1
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Yang X, Zhong Z. A novel technique to fabricate magnetic polydimethylsiloxane micropillar. J Appl Polym Sci 2021. [DOI: 10.1002/app.50460] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Xiaoming Yang
- School of Mechanical and Aerospace Engineering Nanyang Technological University Singapore
| | - Zhaowei Zhong
- School of Mechanical and Aerospace Engineering Nanyang Technological University Singapore
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2
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Hernández-Castro JA, Li K, Daoud J, Juncker D, Veres T. Two-level submicron high porosity membranes (2LHPM) for the capture and release of white blood cells (WBCs). LAB ON A CHIP 2019; 19:589-597. [PMID: 30648711 DOI: 10.1039/c8lc01256c] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
A method modifying a vacuum-assisted UV micro-molding (VAUM) process is proposed for the fabrication of polymer two-level submicron high porosity membranes (2LHPM). The modified process allows for the fabrication of robust, large-area membranes over 5 × 5 cm2 with a hierarchical architecture made from a 200 nm-thick layer having submicron level pores (as small as 500 nm) supported by a 20 μm-thick layer forming a microporous structure with 10-15 μm diameter pores. The fabricated freestanding membranes are flexible and mechanically robust enough for post manipulation and filtration of cell samples. Very high white blood cell (WBC) capture efficiencies (≈97%) from healthy blood samples after red blood cell (RBC) lysis are demonstrated using a 3D-printed filter cartridge incorporated within these 2LHPM. A high release efficiency of ≈95% is also proved using the same setup. Finally, on-filter multistep immunostaining of captured cells is also shown.
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3
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Dalili A, Samiei E, Hoorfar M. A review of sorting, separation and isolation of cells and microbeads for biomedical applications: microfluidic approaches. Analyst 2019; 144:87-113. [DOI: 10.1039/c8an01061g] [Citation(s) in RCA: 145] [Impact Index Per Article: 29.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
We have reviewed the microfluidic approaches for cell/particle isolation and sorting, and extensively explained the mechanism behind each method.
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Affiliation(s)
- Arash Dalili
- The University of British
- School of Engineering
- Kelowna
- Canada V1 V 1 V7
| | - Ehsan Samiei
- University of Victoria
- Department of Mechanical Engineering
- Victoria
- Canada
| | - Mina Hoorfar
- The University of British
- School of Engineering
- Kelowna
- Canada V1 V 1 V7
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4
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Son YJ, Kang J, Kim HS, Yoo HS. Electrospun Nanofibrous Sheets for Selective Cell Capturing in Continuous Flow in Microchannels. Biomacromolecules 2016; 17:1067-74. [DOI: 10.1021/acs.biomac.5b01689] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Young Ju Son
- Department of Medical Biomaterials Engineering and §Institute of Bioscience
and Biotechnology, Kangwon National University, Chuncheon 200-701, Republic of Korea
| | - Jihyun Kang
- Department of Medical Biomaterials Engineering and §Institute of Bioscience
and Biotechnology, Kangwon National University, Chuncheon 200-701, Republic of Korea
| | - Hye Sung Kim
- Department of Medical Biomaterials Engineering and §Institute of Bioscience
and Biotechnology, Kangwon National University, Chuncheon 200-701, Republic of Korea
| | - Hyuk Sang Yoo
- Department of Medical Biomaterials Engineering and §Institute of Bioscience
and Biotechnology, Kangwon National University, Chuncheon 200-701, Republic of Korea
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5
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Tsai TN, Lee TY, Liu MS, Chuang IC, Lu MC, Dong HP, Lue SI, Yang RC. Release of endogenous heat shock protein 72 on the survival of sepsis in rats. J Surg Res 2015; 198:165-74. [PMID: 26073348 DOI: 10.1016/j.jss.2015.05.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2015] [Revised: 04/17/2015] [Accepted: 05/01/2015] [Indexed: 11/24/2022]
Abstract
BACKGROUND This study was undertaken to clarify the role of extracellular heat shock protein 72 on the survival of sepsis and to determine possible factor(s) that may be responsible for it. MATERIALS AND METHODS Sepsis was induced by cecal ligation and puncture. Changes in serum levels of heat shock protein (Hsp72) and cytokines were determined during sepsis, and the results were correlated with the survival. Effects of heat pretreatment on Hsp72 expression in septic rat leukocytes and those of septic rat serum, lipopolysaccharide (LPS), and certain cytokines on the release of Hsp72 in macrophage NR8383 cells were determined. RESULTS Circulating Hsp72 levels were increased during the progress of sepsis (0, 5.5, 6.5, 10, and 6.5 ng/mL at 0, 3, 6, 9, and 18 h after cecal ligation and puncture, respectively) and the increases were correlated positively with survival rates. LPS triggered the release of Hsp72 in heat pretreated animals. Heat pretreatment increased Hsp72 expression in nonsepsis (+535%, P < 0.01) and sepsis (+116%, P<0.01%) rat leukocytes. Incubation of sepsis rat serum with NR8383 cells increased levels of extracellular heat shock protein 72 in cultured medium. Cytokine profiling revealed that among the 19 cytokines screened, four of them were increased as follows: cytokine-induced neutrophil chemoattractant 3 (+211.3%, P < 0.05), interleukin 10 (+147%, P < 0.05), MCP-1 (+49.6%, P < 0.05), and tumor necrosis factor alpha (+51.8%, P < 0.05). MCP-1 and LPS were capable of releasing Hsp72 from NR8383 cells. CONCLUSIONS These results demonstrate that the increases in the levels of circulating Hsp72 had a beneficial effect in improving animal survival during the progress of sepsis. The increases in circulating Hsp72 may be mediated via MCP-1 and/or LPS.
