1
|
De Lora JA, Aubermann F, Frey C, Jahnke T, Wang Y, Weber S, Platzman I, Spatz JP. Evaluation of Acoustophoretic and Dielectrophoretic Forces for Droplet Injection in Droplet-Based Microfluidic Devices. ACS OMEGA 2024; 9:16097-16105. [PMID: 38617618 PMCID: PMC11007716 DOI: 10.1021/acsomega.3c09881] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/11/2023] [Revised: 03/05/2024] [Accepted: 03/18/2024] [Indexed: 04/16/2024]
Abstract
Acoustophoretic forces have been successfully implemented into droplet-based microfluidic devices to manipulate droplets. These acoustophoretic forces in droplet microfluidic devices are typically generated as in acoustofluidic devices through transducer actuation of a piezoelectric substrate such as lithium niobate (LiNbO3), which is inherently accompanied by the emergence of electrical fields. Understanding acoustophoretic versus dielectrophoretic forces produced by electrodes and transducers within active microfluidic devices is important for the optimization of device performance during design iterations. In this case study, we design microfluidic devices with a droplet injection module and report an experimental strategy to deduce the respective contribution of the acoustophoretic versus dielectrophoretic forces for the observed droplet injection. Our PDMS-based devices comprise a standard oil-in-water droplet-generating module connected to a T-junction injection module featuring actuating electrodes. We use two different electrode geometries produced within the same PDMS slab as the droplet production/injection channels by filling low-melting-point metal alloy into channels that template the electrode geometries. When these electrodes are constructed on LiNbO3 as the substrate, they have a dual function as a piezoelectric transducer, which we call embedded liquid metal interdigitated transducers (elmIDTs). To decipher the contribution of acoustophoretic versus dielectrophoretic forces, we build the same devices on either piezoelectric LiNbO3 or nonpiezo active glass substrates with different combinations of physical device characteristics (i.e., elmIDT geometry and alignment) and operate in a range of phase spaces (i.e., frequency, voltage, and transducer polarity). We characterize devices using techniques such as laser Doppler vibrometry (LDV) and infrared imaging, along with evaluating droplet injection for our series of device designs, constructions, and operating parameters. Although we find that LiNbO3 device designs generate acoustic fields, we demonstrate that droplet injection occurs only due to dielectrophoretic forces. We deduce that droplet injection is caused by the coupled dielectrophoretic forces arising from the operation of elmIDTs rather than by acoustophoretic forces for this specific device design. We arrive at this conclusion because equivalent droplet injection occurs without the presence of an acoustic field using the same electrode designs on nonpiezo active glass substrate devices. This work establishes a methodology to pinpoint the major contributing force of droplet manipulation in droplet-based acoustomicrofluidics.
Collapse
Affiliation(s)
- Jacqueline A. De Lora
- Department
of Cellular Biophysics, Max Planck Institute
for Medical Research, Jahnstraße 29, 69120 Heidelberg, Germany
- Institute
for Molecular Systems Engineering (IMSE), Heidelberg University, Im Neuenheimer Feld 225, 69120 Heidelberg, Germany
| | - Florian Aubermann
- Department
of Cellular Biophysics, Max Planck Institute
for Medical Research, Jahnstraße 29, 69120 Heidelberg, Germany
- Institute
for Molecular Systems Engineering (IMSE), Heidelberg University, Im Neuenheimer Feld 225, 69120 Heidelberg, Germany
- Max
Planck School Matter to Life, Jahnstraße 29, 69120 Heidelberg, Germany
| | - Christoph Frey
- Department
of Cellular Biophysics, Max Planck Institute
for Medical Research, Jahnstraße 29, 69120 Heidelberg, Germany
- Institute
for Molecular Systems Engineering (IMSE), Heidelberg University, Im Neuenheimer Feld 225, 69120 Heidelberg, Germany
| | - Timotheus Jahnke
- Department
of Cellular Biophysics, Max Planck Institute
for Medical Research, Jahnstraße 29, 69120 Heidelberg, Germany
- Institute
for Molecular Systems Engineering (IMSE), Heidelberg University, Im Neuenheimer Feld 225, 69120 Heidelberg, Germany
| | - Yuanzhen Wang
- Department
of Cellular Biophysics, Max Planck Institute
for Medical Research, Jahnstraße 29, 69120 Heidelberg, Germany
- Institute
for Molecular Systems Engineering (IMSE), Heidelberg University, Im Neuenheimer Feld 225, 69120 Heidelberg, Germany
| | - Sebastian Weber
- Department
of Cellular Biophysics, Max Planck Institute
for Medical Research, Jahnstraße 29, 69120 Heidelberg, Germany
- Institute
for Molecular Systems Engineering (IMSE), Heidelberg University, Im Neuenheimer Feld 225, 69120 Heidelberg, Germany
| | - Ilia Platzman
- Department
of Cellular Biophysics, Max Planck Institute
for Medical Research, Jahnstraße 29, 69120 Heidelberg, Germany
- Institute
for Molecular Systems Engineering (IMSE), Heidelberg University, Im Neuenheimer Feld 225, 69120 Heidelberg, Germany
| | - Joachim P. Spatz
- Department
of Cellular Biophysics, Max Planck Institute
for Medical Research, Jahnstraße 29, 69120 Heidelberg, Germany
- Institute
for Molecular Systems Engineering (IMSE), Heidelberg University, Im Neuenheimer Feld 225, 69120 Heidelberg, Germany
- Max
Planck School Matter to Life, Jahnstraße 29, 69120 Heidelberg, Germany
| |
Collapse
|
2
|
Shukla M, Malik S, Pandya A. Lab on chip for testing of repurposed drugs. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2024; 205:71-90. [PMID: 38789187 DOI: 10.1016/bs.pmbts.2024.03.022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2024]
Abstract
The lab-on-chip technique broadly comprises of microfluidics and aims to progress multidimensionally by changing the outlook of medicine and pharmaceuticals as it finds it roots in miniaturization. Moreover, microfluidics facilitates precise physiological simulation and possesses biological system-mimicking capabilities for drug development and repurposing. Thus, organs on chip could pave a revolutionary pathway in the field of drug development and repurposing by reducing animal testing and improving drug repurposing.
