Scopus İndeksli Yayınlar Koleksiyonu
Permanent URI for this collectionhttps://hdl.handle.net/20.500.12573/395
Browse
11 results
Search Results
Article Engineering a Bilayered Scaffold as a Potential Cardiac Patch: From Scaffold Design to in Vitro Assessment(Springer Singapore Pte Ltd, 2025-11-24) Yuruk, Adile; Duzler, Ayhan; Isoglu, Sevil Dincer; Isoglu, Ismail AlperIn this study, we developed a novel bilayered scaffold consisting of a bottom layer composed of the Decellularized Bovine Pericardium (DP) coated with Polyaniline Nanoparticles (PANINPs) and a top layer made of an electrospun Poly(lactic-co-glycolic acid)/Gelatin (PLGA/Gel) membrane incorporated with Vascular Endothelial Growth Factor (VEGF) and hawthorn extract. Functionally, the DP supplies native Extracellular Matrix (ECM) components and mechanical support, while PANINPs provide conductivity. The electrospun PLGA/Gel layer mimics fibrous ECM. It incorporates bioactives, with VEGF promoting pro-angiogenic stimulation and hawthorn extract enhancing anticoagulant activity, as well as increasing surface hydrophilicity. The tissue adhesive ensures the interfacial integrity between the two layers. Decellularization efficiency was confirmed histologically using 4 ',6-diamidino-2-phenylindole (DAPI) and Hematoxylin-Eosin (H&E) staining. The DP exhibited a DNA content of 115.9 +/- 47.8 ng/mg DNA, compared to 982.88 +/- 395.42 ng/mg in Native Pericardium (NP). The PANINPs had an average particle size of 104.94 +/- 13.7 nm. The conductivity of PANINPs-coated decellularized pericardium was measured to be 9.093 +/- 8.6 x 10- 4 S/cm using the four-point probe method. PLGA/Gel membranes containing hawthorn extract (1%, 5%, 10%, and 15% w/v) and VEGF (0.1 mu g/mL, 0.5 mu g/mL, and 1 mu g/mL) were fabricated by electrospinning, resulting in fiber diameters between 850 and 1200 nm and pore sizes between 14 and 20 mu m. The anticoagulant efficiency of the membranes containing hawthorn extract reached 430 s in the Activated Partial Thromboplastin Time Assay (aPTT). Mechanical testing revealed a tensile strength of 22.70 +/- 6.33 MPa, an elongation of 53.58 +/- 10.63%, and Young's modulus of 0.67 +/- 0.10 MPa. The scaffold also exhibited over 91% cell viability and excellent cardiomyocyte adhesion. The hemolysis ratio was determined to be 0.421 +/- 0.191%, which confirms its blood compatibility. Our results indicate that the proposed bilayered scaffold can be a promising candidate for cardiac patch applications.Master Thesis Centella asiatica extract containing bilayered electrospun wound dressing(Abdullah Gül Üniversitesi, 2019) KOÇ, NURAY; İşoğlu, İsmail AlperInnovative and bioactive wound dressings prepared by electrospinning mimicking the native structure of the extracellular matrix (ECM) have gained significant interest as an alternative to conventional wound care applications. In this study, bilayered wound dressing material was produced by sequential electrospinning of quaternized poly(4- vinyl pyridine) (upper layer) on the Centella Asiatica (CA) extract containing electrospun poly(D, L-lactide-co-glycolide) (PLGA)/poly(3-hydroxybutyrate-co-3- hydroxy valerate) (PHBV) blend membrane (lower layer). Scanning electron microscopy (SEM) was utilized to show a uniform and bead-free fiber structure of electrospun membranes. The average diameter of CA extract containing electrospun PLGA/PHBV blend membrane was calculated 0.471±0.11 µm, whereas the average fiber diameter of electrospun poly(Q-VP) membranes was in the range of 0.460±0.057 µm. Chemical, thermal, mechanical properties, and adsorption capacity of electrospun membranes, as well as the cumulative release of CA from the electrospun PLGA/PHBV membrane, were investigated. Viability, adhesion, and attachment of human fibroblast cells on the electrospun membranes on pre-set days were evaluated by the colorimetric CellTiter 96® Aqueous One Solution Cell Proliferation Assay (MTS assay) and SEM. Results revealed that CA loaded bilayered electrospun wound dressing showed promoted attachment and proliferation of fibroblasts. Hence, it can be concluded that CA extract containing bilayered electrospun wound dressing prepared in this study has