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Zhou C, Zhu P, Tian Y, Shi R, Wang L. Progress in all-aqueous droplets generation with microfluidics: Mechanisms of formation and stability improvements. BIOPHYSICS REVIEWS 2022; 3:021301. [PMID: 38505416 PMCID: PMC10914135 DOI: 10.1063/5.0054201] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/29/2021] [Accepted: 01/27/2022] [Indexed: 03/21/2024]
Abstract
All-aqueous systems have attracted intensive attention as a promising platform for applications in cell separation, protein partitioning, and DNA extraction, due to their selective separation capability, rapid mass transfer, and good biocompatibility. Reliable generation of all-aqueous droplets with accurate control over their size and size distribution is vital to meet the increasingly growing demands in emulsion-based applications. However, the ultra-low interfacial tension and large effective interfacial thickness of the water-water interface pose challenges for the generation and stabilization of uniform all-aqueous droplets, respectively. Microfluidics technology has emerged as a versatile platform for the precision generation of all-aqueous droplets with improved stability. This review aims to systematize the controllable generation of all-aqueous droplets and summarize various strategies to improve their stability with microfluidics. We first provide a comprehensive review on the recent progress of all-aqueous droplets generation with microfluidics by detailing the properties of all-aqueous systems, mechanisms of droplet formation, active and passive methods for droplet generation, and the property of droplets. We then review the various strategies used to improve the stability of all-aqueous droplets and discuss the fabrication of biomaterials using all-aqueous droplets as liquid templates. We envision that this review will benefit the future development of all-aqueous droplet generation and its applications in developing biomaterials, which will be useful for researchers working in the field of all-aqueous systems and those who are new and interested in the field.
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Affiliation(s)
| | - Pingan Zhu
- Department of Mechanical Engineering, City University of Hong Kong, Hong Kong, China
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2
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Sano H, Kazoe Y, Kitamori T. Stable Formation of Aqueous/Organic Parallel Two-phase Flow in Nanochannels with Partial Surface Modification. ANAL SCI 2021; 37:1611-1616. [PMID: 34054008 DOI: 10.2116/analsci.21p138] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
In microfluidics, various chemical processes can be integrated utilizing parallel multiphase flows. Our group has extended this research to nanofluidics, and recently performed the extraction of lipids using parallel two-phase flow in nanochannels. Although this was achieved in surface-modified nanochannels, a stable condition of parallel two-phase flow remains unknown due to difficulties in device fabrication, for a suitable method of bonding surface-modified substrates is lacking. Therefore, research on parallel two-phase flow in nanochannels has been limited. Herein, a new bonding method which improves the wash process for the substrates and increases the bonding rate to ∼100% is described. The conditions to achieve parallel organic/aqueous two-phase flow were then studied. It was revealed that in nanochannels, higher capillary numbers for the organic phase flow were required compared to that in microchannels. The newly developed fabrication process and flow regimes will contribute to realize integrated nanofluidic devices capable of analyzing single molecules/cells.
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Affiliation(s)
- Hiroki Sano
- Department of Applied Chemistry, School of Engineering, The University of Tokyo
| | - Yutaka Kazoe
- Department of Applied Chemistry, School of Engineering, The University of Tokyo.,Department of System Design Engineering, Faculty of Science and Technology, Keio University
| | - Takehiko Kitamori
- Department of Applied Chemistry, School of Engineering, The University of Tokyo.,Collaborative Research Organization for Micro and Nano Multifunctional Devices, The University of Tokyo.,Institute of NanoEngineering and MicroSystems, Department of Power Mechanical Engineering, National Tsing Hua University
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3
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Kee PE, Yim HS, Kondo A, Lan JCW, Ng HS. Evaluation of Aqueous Biphasic Electrophoresis System Based on Halide-Free Ionic Liquids for Direct Recovery of Keratinase. Mar Drugs 2021; 19:463. [PMID: 34436302 PMCID: PMC8398788 DOI: 10.3390/md19080463] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2021] [Revised: 08/11/2021] [Accepted: 08/12/2021] [Indexed: 11/17/2022] Open
Abstract
Aqueous biphasic electrophoresis system (ABES) incorporates electric fields into the biphasic system to separate the target biomolecules from crude feedstock. Ionic liquid (IL) is regarded as an excellent candidate as the phase-forming components for ABES because of the great electrical conductivity, which can promote the electromigration of biomolecules in ABES, and thereby enhances the separation efficiency of the target biomolecules from crude feedstock. The application of electric fields to the conventional biphasic system expedites the phase settling time of the biphasic system, which eases the subsequent scaling-up steps and reduces the overall processing time of the recovery process. Alkyl sulphate-based IL is a green and economical halide-free surfactant when compared to the other halide-containing IL. The feasibility of halide-free IL-based ABES to recover Kytococcus sedentarius TWHK01 keratinase was studied. Optimum partition coefficient (Ke = 7.53 ± 0.35) and yield (YT = 80.36% ± 0.71) were recorded with IL-ABES comprised of 15.0% (w/w) [EMIM][ESO4], 20.0% (w/w) sodium carbonate and 15% (w/w) crude feedstock. Selectivity (S) of 5.75 ± 0.27 was obtained with the IL-ABES operated at operation time of 5 min with 10 V voltage supplied. Halide-free IL is proven to be a potential phase-forming component of IL-ABES for large-scale recovery of keratinase.
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Affiliation(s)
- Phei Er Kee
- Faculty of Applied Sciences, UCSI University, UCSI Heights, Cheras, Kuala Lumpur 56000, Malaysia; (P.E.K.); (H.S.Y.)
- Biorefinery and Bioprocess Engineering Laboratory, Department of Chemical Engineering and Materials Science, Yuan Ze University, Chungli, Taoyuan 320, Taiwan
| | - Hip Seng Yim
- Faculty of Applied Sciences, UCSI University, UCSI Heights, Cheras, Kuala Lumpur 56000, Malaysia; (P.E.K.); (H.S.Y.)
| | - Akihiko Kondo
- Department of Chemical Science and Engineering, Graduate School of Engineering, Kobe University, 1-1 Rokkodai, Nada, Kobe 657-8501, Japan;
| | - John Chi-Wei Lan
- Biorefinery and Bioprocess Engineering Laboratory, Department of Chemical Engineering and Materials Science, Yuan Ze University, Chungli, Taoyuan 320, Taiwan
- Graduate School of Biotechnology and Bioengineering, Yuan Ze University, No. 135 Yuan-Tung Road, Chungli, Taoyuan 320, Taiwan
| | - Hui Suan Ng
- Faculty of Applied Sciences, UCSI University, UCSI Heights, Cheras, Kuala Lumpur 56000, Malaysia; (P.E.K.); (H.S.Y.)
