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Kurdadze T, Lamadie F, Nehme KA, Teychené S, Biscans B, Rodriguez-Ruiz I. On-Chip Photonic Detection Techniques for Non-Invasive In Situ Characterizations at the Microfluidic Scale. SENSORS (BASEL, SWITZERLAND) 2024; 24:1529. [PMID: 38475065 DOI: 10.3390/s24051529] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2024] [Revised: 02/21/2024] [Accepted: 02/22/2024] [Indexed: 03/14/2024]
Abstract
Microfluidics has emerged as a robust technology for diverse applications, ranging from bio-medical diagnostics to chemical analysis. Among the different characterization techniques that can be used to analyze samples at the microfluidic scale, the coupling of photonic detection techniques and on-chip configurations is particularly advantageous due to its non-invasive nature, which permits sensitive, real-time, high throughput, and rapid analyses, taking advantage of the microfluidic special environments and reduced sample volumes. Putting a special emphasis on integrated detection schemes, this review article explores the most relevant advances in the on-chip implementation of UV-vis, near-infrared, terahertz, and X-ray-based techniques for different characterizations, ranging from punctual spectroscopic or scattering-based measurements to different types of mapping/imaging. The principles of the techniques and their interest are discussed through their application to different systems.
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Affiliation(s)
- Tamar Kurdadze
- CEA, DES, ISEC, DMRC, Univ Montpellier, 30207 Bagnols-sur-Ceze, Marcoule, France
| | - Fabrice Lamadie
- CEA, DES, ISEC, DMRC, Univ Montpellier, 30207 Bagnols-sur-Ceze, Marcoule, France
| | - Karen A Nehme
- Laboratoire de Génie Chimique, CNRS, UMR 5503, 4 Allée Emile Monso, 31432 Toulouse, France
| | - Sébastien Teychené
- Laboratoire de Génie Chimique, CNRS, UMR 5503, 4 Allée Emile Monso, 31432 Toulouse, France
| | - Béatrice Biscans
- Laboratoire de Génie Chimique, CNRS, UMR 5503, 4 Allée Emile Monso, 31432 Toulouse, France
| | - Isaac Rodriguez-Ruiz
- Laboratoire de Génie Chimique, CNRS, UMR 5503, 4 Allée Emile Monso, 31432 Toulouse, France
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2
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Akimoto T, Yasuda K. Content Size-Dependent Alginate Microcapsule Formation Using Centrifugation to Eliminate Empty Microcapsules for On-Chip Imaging Cell Sorter Application. MICROMACHINES 2022; 14:72. [PMID: 36677133 PMCID: PMC9867324 DOI: 10.3390/mi14010072] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Revised: 12/23/2022] [Accepted: 12/23/2022] [Indexed: 06/17/2023]
Abstract
Alginate microcapsules are one of the attractive non-invasive platforms for handling individual cells and clusters, maintaining their isolation for further applications such as imaging cell sorter and single capsule qPCR. However, the conventional cell encapsulation techniques provide huge numbers of unnecessary empty homogeneous alginate microcapsules, which spend an excessive majority of the machine time on observations and analysis. Here, we developed a simple alginate cell encapsulation method to form content size-dependent alginate microcapsules to eliminate empty microcapsules using microcapillary centrifugation and filtration. Using this method, the formed calcium alginate microcapsules containing the HeLa cells were larger than 20m, and the other empty microcapsules were less than 3m under 4000 rpm centrifugation condition. We collected cell-containing alginate microcapsules by eliminating empty microcapsules from the microcapsule mixture with simple one-step filtration of a 20 m cell strainer. The electrical surface charge density and optical permeability of those cell-encapsulated alginate microcapsules were also evaluated. We found that the surface charge density of cell-encapsulated alginate microbeads is more than double that of cells, indicating that less voltage is required for electrical cell handling with thin alginate gel encapsulation of samples. The permeability of the alginate microcapsule was not improved by changing the reflective index of the medium buffer, such as adding alginate ester. However, the minimized thickness of the alginate gel envelope surrounding cells in the microcapsules did not degrade the detailed shapes of encapsulated cells. Those results confirmed the advantage of alginate encapsulation of cells with the centrifugation method as one of the desirable tools for imaging cell sorting applications.
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Affiliation(s)
- Toshinosuke Akimoto
- Department of Pure and Applied Physics, Graduate School of Advanced Science and Engineering, Waseda University, 3-4-1 Okubo, Shinjuku, Tokyo 169-8555, Japan
| | - Kenji Yasuda
- Department of Pure and Applied Physics, Graduate School of Advanced Science and Engineering, Waseda University, 3-4-1 Okubo, Shinjuku, Tokyo 169-8555, Japan
- Department of Physics, School of Advanced Science and Engineering, Waseda University, 3-4-1 Okubo, Shinjuku, Tokyo 169-8555, Japan
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3
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Li Z, Yi G, Cai Z, Gao Z. Impingement and mixing between two shear-thinning droplets on the solid surface. Chem Eng Sci 2022. [DOI: 10.1016/j.ces.2022.118293] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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4
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Marcali M, Chen X, Aucoin MG, Ren CL. Droplet formation of biological non-Newtonian fluid in T-junction generators. I. Experimental investigation. Phys Rev E 2022; 105:025105. [PMID: 35291127 DOI: 10.1103/physreve.105.025105] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2021] [Accepted: 12/29/2021] [Indexed: 06/14/2023]
Abstract
The extension of microfluidics to many bioassay applications requires the ability to work with non-Newtonian fluids. One case in point is the use of microfluidics with blood having different hematocrit levels. This work is the first part of a two-part study and presents the formation dynamics of blood droplets in a T-junction generator under the squeezing regime. In this regime, droplet formation with Newtonian fluids depends on T-junction geometry; however, we found that in the presence of the non-Newtonian fluid such as red blood cells, the formation depends on not only to the channel geometry, but also the flow rate ratio of fluids, and the viscosity of the phases. In addition, we analyzed the impact of the red blood cell concentration on the formation cycle. In this study, we presented the experimental data of the blood droplet evolution through the analysis of videos that are captured by a high-speed camera. During this analysis, we tracked several parameters such as droplet volume, spacing between droplets, droplet generation frequency, flow conditions, and geometrical designs of the T junction. Our analysis revealed that, unlike other non-Newtonian fluids, where the fourth stage exists (stretching stage), the formation cycle consists of only three stages: lag, filling, and necking stages. Because of the detailed analysis of each stage, a mathematical model can be generated to predict the final volume of the blood droplet and can be utilized as a guide in the operation of the microfluidic device for biochemical assay applications; this is the focus of the second part of this study [Phys. Rev. E 105, 025106 (2022)10.1103/PhysRevE.105.025106].
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Affiliation(s)
- Merve Marcali
- Department of Mechanical and Mechatronics Engineering, University of Waterloo, Waterloo, Ontario, Canada
| | - Xiaoming Chen
- Department of Mechanical and Mechatronics Engineering, University of Waterloo, Waterloo, Ontario, Canada
| | - Marc G Aucoin
- Department of Chemical Engineering, University of Waterloo, Waterloo, Ontario, Canada
| | - Carolyn L Ren
- Department of Mechanical and Mechatronics Engineering, University of Waterloo, Waterloo, Ontario, Canada
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5
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Deng Y, Guo W, Zhu C, Fu T, Ma Y. Coalescence dynamics of two droplets in T-junction microchannel with a lantern-shaped expansion chamber. J Taiwan Inst Chem Eng 2022. [DOI: 10.1016/j.jtice.2021.104193] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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6
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A Monolithic 3D Printed Axisymmetric Co-Flow Single and Compound Emulsion Generator. MICROMACHINES 2022; 13:mi13020188. [PMID: 35208313 PMCID: PMC8877394 DOI: 10.3390/mi13020188] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/31/2021] [Revised: 01/12/2022] [Accepted: 01/12/2022] [Indexed: 11/24/2022]
Abstract
We report a microfluidic droplet generator which can produce single and compound droplets using a 3D axisymmetric co-flow structure. The design considered for the fabrication of the device integrated a user-friendly and cost-effective 3D printing process. To verify the performance of the device, single and compound emulsions of deionized water and mineral oil were generated and their features such as size, generation frequency, and emulsion structures were successfully characterized. In addition, the generation of bio emulsions such as alginate and collagen aqueous droplets in mineral oil was demonstrated in this study. Overall, the monolithic 3D printed axisymmetric droplet generator could offer any user an accessible and easy-to-utilize device for the generation of single and compound emulsions.
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Manipulation and control of droplets on surfaces in a homogeneous electric field. Nat Commun 2022; 13:289. [PMID: 35022399 PMCID: PMC8755840 DOI: 10.1038/s41467-021-27879-0] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2021] [Accepted: 12/07/2021] [Indexed: 01/17/2023] Open
Abstract
A method to manipulate and control droplets on a surface is presented. The method is based on inducing electric dipoles inside the droplets using a homogeneous external electric field. It is shown that the repulsive dipole force efficiently suppresses the coalescence of droplets moving on a liquid-infused surface (LIS). Using a combination of experiments, numerical computations and semi-analytical models, the dependence of the repulsion force on the droplet volumes, the distance between the droplets and the electric field strength is revealed. The method allows to suppress coalescence in complex multi-droplet flows and is real-time adaptive. When the electric field strength exceeds a critical value, tip streaming from the droplets sets in. Based on that, it becomes possible to withdraw minute samples from an array of droplets in a parallel process. Control of droplet coalescence is a major challenge of droplet microfluidics. Here, the authors show that homogenous external electric field can induce dipoles inside droplets, which can be used to withdraw samples from an array of droplets.
