Scopus İndeksli Yayınlar Koleksiyonu / Scopus Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7148
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Conference Paper Magnetic Levitation-Based Endothelial Cell Sorting(Institute of Electrical and Electronics Engineers Inc., 2023) Ozcan, H.A.; Kecili, S.; Tekin, H.C.Cell sorting for rare cells is crucial for diagnostic purposes. Circulating Endothelial Cells (CECs) can be used as cardiovascular disease markers. Due to the rareness of the CECs in the blood, an accurate, easy, cost and time-effective sorting method is a need. Magnetic levitation is a promising technique for observing differences in the average height of endothelial and white blood cells which does not require any labeling. This study aims to show that the magnetic levitation principle can be used for sorting endothelial cells from the blood. By using paramagnetic medium concentrations of 10 mM and 50 mM, the average levitation height between HUVECs used as a model endothelial cells and U937 cells used as model of white blood cells was measured as 65 μm and 32 μm, respectively. Since there is a significant difference in levitation height for HUVECs and U937 cells, magnetic levitation technology exhibits promising potential for the precise sorting of endothelial cells. © 2023 IEEE.Conference Object Magnetic Levitation-Based Viscosity Measurement in a Microcappilary Channel(Chemical and Biological Microsystems Society, 2022) Doyran, O.; Tekin, H.C.Viscosity, has been known as the key rheological parameter, to characterize biological, chemical and physical material properties. In this work, we have developed a magnetic levitation-based viscosity measurement method in a microcapillary channel. For this purpose, polymer microspheres are utilized as microsensors to correlate solution viscosity to microspheres' velocity while microspheres are balanced at a stable levitation position. This inexpensive and practical system enables rapid viscosity measurement from low amount of sample. © 2022 MicroTAS 2022 - 26th International Conference on Miniaturized Systems for Chemistry and Life Sciences. All rights reserved.Conference Object Assessment of Cell Cycle and Viability of Magnetic Levitation Assembled Cellular Structures(IEEE, 2020) Anıl İnevi, Müge; Ünal, Yağmur Ceren; Yaman, Sena; Tekin, H. Cumhur; Meşe, Gülistan; Meşe, GülistanLabel-free magnetic levitation is one of the most recent Earth-based in vitro techniques that simulate the microgravity. This technique offers a great opportunity to biofabricate scaffold-free 3-dimensional (3D) structures and to study the effects of microgravity on these structures. In this study, self-assembled 3D living structures were fabricated in a paramagnetic medium by magnetic levitation technique and effects of the technique on cellular health was assessed. This magnetic force-assisted assembly system applied here offers broad applications in several fields, such as space biotechnology and bottom-up tissue engineering.Conference Object Citation - Scopus: 2Magnetic Levitation-Based Protein Detection Using Lensless Digital Inline Holographic Microscopy(The Chemical and Biological Microsystems Society (CBMS), 2019) Yaman, Sena; Delikoyun, Kerem; Tekin, Hüseyin CumhurWe present a portable protein detection platform based on magnetic levitation principle integrated with a lensless imaging system. In the platform, polymer microspheres are used to capture selectively target proteins and magnetic nanoparticle labels. The imaging system monitors the levitation height change of polymer microspheres with respect to the presence of target protein on their surfaces. This system enables the detection of target proteins down to ng/mL levels in a short time. © 2019 CBMS-0001.Conference Object Citation - WoS: 7Citation - Scopus: 7Cell Separation With Hybrid Magnetic Levitation-Based Lensless Holographic Microscopy Platform(Institute of Electrical and Electronics Engineers Inc., 2019) Delikoyun, Kerem; Yaman, Sena; Anıl İnevi, Müge; Özçivici, Engin; Tekin, Hüseyin CumhurSeparation of target cells in a heterogeneous solution is of great importance for clinical studies especially for immunology and oncology. Separated cells can be used for diagnostic applications ranging from whole blood counting to isolation of circulating tumor cells (CTC) for personalized medicine. Recent separation technologies rely on labelling and identifying target cells with variety of labelling principle such as fluorescence or magnetic tags. However, they require labor-intensive processes, long analysis time, and expensive chemical reagents and instrumentation. Hence, their usage is limited to well-equipped centralized laboratories. There is a need for a rapid, sensitive, low-cost and automated cell separation technology to disseminate usage of this technology even in rural areas. Magnetic levitation is a powerful cell separation method, which distinguishes cells based on their levitation heights depending on cell density. However, magnetic levitation-based separation technologies require traditional, bulky and expensive microscopes for analysis. Lensless digital inline holographic microscopy (LDIHM) systems are composed of a simple illumination system containing an LED, a pinhole, and an imaging sensor for high-resolution microscopic imaging, which eliminates needs of highly fragile and expensive optics as in traditional microscopy. Here, we introduced a novel hybrid and portable cell separation platform, where magnetic levitation technology is integrated with LDIHM system for automated analysis of cell levitation heights. Using this platform, three different cell lines are successfully separated. Live and dead cells having distinguished levitation heights can be also identified in the