a promising potential for wound healing applications.Article Citation - WoS: 8Citation - Scopus: 11Stem Cells Combined 3D Electrospun Nanofibrous and Macrochannelled Matrices: A Preliminary Approach in Repair of Rat Cranial Bones(Taylor & Francis Ltd, 2019-04-03) Isoglu, Ismail Alper; Bolgen, Nimet; Korkusuz, Petek; Vargel, Ibrahim; Celik, Hakan Hamdi; Kilic, Emine; Piskin, ErhanRepair of cranial bone defects is an important problem in the clinical area. The use of scaffolds combined with stem cells has become a focus in the reconstruction of critical-sized bone defects. Electrospinning became a very attracting method in the preparation of tissue engineering scaffolds in the last decade, due to the unique nanofibrous structure of the electrospun matrices. However, they have a limitation for three dimensional (3D) applications, due to their two-dimensional structure and pore size which is smaller than a cellular diameter which cannot allow cell migration within the structure. In this study, electrospun poly(epsilon-caprolactone) (PCL) membranes were spirally wounded to prepare 3D matrices composed of nanofibers and macrochannels. Mesenchymal stromal/stem cells were injected inside the scaffolds after the constructs were implanted in the cranial bone defects in rats. New bone formation, vascularisation and intramembranous ossification of the critical size calvarial defect were accelerated by using mesenchymal stem cells combined 3D spiral-wounded electrospun matrices.Article Citation - WoS: 14Citation - Scopus: 15Preparation of Antibacterial Electrospun Poly(D, L-Lactide-co-Glycolide)/Gelatin Blend Membranes Containing Hypericum Capitatum Var. Capitatum(Taylor & Francis As, 2020-05-18) Aksit, Nazende Nur; Gurdap, Seda; Isoglu, Sevil Dincer; Isoglu, Ismail AlperIn this study, we fabricated poly(D, L-lactide-co-glycolide)/gelatin (PLGA/gelatin) membranes containing different amounts of Hypericum capitatum var. capitatum (HCC) extract (1, 5, 7.5, 10 wt%) by electrospinning technique. We investigated chemical, morphological, physical, and mechanical properties as well as in vitro degradation behavior of the electrospun membranes. We also evaluated the antibacterial activity of the electrospun membranes against Escherichia coli and Staphylococcus aureus. Viability, adhesion, and attachment of human fibroblast cells on the electrospun membranes on pre-set days were evaluated by the colorimetric CellTiter 96(R) AQueous One Solution Cell Proliferation Assay (MTS assay), scanning electron microscopy (SEM), and 4',6-Diamidino-2-Phenylindole (DAPI) staining.Article Citation - WoS: 5Citation - Scopus: 5Preparation and Characterization of Viburnum Opulus Containing Electrospun Membranes as Antibacterial Wound Dressing(Korean Fiber Soc, 2023-09-22) Yuruk, Adile; Isoglu, Sevil Dincer; Isoglu, Ismail AlperHerein, we fabricated polycaprolactone/gelatin electrospun membranes possessing different amounts of Viburnum Opulus extract (0, 25, 35, 50%, w/v) as an antibacterial wound dressing. We investigated chemical, morphological, physical, and mechanical properties as well as in vitro degradation behavior of the electrospun membranes. The antibacterial activities of membranes were evaluated against gram-positive Staphylococcus aureus (S. aureus) and gram-negative Escherichia coli (E. coli). The membranes containing Viburnum Opulus exhibited excellent antibacterial activity with the formation of inhibition zones of 25 mm to 36 mm against Escherichia coli and 14 mm to 25 mm against Staphylococcus aureus. The fiber diameters rose from 591 to 1222 nm after adding Viburnum Opulus extract. The extract-containing membranes displayed superior swelling, cell viability, and proliferation properties to neat membranes. Our results showed that the polycaprolactone/gelatin electrospun membranes containing Viburnum Opulus could be a suitable material for wound dressing applications.Article Citation - WoS: 11Citation - Scopus: 13On the Detailed Mechanical Response Investigation of PHBV/PCL and PHBV/PLGA Electrospun Mats(IOP Publishing Ltd, 2019-03-29) Bal, Burak; Tugluca, Ibrahim Burkay; Koc, Nuray; Isoglu, Ismail AlperIn this study, electrospun mats of pristine