Scopus İndeksli Yayınlar Koleksiyonu / Scopus Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7148
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Article Preparation and Characterization of Hydroxyapatite Reinforced Polymeric Scaffolds(Natl Inst Science Communication-NISCAIR, 2025) Firata, Duygu Doga; Ersoz, Su Turku; Burcu Alp, Fatma; Cetin, Ali Emrah; Ciftcioglu, MuhsinPorous HA reinforced PLA/PCL scaffolds with polymer volume percentages in the 7.0-7.6 range have been prepared by solvent-casting/salt leaching technique. The scaffolds have been characterized by conducting gravimetric measurements, FTIR analysis, TGA, X-ray diffraction analysis, compression tests, cell viability tests, and thermal and hydrolytic degradation tests in order to investigate the effect of PLA/PCL, PLA/HA, PCL/HA and PLA/PCL/HA blending on scaffold properties. Porosity of the scaffolds has been determined to be in the 83-92 percent range. The scaffold porosity has decreased with HA content. The water absorption of the scaffolds has been found to be in between 400 and 750%. The yield strength and the elastic modulus of the scaffolds have been determined to be in the 0.001-0.02 and 5.6-10.6 MPa ranges, respectively. The yield strength of the scaffolds has increased by both PCL and HA contents whereas elastic modulus has increased with PCL content but has decreased with HA content. Mechanical test results have indicated that the addition of HA has increased the strength of the scaffolds while decreasing their flexibility. The activation energies for the thermal degradation of the scaffolds have been determined to be in the 130-398 kJ/mol range and have been shown to be a function of PCL, PLA, and HA content. The hydrolytic degradation behavior of the scaffolds in acetate buffer solutions (pH=4.5) during 127 days and XRD analysis have indicated that the hydrolytic degradation occurring in the amorphous part of the surface film has been diffusion-controlled. The diffusion coefficients of the degradation products in the scaffolds have been estimated to be in the 1.21-4.95x10(-13) m(2)/s range. Cell viability test results have indicated that the composition of the composite scaffold structure has played a determining role in the prepared scaffolds.Article Citation - WoS: 5Citation - Scopus: 5Low Magnitude High Frequency Vibrations Expedite the Osteogenesis of Bone Marrow Stem Cells on Paper Based 3d Scaffolds(Springer, 2020) Karadaş, Özge; Meşe, Gülistan; Özçivici, EnginAnabolic effects of low magnitude high frequency (LMHF) vibrations on bone tissue were consistently shown in the literature in vivo, however in vitro efforts to elucidate underlying mechanisms are generally limited to 2D cell culture studies. Three dimensional cell culture platforms better mimic the natural microenvironment and biological processes usually differ in 3D compared to 2D culture. In this study, we used laboratory grade filter paper as a scaffold material for studying the effects of LHMF vibrations on osteogenesis of bone marrow mesenchymal stem cells in a 3D system. LMHF vibrations were applied 15 min/day at 0.1 g acceleration and 90 Hz frequency for 21 days to residing cells under quiescent and osteogenic conditions. mRNA expression analysis was performed for alkaline phosphatase (ALP) and osteocalcin (OCN) genes, Alizarin red S staining was performed for mineral nodule formation and infrared spectroscopy was performed for determination of extracellular matrix composition. The highest osteocalcin expression, mineral nodule formation and the phosphate bands arising from the inorganic phase was observed for the cells incubated in osteogenic induction medium with vibration. Our results showed that filter paper can be used as a model scaffold system for studying the effects of mechanical loads on cells, and LMHF vibrations induced the osteogenic differentiation of stem cells.Article Citation - WoS: 12Citation - Scopus: 17Fish Scale/Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) Nanofibrous Composite Scaffolds for Bone Regeneration(SAGE Publications, 2020) Kara, Aylin; Güneş, Oylum C.; Albayrak, Aylin Z.; Bilici, Gökçen; Erbil, Güven; Havitcioğlu, HasanThe aim of this study was to produce three-dimensional, nanofibrous fish scale/poly(3-hydroxybutyrate-co-3-hydroxyvalerate) composite scaffolds as bone filling materials. This is the first report wherein fish scales were used within a nanofibrous matrix for bone regeneration. Composite scaffolds with a cotton wool-like structure (fiber diameter: 560 +/- 64 nm; porosity: 82%) were obtained by incorporating chopped fish scales into wet-electrospun poly(3-hydroxybutyrate-co-3-hydroxyvalerate) nanofibers and freeze-drying. The addition of the fish scales improved the mechanical properties, biomineralization tendency, cell viability, alkaline phosphatase activity, and type I collagen production. Consequently, produced composite scaffolds would be regarded to have the therapeutic capacity in bone tissue damages.