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Article Citation - WoS: 35Citation - Scopus: 45Study on the Cytocompatibility, Mechanical and Antimicrobial Properties of 3d Printed Composite Scaffolds Based on Pva/ Gold Nanoparticles (aunp)/ Ampicillin (amp) for Bone Tissue Engineering(Elsevier, 2021) Topsakal, Aysenur; Midha, Swati; Yuca, Esra; Tukay, Ari; Sasmazel, Hilal Turkoglu; Kalaskar, Deepak M.; Gunduz, OguzhanOver 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.Article Citation - WoS: 18Citation - Scopus: 19Effects of Nozzle Type Atmospheric Dry Air Plasma on L929 Fibroblast Cells Hybrid Poly (ε-caprolactone)/Chitosan (ε-Caprolactone) Scaffolds Interactions(Soc Bioscience Bioengineering Japan, 2016) Ozkan, Ozan; Sasmazel, Hilal TurkogluIn 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.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 Design and Fabrication of Dual-Layered PCL/PEG Theranostic Platforms Using 3D Melt Electrowriting for Targeted Delivery and Post-Treatment Monitoring(Springer, 2025) Ege, Zeynep Ruya; Enguven, Gozde; Ege, Hasan; Durukan, Barkan Kagan; Sasmazel, Hilal Turkoglu; Gunduz, OguzhanAdvanced pancreatic tumors remain highly resistant to treatment due to their dense stromal environment and poor vascularization, which limit drug penetration and efficacy. Even after surgical resection, the high recurrence rate frequently leads to poor prognosis and mortality. To address these challenges, we developed solvent-free three-dimensional (3D) melt electrowritten (MEW) theranostic microfiber patches composed of poly(epsilon-caprolactone) (PCL) and polyethylene glycol (PEG). The patches were designed as dual-layered, 10-layer structures, with gemcitabine (GEM) loaded in the bottom five layers for localized chemotherapy to suppress tumor recurrence, and indocyanine green (ICG) incorporated in the top five layers to enable fluorescence-based post-surgical monitoring. Following fabrication, the patches were characterized both materially and in vitro, with GEM loaded at 100, 250, or 500 mu g/ml. PEG incorporation improved patch flexibility, facilitating the implantation process. In vitro release analysis demonstrated an initial burst followed by sustained, pH-responsive GEM release (similar to 70% at pH 4.0 and similar to 30% at pH 7.4 for 500 mu g/mL GEM at 168 h), while ICG release reached similar to 25% (pH 7.4) and similar to 10% (pH 4.0). GEM-loaded patches significantly reduced Capan-1 cell viability in a dose- and time-dependent manner, achieving >= 50% reduction at 72 h with 500 mu g/mL. Importantly, ICG incorporation did not impair GEM cytotoxicity; confocal imaging confirmed ICG internalization in viable cells and showed a decline in ICG-positive cells with increasing GEM dose, supporting the potential for concurrent therapy and monitoring. Thus, the theranostic patches enable localized, pH-responsive GEM delivery with integrated ICG-based fluorescence imaging, achieving significant cytotoxicity against pancreatic cancer cells while providing a platform for post-surgical surveillance. This solvent-free, layer-addressable approach represents a promising strategy for personalized, locally implantable theranostic systems in pancreatic cancer treatment.Article Citation - WoS: 9Citation - Scopus: 9Dielectric Barrier Discharge and Jet Type Plasma Surface Modifications of Hybrid Polymeric Poly (ε-caprolactone)/Chitosan Scaffolds(Sage Publications Ltd, 2018) Ozkan, Ozan; Sasmazel, Hilal TurkogluIn 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.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: 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: 4Citation - Scopus: 5In Vitro Evaluation of Tooth-Colored Yttria Stabilized Zirconia Ceramics(Taylor & Francis Ltd, 2021) Akarsu, Melis Kaplan; Basar, Ahmet Ozan; Sasmazel, Hilal Turkoglu; Park, Jongee; Ozturk, AbdullahEffects of MoCl3 and NiCl2, originally incorporated as coloring agent, on the cellular response of 3 mol% yttria stabilized zirconia (3Y-TZP) ceramics was investigated. MoCl3 and NiCl2-MoCl3 incorporated, tooth-colored 3Y-TZP ceramics were produced through cold isostatic pressing at 100 MPa followed by pressureless sintering at 1450 degrees C for 2 h. Aging was performed on the sintered ceramics using distilled water in a reactor at 134 degrees C at 2.3 bar pressure for 2 h. The phases developed during different stages of processing were identified by X-ray diffraction (XRD) analysis. In vitro cell culture studies were carried out using L929 fibroblast cell line. The cell viability and proliferation studies revealed that none of the specimens showed cytotoxicity with respect to coloring. Confocal laser scanning microscope (CLSM) analyses suggested that all of the specimens exhibited good in vitro cytocompatibility. Enhancement in cell attachment, adhesion, and proliferation was observed in all specimens via scanning electron microscope (SEM) analysis. Although the coloring process did not improve the proliferation performance of the aged specimens, the incorporation of transition metals enhanced the in vitro performance of 3Y-TZP ceramics.Article Citation - WoS: 10Citation - Scopus: 11Functionalization of Nonwoven Pet Fabrics by Water/O2< Plasma for Biomolecule Mediated Cell Cultivation(Wiley-v C H verlag Gmbh, 2010) Sasmazel, Hilal Turkoglu; Manolache, Sorin; Gumusderelioglu, MenemseThe 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.
