Scopus İndeksli Yayınlar Koleksiyonu / Scopus Indexed Publications Collection

Permanent URI for this collectionhttps://hdl.handle.net/11147/7148

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  • Article
    Citation - Scopus: 6
    Sensitive and Rapid Protein Assay Via Magnetic Levitation
    (Elsevier, 2022) Sözmen, Alper Baran; Arslan Yıldız, Ahu
    Magnetic levitation (MagLev) is a newly emerging methodology for biosensing that provides a density-based analysis, which is highly sensitive and versatile. In this study, a magnetic levitation based sensor platform was used for protein detection; and sensor platform optimization was performed for both sensitivity and resolution. Bovine Serum Albumin (BSA) was used as a model protein and detection of BSA was carried out by antibody functionalized polystyrene microspheres (PSMs). Various sizes of PSMs were examined and their performances were compared by statistical analyses in terms of limit of detection (LOD), sensitivity, and resolution. Quantification of the protein was done based on the magnetic levitation height differences of antibody functionalized PSMs. For optimization of the methodology, varied PSMs were utilized, and standardization of PSM diameter, concentration of the antibody to be functionalized, and PSM dilution rates were carried out. In conclusion, 20 μm PSMs diluted to 0.005% W/V and functionalized with anti-BSA antibody at a concentration of 28 μg/ml were determined to provide the best resolution for BSA detection. A dynamic range of 100 nM to 1 mM was observed with an LOD value of 4.1 ng/ml. This sensing platform promises a novel approach with a diverse application field and it provides rapid, consistent, and reproducible results with high resolution and sensitivity.
  • Article
    Citation - WoS: 43
    Citation - Scopus: 46
    Glucuronoxylan-Based Quince Seed Hydrogel: a Promising Scaffold for Tissue Engineering Applications
    (Elsevier, 2021) Güzelgülgen, Meltem; Özkendir İnanç, Dilce; Yıldız, Ümit Hakan; Arslan Yıldız, Ahu
    Natural gums and mucilages from plant-derived polysaccharides are potential candidates for a tissue-engineering scaffold by their ability of gelation and biocompatibility. Herein, we utilized Glucuron-oxylanbased quince seed hydrogel (QSH) as a scaffold for tissue engineering applications. Optimization of QSH gelation was conducted by varying QSH and crosslinker glutaraldehyde (GTA) concentrations. Structural characterization of QSH was done by Fourier Transform Infrared Spectroscopy (MR). Furthermore, morphological and mechanical investigation of QSH was performed by Scanning Electron Microscopy (SEM) and Atomic Force Microscopy (AFM). The protein adsorption test revealed the suitability of QSH for cell attachment. Biocompatibility of QSH was confirmed by culturing NIH-3T3 mouse fibroblast cells on it. Cell viability and proliferation results revealed that optimum parameters for cell viability were 2 mg mi(-1)of QSH and 0.03 M GTA. SEM and DAPI staining results indicated the formation of spheroids with a diameter of approximately 300 pm. Furthermore, formation of extracellular matrix (ECM) microenvironment was confirmed with the Collagen Type-I staining. Here, it was demonstrated that the fabricated QSH is a promising scaffold for 3D cell culture and tissue engineering applications provided by its highly porous structure, remarkable swelling capacity and high biocompatibility. (C) 2021 Published by Elsevier B.V.
  • Correction
    Citation - WoS: 2
    Citation - Scopus: 2
    Correction: Scaffold-Free Three-Dimensional Cell Culturing Using Magnetic Levitation
    (Royal Society of Chemistry, 2018) Türker, Esra; Demircak, Nida; Arslan Yıldız, Ahu
    The 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: 75
    Citation - Scopus: 74
    Scaffold-Free Three-Dimensional Cell Culturing Using Magnetic Levitation
    (Royal Society of Chemistry, 2018) Türker, Esra; Demirçak, Nida; Arslan Yıldız, Ahu
    Three-dimensional (3D) cell culture has emerged as a pioneering methodology and is increasingly utilized for tissue engineering, 3D bioprinting, cancer model studies and drug development studies. The 3D cell culture methodology provides artificial and functional cellular constructs serving as a modular playground prior to animal model studies, which saves substantial efforts, time and experimental costs. The major drawback of current 3D cell culture methods is their dependency on biocompatible scaffolds, which often require tedious syntheses and fabrication steps. Herein, we report an easy-to-use methodology for the formation of scaffold-free 3D cell culture and cellular assembly via magnetic levitation in the presence of paramagnetic agents. To paramagnetize the cell culture environment, three different Gadolinium(iii) chelates were utilized, which led to levitation and assembly of cells at a certain levitation height. The assembly and close interaction of cells at the levitation height where the magnetic force was equilibrated with gravitational force triggered the formation of complex 3D cellular structures. It was shown that Gd(iii) chelates provided an optimal levitation that induced intercellular interactions in scaffold-free format without compromising cell viability. NIH 3T3 mouse fibroblasts and HCC827 non-small-cell lung cancer cells were evaluated via the magnetic levitation system, and the formation of 3D cell culture models was validated for both cell lines. Hereby, the developed magnetic levitation system holds promises for complex cellular assemblies and 3D cell culture studies.