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Incorporation of electric fields to ionic liquids-based aqueous biphasic system for enhanced recovery of extracellular Kytococcus sedentarius TWHKC01 keratinase. J Taiwan Inst Chem Eng 2021. [DOI: 10.1016/j.jtice.2021.06.009] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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5
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Gebhard F, Hartmann J, Hardt S. Interaction of proteins with phase boundaries in aqueous two-phase systems under electric fields. SOFT MATTER 2021; 17:3929-3936. [PMID: 33720237 DOI: 10.1039/d0sm01921f] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
The electric-field driven transport of proteins across the liquid-liquid interface in an aqueous two-phase system (ATPS) is studied in a microfluidic device using fluorescence microscopy. An ATPS containing polyethylene glycol (PEG) and dextran is employed, and bovine serum albumin (BSA) and bovine γ-globulins (BγG) are considered as model proteins. It is shown that both proteins, initially in the dextran-rich phase, accumulate at the liquid-liquid interface, preferably close to the three-phase contact line between the two liquid phases and the microchannel wall. It is in these regions where the proteins penetrate into the PEG-rich phase. The transport resistance of the liquid-liquid interface is higher for BγG than for BSA, such that a much larger molar flux of BSA into the PEG phase is observed. This opens up the opportunity of separating different protein species by utilizing differences in the transport resistance at the interface. A mathematical model is developed, accounting for adsorption and desorption processes at the liquid-liquid interface. The underlying theoretical concept is that of an electrostatic potential minimum formed by superposing the applied electric field and the field due to the Donnan potential at the interface. A fit of the model parameters to the experimental data results in good agreement between theory and experiments, thereby corroborating the underlying picture.
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Affiliation(s)
- Florian Gebhard
- Technische Universität Darmstadt, Fachbereich Maschinenbau, Alarich-Weiss-Str. 10, 64287 Darmstadt, Germany.
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6
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Li M, Li D. Electrically controllable cargo delivery with dextran-rich droplets. J Colloid Interface Sci 2021; 582:102-111. [PMID: 32814218 DOI: 10.1016/j.jcis.2020.08.033] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Revised: 08/03/2020] [Accepted: 08/08/2020] [Indexed: 11/25/2022]
Abstract
The controllable delivery of cargo is of great importance in many areas, ranging from medicine and materials science to food and cosmetic industries. To fulfil the requirements in different areas, the development of new methods for cargo delivery in a controllable manner is always essential. A novel technique of cargo delivery controlled by electric pulse was developed in this paper. In an aqueous two-phase system, the dextran-rich droplets were fabricated as droplet carriers in a continuous polyethylene glycol-rich phase. The loading and releasing of model cargos (polystyrene particles) across the surface of the droplet carriers under electric pulses were demonstrated in microfluidic chips. By controlling the amplitude of the applied electric pulses, the cargos with designed sizes were sorted and loaded into the droplet carriers; hence, the targeted delivery of cargos by size can be achieved. The exchange of cargos between droplet carriers under reversed electric pulses was also investigated, and the results indicated the flexibility of this method in cargo delivery. Moreover, possible application of this method to biological cargos was demonstrated by controlling the loading and releasing of yeast cells under electric pulses. With the advantages of easy operation and fast response, this approach provides a novel route for controllable cargo delivery with droplets.
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Affiliation(s)
- Mengqi Li
- Department of Marine Engineering, Dalian Maritime University, Dalian 116026, China; Department of Mechanical and Mechatronics Engineering, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada
| | - Dongqing Li
- Department of Mechanical and Mechatronics Engineering, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada.
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7
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Chao Y, Shum HC. Emerging aqueous two-phase systems: from fundamentals of interfaces to biomedical applications. Chem Soc Rev 2020; 49:114-142. [DOI: 10.1039/c9cs00466a] [Citation(s) in RCA: 138] [Impact Index Per Article: 34.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
This review summarizes recent advances of aqueous two-phase systems (ATPSs), particularly their interfaces, with a focus on biomedical applications.
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Affiliation(s)
- Youchuang Chao
- Department of Mechanical Engineering
- The University of Hong Kong
- China
| | - Ho Cheung Shum
- Department of Mechanical Engineering
- The University of Hong Kong
- China
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8
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Mařík K, Tichá L, Vobecká L, Přibyl M. Theoretical study on enzyme synthesis of cephalexin in a parallel-flow microreactor combined with electrically driven ATPS microextraction. REACT CHEM ENG 2020. [DOI: 10.1039/c9re00482c] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A mathematical model of a microfluidic device with two aqueous phases for the simultaneous cephalexin production and its separation from a reaction mixture was developed. The model anticipates the continuous cephalexin synthesis and enzyme recyclation.
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Affiliation(s)
- Karel Mařík
- Department of Chemical Engineering
- University of Chemistry and Technology, Prague
- 166 28 Praha 6
- Czech Republic
| | - Linda Tichá
- Department of Chemical Engineering
- University of Chemistry and Technology, Prague
- 166 28 Praha 6
- Czech Republic
| | - Lucie Vobecká
- Department of Chemical Engineering
- University of Chemistry and Technology, Prague
- 166 28 Praha 6
- Czech Republic
| | - Michal Přibyl
- Department of Chemical Engineering
- University of Chemistry and Technology, Prague
- 166 28 Praha 6
- Czech Republic
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9
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Nahar MM, Moon H. Phase separation of multiphase droplets in a digital microfluidic device. MICRO AND NANO SYSTEMS LETTERS 2019. [DOI: 10.1186/s40486-019-0099-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Abstract
This study reports the first comprehensive investigation of separation of the immiscible phases of multiphase droplets in digital microfluidics (DMF) platform. Electrowetting-on-dielectric (EWOD) actuation has been used to mechanically separate the phases. Phase separation performance in terms of percentage residue of one phase into another phase has been quantified. It was conceived that the residue formation can be controlled by controlling the deformation of the phases. The larger capillary number of the neck forming phase is associated with the larger amount of deformation as well as more residue. In this study, we propose two different ways to control the deformation of the phases. In the first method, we applied different EWOD operation voltages on two phases to maintain equal capillary numbers during phase separation. In the second method, while keeping the applied voltages same on both sides, we tested the phase separation performance by varying the actuation schemes. Less than 2% of residue was achieved by both methods, which is almost 90% improvement compared to the phase separation by the conventional droplet splitting technique in EWOD DMF platform, where the residue percentage can go up to 20%.
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10
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Separation efficiency of parallel flow microfluidic extractors with transport enhanced by electric field. Sep Purif Technol 2019. [DOI: 10.1016/j.seppur.2019.03.089] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
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11
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Choi D, Lee E, Kim SJ, Han M. Passive droplet generation in aqueous two-phase systems with a variable-width microchannel. SOFT MATTER 2019; 15:4647-4655. [PMID: 31073554 DOI: 10.1039/c9sm00469f] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Passive droplet generation for an aqueous two-phase system (ATPS) was performed with a fracture-based variable microchannel. A jet of dextran-rich phase (DEX) in a polyethylene-glycol (PEG)-rich phase was created by focused flow. The width of the inlet channel could be varied over the range 1-10 μm via mechanical strain, which extended the range of operational back pressure. This enabled the spontaneous formation of DEX droplets with an ultralow surface tension of 12 μN m-1. The production of DEX droplets were examined with regard to driving pressure, flow rate, DEX/PEG concentration. The droplet properties are analyzed in terms of production rate (2-20 droplets per s), droplet diameter (10-100 μm), and diameter variance (5-20%). Controlling the inlet-channel width with other operating conditions widened the range of droplet properties. This simple and robust method significantly strengthened droplet-generation in microfluidics, especially for ATPS of low solute concentrations relevant to live cells.
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Affiliation(s)
- Daeho Choi
- Mechanical Engineering, Incheon National University, Incheon, 22012, Korea.