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Lu D, Jin Y, Wang X, Xie L, Liu Q, Chen Y, Wang H, Lei Z. Heparin-like anticoagulant polypeptides with tunable activity: Synthesis, characterization, anticoagulative properties and clot solubilities in vitro. MATERIALS SCIENCE & ENGINEERING. C, MATERIALS FOR BIOLOGICAL APPLICATIONS 2021; 129:112405. [PMID: 34579917 DOI: 10.1016/j.msec.2021.112405] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2021] [Revised: 08/05/2021] [Accepted: 08/26/2021] [Indexed: 12/28/2022]
Abstract
Due to the uncontrollable anticoagulant activity and limited source, Heparin, which is commonly used in clinical anticoagulation therapies, faces the risk of spontaneous bleeding and thrombocytopenia. Herein, a series of anionic poly(amino acid) s poly (l-Serine-ran-L-Glutamic acid-ran-L-Cysteine-SO3) (PSEC-SO3) were prepared by the controlled Ring Opening Polymerization (ROP) of N-Carboxyanhydrides (NCAs). The anticoagulant activities of PSEC-SO3 can be regulated by simply adjusting the feeding ratio of monomers. In vitro tests show that these polypeptides can effectively prolong the Activated Partical Thromboplastin Time (APTT) and inhibit Factor IIa and Factor Xa, but has no significant effect on Prothrombin Time (PT) and Thrombin Time (TT), which indicates that PSEC-SO3 mainly act on the intrinsic pathway. In summary, the activity-tunable heparin-like polypeptides are expected to have good application prospects in the anticoagulant field.
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Affiliation(s)
- Dedai Lu
- Key Laboratory of Eco-functional Polymer Materials of the Ministry of Education, Key Laboratory of Eco-environmental Polymer Materials of Gansu Province, College of Chemistry and Chemical Engineering, Northwest Normal University, Lanzhou 730070, China.
| | - Yuanyuan Jin
- Key Laboratory of Eco-functional Polymer Materials of the Ministry of Education, Key Laboratory of Eco-environmental Polymer Materials of Gansu Province, College of Chemistry and Chemical Engineering, Northwest Normal University, Lanzhou 730070, China
| | - Xiangya Wang
- Key Laboratory of Eco-functional Polymer Materials of the Ministry of Education, Key Laboratory of Eco-environmental Polymer Materials of Gansu Province, College of Chemistry and Chemical Engineering, Northwest Normal University, Lanzhou 730070, China
| | - Liyuan Xie
- Key Laboratory of Eco-functional Polymer Materials of the Ministry of Education, Key Laboratory of Eco-environmental Polymer Materials of Gansu Province, College of Chemistry and Chemical Engineering, Northwest Normal University, Lanzhou 730070, China
| | - Qianqian Liu
- Key Laboratory of Eco-functional Polymer Materials of the Ministry of Education, Key Laboratory of Eco-environmental Polymer Materials of Gansu Province, College of Chemistry and Chemical Engineering, Northwest Normal University, Lanzhou 730070, China
| | - Yamin Chen
- Key Laboratory of Eco-functional Polymer Materials of the Ministry of Education, Key Laboratory of Eco-environmental Polymer Materials of Gansu Province, College of Chemistry and Chemical Engineering, Northwest Normal University, Lanzhou 730070, China
| | - Hui Wang
- Key Laboratory of Eco-functional Polymer Materials of the Ministry of Education, Key Laboratory of Eco-environmental Polymer Materials of Gansu Province, College of Chemistry and Chemical Engineering, Northwest Normal University, Lanzhou 730070, China
| | - Ziqiang Lei
- Key Laboratory of Eco-functional Polymer Materials of the Ministry of Education, Key Laboratory of Eco-environmental Polymer Materials of Gansu Province, College of Chemistry and Chemical Engineering, Northwest Normal University, Lanzhou 730070, China
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Diamond SL, Rossi JM. Point of care whole blood microfluidics for detecting and managing thrombotic and bleeding risks. LAB ON A CHIP 2021; 21:3667-3674. [PMID: 34476426 PMCID: PMC8478847 DOI: 10.1039/d1lc00465d] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Point-of-care diagnostics of platelet and coagulation function present demanding challenges. Current clinical diagnostics often use centrifuged plasmas or platelets and frozen plasma standards, recombinant protein standards, or even venoms. Almost all commercialized tests of blood do not recreate the in vivo hemodynamics where platelets accumulate to high densities and thrombin is generated from a procoagulant surface. Despite numerous drugs that target platelets, insufficient coagulation, or excess coagulation, POC blood testing is essentially limited to viscoelastic methods that provide a clotting time, clot strength, and clot lysis, while used mostly in trauma centers with specialized capabilities. Microfluidics now allows small volumes of whole blood (<1 mL) to be tested under venous or arterial shear rates with multi-color readouts to follow platelet function, thrombin generation, fibrin production, and clot stability. Injection molded chips containing pre-patterned fibrillar collagen and lipidated tissue factor can be stored dry for 6 months at 4C, thus allowing rapid blood testing on single-use disposable chips. Using only a small imaging microscope and micropump, these microfluidic devices can detect platelet inhibitors, direct oral anticoagulants (DOACs) and their reversal agents. POC microfluidics are ideal for neonatal surgical applications that involve small blood samples, rapid DOAC testing in stroke or bleeding or emergency surgery situations with patients presenting high risk cofactors for either bleeding or thrombosis.
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Affiliation(s)
- Scott L Diamond
- Institute for Medicine and Engineering, Department of Chemical and Biomolecular Engineering, University of Pennsylvania, 1024 Vagelos Research Laboratory, Philadelphia, PA 19104, USA.
| | - Jason M Rossi
- Institute for Medicine and Engineering, Department of Chemical and Biomolecular Engineering, University of Pennsylvania, 1024 Vagelos Research Laboratory, Philadelphia, PA 19104, USA.
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10
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Morikawa K, Ohta R, Mawatari K, Kitamori T. Metal-Free Fabrication of Fused Silica Extended Nanofluidic Channel to Remove Artifacts in Chemical Analysis. MICROMACHINES 2021; 12:mi12080917. [PMID: 34442539 PMCID: PMC8399996 DOI: 10.3390/mi12080917] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Revised: 07/29/2021] [Accepted: 07/30/2021] [Indexed: 11/16/2022]
Abstract
In microfluidics, especially in nanofluidics, nanochannels with functionalized surfaces have recently attracted attention for use as a new tool for the investigation of chemical reaction fields. Molecules handled in the reaction field can reach the single-molecule level due to the small size of the nanochannel. In such surroundings, contamination of the channel surface should be removed at the single-molecule level. In this study, it was assumed that metal materials could contaminate the nanochannels during the fabrication processes; therefore, we aimed to develop metal-free fabrication processes. Fused silica channels 1000 nm-deep were conventionally fabricated using a chromium mask. Instead of chromium, electron beam resists more than 1000 nm thick were used and the lithography conditions were optimized. From the results of optimization, channels with 1000 nm scale width and depth were fabricated on fused silica substrates without the use of a chromium mask. In nanofluidic experiments, an oxidation reaction was observed in a device fabricated by conventional fabrication processes using a chromium mask. It was found that Cr6+ remained on the channel surfaces and reacted with chemicals in the liquid phase in the extended nanochannels; this effect occurred at least to the micromolar level. In contrast, the device fabricated with metal-free processes was free of artifacts induced by the presence of chromium. The developed fabrication processes and results of this study will be a significant contribution to the fundamental technologies employed in the fields of microfluidics and nanofluidics.
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Affiliation(s)
- Kyojiro Morikawa
- Collaborative Research Organization for Micro and Nano Multifunctional Devices (NMfD), The University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo 113-8656, Japan
| | - Ryoichi Ohta
- Collaborative Research Organization for Micro and Nano Multifunctional Devices (NMfD), The University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo 113-8656, Japan
| | - Kazuma Mawatari
- Department of Applied Chemistry, School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo 113-8656, Japan
| | - Takehiko Kitamori
- Collaborative Research Organization for Micro and Nano Multifunctional Devices (NMfD), The University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo 113-8656, Japan
- Institute of Nanoengineering and Microsystems (iNEMS), Department of Power Mechanical Engineering, National Tsing Hua University, No. 101, Section 2, Kuang-Fu Road, Hsinchu 30013, Taiwan
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Sui J, Yan J, Liu D, Wang K, Luo G. Continuous Synthesis of Nanocrystals via Flow Chemistry Technology. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2020; 16:e1902828. [PMID: 31755221 DOI: 10.1002/smll.201902828] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Revised: 10/11/2019] [Indexed: 05/28/2023]
Abstract
Modern nanotechnologies bring humanity to a new age, and advanced methods for preparing functional nanocrystals are cornerstones. A considerable variety of nanomaterials has been created over the past decades, but few were prepared on the macro scale, even fewer making it to the stage of industrial production. The gap between academic research and engineering production is expected to be filled by flow chemistry technology, which relies on microreactors. Microreaction devices and technologies for synthesizing different kinds of nanocrystals are discussed from an engineering point of view. The advantages of microreactors, the important features of flow chemistry systems, and methods to apply them in the syntheses of salt, oxide, metal, alloy, and quantum dot nanomaterials are summarized. To further exhibit the scaling-up of nanocrystal synthesis, recent reports on using microreactors with gram per hour and larger production rates are highlighted. Finally, an industrial example for preparing 10 tons of CaCO3 nanoparticles per day is introduced, which shows the great potential for flow chemistry processes to transfer lab research to industry.
