WoS İndeksli Yayınlar Koleksiyonu
Permanent URI for this collectionhttps://hdl.handle.net/20.500.12573/394
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Article Citation - WoS: 13Citation - Scopus: 13Sulfobetaine-Based Homo- and Copolymers by Raft: Cross-Linked Micelles and Aqueous Solution Properties(Amer Chemical Soc, 2022-08-04) Gurdap, Seda; Bayram, Nazende Nur; Isoglu, Ismail Alper; Isoglu, Sevil Dincer; Dinçer İşoǧlu, SevilIn this study, we describe the synthesis and aqueous solution behavior of temperature-sensitive N-(3-sulfopropyl)-N-methacroyloxyethyl-N,N-dimethylammonium betaine (SBMA) homopolymers and core cross-linked micelles (CCMs) with an SBMA shell. Reversible addition- fragmentation chain transfer polymerization has been utilized to synthesize sulfobetaine homopolymers, followed by CCM formation during copoly-merization in the presence of an acid-degradable cross-linker. First, SBMA homopolymers of varying chain lengths were synthesized, and it has been demonstrated that an increase in the chain length and concentration of the homopolymer resulted in an increase in the upper critical solution temperature (UCST). Besides, micelles showed concentration-dependent dual temperature-sensitive behavior with UCST and LCST transitions. Also, homopolymers and CCMs were characterized by FTIR, H-1-NMR, GPC, and TEM. Micelle formation and temperature sensitivity were also investigated by DLS. As a result, stabilized micelles were successfully prepared with the motivation of preventing premature drug release and achieving a pH-and temperature-controlled system. Due to their dual-responsive characteristics, the CCMs show promising potential to be used as smart drug carriers for controlled delivery.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: 8Citation - Scopus: 7Raft-Synthesized Poegma-B Block Copolymers: Preparation of Nanosized Micelles for Anticancer Drug Release(Springer, 2021-11-14) Bayram, Nazende Nur; Topuzogullari, Murat; Isoglu, Ismail Alper; Isoglu, Sevil Dincer; Dinçer İşoğlu, SevilTo achieve high stability and biocompatibility in physiological environment, oligoethyleneglycol methacrylate (OEGMA) and 4-vinylpyridine (4VP)-based amphiphilic block copolymers were prepared as micellar carriers to deliver doxorubicin into tumor cells. First, macroinitiator of OEGMA was synthesized by RAFT polymerization at [M](0)/[CTA](0)/[I](0) ratio of 100/1/0.2 in dimethylformamide (DMF) at 70 degrees C, in the presence of 4,4'-azobis(4-cyanovaleric acid) (ACVA) as initiator and 4-cyano-4-(thiobenzoylthio)pentanoic acid (CTA) as chain transfer agent, respectively. It was followed by copolymerization with 4-VP at similar conditions. The formation of RAFT-mediated polymers was approved by FTIR, H-1-NMR and GPC. For the preparation of drug-loaded micelles, a dialysis method was applied and hydrophobic doxorubicin, as a model drug, was entrapped into the micelles. Size distributions and morphologies of drug-loaded micelles were investigated by light scattering and scanning electron microscopy, respectively. Critical micelle concentration was estimated as 0.0019 mg/mL by measuring light scattering intensity in different polymer concentrations. Also, drug loading and entrapment efficiencies were calculated as 4.41% and 17.65% by measuring the DOX amount in the micelles, spectrophotometrically. At last, the drug-loaded micelles were applied to SKBR-3 breast cancer cell lines and revealed up to %40 cell inhibition at 48 and 72 h. As a result, these nanosized and biocompatible micelles can be used for the delivery of hydrophobic drugs, and they can also be modified for further targeting and imaging applications toward specific cancer cells. [GRAPHICS] .Article Citation - WoS: 8Citation - Scopus: 8RAFT-Mediated Synthesis of Poly( N-(2-Hydroxypropyl)Methacrylamide-b-4-vinylpyridine)by Conventional and Microwave Heating(Springer, 2013-06-14) Ozdemir, Zeynep; Topuzogullari, Murat; Isoglu, Ismail Alper; Dincer, SevilWe report the synthesis of N-(2-hydroxypropyl)methacrylamide (HPMA) macroCTA and HPMA-b-4-Vinylpyridine block copolymers via reversible addition-fragmentation chain transfer (RAFT) reaction. Polymerization was carried out in dimethylformamide (DMF) at 70 A degrees C using 4-Cyano-4(thiobenzoylthio) pentanoic acid as chain transfer agent and AIBN as an initiator. Control over molecular weight and composition was achieved by altering the CTA, monomer