Collapse
Affiliation(s)
- Malvika Shukla
- Department of Biotechnology and Bioengineering, Institute of Advanced Research, Gandhinagar, Gujarat, India
| | - Saloni Malik
- Department of Biotechnology and Bioengineering, Institute of Advanced Research, Gandhinagar, Gujarat, India
| | - Alok Pandya
- Department of Biotechnology and Bioengineering, Institute of Advanced Research, Gandhinagar, Gujarat, India; Department of Nanoengineering, University of California San Diego, La Jolla, CA, United States.
| |
Collapse
|
3
|
Waeterschoot J, Gosselé W, Alizadeh Zeinabad H, Lammertyn J, Koos E, Casadevall I Solvas X. Formation of Giant Unilamellar Vesicles Assisted by Fluorinated Nanoparticles. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2023; 10:e2302461. [PMID: 37807811 DOI: 10.1002/advs.202302461] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/18/2023] [Revised: 07/31/2023] [Indexed: 10/10/2023]
Abstract
In the quest to produce artificial cells, one key challenge that remains to be solved is the recreation of a complex cellular membrane. Among the existing models, giant unilamellar vesicles (GUVs) are particularly interesting due to their intrinsic compartmentalisation ability and their resemblance in size and shape to eukaryotic cells. Many techniques have been developed to produce GUVs all having inherent advantages and disadvantages. Here, the authors show that fluorinated silica nanoparticles (FNPs) used to form Pickering emulsions in a fluorinated oil can destabilise lipid nanosystems to template the formation of GUVs. This technique enables GUV production across a broad spectrum of buffer conditions, while preventing the leakage of the encapsulated components into the oil phase. Furthermore, a simple centrifugation process is sufficient for the release of the emulsion-trapped GUVs, bypassing the need to use emulsion-destabilising chemicals. With fluorescent FNPs and transmission electron microscopy, the authors confirm that FNPs are efficiently removed, producing contaminant-free GUVs. Further experiments assessing the lateral diffusion of lipids and unilamellarity of the GUVs demonstrate that they are comparable to GUVs produced via electroformation. Finally, the ability of incorporating transmembrane proteins is demonstrated, highlighting the potential of this method for the production of GUVs for artificial cell applications.
Collapse
Affiliation(s)
- Jorik Waeterschoot
- Mechatronics, Biostatistics and Sensors (MeBioS) at KU Leuven, Willem de Croylaan 42, 3001, Leuven, Belgium
| | - Willemien Gosselé
- Mechatronics, Biostatistics and Sensors (MeBioS) at KU Leuven, Willem de Croylaan 42, 3001, Leuven, Belgium
| | - Hojjat Alizadeh Zeinabad
- Mechatronics, Biostatistics and Sensors (MeBioS) at KU Leuven, Willem de Croylaan 42, 3001, Leuven, Belgium
| | - Jeroen Lammertyn
- Mechatronics, Biostatistics and Sensors (MeBioS) at KU Leuven, Willem de Croylaan 42, 3001, Leuven, Belgium
| | - Erin Koos
- Soft Matter, Rheology and Technology (SMaRT) at KU Leuven, Celestijnenlaan 200J, 3000, Leuven, Belgium
| | - Xavier Casadevall I Solvas
- Mechatronics, Biostatistics and Sensors (MeBioS) at KU Leuven, Willem de Croylaan 42, 3001, Leuven, Belgium
| |
Collapse
|
4
|
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.
Collapse
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
| |
Collapse
|
5
|
Cao J, Chande C, Köhler JM. Microtoxicology by microfluidic instrumentation: a review. LAB ON A CHIP 2022; 22:2600-2623. [PMID: 35678285 DOI: 10.1039/d2lc00268j] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Microtoxicology is concerned with the toxic effects of small amounts of substances. This review paper discusses the application of small amounts of noxious substances for toxicological investigation in small volumes. The vigorous development of miniaturized methods in microfluidics over the last two decades involves chip-based devices, micro droplet-based procedures, and the use of micro-segmented flow for microtoxicological studies. The studies have shown that the microfluidic approach is particularly valuable for highly parallelized and combinatorial dose-response screenings. Accurate dosing and mixing of effector substances in large numbers of microcompartments supplies detailed data of dose-response functions by highly concentration-resolved assays and allows evaluation of stochastic responses in case of small separated cell ensembles and single cell experiments. The investigations demonstrate that very different biological targets can be studied using miniaturized approaches, among them bacteria, eukaryotic microorganisms, cell cultures from tissues of multicellular organisms, stem cells, and early embryonic states. Cultivation and effector exposure tests can be performed in small volumes over weeks and months, confirming that the microfluicial strategy is also applicable for slow-growing organisms. Here, the state of the art of miniaturized toxicology, particularly for studying antibiotic susceptibility, drug toxicity testing in the miniaturized system like organ-on-chip, environmental toxicology, and the characterization of combinatorial effects by two and multi-dimensional screenings, is discussed. Additionally, this review points out the practical limitations of the microtoxicology platform and discusses perspectives on future opportunities and challenges.
Collapse
Affiliation(s)
- Jialan Cao
- Techn. Univ. Ilmenau, Dept. Phys. Chem. and Microreaction Technology, Institute for Micro- und Nanotechnologies/Institute for Chemistry and Biotechnology, Ilmenau, Germany.
| | - Charmi Chande
- Department of Chemical and Materials Engineering, New Jersey Institute of Technology, Newark, New Jersey 07102, USA
| | - J Michael Köhler
- Techn. Univ. Ilmenau, Dept. Phys. Chem. and Microreaction Technology, Institute for Micro- und Nanotechnologies/Institute for Chemistry and Biotechnology, Ilmenau, Germany.
| |
Collapse
|
6
|
Interfacing microfluidics with information-rich detection systems for cells, bioparticles, and molecules. Anal Bioanal Chem 2022; 414:4575-4589. [PMID: 35389095 PMCID: PMC8987515 DOI: 10.1007/s00216-022-04043-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2022] [Revised: 03/01/2022] [Accepted: 03/24/2022] [Indexed: 11/16/2022]
Abstract
The development of elegant and numerous microfluidic manipulations has enabled significant advances in the processing of small volume samples and the detection of minute amounts of biomaterials. Effective isolation of single cells in a defined volume as well as manipulations of complex bioparticle or biomolecule mixtures allows for the utilization of information-rich detection methods including mass spectrometry, electron microscopy imaging, and amplification/sequencing. The art and science of translating biosamples from microfluidic platforms to highly advanced, information-rich detection system is the focus of this review, where we term the translation between the microfluidics elements to the external world “off-chipping.” When presented with the challenge of presenting sub-nanoliter volumes of manipulated sample to a detection scheme, several delivery techniques have been developed for effective analysis. These techniques include spraying (electrospray, nano-electrospray, pneumatic), meniscus-defined volumes (droplets, plugs), constrained volumes (narrow channels, containers), and phase changes (deposition, freezing). Each technique has been proven effective in delivering highly defined samples from microfluidic systems to the detection elements. This review organizes and presents selective publications that illustrate the advancements of these delivery techniques with respect to the type of sample analyzed, while introducing each strategy and providing historical perspective. The publications highlighted in this review were chosen due to their significance and relevance in the development of their respective off-chip technique.
