A novel dielectrophoresis activated cell sorter (DACS) to evaluate the apoptotic rate of K562 cells treated with arsenic trioxide (As₂O₃)

Lee, D.,Hwang, B.,Choi, Y.,Kim, B. Elsevier Sequoia 2016 Sensors and actuators. A Physical Vol.242 No.-

Recently, arsenic trioxide (As<SUB>2</SUB>O<SUB>3</SUB>) has been highlighted for use in chemotherapy drugs, and it has been reported that it can induce the apoptosis of a leukemia cell. Until now, methyl thiazol tetrazolium (MTT) assay, DNA fragmentation assay, and morphologic examination were typically employed to investigate the apoptotic rate of leukemia cell lines after being treated with arsenic trioxide. In this paper, we propose a novel dielectrophoresis activated cell sorter (DACS) to evaluate the apoptotic rate of leukemia cells. The proposed electrode arrays based DACS consists of two transparent plates with macro width. These arrays enable the improvement of throughput and achieve the minimum number of structures to enhance the performance of the sorter with respect to factors such as cell adhesion and the leaking phenomenon. In particular, to achieve high separation efficiency, five microelectrodes are repeatedly deposited on each glass plate. In order to generate a dielectrophoretic (DEP) barrier for cell separation, the microelectrodes facing each other on the two glass plates are exactly aligned in the fabrication process. To confirm the feasibility of this cell separation concept, we analyze the forces acting on the target cell, including the DEP force, hydrodynamic drag force, and gravity. In addition, we implement a simulation study for the proposed DACS with specific channel and electrode dimensions. Prior to the separation test, we select a leukemia cell (K562 cell) as our target cell and investigate the apoptotic rate of the K562 cells treated with the arsenic trioxide according to the duration of treatment. This provides us with the efficacy of As<SUB>2</SUB>O<SUB>3</SUB> for K562. Prior to the separation experiment for the efficacy evaluation, we first carry out a separation test with all live K562 cells and obtain a high separation efficiency of 94.74% with a low voltage of 7 Vp-p with 10kHz. Then, the separation efficiencies are evaluated utilizing a live/dead cell mixture according to the duration of treatment being 12 and 24h. Conclusively, the DACS achieves high separation efficiencies of 94.71% and 93.25% with the treated samples during 12 and 24h durations, respectively. Moreover the recovery rate and the throughput show competitive results of 62.5% and 17,000 cells/min.

Numerical Analysis of Dielectrophoresis-Based Microfluidic Chip with a Facing-Electrode Design for Cell Separation

Nguyen Thu Hang,Nguyen Mai Chi,Nguyen Hoang Trung,Thi Y Van Tran,Vu Ngoc Trung,Thu Hang Bui,Duc Trinh Chu,Bui Tung Thanh,Jen Chun-Ping,Quang Loc Do 한국농업기계학회 2024 바이오시스템공학 Vol.49 No.1

Purpose Circulating tumor cell separation and analysis have played a critical role in cancer diagnosis, prognosis, and treatment. In this work, we aim to design and investigate a novel biochip that integrates dielectrophoresis, microfl uidic technology to separate circulating tumor cells from blood cells. To create a dielectrophoresis-induced non-uniform electric fi eld, a facing-electrode design was proposed and utilized, in which a slanted electrode array and a simple rectangular ground electrode are placed parallel on the top and bottom parts of the microfl uidic channel, respectively. This design can reduce the particle position dependence in the microchannel and the complexity of the microfabrication process. Methods The separation process, effi ciency, and optimization of the proposed device were numerically investigated using the fi nite element method. Parametric research was conducted to comprehensively examine the impact of various operating and design factors on the cell movement and trajectories in the microfl uidic device. Results The results indicated the potential of the proposed biochip to ensure cancer cell separation from blood cells with high effi ciency, high purity in a label-free, non-invasive, easy integration, and low-cost manner. Under the optimal conditions, the separation effi ciency reached 92%, 88%, and 96% for human colon cancer cells (HT-29), red blood cells, and white blood cells, respectively. Conclusions In this study, a novel DEP-based microfl uidic chip was proposed to separate HT-29 tumor cells from blood cells and numerically investigated to verify the performance of the biochip design. Our fi ndings could provide a foundation for further theoretical and practical investigations. The proposed system can separate cancer cells from red blood cells and white blood cells as well as off ers numerous advantages, such as compact size, low voltage, high effi ciency, non-invasiveness, and label-free nature. The tumor cell enrichment platform has the potential for application in cancer detection, analysis, and assessment.

