Şaşmazel, Hilal Türkoğlu
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Name Variants
S.,Hilal Turkoglu
Sasmazel, Hilal Tuerkoglu
Sasmazel, Hilal Turkoglu
H. T. Şaşmazel
Turkoglu Sasmazel H.
Sasmazel,H.T.
Şaşmazel,H.T.
Hilal Türkoğlu, Şaşmazel
H., Sasmazel
Şasmazel H.
S., Hilal Turkoglu
Ş.,Hilal Türkoğlu
Ş., Hilal Türkoğlu
Turkoğlu Şaşmazel H.
Hilal Turkoglu, Sasmazel
H.T.Sasmazel
H.T.Şaşmazel
Sasmazel H.
Sasmazel, H. T.
Türkoglu, H
Turkoglu, Hilal
Sasmazel, H. Turkoglu
Sasmazel, Hilal T.
H. T. Sasmazel
Şaşmazel, Hilal Türkoğlu
H.,Şaşmazel
Şaşmazel H.
Sasmazel, H. Tuerkodlu
Türkoǧlu Şaşmazel,H.
Şaşmazel, Hilal
Sasmazel, Hilal Tuerkoglu
Sasmazel, Hilal Turkoglu
H. T. Şaşmazel
Turkoglu Sasmazel H.
Sasmazel,H.T.
Şaşmazel,H.T.
Hilal Türkoğlu, Şaşmazel
H., Sasmazel
Şasmazel H.
S., Hilal Turkoglu
Ş.,Hilal Türkoğlu
Ş., Hilal Türkoğlu
Turkoğlu Şaşmazel H.
Hilal Turkoglu, Sasmazel
H.T.Sasmazel
H.T.Şaşmazel
Sasmazel H.
Sasmazel, H. T.
Türkoglu, H
Turkoglu, Hilal
Sasmazel, H. Turkoglu
Sasmazel, Hilal T.
H. T. Sasmazel
Şaşmazel, Hilal Türkoğlu
H.,Şaşmazel
Şaşmazel H.
Sasmazel, H. Tuerkodlu
Türkoǧlu Şaşmazel,H.
Şaşmazel, Hilal
Job Title
Profesor Doktor
Email Address
hilal.sasmazel@atilim.edu.tr
ORCID ID
Scopus Author ID
Turkish CoHE Profile ID
Google Scholar ID
WoS Researcher ID
Scholarly Output
52
Articles
33
Citation Count
750
Supervised Theses
9
49 results
Scholarly Output Search Results
Now showing 1 - 10 of 49
Article Citation Count: 51Atmospheric plasma surface modifications of electrospun PCL/chitosan/PCL hybrid scaffolds by nozzle type plasma jets for usage of cell cultivation(Elsevier Science Bv, 2016) Surucu, Seda; Masur, Kai; Sasmazel, Hilal Turkoglu; Von Woedtke, Thomas; Weltmann, Klaus Dieter; Metallurgical and Materials EngineeringThis paper reports Ar gas, Ar + O-2, Ar + O-2 + N-2 gas mixtures and dry air plasma modifications by atmospheric pressure argon driven kINPen and air driven Diener (PlasmaBeam) plasma jets to alter surface properties of three dimensional (3D), electrospun PCL/Chitosan/PCL layer by layer hybrid scaffolds to improve human fibroblast (MRC5) cell attachment and growth. The characterizations of the samples were done by contact angle (CA) measurements, scanning electron microscopy (SEM), X-Ray Photoelectron spectroscopy (XPS) analysis. The results showed that the plasma modification carried out under dry air and Ar + O-2 + N-2 gas mixtures were altered effectively the nanotopography and the functionality of the material surfaces. It was found that the samples treated with Ar + O-2 + N-2 gas mixtures for 1 min and dry air for 9 min have better hydrophilicity 78.9 degrees + 1.0 and 75.6 degrees + 0.1, respectively compared to the untreated samples (126.5 degrees). Biocompatibility performance of the scaffolds was determined with alamarBlue (aB) assay and MTT assay methods, Giemsa staining, fluorescence microscope, confocal laser scanning microscope (CLSM) and scanning electron microscope (SEM) analyses. The results showed that plasma treated samples increased the hydrophilicity and oxygen functionality and topography of the surfaces significantly, thus affecting the cell viability and proliferation on/within scaffolds. (C) 2016 Elsevier B.V. All rights reserved.Article Citation Count: 15Macroporous silicone biomaterials with modified surface chemistry: Production and characterization(Sage Publications Ltd, 2012) Gencer, Zeynep A.; Odabas, Sedat; Sasmazel, Hilal T.; Piskin, Erhan; Metallurgical and Materials EngineeringPorous and bioactive silicone biomaterials were developed for soft and cartilage tissue repair. A protocol, using compression molding, salt extraction, and supercritical carbon dioxide treatments, was used to obtain disk-shaped materials with specific pore sizes and morphologies by changing the process conditions. Highly open/interconnected macroporous silicone matrices, with an average pore size of 250-300 mu m and porosities in the range of 60%-70%, were obtained by the extracting the NaCl particles. Subsequent treatment with supercritical carbon dioxide