Collapse
|
7
|
Li C, Gong Y, Wang X, Xu J, Ma B. Integrated Addressable Dynamic Droplet Array (aDDA) as Sub-Nanoliter Reactors for High-Coverage Genome Sequencing of Single Yeast Cells. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2021; 17:e2100325. [PMID: 34296526 DOI: 10.1002/smll.202100325] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/18/2021] [Revised: 06/25/2021] [Indexed: 06/13/2023]
Abstract
An addressable dynamic droplet array (aDDA) is presented that combines the advantages of static droplet arrays and continuous-flow droplet platforms. Modular fabrication is employed to create a self-contained integrated aDDA. All the sample preparation steps, including single-cell isolation, cell lysis, amplification, and product retrieval, are performed in sequence within a sub-nanoliter (≈300 pL) droplet. Sequencing-based validation suggests that aDDA reduces the amplification bias of multiple displacement amplification (MDA) and elevates the percentage of one-yeast-cell genome recovery to 91%, as compared to the average of 26% using conventional, 20 µL volume MDA reactions. Thus, aDDA is a valuable addition to the toolbox for high-genome-coverage sequencing of single microbial cells.
Collapse
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, 266071, China
| | - Yanhai Gong
- 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, 266071, China
| | - Xixian Wang
- 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, 266071, China
| | - Jian Xu
- 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, 266071, China
| | - Bo Ma
- 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, 266071, China
| |
Collapse
|
8
|
Sudeepthi A, Nath A, Yeo LY, Sen AK. Coalescence of Droplets in a Microwell Driven by Surface Acoustic Waves. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2021; 37:1578-1587. [PMID: 33478219 DOI: 10.1021/acs.langmuir.0c03292] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Microwell arrays are amongst the most commonly used platforms for biochemical assays. However, the coalescence of droplets that constitute the dispersed phase of suspensions housed within microwells has not received much attention to date. Herein, we study the coalescence of droplets in a two-phase system in a microwell driven by surface acoustic waves (SAWs). The microwell structure, together with symmetric exposure to SAW irradiation, coupled from beneath the microwell via a piezoelectric substrate, gives rise to the formation of a pair of counter-rotating vortices that enable droplet transport, trapping, and coalescence. We elucidate the physics of the coalescence phenomenon using a scaling analysis of the relevant forces, namely, the acoustic streaming-induced drag force, the capillary and viscous forces associated with the drainage of the thin continuous phase film between the droplets and the van der Waals attraction force. We confirm that droplet-droplet interface contact is established through the formation of a liquid bridge, whose neck radius grows linearly in time in the preceding viscous regime and proportionally with the square root of time in the subsequent inertial regime. Further, we investigate the influence of the input SAW power and droplet size on the film drainage time and demarcate the coalescence and non-coalescence regimes to derive a criterion for the onset of coalescence. The distinct deformation patterns observed for a pair of contacting droplets in both the regimes are elucidated and the possibility for driving concurrent coalescence of multiple droplets is demonstrated. We expect the study will find relevance in the demulsification of immiscible phases and the mixing of samples/reagents within microwells for a variety of biochemical applications.
Collapse
Affiliation(s)
- A Sudeepthi
- Micro Nano Bio -Fluidics Unit, Fluid Systems Laboratory, Department of Mechanical Engineering, Indian Institute of Technology Madras, Chennai 600036, India
| | - A Nath
- Micro Nano Bio -Fluidics Unit, Fluid Systems Laboratory, Department of Mechanical Engineering, Indian Institute of Technology Madras, Chennai 600036, India
| | - L Y Yeo
- Micro/Nanophysics Research Laboratory, School of Engineering, Royal Melbourne Institute of Technology (RMIT University), Melbourne, Victoria 3001, Australia
| | - A K Sen
- Micro Nano Bio -Fluidics Unit, Fluid Systems Laboratory, Department of Mechanical Engineering, Indian Institute of Technology Madras, Chennai 600036, India
| |
Collapse
|
9
|
Gaikwad R, Sen AK. An optomicrofluidic device for the detection and isolation of drop-encapsulated target cells in single-cell format. Analyst 2021; 146:95-108. [PMID: 33107500 DOI: 10.1039/d0an00160k] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Single-cell analysis has emerged as a powerful method for genomics, transcriptomics, proteomics, and metabolomics characterisation at the individual cell level. Here, we demonstrate a technique for the detection and selective isolation of target cells encapsulated in microdroplets in single-cell format. A sample containing a mixed population of cells with fluorescently labelled target cells can be focused using a sheath fluid to direct cells in single file toward a droplet junction, wherein the cells are encapsulated inside droplets. The droplets containing the cells migrate toward the centre of the channel owing to non-inertial lift force. The cells present in the droplets are studied and characterised based on forward scatter (FSC), side scatter (SSC), and fluorescence (FL) signals. The FL signals from the target cells can be used to activate a selective isolation module based on electro-coalescence, using suitable electronics and a program to sort droplets containing the target cells in single-cell format from droplets containing background cells. We demonstrated the detection and isolation of target cells (cancer cells: HeLa and DU145) from mixed populations of cells, peripheral blood mononuclear cells (PBMC) + cervical cancer cells (HeLa) and PBMC + human prostate cancer cells (DU145), at a concentration range of 104-106 ml-1 at 300 cells per s. The performance of the device is characterised in terms of sorting efficiency (>97%), enrichment (>1800×), purity (>98%), and recovery (>95%). The sorted target cells were found to be viable (>95% viability) and showed good proliferation when cultured, showing the potential of the proposed sorting technique for downstream analysis.
Collapse
Affiliation(s)
- R Gaikwad
- Department of Mechanical Engineering, Indian Institute of Technology Madras, Chennai-600036, India.
| | | |
Collapse
|
10
|
Jiang T, Jia Y, Sun H, Deng X, Tang D, Ren Y. Dielectrophoresis Response of Water-in-Oil-in-Water Double Emulsion Droplets with Singular or Dual Cores. MICROMACHINES 2020; 11:mi11121121. [PMID: 33348930 PMCID: PMC7766960 DOI: 10.3390/mi11121121] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/26/2020] [Revised: 12/09/2020] [Accepted: 12/09/2020] [Indexed: 11/16/2022]
Abstract
Microfluidic technologies have enabled generation of exquisite multiple emulsion droplets, which have been used in many fields, including single-cell assays, micro-sized chemical reactions, and material syntheses. Electrical controlling is an important technique for droplet manipulation in microfluidic systems, but the dielectrophoretic behaviors of multiple emulsion droplets in electrical fields are rarely studied. Here, we report on the dielectrophoresis response of double emulsion droplets in AC electric fields in microfluidic channel. A core-shell model is utilized for analyzing the polarization of droplet interfaces and the overall dielectrophoresis (DEP) force. The water-in-oil-in-water droplets, generated by glass capillary devices, experience negative DEP at low field frequency. At high frequency, however, the polarity of DEP is tunable by adjusting droplet shell thickness or core conductivity. Then, the behavior of droplets with two inner cores is investigated, where the droplets undergo rotation before being repelled or attracted by the strong field area. This work should benefit a wide range of applications that require manipulation of double emulsion droplets by electric fields.