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12
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Vobecká L, Romanov A, Slouka Z, Hasal P, Přibyl M. Optimization of aqueous two-phase systems for the production of 6-aminopenicillanic acid in integrated microfluidic reactors-separators. N Biotechnol 2018; 47:73-79. [PMID: 29614323 DOI: 10.1016/j.nbt.2018.03.005] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2017] [Revised: 03/29/2018] [Accepted: 03/29/2018] [Indexed: 01/27/2023]
Abstract
Aqueous two-phase systems (ATPSs) were screened for the production of 6-aminopenicillanic acid (6-APA) catalyzed by penicillin acylase, followed by the extractive separation of 6-APA from the reaction mixture. The key point of this study was to find an ATPS exhibiting a large difference in the partition coefficients of the biocatalyst and reaction products. Several ATPSs based on polyethylene glycol (PEG)/phosphate, PEG/citrate, and PEG/dextran were tested. We found that an ATPS consisting of 15 wt% of PEG 4000, 10 wt% of phosphates, 75 wt% of water (pH value 8.0 after dissolution) provided optimal separation of 6-APA from the enzyme. While the 6-APA was mainly found in the top PEG phase, the free enzyme favored the bottom salt-rich phase. This ATPS also fulfils other important requirements: (i) high buffering capacity, reducing an undesirable pH decrease due to the dissociation of phenylacetic acid (the side product of the reaction), (ii) a relatively low cost of the ATPS components, (iii) the possibility of electrophoretic transport of fine droplets as well as the reaction products for both the acceleration of phase separation and the enhancement of 6-APA concentration in the product stream. Extraction experiments in microcapillary and batch systems showed that the transport of 6-APA formed in the salt-rich phase to the corresponding PEG phase could occur within 30 s. The experimental results described form a base of knowledge for the development of continuously operating integrated microfluidic reactors-separators driven by an electric field for the efficient production of 6-APA.
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Affiliation(s)
- Lucie Vobecká
- University of Chemistry and Technology, Prague, Department of Chemical Engineering, Technická 5, 166 28 Praha 6, Czech Republic.
| | - Alexandr Romanov
- University of Chemistry and Technology, Prague, Department of Chemical Engineering, Technická 5, 166 28 Praha 6, Czech Republic.
| | - Zdeněk Slouka
- University of Chemistry and Technology, Prague, Department of Chemical Engineering, Technická 5, 166 28 Praha 6, Czech Republic.
| | - Pavel Hasal
- University of Chemistry and Technology, Prague, Department of Chemical Engineering, Technická 5, 166 28 Praha 6, Czech Republic.
| | - Michal Přibyl
- University of Chemistry and Technology, Prague, Department of Chemical Engineering, Technická 5, 166 28 Praha 6, Czech Republic.
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13
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Teixeira AG, Agarwal R, Ko KR, Grant‐Burt J, Leung BM, Frampton JP. Emerging Biotechnology Applications of Aqueous Two-Phase Systems. Adv Healthc Mater 2018; 7:e1701036. [PMID: 29280350 DOI: 10.1002/adhm.201701036] [Citation(s) in RCA: 54] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2017] [Revised: 10/30/2017] [Indexed: 02/06/2023]
Abstract
Liquid-liquid phase separation between aqueous solutions containing two incompatible polymers, a polymer and a salt, or a polymer and a surfactant, has been exploited for a wide variety of biotechnology applications throughout the years. While many applications for aqueous two-phase systems fall within the realm of separation science, the ability to partition many different materials within these systems, coupled with recent advances in materials science and liquid handling, has allowed bioengineers to imagine new applications. This progress report provides an overview of the history and key properties of aqueous two-phase systems to lend context to how these materials have progressed to modern applications such as cellular micropatterning and bioprinting, high-throughput 3D tissue assembly, microscale biomolecular assay development, facilitation of cell separation and microcapsule production using microfluidic devices, and synthetic biology. Future directions and present limitations and design considerations of this adaptable and promising toolkit for biomolecule and cellular manipulation are further evaluated.
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Affiliation(s)
- Alyne G. Teixeira
- School of Biomedical Engineering Dalhousie University 5981 University Avenue Halifax NS B3H 4R2 Canada
| | - Rishima Agarwal
- School of Biomedical Engineering Dalhousie University 5981 University Avenue Halifax NS B3H 4R2 Canada
| | - Kristin Robin Ko
- School of Biomedical Engineering Dalhousie University 5981 University Avenue Halifax NS B3H 4R2 Canada
| | - Jessica Grant‐Burt
- School of Biomedical Engineering Dalhousie University 5981 University Avenue Halifax NS B3H 4R2 Canada
| | - Brendan M. Leung
- School of Biomedical Engineering Dalhousie University 5981 University Avenue Halifax NS B3H 4R2 Canada
- Department of Applied Oral Science Dalhousie University 5981 University Avenue Halifax NS B3H 4R2 Canada
| | - John P. Frampton
- School of Biomedical Engineering Dalhousie University 5981 University Avenue Halifax NS B3H 4R2 Canada
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14
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Saar KL, Zhang Y, Müller T, Kumar CP, Devenish S, Lynn A, Łapińska U, Yang X, Linse S, Knowles TPJ. On-chip label-free protein analysis with downstream electrodes for direct removal of electrolysis products. LAB ON A CHIP 2017; 18:162-170. [PMID: 29192926 DOI: 10.1039/c7lc00797c] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The ability to apply highly controlled electric fields within microfluidic devices is valuable as a basis for preparative and analytical processes. A challenge encountered in the context of such approaches in conductive media, including aqueous buffers, is the generation of electrolysis products at the electrode/liquid interface which can lead to contamination, perturb fluid flows and generally interfere with the measurement process. Here, we address this challenge by designing a single layer microfluidic device architecture where the electric potential is applied outside and downstream of the microfluidic device while the field is propagated back to the chip via the use of a co-flowing highly conductive electrolyte solution that forms a stable interface at the separation region of the device. The co-flowing electrolyte ensures that all the generated electrolysis products, including Joule heat and gaseous products, are flowed away from the chip without coming into contact with the analytes while the single layer fabrication process where all the structures are defined lithographically allows producing the devices in a simple yet highly reproducible manner. We demonstrate that by allowing stable and effective application of electric fields in excess of 100 V cm-1, the described platform provides the basis for rapid separation of heterogeneous mixtures of proteins and protein complexes directly in their native buffers as well as for the simultaneous quantification of their charge states. We illustrate this by probing the interactions in a mixture of an amyloid forming protein, amyloid-β, and a molecular chaperone, Brichos, known to inhibit the process of amyloid formation. The availability of a platform for applying stable electric fields and its compatibility with single-layer soft-lithography processes opens up the possibility of separating and analysing a wide range of molecules on chip, including those with similar electrophoretic mobilities.
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Affiliation(s)
- Kadi L Saar
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, UK.