slightly decreased the average pore size but increased the porosity to 80%. The supercritical carbon dioxide treatment effectively removed the entrapped salt crystals from the silicone matrix that improved interconnectivity. The compression modulus decreased, while the compression strength was increased using this technique. The surfaces and pores of the silicone materials were modified by silanization to provide primary amine groups for cell attachment, proliferation, migration, and three-dimensional growth of model L929 fibroblast cells.Article Citation Count: 0Development of Electrospun WE43 Magnesium Alloy-Like Compound(Amer Scientific Publishers, 2020) Ozkan, Ozan; Sasmazel, Hilal Turkoglu; Biskin, Erhan; Metallurgical and Materials EngineeringMetallic 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 Count: 15Development of Poly(vinyl alcohol) (PVA)/Reduced Graphene Oxide (rGO) Electrospun Mats(Amer Scientific Publishers, 2019) Gozutok, Melike; Sadhu, Veera; Sasmazel, Hilal Turkoglu; Metallurgical and Materials EngineeringIn 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.Article Citation Count: 16Preparation of electrospun PCL-based scaffolds by mono/multi-functionalized GO(Iop Publishing Ltd, 2019) Basar, Ahmet Ozan; Sadhu, Veera; Sasmazel, Hilal Turkoglu; Metallurgical and Materials EngineeringIn 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 Count: 8Core/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 Turkoglu; Metallurgical and Materials EngineeringGlycine (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 Count: 19Antibacterial Performance of PCL-Chitosan Core-Shell Scaffolds(Amer Scientific Publishers, 2018) Ozkan, Ozan; Sasmazel, Hilal Turkoglu; Metallurgical and Materials EngineeringIn this study, antibacterial performance of the coaxially electrospun Poly-epsilon-caprolactone (PCL)-chitosan core-shell scaffolds developed, optimized and identified physically and chemically in our previous study, were evaluated for the suitability in wound healing applications. The aim of utilizing a core-shell fibrous scaffold with PCL as core and chitosan as shell was to combine natural biocompatibility, biodegradability and antibacterial properties of chitosan with mechanical properties and resistance to enzymatic degradation of PCL. The scaffolds were prepared with the optimized parameters, obtained from our previous study. Thickness and contact angle measurements as well as Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM) analyses confirmed repeated fabrication of PCL-chitosan core-shell scaffolds. In this study, assays specific to wound dressing materials, such as water vapor transmission rate (WVTR), in vitro degradability and antibacterial tests were carried out. WVTR value of PCL-chitosan core-shell scaffolds was higher (2315 +/- 3.4 g/m(2).day) compared to single PCL scaffolds (1654 +/- 3.2 g/m(2).day) due to the higher inter-fiber pore size. Additionally, in vitro degradability assays showed that the susceptibility of chitosan to enzymatic degradation can be significantly improved by hybridization with more resistant PCL while still keeping the scaffold to be considered as biodegradable. Finally, inhibition ratio and inhibition zone measurements showed that the PCL-chitosan core-shell polymeric scaffolds had significant antibacterial performance (52.860 +/- 2.298% and 49.333 +/- 0.719% inhibition ratios; 13.975 +/- 0.124 mm and 12.117 +/- 0.133 mm clear inhibition zones, against E. coli and S. aureus, respectively), close to the native chitosan. Therefore, the developed scaffolds can be considered as suitable candidates for biodegradable wound dressing applications.Article Citation Count: 0Advanced 3D printed bone scaffolds with sodium alginate/Tri-calcium phosphate/probiotic bacterial hydroxyapatite: Enhanced mechanical and biocompatible properties for bone tissue engineering(Elsevier Sci Ltd, 2024) Nouri, Sabereh; Emtiazi, Giti; Ulag, Songul; Gunduz, Oguzhan; Koyuncu, Ayse Ceren Calikoglu; Roghanian, Rasoul; Sasmazel, Hilal Turkoglu; Metallurgical