Collapse
Affiliation(s)
- Tianyi Jiang
- School of Mechatronics Engineering, Harbin Institute of Technology, Harbin 150001, Heilongjiang, China; (T.J.); (Y.J.); (H.S.); (X.D.); (D.T.)
| | - Yankai Jia
- School of Mechatronics Engineering, Harbin Institute of Technology, Harbin 150001, Heilongjiang, China; (T.J.); (Y.J.); (H.S.); (X.D.); (D.T.)
| | - Haizhen Sun
- School of Mechatronics Engineering, Harbin Institute of Technology, Harbin 150001, Heilongjiang, China; (T.J.); (Y.J.); (H.S.); (X.D.); (D.T.)
| | - Xiaokang Deng
- School of Mechatronics Engineering, Harbin Institute of Technology, Harbin 150001, Heilongjiang, China; (T.J.); (Y.J.); (H.S.); (X.D.); (D.T.)
| | - Dewei Tang
- School of Mechatronics Engineering, Harbin Institute of Technology, Harbin 150001, Heilongjiang, China; (T.J.); (Y.J.); (H.S.); (X.D.); (D.T.)
| | - Yukun Ren
- School of Mechatronics Engineering, Harbin Institute of Technology, Harbin 150001, Heilongjiang, China; (T.J.); (Y.J.); (H.S.); (X.D.); (D.T.)
- State Key Laboratory of Robotics and System, Harbin Institute of Technology, West Da-Zhi Street 92, Harbin 150001, Heilongjiang, China
- Correspondence: ; Tel.: +86-0451-86418028; Fax: +86-0451-86402658
| |
Collapse
|
11
|
Peretzki AJ, Schmidt S, Flachowsky E, Das A, Gerhardt RF, Belder D. How electrospray potentials can disrupt droplet microfluidics and how to prevent this. LAB ON A CHIP 2020; 20:4456-4465. [PMID: 33103684 DOI: 10.1039/d0lc00936a] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
A pressure-resistant microfluidic glass chip that integrates a packed-bed HPLC column, a droplet generator and a monolithic electrospray emitter is presented. This approach enables a seamless coupling of chip-HPLC and droplet microfluidics with ESI-MS detection. For the electrical contacting of the emitter, an electrode was integrated into the channel, which reaches up to the emitter tip. The incidental finding that under certain circumstances, the electrospray potential can strongly disturb the droplet microfluidics by electrowetting, was investigated in detail. Strategies to avoid this are evaluated and include electrical shielding and/or chip layouts, where the droplet generator is positioned at a long distance from the emitter.
Collapse
Affiliation(s)
- Andrea J Peretzki
- Institute of Analytical Chemistry, Leipzig University, Johannisallee 29, D-04103 Leipzig, Germany.
| | | | | | | | | | | |
Collapse
|
12
|
Rivello F, Matuła K, Piruska A, Smits M, Mehra N, Huck WTS. Probing single-cell metabolism reveals prognostic value of highly metabolically active circulating stromal cells in prostate cancer. SCIENCE ADVANCES 2020; 6:6/40/eaaz3849. [PMID: 32998889 PMCID: PMC7527228 DOI: 10.1126/sciadv.aaz3849] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2019] [Accepted: 08/06/2020] [Indexed: 05/05/2023]
Abstract
Despite their important role in metastatic disease, no general method to detect circulating stromal cells (CStCs) exists. Here, we present the Metabolic Assay-Chip (MA-Chip) as a label-free, droplet-based microfluidic approach allowing single-cell extracellular pH measurement for the detection and isolation of highly metabolically active cells (hm-cells) from the tumor microenvironment. Single-cell mRNA-sequencing analysis of the hm-cells from metastatic prostate cancer patients revealed that approximately 10% were canonical EpCAM+ hm-CTCs, 3% were EpCAM- hm-CTCs with up-regulation of prostate-related genes, and 87% were hm-CStCs with profiles characteristic for cancer-associated fibroblasts, mesenchymal stem cells, and endothelial cells. Kaplan-Meier analysis shows that metastatic prostate cancer patients with more than five hm-cells have a significantly poorer survival probability than those with zero to five hm-cells. Thus, prevalence of hm-cells is a prognosticator of poor outcome in prostate cancer, and a potentially predictive and therapy response biomarker for agents cotargeting stromal components and preventing epithelial-to-mesenchymal transition.
Collapse
Affiliation(s)
- Francesca Rivello
- Institute for Molecules and Materials, Radboud University, Heyendaalseweg 135, 6525 AJ Nijmegen, the Netherlands
| | - Kinga Matuła
- Institute for Molecules and Materials, Radboud University, Heyendaalseweg 135, 6525 AJ Nijmegen, the Netherlands
| | - Aigars Piruska
- Institute for Molecules and Materials, Radboud University, Heyendaalseweg 135, 6525 AJ Nijmegen, the Netherlands
| | - Minke Smits
- Department of Medical Oncology, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Niven Mehra
- Department of Medical Oncology, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Wilhelm T S Huck
- Institute for Molecules and Materials, Radboud University, Heyendaalseweg 135, 6525 AJ Nijmegen, the Netherlands.
| |
Collapse
|
13
|
Kempa EE, Smith CA, Li X, Bellina B, Richardson K, Pringle S, Galman JL, Turner NJ, Barran PE. Coupling Droplet Microfluidics with Mass Spectrometry for Ultrahigh-Throughput Analysis of Complex Mixtures up to and above 30 Hz. Anal Chem 2020; 92:12605-12612. [PMID: 32786490 PMCID: PMC8009470 DOI: 10.1021/acs.analchem.0c02632] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
![]()
High-
and ultrahigh-throughput label-free sample analysis is required
by many applications, extending from environmental monitoring to drug
discovery and industrial biotechnology. HTS methods predominantly
are based on a targeted workflow, which can limit their scope. Mass
spectrometry readily provides chemical identity and abundance for
complex mixtures, and here, we use microdroplet generation microfluidics
to supply picoliter aliquots for analysis at rates up to and including
33 Hz. This is demonstrated for small molecules, peptides, and proteins
up to 66 kDa on three commercially available mass spectrometers from
salty solutions to mimic cellular environments. Designs for chip-based
interfaces that permit this coupling are presented, and the merits
and challenges of these interfaces are discussed. On an Orbitrap platform
droplet infusion rates of 6 Hz are used for analysis of cytochrome c, on a DTIMS Q-TOF similar rates were obtained, and on
a TWIMS Q-TOF utilizing IM-MS software rates up to 33 Hz are demonstrated.
The potential of this approach is demonstrated with proof of concept
experiments on crude mixtures including egg white, unpurified recombinant
protein, and a biotransformation supernatant.