  • Article
    Citation - WoS: 46
    Citation - Scopus: 57
    Recent Advances in Magnetic Levitation: a Biological Approach From Diagnostics To Tissue Engineering
    (American Chemical Society, 2018) Türker, Esra; Arslan Yıldız, Ahu
    The magnetic levitation technique has been utilized to orientate and manipulate objects both in two dimensions (2D) and three dimensions (3D) to form complex structures by combining various types of materials. Magnetic manipulation holds great promise for several applications such as self-assembly of soft substances and biological building blocks, manipulated tissue engineering, as well as cell or biological molecule sorting for diagnostic purposes. Recent studies are proving the potential of magnetic levitation as an emerging tool in biotechnology. This review outlines the advances of newly developing magnetic levitation technology on biological applications in aqueous environment from the biotechnology perspective.
  • Conference Object
    Citation - Scopus: 2
    Utilization of Near Ir Absorbing Gold Nanocolloids by Green Synthesis
    (Trans Tech Publications, 2018) Elveren, Beste; Yıldız, Ümit Hakan; Arslan Yıldız, Ahu
    The rapid developments in nanoscience, and its applications on biomedical areas have a large impact on drug delivery, tissue engineering, sensing, and diagnosis. Gold is widely investigated nanomaterial for the last couple of decades, since it has unique surface properties and very low toxicity to biological environment. In this work, we present a novel synthesis of gold nanoparticles (GNPs) exhibiting both visible and near-IR absorbance without agglomeration. The surface of GNPs were analyzed by routine methods and the binding kinetics were investigated by Surface Plasmon Resonance (SPR) Spectroscopy. The unique optical properties of near-IR asorbing GNP colloids hold promise for biological applications.
  • Article
    Citation - WoS: 79
    Citation - Scopus: 94
    Biofabrication of in Situ Self Assembled 3d Cell Cultures in a Weightlessness Environment Generated Using Magnetic Levitation
    (Nature Publishing Group, 2018) Anıl İnevi, Müge; Yaman, Sena; Arslan Yıldız, Ahu; Meşe, Gülistan; Yalçın Özuysal, Özden; Tekin, Hüseyin Cumhur; Özçivici, Engin
    Magnetic levitation though negative magnetophoresis is a novel technology to simulate weightlessness and has recently found applications in material and biological sciences. Yet little is known about the ability of the magnetic levitation system to facilitate biofabrication of in situ three dimensional (3D) cellular structures. Here, we optimized a magnetic levitation though negative magnetophoresis protocol appropriate for long term levitated cell culture and developed an in situ 3D cellular assembly model with controlled cluster size and cellular pattern under simulated weightlessness. The developed strategy outlines a potential basis for the study of weightlessness on 3D living structures and with the opportunity for real-time imaging that is not possible with current ground-based simulated weightlessness techniques. The low-cost technique presented here may offer a wide range of biomedical applications in several research fields, including mechanobiology, drug discovery and developmental biology.
  • Conference Object
    Kanser Öntanısı için Hücredışı Veziküller Kullanılarak Plazmonik Temelli Metodoloji Geliştirme
    (Institute of Electrical and Electronics Engineers Inc., 2017) Erdoğan, Duygu; Alduran, Yeşim; Yıldız, Ümit Hakan; Arslan Yıldız, Ahu
    Son yıllarda, vücut sıvılarında bulunan hücredışı veziküller kanserde tanı biyobelirteci olarak kullanılmaktadır. Veziküllerin içeriği kanserin türünü ve seviyesini belirlemede rol oynayabilmektedir. Bu vezikülleri yakalama işleminde, genel olarak, Akış Sitometrisi (Flow cytometry), Western Blot, Enzime-bağlı İmmunosorbent Deneyi (ELISA) ve Yüzey Plazmon Rezonansı (SPR) metodolojileri kullanılmaktadır. Bu çalışmada vezikülleri yakalamaya yönelik plazmon temelli bir deney platformu üretilmesi önerilmiştir. Bu plazmonik platform, yüzeyde yapılacak modifikasyonlarla, yüksek hassasiyet oluşturabileceğimiz Lokalize Yüzey Plazmon Resonansı temellidir.
  • Conference Object
    Üç Boyutlu Hücre Kültürü için Polimer Esaslı Ekstrasellüler Matriks Mimetiği
    (Institute of Electrical and Electronics Engineers Inc., 2017) Türker, Esra; Yıldız, Ümit Hakan; Arslan Yıldız, Ahu
    Elektro-eğirme metodu gelişmiş üretim teknolojilerindendir ve biyomedikal uygulamalarında yaygın olarak kullanılmaktadır. Özellikle doku mühendisliğinde amaç, çalışılacak doku üzerine doğal veya sentetik destek materyali (iskele) üreterek hücrenin uyum sağlayabileceği bir ortam oluşturmaktır. Bu projenin amacı üç boyutlu (3D) hücre kültürü çalışmaları için elektro-eğirme-metodu ile poli(L-laktik-co-epsilon-kaprolakton) (PLLCL) kullanılarak iskele üretilmesidir. Homojen lifler ve uygun gözenek boyutu elde etmek amacıyla optimizasyon çalışmaları yapılmıştır. Elde edilen liflerin çapı, akış hızı ve voltajın artmasıyla azalmaktadır. Taramalı uç elektron mikroskop incelemeleri (SEM) lif morfolojik yapılarının doku iskelesi fabrikasyonu için ideale yakın olduğunu ortaya çıkarmıştır.