Numerical simulation-based performance improvement of the separation of circulating tumor cells from bloodstream in a microfluidic platform by dielectrophoresis

Nguyen Ngoc-Viet,Van Manh Hoang,Van Hieu Nguyen 한국유변학회 2022 Korea-Australia rheology journal Vol.34 No.4

Circulating tumor cells (CTCs) detection has become one of the promising solutions for the early diagnosis of cancers. Thus, the separation of CTCs is of great importance in biomedical applications. In addition, microfluidic technology has been an attractive approach to the manipulation of biological cells. This study presents the parametric investigations relevant to the volumetric throughput of a microfluidic platform with the dielectrophoresis (DEP)-based cell manipulation technique for the continuous CTCs separation. A low potential voltage at an appropriate frequency was applied to slanted planar electrodes to separate CTCs from normal cells in blood samples due to mainly the cell size difference. The performance of the separation process was analyzed by evaluating the cell trajectories, purity, and recovery rates. Several inlet flow rates of buff er and cell sample fluid streams were examined. Various channel configurations with different outlet and height dimensions were also investigated to enhance the isolation of CTCs. During the simulation, the size and shape of cells were assumed as fixed-sized, solid spheres. The results showed that CTCs could be separated from blood cells, including white blood cells (WBCs), red blood cells (RBCs), and platelets (PLTs) with recovery and purity factors up to 100% at the cell sample throughput of 10 μL/ min by utilizing a suitable microchannel design. The current study significantly contributes valuable insights into the design of the microchip devices to effectively and selectively isolate different cancerous cells in biofluids.

Separation of Human Breast Cancer and Epithelial Cells by Adhesion Difference in a Microfluidic Channel

Keon Woo Kwon,Sung Sik Choi,Byungkyu Kim,Se Na Lee,Sang Ho Lee,Min Cheol Park,Pilnam Kim,Sukho Park,Youngho Kim,Jungyul Park,Kahp Y. Suh 대한전자공학회 2007 Journal of semiconductor technology and science Vol.7 No.3

A simple, label-free microfluidic cell purification method is presented for separation of cancer cells by exploiting difference in cell adhesion. To maximize the adhesion difference, three types of polymeric nanostructures (50nm pillars, 50nm perpendicular and 50nm parallel lines with respect to the direction of flow) were fabricated using UVassisted capillary moulding and included inside a polydimethylsiloxane (PDMS) microfluidic channel bonded onto glass substrate. The adhesion force of human breast epithelial cells (MCF10A) and human breast carcinoma (MCF7) was measured independently by injecting each cell line into the microfluidic device followed by culture for a period of time (e.g., one, two, and three hours). Then, the cells bound to the floor of a microfluidic channel were detached by increasing the flow rate of medium in a stepwise fashion. It was found that the adhesion force of MCF10A was always higher than that of MCF cells regardless of culture time and surface nanotopography at all flow rates, resulting in a label-free detection and separation of cancer cells. For the cell types used in our study, the optimum separation was found for 2 hours culture on 50nm parallel line pattern followed by flow-induced detachment at a flow rate of 300 ㎕/min.

Separation of Human Breast Cancer and Epithelial Cells by Adhesion Difference in a Microfluidic Channel

Kwon, Keon-Woo,Choi, Sung-Sik,Kim, Byung-Kyu,Lee, Se-Na,Lee, Sang-Ho,Park, Min-Cheol,Kim, Pil-Nam,Park, Suk-Ho,Kim, Young-Ho,Park, Jun-Gyul,Suh, Kahp-Y. The Institute of Electronics and Information Engin 2007 Journal of semiconductor technology and science Vol.7 No.3