platform.Conference Object Citation - Scopus: 2Density-Based Separation of Microparticles Using Magnetic Levitation Technology Integrated on Lensless Holographic Microscopy Platform(Institute of Electrical and Electronics Engineers Inc., 2019) Delikoyun, Kerem; Yaman, Sena; Tekin, Hüseyin CumhurMicroparticle/cell separation is one of the most important applications in the field of biomedical sciences particularly for cell sorting and protein assays. There are variety of different separation technologies introduced in the literature that the main limitations are large amount of sample, expensive chemical use besides of requirement of a labeling procedure (i.e. fluorescent/magnetic labeling), complex machinery, and high operational costs. Magnetic levitation-based separation offers simple, rapid and precise separation of microparticles based on their densities by suspending them in a glass microcapillary between two opposing magnets. Traditionally, magnetic levitation-based microparticle separation and identification procedure is performed by imaging under bulky microscopes composed of fragile and expensive optics and require trained personnel to operate which makes the whole procedure costly, time consuming and prone to human error. Lensless digital inline holographic microscope (LDIHM) eliminates the need for sophisticated optics by replacing simple illumination and recording scheme that can be reduced into few widely-Available and cost-effective components. Thus, inspection procedure is mostly carried out on digitally processing captured holograms so that dependency on optical components and human error is dramatically reduced alongside using cost-effective and handheld device. Here, we introduce a novel hybrid platform that brings the advantages of magnetic levitation system with lensless digital inline holographic microscope for precise separation and identification of microparticles based on their densities. In the platform, it was shown that 1.026 g/mL and 1.090 g/mL microparticles were successfully identified. © 2019 IEEE.Conference Object Citation - WoS: 1Citation - Scopus: 3Microfluidic Platform for Sorting Materials Based on Their Densities Using Magnetic Levitation(Institute of Electrical and Electronics Engineers Inc., 2019) Yılmaz, Esra; Özçivici, Engin; Tekin, Hüseyin CumhurCirculating Tumor Cells (CTCs) play a vital role in cancer diagnosis, prognosis and personalized medicine. However, CTCs are extremely rare in blood (i.e., down to 1-100 CTC per 1 mL human blood) and hard to isolate because of the heterogeneity of CTCs in biomarker expression. The current CTC separation and identification techniques use numerous differences between cells such as size, electric charges, density and expression of cell surface markers. However, these techniques have many limitations in terms of laborious sample preparation steps, inconsistent results caused by low specificity and efficiency and high cost. Hence, there is no standard method for isolating CTCs yet. With this study, it was aimed to fill the gap in CTC isolation and identification by proposing to develop a new method based on magnetic levitation principle, which has recently been demonstrated as a highly acceptable method for biological characterization of cells and monitoring of their cellular events. In this study, we have developed a new label-free microfluidic sorter to separate microparticles/cells based on their densities using magnetic levitation principle. Two different density microparticles (1.02 g/mL and 1.09 g/ mL) have been sorted and quantified in a continuous flow using a set of permanent magnets located in a 3D printed structure surrounding the microfluidic channel. This device can be used for rapid, low cost and label-free in-vitro diagnosis of cancer by sorting CTCs from whole blood in a high-Throughput manner. The sorted cells might further be used for downstream analysis for personalized and precision medicine. © 2019 IEEE.Conference Object Citation - WoS: 3Citation - Scopus: 4Biofabrication of Cellular Structures Using Weightlessness as a Biotechnological Tool(IEEE, 2019) Anıl İnevi, Müge; Sarıgil, Öykü; Yaman, Sena; Yalçın Özuysal, Özden; Meşe, Gülistan; Tekin, Hüseyin Cumhur; Özçivici, EnginGravity is an important biomechanical signal effecting the morphology and function of organisms. Reduction of gravitational forces, as experienced during spaceflight, cause alterations in the biological systems. Magnetic levitation technique is one of the most recent ground-based technology to mimic weightlessness environment. In addition to providing a platform to investigate biological effects of the weightlessness, this platform presents a novel opportunity to biofabricate 3-dimensional (3D) structures in a scaffold-and nozzle-free fashion. In this study, various controllable self-assembled 3D living structures were fabricated via magnetic levitation technique. This strategy may offer an easy and cost-effective opportunity for a wide range of space biotechnology researches.Conference Object Citation - WoS: 4Citation - Scopus: 5Application of Magnetic Levitation Induced Weightlessness To Detect Cell Lineage(IEEE, 2019) Sarıgil, Öykü; Anıl İnevi, Müge; Yılmaz, Esra; Çağan, Melike; Meşe, Gülistan; Tekin, Hüseyin Cumhur; Özçivici, EnginIdentification and classification of bone marrow cells is an important step for molecular biology and therapeutic studies related to bone marrow disorders such as osteoporosis or obesity. In this study, we applied magnetic levitation technology to induce a weightlessness environment to detect adipocytes and osteoblasts based on their single cell density. This biotechnological method can be used for separation of heterogeneous populations such as bone marrow once adapted to a continuous microfluidic platform.