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15
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Mastiani M, Seo S, Jimenez SM, Petrozzi N, Kim MM. Flow regime mapping of aqueous two-phase system droplets in flow-focusing geometries. Colloids Surf A Physicochem Eng Asp 2017. [DOI: 10.1016/j.colsurfa.2017.07.083] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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16
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Zhou C, Zhu P, Tian Y, Tang X, Shi R, Wang L. Microfluidic generation of aqueous two-phase-system (ATPS) droplets by oil-droplet choppers. LAB ON A CHIP 2017; 17:3310-3317. [PMID: 28861566 DOI: 10.1039/c7lc00696a] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Existing approaches for droplet generation with an ultra-low interfacial tension using aqueous two-phase systems, ATPS, are either constricted by a narrow range of flow conditions using passive methods or subjected to complex chip fabrication with the integration of external components using active actuation. To address these issues, we present a simple approach to produce uniform ATPS droplets facilitated by oil-droplet choppers in microfluidics. Our solution counts on the synchronized formation of high-interfacial-tension oil-in-water and low-interfacial-tension water-in-water droplets, where the ATPS interface is distorted by oil droplets and decays into water-in-water droplets. In the synchronization regime, the size and generation frequency of ATPS droplets can be controlled independently by tuning the flow rates of the dispersed aqueous and oil phases, respectively. Our method demonstrates high uniformity of droplets (coefficient of variation between 0.75% and 2.45%), a wide range of available droplet size (droplet radius from 5 μm to 180 μm), and a maximum generation frequency of about 2.1 kHz that is nearly two orders of magnitude faster than that in existing methods. We develop theoretical models to precisely predict the minimum and maximum frequencies of droplet generation and the droplet size. The produced ATPS droplets and oil choppers are separated in the channel using density difference. Our method would boost emulsion-based biological applications such as cell encapsulation, biomolecule delivery, bioreactors, and biomaterials synthesis with ATPS droplets.
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Affiliation(s)
- Chunmei Zhou
- Department of Mechanical Engineering, The University of Hong Kong, Hong Kong, China.
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17
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18
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19
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Soares RRG, Silva DFC, Fernandes P, Azevedo AM, Chu V, Conde JP, Aires-Barros MR. Miniaturization of aqueous two-phase extraction for biological applications: From micro-tubes to microchannels. Biotechnol J 2016; 11:1498-1512. [PMID: 27624685 DOI: 10.1002/biot.201600356] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2016] [Revised: 07/20/2016] [Accepted: 07/25/2016] [Indexed: 01/26/2023]
Abstract
Aqueous two-phase extraction (ATPE) is a biocompatible liquid-liquid (L-L) separation technique that has been under research for several decades towards the purification of biomolecules, ranging from small metabolites to large animal cells. More recently, with the emergence of rapid-prototyping techniques for fabrication of microfluidic structures with intricate designs, ATPE gained an expanded range of applications utilizing physical phenomena occurring exclusively at the microscale. Today, research is being carried simultaneously in two different volume ranges, mL-scale (microtubes) and nL-scale (microchannels). The objective of this review is to give insight into the state of the art at both microtube and microchannel-scale and to analyze whether miniaturization is currently a competing or divergent technology in a field of applications including bioseparation, bioanalytics, enhanced fermentation processes, catalysis, high-throughput screening and physical/chemical compartmentalization. From our perspective, both approaches are worthy of investigation and, depending on the application, it is likely that either (i) one of the approaches will eventually become obsolete in particular research areas such as purification at the preparative scale or high-throughput screening applications; or (ii) both approaches will function as complementing techniques within the bioanalytics field.
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Affiliation(s)
- Ruben R G Soares
- Instituto de Engenharia de Sistemas e Computadores - Microsistemas e Nanotecnologias (INESC MN) and IN - Institute of Nanoscience and Nanotechnology, Lisbon, Portugal.,IBB - Institute for Bioengineering and Biosciences, Instituto Superior Técnico, Universidade de Lisboa, Lisbon, Portugal
| | - Daniel F C Silva
- Instituto de Engenharia de Sistemas e Computadores - Microsistemas e Nanotecnologias (INESC MN) and IN - Institute of Nanoscience and Nanotechnology, Lisbon, Portugal.,IBB - Institute for Bioengineering and Biosciences, Instituto Superior Técnico, Universidade de Lisboa, Lisbon, Portugal
| | - Pedro Fernandes
- IBB - Institute for Bioengineering and Biosciences, Instituto Superior Técnico, Universidade de Lisboa, Lisbon, Portugal.,Department of Bioengineering, Instituto Superior Técnico, Universidade de Lisboa, Lisbon, Portugal
| | - Ana M Azevedo
- IBB - Institute for Bioengineering and Biosciences, Instituto Superior Técnico, Universidade de Lisboa, Lisbon, Portugal.,Department of Bioengineering, Instituto Superior Técnico, Universidade de Lisboa, Lisbon, Portugal
| | - Virginia Chu
- Instituto de Engenharia de Sistemas e Computadores - Microsistemas e Nanotecnologias (INESC MN) and IN - Institute of Nanoscience and Nanotechnology, Lisbon, Portugal
| | - João P Conde
- Instituto de Engenharia de Sistemas e Computadores - Microsistemas e Nanotecnologias (INESC MN) and IN - Institute of Nanoscience and Nanotechnology, Lisbon, Portugal.,Department of Bioengineering, Instituto Superior Técnico, Universidade de Lisboa, Lisbon, Portugal
| | - M Raquel Aires-Barros
- IBB - Institute for Bioengineering and Biosciences, Instituto Superior Técnico, Universidade de Lisboa, Lisbon, Portugal.,Department of Bioengineering, Instituto Superior Técnico, Universidade de Lisboa, Lisbon, Portugal
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21
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Vázquez-Villegas P, Ouellet E, González C, Ruiz-Ruiz F, Rito-Palomares M, Haynes CA, Aguilar O. A microdevice assisted approach for the preparation, characterization and selection of continuous aqueous two-phase systems: from micro to bench-scale. LAB ON A CHIP 2016; 16:2662-2672. [PMID: 27302418 DOI: 10.1039/c6lc00333h] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Aqueous two-phase systems (ATPS) have emerged as an alternative strategy for the recovery and purification of a wide variety of biological products. Typical process development requires a large screening of experimental conditions towards industrial adoption where continuous processes are preferred. In this work, it was proved that under certain flow conditions, ATPS could be formed continuously inside a microchannel, starting from stocks of phase components. Staggered herringbone chaotic micromixers included within the device sequentially and rapidly prepare two-phase systems across an entire range of useful phase compositions. Two-phase diagrams (binodal curves) were easily plotted using the cloud-point method for systems of different components and compared with previously reported curves for each system, proving that phase formation inside the device correlated with the previously reported diagrams. A proof of concept for sample partitioning in such a microdevice was performed with two different experimental models: BSA and red blood cells. Finally, the microdevice was employed to obtain information about the recovery and partition coefficient of invertase from a real complex mixture of proteins (yeast extract) to design a process for the recovery of the enzyme selecting a suitable system and composition to perform the process at bench-scale.
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Affiliation(s)
- Patricia Vázquez-Villegas
- Escuela de Ingeniería y Ciencias, Tecnologico de Monterrey, Ave. Eugenio Garza Sada 2501, Monterrey, N.L. 64849, Mexico.
| | - Eric Ouellet
- Michael Smith Laboratories, University of British Columbia, Vancouver, BC, V6T 1Z4 Canada
| | - Claudia González
- Escuela de Ingeniería y Ciencias, Tecnologico de Monterrey, Ave. Eugenio Garza Sada 2501, Monterrey, N.L. 64849, Mexico.
| | - Federico Ruiz-Ruiz
- Escuela de Ingeniería y Ciencias, Tecnologico de Monterrey, Ave. Eugenio Garza Sada 2501, Monterrey, N.L. 64849, Mexico.
| | - Marco Rito-Palomares
- Escuela de Ingeniería y Ciencias, Tecnologico de Monterrey, Ave. Eugenio Garza Sada 2501, Monterrey, N.L. 64849, Mexico.
| | - Charles A Haynes
- Michael Smith Laboratories, University of British Columbia, Vancouver, BC, V6T 1Z4 Canada
| | - Oscar Aguilar
- Escuela de Ingeniería y Ciencias, Tecnologico de Monterrey, Ave. Eugenio Garza Sada 2501, Monterrey, N.L. 64849, Mexico.