and initiator feed ratio. The controlled living character of the polymerization was verified with pseudo-first-order kinetic plots, a linear increase of the molecular weight with conversion, and low polydispersities (PDIs a parts per thousand currency sign 1.2). Effect of microwave heating on the homo- and copolymer formation was investigated and the rates were significantly higher than those observed under conventional heating conditions. These polymerization reactions were in controlled fashion resulting in polymers with low PDIs, too. These polymers have a great potential to be used in developing delivery vehicles and conjugates for further drug or gene delivery applications.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: 3Citation - Scopus: 3Pericardial Fluid and Vascular Tissue Engineering: A Preliminary Study(Ios Press, 2021-03-23) Sonmezer, Dilek; Latifoglu, Fatma; Toprak, Guler; Duzler, Ayhan; Isoglu, Ismail AlperBACKGROUND: The heart is surrounded by a membrane called pericardium or pericardial cavity. OBJECTIVE: In this study, we investigated the pericardial fluid (PF) for coating polycaprolactone (PCL) scaffolds. PFS, which is a PF component, was used for the coating material. In addition to using PFS for surface coating, MED and fetal bovine serum (FBS) were also used for comparison. METHODS: Pericardial fluid cells (PFSc) isolated from PF were cultured on coated PCL scaffolds for 1, 3, and 5 days. Cell viability was determined using 3-(4, 5-di-methylthiazol- 2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay. RESULTS: The MTT assay results showed that the viability of cells on PCL scaffold coated with PFS increased over time (P < 0.005), and cell viability was significantly different between PCL scaffolds coated with PFS and non-coated PCL scaffolds. However, cell viability was significantly higher in the PCL scaffolds coated with PFS than non-coated and coated with FBS, MED, and PCL scaffolds. Scanning electron microscopy (SEM) microscopy images and MTT assay indicated that PFSc are attached, proliferated, and spread on PCL scaffolds, especially on PCL scaffolds coated with PFS. CONCLUSIONS: These results suggest that PFS is a biocompatible material for surface modification of PCL scaffolds, which can be used as a suitable material for tissue engineering applications.Conference Object Peptide Targeted Core Cross-Linked Micelles for Dox Delivery to HER2 Expressing Cancer Cells(Mary Ann Liebert, inc, 2022) Bayram, Nazende Nur; Ulu, Gizem Tugce; Gurdap, Seda; Isoglu, Ismail Alper; Baran, Yusuf; Isoglu, Sevil DincerArticle 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: 3HER2-Specific Peptide (LTWWYSPY) and Antibody (Herceptin) Targeted Core Cross-Linked Micelles for Breast Cancer: A Comparative Study(MDPI, 2023-02-22) Bayram, Nazende Nur; Ulu, Gizem Tugce; Abdulhadi, Nusaibah Abdulsalam; Guerdap, Seda; Isoglu, Ismail Alper; Baran, Yusuf; Isoglu, Sevil Dincer; Gürdap, SedaThis study aims to prepare a novel breast cancer-targeted micelle-based nanocarrier, which is stable in circulation, allowing intracellular drug release, and to investigate its cytotoxicity, apoptosis, and cytostatic effects, in vitro. The shell part of the micelle is composed of zwitterionic sulfobetaine ((N-3-sulfopropyl-N,N-dimethylamonium)ethyl methacrylate), while the core part is formed by another block, consisting of AEMA (2-aminoethyl methacrylamide), DEGMA (di(ethylene glycol) methyl ether methacrylate), and a vinyl-functionalized, acid-sensitive cross-linker. Following this, a targeting agent (peptide (LTVSPWY) and antibody (Herceptin((R)))), in varying amounts, were coupled to the micelles, and they were characterized by H-1 NMR, FTIR (Fourier-transform infrared spectroscopy), Zetasizer, BCA protein assay, and fluorescence spectrophotometer. The cytotoxic, cytostatic, apoptotic, and genotoxic effects of doxorubicin-loaded micelles were investigated on SKBR-3 (human epidermal growth factor receptor 2 (HER2)-positive) and MCF10-A (HER2-negative). According to the results, peptide-carrying micelles showed a higher targeting efficiency and better cytostatic, apoptotic, and genotoxic activities than antibody-carrying and non-targeted micelles. Also, micelles masked the toxicity of naked DOX on healthy cells. In conclusion, this nanocarrier system has great potential to be used in different drug-targeting strategies, by changing targeting agents and drugs.