and Materials EngineeringIntroduction: The increasing prevalence of severe bone diseases, such as osteoporosis and critical bone defects, necessitates the development of more effective bone substitutes. This study addresses this need by investigating 3D-printed bone scaffolds composed of sodium alginate and tricalcium phosphate, enhanced with three distinct types of hydroxyapatite (HA): bovine-derived HA, commercially available HA, and HA enriched with probiotic bacteria. We aim to evaluate the performance of these scaffolds in terms of mechanical strength, biocompatibility, and their ability to support bone regeneration. Methods: The scaffolds were analyzed through various tests, including X-ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), Differential Scanning Calorimetry (DSC) to characterization. Scanning Electron Microscopy (SEM) was used to examine pore structure, while swelling and degradation tests evaluated the scaffold's stability. Compression testing determined mechanical strength, and in vitro cell culture assays assessed cell proliferation, osteogenic differentiation, and biomineralization. Results: SEM results indicated that 3D scaffolds with probiotic bacterial HA had the desired 472 mu m pore size. These scaffolds demonstrated a strain of 29.26 % and a compressive strength of 10 MPa, meeting the mechanical standards of human trabecular bone. Cell culture studies revealed enhanced cell proliferation by 50 %, osteogenic differentiation with 15.3 U/mg ALP activity, and 1.22-fold biomineralization, suggesting they are highly biocompatible and promote bone growth. Conclusion: Probiotic bacterial HA scaffolds exhibit ideal properties and biocompatibility, enhancing bone regeneration and serving as an ideal alternative to chemical types.Article Citation Count: 5Dielectric barrier discharge and jet type plasma surface modifications of hybrid polymeric poly (ε-caprolactone)/chitosan scaffolds(Sage Publications Ltd, 2018) Ozkan, Ozan; Sasmazel, Hilal Turkoglu; Metallurgical and Materials EngineeringIn this study, dry air plasma jet and dielectric barrier discharge Ar+O-2 or Ar+N-2 plasma modifications and their effects on wettability, topography, functionality and biological efficiency of the hybrid polymeric poly (epsilon-caprolactone)/chitosan scaffolds were reported. The samples treated with Ar+O-2 dielectric barrier discharge plasma (80 sccm O-2 flow rate, 3-min treatment) or with dry air plasma jet (15-cm nozzle-sample distance, 13-min treatment) had the closest wettability (49.11 +/- 1.83 and 53.60 +/- 0.95, respectively) to the commercial tissue culture polystyrene used for cell cultivation. Scanning electron microscopy images and X-ray photoelectron spectrometry analysis showed increase in topographical roughness and OH/NH2 functionality, respectively. Increased fluid uptake capacity for the scaffolds treated with Ar+O-2 dielectric barrier discharge plasma (73.60%+/- 1.78) and dry air plasma jet (72.48%+/- 0.75) were also noted. Finally, initial cell attachment as well as seven-day cell viability, growth and proliferation performances were found to be significantly better for both plasma treated scaffolds than for untreated scaffolds.Conference Object Citation Count: 0Impact of Nanotopography and/or Functional Groups on Periodontal Ligament Cell Growth(Springer, 2010) Sasmazel, Hilal Turkoglu; Manolache, S.; GumusderlIoglu, M.; Metallurgical and Materials EngineeringThe main purpose of this contribution was to obtain COOH functionalities and/or nanotopographic changes on the surface of 3D, non-woven polyester fabric (NWPF) discs (12.5 mm in diameter) by using low pressure water/O-2 plasma assisted treatments. The prepared discs were characterized by various methods after the plasma treatment. Periodontal ligament (PDL) fibroblasts were used in cell culture studies. The cell culture results showed that plasma treated 3D NWPF discs are favorable for PDL cell spreading, growth and viability due to the presence of functional groups and/or the nanotopography of their surfaces.