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Affiliation(s)
- Jinsong Sui
- The State Key Lab of Chemical Engineering, Department of Chemical Engineering, Tsinghua University, Beijing, 100084, China
| | - Junyu Yan
- The State Key Lab of Chemical Engineering, Department of Chemical Engineering, Tsinghua University, Beijing, 100084, China
| | - Di Liu
- The State Key Lab of Chemical Engineering, Department of Chemical Engineering, Tsinghua University, Beijing, 100084, China
| | - Kai Wang
- The State Key Lab of Chemical Engineering, Department of Chemical Engineering, Tsinghua University, Beijing, 100084, China
| | - Guangsheng Luo
- The State Key Lab of Chemical Engineering, Department of Chemical Engineering, Tsinghua University, Beijing, 100084, China
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12
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Jigar Panchal H, Kent NJ, Knox AJS, Harris LF. Microfluidics in Haemostasis: A Review. Molecules 2020; 25:E833. [PMID: 32075008 PMCID: PMC7070452 DOI: 10.3390/molecules25040833] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2020] [Revised: 02/11/2020] [Accepted: 02/12/2020] [Indexed: 12/17/2022] Open
Abstract
Haemostatic disorders are both complex and costly in relation to both their treatment and subsequent management. As leading causes of mortality worldwide, there is an ever-increasing drive to improve the diagnosis and prevention of haemostatic disorders. The field of microfluidic and Lab on a Chip (LOC) technologies is rapidly advancing and the important role of miniaturised diagnostics is becoming more evident in the healthcare system, with particular importance in near patient testing (NPT) and point of care (POC) settings. Microfluidic technologies present innovative solutions to diagnostic and clinical challenges which have the knock-on effect of improving health care and quality of life. In this review, both advanced microfluidic devices (R&D) and commercially available devices for the diagnosis and monitoring of haemostasis-related disorders and antithrombotic therapies, respectively, are discussed. Innovative design specifications, fabrication techniques, and modes of detection in addition to the materials used in developing micro-channels are reviewed in the context of application to the field of haemostasis.
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Affiliation(s)
- Heta Jigar Panchal
- School of Biological and Health Sciences, Technological University Dublin (TU Dublin) - City Campus, Kevin Street, Dublin D08 NF82, Ireland; (H.J.P.); (A.J.S.K.)
| | - Nigel J Kent
- engCORE, Faculty of Engineering, Institute of Technology Carlow, Kilkenny Road, Carlow R93 V960, Ireland;
| | - Andrew J S Knox
- School of Biological and Health Sciences, Technological University Dublin (TU Dublin) - City Campus, Kevin Street, Dublin D08 NF82, Ireland; (H.J.P.); (A.J.S.K.)
| | - Leanne F Harris
- School of Biological and Health Sciences, Technological University Dublin (TU Dublin) - City Campus, Kevin Street, Dublin D08 NF82, Ireland; (H.J.P.); (A.J.S.K.)
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13
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Ma P, Liang D, Zhu C, Fu T, Ma Y. An effective method to facile coalescence of microdroplet in the symmetrical T-junction with expanded convergence. Chem Eng Sci 2020. [DOI: 10.1016/j.ces.2019.115389] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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14
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Droplet Microfluidics-Enabled High-Throughput Screening for Protein Engineering. MICROMACHINES 2019; 10:mi10110734. [PMID: 31671786 PMCID: PMC6915371 DOI: 10.3390/mi10110734] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/05/2019] [Revised: 10/22/2019] [Accepted: 10/26/2019] [Indexed: 12/19/2022]
Abstract
Protein engineering—the process of developing useful or valuable proteins—has successfully created a wide range of proteins tailored to specific agricultural, industrial, and biomedical applications. Protein engineering may rely on rational techniques informed by structural models, phylogenic information, or computational methods or it may rely upon random techniques such as chemical mutation, DNA shuffling, error prone polymerase chain reaction (PCR), etc. The increasing capabilities of rational protein design coupled to the rapid production of large variant libraries have seriously challenged the capacity of traditional screening and selection techniques. Similarly, random approaches based on directed evolution, which relies on the Darwinian principles of mutation and selection to steer proteins toward desired traits, also requires the screening of very large libraries of mutants to be truly effective. For either rational or random approaches, the highest possible screening throughput facilitates efficient protein engineering strategies. In the last decade, high-throughput screening (HTS) for protein engineering has been leveraging the emerging technologies of droplet microfluidics. Droplet microfluidics, featuring controlled formation and manipulation of nano- to femtoliter droplets of one fluid phase in another, has presented a new paradigm for screening, providing increased throughput, reduced reagent volume, and scalability. We review here the recent droplet microfluidics-based HTS systems developed for protein engineering, particularly directed evolution. The current review can also serve as a tutorial guide for protein engineers and molecular biologists who need a droplet microfluidics-based HTS system for their specific applications but may not have prior knowledge about microfluidics. In the end, several challenges and opportunities are identified to motivate the continued innovation of microfluidics with implications for protein engineering.
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15
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Feng S, Shirani E, Inglis DW. Droplets for Sampling and Transport of Chemical Signals in Biosensing: A Review. BIOSENSORS 2019; 9:E80. [PMID: 31226857 PMCID: PMC6627903 DOI: 10.3390/bios9020080] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/02/2019] [Revised: 06/14/2019] [Accepted: 06/17/2019] [Indexed: 12/14/2022]
Abstract
The chemical, temporal, and spatial resolution of chemical signals that are sampled and transported with continuous flow is limited because of Taylor dispersion. Droplets have been used to solve this problem by digitizing chemical signals into discrete segments that can be transported for a long distance or a long time without loss of chemical, temporal or spatial precision. In this review, we describe Taylor dispersion, sampling theory, and Laplace pressure, and give examples of sampling probes that have used droplets to sample or/and transport fluid from a continuous medium, such as cell culture or nerve tissue, for external analysis. The examples are categorized, as follows: (1) Aqueous-phase sampling with downstream droplet formation; (2) preformed droplets for sampling; and (3) droplets formed near the analyte source. Finally, strategies for downstream sample recovery for conventional analysis are described.
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Affiliation(s)
- Shilun Feng
- School of Engineering, Macquarie University, Sydney, NSW 2109, Australia.
- ARC Centre of Excellence for Nanoscale BioPhotonics (CNBP), Macquarie University, Sydney, NSW 2109, Australia.
| | - Elham Shirani
- School of Engineering, Macquarie University, Sydney, NSW 2109, Australia.
| | - David W Inglis
- School of Engineering, Macquarie University, Sydney, NSW 2109, Australia.
- ARC Centre of Excellence for Nanoscale BioPhotonics (CNBP), Macquarie University, Sydney, NSW 2109, Australia.
