Browsing by Author "Şaşmazel, Hilal Türkoğlu"

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Citation Count: 0
Advanced 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 Engineering
Introduction: 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.
Citation Count: 19
Antibacterial Performance of PCL-Chitosan Core-Shell Scaffolds
(Amer Scientific Publishers, 2018) Ozkan, Ozan; Sasmazel, Hilal Turkoglu; Metallurgical and Materials Engineering
In 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.
Citation Count: 51
Atmospheric 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 Engineering
This 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.
Citation Count: 36
Atmospheric Pressure Plasma Surface Treatment of Polymers and Influence on Cell Cultivation
(Mdpi, 2021) Sasmazel, Hilal Turkoglu; Alazzawi, Marwa; Alsahib, Nabeel Kadim Abid; Metallurgical and Materials Engineering
Atmospheric 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.
Coating of titanium (TiAl6V4)) alloy by electrospun poly (ε-caprolactone) (PCL)
(2020) Gelal, Hasan Mohammed Alı Abdullah Al; Şaşmazel, Hilal Türkoğlu; Davut, Kemal; Metallurgical and Materials Engineering
Çalışmanın amacı, elekroeğirme mekanizması kullanılarak poli (ε-kaprolakton) (PCL) ile kaplanmış titanyum alaşımı TiAl6V4'ten oluşan bir biyomateryal implant üretmektir. Ayrıca, titanyum alaşımı için yüzey işleminin kaplama üzerindeki etkisi de incelenirken, kaplama kalınlığı bir mikrometre kullanılarak belirlenmiştir. Örneklerin morfolojik karakterizasyonu Taramalı Elektron Mikroskopisi (SEM) kullanılarak gerçekleştirilmiştir. Yüzey ıslanabilirliği, temas açısı (CA) kullanılarak tayin edilmiştir ve titanyum alaşımlı mikroyapının optik mikrografları, optik mikroskopi kullanılarak elde edilmiştir. Substratlarda kompozisyon ve elementlerin tayini Enerji dağılımlı spektroskopisi (EDS) ile yapılmıştır. Yüzey morfolojisinin daha detaylı nicel analizi ve implantların yüzeyindeki pürüzlülüğü değerlendirmek için AFM ve pürüzlülük ölçümleri kullanılmıştır. PCL'nin TiAl6V4'e yapışmasını belirlemek için yapışma testi yapılmıştır. EDS ile sonuçlarına göre elde edilen örneklerin işlendikten sonra diğer elementlerden arınmış olduğu görülmüştür. Optik mikroskopi, alaşımların ön işlemden geçirilmesinden sonra optik mikrograflar vasıtasıyla mikro yapıdaki değişiklikleri gözlemlemek için kullanılmıştır. SEM ile taşlama, parlatma ve dağlamadan sonra yüzey morfolojisindeki değişim de kaydedilmiştir. Pürüzlülük ölçümleri, 3 mikron parlatma TiAl6V4 numunesinde 0.005 mikrondan, 120 öğütme TiAl6V4 numunesinde 0.56 mikrona kadar olan ortalama pürüzlülük değerlerini kantitatif olarak göstermiştir. Ölçümlerden sonra, kaplamanın kalınlığı 0.01 mm olarak belirlenmiştir. Temas açısı ölçümleri sonucunda en iyi hidrofilikliğe sahip numunenin 58.63° temas açısı ile PCL ile kaplanmış kazınmış alaşım olduğu görüşmüştür. Ayrıca yapışma testi, kaplama yapışması için en iyi iki adayın kazınmış ve 1200 öğütme numuneleri olduğunu göstermiştir: kaplamanın %99'undan fazlası, bandın çıkarılmasından sonra kaplamadan çıkmaz. Anahtar kelimeler: Electrospinning, TiAl6V4 alloy, Poly (𝜀-caprolactone)
Citation Count: 63