poly(epsilon-caprolactone) (PCL), Poly(D, L-lactide-co-glycolide) (PLGA), poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV), as well as PHBV/PCL blends and PHBV/PLGA blends in different ratios (80:20, 75:25, 50:50, 25:75, 20:80, 10:90, 5:95%, w/w) and Centella Asiatica (CA) loaded (1, 5, 10%, w/v) PHBV/PCL and PHBV/PLGA polyester blends were prepared. Electrospun mats were characterized by scanning electron microscopy (SEM) in order to show uniform and bead and defect-free fiber structure with average diameter. The blend ratio and strain rate dependencies of mechanical behavior of these electrospun membranes were investigated under tensile loading. The tensile tests were conducted at an initial strain rates of 10(-1) s(-1), 10(-2) s(-1), 10(-3) s(-1) and 10(-4) s(-1) at room temperature and the best and worst combinations of PHBV/PLGA, PHBV/PCL blend ratios for both stress and ductility required applications were specified for each strain rate. The effects of blend ratios on the tensile strength and Young's modulus were also investigated. Moreover, the effects of Centella Asiatica on the electrospun membranes' mechanical behavior were demonstrated at different strain rates. Consequently, this study constitutes an important guideline for the selection and usage of the aforementioned electrospun membranes as a wound dressing material in terms of mechanical response at different loading scenarios.Article Citation - WoS: 3Citation - Scopus: 3Investigations of Strain Rate, Size, and Crack Length Effects on the Mechanical Response of Polycaprolactone Electrospun Membranes(Sage Publications Ltd, 2021-06-18) Bayram, Ferdi C.; Kapci, Mehmet F.; Yuruk, Adile; Isoglu, Ismail A.; Bal, BurakThe effects of strain rate, size (height x width), and pre-existing crack length on the mechanical response of polycaprolactone electrospun membranes were investigated by tension tests conducted at room temperature. In particular, tensile tests were performed with three different strain rates for strain rate effect tests, seven different geometries for elucidating the size effect, and three different initial notch lengths for crack growth experiments. The electrospun membranes were produced by the electrospinning technique using a polycaprolactone solution prepared in 1, 1, 1, 3, 3, 3-hexafluoro-2-propanol as the solvent. Scanning electron microscopy was utilized to show the continuous fiber structure without bead formation. The average fiber diameter was calculated as 1.113 +/- 0.270 mu m by using scanning electron microscopy images of the membranes. The chemical structure of polycaprolactone was analyzed by Fourier transform infrared spectroscopy, and the toxicity and cell viability of the electrospun membranes were shown by CellTiter 96(R) Aqueous One Solution Cell Proliferation Assay (MTS test). It was observed that the ultimate tensile strength and Young's modulus decreased, and the elongation at failure value increased as the strain rate decreased from 10(-1) to 10(-3) s(-1). Besides, positive strain rate sensitivity was observed on the mechanical response of electrospun polycaprolactone membranes. Moreover, the dependency of mechanical response on the size geometry has been well studied, and the optimum height and width combinations were specified. Also, crack growth was studied in terms of both macroscopic and microstructural deformation mechanisms and it is observed that individual fiber deformations and interactions are highly effective on the mechanical behavior and also propagation of the crack. Consequently, in this study, the size and strain rate effects and crack growth on the mechanical response of electrospun polycaprolactone membranes have been investigated extensively, and the results presented herein constitute an essential guideline for the usage of polycaprolactone electrospun membranes at different loading scenarios.Article Citation - WoS: 14Citation - Scopus: 18Fabrication and Electrochemical Behavior Study of Nano-Fibrous Sodium Titanate Composite(Elsevier Science Bv, 2017-02) Ge, Yeqian; Zhu, Jiadeng; Dirican, Mahmut; Jia, Hao; Yanilmaz, Meltem; Lu, Yao; Zhang, XiangwuNanofiber structured Na2Ti3O7 was synthesized via electrospinning process