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16
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Wang X, Sun M, Ferguson SA, Hoff JD, Qin Y, Bailey RC, Meyerhoff ME. Ionophore‐Based Biphasic Chemical Sensing in Droplet Microfluidics. Angew Chem Int Ed Engl 2019. [DOI: 10.1002/ange.201902960] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Xuewei Wang
- Department of Chemistry University of Michigan 930 N University Ann Arbor MI 48109 USA
| | - Meng Sun
- Department of Chemistry University of Michigan 930 N University Ann Arbor MI 48109 USA
- Department of Biophysics University of Michigan 930 N University Ann Arbor MI 48109 USA
| | - Stephen A. Ferguson
- Department of Chemistry University of Michigan 930 N University Ann Arbor MI 48109 USA
| | - J. Damon Hoff
- Department of Biophysics University of Michigan 930 N University Ann Arbor MI 48109 USA
| | - Yu Qin
- Department of Chemistry University of Michigan 930 N University Ann Arbor MI 48109 USA
| | - Ryan C. Bailey
- Department of Chemistry University of Michigan 930 N University Ann Arbor MI 48109 USA
| | - Mark E. Meyerhoff
- Department of Chemistry University of Michigan 930 N University Ann Arbor MI 48109 USA
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17
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Ionophore‐Based Biphasic Chemical Sensing in Droplet Microfluidics. Angew Chem Int Ed Engl 2019; 58:8092-8096. [DOI: 10.1002/anie.201902960] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2019] [Revised: 04/14/2019] [Indexed: 01/24/2023]
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18
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Fu Y, Wang H, Zhang X, Bai L, Jin Y, Cheng Y. Numerical simulation of liquid mixing inside soft droplets with periodic deformation by a lattice Boltzmann method. J Taiwan Inst Chem Eng 2019. [DOI: 10.1016/j.jtice.2018.08.025] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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19
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Du L, Li Y, Gao R, Yin J, Shen C, Wang Y, Luo G. Controllability and flexibility in particle manufacturing of a segmented microfluidic device with passive picoinjection. AIChE J 2018. [DOI: 10.1002/aic.16356] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Affiliation(s)
- Le Du
- The State Key Laboratory of Chemical Resource Engineering, Beijing Key Laboratory of Membrane Science and Technology; Beijing University of Chemical Technology; Beijing 100029 China
| | - Yang Li
- The State Key Laboratory of Chemical Resource Engineering, Beijing Key Laboratory of Membrane Science and Technology; Beijing University of Chemical Technology; Beijing 100029 China
| | - Ruomei Gao
- The State Key Lab of Chemical Engineering, Dept. of Chemical Engineering; Tsinghua University; Beijing 100084 China
| | - Jiabin Yin
- Beijing Key Laboratory of Bioprocess, College of Life Science and Technology; Beijing University of Chemical Technology; Beijing 100029 China
| | - Chun Shen
- Beijing Key Laboratory of Bioprocess, College of Life Science and Technology; Beijing University of Chemical Technology; Beijing 100029 China
| | - Yujun Wang
- The State Key Lab of Chemical Engineering, Dept. of Chemical Engineering; Tsinghua University; Beijing 100084 China
| | - Guangsheng Luo
- The State Key Lab of Chemical Engineering, Dept. of Chemical Engineering; Tsinghua University; Beijing 100084 China
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20
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Pan LJ, Tu JW, Ma HT, Yang YJ, Tian ZQ, Pang DW, Zhang ZL. Controllable synthesis of nanocrystals in droplet reactors. LAB ON A CHIP 2017; 18:41-56. [PMID: 29098217 DOI: 10.1039/c7lc00800g] [Citation(s) in RCA: 67] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
In recent years, a broad range of nanocrystals have been synthesized in droplet-based microfluidic reactors which provide obvious advantages, such as accurate manipulation, better reproducibility and reliable automation. In this review, we initially introduce general concepts of droplet reactors followed by discussions of their main functional regions including droplet generation, mixing of reactants, reaction controlling, in situ monitoring, and reaction quenching. Subsequently, the enhanced mass and heat transport properties are discussed. Next, we focus on research frontiers including sequential multistep synthesis, intelligent synthesis, reliable scale-up synthesis, and interfacial synthesis. Finally, we end with an outlook on droplet reactors, especially highlighting some aspects such as large-scale production, the integrated process of synthesis and post-synthetic treatments, automated droplet reactors with in situ monitoring and optimizing algorithms, and rapidly developing strategies for interfacial synthesis.
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Affiliation(s)
- Liang-Jun Pan
- Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education), College of Chemistry and Molecular Science, Wuhan University, Wuhan 430072, People's Republic of China.
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21
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Zhang C, Neelamegham S. Application of microfluidic devices in studies of thrombosis and hemostasis. Platelets 2017; 28:434-440. [PMID: 28580870 DOI: 10.1080/09537104.2017.1319047] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Due to the importance of fluid flow during thrombotic episodes, it is quite appropriate to study clotting and bleeding processes in devices that have well-defined fluid shear environments. Two common devices for applying these defined shear stresses include the cone-and-plate viscometer and parallel-plate flow chamber. While such tools have many salient features, they require large amounts of blood or other protein components. With growth in the area of microfluidics over the last two decades, it has become feasible to miniaturize such flow devices. Such miniaturization not only enables saving of precious samples but also increases the throughput of fluid shear devices, thus enabling the design of combinatorial experiments and making the technique more accessible to the larger scientific community. In addition to simple flows that are common in traditional flow apparatus, more complex geometries that mimic stenosed arteries and the human microvasculature can also be generated. The composition of the microfluidics cell substrate can also be varied for diverse basic science investigations, and clinical investigations that aim to assay either individual patient coagulopathy or response to anti-coagulation treatment. This review summarizes the current state of the art for such microfluidic devices and their applications in the field of thrombosis and hemostasis.
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Affiliation(s)
- Changjie Zhang
- a Chemical and Biological Engineering, and Clinical & Translational Research Center , University at Buffalo, State University of New York , Buffalo , NY , USA
| | - Sriram Neelamegham
- a Chemical and Biological Engineering, and Clinical & Translational Research Center , University at Buffalo, State University of New York , Buffalo , NY , USA
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22
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Wu F, Xu T, Zhao G, Meng S, Wan M, Chi B, Mao C, Shen J. Mesoporous Silica Nanoparticles-Encapsulated Agarose and Heparin as Anticoagulant and Resisting Bacterial Adhesion Coating for Biomedical Silicone. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2017; 33:5245-5252. [PMID: 28498661 DOI: 10.1021/acs.langmuir.7b00567] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Silicone catheter has been widely used in peritoneal dialysis. The research missions of improving blood compatibility and the ability of resisting bacterial adhesion of silicone catheter have been implemented for the biomedical requirements. However, most of modification methods of surface modification were only able to develop the blood-contacting biomaterials with good hemocompatibility. It is difficult for the biomaterials to resist bacterial adhesion. Here, agarose was selected to resist bacterial adhesion, and heparin was chosen to improve hemocompatibility of materials. Both of them were loaded into mesoporous silica nanoparticles (MSNs), which were successfully modified on the silicone film surface via electrostatic interaction. Structures of the mesoporous coatings were characterized in detail by dynamic light scattering, transmission electron microscopy, Brunauer-Emmett-Teller surface area, thermogravimetric analysis, Fourier transform infrared spectroscopy, scanning electron microscope, and water contact angle. Platelet adhesion and aggregation, whole blood contact test, hemolysis and related morphology test of red blood cells, in vitro clotting time tests, and bacterial adhesion assay were performed to evaluate the anticoagulant effect and the ability of resisting bacterial adhesion of the modified silicone films. Results indicated that silicone films modified by MSNs had a good anticoagulant effect and could resist bacterial adhesion. The modified silicone films have potential as blood-contacting biomaterials that were attributed to their biomedical properties.
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Affiliation(s)
- Fan Wu
- National and Local Joint Engineering Research Center of Biomedical Functional Materials, Jiangsu Key Laboratory of Biofunctional Materials, School of Chemistry and Materials Science, Nanjing Normal University , Nanjing 210023, China
| | - Tingting Xu
- National and Local Joint Engineering Research Center of Biomedical Functional Materials, Jiangsu Key Laboratory of Biofunctional Materials, School of Chemistry and Materials Science, Nanjing Normal University , Nanjing 210023, China
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Food Science and Light Industry, Nanjing Tech University , Nanjing 211816, China
| | - Guangyao Zhao
- National and Local Joint Engineering Research Center of Biomedical Functional Materials, Jiangsu Key Laboratory of Biofunctional Materials, School of Chemistry and Materials Science, Nanjing Normal University , Nanjing 210023, China
| | - Shuangshuang Meng
- National and Local Joint Engineering Research Center of Biomedical Functional Materials, Jiangsu Key Laboratory of Biofunctional Materials, School of Chemistry and Materials Science, Nanjing Normal University , Nanjing 210023, China
| | - Mimi Wan
- National and Local Joint Engineering Research Center of Biomedical Functional Materials, Jiangsu Key Laboratory of Biofunctional Materials, School of Chemistry and Materials Science, Nanjing Normal University , Nanjing 210023, China
| | - Bo Chi
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Food Science and Light Industry, Nanjing Tech University , Nanjing 211816, China
| | - Chun Mao
- National and Local Joint Engineering Research Center of Biomedical Functional Materials, Jiangsu Key Laboratory of Biofunctional Materials, School of Chemistry and Materials Science, Nanjing Normal University , Nanjing 210023, China
| | - Jian Shen
- National and Local Joint Engineering Research Center of Biomedical Functional Materials, Jiangsu Key Laboratory of Biofunctional Materials, School of Chemistry and Materials Science, Nanjing Normal University , Nanjing 210023, China
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23
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Abstract
Droplet microfluidics generates and manipulates discrete droplets through immiscible multiphase flows inside microchannels. Due to its remarkable advantages, droplet microfluidics bears significant value in an extremely wide range of area. In this review, we provide a comprehensive and in-depth insight into droplet microfluidics, covering fundamental research from microfluidic chip fabrication and droplet generation to the applications of droplets in bio(chemical) analysis and materials generation. The purpose of this review is to convey the fundamentals of droplet microfluidics, a critical analysis on its current status and challenges, and opinions on its future development. We believe this review will promote communications among biology, chemistry, physics, and materials science.