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Affiliation(s)
- Tsen-Ni Tsai
- Graduate Institute of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Tzu-Ying Lee
- Graduate Institute of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Maw-Shung Liu
- Graduate Institute of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan; Department of Physiology, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - I-Chun Chuang
- Department of Respiratory Therapy, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Mei-Chin Lu
- Graduate Institute of Marine Biotechnology, National Dong Hwa University, Pingtung, Taiwan
| | - Huei-Ping Dong
- Department of Physical Therapy, Fooyin University, Kaohsiung, Taiwan
| | - Sheng-I Lue
- Department of Physiology, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Rei-Chen Yang
- Graduate Institute of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan; Department of Pediatrics, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan; Department of Pediatrics, Changhua Christian Hospital, Changhua, Taiwan.
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6
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Lee DW, Choi YS, Seo YJ, Lee MY, Jeon SY, Ku B, Nam DH. High-throughput, miniaturized clonogenic analysis of a limiting dilution assay on a micropillar/microwell chip with brain tumor cells. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2014; 10:5098-5105. [PMID: 25227876 DOI: 10.1002/smll.201401074] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/18/2014] [Revised: 06/30/2014] [Indexed: 06/03/2023]
Abstract
The limiting dilution assay (LDA) is a clonogenic drug efficacy test designed to determine a value for drug efficacy based on an all-or-none (positive or negative) response within replicates. It also attempts to calculate minimum cell numbers for cells to form colony in each drugged conditions, wherein a large value implies high drug efficacy (as a large number of extant cells are required to start a colony). However, traditional LDAs are time-consuming to set up, often requiring many replicates for statistical analysis, and manual colony identification under a microscope to determine a positive or negative response is tedious and is susceptible to human error. To address these issues, a high-throughput miniaturized LDA assay is developed using a micropillar/microwell chip platform using an automatic colony identification method. Three glioblastoma multiforme (GBM) brain tumor isolates (448T, 464T, and 775T) are used to test this new assay, using the c-Met kinase inhibitors SU11274 and PHA665752 as the target drugs. The results show that the minimum cell number of 775T is larger than that of the other two cell types (SU11274 and PHA665752) in both the sampled drugs, a result that is in good agreement with the results of previous conventional experiments using 96 well plates.
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Affiliation(s)
- Dong Woo Lee
- Central R & D Institute, Samsung Electro-mechanics Co, Suwon, Republic of Korea
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Abstract
Despite huge efforts in sample analysis, the measurement of marker nucleic acids within tissues remains largely nonquantitative. Gene analyses have benefited from sensitivity gains through in vitro gene amplification, including PCR. However, whilst these processes are intrinsically suited to highly reproducible, accurate and precise gene measurement, the term semiquantitative analysis is still commonly used, suggesting that other fundamental limitations preclude a generic quantitative basis to gene analysis. The most poorly defined aspect of gene analysis relates to the sample itself. The amount of cells and, particularly, cell subtype composition are rarely annotated before analysis; indeed, they are often extrapolated after analysis. To advance our understanding of pathogenesis, assay formats will benefit from resembling the dimensions of the cell, to assist in the analysis of cellular components of tissue complexes. This review is partly a perspective on how current miniaturization technologies, in association with molecular biology, microfluidics and surface chemistries, may evolve from the parts of a paradigm to enable the unambiguous quantitative analysis of complex biologic matter.
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Affiliation(s)
- Philip J R Day
- The University of Manchester, Centre for Integrated Genomic Medical Research (CIGMR), Stopford Building, Oxford Road, Manchester, M13 9PT, UK.
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8
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Liu C, Mauk M, Gross R, Bushman FD, Edelstein PH, Collman RG, Bau HH. Membrane-based, sedimentation-assisted plasma separator for point-of-care applications. Anal Chem 2013; 85:10463-70. [PMID: 24099566 PMCID: PMC3897712 DOI: 10.1021/ac402459h] [Citation(s) in RCA: 88] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Often, high-sensitivity, point-of-care (POC) clinical tests, such as HIV viral load, require large volumes of plasma. Although centrifuges are ubiquitously used in clinical laboratories to separate plasma from whole blood, centrifugation is generally inappropriate for on-site testing. Suitable alternatives are not readily available to separate the relatively large volumes of plasma from milliliters of blood that may be needed to meet stringent limit-of-detection specifications for low-abundance target molecules. We report on a simple-to-use, low-cost, pump-free, membrane-based, sedimentation-assisted plasma separator capable of separating a relatively large volume of plasma from undiluted whole blood within minutes. This plasma separator consists of an asymmetric, porous, polysulfone membrane housed in a disposable chamber. The separation process takes advantage of both gravitational sedimentation of blood cells and size exclusion-based filtration. The plasma separator demonstrated a "blood in-plasma out" capability, consistently extracting 275 ± 33.5 μL of plasma from 1.8 mL of undiluted whole blood within less than 7 min. The device was used to separate plasma laden with HIV viruses from HIV virus-spiked whole blood with recovery efficiencies of 95.5% ± 3.5%, 88.0% ± 9.5%, and 81.5% ± 12.1% for viral loads of 35,000, 3500, and 350 copies/mL, respectively. The separation process is self-terminating to prevent excessive hemolysis. The HIV-laden plasma was then injected into our custom-made microfluidic chip for nucleic acid testing and was successfully subjected to reverse-transcriptase loop-mediated isothermal amplification (RT-LAMP), demonstrating that the plasma is sufficiently pure to support high-efficiency nucleic acid amplification.