which was further used as an anode material for sodium-ion batteries for the first time. One-dimensional construction of Na2Ti3O7 composite could contribute to better electrochemical activity. It was demonstrated that the capacity of Na2Ti3O7 nanofibers was significantly improved to 257.8 mAh g(-1) at 30 mA g(-1). Furthermore, the rate capability of Na2Ti3O7 nanofibers was significantly enhanced, showing charge capacities were 161.8, 116.5, and 72.4 mAh g(-1) at 100, 200, and 400 mA g(-1), respectively. Therefore, improved specific capacity and rate capability made Na2Ti3O7 nanofibers composite as a promising anode material for sodium-ion batteries.Article Citation - WoS: 56Citation - Scopus: 63Enhanced Hydrophilicity and Mechanical Robustness of Polysulfone Nanofiber Membranes by Addition of Polyethyleneimine and Al2O3 Nanoparticles(Elsevier, 2017-10) Uzal, Nigmet; Ates, Nuray; Saki, Seda; Bulbul, Y. Emre; Chen, YongshengA novel hydrophilic and mechanically robust polysulfone (PSF) nanofiber membrane (NFM) was prepared by electrospinning of a PSF solution blended with polyethyleneimine (PEI) and Al2O3 nanoparticles. The influence of PEI and Al2O3 nanoparticles concentration on the NFM characteristics was studied using scanning electron microscopy (SEM), Fourier transform infrared FT-IR spectroscopy, porosity, water contact angle measurement, and tensile strength test. Filtration performance of the nanofiber membranes (NFMs) were evaluated by the measurement of pure water flux (PWF) and bovine serum albumin (BSA) rejection tests. According to the results, blending PSF solution with 2 wt.% PEI and 0.05 wt.% Al2O3 nanoparticles resulted in formation of NFMs with high porosity and increased mechanical strength, which exhibited a low water contact angle of 23.5 and high water flux of 28,456 L/m(2) h. On the other hand, incorporation of nanoparticles and PEI in the PSF membrane matrix led to increasing of tensile strength that it was changed from 0.15 to 0.69 for pure PSF and PSF/PEI/Al2O3, respectively. A-24 and 48% BSA rejection performances were obtained by nanoparticle incorporated PSF membranes. In conclusion, the studies strongly suggest that blending with hydrophilic additives of NFMs can enhance the hydrophilicity and mechanical strength of PSF membranes and these NFMs can be effectively used in water based membrane systems. (C) 2017 Elsevier B.V. All rights reserved.Article Citation - WoS: 5Citation - Scopus: 6Centella Asiaticaextract Containing Bilayered Electrospun Wound Dressing(Korean Fiber Soc, 2020-07) Isoglu, Ismail Alper; Koc, NurayInnovative and bioactive wound dressings prepared by electrospinning mimicking the native structure of the extracellular matrix (ECM) have gained significant interest as an alternative to conventional wound care applications. In this study, bilayered wound dressing material was produced by sequential electrospinning of quaternized poly(4-vinyl pyridine) (upper layer) on theCentella Asiatica(CA) extract containing electrospun poly(D, L-lactide-co-glycolide) (PLGA)/poly(3-hydroxybutyrate-co-3-hydroxy valerate) (PHBV) blend membrane (lower layer). Scanning electron microscopy (SEM) was utilized to show a uniform and bead-free fiber structure of electrospun membranes. The average diameter of CA extract containing electrospun PLGA/PHBV blend membrane was calculated 0.471 +/- 0.11 mu m, whereas the average fiber diameter of electrospun poly(Q-VP) membranes was in the range of 0.460 +/- 0.057 mu m. Chemical, thermal, mechanical properties, and adsorption capacity of electrospun membranes, as well as the cumulative release of CA from the electrospun PLGA/PHBV membrane, were investigated. Viability, adhesion, and attachment of human fibroblast cells on the electrospun membranes on pre-set days were evaluated by the colorimetric CellTiter 96 (R) Aqueous One Solution Cell Proliferation Assay (MTS assay) and SEM. Results revealed that CA loaded bilayered electrospun wound dressing showed promoted attachment and proliferation of fibroblasts. Hence, it can be concluded that CA extract containing bilayered electrospun wound dressing prepared in this study has a promising potential for wound healing applications.