1,720,979 research outputs found
Novel Hybrid Scaffolds for the Cultivation of Osteoblast Cells
No full textTurkoglu Sasmazel, Hilal/0000-0002-0254-4541In 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.Turkish Academy of Science (TUBA) L'Oreal; L'OrealThe author is greatly thankful to Turkish Academy of Science (TUBA) & L'Oreal for honoring this study with the award "Young Women in Science" in Materials Science in 2009. Her special thanks also go to L'Oreal for the precious financial support. The author also appreciates the invaluable contribution of AWAC (Academic Writing Advisory Center) to this study in linguistic terms
Hybrid Polymeric Scaffolds Prepared by Micro and Macro Approaches
No full textTurkoglu Sasmazel, Hilal/0000-0002-0254-4541; Ozkan, Ozan/0000-0002-9050-1583Polymeric scaffolds with complex porous structures were fabricated with two different polymers by combining three fabrication methods in three steps, in which, nonwoven poly(e-caprolactone) microfibers were obtained with electrospinning and immersed in solvent cast chitosan solution poured in Petri dish to fabricate hybrid polymers, and finally the combined structure was freeze-dried with two different predrying techniques to obtain macropores in the structure. The resulting hybrid polymeric mats were found to have both microfibers and macroporosity due to the electrospinning as well as freeze-drying processes, which resemble the natural extracellular matrix. The optimized scaffolds that predried in the incubator at 40 degrees C for 5 h and then freeze-dried for 24 h exhibited contact angle value of 68.93 +/- 2.18 degrees with 3.252 +/- 0.783 MPa Young's modulus and 0.260 +/- 0.002 MPa yield strength as well as 1.35-fold cell yield in MRC5 fibroblast cell culture, compared to the commercial tissue culture polystyrene. [GRAPHICS]
Study on the cytocompatibility, mechanical and antimicrobial properties of 3D printed composite scaffolds based on PVA/ Gold nanoparticles (AuNP)/ Ampicillin (AMP) for bone tissue engineering
No full textOver the years, gold nanoparticles (AuNP) have been widely used in several biomedical applications related to the diagnosis, drug delivery, bio-imaging, photo-thermal therapy and regenerative medicine, owing to their unique features such as surface plasmon resonance, fluorescence and easy surface functionality. Recent studies showed that gold nanoparticles display positive effect on osteogenic differentiation. In line with this effect, 3-Dimesional (3D) scaffolds that can be used in bone tissue were produced by exploiting the properties of gold nanoparticles that increase biocompatibility and support bone tissue development. In addition, ampicillin was added to the scaffolds containing gold nanoparticles as a model drug to improve its antimicrobial properties. The scaffolds were produced as composites of polyvinyl alcohol (PVA) main matrix as PVA, PVA/AuNP, PVA/Ampicillin (AMP) and PVA/AuNP/AMP. Scanning Electron Microscopy (SEM) Fourier Transform Infrared Spectroscopy (FTIR), tensile measurement tests, and in vitro applications of 3D scaffolds were performed. As depicted by SEM, scaffolds were produced at pore sizes appropriate for bone tissue regeneration. According to FTIR results, there was no modification observed in the AMP, PVA and gold nanoparticles due to mixing in the resultant scaffolds. In vitro results show that 3D printed composite scaffold based on PVA/AuNP/AMP are biocompatible, osteo-inductive and exhibit antimicrobial properties, compared to PVA scaffolds. This study has implications for addressing infections during orthopedic surgeries. The PVA-based gold nanoparticle 3D tissue scaffold study containing ampicillin covers a new study compared to other articles based on gold nanoparticles
Antibacterial Performance of Pcl-Chitosan Core-Shell Scaffolds
No full textOzkan, Ozan/0000-0002-9050-1583; Turkoglu Sasmazel, Hilal/0000-0002-0254-4541In 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.Scientific and Technological Research Council of Turkey (TUBITAK) [114M872]The authors would like to thank The Scientific and Technological Research Council of Turkey (TUBITAK) for the scientific and financial support (Project No: 114M872). The authors would also like to acknowledge the contribution of AWAC (Academic Writing Advisory Center) of Atilim University to this study in linguistic terms. The material and its fabrication procedures are patent pending (Turkish Patent Institute, Application No: 2015/17118)
Development of Electrospun We43 Magnesium Alloy-Like Compound
No full textOzkan, Ozan/0000-0002-9050-1583; Turkoglu Sasmazel, Hilal/0000-0002-0254-4541Metallic 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.Scientific and Technological Research Council of Turkey (TUBITAK) [117M177]The authors would like to thank The Scientific and Technological Research Council of Turkey (TUBITAK) for the scientific and financial support (Project No: 117M177). The authors would also like to acknowledge the contribution of AWAC (Academic Writing Advisory Center) of Atilim University to this study in linguistic terms
Impact of Nanotopography And/Or Functional Groups on Periodontal Ligament Cell Growth
No full textTurkoglu Sasmazel, Hilal/0000-0002-0254-4541The 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
Functionalization of Nonwoven Pet Fabrics by Water/O<sub>2< Plasma for Biomolecule Mediated Cell Cultivation
No full textTurkoglu Sasmazel, Hilal/0000-0002-0254-4541The main target of this study was to obtain COOH functionalities on the surface of 3D, nonwoven polyethylene terephthalate fabrics (NWPFs) by using low pressure water/O-2 plasma assisted treatment. The plasma treatments were performed in a cylindrical, capacitively coupled RF-plasma-reactor and then following steps were performed: in situ (oxalyl chloride vapors) gas/solid reaction to convert -OH functionalities into COCl groups; and hydrolysis under open laboratory conditions using air moisture for final-COOH functionalities. COOH and OH functionalities on the surfaces were detected quantitatively by fluorescent labeling techniques. The COOH-functionalized samples were biologically activated with insulin or heparin molecules by using spacer polyoxyethylene bis-amine (PEO). Successful immobilization was checked qualitatively using electron spectroscopy for chemical analysis (ESCA). The average amount of immobilized insulin and heparin onto NWPF surfaces were determined as 146.09 and 4.81 nmol.cm(-2), respectively. Our results showed that water/O-2 plasma assisted treatment worked very well for functionalization and biofunctionalization of 3D NWPF disks comparing with wet-chemistry methods. Cell culture experiments indicated that functionalization of NWPF disks and/or nanotopographies on the disk surfaces were effective on adhesion and proliferation of L929 mouse fibroblasts
Coaxial and emulsion electrospinning of extracted hyaluronic acid and keratin based nanofibers for wound healing applications
No full textNovel 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
Influence of Water/O2 Plasma Treatment on Cellular Responses of Pcl and Pet Surfaces (vol 21, Pg 123, 2011)
No full textAday, Sezin/0000-0003-4396-7812[No Abstract Available
Editorial: Biofabricated Materials for Tissue Engineering
Full text linkRamalingam, Murugan/0000-0001-6498-9792[No Abstract Available
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