31 results
Search Results
Now showing 1 - 10 of 31
Review Citation - WoS: 61Citation - Scopus: 72Atmospheric Pressure Plasma Surface Treatment of Polymers and Influence on Cell Cultivation(Mdpi, 2021) Sasmazel, Hilal Turkoglu; Alazzawi, Marwa; Alsahib, Nabeel Kadim AbidAtmospheric plasma treatment is an effective and economical surface treatment technique. The main advantage of this technique is that the bulk properties of the material remain unchanged while the surface properties and biocompatibility are enhanced. Polymers are used in many biomedical applications; such as implants, because of their variable bulk properties. On the other hand, their surface properties are inadequate which demands certain surface treatments including atmospheric pressure plasma treatment. In biomedical applications, surface treatment is important to promote good cell adhesion, proliferation, and growth. This article aim is to give an overview of different atmospheric pressure plasma treatments of polymer surface, and their influence on cell-material interaction with different cell lines.Article Citation - WoS: 11Development of Antibacterial Composite Electrospun Chitosan-Coated Polypropylene Materials(Amer Scientific Publishers, 2018) Gozutok, Melike; Basar, Ahmet Ozan; Sasmazel, Hilal TurkogluIn this study, a natural antibacterial substance chitosan was coated with/without potassium sorbate (KS) (0.8% (w/w) of KS, 8% (w/v) chitosan) onto the polypropylene (PP) film by using electrospinning technique to obtain novel antibacterial composite materials for various applications such as wound dressing, tissue engineering, drug delivery and food packaging. Atmospheric pressure plasma surface treatment was applied onto polypropylene films in order to increase its wettability thus enhancing the adhesion capacity of the films and the optimum CA value was determined as 42.75 +/- 0.80 degrees. Scanning Electron Microscope (SEM) and X-ray Photoelectron Spectroscopy (XPS) analyses were realized to observe the morphological changes and chemical properties of the samples, respectively. Contact angle measurements, tensile testing, oxygen and water vapor transmission rate analyses were performed to obtain wettability values, mechanical properties and WVTRs, respectively. The WVTR was increased by plasma treatment and addition of KS (from 14.264 +/- 0.214% to 21.020 +/- 0.659%). The desired antibacterial performance of the samples was assessed with Staphylococcus aureus and Escherichia coli by inhibition ratio calculation and disc diffusion assay. The highest inhibition ratios were found as 64% for S. aureus and 92% for E. coli for plasma-treated CS-KS-PP films.Correction Influence of Water/O2 Plasma Treatment on Cellular Responses of Pcl and Pet Surfaces (vol 21, Pg 123, 2011)(Ios Press, 2011) Sasmazel, Hilal Turkoglu; Aday, Sezin; Manolache, Sorin; Gumusderelioglu, Menemse[No Abstract Available]Article Citation - WoS: 6Citation - Scopus: 6A Drug-Eluting Nanofibrous Hyaluronic Acid-Keratin Mat for Diabetic Wound Dressing(Springernature, 2022) Su, Sena; Bedir, Tuba; Kalkandelen, Cevriye; Sasmazel, Hilal Turkoglu; Basar, Ahmet Ozan; Chen, Jing; Gunduz, OguzhanDiabetes mellitus is a chronic metabolic disease associated with long-term multisystem complications, among which are non-healing diabetic foot ulcers (DFUs). Electrospinning is a sophisticated technique for the preparation of polymeric nanofibers impregnated with drugs for wound healing, burns, and diabetic ulcers. This study describes the fabrication and characterization of a novel drug-eluting dressing made of core-shell structured hyaluronic acid (HA)-keratin (KR)-polyethylene oxide (PEO) and polycaprolactone (PCL) nanofibers to treat diabetic wounds. The core-shell nanofibers produced by the emulsion electrospinning technique provide loading of metformin hydrochloride (MH), HA, and KR in the core of nanofibers, which in return improves the sustained long term release of the drug and prolongs the bioactivity. Morphological and chemical properties of the fibers were examined by SEM, FTIR, and XRD studies. It was observed that the fibers which contain HA and KR showed thin fiber structure, greater swelling capacity, fast degradation and increased cumulative drug release amount than neat emulsion fibers due to the hydrophilic nature of HA and KR. MH showed a sustained release from all fiber samples over 20 days and followed the first-order and Higuchi model kinetics and Fickian diffusion mechanism according to kinetic analysis results. In vitro cell culture studies showed that the developed mats exhibited enhanced biocompatibility performance with HA and KR incorporation. The results show that HA and KR-based emulsion electrospun fiber mats are potentially useful new nanofiber-based biomaterials in their use as drug carriers to treat diabetic wounds.