Molecular Biology and Genetics / Moleküler Biyoloji ve Genetik
Permanent URI for this collectionhttps://hdl.handle.net/11147/9
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Article Citation - WoS: 24Citation - Scopus: 30Hologlev: a Hybrid Magnetic Levitation Platform Integrated With Lensless Holographic Microscopy for Density-Based Cell Analysis(American Chemical Society, 2021) Delikoyun, Kerem; Yaman, Sena; Yılmaz, Esra; Sarıgil, Öykü; Anıl İnevi, Müge; Telli, Kübra; Yalçın Özuysal, ÖzdenIn clinical practice, a variety of diagnostic applications require the identification of target cells. Density has been used as a physical marker to distinguish cell populations since metabolic activities could alter the cell densities. Magnetic levitation offers great promise for separating cells at the single cell level within heterogeneous populations with respect to cell densities. Traditional magnetic levitation platforms need bulky and precise optical microscopes to visualize levitated cells. Moreover, the evaluation process of cell densities is cumbersome, which also requires trained personnel for operation. In this work, we introduce a device (HologLev) as a fusion of the magnetic levitation principle and lensless digital inline holographic microscopy (LDIHM). LDIHM provides ease of use by getting rid of bulky and expensive optics. By placing an imaging sensor just beneath the microcapillary channel without any lenses, recorded holograms are processed for determining cell densities through a fully automated digital image processing scheme. The device costs less than $100 and has a compact design that can fit into a pocket. We perform viability tests on the device by levitating three different cell lines (MDA-MB-231, U937, D1 ORL UVA) and comparing them against their dead correspondents. We also tested the differentiation of mouse osteoblastic (7F2) cells by monitoring characteristic variations in their density. Last, the response of MDA-MB-231 cancer cells to a chemotherapy drug was demonstrated in our platform. HologLev provides cost-effective, label-free, fully automated cell analysis in a compact design that could be highly desirable for laboratory and point-of-care testing applications.Article Citation - WoS: 22Citation - Scopus: 26Magnetic Levitation Assisted Biofabrication, Culture, and Manipulation of 3d Cellular Structures Using a Ring Magnet Based Setup(Wiley, 2021) Anıl İnevi, Müge; Delikoyun, Kerem; Meşe Özçivici, Gülistan; Tekin, Hüseyin Cumhur; Özçivici, EnginDiamagnetic levitation is an emerging technology for remote manipulation of cells in cell and tissue level applications. Low-cost magnetic levitation configurations using permanent magnets are commonly composed of a culture chamber physically sandwiched between two block magnets that limit working volume and applicability. This work describes a single ring magnet-based magnetic levitation system to eliminate physical limitations for biofabrication. Developed configuration utilizes sample culture volume for construct size manipulation and long-term maintenance. Furthermore, our configuration enables convenient transfer of liquid or solid phases during the levitation. Before biofabrication, we first calibrated/ the platform for levitation with polymeric beads, considering the single cell density range of viable cells. By taking advantage of magnetic focusing and cellular self-assembly, millimeter-sized 3D structures were formed and maintained in the system allowing easy and on-site intervention in cell culture with an open operational space. We demonstrated that the levitation protocol could be adapted for levitation of various cell types (i.e., stem cell, adipocyte and cancer cell) representing cells of different densities by modifying the paramagnetic ion concentration that could be also reduced by manipulating the density of the medium. This technique allowed the manipulation and merging of separately formed 3D biological units, as well as the hybrid biofabrication with biopolymers. In conclusion, we believe that this platform will serve as an important tool in broad fields such as bottom-up tissue engineering, drug discovery and developmental biology.Article Citation - WoS: 22Citation - Scopus: 24Scaffold-Free Biofabrication of Adipocyte Structures With Magnetic Levitation(John Wiley and Sons Inc., 2021) Sarıgil, Öykü; Yalçın Özuysal, Özden; Anıl İnevi, Müge; Meşe Özçivici, Gülistan; Fıratlıgil Yıldırır, Burcu; Fıratlıgil Yıldırır, Burcu; Ünal, Yağmur Ceren; Ünal, Yağmur Ceren; Yalçın Özuysal, Özden; Özçivici, Engin; Meşe, Gülistan; Sarıgil, Öykü; Özçivici, Engin; Anıl İnevi, Müge; Meşe Özçivici, GülistanTissue engineering research aims to repair the form and/or function of impaired tissues. Tissue engineering studies mostly rely on scaffold-based techniques. However, these techniques have certain challenges, such as the selection of proper scaffold material, including mechanical properties, sterilization, and fabrication processes. As an alternative, we propose a novel scaffold-free adipose tissue biofabrication technique based on magnetic levitation. In this study, a label-free magnetic levitation technique was used to form three-dimensional (3D) scaffold-free adipocyte structures with various fabrication strategies in a microcapillary-based setup. Adipogenic-differentiated 7F2 cells and growth D1 ORL UVA stem cells were used as model cells. The morphological properties of the 3D structures of single and cocultured cells were analyzed. The developed procedure leads to the formation of different patterns of single and cocultured adipocytes without a scaffold. Our results indicated that adipocytes formed loose structures while growth cells were tightly packed during 3D culture in the magnetic levitation platform. This system has potential for ex vivo modeling of adipose tissue for drug testing and transplantation applications for cell therapy in soft tissue damage. Also, it will be possible to extend this technique to other cell and tissue types.Book Part Citation - Scopus: 15Stem Cell Culture Under Simulated Microgravity(Springer, 2020) Anıl İnevi, Müge; Sarıgil, Öykü; Kızılkaya, Melike; Meşe, Gülistan; Tekin, Hüseyin Cumhur; Özçivici, EnginChallenging environment of space causes several pivotal alterations in living systems, especially due to microgravity. The possibility of simulating microgravity by ground-based systems provides research opportunities that may lead to the understanding of in vitro biological effects of microgravity by eliminating the challenges inherent to spaceflight experiments. Stem cells are one of the most prominent cell types, due to their self-renewal and differentiation capabilities. Research on stem cells under simulated microgravity has generated many important findings, enlightening the impact of microgravity on molecular and cellular processes of stem cells with varying potencies. Simulation techniques including clinostat, random positioning machine, rotating wall vessel and magnetic levitation-based systems have improved our knowledge on the effects of microgravity on morphology, migration, proliferation and differentiation of stem cells. Clarification of the mechanisms underlying such changes offers exciting potential for various applications such as identification of putative therapeutic targets to modulate stem cell function and stem cell based regenerative medicine. © Springer Nature Switzerland AG 2020.Article Citation - WoS: 34Citation - Scopus: 43Label-Free Density-Based Detection of Adipocytes of Bone Marrow Origin Using Magnetic Levitation(Royal Society of Chemistry, 2019) Sarıgil, Öykü; Anıl İnevi, Müge; Yılmaz, Esra; Meşe, Gülistan; Tekin, Hüseyin Cumhur; Özçivici, EnginAdipocyte 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.Article Citation - WoS: 79Citation - Scopus: 94Biofabrication 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, EnginMagnetic 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.