Coaxial and emulsion electrospinning of extracted hyaluronic acid and keratin based nanofibers for wound healing applications
(Pergamon-elsevier Science Ltd, 2021) Su, Sena; Bedir, Tuba; Kalkandelen, Cevriye; Basar, Ahmet Ozan; Sasmazel, Hilal Turkoglu; Ustundag, Cem Bulent; Gunduz, Oguzhan; Metallurgical and Materials Engineering
Novel composites based on poly(epsilon-caprolactone)/polyethylene oxide loaded with hyaluronic acid(HA) and keratin(KR) were produced separately using emulsion and coaxial electrospinning methods. HA and KR were extracted from animal sources, characterized and loaded into coaxial fiber structures as bioactive agents, separately and together. Morphological, chemical, thermal, and mechanical characteristics of the fibers were investigated. According to the SEM results, diameters of smooth and beadless fibers fabricated via emulsion method were at nanoscale (sub-micron) while fibers of coaxial method were at micro scale. Benefitted electrospinning techniques demonstrated that hydrophobic and hydrophilic polymers can be advantageously combined. Core polymer specific FT-IR bands were not visible, their presence was proven with DSC analysis which confirms core-shell morphology of the fibers. In vitro studies exhibited spun mats did not have any cytotoxic effects and the HA and KR incorporated into the fiber structure synergistically increased cell viability and cell proliferation. This study demonstrated that the electrospun fibers containing HA and KR fabricated by both emulsion and coaxial methods can be efficient for wound healing applications.
Citation Count: 27
Comparison of cellular proliferation on dense and porous PCL scaffolds
(Ios Press, 2008) Sasmazel, Hilal Tuerkoglu; Gumusderelioglu, Menemse; Gurpinar, Aylin; Onur, Mehmet Ali; Metallurgical and Materials Engineering
In this contribution, PCL (poly-e caprolactone) scaffolds were prepared by solvent-casting/particle-leaching technique in the presence of two pore formers, PEG(4000) or sucrose molecules in different quantities (0, 10, 20, 30, 40, 50, 55 w/w% PEG(4000)/PCL; 10, 20 w/w% Sucrose/ PCL). The surface and bulk properties of the resulting scaffolds were studied by SEM, DSC and FTIR. SEM photographs showed that, macroporosity was obtained in the PCL structures prepared with sucrose crystals while microporous structure was obtained in the presence of PEG(4000) molecules. Average pore diameters calculated from SEM photographs were 40.1 and 191.2 mu m for 40% PEG(4000)/PCL and 10% Sucrose/PCL scaffolds, respectively. The DSC and FTIR results confirmed that there is no any interaction between pore formers and PCL during structural formation, and both pore formers, PEG(4000) and sucrose, remained independently in the scaffolds. L929 mouse fibroblast cells were seeded onto PCL structures and maintained during 7 days to evaluate cell proliferation. Cell culture results showed that, 10% Sucrose/ PCL scaffold was the most promising substrate for L929 cell growth due to 3-D architecture and macroporous structure of the scaffold.
Citation Count: 8
Core/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 Engineering
Glycine (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.