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22
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Ma Q, Song Y, Kim JW, Choi HS, Shum HC. Affinity Partitioning-Induced Self-Assembly in Aqueous Two-Phase Systems: Templating for Polyelectrolyte Microcapsules. ACS Macro Lett 2016; 5:666-670. [PMID: 35614670 DOI: 10.1021/acsmacrolett.6b00228] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Affinity partitioning refers to the preferential dissolution of solute molecules in a particular liquid phase of an immiscible liquid-liquid mixture, such as an aqueous two-phase system (ATPS). Affinity partitioning in ATPS is widely used to achieve extraction and purification of biomolecules. However, the potential of applying it to direct the self-assembly of solutes into controlled structures has been largely overlooked. Here we introduce the affinity partitioning of polyelectrolytes in ATPS to induce their self-assembly into polyelectrolyte microcapsules. The approach is purely based on the preferential solubility of different polyelectrolytes in different aqueous phases; therefore it has wide applicability and exhibits excellent compatibility with bioactives. The release of encapsulated components can be triggered by changing the pH value or ionic strength of the surrounding environment. The proposed method represents an important advance in fabricating multifunctional materials and inspires new ways to engineer sophisticated structures with hydrophilic macromolecules.
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Affiliation(s)
- Qingming Ma
- Department
of Mechanical Engineering, University of Hong Kong, Pokfulam Road, Hong Kong, China
- HKU-Shenzhen Institute
of Research and Innovation (HKU-SIRI), Shenzhen 518000, China
| | - Yang Song
- Department
of Mechanical Engineering, University of Hong Kong, Pokfulam Road, Hong Kong, China
- HKU-Shenzhen Institute
of Research and Innovation (HKU-SIRI), Shenzhen 518000, China
| | | | - Hong Sung Choi
- Shinsegae International
Co. Ltd., Seoul, 135-954, Republic of Korea
| | - Ho Cheung Shum
- Department
of Mechanical Engineering, University of Hong Kong, Pokfulam Road, Hong Kong, China
- HKU-Shenzhen Institute
of Research and Innovation (HKU-SIRI), Shenzhen 518000, China
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23
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Moon BU, Abbasi N, Jones SG, Hwang DK, Tsai SSH. Water-in-Water Droplets by Passive Microfluidic Flow Focusing. Anal Chem 2016; 88:3982-9. [PMID: 26959358 DOI: 10.1021/acs.analchem.6b00225] [Citation(s) in RCA: 78] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
We present a simple microfluidic system that generates water-in-water, aqueous two phase system (ATPS) droplets, by passive flow focusing. ATPS droplet formation is achieved by applying weak hydrostatic pressures, with liquid-filled pipette tips as fluid columns at the inlets, to introduce low speed flows to the flow focusing junction. To control the size of the droplets, we systematically vary the interfacial tension and viscosity of the ATPS fluids and adjust the fluid column height at the fluid inlets. The size of the droplets scales with a power law of the ratio of viscous stresses in the two ATPS phases. Overall, we find a drop size coefficient of variation (CV; i.e., polydispersity) of about 10%. We also find that when drops form very close to the flow focusing junction, the drops have a CV of less than 1%. Our droplet generation method is easily scalable: we demonstrate a parallel system that generates droplets simultaneously and improves the droplet production rate by up to one order of magnitude. Finally, we show the potential application of our system for encapsulating cells in water-in-water emulsions by encapsulating microparticles and cells. To the best of our knowledge, our microfluidic technique is the first that forms low interfacial tension ATPS droplets without applying external perturbations. We anticipate that this simple approach will find utility in drug and cell delivery applications because of the all-biocompatible nature of the water-in-water ATPS environment.
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Affiliation(s)
- Byeong-Ui Moon
- Keenan Research Centre for Biomedical Science, St. Michael's Hospital , Toronto, Canada.,Institute for Biomedical Engineering, Science and Technology (iBEST), a partnership between Ryerson University and St. Michael's Hospital , Toronto, Canada
| | - Niki Abbasi
- Keenan Research Centre for Biomedical Science, St. Michael's Hospital , Toronto, Canada.,Institute for Biomedical Engineering, Science and Technology (iBEST), a partnership between Ryerson University and St. Michael's Hospital , Toronto, Canada
| | - Steven G Jones
- Keenan Research Centre for Biomedical Science, St. Michael's Hospital , Toronto, Canada.,Institute for Biomedical Engineering, Science and Technology (iBEST), a partnership between Ryerson University and St. Michael's Hospital , Toronto, Canada
| | - Dae Kun Hwang
- Keenan Research Centre for Biomedical Science, St. Michael's Hospital , Toronto, Canada.,Institute for Biomedical Engineering, Science and Technology (iBEST), a partnership between Ryerson University and St. Michael's Hospital , Toronto, Canada
| | - Scott S H Tsai
- Keenan Research Centre for Biomedical Science, St. Michael's Hospital , Toronto, Canada.,Institute for Biomedical Engineering, Science and Technology (iBEST), a partnership between Ryerson University and St. Michael's Hospital , Toronto, Canada
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24
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Breisig H, Wessling M. Droplet formation and shrinking in aqueous two-phase systems using a membrane emulsification method. BIOMICROFLUIDICS 2015; 9:044122. [PMID: 26339321 PMCID: PMC4552692 DOI: 10.1063/1.4929519] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2015] [Accepted: 08/12/2015] [Indexed: 06/05/2023]
Abstract
Using a membrane emulsification method based on porous hollow-fiber membranes in combination with an aqueous two-phase system (ATPS), we are able to produce "water-in-water" droplets with narrow-dispersed size distributions. The equilibrium phases of the aqueous two-phase system polyethylene glycol-dipotassium hydrogen phosphate are used for this purpose. The droplet diameter of a given fluid system is determined by the flow rates of the continuous and disperse phase as well as the hollow fiber dimensions. When diluting the disperse phase and thus moving the ATPS system out of equilibrium, the droplet size can be further reduced in comparison to the equilibrium case. Generally, droplets formed with this method have diameters 20%-60% larger than the inner hollow fiber diameter. The new strategy of diluting the disperse phase allows the production of droplet diameter below the inner diameter of the membrane.
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25
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Wang WT, Sang FN, Xu JH, Wang YD, Luo GS. The enhancement of liquid–liquid extraction with high phase ratio by microfluidic-based hollow droplet. RSC Adv 2015. [DOI: 10.1039/c5ra15769b] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
We developed a novel method to enhance the liquid–liquid extraction by a microfluidic-based hollow droplet structure. A one-step microfluidic device is used for the generation of gas-in-oil-in-water double emulsions.