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Affiliation(s)
- Changchun Liu
- Department of Mechanical Engineering and Applied Mechanics, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Michael Mauk
- Department of Mechanical Engineering and Applied Mechanics, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Robert Gross
- Center for Clinical Epidemiology and Biostatistics, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
- Department of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Frederic D. Bushman
- Department of Microbiology, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Paul H. Edelstein
- Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Ronald G. Collman
- Department of Microbiology, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
- Department of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Haim H. Bau
- Department of Mechanical Engineering and Applied Mechanics, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
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9
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Glynn M, Kirby D, Chung D, Kinahan DJ, Kijanka G, Ducrée J. Centrifugo-Magnetophoretic Purification of CD4+ Cells from Whole Blood Toward Future HIV/AIDS Point-of-Care Applications. ACTA ACUST UNITED AC 2013; 19:285-96. [DOI: 10.1177/2211068213504759] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2013] [Indexed: 11/17/2022]
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10
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Warkiani ME, Bhagat AAS, Khoo BL, Han J, Lim CT, Gong HQ, Fane AG. Isoporous micro/nanoengineered membranes. ACS NANO 2013; 7:1882-1904. [PMID: 23442009 DOI: 10.1021/nn305616k] [Citation(s) in RCA: 79] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Isoporous membranes are versatile structures with numerous potential and realized applications in various fields of science such as micro/nanofiltration, cell separation and harvesting, controlled drug delivery, optics, gas separation, and chromatography. Recent advances in micro/nanofabrication techniques and material synthesis provide novel methods toward controlling the detailed microstructure of membrane materials, allowing fabrication of membranes with well-defined pore size and shape. This review summarizes the current state-of-the-art for isoporous membrane fabrication using different techniques, including microfabrication, anodization, and advanced material synthesis. Various applications of isoporous membranes, such as protein filtration, pathogen isolation, cell harvesting, biosensing, and drug delivery, are also presented.
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Affiliation(s)
- Majid Ebrahimi Warkiani
- BioSystems and Micromechanics (BioSyM) IRG, Singapore-MIT Alliance for Research and Technology (SMART) Centre, Singapore.
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12
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Alvankarian J, Bahadorimehr A, Yeop Majlis B. A pillar-based microfilter for isolation of white blood cells on elastomeric substrate. BIOMICROFLUIDICS 2013; 7:14102. [PMID: 24403994 PMCID: PMC3555971 DOI: 10.1063/1.4774068] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/05/2012] [Accepted: 12/17/2012] [Indexed: 05/12/2023]
Abstract
Our goal is to design, fabricate, and characterize a pillar-based microfluidic device for size-based separation of human blood cells on an elastomeric substrate with application in the low-cost rapid prototyping of lab-chip devices. The single inlet single outlet device is using parallel U-shape arrays of pillars with cutoff size of 5.5 μm for trapping white blood cells (WBCs) in a pillar chamber with internal dead-volume of less than 1.0 μl. The microstructures are designed to limit the elastomeric deformation against fluid pressures. Numerical analysis showed that at maximum pressure loss of 15 kPa which is lower than the device conformal bonding strength, the pillar elastomeric deformation is less than 5% for flow rates of up to 1.0 ml min(-1). Molding technique was employed for device prototyping using polyurethane methacrylate (PUMA) resin and polydimethylsiloxane (PDMS) mold. Characterization of the dual-layer device with beads and blood samples is performed. Tests with blood injection showed that ∼18%-25% of WBCs are trapped and ∼84%-89% of red blood cells (RBCs) are passed at flow rates of 15-50 μl min(-1) with a slight decrease of WBCs trap and improve of the RBCs pass at higher flow rates. Similar results were obtained by separation of mixed microspheres of different size injected at flow rates of up to 400 μl min(-1). Tests with blood samples stained by fluorescent gel demonstrated that the WBCs are accumulated in the arrays of pillars that later end up to blockage of the device. Filtration results of using elastomeric substrate present a good consistency with the trend of separation efficiencies of the similar silicon-based filters.
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Affiliation(s)
- Jafar Alvankarian
- Institute of Microengineering and Nanoelectronics, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor, Malaysia
| | - Alireza Bahadorimehr
- Institute of Microengineering and Nanoelectronics, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor, Malaysia
| | - Burhanuddin Yeop Majlis
- Institute of Microengineering and Nanoelectronics, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor, Malaysia
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13
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Wu L, Guan G, Hou HW, Bhagat AAS, Han J. Separation of Leukocytes from Blood Using Spiral Channel with Trapezoid Cross-Section. Anal Chem 2012; 84:9324-31. [DOI: 10.1021/ac302085y] [Citation(s) in RCA: 160] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Lidan Wu
- Department of Biological Engineering, Massachusetts Institute of Technology, United States
- Research Laboratory of Electronics, Massachusetts Institute of Technology, United States
| | - Guofeng Guan
- Department of Mechanical Engineering, National University of Singapore, Singapore
- Biosystems and Micromechanics
IRG, Singapore-MIT Alliance for Research and Technology (SMART), Singapore
| | - Han Wei Hou
- Research Laboratory of Electronics, Massachusetts Institute of Technology, United States
| | - Ali Asgar. S. Bhagat
- Biosystems and Micromechanics
IRG, Singapore-MIT Alliance for Research and Technology (SMART), Singapore
| | - Jongyoon Han
- Department of Biological Engineering, Massachusetts Institute of Technology, United States
- Biosystems and Micromechanics
IRG, Singapore-MIT Alliance for Research and Technology (SMART), Singapore
- Research Laboratory of Electronics, Massachusetts Institute of Technology, United States
- Department of Electrical Engineering
and Computer Science, Massachusetts Institute of Technology, United States
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14
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Abstract
The field of microfluidics has exploded in the past decade, particularly in the area of chemical and biochemical analysis systems. Borrowing technology from the solid-state electronics industry and the production of microprocessor chips, researchers working with glass, silicon, and polymer substrates have fabricated macroscale laboratory components in miniaturized formats. These devices pump nanoliter volumes of liquid through micrometer-scale channels and perform complex chemical reactions and separations. The detection of reaction products is typically done fluorescently with off-chip optical components, and the analysis time from start to finish can be significantly shorter than that of conventional techniques. In this review we describe these microfluidic analysis systems, from the original continuous flow systems relying on electroosmotic pumping for liquid motion to the large diversity of microarray chips currently in use to the newer droplet-based devices and segmented flow systems. Although not currently widespread, microfluidic systems have the potential to become ubiquitous.