Collapse
Affiliation(s)
- Emily E Kempa
- Michael Barber Centre for Collaborative Mass Spectrometry, Manchester Institute of Biotechnology, Manchester M1 7DN, United Kingdom
| | - Clive A Smith
- Sphere Fluidics Limited, McClintock Building, Suite 7, Granta Park, Great Abington, Cambridge CB21 6GP, United Kingdom
| | - Xin Li
- Sphere Fluidics Limited, McClintock Building, Suite 7, Granta Park, Great Abington, Cambridge CB21 6GP, United Kingdom
| | - Bruno Bellina
- Michael Barber Centre for Collaborative Mass Spectrometry, Manchester Institute of Biotechnology, Manchester M1 7DN, United Kingdom
| | - Keith Richardson
- Waters Corporation, Stamford Avenue, Altrincham Road, Wilmslow SK9 4AX, United Kingdom
| | - Steven Pringle
- Waters Corporation, Stamford Avenue, Altrincham Road, Wilmslow SK9 4AX, United Kingdom
| | - James L Galman
- Manchester Institute of Biotechnology, Manchester M1 7DN, United Kingdom
| | - Nicholas J Turner
- Manchester Institute of Biotechnology, Manchester M1 7DN, United Kingdom
| | - Perdita E Barran
- Michael Barber Centre for Collaborative Mass Spectrometry, Manchester Institute of Biotechnology, Manchester M1 7DN, United Kingdom
| |
Collapse
|
14
|
Yu H, Zhao W, Ren L, Wang H, Guo P, Yang X, Ye Q, Shchukin D, Du Y, Dou S, Wang H. Laser-Generated Supranano Liquid Metal as Efficient Electron Mediator in Hybrid Perovskite Solar Cells. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2020; 32:e2001571. [PMID: 32643839 DOI: 10.1002/adma.202001571] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Revised: 06/11/2020] [Indexed: 06/11/2023]
Abstract
Creating colloids of liquid metal with tailored dimensions has been of technical significance in nano-electronics while a challenge remains for generating supranano (<10 nm) liquid metal to unravel the mystery of their unconventional functionalities. Present study pioneers the technology of pulsed laser irradiation in liquid from a solid target to liquid, and yields liquid ternary nano-alloys that are laborious to obtain via wet-chemistry synthesis. Herein, the significant role of the supranano liquid metal on mediating the electrons at the grain boundaries of perovskite films, which are of significance to influence the carriers recombination and hysteresis in perovskite solar cells, is revealed. Such embedding of supranano liquid metal in perovskite films leads to a cesium-based ternary perovskite solar cell with stabilized power output of 21.32% at maximum power point tracing. This study can pave a new way of synthesizing multinary supranano alloys for advanced optoelectronic applications.
Collapse
Affiliation(s)
- Huiwu Yu
- State Key Laboratory of Solidification Processing Center for Nano Energy Materials, School of Materials Science and Engineering, Northwestern Polytechnical University and Shaanxi Joint Laboratory of Graphene (NPU), Xi'an, 710072, P. R. China
- School of Physics, Northwest University, Xi'an, 710127, P. R. China
| | - Wenhao Zhao
- State Key Laboratory of Solidification Processing Center for Nano Energy Materials, School of Materials Science and Engineering, Northwestern Polytechnical University and Shaanxi Joint Laboratory of Graphene (NPU), Xi'an, 710072, P. R. China
| | - Long Ren
- Institute for Superconducting and Electronic Materials, University of Wollongong, Wollongong, NSW, 2500, Australia
| | - Hongyue Wang
- State Key Laboratory of Solidification Processing Center for Nano Energy Materials, School of Materials Science and Engineering, Northwestern Polytechnical University and Shaanxi Joint Laboratory of Graphene (NPU), Xi'an, 710072, P. R. China
| | - Pengfei Guo
- State Key Laboratory of Solidification Processing Center for Nano Energy Materials, School of Materials Science and Engineering, Northwestern Polytechnical University and Shaanxi Joint Laboratory of Graphene (NPU), Xi'an, 710072, P. R. China
| | - Xiaokun Yang
- State Key Laboratory of Solidification Processing Center for Nano Energy Materials, School of Materials Science and Engineering, Northwestern Polytechnical University and Shaanxi Joint Laboratory of Graphene (NPU), Xi'an, 710072, P. R. China
| | - Qian Ye
- State Key Laboratory of Solidification Processing Center for Nano Energy Materials, School of Materials Science and Engineering, Northwestern Polytechnical University and Shaanxi Joint Laboratory of Graphene (NPU), Xi'an, 710072, P. R. China
| | - Dmitry Shchukin
- Stephenson Institute for Renewable Energy, University of Liverpool, Liverpool, L69 7ZF, UK
- Department of Physical and Colloid Chemistry, Gubkin University, 65/1 Leninsky Prospect, Moscow, 19991, Russia
| | - Yi Du
- Institute for Superconducting and Electronic Materials, University of Wollongong, Wollongong, NSW, 2500, Australia
- BUAA-UOW Joint Research Centre and School of Physics, Beihang University, Beijing, 100191, P. R. China
| | - Shixue Dou
- Institute for Superconducting and Electronic Materials, University of Wollongong, Wollongong, NSW, 2500, Australia
- BUAA-UOW Joint Research Centre and School of Physics, Beihang University, Beijing, 100191, P. R. China
| | - Hongqiang Wang
- State Key Laboratory of Solidification Processing Center for Nano Energy Materials, School of Materials Science and Engineering, Northwestern Polytechnical University and Shaanxi Joint Laboratory of Graphene (NPU), Xi'an, 710072, P. R. China
| |
Collapse
|
15
|
Hochstetter A. Lab-on-a-Chip Technologies for the Single Cell Level: Separation, Analysis, and Diagnostics. MICROMACHINES 2020; 11:E468. [PMID: 32365567 PMCID: PMC7281269 DOI: 10.3390/mi11050468] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/08/2020] [Revised: 04/25/2020] [Accepted: 04/25/2020] [Indexed: 12/14/2022]
Abstract
In the last three decades, microfluidics and its applications have been on an exponential rise, including approaches to isolate rare cells and diagnose diseases on the single-cell level. The techniques mentioned herein have already had significant impacts in our lives, from in-the-field diagnosis of disease and parasitic infections, through home fertility tests, to uncovering the interactions between SARS-CoV-2 and their host cells. This review gives an overview of the field in general and the most notable developments of the last five years, in three parts: 1. What can we detect? 2. Which detection technologies are used in which setting? 3. How do these techniques work? Finally, this review discusses potentials, shortfalls, and an outlook on future developments, especially in respect to the funding landscape and the field-application of these chips.
Collapse
Affiliation(s)
- Axel Hochstetter
- Experimentalphysik, Universität des Saarlandes, D-66123 Saarbrücken, Germany
| |
Collapse
|
16
|
Frey C, Göpfrich K, Pashapour S, Platzman I, Spatz JP. Electrocoalescence of Water-in-Oil Droplets with a Continuous Aqueous Phase: Implementation of Controlled Content Release. ACS OMEGA 2020; 5:7529-7536. [PMID: 32280896 PMCID: PMC7144163 DOI: 10.1021/acsomega.0c00344] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/24/2020] [Accepted: 03/11/2020] [Indexed: 06/11/2023]
Abstract
Droplet-based microfluidics have emerged as an important tool for diverse biomedical and biological applications including, but not limited to, drug screening, cellular analysis, and bottom-up synthetic biology. Each microfluidic water-in-oil droplet contains a well-defined biocontent that, following its manipulation/maturation, has to be released into a physiological environment toward possible end-user investigations. Despite the progress made in recent years, considerable challenges still loom at achieving a precise control over the content release with sufficient speed and sensitivity. Here, we present a quantitative study in which we compare the effectiveness and biocompatibility of chemical and physical microfluidic release methods. We show the advantages of electrocoalescence of water-in-oil droplets in terms of high-throughput release applications. Moreover, we apply programmable DNA nanotechnology to achieve a segregation of the biochemical content within the droplets for the controlled filtration of the encapsulated materials. We envision that the developed bifunctional microfluidic approach, capable of content segregation and selective release, will expand the microfluidic toolbox for cell biology, synthetic biology, and biomedical applications.
