibrous matrices collected on solvent-casted polycaprolactone (PCL) or PBAT basement membranes at optimized conditions. The attachment and proliferation behavior of the H9C2 rat cardiomyoblasts investigated on different PBAT and PCL surface features as a model cell line. For this purpose, neat PBAT and PCL films have been used comparatively with both random (R-PBAT) and aligned PBAT (A-PBAT) nanofibers coated films. The effect of polymer concentration, flow rate, applied voltage, and needle tip -connector distance on fiber diameter and alignment was examined in the electrospinning process and optimum processing parameters were determined by RSM. The PBAT nanofibers were spun on basement membranes with 10% (w/v) polymer concentration, 1 mL/h volumetric flow rate, 2000 rpm collector rotation velocity (for aligned ones), 15 kV applied voltage, and 20 cm needle tip-collector distance. The average diameter of random (R-PBAT) and aligned (A-PBAT) nanofibers was calculated as 555 +/- 126 nm and 417 +/- 137 nm. The mechanical test results showed that the alignment topography increased the elastic modulus of PBAT nanofibers compared to random matrices. The alignment of fibers found as 91% and 75% within the +/- 10? range for A-PBAT/SC-PBAT and A-PBAT/SC-PCL, respectively. These findings showed that usage of PCL, instead of PBAT, as basement membrane decrease the alignment of deposited nanofibers. A 7-day cell culture study conducted with H9C2 cells seeded samples to investigate the influence of these differences on cell behavior. The results indicated that the alignment of fibers provides a suitable topography to proliferate and spread in myocyte morphology for H9C2 cells especially compared to neat films. Cellular behavior and nanofiber deposition have been affected by the usage of various basement membrane polymers. These findings demonstrated that the usage of basement membrane as support material provides the required thickness and mechanical properties to the aligned PBAT nanofiber matrices, and this double layer structure might be a promising candidate for cardiac tissue engineering with further studiesArticle Citation - WoS: 39Citation - Scopus: 44A Novel Treatment Strategy for Preterm Birth: Intra-Vaginal Progesterone-Loaded Fibrous Patches(Elsevier, 2020) Cam, Muhammet Emin; Hazar-Yavuz, Ayse Nur; Cesur, Sumeyye; Ozkan, Ozan; Alenezi, Hussain; Sasmazel, Hilal Turkoglu; Edirisinghe, MohanProgesterone-loaded poly(lactic) acid fibrous polymeric patches were produced using electrospinning and pressurized gyration for infra-vaginal application to prevent preterm birth. The patches were intravaginally inserted into rats in the final week of their pregnancy, equivalent to the third trimester of human pregnancy. Maintenance tocolysis with progesterone-loaded patches was elucidated by recording the contractile response of uterine smooth muscle to noradrenaline in pregnant rats. Both progesterone-loaded patches indicated similar results from release and thermal studies, however, patches obtained by electrospinning had smaller average diameters and more uniform dispersion compared to pressurized gyration. Patches obtained by pressurized gyration had better results in production yield and tensile strength than electrospinning; thereby pressurized gyration is better suited for scaled-up production. The patches did not affect cell attachment, viability, and proliferation on Vero cells negatively. Consequently, progesterone-loaded patches are a novel and successful treatment strategy for preventing preterm birth.Article Citation - Scopus: 1Surface Patterning of Poly(ε-Caprolactone) Scaffolds by Electrospinning for Monitoring Cell Biomass Behavior(Springer, 2022) Albayrak, Deniz; Sasmazel, Hilal TurkogluThe aim of this work was to produce three-dimensional fibrous surface patterns of poly(epsilon-caprolactone) (PCL), onto two-dimensional smooth solvent cast PCL surfaces with an electrospinning method by using a mask/stencil for monitoring cell biomass behavior. The characterizations of produced scaffolds were done by thickness measurements, scanning electron microscopy (SEM) analyses, contact angle (CA) measurements, Fourier-transform infrared spectroscopy (FTIR), and mechanical tests. According to SEM micrographs, all of the electrospun scaffold surfaces exhibited bead-free and uniform morphology while solvent cast surfaces were smooth and nonporous. CA measurements revealed that the solvent cast surfaces had moderate hydrophilicity (similar to 60 degrees) while electrospun regions had a more hydrophobic character (similar to 110 degrees for fully electrospun surfaces and similar to 85 