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Affiliation(s)
- Eric Livak-Dahl
- Department of Chemical Engineering, University of Michigan, Ann Arbor, MI 48109, USA.
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15
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Hosokawa M, Asami M, Nakamura S, Yoshino T, Tsujimura N, Takahashi M, Nakasono S, Tanaka T, Matsunaga T. Leukocyte counting from a small amount of whole blood using a size-controlled microcavity array. Biotechnol Bioeng 2012; 109:2017-24. [PMID: 22367741 DOI: 10.1002/bit.24471] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2011] [Revised: 01/31/2012] [Accepted: 02/06/2012] [Indexed: 12/21/2022]
Abstract
Absolute counting of total leukocytes or specific subsets within small amounts of whole blood is difficult due to a lack of techniques that enable separation of all leukocytes from limited amounts of whole blood. In this study, a microfluidic device equipped with a size-controlled microcavity array for highly efficient separation of leukocytes from submicroliters of whole blood was developed. The microcavity array can separate leukocytes from whole blood based on differences in the size and deformability between leukocytes and other blood cells. Leukocytes recovered on aligned microcavities were continuously processed for image-based immunophenotypic analysis. Our device successfully recovered over 90% of leukocytes in 1 µL of whole blood without pretreatment such as density gradient centrifugation or erythrocyte lysis. In addition, the proposed system successfully performed absolute enumeration of human CD4(+) and CD8(+) leukocytes from 1 µL of whole blood, and the obtained data showed good correlation with conventional flow cytometric analysis. Our microfluidic device has great potential as a tool for a point-of-care leukocyte analysis system.
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Affiliation(s)
- Masahito Hosokawa
- Division of Biotechnology and Life Science, Institute of Engineering, Tokyo University of Agriculture and Technology, Koganei, Tokyo 184-8588, Japan
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16
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Ng CKM, Chong EYW, Roy VAL, Cheung KMC, Yeung KWK, Yu KN. Fabrication of micropillar substrates using replicas of alpha-particle irradiated and chemically etched PADC films. Appl Radiat Isot 2011; 70:1432-5. [PMID: 22130471 DOI: 10.1016/j.apradiso.2011.11.019] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2011] [Accepted: 11/06/2011] [Indexed: 10/15/2022]
Abstract
We proposed a simple method to fabricate micropillar substrates. Polyallyldiglycol carbonate (PADC) films were irradiated by alpha particles and then chemically etched to form a cast with micron-scale spherical pores. A polydimethylsiloxane (PDMS) replica of this PADC film gave a micropillar substrate with micron-scale spherical pillars. HeLa cells cultured on such a micropillar substrate had significantly larger percentage of cells entering S-phase, attached cell numbers and cell spreading areas.
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Affiliation(s)
- C K M Ng
- Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon Tong, Hong Kong
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Park S, Zhang Y, Lin S, Wang TH, Yang S. Advances in microfluidic PCR for point-of-care infectious disease diagnostics. Biotechnol Adv 2011; 29:830-9. [PMID: 21741465 DOI: 10.1016/j.biotechadv.2011.06.017] [Citation(s) in RCA: 218] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2011] [Revised: 05/14/2011] [Accepted: 06/22/2011] [Indexed: 12/20/2022]
Abstract
Global burdens from existing or emerging infectious diseases emphasize the need for point-of-care (POC) diagnostics to enhance timely recognition and intervention. Molecular approaches based on PCR methods have made significant inroads by improving detection time and accuracy but are still largely hampered by resource-intensive processing in centralized laboratories, thereby precluding their routine bedside- or field-use. Microfluidic technologies have enabled miniaturization of PCR processes onto a chip device with potential benefits including speed, cost, portability, throughput, and automation. In this review, we provide an overview of recent advances in microfluidic PCR technologies and discuss practical issues and perspectives related to implementing them into infectious disease diagnostics.