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Affiliation(s)
- Wen-Ting Wang
- The State Key Lab of Chemical Engineering
- Department of Chemical Engineering
- Tsinghua University
- Beijing 100084
- China
| | - Fu-Ning Sang
- The State Key Lab of Chemical Engineering
- Department of Chemical Engineering
- Tsinghua University
- Beijing 100084
- China
| | - Jian-Hong Xu
- The State Key Lab of Chemical Engineering
- Department of Chemical Engineering
- Tsinghua University
- Beijing 100084
- China
| | - Yun-Dong Wang
- The State Key Lab of Chemical Engineering
- Department of Chemical Engineering
- Tsinghua University
- Beijing 100084
- China
| | - Guang-Sheng Luo
- The State Key Lab of Chemical Engineering
- Department of Chemical Engineering
- Tsinghua University
- Beijing 100084
- China
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26
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Atefi E, Mann JA, Tavana H. Ultralow interfacial tensions of aqueous two-phase systems measured using drop shape. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2014; 30:9691-9. [PMID: 25068649 DOI: 10.1021/la500930x] [Citation(s) in RCA: 88] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Aqueous solutions of different polymers can separate and form aqueous two-phase systems (ATPS). ATPS provide an aqueous, biocompatible, and mild environment for separation and fractionation of biomolecules. The interfacial tension between the two aqueous phases plays a major role in ATPS-mediated partition of biomolecules. Because of the structure of the two aqueous phases, the interfacial tensions between the phases can be 3-4 orders of magnitude smaller than conventional fluid-liquid systems: ∼1-100 μJ/m(2) for ATPS compared to ∼72 mJ/m(2) for the water-vapor interface. This poses a major challenge for the experimental measurements of reproducible interfacial tension data for these systems. We address the need for precise determination of ultralow interfacial tensions by systematically studying a series of polymeric ATPS comprising of polyethylene glycol (PEG) and dextran (DEX) as the phase-forming polymers. Sessile and pendant drops of the denser DEX phase are formed within the immersion PEG phase. An axisymmetric drop shape analysis (ADSA) is used to determine interfacial tensions of eight different ATPS. Specific criteria are used to reproducibly determine ultralow interfacial tensions of the ATPS from pendant and sessile drops. Importantly, for a given ATPS, pendant drop and sessile drop experiments return values within 0.001 mJ/m(2) indicating reliability of our measurements. Then, the pendant drop technique is used to measure interfacial tensions of all eight ATPS. Our measured values range from 0.012 ± 0.001 mJ/m(2) to 0.381 ± 0.006 mJ/m(2) and vary with the concentration of polymers in equilibrated phases of ATPS. Measurements of ultralow interfacial tensions with such reproducibility will broadly benefit studies involving partition of different biomolecules in ATPS and elucidate the critical effect of interfacial tension.
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Affiliation(s)
- Ehsan Atefi
- Department of Biomedical Engineering, The University of Akron , Akron, Ohio 44325, United States
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27
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Campos CDM, Park JK, Neužil P, da Silva JAF, Manz A. Membrane-free electroextraction using an aqueous two-phase system. RSC Adv 2014. [DOI: 10.1039/c4ra09246e] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
We present a method of continuous electroextraction of amino acids using aqueous two phase system in a microchip. The separations occur due to differences in electrophoretic mobility and solvent affinity. The results suggest the possibility of high levels of purification by controlling the electric field across the liquid barrier.
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Affiliation(s)
- C. D. M. Campos
- KIST-Europe
- 66123 Saarbrücken, Germany
- Chemistry Institute
- State University of Campinas
- Campinas, Brazil
| | | | - P. Neužil
- KIST-Europe
- 66123 Saarbrücken, Germany
| | - J. A. F. da Silva
- Chemistry Institute
- State University of Campinas
- Campinas, Brazil
- Instituto Nacional de Ciência e Tecnologia em Bioanalítica
- INCTBio
| | - A. Manz
- KIST-Europe
- 66123 Saarbrücken, Germany
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28
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Song Y, Sauret A, Cheung Shum H. All-aqueous multiphase microfluidics. BIOMICROFLUIDICS 2013; 7:61301. [PMID: 24454609 PMCID: PMC3888457 DOI: 10.1063/1.4827916] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2013] [Accepted: 10/18/2013] [Indexed: 05/05/2023]
Abstract
Immiscible aqueous phases, formed by dissolving incompatible solutes in water, have been used in green chemical synthesis, molecular extraction and mimicking of cellular cytoplasm. Recently, a microfluidic approach has been introduced to generate all-aqueous emulsions and jets based on these immiscible aqueous phases; due to their biocompatibility, these all-aqueous structures have shown great promises as templates for fabricating biomaterials. The physico-chemical nature of interfaces between two immiscible aqueous phases leads to unique interfacial properties, such as an ultra-low interfacial tension. Strategies to manipulate components and direct their assembly at these interfaces needs to be explored. In this paper, we review progress on the topic over the past few years, with a focus on the fabrication and stabilization of all-aqueous structures in a multiphase microfluidic platform. We also discuss future efforts needed from the perspectives of fluidic physics, materials engineering, and biology for fulfilling potential applications ranging from materials fabrication to biomedical engineering.
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Affiliation(s)
- Yang Song
- Department of Mechanical Engineering, the University of Hong Kong, Hong Kong ; HKU-Shenzhen Institute of Research and Innovation (HKU-SIRI), Shenzhen, Guangdong, China
| | - Alban Sauret
- Department of Mechanical and Aerospace Engineering, Princeton University, Princeton, New Jersey 08544, USA
| | - Ho Cheung Shum
- Department of Mechanical Engineering, the University of Hong Kong, Hong Kong ; HKU-Shenzhen Institute of Research and Innovation (HKU-SIRI), Shenzhen, Guangdong, China
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29
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Song Y, Liu Z, Kong T, Shum HC. Manipulation of viscous all-aqueous jets by electrical charging. Chem Commun (Camb) 2013; 49:1726-8. [PMID: 23340715 DOI: 10.1039/c3cc38094g] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
We demonstrate the manipulation of viscous all-aqueous jets by electrical charging. At sufficiently high voltages, the folding of an uncharged viscous jet is suppressed, and the jet diameter can be adjusted by varying the applied voltage or the fluid flow rates. This inspires new ways to fabricate biocompatible fibers.
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Affiliation(s)
- Yang Song
- Department of Mechanical Engineering, The University of Hong Kong, Pokfulam Road, Hong Kong
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30
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Boreyko JB, Mruetusatorn P, Retterer ST, Collier CP. Aqueous two-phase microdroplets with reversible phase transitions. LAB ON A CHIP 2013; 13:1295-301. [PMID: 23381219 DOI: 10.1039/c3lc41122b] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Aqueous two-phase systems contained within microdroplets enable a bottom-up approach to mimicking the dynamic microcompartmentation of biomaterial that naturally occurs within the cytoplasm of cells. Here, we demonstrate the generation of femtolitre aqueous two-phase droplets within a microfluidic oil channel. Gated pressure pulses were used to generate individual, stationary two-phase microdroplets with a well-defined time zero for carrying out controlled and sequential phase transformations over time. Reversible phase transitions between single-phase, two-phase, and core-shell microbead states were obtained via evaporation-induced dehydration and water rehydration. In contrast to other microfluidic aqueous two-phase droplets, which require continuous flows and high-frequency droplet formation, our system enables the controlled isolation and reversible transformation of a single microdroplet and is expected to be useful for future studies in dynamic microcompartmentation and affinity partitioning.