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: 22Citation - Scopus: 24Mechanical and Biological Properties of Al2o3< and Tio2 Co-Doped Zirconia Ceramics(Elsevier Sci Ltd, 2017) Agac, Ozlem; Gozutok, Melike; Sasmazel, Hilal Turkoglu; Ozturk, Abdullah; Park, JongeeVarious amounts (ranging from 0 to 2 wt%) of TiO2 and Al2O3 were mono and co-doped to tetragonal zirconia ceramic containing 3 mol% yttria (3Y-TZP) by mechanical ball milling. Powders were compacted by uniaxial pressing at a pressure of 23 MPa. The compacts were pressureless sintered at 1450 degrees C for 2 h. Density, hardness, fracture toughness, and cell attachment of the co-doped 3Y-TZP ceramics were measured with respect to dopant addition to determine the effects of the kind and amount of dopants on the properties. The results show that density decreased gradually as the amount of dopant was increased. The mechanical properties showed the maximum value when 0.5 wt% TiO2 and 1.0 wt% Al2O3 were co-doped to 3Y-TZP. Crystalline phase formation and microstructural morphology were investigated by XRD and SEM analyses to explain the variations in the properties. Co-doping of TiO2 and Al2O3 to 3Y-TZP did not have an influence on the phases present, but decreased the grain size. The co-doping also affected the cell attachment and the growth on the surface of the zirconia ceramics.Article Citation - WoS: 25Citation - Scopus: 24Preparation of Electrospun Pcl-Based Scaffolds by Mono/Multi-functionalized Go(Iop Publishing Ltd, 2019) Basar, Ahmet Ozan; Sadhu, Veera; Sasmazel, Hilal TurkogluIn the present study, sythetic biodegradable polymer poly(epsilon-caprolactone) (PCL) and graphene oxide (GO) were combined together to prepare 3D, composite tissue scaffolds (PCL/GO scaffolds) by using electrospinning technique. Also, the influence of Gly-Arg-Gly-Asp-Ser-Pro (GRGDSP) and/or thiophene (Th) modified GO on the composite PCL/GO mats (PCL/GO, PCL/GO-GRGDSP, PCL/ GO-Th, PCL/GO-GRGDSP-Th) was further investigated. Characteristic examinations of the scaffolds were carried out by scanning electron microscope (SEM), contact angle (CA) measurements, x-ray photoelectron spectroscopy, TGA, electrical conductivity tests, phosphate buffer saline absorption and shrinkage tests and mechanical tests. All of the scaffolds were exhibited suitable bead free and uniform morphology according to SEM images. With the addition of GO, better hydrophilicity and a slight CA decrease (similar to 5 degrees) for the PCL/GO scaffolds were observed. Mechanical properties were reinforced drastically with the addition and well-dispersion of GO into PCL matrix. The incorporation of PCL and GO exhibited enhanced electrical conductivity and the highest value was found for PCL/GO-GRGDSP-Th (2%) as 15.06 mu S cm(-1). The MG-63 osteoblast cell culture studies (MTT assay, ALP activity, Alizarin-Red staining, fluorescence and SEM analyses) showed that PCL/GO-GRGDSP-Th (1%) scaffolds exhibited the highest biocompatibility performance (1.87 fold MTT absorbance value comparing with neat PCL) due to the advanced properties of GO and the biological interfaces.Article Citation - WoS: 13Citation - Scopus: 14Core/Shell Glycine-Polyvinyl Alcohol/Polycaprolactone Nanofibrous Membrane Intended for Guided Bone Regeneration: Development and Characterization(Mdpi, 2021) Alazzawi, Marwa; Alsahib, Nabeel Kadim Abid; Sasmazel, Hilal TurkogluGlycine (Gly), which is the simplest amino acid, induces the inflammation response and enhances bone mass density, and particularly its beta polymorph has superior mechanical and piezoelectric properties. Therefore, electrospinning of Gly with any polymer, including polyvinyl alcohol (PVA), has a great potential in biomedical applications, such as guided bone regeneration (GBR) application. However, their application is limited due to a fast degradation rate and undesirable mechanical and physical properties. Therefore, encapsulation of Gly and PVA fiber within a poly(epsilon-caprolactone) (PCL) shell provides a slower degradation rate and improves the mechanical, chemical, and physical properties. A membrane intended for GBR application is a barrier membrane used to guide alveolar bone regeneration by preventing fast-proliferating cells from growing into the bone defect site. In the present work, a core/shell nanofibrous membrane, composed of PCL as shell and PVA:Gly as core, was developed utilizing the coaxial electrospinning technique and characterized morphologically, mechanically, physically, chemically, and thermally. Moreover, the characterization results of the core/shell membrane were compared to monolithic electrospun PCL, PVA, and PVA:Gly fibrous membranes. The results showed that the core-shell membrane appears to be a good candidate for GBR application with a nano-scale fiber of 412 +/- 82 nm and microscale pore size of 6.803 +/- 0.035 mu m. Moreover, the wettability of 47.4 +/- 2.2 degrees contact angle (C.A) and mechanical properties of 135 +/- 3.05 MPa average modulus of elasticity, 4.57 +/- 0.04 MPa average ultimate tensile stress (UTS), and 39.43% +/- 0.58% average elongation at break are desirable and suitable for GBR application. Furthermore, the X-ray diffraction (XRD) and transmission electron microscopy (TEM) results exhibited the formation of beta-Gly.Article 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 - 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.