degrees for electrospun patterns). Mechanical testing showed the produced scaffolds had a brittle character. Moreover, cell culture studies were performed with mouse fibroblast (L929) cells for 7 days period, and cell attachment assay, MTT assay, fluorescence, and SEM analyses were done. Cell culture studies indicated that the solvent cast and electrospun patterns have different characteristics for cell behavior. Thus, cell movement, attachment, and proliferation can be directed and monitored by obtaining different surface topographies in a single substrate surface. Based on the results of this study, it was found that patterns consisting of polymeric nanofiber structures can also be created directly by the electrospinning method.Article Citation - WoS: 64Citation - Scopus: 70Nanosized Cap-Silk Fibroin-pcl-peg-pcl/Pcl Based Bilayer Membranes for Guided Bone Regeneration(Elsevier Science Bv, 2017) Turkkan, Sibel; Pazarceviren, A. Engin; Keskin, Dilek; Machin, Nesrin E.; Duygulu, Ozgur; Tezcaner, AysenGuided bone regeneration (GBR) concept has been developed to prevent the formation of non-functional scar tissue layer on defect site by undertaking barrier role. In this study, a new bilayer membrane which consisted of one layer of electrospun silk fibroin/PCL-PEG-PCL incorporating nanocalcium phosphate (SPCA)(1) and one layer of PCL membrane was developed for GBR. To improve the osteoconductivity of membranes, nanosized calcium phosphate particles synthesized by Flame Spray Pyrolysis method were incorporated into membranes at 10% (wt) (SPCA10) and 20% (wt) (SPCA20) of the polymer content. The structural and chemical analyses revealed the well-integrated two layers of membranes with a total thickness of ca 100 mu m. In the regenerative layer, the highly porous mesh structure had a thickness of 12.6 mu m with randomly oriented fibers having diameters around 760 nm, and nanoparticles dispersed homogenously. The mechanical test results showed remarkable improvement on the tensile strength of membranes with incorporation of nanoparticles. Higher water affinity of nanoCaP included membranes was proved by lower contact angle values and higher percent water uptake capacity. Biomineralization assay revealed that nucleation and growth of apatites around fibers of SPCA10 and SPCA20 were apparent while on SPCAO apatite minerals were barely detected after 10 days. Human dental pulp stem cells (DPSC) were seeded on electrospun layer of the bilayer membranes for biocompatibility and osteo-compatibility study. Increasing narioCaP amount resulted in higher cell adhesion, proliferation, ALP activity and calcium deposition on membranes. These overall results confirmed the biocompatibility and potential applicability of proposed membranes for GBR treatments. (C) 2017 Elsevier B.V. All rights reserved.Article Citation - WoS: 45Citation - Scopus: 46Novel Hybrid Scaffolds for the Cultivation of Osteoblast Cells(Elsevier, 2011) Sasmazel, Hilal TurkogluIn this study, natural biodegradable polysaccharide, chitosan, and synthetic biodegradable polymer, poly(epsilon-caprolactone) (PCL) were used to prepare 3D, hybrid polymeric tissue scaffolds (PCL/chitosan blend and PCL/chitosan/PCL layer by layer scaffolds) by using the electrospinning technique. The hybrid scaffolds were developed through HA addition to accelerate osteoblast cell growth. Characteristic examinations of the scaffolds were performed by micrometer, SEM, contact angle measurement system, ATR-FTIR, tensile machine and swelling experiments. The thickness of all electrospun scaffolds was determined in the range of 0.010 +/- 0.001-0.012 +/- 0.002 mm. In order to optimize electrospinning processes, suitable bead-free and uniform scaffolds were selected by using SEM images. Blending of PCL with chitosan resulted in better hydrophilicity for the PCL/chitosan scaffolds. The characteristic peaks of PCL and chitosan in the blend and layer by layer nanofibers were observed. The PCL/chitosan/PCL layer by layer structure had higher elastic modulus and tensile strength values than both individual PCL and chitosan structures. The layer by layer scaffolds exhibited the PBS absorption values of 184.2; 197.2% which were higher than those of PCL scaffolds but lower than those of PCL/chitosan blend scaffolds. SaOs-2 osteosarcoma cell culture studies showed that the highest ALP activities belonged to novel PCL/chitosan/PCL layer by layer scaffolds meaning better cell differentiation on the surfaces. (C) 2011 Elsevier B.V. All rights reserved.Article Development of Electrospun We43 Magnesium Alloy-Like Compound(Amer Scientific Publishers, 2020) Ozkan, Ozan; Sasmazel, Hilal