Sürdürülebilir Yeşil Kampüs Koleksiyonu / Sustainable Green Campus Collection

Permanent URI for this collectionhttps://hdl.handle.net/11147/7755

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Author: search.filters.author.Arslan Yıldız, Ahu

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Now showing 1 - 6 of 6
  • 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.
  • Master Thesis
    Green Synthesis of Metal Nanoparticles and Their Applications as Plasmonic Substrates
    (Izmir Institute of Technology, 2018) Elveren, Beste; Arslan Yıldız, Ahu; Yıldız, Ümit Hakan
    Gold nanoparticles (GNPs) have been widely used in diagnostic, tissue engineering, and drug delivery fields, in the last decades. Generally, reducing gold salts to zero valent gold has been accomplished by harsh chemicals and strong reducing agents, which cause toxicity and eventually limiting the bioapplications. Green synthesis is a newly developing methodology to synthesize GNPs. Especially natural products and plants extracts are commonly preferred for green synthesis based on their natural content. Biological molecule-capped GNPs, are more biofriendly and biocompatible nano-materials that can be used for varied applications.1-3 Sensor applications; varying from biosensing to environmental analysis, are an important field that GNPs were intensively utilized.4-5 Cyanide ion (CN-) has been considered as one of the main pollutants of water, because of its rapid discharge. CN- is currently being used in industry such as; polymer synthesis6, noble metal mining7, pest control8, plastics production etc., at large scale. However, there is an unmet need for CN- detection and monitoring. Colorimetric detection of CN- that utilizes GNPs has been done by several researchers.9-10 However, in all these studies reduction of GNPs were done by strong reducing agents. Green synthesis of GNPs eliminates the toxic side-products that can be harmful to both environment and human health. To overcome this problem green synthesized GNPs were used to establish the sensor platform, which can be further employed for CN- detection. Oxidation of GNPs in the presence of cyanide molecules is a direct-forward, colorimetric and optical method that requires no toxic chemicals; therefore it is a greener approach towards CN- detection in water resources.
  • 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
    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.