Citation Count: 19
DBD atmospheric plasma-modified, electrospun, layer-by-layer polymeric scaffolds for L929 fibroblast cell cultivation
(Taylor & Francis Ltd, 2016) Surucu, Seda; Sasmazel, Hilal Turkoglu; Metallurgical and Materials Engineering
This paper reported a study related to atmospheric pressure dielectric barrier discharge (DBD) Ar+O-2 and Ar+N-2 plasma modifications to alter surface properties of 3D PCL/Chitosan/PCL layer-by-layer hybrid scaffolds and to improve mouse fibroblast (L929 ATCC CCL-1) cell attachment, proliferation, and growth. The scaffolds were fabricated using electrospinning technique and each layer was electrospun sequentially on top of the other. The surface modifications were performed with an atmospheric pressure DBD plasma under different gas flow rates (50, 60, 70, 80, 90, and 100sccm) and for different modification times (0.5-7min), and then the chemical and topographical characterizations of the modified samples were done by contact angle (CA) measurements, scanning electron microscopy (SEM), atomic force microscopy, and X-ray photoelectron spectroscopy. The samples modified with Ar+O-2 plasma for 1min under 70cm(3)/min O-2 flow rate (71.077 degrees +/- 3.578) showed a 18.83% decrease compare to unmodified samples' CA value (84.463 degrees +/- 3.864). Comparing with unmodified samples, the average fiber diameter values for plasma-modified samples by Ar+O-2 (1min 70sccm) and Ar+N-2 (40s 70sccm) increased 40.756 and 54.295%, respectively. Additionally, the average inter-fiber pore size values exhibited decrease of 37.699 and 48.463% for the same Ar+O-2 and Ar+N-2 plasma-modified samples, respectively, compare to unmodified samples. Biocompatibility performance was determined with MTT assay, fluorescence, Giemsa, and confocal imaging as well as SEM. The results showed that Ar+O-2-based plasma modification increased the hydrophilicity and oxygen functionality of the surface, thus affecting the cell viability and proliferation on/within scaffolds.
Citation Count: 9
Development of Antibacterial Composite Electrospun Chitosan-Coated Polypropylene Materials
(Amer Scientific Publishers, 2018) Gozutok, Melike; Basar, Ahmet Ozan; Sasmazel, Hilal Turkoglu; Metallurgical and Materials Engineering
In 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.
Citation Count: 78
Development of core-shell coaxially electrospun composite PCL/chitosan scaffolds
(Elsevier, 2016) Surucu, Seda; Sasmazel, Hilal Turkoglu; Metallurgical and Materials Engineering
This study was related to combining of synthetic Poly (epsilon-caprolactone) (PCL) and natural chitosan polymers to develop three dimensional (3D) PCL/chitosan core-shell scaffolds for tissue engineering applications. The scaffolds were fabricated with coaxial electrospinning technique and the characterizations of the samples were done by thickness and contact angle (CA) measurements, scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-Ray Photoelectron Spectroscopy (XPS) analyses, mechanical and PBS absorption and shrinkage tests. The average inter-fiber diameter values were calculated for PCL (0.717 +/- 0.001 mu m), chitosan (0.660 +/- 0.007 mu m) and PCL/chitosan core-shell scaffolds (0.412 +/- 0.003 mu m), also the average inter-fiber pore size values exhibited decreases of 66.91% and 61.90% for the PCL and chitosan scaffolds respectively, compared to PCL/chitosan core-shell ones. XPS analysis of the PCL/chitosan core-shell structures exhibited the characteristic peaks of PCL and chitosan polymers. The cell culture studies (MTT assay, Confocal Laser Scanning Microscope (CLSM) and SEM analyses) carried out with L929 ATCC CCL-1 mouse fibroblast cell line proved that the biocompatibility performance of the scaffolds. The obtained results showed that the created micro/nano fibrous structure of the PCL/chitosan core-shell scaffolds in this study increased the cell viability and proliferation on/within scaffolds. (C) 2016 Elsevier B.V. All rights reserved.
Citation Count: 0
Development of Electrospun WE43 Magnesium Alloy-Like Compound
(Amer Scientific Publishers, 2020) Ozkan, Ozan; Sasmazel, Hilal Turkoglu; Biskin, Erhan; Metallurgical and Materials Engineering
Metallic 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.
Citation Count: 15
Development 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 Engineering
In 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.
Citation Count: 5
Dielectric 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 Engineering
In 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.