A simple, label-free microfluidic cell purification method is presented for separation of cancer cells by exploiting difference in cell adhesion. To maximize the adhesion difference, three types of polymeric nanostructures (50nm pillars, 50nm perpendicular and 50nm parallel lines with respect to the direction of flow) were fabricated using UV-assisted capillary moulding and included inside a polydimethylsiloxane (PDMS) microfluidic channel bonded onto glass substrate. The adhesion force of human breast epithelial cells (MCF10A) and human breast carcinoma (MCF7) was measured independently by injecting each cell line into the microfluidic device followed by culture for a period of time (e.g., one, two, and three hours). Then, the cells bound to the floor of a microfluidic channel were detached by increasing the flow rate of medium in a stepwise fashion. It was found that the adhesion force of MCF10A was always higher than that of MCF cells regardless of culture time and surface nanotopography at all flow rates, resulting in a label-free detection and separation of cancer cells. For the cell types used in our study, the optimum separation was found for 2 hours culture on 50nm parallel line pattern followed by flow-induced detachment at a flow rate of $300{\mu}l/min$.

Portable vibration-assisted filtration device for on-site isolation of blood cells or pathogenic bacteria from whole human blood

Kim, Yong Tae,Park, Kyun Joo,Kim, Seyl,Kim, Soon Ae,Lee, Seok Jae,Kim, Do Hyun,Lee, Tae Jae,Lee, Kyoung G. Elsevier 2018 Talanta Vol.179 No.-

<P><B>Abstract</B></P> <P>Isolation of specific cells from whole blood is important to monitor disease prognosis and diagnosis. In this study, a vibration-assisted filtration (VF) device has been developed for isolation and recovery of specific cells such as leukocytes and pathogenic bacteria from human whole blood. The VF device is composed of three layers which was fabricated using injection molding with cyclic olefin copolymer (COC) pellets consisting of: a top layer with coin-type vibration motor (Ф = 10mm), a middle plate with a 1μm or 3μm-pore filter membrane to separate of <I>Staphylococcus aureus</I> (<I>S. aureus</I>) cells or leukocytes (i.e. white blood cells) respectively, and a bottom chamber with conical-shaped microstructure. One milliliter of human whole blood was injected into a sample loading chamber using a 3μm-pore filter equipped in the VF device and the coin-type vibration motor applied external vibration force by generating a rotational fluid which enhances the filtration velocity due to the prevention of the cell clogging on the filter membrane. The effluent blood such as erythrocytes, platelet, and plasma was collected at the bottom chamber while the leukocytes were sieved by the filter membrane. The vibration-assisted leukocyte separation was able to finish within 200s while leukocyte separation took 1200s without vibration. Moreover, we successfully separated <I>S. aureus</I> from human whole blood using a 1μm-pore filter equipped VF device and it was further confirmed by genetic analysis. The proposed VF device provides an advanced cell separation platform in terms of simplicity, fast separation, and portability in the fields of point-of-care diagnostics.</P> <P><B>Highlights</B></P> <P> <UL> <LI> A vibration-assisted filtering device (VF) was developed for isolation of specific cells. </LI> <LI> 6-fold faster separation of leukocytes has been accomplished. </LI> <LI> Pathogenic bacteria can be successfully recovered from human blood. </LI> <LI> The VF device provides a cell isolation platform for on-site disease diagnostics. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

A Cell Sorting System for the Evaluation of Drug Sensitivity Using Negative Dielectrophoresis

이동규,김병규 한국정밀공학회 2015 International Journal of Precision Engineering and Vol.16 No.3

In this paper, we present a cell sorting system with vertical shaped channel based double separation modules to evaluate drugsensitivity using negative dielectrophoresis (n-DEP). Since the hydrodynamic force and n-DEP force are the main parameters thatdetermine separation efficiency, we evaluate the amounts of these forces acting on each cell. Based on simulation and theoreticalresults, separation conditions are experimentally investigated. Finally, we select an input condition of 7 Vp-p with 100 kHz and a flowrate of 20 μL·min-1 and 10 μl·min-1 in outlets A and B, respectively. To confirm the effectiveness of the sorting system, we performseparation experiments using micro particles, diameters of 10 μm. As a result, this system separate particles with 94±2% separationefficiency. To evaluate the drug sensitivity for specific cells, we select a leukemia cell line (K562) as the target cells and mitomycinC as the chemotherapy drug. Then, the apoptotic rate of K562 is investigated under various culturing times with mitomycin C. Finally,separation efficiency is evaluated by separating the live K562 from a mixture cultured for 24 hours. Conclusively this sorting systemcan separate live cells from a mixture of live and dead cells with 95±1.1% separation efficiency.