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Affiliation(s)
- Luoran Shang
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University , Nanjing 210096, China
| | - Yao Cheng
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University , Nanjing 210096, China
| | - Yuanjin Zhao
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University , Nanjing 210096, China
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24
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Ouimet CM, D’Amico CI, Kennedy RT. Advances in capillary electrophoresis and the implications for drug discovery. Expert Opin Drug Discov 2017; 12:213-224. [PMID: 27911223 PMCID: PMC5521262 DOI: 10.1080/17460441.2017.1268121] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
INTRODUCTION Many screening platforms are prone to assay interferences that can be avoided by directly measuring the target or enzymatic product. Capillary electrophoresis (CE) and microchip electrophoresis (MCE) have been applied in a variety of formats to drug discovery. CE provides direct detection of the product allowing for the identification of some forms of assay interference. The high efficiency, rapid separations, and low volume requirements make CE amenable to drug discovery. Areas covered: This article describes advances in capillary electrophoresis throughput, sample introduction, and target assays as they pertain to drug discovery and screening. Instrumental advances discussed include integrated droplet microfluidics platforms and multiplexed arrays. Applications of CE to assays of diverse drug discovery targets, including enzymes and affinity interactions are also described. Expert opinion: Current screening with CE does not fully take advantage of the throughputs or low sample volumes possible with CE and is most suitable as a secondary screening method or for screens that are inaccessible with more common platforms. With further development, droplet microfluidics coupled to MCE could take advantage of the low sample requirements by performing assays on the nanoliter scale at high throughput.
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Affiliation(s)
- Claire M. Ouimet
- Department of Chemistry, University of Michigan, 930 N. University Ave, Ann Arbor, MI, 48109, United States
| | - Cara I. D’Amico
- Department of Pharmacology, University of Michigan, 1150 W. Medical Center Dr., Ann Arbor, MI, 48109, United States
| | - Robert T. Kennedy
- Department of Chemistry, University of Michigan, 930 N. University Ave, Ann Arbor, MI, 48109, United States
- Department of Pharmacology, University of Michigan, 1150 W. Medical Center Dr., Ann Arbor, MI, 48109, United States
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25
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Wang X, Liu Z, Pang Y. Concentration gradient generation methods based on microfluidic systems. RSC Adv 2017. [DOI: 10.1039/c7ra04494a] [Citation(s) in RCA: 113] [Impact Index Per Article: 16.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Various concentration gradient generation methods based on microfluidic systems are summarized in this paper.
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Affiliation(s)
- Xiang Wang
- College of Mechanical Engineering and Applied Electronics Technology
- Beijing University of Technology
- Beijing 100124
- China
| | - Zhaomiao Liu
- College of Mechanical Engineering and Applied Electronics Technology
- Beijing University of Technology
- Beijing 100124
- China
| | - Yan Pang
- College of Mechanical Engineering and Applied Electronics Technology
- Beijing University of Technology
- Beijing 100124
- China
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26
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Abstract
Engineering characteristics of liquid–liquid microflow and its advantages in chemical reactions.
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Affiliation(s)
- Kai Wang
- The State Key Laboratory of Chemical Engineering
- Department of Chemical Engineering
- Tsinghua University
- Beijing 100084
- China
| | - Liantang Li
- The State Key Laboratory of Chemical Engineering
- Department of Chemical Engineering
- Tsinghua University
- Beijing 100084
- China
| | - Pei Xie
- The State Key Laboratory of Chemical Engineering
- Department of Chemical Engineering
- Tsinghua University
- Beijing 100084
- China
| | - Guangsheng Luo
- The State Key Laboratory of Chemical Engineering
- Department of Chemical Engineering
- Tsinghua University
- Beijing 100084
- China
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27
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Fu Y, Bai L, Zhao S, Bi K, Jin Y, Cheng Y. Droplet in droplet: LBM simulation of modulated liquid mixing. Chem Eng Sci 2016. [DOI: 10.1016/j.ces.2016.08.035] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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28
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Xu R, Feng Q, He Y, Yan F, Chen L, Zhao Y. Dual functionalized poly(vinylidene fluoride) membrane with acryloylmorpholine and argatroban to improve antifouling and hemocompatibility. J Biomed Mater Res A 2016; 105:178-188. [DOI: 10.1002/jbm.a.35892] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2016] [Revised: 08/17/2016] [Accepted: 08/30/2016] [Indexed: 12/26/2022]
Affiliation(s)
- Rui Xu
- State Key Laboratory of Separation Membranes and Membrane Processes; School of Material Science and Engineering, Tianjin Polytechnic University; Tianjin 300387 China
| | - Qianqian Feng
- State Key Laboratory of Separation Membranes and Membrane Processes; School of Material Science and Engineering, Tianjin Polytechnic University; Tianjin 300387 China
| | - Yang He
- State Key Laboratory of Separation Membranes and Membrane Processes; School of Material Science and Engineering, Tianjin Polytechnic University; Tianjin 300387 China
| | - Fanyong Yan
- State Key Laboratory of Separation Membranes and Membrane Processes; School of Environmental and Chemical Engineering, Tianjin Polytechnic University; Tianjin 300387 China
| | - Li Chen
- State Key Laboratory of Separation Membranes and Membrane Processes; School of Material Science and Engineering, Tianjin Polytechnic University; Tianjin 300387 China
- School of Material Science and Engineering; Tianjin University of Technology; Tianjin 300384 China
| | - Yiping Zhao
- State Key Laboratory of Separation Membranes and Membrane Processes; School of Material Science and Engineering, Tianjin Polytechnic University; Tianjin 300387 China
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29
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Lehmann M, Wallbank AM, Dennis KA, Wufsus AR, Davis KM, Rana K, Neeves KB. On-chip recalcification of citrated whole blood using a microfluidic herringbone mixer. BIOMICROFLUIDICS 2015; 9:064106. [PMID: 26634014 PMCID: PMC4654733 DOI: 10.1063/1.4935863] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/11/2015] [Accepted: 11/02/2015] [Indexed: 05/20/2023]
Abstract
In vitro assays of platelet function and coagulation are typically performed in the presence of an anticoagulant. The divalent cation chelator sodium citrate is among the most common because its effect on coagulation is reversible upon reintroduction of divalent cations. Adding divalent cations into citrated blood by batch mixing leads to platelet activation and initiation of coagulation after several minutes, thus limiting the time blood can be used before spontaneously clotting. In this work, we describe a herringbone microfluidic mixer to continuously introduce divalent cations into citrated blood. The mixing ratio, defined as the ratio of the volumetric flow rates of citrated blood and recalcification buffer, can be adjusted by changing the relative inlet pressures of these two solutions. This feature is useful in whole blood assays in order to account for differences in hematocrit, and thus viscosity. The recalcification process in the herringbone mixer does not activate platelets. The advantage of this continuous mixing approach is demonstrated in microfluidic vascular injury model in which platelets and fibrin accumulate on a collagen-tissue factor surface under flow. Continuous recalcification with the herringbone mixer allowed for flow assay times of up to 30 min, more than three times longer than the time achieved by batch recalcification. This continuous mixer allows for measurements of thrombus formation, remodeling, and fibrinolysis in vitro over time scales that are relevant to these physiological processes.
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Affiliation(s)
- Marcus Lehmann
- Chemical and Biological Engineering Department, Colorado School of Mines , Golden, Colorado 80401, USA
| | - Alison M Wallbank
- Chemical and Biological Engineering Department, Colorado School of Mines , Golden, Colorado 80401, USA
| | - Kimberly A Dennis
- Chemical and Biological Engineering Department, Colorado School of Mines , Golden, Colorado 80401, USA
| | - Adam R Wufsus
- Chemical and Biological Engineering Department, Colorado School of Mines , Golden, Colorado 80401, USA
| | - Kara M Davis
- Chemical and Biological Engineering Department, Colorado School of Mines , Golden, Colorado 80401, USA
| | - Kuldeepsinh Rana
- Chemical and Biological Engineering Department, Colorado School of Mines , Golden, Colorado 80401, USA
| | - Keith B Neeves
- Chemical and Biological Engineering Department, Colorado School of Mines , Golden, Colorado 80401, USA
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30
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Li C, Xu J, Ma B. Precise quantitative addition of multiple reagents into droplets in sequence using glass fiber-induced droplet coalescence. Analyst 2015; 140:701-5. [PMID: 25434979 DOI: 10.1039/c4an01852d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Precise quantitative addition of multiple reagents into droplets in sequence is still a bottleneck in droplet-based analysis. To address this issue, we presented a simple and robust glass fiber-induced droplet coalescence method. The hydrophilic glass fiber embedded in the microchannels can induce the deformation of droplets and trigger the coalescence. Serial addition of reagents with controlled volumes was performed by this method without the requirement for an external power source.
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Affiliation(s)
- Chunyu Li
- Single-Cell Center, CAS Key Laboratory of Biofuels and Shandong Key Laboratory of Energy Genetics, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, Shandong 266101, China.
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31
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Niu G, Ruditskiy A, Vara M, Xia Y. Toward continuous and scalable production of colloidal nanocrystals by switching from batch to droplet reactors. Chem Soc Rev 2015; 44:5806-20. [DOI: 10.1039/c5cs00049a] [Citation(s) in RCA: 122] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Droplet reactors serve as a practical platform to the scalable production of colloidal nanocrystals with well-controlled sizes, shapes, and structures.