Collapse
Affiliation(s)
- Christoph Frey
- Department
of Cellular Biophysics, Max Planck Institute
for Medical Research, Jahnstraße 29, 69120 Heidelberg, Germany
- Department
of Biophysical Chemistry, University of
Heidelberg, Im Neuenheimer
Feld 253, 69120 Heidelberg, Germany
| | - Kerstin Göpfrich
- Department
of Cellular Biophysics, Max Planck Institute
for Medical Research, Jahnstraße 29, 69120 Heidelberg, Germany
- Department
of Biophysical Chemistry, University of
Heidelberg, Im Neuenheimer
Feld 253, 69120 Heidelberg, Germany
- Biophysical
Engineering of Life Group, Max Planck Institute
for Medical Research, Jahnstraße 29, 69120 Heidelberg, Germany
| | - Sadaf Pashapour
- Department
of Cellular Biophysics, Max Planck Institute
for Medical Research, Jahnstraße 29, 69120 Heidelberg, Germany
- Department
of Biophysical Chemistry, University of
Heidelberg, Im Neuenheimer
Feld 253, 69120 Heidelberg, Germany
| | - Ilia Platzman
- Department
of Cellular Biophysics, Max Planck Institute
for Medical Research, Jahnstraße 29, 69120 Heidelberg, Germany
- Department
of Biophysical Chemistry, University of
Heidelberg, Im Neuenheimer
Feld 253, 69120 Heidelberg, Germany
| | - Joachim P. Spatz
- Department
of Cellular Biophysics, Max Planck Institute
for Medical Research, Jahnstraße 29, 69120 Heidelberg, Germany
- Department
of Biophysical Chemistry, University of
Heidelberg, Im Neuenheimer
Feld 253, 69120 Heidelberg, Germany
- Max
Planck School Matter to Life, Jahnstraße 29, 69120 Heidelberg, Germany
| |
Collapse
|
17
|
Markel U, Essani KD, Besirlioglu V, Schiffels J, Streit WR, Schwaneberg U. Advances in ultrahigh-throughput screening for directed enzyme evolution. Chem Soc Rev 2020; 49:233-262. [PMID: 31815263 DOI: 10.1039/c8cs00981c] [Citation(s) in RCA: 142] [Impact Index Per Article: 35.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Enzymes are versatile catalysts and their synthetic potential has been recognized for a long time. In order to exploit their full potential, enzymes often need to be re-engineered or optimized for a given application. (Semi-) rational design has emerged as a powerful means to engineer proteins, but requires detailed knowledge about structure function relationships. In turn, directed evolution methodologies, which consist of iterative rounds of diversity generation and screening, can improve an enzyme's properties with virtually no structural knowledge. Current diversity generation methods grant us access to a vast sequence space (libraries of >1012 enzyme variants) that may hide yet unexplored catalytic activities and selectivity. However, the time investment for conventional agar plate or microtiter plate-based screening assays represents a major bottleneck in directed evolution and limits the improvements that are obtainable in reasonable time. Ultrahigh-throughput screening (uHTS) methods dramatically increase the number of screening events per time, which is crucial to speed up biocatalyst design, and to widen our knowledge about sequence function relationships. In this review, we summarize recent advances in uHTS for directed enzyme evolution. We shed light on the importance of compartmentalization to preserve the essential link between genotype and phenotype and discuss how cells and biomimetic compartments can be applied to serve this function. Finally, we discuss how uHTS can inspire novel functional metagenomics approaches to identify natural biocatalysts for novel chemical transformations.
Collapse
Affiliation(s)
- Ulrich Markel
- Institute of Biotechnology, RWTH Aachen University, Worringer Weg 3, 52074 Aachen, Germany.
| | | | | | | | | | | |
Collapse
|
18
|
Teo AJT, Tan SH, Nguyen NT. On-Demand Droplet Merging with an AC Electric Field for Multiple-Volume Droplet Generation. Anal Chem 2020; 92:1147-1153. [PMID: 31763821 DOI: 10.1021/acs.analchem.9b04219] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
We introduce a unique system to achieve on-demand droplet merging and splitting using a perpendicular AC electric field. The working mechanism involves a micropillar to split droplets, followed by electrocoalescence using an AC electric field. Adjusting the parameters of the AC signal and conductivity of the fluid result in different merging regimes. We observed a minimum threshold voltage and a strong influence of the surfactant. We hypothesize that the merging process is caused by dipole-dipole coalescence between the daughter droplets. At the same time, adjustment of the conductivity reveals a shift in the merging regimes and can be explained with an electric circuit diagram. Size-based sorting using this merging phenomenon is subsequently demonstrated, where alternate, single, double, and triple droplets sorting were achieved. The concept presented in this paper is potentially useful for drug dispensing or multivolume digital polymerase chain reaction, as droplets of multiple sizes can be generated simultaneously.
Collapse
Affiliation(s)
- Adrian J T Teo
- Queensland Micro- and Nanotechnology Centre , Griffith University , 170 Kessels Road Queensland 4111 , Brisbane , Australia
| | - Say Hwa Tan
- Queensland Micro- and Nanotechnology Centre , Griffith University , 170 Kessels Road Queensland 4111 , Brisbane , Australia
| | - Nam-Trung Nguyen
- Queensland Micro- and Nanotechnology Centre , Griffith University , 170 Kessels Road Queensland 4111 , Brisbane , Australia
| |
Collapse
|
19
|
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.
Collapse
|
20
|
Schütz SS, Beneyton T, Baret JC, Schneider TM. Rational design of a high-throughput droplet sorter. LAB ON A CHIP 2019; 19:2220-2232. [PMID: 31157806 DOI: 10.1039/c9lc00149b] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
The high-throughput selection of individual droplets is an essential function in droplet-based microfluidics. Fluorescence-activated droplet sorting is achieved using electric fields triggered at rates up to 30 kHz, providing the ultra-high throughput relevant in applications where large libraries of compounds or cells must be analyzed. To achieve such sorting frequencies, electrodes have to create an electric field distribution that generates maximal actuating forces on the droplet while limiting the induced droplet deformation and avoid disintegration. We propose a metric characterizing the performance of an electrode design relative to the theoretical optimum and analyze existing devices using full 3D simulations of the electric fields. By combining parameter optimization with numerical simulation we derive rational design guidelines and propose optimized electrode configurations. When tested experimentally, the optimized design show significantly better performance than the standard designs.