Doku mühendisliği uygulamalarına yönelik elektriksel olarak iletken çekirdek-kabuk tipi eşeksenli elektroeğrilmiş PVA-PEDOT: PSS-KNT pHEMA kompozit fiber malzemenin geliştirilmesi
(2023) Çelen, Emrah; Şaşmazel, Hilal Türkoğlu; Metallurgical and Materials Engineering
Bu çalışmanın amacı eşeksenli elektroeğirme tekniği kullanılarak elektriksel olarak iletken PEDOT: PSS-KNT/pHEMA çekirdek-kabuk tipi fiberler üretmektir. Kalınlık, fiber çapı, por büyüklüğü, porozite yüzdesi, temas açısı, elektriksel iletkenlik ve mekanik özelliklerin belirlenmesi için pHEMA, PVA-PEDOT: PSS, PVA-KNT, PVA-PEDOT: PSS-CNT, pHEMA/PVA-PEDOT: PSS, pHEMA/PVA-KNT, pHEMA/PVA-PEDOT: PSS-KNT kompozit malzemeleri karakterize edilmiştir. SEM'den elde edilen görüntülere göre üretilmiş olan tüm malzemeler boncuksuz ve tekdüze yapılardır, ayrıca görüntüler göstermiştir ki pHEMA fiberlerin çapı 825±118 nm iken pHEMA/PVA-PEDOT: PSS-CNT fiberlerinin çapları 578±79 nanometredir. Buna ek olarak pHEMA'nın fiberlerarası por büyüklüğü 2.62 µm iken pHEMA/PVA-PEDOT: PSS-KNT malzemesindeki fiberlerarası por büyüklüğü 1.75 µm'dir. elde edilen malzemelerin çekirdek-kabuk yapısına sahip olduğu TEM görüntüleriyle kanıtlanmış ve iç ve dış çaplarının SEM sonuçlarıyla uyumlu olduğu belirtilmiştir. Temas açısı ölçümlerinde göstermiştir ki pHEMA, hidrofilik bir malzeme olup temas açısı 10.48±0.08'dir, buna ek olarak pHEMA/PVA-PEDOT: PSS-KNT benzer karakteristik göstermiş olup temas açısı 11.24±0.54 olarak belirlenmiştir. En yüksek elektrik iletkenliği PVA-PEDOT: PSS-KNT malzemesinde 14.27 µS/cm olarak ölçülmüş olup pHEMA/PVA-PEDOT: PSS-KNT'de daha düşük olup 10.58 14.27 µS/cm şeklinde belirlenmiştir. Son olarak mekanik testler gerçekleştirilmiş olup bu testler sonucunda en yüksek elastik modüle sahip örnek 8500 kPa ile PVA-PEDOT: PSS iken pHEMA 200 kPa, pHEMA/PVA-PEDOT: PSS-KNT ise 600 kPa elastik modüle sahiptir. TGA analizi sonuçlarına göre, pHEMA/PVA-PEDOT: PSS-CNT'nin pHEMA'dan daha yüksek bir bozunma sıcaklığı gerektirdiği gösterilmiştir. PVA-PEDOT: PSS-CNT'nin çekirdeğe eklenmesiyle pHEMA'nın ATR-FTIR spektrumunda hafif bir kayma gözlemlenmiş. Son olarak, L929 fibroblast hücre hattı kullanılarak hücre-malzeme etkileşimleri gözlemlenmiştir. Bu çalışma, koaksiyel elektrospun pHEMA/PVA-PEDOT: PSS-CNT çekirdek-kabuk liflerinin doku mühendisliği uygulamaları için umut verici bir aday olduğunu göstermektedir.
Citation Count: 5
A 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, Oguzhan; Metallurgical and Materials Engineering
Diabetes 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.