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Affiliation(s)
- Seungkyung Park
- Department of Emergency Medicine, Johns Hopkins University, Baltimore, MD 21205, USA
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Baker DW, Liu X, Weng H, Luo C, Tang L. Fibroblast/fibrocyte: surface interaction dictates tissue reactions to micropillar implants. Biomacromolecules 2011; 12:997-1005. [PMID: 21332193 DOI: 10.1021/bm1013487] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Micropillar technology has shown great promise for medical implants or sensors in recent years. To study the influence of surface topography on cellular responses, polydimethylsiloxane (PDMS) micropillar arrays with pillar spacing (20-70 μm) and height (14-25 μm) have been fabricated. The influence of micropillar arrays on cellular behavior was tested both in vitro and in vivo. Interestingly, in vitro, we observe a distinct response for 3T3 fibroblasts and RAW 264.7 macrophages to the topographical cues tested. Attachment and proliferation of fibroblasts was substantially enhanced by increasing pillar height, whereas macrophage adherence is significantly diminished by reduced pillar spacing. When implanted in the subcutaneous cavity of BALB/c mice for 14 days, we find a prevailing trend with capsule cell density and capsule thickness increasing, as both pillar height and spacing rise. Collagen deposition and neoangiogenesis, two pivotal factors in granulation tissue maturation, are also observed to have a stronger response to the increase in both pillar height and spacing. In contradiction to our original hypothesis, we observed that fibroblasts rather than macrophages are a key contributor to the in vivo outcome of micropillar arrays. Investigation into fibroblast activation, however, revealed that recruited fibrocytes, rather than resident fibroblasts, correspond to the in vivo outcome. The results from this work support the critical and often overlooked role of fibrocytes in tissue response to biomaterial implants with varying topography.
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Affiliation(s)
- David W Baker
- Bioengineering Department and Mechanical, University of Texas, Arlingto, Texas 76019-0138, United States
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20
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Zhang C, Xing D. Single-Molecule DNA Amplification and Analysis Using Microfluidics. Chem Rev 2010; 110:4910-47. [DOI: 10.1021/cr900081z] [Citation(s) in RCA: 115] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Chunsun Zhang
- MOE Key Laboratory of Laser Life Science & Institute of Laser Life Science, College of Biophotonics, South China Normal University, Guangzhou 510631, China
| | - Da Xing
- MOE Key Laboratory of Laser Life Science & Institute of Laser Life Science, College of Biophotonics, South China Normal University, Guangzhou 510631, China
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21
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Separation of model mixtures of epsilon-globin positive fetal nucleated red blood cells and anucleate erythrocytes using a microfluidic device. J Chromatogr A 2010; 1217:1862-6. [PMID: 20144459 DOI: 10.1016/j.chroma.2010.01.065] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2009] [Revised: 01/19/2010] [Accepted: 01/20/2010] [Indexed: 11/20/2022]
Abstract
Microfluidic devices are capable of separating microparticles and cells. We developed and tested the efficiency of silicon cross-flow microfilters for the separation of primitive fetal nucleated red blood cells (FNRBCs) and adult anucleate red blood cell (AARBCs) from model mixtures. Stepwise improvements over three generations of device design resulted in an increasing trend in the recovery of FNRBCs. We obtained a recovery of FNRBCs (74.0+/-6.3%, p<0.05, n=5) using the third generation device, with a depletion of 46.5+/-3.2% AARBCs from the cell mixture. The purity of FNRBCs in the enriched fraction was enhanced by a factor of 1.7-fold.
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Quang LX, Lim C, Seong GH, Choo J, Do KJ, Yoo SK. A portable surface-enhanced Raman scattering sensor integrated with a lab-on-a-chip for field analysis. LAB ON A CHIP 2008; 8:2214-9. [PMID: 19023489 DOI: 10.1039/b808835g] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
An integrated real-time sensing system that uses a portable Raman spectrometer and a micropillar array chip has been developed for field analysis. The problem of poor detection sensitivity, caused by miniaturization in the portable Raman spectrometer, was overcome by using the surface-enhanced Raman scattering (SERS) technique. The problem of poor reproducibility in the SERS detection, caused by different particle sizes and inhomogeneous degrees of aggregation, was also overcome by using continuous flow and homogeneous mixing between the analytes and nanocolloidal silver in a micropillar array microfluidic chip. Two hazardous materials, dipicolinic acid and malachite green, were quantitatively analysed using our integrated portable Raman sensor system. The observed limit of detection was estimated to be 200 ppb and 500 ppb, respectively. Our proposed analytical method, using a micropillar array PDMS chip and a portable SERS system, offers a rapid and reproducible trace detection capability for hazardous materials in the field.
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Affiliation(s)
- Ly Xuan Quang
- Department of Applied Chemistry, Hanyang University, Ansan, 426-791, South Korea
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Affiliation(s)
- Paul Yager
- Department of Bioengineering, University of Washington, Seattle, Washington 98195-5061;
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Chen X, Cui DF, Liu CC. On-line cell lysis and DNA extraction on a microfluidic biochip fabricated by microelectromechanical system technology. Electrophoresis 2008; 29:1844-51. [PMID: 18393339 DOI: 10.1002/elps.200700551] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Integrating cell lysis and DNA purification process into a micrototal analytical system (microTAS) is one critical step for the analysis of nucleic acids. On-chip cell lysis based on a chemical method is realized by sufficient blend of blood sample and the lyzing reagent. In this paper two mixing models, T-type mixing model and sandwich-type mixing model, are proposed and simulation of those models is conducted. Result of simulation shows that the sandwich-type mixing model with coiled channel performs best and this model is further used to construct the microfluidic biochip for on-line cell lysis and DNA extraction. The result of simulation is further verified by experiments. It asserts that more than 80% mixing of blood sample and lyzing reagent which guarantees that completed cell lysis can be achieved near the inlet location when the cell/buffer velocity ratio is less than 1:5. After cell lysis, DNA extraction by means of a solid-phase method is implemented by using porous silicon matrix which is integrated in the biochip. During continuous flow process in the microchip, rapid cell lysis and PCR-amplifiable genomic DNA purification can be achieved within 20 min. The potential of this microfluidic biochip is illustrated by pretreating a whole blood sample, which shows the possibility of integration of sample preparation, PCR, and separation on a single device to work as portable point-of-care medical diagnostic system.