Separation of tumor cells from the peripheral blood via a novel electro hydrodynamics model

Li, Xin,Liu, Yanping,Wang, Yingcui,Zou, Caixia Techno-Press 2021 Advances in nano research Vol.10 No.6

The significant issue that has been investigated in this research due to the great clinical potential is to separate a circulating tumor cells (CTCs) from the peripheral blood and cancer treatment in advance. Nonetheless, it is difficult to detect CTCs because of the rare existence of CTCs in the middle of peripheral blood. It is found that the need of high resolution ethods is crucial because there is a similarity in size range between CTCs types such as the cells of breast cancer and the white blood cells (WBCs). This paper presents a device which can be used for tumor cells separation from the cells of blood with nonstop flow that is helped by fractionating dielectrophoresis (DEP) field-flow. The reason that leads CTCs to separate from the cells of blood is the obvious different sizes of hydrodynamics focusing and dielectrophoretic force. Numerous attempts have been made to calculate CTCs trajectories with the aid of simulating the flow speed and electric field and it reveals an accurate comparison of them with the measured results. Furthermore, the low applied voltage such 10 V_pp with which the represented device can be utilized. The high precision and efficiency of particle separation can be obtained by the device as well. According to the differences in size, this approach has various application for separation of other particles sorts. Based on our findings in this study, it is assumed that our device is beneficial for studying cancer and also has an excellent capability of separating tumor cells from blood cells.

Performance Comparison of Two Ellipse Fitting-Based Cell Separation Algorithms

Cho, Migyung The Korea Institute of Information and Commucation 2015 Journal of information and communication convergen Vol.13 No.3

Cells in a culture process transform with time and produce many overlapping cells in their vicinity. We are interested in a separation algorithm for images of overlapping cells taken using a fluorescence optical microscope system during a cell culture process. In this study, all cells are assumed to have an ellipse-like shape. For an ellipse fitting-based method, an improved least squares method is used by decomposing the design matrix into quadratic and linear parts for the separation of overlapping cells. Through various experiments, the improved least squares method (numerically stable direct least squares fitting [NSDLSF]) is compared with the conventional least squares method (direct least squares fitting [DLSF]). The results reveal that NSDLSF has a successful separation ratio with an average accuracy of 95% for two overlapping cells, an average accuracy of 91% for three overlapping cells, and about 82% accuracy for four overlapping cells.

A Role of YlBud8 in the Regulation of Cell Separation in the Yeast Yarrowia lipolytica

( Yun-qing Li ),( Qing-jie Xue ),( Yuan-yuan Yang ),( Hui Wang ),( Xiu-zhen Li ) 한국미생물 · 생명공학회 2019 Journal of microbiology and biotechnology Vol.29 No.1

The spatial landmark protein Bud8 plays a crucial role in bipolar budding in the budding yeast Saccharomyces cerevisiae. The unconventional yeast Yarrowia lipolytica can also bud in a bipolar pattern, but is evolutionarily distant from S. cerevisiae. It encodes the protein YALI0F12738p, which shares the highest amino acid sequence homology with S. cerevisiae Bud8, sharing a conserved transmembrane domain at the C-terminus. Therefore, we named it YlBud8. Deletion of YlBud8 in Y. lipolytica causes cellular separation defects, resulting in budded cells remaining linked with one another as cell chains or multiple buds from a single cell, which suggests that YlBud8 may play an important role in cell separation, which is distinct from the function of Bud8 in S. cerevisiae. We also show that the YlBud8-GFP fusion protein is located at the cell membrane and enriched in the bud cortex, which would be consistent with a role in the regulation of cell separation. The coiled-coil domain at the Nterminus of YlBud8 is important to the correct localization and function of YlBud8, as truncated proteins that do not contain the coiled-coil domain cannot rescue the defects observed in Ylbud8Δ. This finding suggests that a new signaling pathway controlled by YlBud8 via regulation of cell separation may exist in Y. lipolytica.