PubMed İndeksli Yayınlar Koleksiyonu / PubMed Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7645
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Article Citation - WoS: 2Citation - Scopus: 3Dynamic Fluidic Manipulation in Microfluidic Chips With Dead-End Channels Through Spinning: the Spinochip Technology for Hematocrit Measurement, White Blood Cell Counting and Plasma Separation(Royal Soc Chemistry, 2025) Tekin, Hüseyin Cumhur; Tekin, Hüseyin Cumhur; Bicmen, Can; Tekin, H. Cumhur; 03.01. Department of Bioengineering; 03. Faculty of Engineering; 01. Izmir Institute of TechnologyCentrifugation is crucial for size and density-based sample separation, but low-volume or delicate samples suffer from loss and impurity issues during repeated spins. We introduce the "Spinochip", a novel microfluidic system utilizing centrifugal forces for efficient filling of dead-end microfluidic channels. The Spinochip enables versatile fluid manipulation with a single reservoir for both inlet and outlet functions. It expels compressed air, facilitating fluid flow, and offers programmable filling mechanisms based on the hydraulic resistance of microfluidic channels. Compatible with a basic centrifuge, it allows sequential filling, internal mixing, and collection in straight microfluidic channels by simply adjusting the spinning speed, eliminating the need for complex valving. We demonstrated the Spinochip's efficacy in blood testing, where it successfully separated blood components, such as plasma, buffy coat, and red blood cells, from a single drop using centrifugation alone. This system enabled simultaneous hematocrit (R2 >0.99) and total white blood cell (R2 >0.93) quantification within a single microfluidic channel without the need for staining or special reagents. Remarkably, the Spinochip can perform hematocrit measurements on as little as 100 nL of blood, potentially paving the way for less invasive blood analysis. This innovative approach unlocks new possibilities in microfluidics, providing precise fluidic control and centrifugation for sample volumes as small as a few nanoliters.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; Özçivici, Engin; Meşe Özçivici, Gülistan; Tekin, Hüseyin Cumhur; 03.01. Department of Bioengineering; 04.03. Department of Molecular Biology and Genetics; 03. Faculty of Engineering; 04. Faculty of Science; 01. Izmir Institute of TechnologyDiamagnetic 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: 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.Book Part Citation - WoS: 13Citation - Scopus: 15Single Cell Densitometry and Weightlessness Culture of Mesenchymal Stem Cells Using Magnetic Levitation(Humana Press, 2020) Anıl İnevi, Müge; Özçivici, Engin; Yılmaz, Esra; Sarıgil, Öykü; Sarıgil, Öykü; Tekin, Hüseyin Cumhur; Tekin, Hüseyin Cumhur; Anıl İnevi, Müge; Özçivici, Engin; 03.01. Department of Bioengineering; 01. Izmir Institute of Technology; 03. Faculty of EngineeringMagnetic levitation methodology enables density-based separation of microparticles/cells and sustains cell culture in different media. Levitation process can be accomplished via negative magnetophoresis (diamagnetophoresis), where the applied magnetic force compensates gravitational acceleration and the density of the diamagnetic object (e.g., cell) determines its levitation height. Here we describe a portable, sensitive, and cost-effective technology that uses the principles of magnetic levitation to measure single cell density and cell culture under desired conditions. © 2019, Springer Science+Business Media New York.