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Affiliation(s)
- Guangda Niu
- The Wallace H. Coulter Department of Biomedical Engineering
- Georgia Institute of Technology and Emory University
- Atlanta
- USA
- Key Lab of Organic Optoelectronics and Molecular Engineering of Ministry of Education
| | - Aleksey Ruditskiy
- School of Chemistry and Biochemistry
- Georgia Institute of Technology
- Atlanta
- USA
| | - Madeline Vara
- School of Chemistry and Biochemistry
- Georgia Institute of Technology
- Atlanta
- USA
| | - Younan Xia
- The Wallace H. Coulter Department of Biomedical Engineering
- Georgia Institute of Technology and Emory University
- Atlanta
- USA
- School of Chemistry and Biochemistry
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32
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Sun S, Kennedy RT. Droplet electrospray ionization mass spectrometry for high throughput screening for enzyme inhibitors. Anal Chem 2014; 86:9309-14. [PMID: 25137241 PMCID: PMC4165461 DOI: 10.1021/ac502542z] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2014] [Accepted: 08/19/2014] [Indexed: 12/20/2022]
Abstract
High throughput screening (HTS) is important for identifying molecules with desired properties. Mass spectrometry (MS) is potentially powerful for label-free HTS due to its high sensitivity, speed, and resolution. Segmented flow, where samples are manipulated as droplets separated by an immiscible fluid, is an intriguing format for high throughput MS because it can be used to reliably and precisely manipulate nanoliter volumes and can be directly coupled to electrospray ionization (ESI) MS for rapid analysis. In this study, we describe a "MS Plate Reader" that couples standard multiwell plate HTS workflow to droplet ESI-MS. The MS plate reader can reformat 3072 samples from eight 384-well plates into nanoliter droplets segmented by an immiscible oil at 4.5 samples/s and sequentially analyze them by MS at 2 samples/s. Using the system, a label-free screen for cathepsin B modulators against 1280 chemicals was completed in 45 min with a high Z-factor (>0.72) and no false positives (24 of 24 hits confirmed). The assay revealed 11 structures not previously linked to cathepsin inhibition. For even larger scale screening, reformatting and analysis could be conducted simultaneously, which would enable more than 145,000 samples to be analyzed in 1 day.
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Affiliation(s)
- Shuwen Sun
- Department
of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Robert T. Kennedy
- Department
of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
- Department
of Pharmacology, University of Michigan, Ann Arbor, Michigan 48109, United States
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33
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Yu J, Tao D, Ng EX, Drum CL, Liu AQ, Chen CH. Real-time measurement of thrombin generation using continuous droplet microfluidics. BIOMICROFLUIDICS 2014; 8:052108. [PMID: 25332735 PMCID: PMC4189542 DOI: 10.1063/1.4894747] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2014] [Revised: 09/09/2014] [Accepted: 08/23/2014] [Indexed: 05/10/2023]
Abstract
Thrombin, which has the leading role in the blood coagulation cascade, is an important biomarker in hemostasis and cardiovascular disease (CVD) development. In this study, a measurement system capable of continuously monitoring individual thrombin generation using droplet microfluidic technology is manipulated. The thrombin generation assay based on fluogenic substrate is performed within the droplets and the thrombin generation curve of plasma sample activated by tissue factor is measured in real-time to reflect the sample conditions dynamically. The injection of the inhibitor of thrombin generation is developed to assay the inhibited curve which relates to thrombin self-inhibition in biological systems. This microfluidic system is integrated with the microdialysis probe, which is useful to connect to the living animals for future in vivo real time thrombin measurements for rapid CVD diagnosis.
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Affiliation(s)
- Jiaqing Yu
- Department of Biomedical Engineering, National University of Singapore , Singapore 117575
| | - Ding Tao
- Yong Loo Lin School of Medicine, National University of Singapore , Singapore 119228
| | - Ee Xing Ng
- Department of Biomedical Engineering, National University of Singapore , Singapore 117575
| | - Chester L Drum
- Yong Loo Lin School of Medicine, National University of Singapore , Singapore 119228
| | - Ai Qun Liu
- Department of Electrical and Electronic Engineering, Nanyang Technological University , Singapore 639798
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34
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Nightingale AM, Phillips TW, Bannock JH, de Mello JC. Controlled multistep synthesis in a three-phase droplet reactor. Nat Commun 2014; 5:3777. [PMID: 24797034 PMCID: PMC4024758 DOI: 10.1038/ncomms4777] [Citation(s) in RCA: 103] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2013] [Accepted: 04/02/2014] [Indexed: 12/26/2022] Open
Abstract
Channel-fouling is a pervasive problem in continuous flow chemistry, causing poor product control and reactor failure. Droplet chemistry, in which the reaction mixture flows as discrete droplets inside an immiscible carrier liquid, prevents fouling by isolating the reaction from the channel walls. Unfortunately, the difficulty of controllably adding new reagents to an existing droplet stream has largely restricted droplet chemistry to simple reactions in which all reagents are supplied at the time of droplet formation. Here we describe an effective method for repeatedly adding controlled quantities of reagents to droplets. The reagents are injected into a multiphase fluid stream, comprising the carrier liquid, droplets of the reaction mixture and an inert gas that maintains a uniform droplet spacing and suppresses new droplet formation. The method, which is suited to many multistep reactions, is applied to a five-stage quantum dot synthesis wherein particle growth is sustained by repeatedly adding fresh feedstock.
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Affiliation(s)
- Adrian M Nightingale
- 1] Department of Chemistry, Imperial College London, Exhibition Road, South Kensington, London SW7 2AY, UK [2]
| | - Thomas W Phillips
- Department of Chemistry, Imperial College London, Exhibition Road, South Kensington, London SW7 2AY, UK
| | - James H Bannock
- Department of Chemistry, Imperial College London, Exhibition Road, South Kensington, London SW7 2AY, UK
| | - John C de Mello
- Department of Chemistry, Imperial College London, Exhibition Road, South Kensington, London SW7 2AY, UK
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35
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Volný M, Rolfs J, Hakimi B, Fryčák P, Schneider T, Liu D, Yen G, Chiu DT, Tureček F. Nanoliter segmented-flow sampling mass spectrometry with online compartmentalization. Anal Chem 2014; 86:3647-52. [PMID: 24625074 PMCID: PMC3977581 DOI: 10.1021/ac500365r] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
![]()
We report a microfluidic device,
using segmented flow in a two-phase
system of immiscible liquids, which delivers aqueous droplets into
a modified commercial mass spectrometer. The interface coupling the
microfluidics to the mass spectrometer achieves up to 96% sample transfer
efficiency to the vacuum chamber. Sample ionization is assisted by
multipass infrared laser beam in the interface. The system achieves
low femtomole detection limits of several analytes ranging from drugs
to proteins. Sample ionization in this segmented-flow sampling was
found to be remarkably insensitive to the presence of buffer salts
and other matrices.
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Affiliation(s)
- Michael Volný
- Department of Chemistry, University of Washington , Seattle, Washington 98195, United States
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36
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Nie J, Kennedy RT. Capillary liquid chromatography fraction collection and postcolumn reaction using segmented flow microfluidics. J Sep Sci 2013; 36:3471-7. [PMID: 24039151 PMCID: PMC5641422 DOI: 10.1002/jssc.201300725] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2013] [Revised: 08/07/2013] [Accepted: 08/18/2013] [Indexed: 11/08/2022]
Abstract
A challenge for capillary LC (cLC) is fraction collection and the manipulation of fractions from microscale columns. An emerging approach is the use of segmented flow or droplet technology to perform such tasks. In this work, a fraction collection and postcolumn reaction system based on segmented flow was developed for the gradient cLC of proteins. In the system, column effluent and immiscible oil are pumped into separate arms of a tee resulting in regular fractions of effluent segmented by oil. Fractions were generated at 1 Hz corresponding to 5 nL volumes. The fraction collection rate was high enough to generate over 30 fractions per peak and preserve chromatographic resolution achieved for a five-protein test mixture. The resulting fractions could be stored and subsequently derivatized for fluorescence detection by pumping them into a second tee where naphthalene dicarboxyaldehyde, a fluorogenic reagent, was pumped into a second arm and added to each fraction. Proteins were derivatized within the droplets enabling postcolumn fluorescence detection of the proteins. The experiments demonstrate that fraction collection from cLC by segmented flow can be extended to proteins. Further, they illustrate a potential workflow for protein analysis based on postcolumn derivatization for fluorescence detection.
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Affiliation(s)
- Jing Nie
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109
| | - Robert T. Kennedy
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109
- Department of Pharmacology, University of Michigan, Ann Arbor, Michigan 48109
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37
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Castrejón-Pita JR, Kubiak KJ, Castrejón-Pita AA, Wilson MCT, Hutchings IM. Mixing and internal dynamics of droplets impacting and coalescing on a solid surface. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2013; 88:023023. [PMID: 24032939 DOI: 10.1103/physreve.88.023023] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/05/2013] [Indexed: 05/28/2023]
Abstract
The coalescence and mixing of a sessile and an impacting liquid droplet on a solid surface are studied experimentally and numerically in terms of lateral separation and droplet speed. Two droplet generators are used to produce differently colored droplets. Two high-speed imaging systems are used to investigate the impact and coalescence of the droplets in color from a side view with a simultaneous gray-scale view from below. Millimeter-sized droplets were used with dynamical conditions, based on the Reynolds and Weber numbers, relevant to microfluidics and commercial inkjet printing. Experimental measurements of advancing and receding static contact angles are used to calibrate a contact angle hysteresis model within a lattice Boltzmann framework, which is shown to capture the observed dynamics qualitatively and the final droplet configuration quantitatively. Our results show that no detectable mixing occurs during impact and coalescence of similar-sized droplets, but when the sessile droplet is sufficiently larger than the impacting droplet vortex ring generation can be observed. Finally we show how a gradient of wettability on the substrate can potentially enhance mixing.