Citation Count: 0
Editorial: Biofabricated materials for tissue engineering
(Frontiers Media Sa, 2024) Sasmazel, Hilal Turkoglu; Gunduz, Oguzhan; Ramalingam, Murugan; Ulag, Songul; Metallurgical and Materials Engineering
[No Abstract Available]
Citation Count: 1
EFFECTS OF FUNCTIONAL GROUPS, BIOSIGNAL MOLECULES AND NANOTOPOGRAPHY ON CELLULAR PROLIFERATION
(Springer, 2009) Sasmazel, H. T.; Manolache, S.; Guemuesderelioglu, M.; Metallurgical and Materials Engineering
The aim Of this Study is the development of novel cell Support materials for fibroblast cell cultivation by using low-pressure plasma assisted treatment. Poly(epsilon-caprolactone) (PCL) membranes were prepared by solvent-casting technique. The plasma assisted treatment was focused oil generating a nano-topography and obtaining COOH functionalities oil the Surface of the membranes. The immobilization of biomolecules onto the PCL membranes was realized after the plasma treatment, The membranes prepared were characterized by various methods before and after the biomodification. L929 mouse fibroblasts were used for cell Culture evaluation. The prominent roles Of Surface nano-topography and carboxylic groups generated by the plasma in obtaining better cell growth on PCL Surfaces are highlighted in this study.
Citation Count: 18
Effects of nozzle type atmospheric dry air plasma on L929 fibroblast cells hybrid poly (ε-caprolactone)/chitosan/poly (ε-caprolactone) scaffolds interactions
(Soc Bioscience Bioengineering Japan, 2016) Ozkan, Ozan; Sasmazel, Hilal Turkoglu; Metallurgical and Materials Engineering
In the study presented here, in order to improve the surface functionality and topography of poly (epsilon-caprolactone) (PCL)/chitosan/PCL hybrid tissue scaffolds fabricated layer by layer with electrospinning technique, an atmospheric pressure nozzle type plasma surface modification was utilized. The optimization of the plasma process parameters was carried out by monitoring the changes in surface hydrophilicity by using contact angle measurements. SEM, AFM and XPS analyses were utilized to observe the changes in topographical and chemical properties of the modified surfaces. The results showed that applied plasma modification altered the nanotopography and the functionality of the surfaces of the scaffolds. The modification applied for 9 min from a distance of 17 cm was found to provide the possible contact angle value (75.163 +/- 0.083) closest to the target value which is the value of tissue culture polystyrene (TCPS) petri dishes (similar to 49.7 degrees), compared to the unmodified samples (84.46 +/- 3.86). In vitro cell culture was carried out by L929 mouse fibroblast cell line in order to examine the effects of plasma surface modification on cell material interactions. Standard MIT assay showed improved cell viability on/within modified scaffolds confirmed with the observations of the cell attachment and the morphology by means of SEM, fluorescence and confocal imaging. The experiments performed in the study proved the enhanced biocompatibility of the nozzle type dry air plasma modified scaffolds. (C) 2016, The Society for Biotechnology, Japan. All rights reserved.
Citation Count: 53
Electrospun Oxygen Scavenging Films of Poly(3-hydroxybutyrate) Containing Palladium Nanoparticles for Active Packaging Applications
(Mdpi, 2018) Cherpinski, Adriane; Gozutok, Melike; Sasmazel, Hilal Turkoglu; Torres-Giner, Sergio; Lagaron, Jose M.; Metallurgical and Materials Engineering
This paper reports on the development and characterization of oxygen scavenging films made of poly(3-hydroxybutyrate) (PHB) containing palladium nanoparticles (PdNPs) prepared by electrospinning followed by annealing treatment at 160 degrees C. The PdNPs were modified with the intention to optimize their dispersion and distribution in PHB by means of two different surfactants permitted for food contact applications, i.e., hexadecyltrimethylammonium bromide (CTAB) and tetraethyl orthosilicate (TEOS). Analysis of the morphology and characterization of the chemical, thermal, mechanical, and water and limonene vapor barrier properties and the oxygen scavenging capacity of the various PHB materials were carried out. From the results, it was seen that a better dispersion and distribution was obtained using CTAB as the dispersing aid. As a result, the PHB/PdNP nanocomposites containing CTAB provided also the best oxygen scavenging performance. These films offer a significant potential as new active coating or interlayer systems for application in the design of novel active food packaging structures.