WoS İndeksli Yayınlar Koleksiyonu / WoS Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7150
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Article Citation - WoS: 34Doxorubicin Conjugated, Crosslinked, Pegylated Particles Prepared Via One-Pot Thiol-Ene Modification of a Homopolymer Scaffold: Synthesis and in Vitro Evaluation(Royal Society of Chemistry, 2011) Wong, Lingjiun; Bulmuş Zareie, Volga; Kavallaris, Maria; Bulmuş, Volga; 03.01. Department of Bioengineering; 03. Faculty of Engineering; 01. Izmir Institute of TechnologyDoxorubicin (Dox)-conjugated, poly(ethylene glycol) (PEG) shielded, reversibly crosslinked particles were prepared by a one-pot thiol-ene reaction from a RAFT-synthesized well-defined homopolymer scaffold, poly(pyridyldisulfide ethylmethacrylate) (PPDSM). Dox and PEG modified with maleimide end-groups (mal-Dox and mal-PEG), were covalently attached in one pot to free thiol groups of PPDSM (M-n = 8900 g mol(-1) and PDI = 1.18) in the presence of a disulfide reducing agent. similar to 50% of the total pyridyldisulfide units were conjugated with Dox and PEG (with an equal mol ratio). Particles with an average hydrodynamic diameter of 192 +/- 28 nm were observed to form after conjugation. Incubation of these particles with a disulfide reducing agent resulted in the disassociation of the particles. The release of Dox from the particles was pH dependent. The Dox-conjugated PEGylated particles (with a Dox content of 8 wt%) inhibited the viability of human cervical carcinoma cells (HeLa) with an IC50 value of 8 X 10(-7) M, determined by an Alamar Blue assay, while the IC50 of free Dox was 1 X 10(-7) M. The fluorescence microscopy analyses of the HeLa cells after incubation with the particles for varying times showed that the Dox carried by the particles is taken up efficiently by the cells.Article Citation - WoS: 24Citation - Scopus: 24Defect Tolerant and Dimension Dependent Ferromagnetism in Mnse2(Royal Society of Chemistry, 2019) Eren, İsmail; Eren, İsmail; İyikanat, Fadıl; Şahin, Hasan; Şahin, Hasan; 04.05. Department of Pyhsics; 04.04. Department of Photonics; 04. Faculty of Science; 01. Izmir Institute of TechnologyBy performing density functional theory-based calculations, we investigate the structural, vibrational, electronic and magnetic properties of 2D monolayers, nanoribbons and quantum dots of MnSe2. Vibrational spectrum analysis reveals the dynamical stability of not only ferromagnetic but also antiferromagnetic phases of single layer MnSe2 crystal structures. Electronically, calculations show that 1T-MnSe2 is a ferromagnetic structure displaying metallic behavior. It is also found that the structure preserves its dynamical stability and metallic behavior even under the presence of high density Se vacancies. Moreover, it was predicted that, differing from the 2D MnSe2, metal-metal interaction driven reconstructions result in ferromagnetic-to-antiferromagnetic crossover in the ground state of nanoribbons and quantum dots. With its robust ferromagnetic metallic character in the 2D ultra-thin limit and dimension-dependent magnetic properties, MnSe2 is an important candidate for spintronic device applications.Correction Citation - WoS: 2Citation - Scopus: 2Correction: Scaffold-Free Three-Dimensional Cell Culturing Using Magnetic Levitation(Royal Society of Chemistry, 2018) Türker, Esra; Arslan Yıldız, Ahu; Arslan Yıldız, Ahu; 03.01. Department of Bioengineering; 01.01. Units Affiliated to the Rectorate; 01. Izmir Institute of Technology; 03. Faculty of EngineeringThe authors regret the inclusion of an incorrect figure caption for Fig. 2. The corrected figure caption for Fig. 2 is shown below. Fig. 2 Evaluation of levitation height (z) and density profiles through magnetic levitation. (A) Gd(III) chelates were named as Gx (Gadovist/Gadobutrol), Dx (Dotarem/Gadoteric acid) and Ox (Omniscan/Gadodiamide). (B) Standard curve for PE bead density against levitation height; linear curve fitting gives the standard function for the corresponding curve. (C–E) Levitation height profiles of single NIH 3T3 cells under 30/50/100/200 mM Gd concentrations. Single cell density profiles calculated through standard function of linear fitting.Article Citation - WoS: 21Citation - Scopus: 22Redox-Responsive Release of Active Payloads From Depolymerized Nanoparticles(Royal Society of Chemistry, 2017) Lv, Li-Ping; Jiang, Shuai; İnan, Alper; Landfester, Katharina; Crespy, Daniel; 01. Izmir Institute of TechnologyThe difference in the reactivity of two monomers, aniline (ANI) and 2,5-dimercapto-1,3,4-thiadiazole (DMcT), was employed to design nanoparticles with completely different nanostructures. The monomers were simultaneously polymerized by tandem oxidative polymerization occurring in the miniemulsion droplets. DMcT is also a corrosion inhibitor and its polymer can be depolymerized by reduction, which avoids the unwanted