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Affiliation(s)
- J R Castrejón-Pita
- Department of Engineering, University of Cambridge, 17 Charles Babbage Road, Cambridge CB3 0FS, United Kingdom
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38
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Wang Y, Tumarkin E, Velasco D, Abolhasani M, Lau W, Kumacheva E. Exploring a direct injection method for microfluidic generation of polymer microgels. LAB ON A CHIP 2013; 13:2547-2553. [PMID: 23407698 DOI: 10.1039/c3lc41385c] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Microfluidics (MFs) offers a promising method for the preparation of polymer microgels with exquisite control over their dimensions, shapes and morphologies. A challenging task in this process is the generation of droplets (precursors for microgels) from highly viscous polymer solutions. Spatial separation of MF emulsification and gelation of the precursor droplets on chip can address this challenge. In the present work, we explored the application of the "direct injection" method for the preparation of microgels by adding a highly concentrated polymer solution or a gelling agent directly into the precursor droplets. In the first system, primary droplets were generated from a dilute aqueous solution of agarose, followed by the injection of the concentrated agarose solution directly in the primary droplets. The secondary droplets served as precursors for microgels. In the second system, primary droplets were generated from the low-viscous solution of methyl-β-cyclodextrin and poly(ethylene glycol) end-terminated with octadecyl hydrophobic groups. Addition of surfactant directly into the primary droplets led to the binding of methyl-β-cyclodextrin to the surfactant, thereby releasing hydrophobized poly(ethylene glycol) to form polymer microgels. Our results show that, when optimized, the direct injection method can be used for microgel preparation from highly viscous liquids and thus this method expands the range of polymers used for MF generation of microgels.
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Affiliation(s)
- Yihe Wang
- Department of Chemistry, University of Toronto, Toronto, Ontario M5S 3H6, Canada
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39
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Zhu Y, Fang Q. Analytical detection techniques for droplet microfluidics—A review. Anal Chim Acta 2013; 787:24-35. [DOI: 10.1016/j.aca.2013.04.064] [Citation(s) in RCA: 250] [Impact Index Per Article: 22.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2013] [Revised: 04/27/2013] [Accepted: 04/30/2013] [Indexed: 01/26/2023]
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40
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Abstract
The study of blood ex vivo can occur in closed or open systems, with or without flow. Microfluidic devices, which constrain fluids to a small (typically submillimeter) scale, facilitate analysis of platelet function, coagulation biology, cellular biorheology, adhesion dynamics, and pharmacology and, as a result, can be an invaluable tool for clinical diagnostics. An experimental session can accommodate hundreds to thousands of unique clotting, or thrombotic, events. Using microfluidics, thrombotic events can be studied on defined surfaces of biopolymers, matrix proteins, and tissue factor, under constant flow rate or constant pressure drop conditions. Distinct shear rates can be generated on a device using a single perfusion pump. Microfluidics facilitated both the determination of intraluminal thrombus permeability and the discovery that platelet contractility can be activated by a sudden decrease in flow. Microfluidic devices are ideal for multicolor imaging of platelets, fibrin, and phosphatidylserine and provide a human blood analog to mouse injury models. Overall, microfluidic advances offer many opportunities for research, drug testing under relevant hemodynamic conditions, and clinical diagnostics.
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Affiliation(s)
- Thomas V Colace
- Department of Chemical and Biomolecular Engineering, Institute for Medicine and Engineering, University of Pennsylvania, Philadelphia, PA 19104, USA
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41
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Hatch AC, Patel A, Beer NR, Lee AP. Passive droplet sorting using viscoelastic flow focusing. LAB ON A CHIP 2013; 13:1308-15. [PMID: 23380996 DOI: 10.1039/c2lc41160a] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
We present a study of passive hydrodynamic droplet sorting in microfluidic channels based on intrinsic viscoelastic fluid properties. Sorting is achieved by tuning the droplets' intrinsic viscous and viscoelastic properties relative to the continuous oil phase to achieve a positive or negative lateral migration toward high or low shear gradients in the channel. In the presence of weakly viscoelastic fluid behavior, droplets with a viscosity ratio, κ, between 0.5-10 were found to migrate toward a high shear gradient near the channel walls. For all other κ-values, or Newtonian fluids, droplets would migrate toward a low shear gradient at the channel centerline. It was also found that for strongly viscoelastic fluids with low interfacial tension, droplets would migrate toward the edge even with κ-values lower than 0.5. The resulting bi-directional lateral droplet migration between different droplets allows size-independent sorting. Still, their sorting efficiencies are dependent on droplet size, intrinsic fluid elasticity, viscosity, droplet deformability, and overall fluid shear rates. Based on these findings, we demonstrate >200 Hz passive droplet sorting frequencies and achieve >100 fold enrichment factors without the need to actively sense and/or control active mechanisms. Using a low viscosity oil phase of 6.25 cPs, we demonstrate sorting discrimination of 1 cPs and 5 cPs aqueous droplets with κ-values of 0.2 and 0.8 respectively.
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Affiliation(s)
- Andrew C Hatch
- Biomedical Engineering, University of California-Irvine, CA 92697, USA.
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42
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Luo C, Ma Y, Li H, Chen F, Uchiyama K, Lin JM. Generation of picoliter droplets of liquid for electrospray ionization with piezoelectric inkjet. JOURNAL OF MASS SPECTROMETRY : JMS 2013; 48:321-328. [PMID: 23494787 DOI: 10.1002/jms.3159] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2012] [Revised: 12/08/2012] [Accepted: 12/20/2012] [Indexed: 06/01/2023]
Abstract
We report the association of inkjet and electrospray ionization MS to detect picoliter droplet, where the liquid volume and its position onto the tip can be precisely controlled to form ultrafine droplets for successive ionization of the analyte. Single rectangle pulse was applied to piezoelectric device on inkjet microchip for the ejection of each picoliter droplet, and it was controlled by a computer. The voltage and width of driving pulse for the inkjet were optimized to make reproducible ejection of the solvent with low viscosity. The volume of each droplet was about 600 pl, and a trigger of 10 droplets was selected as the best inlet mode taking relative standard derivation of the droplets into consideration. The target substrate used with high voltage to form ionization was graphite, after several attempts with some materials. High-speed camera was used to capture the breaking-up process of a droplet. The distance between the inkjet nozzle and the tip was set at 2 cm to avoid short circuit. The influences on the mass intensity of the diameter of the tip, the volume and the concentration of the sample were examined. The tip with a small diameter performed greater intensity, and the limit of detection decreased, whereas the small volume of liquid played high ionization efficiency. Linear regression in the range between 1 and 200 ppm for caffeine was conducted, where internal standard theobromine was used. Some real samples were also detected with the instrument.
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Affiliation(s)
- Chen Luo
- Beijing Key Laboratory of Microanalytical Methods and Instrumentation, Department of Chemistry, Tsinghua University, Beijing 100084, China
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43
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Abstract
Droplet-based microfluidics or digital microfluidics is a subclass of microfluidic devices, wherein droplets are generated using active or passive methods. The active method for generation of droplets involves the use of an external factor such as an electric field for droplet generation. Two techniques that fall in this category are dielectrophoresis (DEP) and electrowetting on dielectric (EWOD). In passive methods, the droplet generation depends on the geometry and dimensions of the device. T-junction and flow focusing methods are examples of passive methods used for generation of droplets. In this chapter the methods used for droplet generation, mixing of contents of droplets, and the manipulation of droplets are described in brief. A review of the applications of digital microfluidics with emphasis on the last decade is presented.
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Affiliation(s)
- Sanjiv Sharma
- Institute of Biomedical Engineering & Department of Chemistry, Imperial College, London, UK.
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44
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Meyer Dos Santos S, Zorn A, Guttenberg Z, Picard-Willems B, Kläffling C, Nelson K, Klinkhardt U, Harder S. A novel μ-fluidic whole blood coagulation assay based on Rayleigh surface-acoustic waves as a point-of-care method to detect anticoagulants. BIOMICROFLUIDICS 2013; 7:56502. [PMID: 24404078 PMCID: PMC3799685 DOI: 10.1063/1.4824043] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2013] [Accepted: 09/19/2013] [Indexed: 05/10/2023]
Abstract
A universal coagulation test that reliably detects prolonged coagulation time in patients, irrespective of the anticoagulant administered, has not been available to date. An easily miniaturised, novel μ-fluidic universal coagulation test employing surface acoustic waves (SAW) is presented here. SAW was employed to instantly mix and recalcify 6 μl citrated whole blood and image correlation analysis was used to quantify clot formation kinetics. The detection of clinically relevant anticoagulant dosing with old anticoagulants (unfractionated heparin, argatroban) and new anticoagulants (dabigatran, rivaroxaban) has been tested and compared to standard plasma coagulation assays. The applicability of this novel method has been confirmed in a small patient population. Coagulation was dose-proportionally prolonged with heparin, argatroban, dabigatran, and rivaroxaban, comparable to standard tests. Aspirin and clopidogrel did not interfere with the SAW-induced clotting time (SAW-CT), whereas the strong GPIIb/IIIa-inhibitor abciximab did interfere. Preliminary clinical data prove the suitability of the SAW-CT in patients being treated with warfarin, rivaroxaban, or dabigatran. The system principally allows assessment of whole blood coagulation in humans in a point-of-care setting. This method could be used in stroke units, emergency vehicles, general and intensive care wards, as well as for laboratory and home testing of coagulation.