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Affiliation(s)
- Jonathan B Boreyko
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN 37831-6493, USA
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31
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Ríos Á, Ríos Á, Zougagh M, Zougagh M. Sample preparation for micro total analytical systems (μ-TASs). Trends Analyt Chem 2013. [DOI: 10.1016/j.trac.2012.12.009] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
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32
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Novak U, Pohar A, Plazl I, Žnidaršič-Plazl P. Ionic liquid-based aqueous two-phase extraction within a microchannel system. Sep Purif Technol 2012. [DOI: 10.1016/j.seppur.2012.01.033] [Citation(s) in RCA: 75] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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33
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Ríos Á, Zougagh M, Avila M. Miniaturization through lab-on-a-chip: Utopia or reality for routine laboratories? A review. Anal Chim Acta 2012; 740:1-11. [DOI: 10.1016/j.aca.2012.06.024] [Citation(s) in RCA: 126] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2012] [Revised: 05/31/2012] [Accepted: 06/12/2012] [Indexed: 02/09/2023]
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34
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Hui Sophia Lee S, Wang P, Kun Yap S, Alan Hatton T, Khan SA. Tunable spatial heterogeneity in structure and composition within aqueous microfluidic droplets. BIOMICROFLUIDICS 2012; 6:22005-220058. [PMID: 22655009 PMCID: PMC3360713 DOI: 10.1063/1.3694841] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/2011] [Accepted: 02/06/2012] [Indexed: 05/12/2023]
Abstract
In this paper, we demonstrate biphasic microfluidic droplets with broadly tunable internal structures, from simple near-equilibrium drop-in-drop morphologies to complex yet uniform non-equilibrium steady-state structures. The droplets contain an aqueous mixture of poly(ethylene glycol) (PEG) and dextran and are dispensed into an immiscible oil in a microfluidic T-junction device. Above a certain well-defined threshold droplet speed, the inner dextran-rich phase is "stirred" within the outer PEG-rich phase. The stirred polymer mixture is observed to exhibit a near continuum of speed and composition-dependent phase morphologies. There is increasing interest in the use of such aqueous two-phase systems in microfluidic devices for biomolecular applications in a variety of contexts. Our work presents a method to go beyond equilibrium phase morphologies in generating microfluidic "multiple" emulsions and at the same time raises the possibility of biochemical experimentation in benign yet complex biomimetic milieus.
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35
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Abstract
An overview is given about research activities in which aqueous two phase systems (ATPSs) are utilized in microfluidic setups. ATPSs consist of two immiscible aqueous phases and have traditionally been used for the separation and purification of biological material such as proteins or cells. Microfluidic implementations of such schemes are usually based on a number of co-flowing streams of immiscible phases in a microchannel, thereby replacing the standard batch by flow-through processes. Some aspects of the stability of such flow patterns and the recovery of the phases at the channel exit are reviewed. Furthermore, the diffusive mass transfer and sample partitioning between the phases are discussed, and corresponding applications are highlighted. When diffusion is superposed by an applied electric field normal to the liquid/liquid interface, the transport processes are accelerated, and under specific conditions the interface acts as a size-selective filter for molecules. Finally, the activities involving droplet microflows of ATPSs are reviewed. By either forming ATPS droplets in an organic phase or a droplet of one aqueous phase inside the other, a range of applications has been demonstrated, extending from separation/purification schemes to the patterning of surfaces covered with cells.
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Affiliation(s)
- Steffen Hardt
- Center of Smart Interfaces, TU Darmstadt, Petersenstr. 32, D-64287 Darmstadt, Germany.
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36
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Hahn T, Hardt S. Concentration and size separation of DNA samples at liquid-liquid interfaces. Anal Chem 2011; 83:5476-9. [PMID: 21682284 DOI: 10.1021/ac201228v] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
This report introduces a new analytical concept utilizing the mass transfer resistance of a liquid-liquid interface to concentrate and separate DNA samples. DNA molecules can be electrophoretically accumulated at a liquid-liquid interface of an aqueous two-phase system (ATPS) of poly(ethylene glycol) (PEG) and dextran, two polymers that form two immiscible phases in aqueous electrolyte solutions. The detachment of DNA from the interface into the other phase can be triggered by increasing the applied electric field. We experimentally study the size dependence of the detachment process for a broad spectrum of DNA fragments. In a regime where the coiling of the chains does not play a significant role, the process shows a linear dependence on the diffusion coefficient, with shorter DNA chains detaching at lower electric field strengths than larger ones. The concept may enable novel separation protocols for preparative and analytical purposes.
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37
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Clark WM, Lindblad MA. Numerical Analysis of Two-Phase Electrophoresis. SEP SCI TECHNOL 2011. [DOI: 10.1080/01496395.2011.573518] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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38
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Hahn T, Münchow G, Hardt S. Electrophoretic transport of biomolecules across liquid-liquid interfaces. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2011; 23:184107. [PMID: 21508474 DOI: 10.1088/0953-8984/23/18/184107] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
The mass transfer resistance of a liquid-liquid interface in an aqueous two-phase system composed of poly(ethylene glycol) and dextran is investigated. Different types of proteins and DNA stained with fluorescent dyes serve as probes to study the transport processes close to the interface. A microfluidic device is employed to enable the electrophoretic transport of biomolecules from one phase to another. The results obtained for proteins can be explained solely via the different electrophoretic mobilities and different affinities of the molecules to the two phases, without any indications of a significant mass transfer resistance of the liquid-liquid interface. By contrast, DNA molecules adsorb to the interface and only desorb under an increased electric field strength. The desorption process carries the signature of a thermally activated escape from a metastable state, as reflected in the exponential decay of the fluorescence intensity at the interface as a function of time.
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Affiliation(s)
- Thomas Hahn
- Center of Smart Interfaces, TU Darmstadt, Darmstadt, Germany.
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39
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Collins CJ, Strutwolf J, Arrigan DWM. Pharmaceutical modulation of diffusion potentials at aqueous-aqueous boundaries under laminar flow conditions. Electrophoresis 2011; 32:844-9. [DOI: 10.1002/elps.201000299] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2010] [Revised: 07/16/2010] [Accepted: 08/02/2010] [Indexed: 11/12/2022]
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40
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Tavana H, Takayama S. Aqueous biphasic microprinting approach to tissue engineering. BIOMICROFLUIDICS 2011; 5:13404. [PMID: 21522494 PMCID: PMC3082341 DOI: 10.1063/1.3516658] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/13/2010] [Accepted: 10/26/2010] [Indexed: 05/16/2023]
Abstract
We summarize a recently developed microtechnology for printing biomaterials on biological surfaces. The technique is based on the use of immiscible aqueous solutions of two biopolymers and allows spatially defined placement of cells and biomolecules suspended in the denser aqueous phase on existing cell layers and extracellular matrix hydrogel surfaces maintained in the second phase. Printing takes place due to an extremely small interfacial tension and density difference between the two aqueous phases. The contact-free printing process ensures that both printed cells and the underlying cell monolayer maintain full viability and functionality. The technique accommodates both arbitrarily shaped patterns and microarrays of cells and bioreagents. The capability to print cells and small molecules on existing cell layers enables unique interrogations of the effects of cell-cell and cell-material interaction on cell fate and function. Furthermore, the very gentle conditions and the ability to directly pattern nongel embedded cells over cells make this technology appealing to tissue engineering applications where patterned multicellar organization with minimal scaffolding materials is needed, such as in dense tissues of the skeletal muscle and liver.