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Affiliation(s)
- Xing Chen
- State Key Laboratory of Transducer Technology, Institute of Electronics, Chinese Academy of Sciences, Beijing, P. R. China.
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25
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Dauriac V, Descroix S, Chen Y, Peltre G, Sénéchal H. Isoelectric focusing in an ordered micropillar array. Electrophoresis 2008; 29:2945-52. [DOI: 10.1002/elps.200800052] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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26
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27
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Pipper J, Zhang Y, Neuzil P, Hsieh TM. Clockwork PCR Including Sample Preparation. Angew Chem Int Ed Engl 2008; 47:3900-4. [DOI: 10.1002/anie.200705016] [Citation(s) in RCA: 98] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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28
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Ji HM, Samper V, Chen Y, Heng CK, Lim TM, Yobas L. Silicon-based microfilters for whole blood cell separation. Biomed Microdevices 2008; 10:251-7. [PMID: 17914675 DOI: 10.1007/s10544-007-9131-x] [Citation(s) in RCA: 152] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
This paper reports on the comparison analysis of four main types of silicon-based microfilter for isolation of white blood cells (WBCs) from red blood cells (RBCs) in a given whole blood. The microfilter designs, namely, weir, pillar, crossflow, and membrane, all impose the same cut-off size of 3.5 mum to selectively trap WBCs. Using human whole blood, the microfilters have been characterized and compared for their blood handling capacity, WBCs trapping efficiency and RBCs passing efficiency. Based on the experimental results, the crossflow microfilter is superior and can be integrated with downstream components for on-chip genomic analysis.
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Affiliation(s)
- Hong Miao Ji
- Institute of Microelectronics, Singapore, Singapore
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29
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Hindson BJ, Gutierrez DM, Ness KD, Makarewicz AJ, Metz TR, Setlur US, Benett WB, Loge JM, Colston, Jr. BW, Francis PS, Barnett NW, Dzenitis JM. Development of an automated DNA purification module using a micro-fabricated pillar chip. Analyst 2008; 133:248-55. [DOI: 10.1039/b713332d] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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30
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Abstract
This review describes recent work in cell separation using micro- and nanoscale technologies. These devices offer several advantages over conventional, macroscale separation systems in terms of sample volumes, low cost, portability, and potential for integration with other analytical techniques. More importantly, and in the context of modern medicine, these technologies provide tools for point-of-care diagnostics, drug discovery, and chemical or biological agent detection. This review describes work in five broad categories of cell separation based on (1) size, (2) magnetic attraction, (3) fluorescence, (4) adhesion to surfaces, and (5) new emerging technologies. The examples in each category were selected to illustrate separation principles and technical solutions as well as challenges facing this rapidly emerging field.
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Affiliation(s)
- Milica Radisic
- Institute of Biomaterials and Biomedical Engineering, University of Toronto, Ontario, Canada.
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31
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Qu BY, Wu ZY, Tian XX, Chen K, Fang F. Optimization of direct whole blood PCR amplification with applications on a static thermostat chip. Anal Bioanal Chem 2007; 389:1499-504. [PMID: 17849104 DOI: 10.1007/s00216-007-1549-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2007] [Revised: 08/01/2007] [Accepted: 08/07/2007] [Indexed: 10/22/2022]
Abstract
In this paper, direct whole blood PCR amplifications on a static chip thermostat without sample purifications are demonstrated; in these amplifications, problems such as cross-interferences and contaminations could be avoided. The amplification conditions, such as the compositions of reagents and thermal programs, were investigated systematically by a GeneAmp PCR system with a native p53 gene segment (about 543 bp) of human genome and an exterior lambda DNA segment (about 500 bp) as targets. Direct amplifications of p53 and K-ras (about 157 bp) gene segments from 0.5 microL blood samples were successfully demonstrated by a static PCR chip with an indium tin oxide glass substrate. The chip thermostat has a typical size of 25 mm x 25 mm, and a polyethylene tube was used as the PCR vial on the glass surface of the chip. Fuzzy proportional integration-differentiation algorithms were adopted in temperature controls of the chip with an aid of a micro-Pt100 sensor. In the direct PCR with the thermostat chip, the whole process only involves automatic thermal programs. This work demonstrated that a chip PCR for field test without desktop facilities is possible either for a point of care test or for forensic analysis.
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Affiliation(s)
- Bai-Yan Qu
- Research Center of Analytical Science, Northeastern University, Wenhua Road 3-11, Shenyang 110004, China
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32
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Zhang C, Xing D. Miniaturized PCR chips for nucleic acid amplification and analysis: latest advances and future trends. Nucleic Acids Res 2007; 35:4223-37. [PMID: 17576684 PMCID: PMC1934988 DOI: 10.1093/nar/gkm389] [Citation(s) in RCA: 235] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2006] [Revised: 04/28/2007] [Accepted: 04/29/2007] [Indexed: 01/01/2023] Open
Abstract
The possibility of performing fast and small-volume nucleic acid amplification and analysis on a single chip has attracted great interest. Devices based on this idea, referred to as micro total analysis, microfluidic analysis, or simply 'Lab on a chip' systems, have witnessed steady advances over the last several years. Here, we summarize recent research on chip substrates, surface treatments, PCR reaction volume and speed, architecture, approaches to eliminating cross-contamination and control and measurement of temperature and liquid flow. We also discuss product-detection methods, integration of functional components, biological samples used in PCR chips, potential applications and other practical issues related to implementation of lab-on-a-chip technologies.