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Affiliation(s)
- Sascha Meyer Dos Santos
- J.W. Goethe University Hospital, Institute for Clinical Pharmacology, Theodor-Stern-Kai 7 60590 Frankfurt
| | - Anita Zorn
- J.W. Goethe University Hospital, Institute for Clinical Pharmacology, Theodor-Stern-Kai 7 60590 Frankfurt
| | | | - Bettina Picard-Willems
- J.W. Goethe University Hospital, Institute for Clinical Pharmacology, Theodor-Stern-Kai 7 60590 Frankfurt
| | - Christina Kläffling
- J.W. Goethe University Hospital, Center for Internal Medicine-Cardiology, Theodor-Stern-Kai 7 60590 Frankfurt
| | - Karen Nelson
- J.W. Goethe University Hospital, Department of Vascular and Endovascular Surgery, Theodor-Stern-Kai 7 60590 Frankfurt
| | - Ute Klinkhardt
- J.W. Goethe University Hospital, Institute for Clinical Pharmacology, Theodor-Stern-Kai 7 60590 Frankfurt
| | - Sebastian Harder
- J.W. Goethe University Hospital, Institute for Clinical Pharmacology, Theodor-Stern-Kai 7 60590 Frankfurt
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45
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Sun M, Khan ZS, Vanapalli SA. Blood plasma separation in a long two-phase plug flowing through disposable tubing. LAB ON A CHIP 2012; 12:5225-30. [PMID: 23114925 DOI: 10.1039/c2lc40544j] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
We report a simple technique to separate plasma from blood in a flowing immiscible plug. We investigate the effect of various control parameters such as blood dilution, injection flow rate, observation time and fluid properties on plasma separation. We find that the technique works best for diluted blood samples at low plug velocities and long observation times. We postulate that the main mechanism responsible for efficient separation is the sedimentation of blood cells in the plug and their subsequent collection by the moving plug causing a significant accumulation of cells at the rear of the plug. We discuss the time scales determining the sedimentation, advection and collection of a blood cell in the immiscible plug and propose a phase diagram that is able to predict the operating space for effective plasma separation. We demonstrate that the technique allows for the extraction of more than 60% of the plasma by volume from 1 μL of diluted blood. We show the practical significance of this method by compartmentalizing the separated plasma into discrete microfluidic droplets and detecting cholesterol. This technique features low consumption of blood (nL-scale) and low shear rate (∼1 s(-1)). It is inexpensive, easy to use, and has the potential to be developed as an efficient point-of-care device for blood diagnostics in resource-poor environments. More advanced applications could also be envisioned by integrating our plasma separation method into existing microfluidic drop manipulation techniques.
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Affiliation(s)
- Meng Sun
- Department of Chemical Engineering, Texas Tech University, Lubbock, TX 79409-3121, USA
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46
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Kaltenbach M, Devenish SRA, Hollfelder F. A simple method to evaluate the biochemical compatibility of oil/surfactant mixtures for experiments in microdroplets. LAB ON A CHIP 2012; 12:4185-92. [PMID: 22885600 DOI: 10.1039/c2lc40281e] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
The enormous reduction of assay volume afforded by compartmentalization into picolitre water-in-oil droplets is an exciting prospect for high-throughput biology. Maintaining the activity of encapsulated proteins is critical for experimental success, for example in in vitro directed evolution, where protein variants are expressed in droplets to identify mutants with improved properties. Here, we present a simple and rapid method to quantitatively compare concentrations of fluorescent molecules in microdroplets. This approach allows an assessment of different emulsification procedures and several oil/surfactant mixtures for biochemical compatibility, in particular in vitro protein expression. Based on determining droplet fluorescence vs. droplet diameter, the method uses the gradient of such curves as a 'concentration correlation coefficient' (CCC) that is directly proportional to fluorophore concentration. Our findings suggest that generation of droplets using a microfluidic flow-focusing device gave no more protein expression than droplet production by the bulk methods of vortexing and homogenizing. The choice of oil/surfactant, however, was found to be critical for protein expression and even encapsulation of purified protein, highlighting the importance of careful selection of these components when carrying out biochemical experiments in droplets. This methodology will serve as a quantitative test for the rapid optimization of droplet-based experiments such as in vitro protein expression or enzymatic assays.
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Affiliation(s)
- Miriam Kaltenbach
- Department of Biochemistry, University of Cambridge, 80 Tennis Court Road, CB2 1GA, Cambridge, UK
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47
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Abstract
In the present paper, we review and discuss current developments and challenges in the field of droplet-based microfluidics. This discussion includes an assessment of the basic fluid dynamics of segmented flows, material requirements, fundamental unit operations and how integration of functional components can be applied to specific biological problems.
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48
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Sun S, Slaney TR, Kennedy RT. Label free screening of enzyme inhibitors at femtomole scale using segmented flow electrospray ionization mass spectrometry. Anal Chem 2012; 84:5794-800. [PMID: 22656268 DOI: 10.1021/ac3011389] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Droplet-based microfluidics is an attractive platform for screening and optimizing chemical reactions. Using this approach, it is possible to reliably manipulate nanoliter volume samples and perform operations such as reagent addition with high precision, automation, and throughput. Most studies using droplet microfluidics have relied on optical techniques to detect the reaction; however, this requires engineering color or fluorescence change into the reaction being studied. In this work, we couple electrospray ionization mass spectrometry (ESI-MS) to nanoliter scale segmented flow reactions to enable direct (label-free) analysis of reaction products. The system is applied to a screen of inhibitors for cathepsin B. In this approach, solutions of test compounds (including three known inhibitors) are arranged as an array of nanoliter droplets in a tube segmented by perfluorodecalin. The samples are pumped through a series of tees to add enzyme, substrate (peptides), and quenchant. The resulting reaction mixtures are then infused into a metal-coated, fused silica ESI emitter for MS analysis. The system has potential for high-throughput as reagent addition steps are performed at 0.7 s per sample and ESI-MS at up to 1.2 s per sample. Carryover is inconsequential in the ESI emitter and between 2 and 9% per reagent addition depending on the tee utilized. The assay was reliable with a Z-factor of ~0.8. The method required 0.8 pmol of test compound, 1.6 pmol of substrate, and 5 fmol of enzyme per reaction. Segmented flow ESI-MS allows direct, label free screening of reactions at good throughput and ultralow sample consumption.
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Affiliation(s)
- Shuwen Sun
- University of Michigan, Department of Chemistry, Ann Arbor, Michigan 48109, United States
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49
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Wang K, Lu Y, Yang L, Luo G. Microdroplet coalescences at microchannel junctions with different collision angles. AIChE J 2012. [DOI: 10.1002/aic.13825] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Kai Wang
- Dept. of Chemical Engineering; The State Key Laboratory of Chemical Engineering; Tsinghua University; Beijing; 100084; People's Republic of China
| | - Yangcheng Lu
- Dept. of Chemical Engineering; The State Key Laboratory of Chemical Engineering; Tsinghua University; Beijing; 100084; People's Republic of China
| | - Lu Yang
- Dept. of Chemical Engineering; The State Key Laboratory of Chemical Engineering; Tsinghua University; Beijing; 100084; People's Republic of China
| | - Guangsheng Luo
- Dept. of Chemical Engineering; The State Key Laboratory of Chemical Engineering; Tsinghua University; Beijing; 100084; People's Republic of China
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50
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Choi JW, Kang DK, Park H, deMello AJ, Chang SI. High-Throughput Analysis of Protein–Protein Interactions in Picoliter-Volume Droplets Using Fluorescence Polarization. Anal Chem 2012; 84:3849-54. [DOI: 10.1021/ac300414g] [Citation(s) in RCA: 80] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Affiliation(s)
- Jae-Won Choi
- Department of Biochemistry, Chungbuk National University, Cheongju 361-763, Republic
of Korea,
| | - Dong-Ku Kang
- Department of Biochemistry, Chungbuk National University, Cheongju 361-763, Republic
of Korea,
- Department of
Chemistry, Imperial College London, London
SW7 2AZ, United Kingdom,
| | - Hyun Park
- Department of Biochemistry, Chungbuk National University, Cheongju 361-763, Republic
of Korea,
| | - Andrew J. deMello
- Department of Chemistry and Applied Biosciences, ETH Zürich, Zürich CH-8093, Switzerland
| | - Soo-Ik Chang
- Department of Biochemistry, Chungbuk National University, Cheongju 361-763, Republic
of Korea,
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