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41
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Huh YS, Jeon SJ, Lee EZ, Park HS, Hong WH. Microfluidic extraction using two phase laminar flow for chemical and biological applications. KOREAN J CHEM ENG 2011. [DOI: 10.1007/s11814-010-0533-8] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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42
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Ziemecka I, van Steijn V, Koper GJM, Rosso M, Brizard AM, van Esch JH, Kreutzer MT. Monodisperse hydrogel microspheres by forced droplet formation in aqueous two-phase systems. LAB ON A CHIP 2011; 11:620-4. [PMID: 21125099 DOI: 10.1039/c0lc00375a] [Citation(s) in RCA: 100] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
This paper presents a method to form micron-sized droplets in an aqueous two-phase system (ATPS) and to subsequently polymerize the droplets to produce hydrogel beads. Owing to the low interfacial tension in ATPS, droplets do not easily form spontaneously. We enforce the formation of drops by perturbing an otherwise stable jet that forms at the junction where the two aqueous streams meet. This is done by actuating a piezo-electric bending disc integrated in our device. The influence of forcing amplitude and frequency on jet breakup is described and related to the size of monodisperse droplets with a diameter in the range between 30 and 60 μm. Rapid on-chip polymerization of derivatized dextran inside the droplets created monodisperse hydrogel particles. This work shows how droplet-based microfluidics can be used in all-aqueous, surfactant-free, organic-solvent-free biocompatible two-phase environment.
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Affiliation(s)
- Iwona Ziemecka
- Delft University of Technology, Department of Chemical Engineering, Delft, The Netherlands
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Hu R, Feng X, Chen P, Fu M, Chen H, Guo L, Liu BF. Rapid, highly efficient extraction and purification of membrane proteins using a microfluidic continuous-flow based aqueous two-phase system. J Chromatogr A 2011; 1218:171-7. [PMID: 21112057 DOI: 10.1016/j.chroma.2010.10.090] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2010] [Revised: 10/22/2010] [Accepted: 10/25/2010] [Indexed: 10/18/2022]
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44
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Sandison ME, Cumming SA, Kolch W, Pitt AR. On-chip immunoprecipitation for protein purification. LAB ON A CHIP 2010; 10:2805-2813. [PMID: 20714512 DOI: 10.1039/c005295g] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Immunoprecipitation (IP) is one of the most widely used and selective techniques for protein purification. Here, a miniaturised, polymer-supported immunoprecipitation (µIP) method for the on-chip purification of proteins from complex mixtures is described. A 4 µl PDMS column functionalised with covalently bound antibodies was created and all critical aspects of the µIP protocol (antibody immobilisation, blocking of potential non-specific adsorption sites, sample incubation and washing conditions) were assessed and optimised. The optimised µIP method was used to obtain purified fractions of affinity-tagged protein from a bacterial lysate.
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Affiliation(s)
- Mairi E Sandison
- Integrative and Systems Biology, FBLS, University of Glasgow, Glasgow, G12 8QQ, UK.
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Choi YH, Song YS, Kim DH. Droplet-based microextraction in the aqueous two-phase system. J Chromatogr A 2010; 1217:3723-8. [DOI: 10.1016/j.chroma.2010.04.015] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2009] [Revised: 04/03/2010] [Accepted: 04/09/2010] [Indexed: 11/29/2022]
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46
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Electric field-enhanced transport across phase boundaries and membranes and its potential use in sample pretreatment for bioanalysis. Electrophoresis 2010; 31:768-85. [DOI: 10.1002/elps.200900561] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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47
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Tornay R, Braschler T, Renaud P. Wide channel dielectrophoresis-based particle exchanger with electrophoretic diffusion compensation. LAB ON A CHIP 2009; 9:657-660. [PMID: 19224014 DOI: 10.1039/b816043k] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
We present here a microfluidic device for the chemical modification of particles. In order to alleviate diffusive mixing issues beads are pushed from a starting buffer to a reagent over a wide channel by an array of shifted electrodes. We also show that the effect of reagent diffusion can be compensated by electrophoretic forces.
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Affiliation(s)
- Raphaël Tornay
- Microsystem Laboratory, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland.
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48
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West J, Becker M, Tombrink S, Manz A. Micro Total Analysis Systems: Latest Achievements. Anal Chem 2008; 80:4403-19. [PMID: 18498178 DOI: 10.1021/ac800680j] [Citation(s) in RCA: 351] [Impact Index Per Article: 21.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- Jonathan West
- ISAS, Institute for Analytical Sciences, Bunsen-Kirchhoff-Strasse 11, D-44139 Dortmund, Germany
| | - Marco Becker
- ISAS, Institute for Analytical Sciences, Bunsen-Kirchhoff-Strasse 11, D-44139 Dortmund, Germany
| | - Sven Tombrink
- ISAS, Institute for Analytical Sciences, Bunsen-Kirchhoff-Strasse 11, D-44139 Dortmund, Germany
| | - Andreas Manz
- ISAS, Institute for Analytical Sciences, Bunsen-Kirchhoff-Strasse 11, D-44139 Dortmund, Germany
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49
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Meagher RJ, Light YK, Singh AK. Rapid, continuous purification of proteins in a microfluidic device using genetically-engineered partition tags. LAB ON A CHIP 2008; 8:527-32. [PMID: 18369506 DOI: 10.1039/b716462a] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
High-throughput screening assays of native and recombinant proteins are increasingly crucial in life science research, including fields such as drug screening and enzyme engineering. These assays are typically highly parallel, and require minute amounts of purified protein per assay. To address this need, we have developed a rapid, automated microscale process for isolating specific proteins from sub-microlitre volumes of E. Coli cell lysate. Recombinant proteins are genetically tagged to drive partitioning into the PEG-rich phase of a flowing aqueous two-phase system, which removes approximately 85% of contaminating proteins, as well as unwanted nucleic acids and cell debris, on a simple microfluidic device. Inclusion of the genetic tag roughly triples recovery of the autofluorescent protein AcGFP1, and also significantly improves recovery of the enzyme glutathione S-transferase (GST), from nearly zero recovery for the wild-type enzyme, up to 40% with genetic tagging. The extraction process operates continuously, with only a single step from cell lysate to purified protein, and does not require expensive affinity reagents or troublesome chromatographic steps. The two-phase system is mild and does not disrupt protein function, as evidenced by recovery of active enzymes and functional fluorescent protein from our microfluidic process. The microfluidic aqueous two-phase extraction forms the core component of an integrated lab-on-a-chip device comprising cell culture, lysis, purification and analysis on a single device.
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Affiliation(s)
- Robert J Meagher
- Sandia National Laboratories, Biosystems Research Department, P.O. Box 969, Livermore, CA 95391, USA
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Abstract
Biochemical sample mixtures are commonly separated in batch processes, such as filtration, centrifugation, chromatography or electrophoresis. In recent years, however, many research groups have demonstrated continuous flow separation methods in microfluidic devices. Such separation methods are characterised by continuous injection, real-time monitoring, as well as continuous collection, which makes them ideal for combination with upstream and downstream applications. Importantly, in continuous flow separation the sample components are deflected from the main direction of flow, either by means of a force field (electric, magnetic, acoustic, optical etc.), or by intelligent positioning of obstacles in combination with laminar flow profiles. Sample components susceptible to deflection can be spatially separated. A large variety of methods has been reported, some of these are miniaturised versions of larger scale methods, others are only possible in microfluidic regimes. Researchers now have a diverse toolbox to choose from and it is likely that continuous flow methods will play an important role in future point-of-care or in-the-field analysis devices.
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Affiliation(s)
- Nicole Pamme
- The University of Hull, Department of Chemistry, Cottingham Road, Hull, UK HU6 7RX.
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