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Affiliation(s)
| | - Da Xing
- MOE Key Laboratory of Laser Life Science & Institute of Laser Life Science, South China Normal University, Guangzhou 510631, China
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VanDelinder V, Groisman A. Perfusion in Microfluidic Cross-Flow: Separation of White Blood Cells from Whole Blood and Exchange of Medium in a Continuous Flow. Anal Chem 2007; 79:2023-30. [PMID: 17249639 DOI: 10.1021/ac061659b] [Citation(s) in RCA: 104] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
We describe a microfluidic technique for separation of particles and cells and a device that employs this technique to separate white blood cells (WBC) from whole human blood. The separation is performed in cross-flow in an array of microchannels with a deep main channel and large number of orthogonal, shallow side channels. As a suspension of particles advances through the main channel, a perfusion flow through the side channels gradually exchanges the medium of the suspension and washes away particles that are sufficiently small to enter the shallow side channels. The microfluidic device is tested with a suspension of polystyrene beads and is shown to efficaciously exchange the carrier medium while retaining all beads. In tests with whole human blood, the device is shown to reduce the content of red blood cells (RBC) by a factor of approximately 4000 with retention of 98% of WBCs. The ratio between WBCs and RBCs reached at an outlet of the device is 2.4 on average. The device is made of a single cast of poly(dimethylsiloxane) sealed with a cover glass and is simple to fabricate. The proposed technique of separation by perfusion in continuous cross-flow could be used to enrich rare populations of cells based on differences in size, shape, and deformability.
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Affiliation(s)
- Virginia VanDelinder
- Department of Physics, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093, USA
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34
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Nissilä T, Sainiemi L, Sikanen T, Kotiaho T, Franssila S, Kostiainen R, Ketola RA. Silicon micropillar array electrospray chip for drug and biomolecule analysis. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2007; 21:3677-3682. [PMID: 17957810 DOI: 10.1002/rcm.3266] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
We have developed a lidless micropillar array electrospray ionization chip (microPESI) combined with mass spectrometry (MS) for analysis of drugs and biomolecules. The microPESI chip, made of silicon, contains a sample introduction spot for a liquid sample, an array of micropillars (diameter, height, and distance between pillars in the range of 15-200, 20-40, and 2-80 microm, respectively), and a sharpened tip for direct electrospray formation. The microchips were fabricated using deep reactive ion etching (DRIE) which results in accurate dimensional control. The chip, providing a reliable open-channel filling structure based on capillary forces and a electrospray emitter tip for ionization, allows an easy operation and reliable, non-clogging liquid transfer. The microPESI chip can be used for a fast analysis using single sampling or for continuous infusion measurements using a syringe pump for sample introduction. The microPESI-MS shows high sensitivity, with limit of detection 30 pmol/L (60 amol or 28 fg) for verapamil measured with tandem mass spectrometry (MS/MS) and using a sample volume of 2.5 microL. The system shows also good quantitative linearity (r2 > 0.99) with linear dynamic range of at least six orders of magnitude and good ion current stability (standard deviation <5%) in 1-h continuous flow measurement. The microPESI-MS is shown to be a very potential method for direct analysis of drugs and biomolecules.
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Affiliation(s)
- Teemu Nissilä
- Division of Pharmaceutical Chemistry, P.O. Box 56, FI-00014 University of Helsinki, Finland
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35
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Liu RH, Lee AP. PCR in Integrated Microfluidic Systems. INTEGRATED BIOCHIPS FOR DNA ANALYSIS 2007. [PMCID: PMC7124038 DOI: 10.1007/978-0-387-76759-8_7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Miniaturized integrated DNA analysis systems offer the potential to provide unprecedented advances in cost and speed relative to current benchtop-scale instrumentation by allowing rapid bioanalysis assays to be performed in a portable self contained device format that can be inexpensively mass-produced. The polymerase chain reaction (PCR) has been a natural focus of many of these miniaturization efforts, owing to its capability to efficiently replicate target regions of interest from small quantities template DNA. Scale-down of PCR has proven to be particularly challenging, however, due to an unfavorable combination of relatively severe temperature extremes (resulting in the need to repeatedly heat minute aqueous sample volumes to temperatures in the vicinity of 95°C with minimal evaporation) and high surface area to volume conditions imposed by nanoliter reactor geometries (often leading to inhibition of the reaction by nonspecific adsorption of reagents at the reactor walls). Despite these daunting challenges, considerable progress has been made in the development of microfluidic devices capable of performing increasingly sophisticated PCR-based bioassays. This chapter reviews the progress that has been made to date and assesses the outlook for future advances.
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Affiliation(s)
- Robin Hui Liu
- Osmetech Molecular Diagnostics, Pasadena, California USA
| | - Abraham P. Lee
- University of California at Irvine, Irvine, California USA
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36
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Liu C, Cui D, Cai H, Chen X, Geng Z. A rigid poly(dimethylsiloxane) sandwich electrophoresis microchip based on thin-casting method. Electrophoresis 2006; 27:2917-23. [PMID: 16721901 DOI: 10.1002/elps.200500581] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
We present a novel concept of glass/poly(dimethylsiloxane) (PDMS)/glass sandwich microchip and developed a thin-casting method for fabrication. Unlike the previously reported casting method for fabricating PDMS microchip, several drops of PDMS prepolymer were first added on the silanizing SU-8 master, then another glass plate was placed over the prepolymer as a cover plate, and formed a glass plate/PDMS prepolymer/SU-8 master sandwich mode. In order to form a thin PDMS membrane, a weight was placed on the glass plate. After the whole sandwich mode was cured at 80 degrees C for 30 min, the SU-8 master was easily peeled and the master microstructures were completely transferred to the PDMS membrane which was tightly stuck to the glass plate. The microchip was subsequently assembled by reversible sealing with the glass cover plate. We found that this PDMS sandwich microchip using the thin-casting method could withstand internal pressures of >150 kPa, more than 5 times higher than that of the PDMS hybrid microchip with reversible sealing. In addition, it shows an excellent heat-dissipating property and provides a user-friendly rigid interface just like a glass microchip, which facilitates manipulation of the microchip and fix tubing. As an application, PDMS sandwich microchips were tested in the capillary electrophoresis separation of fluorescein isothiocyanate-labeled amino acids.