Turkoglu; Biskin, ErhanMetallic structures are conventionally fabricated with high temperature/deformation processes resulting the smallest possible microscopic structures in the order of several hundreds of micrometer. Therefore, to obtain structures with fibers smaller than 100 Am, those are unsuitable. In this study, electrospinning, a fiber fabrication technique commonly used for polymers, was adopted to fabricate a WE43 magnesium alloy-like fibrous structure. The aim is to adopt metallic WE43 alloy to regenerative medicine using tissue engineering approach by mimicking its composition inside of a fibrous structure. The solution required for electrospinning was obtained with water soluble nitrates of elements in WE43 alloy, and PVP or PVA were added to obtain a spinnable viscosity which was pyrolised away during heat treatment. Electrospinning parameters were optimized with naked-eye observations and SEM as 1.5 g salts and 5 wt.% PVA containing solution prepared at 90 degrees C and electrospun under 30 kV from a distance of 12-15 cm with a feeding rate of 5 mu l/min. Then the samples were subjected to a multi-step heat treatment under argon to remove the polymer and calcinate the nitrates into oxides which was designed based on thermal analyses and reaction kinetics calculations as 6 h at 230 degrees C, 8.5 h at 390 degrees C, 5 h at 465 degrees C, 80 h at 500 degrees C and 10 h at 505 degrees C, consecutively. The characterizations conducted in terms of structure, composition and crystallinity with XRD, XPS, EDX and SEM showed that it is possible to obtain MgaYbNdcZrdOx), (empirical) fibers with the same composition as WE43 in sub-millimeter sizes using this approach.Article Citation - WoS: 21Development of Poly(vinyl Alcohol) (pva)/Reduced Graphene Oxide (rgo) Electrospun Mats(Amer Scientific Publishers, 2019) Gozutok, Melike; Sadhu, Veera; Sasmazel, Hilal TurkogluIn this study, electrospun reduced graphene oxide (rGO) and poly(vinyl alcohol) (PVA) nanocomposites were developed with the concentration of rGO as 0.5 and 1.0 wt% by dispersing rGO in the PVA solution without using any co-solvent which may cause toxic effect for possible applications like packaging and tissue engineering. Water solubility of PVA was eliminated by UV-radiation crosslinking method. SEM analysis proved that continuous and bead-free nanofibers were obtained by electrospinning process and all electrospun mats had similar fiber characteristics with homogeneous fiber morphology. The average fiber diameter (nm), inter-fiber pore size (mu m) and the porosity (%) were increased with rGO incorporation. Additionally, enhanced tensile properties was achieved by rGO addition as the highest tensile strength was obtained as similar to 5 MPa for electrospun PVA+ 1.0 wt% rGO nanocomposites. ATR-FTIR analyses showed that there was a relatively strong interfacial interaction between rGO and PVA. Moreover, the thermal stability of obtained nanocomposites was enhanced by rGO addition without changing the crystal structure of PVA proved by XRD analyses. Also, improved electrical conductivity of the nanocomposites was obtained by rGO content as the highest conductivity (similar to 11 mu S.cm(-1)) was measured for electrospun PVA+ 1.0 wt% rGO.Book Part Poly(ε-caprolactone)/Chitosan Nanostructures for Cell Cultivation(Springer, 2020) Turkoglu Sasmazel,H.Hybridization of synthetic poly (ε-caprolactone) (PCL) and natural chitosan polymers to develop PCL/chitosan core-shell nanostructures for cell cultivation was aimed in this study. Coaxial electrospinning method was used for the fabrication of the nanostructures. The characterizations of the samples were done by X-ray photoelectron spectroscopy (XPS) analyses and mechanical tests. XPS analysis of the PCL/chitosan core-shell structures exhibited the characteristic peaks of PCL and chitosan polymers. The cell culture studies, MTT assay and Confocal Laser Scanning Microscopy (CLSM), carried out with L929 ATCC CCL-1 mouse fibroblast cell line, proved the biocompatibility of all materials. The cell viability on the hybrid nanostructures was ~two times better then on tissue culture polystyrene (TCPS) because of its three dimensional (3D) extracellular matrix (ECM)-like structure compared to 2D flat surface of commercially cell compatible TCPS. The performance was ~two times and ~ten times better compared to single PCL and single chitosan, respectively, even though both fabricated similarly by electrospinning as non-woven fibrous structures, because were either too hydrophobic or too hydrophilic to maintain cell attachment points. © Springer Nature B.V. 2020.
