Browsing by Author "Aksoy, Eda Ayse"

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Citation Count: 8
Gentamicin Loaded Β-Tricalcium Phosphate/Gelatin Composite Microspheres as Biodegradable Bone Fillers
(Wiley, 2012) Sezer, Umran Aydemir; Aydemir, Ümran; Aksoy, Eda Ayse; Durucan, Caner; Hasirci, Nesrin; Chemical Engineering
In this study, novel composite bone fillers with microspherical shape, biodegradable property, and antibacterial effect were designed and prepared. Various fillers with different beta-tricalcium phosphate (beta-TCP)/gelatin (G)/glutaraldeyde (GA) compositions were loaded with a model antibiotic, gentamicin. The effect of composition and preparation conditions on the release of gentamicin was investigated in in vitro conditions. Complete release were observed in 12 h for pure beta-TCP powder, and this period was extended up to 96 h as the gelatin content increased in the microspheres. Morphological and chemical structures of the microspheres, before and after the release studies, were investigated by scanning electron microscopy and Fourier transform infrared, respectively. Antibacterial activities were examined against Escherichia coli by using disc diffusion method and promising results were obtained. It is proposed that these novel beta-TCP/G/GA microspheres can be applied locally to prevent and/or eliminate infection that might occur around a defected region of hard tissue and supports the healing process. POLYM. COMPOS., 2012. (c) 2012 Society of Plastics Engineers
Citation Count: 18
Poly(ε-Caprolactone) Composite Scaffolds Loaded With Gentamicin-Containing Β-Tricalcium Phosphate/Gelatin Microspheres for Bone Tissue Engineering Applications
(Wiley, 2014) Sezer, Umran Aydemir; Aydemir, Ümran; Arslantunali, Damla; Aksoy, Eda Ayse; Hasirci, Vasif; Hasirci, Nesrin; Chemical Engineering
In this study, novel poly(epsilon-caprolactone) (PCL) composite scaffolds were prepared for bone tissue engineering applications, where gentamicin-loaded -tricalcium phosphate (-TCP)/gelatin microspheres were added to PCL. The effects of the amount of -TCP/gelatin microspheres added to the PCL scaffold on various properties, such as the gentamicin release rate, biodegradability, morphology, mechanical strength, and pore size distribution, were investigated. A higher amount of filler caused a reduction in the mechanical properties and an increase in the pore size and led to a faster release of gentamicin. Human osteosarcoma cells (Saos-2) were seeded on the prepared composite scaffolds, and the viability of cells having alkaline phosphatase (ALP) activity was observed for all of the scaffolds after 3 weeks of incubation. Cell proliferation and differentiation enhanced the mechanical strength of the scaffolds. Promising results were obtained for the development of bone cells on the prepared biocompatible, biodegradable, and antimicrobial composite scaffolds. (c) 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40110.
Citation Count: 15
Poly(ε-Caprolactone) Composites Containing Gentamicin-Loaded Β-Tricalcium Phosphate/Gelatin Microspheres as Bone Tissue Supports
(Wiley, 2013) Sezer, Umran Aydemir; Aydemir, Ümran; Aksoy, Eda Ayse; Hasirci, Vasif; Hasirci, Nesrin; Chemical Engineering
In this work, novel antibacterial composites were prepared by using poly(epsilon-caprolactone) (PCL) as the main matrix material, and gentamicin-loaded microspheres composed of beta-tricalcium phosphate (beta-TCP) and gelatin. The purpose is to use this biodegradable material as a support for bone tissue. This composite system is expected to enhance bone regeneration by the presence of beta-TCP and prevent a possible infection that might occur around the defected bone region by the release of gentamicin. The effects of the ratio of the beta-TCP/gelatin microspheres on the morphological, mechanical, and degradation properties of composite films as well as in vitro antibiotic release and antibacterial activities against Escherichia coli and Staphylococcus aureus were investigated. The results showed that the composites of PCL and beta-TCP/gelatin microspheres had antibacterial activities for both bacteria. (C) 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Citation Count: 38
Surface Characterization and Radical Decay Studies of Oxygen Plasma-Treated Pmma Films
(Wiley, 2013) Ozgen, Ozge; Özgen, Özge; Aksoy, Eda Ayse; Hasirci, Vasif; Hasirci, Nesrin; Physics Group
Polymethylmethacrylate (PMMA) films were modified by RF oxygen plasma with various powers applied for different periods, and the effects of these parameters on the surface properties such as hydrophilicity, surface free energy (SFE), chemistry, and topography were investigated by water contact angle, goniometer, X-ray photoelectron spectroscopy (XPS), and atomic force microscopy, and the types of the created free radicals and their decay were detected by electron spin resonance spectroscopy (ESR). SFE and contact angle results varied depending on the plasma parameters. Oxygen plasma treatment (100 W-30 min) enhanced the hydrophilicity of PMMA surface as shown by decreasing the water contact angle from 70 degrees to 26 degrees. XPS analysis showed the change in the amounts of the present functionalities as well as formation of new groups as free carbonyl and carbonate groups. The roughness of the surface increased considerably from similar to 2 nm to similar to 75 nm after 100 W-30 min oxygen plasma treatment. ESR analysis indicated the introduction of peroxy radicals by oxygen plasma treatment, and the intensity of the radicals increased with increasing the applied power. Significant decrease in radical concentration was observed especially for the samples treated with higher powers when the samples were kept under the atmospheric conditions. As a conclusion, RF plasma, causes changes in the chemical and physical properties of the materials depending on the applied parameters, and can be used for the creation of specific groups or radicals to link or immobilize active molecules onto the surface of a material. Copyright (C) 2012 John Wiley & Sons, Ltd.