Collapse
Affiliation(s)
- Simon S Schütz
- Emergent Complexity in Physical Systems Laboratory (ECPS), École Polytechnique Fédérale de Lausanne (EPFL), Station 9, 1015 Lausanne, Switzerland.
| | | | | | | |
Collapse
|
21
|
Sesen M, Fakhfouri A, Neild A. Coalescence of Surfactant-Stabilized Adjacent Droplets Using Surface Acoustic Waves. Anal Chem 2019; 91:7538-7545. [DOI: 10.1021/acs.analchem.8b05456] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
- Muhsincan Sesen
- Department of Mechanical and Aerospace Engineering, Monash University, Clayton, Victoria 3800, Australia
| | - Armaghan Fakhfouri
- Department of Mechanical and Aerospace Engineering, Monash University, Clayton, Victoria 3800, Australia
| | - Adrian Neild
- Department of Mechanical and Aerospace Engineering, Monash University, Clayton, Victoria 3800, Australia
| |
Collapse
|
22
|
Kleine-Brüggeney H, van Vliet LD, Mulas C, Gielen F, Agley CC, Silva JCR, Smith A, Chalut K, Hollfelder F. Long-Term Perfusion Culture of Monoclonal Embryonic Stem Cells in 3D Hydrogel Beads for Continuous Optical Analysis of Differentiation. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2019; 15:e1804576. [PMID: 30570812 DOI: 10.1002/smll.201804576] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2018] [Revised: 12/02/2018] [Indexed: 06/09/2023]
Abstract
Developmental cell biology requires technologies in which the fate of single cells is followed over extended time periods, to monitor and understand the processes of self-renewal, differentiation, and reprogramming. A workflow is presented, in which single cells are encapsulated into droplets (Ø: 80 µm, volume: ≈270 pL) and the droplet compartment is later converted to a hydrogel bead. After on-chip de-emulsification by electrocoalescence, these 3D scaffolds are subsequently arrayed on a chip for long-term perfusion culture to facilitate continuous cell imaging over 68 h. Here, the response of murine embryonic stem cells to different growth media, 2i and N2B27, is studied, showing that the exit from pluripotency can be monitored by fluorescence time-lapse microscopy, by immunostaining and by reverse-transcription and quantitative PCR (RT-qPCR). The defined 3D environment emulates the natural context of cell growth (e.g., in tissue) and enables the study of cell development in various matrices. The large scale of cell cultivation (in 2000 beads in parallel) may reveal infrequent events that remain undetected in lower throughput or ensemble studies. This platform will help to gain qualitative and quantitative mechanistic insight into the role of external factors on cell behavior.
Collapse
Affiliation(s)
- Hans Kleine-Brüggeney
- Department of Biochemistry, University of Cambridge, 80 Tennis Court Road, Cambridge, CB2 1GA, UK
| | - Liisa D van Vliet
- Department of Biochemistry, University of Cambridge, 80 Tennis Court Road, Cambridge, CB2 1GA, UK
| | - Carla Mulas
- Wellcome Trust/Medical Research Council Cambridge Stem Cell Institute, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QR, UK
| | - Fabrice Gielen
- Department of Biochemistry, University of Cambridge, 80 Tennis Court Road, Cambridge, CB2 1GA, UK
| | - Chibeza C Agley
- Wellcome Trust/Medical Research Council Cambridge Stem Cell Institute, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QR, UK
| | - José C R Silva
- Wellcome Trust/Medical Research Council Cambridge Stem Cell Institute, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QR, UK
| | - Austin Smith
- Department of Biochemistry, University of Cambridge, 80 Tennis Court Road, Cambridge, CB2 1GA, UK
- Wellcome Trust/Medical Research Council Cambridge Stem Cell Institute, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QR, UK
| | - Kevin Chalut
- Wellcome Trust/Medical Research Council Cambridge Stem Cell Institute, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QR, UK
- Department of Physics, University of Cambridge, 19 J J Thomson Avenue, Cambridge, CB3 0HE, UK
| | - Florian Hollfelder
- Department of Biochemistry, University of Cambridge, 80 Tennis Court Road, Cambridge, CB2 1GA, UK
| |
Collapse
|
23
|
Wink K, Mahler L, Beulig JR, Piendl SK, Roth M, Belder D. An integrated chip-mass spectrometry and epifluorescence approach for online monitoring of bioactive metabolites from incubated Actinobacteria in picoliter droplets. Anal Bioanal Chem 2018; 410:7679-7687. [PMID: 30269162 DOI: 10.1007/s00216-018-1383-1] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2018] [Revised: 09/10/2018] [Accepted: 09/14/2018] [Indexed: 12/11/2022]
Abstract
We present a lab-on-a-chip approach for the analysis of secondary metabolites produced in microfluidic droplets by simultaneous epifluorescence microscopy and electrospray ionization mass spectrometry (ESI-MS). The approach includes encapsulation and long-term off-chip incubation of microbes in surfactant-stabilized droplets followed by a transfer of droplets into a microfluidic chip for subsequent analysis. Before the reinjected droplets are spaced and electrosprayed from an integrated emitter into a mass spectrometer, the presence of fluorescent marker molecules is monitored nearly simultaneously with a custom-made portable epifluorescence microscope. This combined fluorescence and MS-detection setup allows the analysis of metabolites and fluorescent labels in a complex biological matrix at a single droplet level. Using hyphae of Streptomyces griseus, encapsulated in microfluidic droplets of ~ 200 picoliter as a model system, we show the detection of in situ produced streptomycin by ESI-MS and the feasibility of detecting fluorophores inside droplets shortly before they are electrosprayed. The presented method expands the analytical toolbox for the discovery of bioactive metabolites such as novel antibiotics, produced by microorganisms.