release of the payload DMcT when the capsules are not activated. The redox-responsive release profile of DMcT from the composite particles is controlled by the morphology of the particles and it was investigated for monolithic, multi-hollow, and yolk-shell structures. These PANI/PDMcT composite particles may find potential application in Li-S batteries or in the self-healing systems for corrosion protection.Article Citation - WoS: 3Citation - Scopus: 3Hydrogenated Derivatives of Hexacoordinated Metallic Cu2si Monolayer(Royal Society of Chemistry, 2018) Ünsal, Elif; Şahin, Hasan; Şahin, Hasan; Senger, Ramazan Tuğrul; Senger, Ramazan Tuğrul; 04.04. Department of Photonics; 04.05. Department of Pyhsics; 04. Faculty of Science; 01. Izmir Institute of TechnologyHerein, we carried out first-principles calculations based on density functional theory to investigate the effects of surface functionalization with hydrogen atoms on structural, dynamical and electronic properties of Cu2Si monolayer. Pristine Cu2Si, a metallic monolayer, has a planar hexacoordinate structure. Calculations revealed that the most favorable position of a single H atom on the Cu2Si monolayer is at the top of a Si site. Derivatives of Cu2Si monolayer with various H concentrations were investigated, and by performing phonon calculations, it was found that there are three stable hydrogenated structures. Specific heat of these monolayers was found to increase with the hydrogen concentration at temperatures higher than 100 K. Electronically, the hydrogenated derivatives of Cu2Si monolayer preserve the metallic character.Article Citation - WoS: 15Citation - Scopus: 16Monitoring the Crystal Orientation of Black-Arsenic Via Vibrational Spectra(Royal Society of Chemistry, 2019) Kandemir, Ali; İyikanat, Fadıl; Şahin, Hasan; 04.04. Department of Photonics; 04. Faculty of Science; 01. Izmir Institute of TechnologyIn this study, the structural, mechanical, and vibrational properties of a recently discovered anisotropic ultra-thin material, black-arsenic (b-As), are investigated by using density functional theory. Direction dependent elastic constants such as in-plane stiffness, Young's modulus and Poisson's ratio of single-layer b-As are calculated and compared with those of the structural cousin black-phosphorus (b-P). The calculated Poisson's ratio of b-As for the zigzag direction is nearly 1, which is quite higher than that of b-P, 0.65. Besides, it is found that all the three elastic constants are highly anisotropic and their values in the zigzag direction are almost three times higher than that of the armchair direction. The mechanical strength of the material is also calculated and high-toughness is seen in both armchair and zigzag directions. It is revealed that the material is quite stiff against straining along the zigzag direction; in contrast, it is quite flexible along the armchair direction. Vibrational stability analysis shows that the material is stable up to 9% biaxially applied strain, and 12% and 45% uniaxially applied strain in the zigzag and armchair directions, respectively. Furthermore, the prominent Raman active peaks of the b-As structure show strong anisotropy in the strain dependent vibrational spectra and they can also be used for easy-determination of the crystal orientation of b-As from Raman measurements.Article Citation - WoS: 22Citation - Scopus: 22Characterization of Cd133(+)/Cd44(+) Human Prostate Cancer Stem Cells With Atr-Ftir Spectroscopy(Royal Society of Chemistry, 2019) Güler, Günnur; Güler, Günnur; Güven, Ümmü; Öktem, Gülperi; 04.05. Department of Pyhsics; 04. Faculty of Science; 01. Izmir Institute of TechnologyCurrent cancer treatments destroy the tumor mass but cannot prevent the recurrence of cancer. The heterogeneous structure of the tumor mass includes cancer stem cells that are responsible for tumor relapse, treatment resistance, invasion and metastasis. The biology of these cells is still not fully understood; therefore, effective treatments cannot be developed sufficiently. Herein, attenuated total reflection- Fourier transform infrared (ATR-FTIR) spectroscopy, combined with unsupervised multivariate analysis, was applied to prostate cancer stem cells (CSCs), non-stem cancer cells (non-CSCs) and normal prostate epithelial cells to elucidate the molecular mechanisms and features of CSCs, which are crucial to improving the target specific therapies. This work revealed the spectral differences in the cellular mechanisms and biochemical structures among three different cell types. Particularly, prostate CSCs exhibit differences in the lipid composition and dynamics when compared to other cell types. CSCs also harbor pronounced differences in their major cellular macromolecules, including differences in the protein amount and content (mainly a-helices), the abundance of nucleic acids (DNA/RNA), altered nucleic acid conformation and