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Affiliation(s)
- Changchun Liu
- State Key Laboratory of Transducer Technology, Institute of Electronics, Chinese Academy of Sciences, Beijing, P. R. China.
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37
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Davis JA, Inglis DW, Morton KJ, Lawrence DA, Huang LR, Chou SY, Sturm JC, Austin RH. Deterministic hydrodynamics: taking blood apart. Proc Natl Acad Sci U S A 2006; 103:14779-84. [PMID: 17001005 PMCID: PMC1595428 DOI: 10.1073/pnas.0605967103] [Citation(s) in RCA: 349] [Impact Index Per Article: 19.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
We show the fractionation of whole blood components and isolation of blood plasma with no dilution by using a continuous-flow deterministic array that separates blood components by their hydrodynamic size, independent of their mass. We use the technology we developed of deterministic arrays which separate white blood cells, red blood cells, and platelets from blood plasma at flow velocities of 1,000 microm/sec and volume rates up to 1 microl/min. We verified by flow cytometry that an array using focused injection removed 100% of the lymphocytes and monocytes from the main red blood cell and platelet stream. Using a second design, we demonstrated the separation of blood plasma from the blood cells (white, red, and platelets) with virtually no dilution of the plasma and no cellular contamination of the plasma.
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Affiliation(s)
- John A. Davis
- *Princeton Institute for the Science and Technology of Materials, and
- Departments of Electrical Engineering and
| | - David W. Inglis
- *Princeton Institute for the Science and Technology of Materials, and
- Departments of Electrical Engineering and
| | - Keith J. Morton
- *Princeton Institute for the Science and Technology of Materials, and
- Departments of Electrical Engineering and
| | | | - Lotien R. Huang
- *Princeton Institute for the Science and Technology of Materials, and
- Departments of Electrical Engineering and
| | - Stephen Y. Chou
- *Princeton Institute for the Science and Technology of Materials, and
- Departments of Electrical Engineering and
| | - James C. Sturm
- *Princeton Institute for the Science and Technology of Materials, and
- Departments of Electrical Engineering and
| | - Robert H. Austin
- *Princeton Institute for the Science and Technology of Materials, and
- Physics, Princeton University, Princeton, NJ 08544; and
- To whom correspondence should be addressed. E-mail:
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Pamme N, Wilhelm C. Continuous sorting of magnetic cells via on-chip free-flow magnetophoresis. LAB ON A CHIP 2006; 6:974-80. [PMID: 16874365 DOI: 10.1039/b604542a] [Citation(s) in RCA: 263] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
The ability to separate living cells is an essential aspect of cell research. Magnetic cell separation methods are among some of the most efficient methods for bulk cell separation. With the development of microfluidic platforms within the biotechnology sector, the design of miniaturised magnetic cell sorters is desirable. Here, we report the continuous sorting of cells loaded with magnetic nanoparticles in a microfluidic magnetic separation device. Cells were passed through a microfluidic chamber and were deflected from the direction of flow by means of a magnetic field. Two types of cells were studied, mouse macrophages and human ovarian cancer cells (HeLa cells). The deflection was dependent on the magnetic moment and size of the cells as well as on the applied flow rate. The experimentally observed deflection matched well with calculations. Furthermore, the separation of magnetic and non-magnetic cells was demonstrated using the same microfluidic device.
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Affiliation(s)
- Nicole Pamme
- National Institute for Materials Science (NIMS), International Centre for Young Scientists (ICYS), 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan.
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39
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Dittrich PS, Tachikawa K, Manz A. Micro Total Analysis Systems. Latest Advancements and Trends. Anal Chem 2006; 78:3887-908. [PMID: 16771530 DOI: 10.1021/ac0605602] [Citation(s) in RCA: 564] [Impact Index Per Article: 31.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Petra S Dittrich
- Institute for Analytical Sciences, Bunsen-Kirchhoff-Strasse 11, D-44139 Dortmund, Germany
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Abstract
Gentle and precise handling of cell suspensions is essential for scientific research and clinical diagnostic applications. Although different techniques for cell analysis at the micro-scale have been proposed, many still require that preliminary sample preparation steps be performed off the chip. Here we present a microstructured membrane as a new microfluidic design concept, enabling the implementation of common sample preparation procedures for suspensions of eukaryotic cells in lab-on-a-chip devices. We demonstrate the novel capabilities for sample preparation procedures by the implementation of metered sampling of nanoliter volumes of whole blood, concentration increase up to three orders of magnitude of sparse cell suspension, and circumferentially uniform, sequential exposure of cells to reagents. We implemented these functions by using microstructured membranes that are pneumatically actuated and allowed to reversibly decouple the flow of fluids and the displacement of eukaryotic cells in suspensions. Furthermore, by integrating multiple structures on the same membrane, complex sequential procedures are possible using a limited number of control steps.
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