carbohydrate composition. Interestingly, macromolecules containing the CvO groups and negatively charged molecules having the COO-groups are abundant in prostate CSCs in comparison to prostate non-CSCs and normal prostate cells. Overall, this study demonstrates the potential use of ATR-FTIR spectroscopy as a powerful tool to obtain new insights into the understanding of the CSC features, which may provide new strategies for cancer treatment by selectively targeting the CSCs.Article Citation - WoS: 26Citation - Scopus: 27Electric Charge of Nanopatterned Silica Surfaces(Royal Society of Chemistry, 2019) Özçelik, H. Gökberk; Barışık, Murat; Barışık, Murat; 03.10. Department of Mechanical Engineering; 03. Faculty of Engineering; 01. Izmir Institute of TechnologyThe most recent technologies employ nanoscale surface patterning or roughening in order to engineer desired properties on a surface. Electrokinetic properties at the interface of such surfaces and ionic liquids show different behavior to the well-known theoretical descriptions. Basically, the ionic distribution on the surface differs due to electrical double layer overlap effects in the pits and curvature effects at the tips of surface structures. Generally, the charge density of a surface is assumed to be a material property and surface roughness effects are overlooked in most of the literature. In contrast, we properly calculated the local surface charges based on surface chemistry at the corresponding local ionic concentration (charge regulation) for various surface roughness and solution conditions. The results showed that the surface charge density of silica decreased at the pits but increased at the tips of surface patterns. Even for the simplest case of self-repeating surface structures, the average of local surface charges becomes lower than the theoretical predictions. Based on numerical calculations, a phenomenological model was developed as an extension to the existing flat surface theory, which can successfully predict the average surface charge on a nano patterned surface as a function of the surface pattern size, ionic concentration and pH.Article Citation - WoS: 22Citation - Scopus: 22Fluorescein Propiolate: a Propiolate- Decorated Fluorescent Probe With Remarkable Selectivity Towards Cysteine(Royal Society of Chemistry, 2019) Karakuş, Erman; Sayar, Melike; Kaya, Beraat Umur; Kaya, Beraat Umur; Emrullahoğlu, Mustafa; Dartar, Suay; Emrullahoğlu, Mustafa; 04.01. Department of Chemistry; 01. Izmir Institute of Technology; 04.04. Department of Photonics; 04. Faculty of ScienceA fluorescent probe decorated with an alkynyl ester unit (e.g. propiolate) displayed a selective turn-on type fluorescent response towards cysteine. Following a sequential addition-cyclisation pathway mediated by the addition of cysteine, the pre-fluorescent dye rapidly transformed into a new structure and induced a fluorescent response clearly observable with the naked eye.Article Citation - WoS: 34Citation - Scopus: 43Label-Free Density-Based Detection of Adipocytes of Bone Marrow Origin Using Magnetic Levitation(Royal Society of Chemistry, 2019) Özçivici, Engin; Anıl İnevi, Müge; Sarıgil, Öykü; Meşe Özçivici, Gülistan; Tekin, Hüseyin Cumhur; Özçivici, Engin; 03.01. Department of Bioengineering; 01. Izmir Institute of Technology; 04.03. Department of Molecular Biology and Genetics; 03. Faculty of Engineering; 04. Faculty of ScienceAdipocyte hypertrophy and hyperplasia are important parameters in describing abnormalities in adipogenesis that are concomitant to diseases such as obesity, diabetes, anorexia nervosa and osteoporosis. Therefore, technical developments in the detection of adipocytes become an important driving factor in adipogenesis research. Current techniques such as optical microscopy and flow cytometry are available in detection and examination of adipocytes, driving cell- and molecular-based research of adipogenesis. Even though microscopy techniques are common and straightforward, they are restricted in terms of manipulation and separation of the cells. Flow cytometry is an alternative, but mature adipocytes are fragile and cannot withstand the flow process. Other separation methods usually require labeling of the cells or usage of microfluidic platforms that utilize fluids with different densities. Magnetic levitation is a novel label-free technology with the principle of movement of cells towards the lower magnetic field in a paramagnetic medium depending on their individual densities. In this study, we used a magnetic levitation device for density-based single cell detection of differentiated adipogenic cells in heterogeneous populations. Results showed that the magnetic levitation platform was sensitive to changes in the lipid content of mesenchymal stem cells committed to adipogenesis and it could be successfully used to detect the adipogenic differentiation of the cells.