Collapse
Affiliation(s)
- Konstantin Wink
- Institute of Analytical Chemistry, University of Leipzig, Johannisallee 29, 04103, Leipzig, Germany
| | - Lisa Mahler
- Leibniz Institute for Natural Product Research and Infection Biology -Hans Knöll Institute-, Bio Pilot Plant, Jena, 07745, Germany
- Faculty of Biological Sciences, Friedrich Schiller University, 07745, Jena, Germany
| | - Julia R Beulig
- Institute of Analytical Chemistry, University of Leipzig, Johannisallee 29, 04103, Leipzig, Germany
| | - Sebastian K Piendl
- Institute of Analytical Chemistry, University of Leipzig, Johannisallee 29, 04103, Leipzig, Germany
| | - Martin Roth
- Leibniz Institute for Natural Product Research and Infection Biology -Hans Knöll Institute-, Bio Pilot Plant, Jena, 07745, Germany
| | - Detlev Belder
- Institute of Analytical Chemistry, University of Leipzig, Johannisallee 29, 04103, Leipzig, Germany.
| |
Collapse
|
24
|
Manipulation and separation of oil droplets by using asymmetric nano-orifice induced DC dielectrophoretic method. J Colloid Interface Sci 2018; 512:389-397. [DOI: 10.1016/j.jcis.2017.10.073] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2017] [Revised: 10/18/2017] [Accepted: 10/19/2017] [Indexed: 11/21/2022]
|
25
|
Srivastava A, Karthick S, Jayaprakash KS, Sen AK. Droplet Demulsification Using Ultralow Voltage-Based Electrocoalescence. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2018; 34:1520-1527. [PMID: 29236503 DOI: 10.1021/acs.langmuir.7b03323] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Demulsification of droplets stabilized with surfactant is very challenging due to their low surface energy. We report ultralow voltage-based electrocoalescence phenomenon for the demulsification of aqueous droplets with an aqueous stream. In the absence of electric field, due to the disjoining pressure resulting from the tail-tail interaction between the surfactant molecules present on the aqueous droplets and interface, coalescence of aqueous droplets with the aqueous stream is prevented. However, above a critical electric field, the electrical stress overcomes the disjoining pressure, thus leading to the droplet coalescence. The influence of surfactant concentration, droplet diameter, and velocity on the electrocoalescence phenomena is studied. The macroscopic contact between the aqueous droplet with the aqueous stream enables droplet coalescence at much lower voltage (10 to 90 V), which is at least two orders of magnitude smaller than voltages used in prior works (1.0 to 3.0 kV). The electrocoalescence phenomena is used for the extraction of microparticles encapsulated in aqueous droplets into the aqueous stream and size-based selective demulsification. A new paradigm of droplet electrocoalescence and content extraction is presented that would find significant applications in chemistry and biology.
Collapse
Affiliation(s)
- A Srivastava
- Department of Mechanical Engineering, Indian Institute of Technology Madras , Chennai 600036, India
| | - S Karthick
- Department of Mechanical Engineering, Indian Institute of Technology Madras , Chennai 600036, India
| | - K S Jayaprakash
- Department of Mechanical Engineering, Indian Institute of Technology Madras , Chennai 600036, India
| | - A K Sen
- Department of Mechanical Engineering, Indian Institute of Technology Madras , Chennai 600036, India
| |
Collapse
|
26
|
Jia Y, Ren Y, Hou L, Liu W, Deng X, Jiang H. Sequential Coalescence Enabled Two-Step Microreactions in Triple-Core Double-Emulsion Droplets Triggered by an Electric Field. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2017; 13:1702188. [PMID: 29044912 DOI: 10.1002/smll.201702188] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2017] [Revised: 08/09/2017] [Indexed: 06/07/2023]
Abstract
Advances in microfluidic emulsification have enabled the generation of exquisite multiple-core droplets, which are promising structures to accommodate microreactions. An essential requirement for conducting reactions is the sequential coalescence of the multiple cores encapsulated within these droplets, therefore, mixing the reagents together in a controlled sequence. Here, a microfluidic approach is reported for the conduction of two-step microreactions by electrically fusing three cores inside double-emulsion droplets. Using a microcapillary glass device, monodisperse water-in-oil-in-water droplets are fabricated with three compartmented reagents encapsulated inside. An AC electric field is then applied through a polydimethylsiloxane chip to trigger the sequential mixing of the reagents, where the precise sequence is guaranteed by the discrepancy of the volume or conductivity of the inner cores. A two-step reaction in each droplet is ensured by two times of core coalescence, which totally takes 20-40 s depending on varying conditions. The optimal parameters of the AC signal for the sequential fusion of the inner droplets are identified. Moreover, the capability of this technique is demonstrated by conducting an enzyme-catalyzed reaction used for glucose detection with the double-emulsion droplets. This technique should benefit a wide range of applications that require multistep reactions in micrometer scale.
Collapse
Affiliation(s)
- Yankai Jia
- School of Mechatronics Engineering, Harbin Institute of Technology, Harbin, 150001, China
| | - Yukun Ren
- School of Mechatronics Engineering, Harbin Institute of Technology, Harbin, 150001, China
| | - Likai Hou
- School of Mechatronics Engineering, Harbin Institute of Technology, Harbin, 150001, China
| | - Weiyu Liu
- School of Mechatronics Engineering, Harbin Institute of Technology, Harbin, 150001, China
| | - Xiaokang Deng
- School of Mechatronics Engineering, Harbin Institute of Technology, Harbin, 150001, China
| | - Hongyuan Jiang
- School of Mechatronics Engineering, Harbin Institute of Technology, Harbin, 150001, China
| |
Collapse
|
27
|
Feng S, Nguyen MN, Inglis DW. Microfluidic Droplet Extraction by Hydrophilic Membrane. MICROMACHINES 2017; 8:E331. [PMID: 30400521 PMCID: PMC6189788 DOI: 10.3390/mi8110331] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/26/2017] [Revised: 11/09/2017] [Accepted: 11/15/2017] [Indexed: 11/16/2022]
Abstract
Droplet-based microfluidics are capable of transporting very small amounts of fluid over long distances. This characteristic may be applied to conventional fluid delivery using needles if droplets can be reliably expelled from a microfluidic channel. In this paper, we demonstrate a system for the extraction of water droplets from an oil-phase in a polymer microfluidic device. A hydrophilic membrane with a strong preference for water over oil is integrated into a droplet microfluidic system and observed to allow the passage of the transported aqueous phase droplets while blocking the continuous phase. The oil breakthrough pressure of the membrane was observed to be 250 ± 20 kPa, a much greater pressure than anywhere within the microfluidic channel, thereby eliminating the possibility that oil will leak from the microchannel, a critical parameter if droplet transport is to be used in needle-based drug delivery.
Collapse
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.
| | - Micheal N Nguyen
- 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.
| |
Collapse
|
28
|
Carreras MP, Wang S. A multifunctional microfluidic platform for generation, trapping and release of droplets in a double laminar flow. J Biotechnol 2017; 251:106-111. [PMID: 28450257 DOI: 10.1016/j.jbiotec.2017.04.030] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2016] [Revised: 04/17/2017] [Accepted: 04/24/2017] [Indexed: 10/19/2022]
Abstract
Droplet microfluidics, involving micrometer-sized emulsion of droplets is a growing subfield of microfluidics which attracts broad interest due to its application on biological assays. Droplet-based systems have been used as microreactors as well as to encapsulate many biological entities for biomedical and biotechnological applications. Here, a novel microfluidic device is presented for the generation, trapping and release of aqueous including hydrogel droplets in a double laminar oil flow. This platform enables the storage and release of picoliter-sized droplets in two different carrier oils by using hydrodynamic forces without the need of electrical forces or optical actuators. Furthermore, this design allows droplets to be selectively and simultaneously exposed to two different conditions and collected on demand. Successful encapsulation of hepatoma H35 cells was performed on-chip. Viability of cell-laden droplets was performed off-chip to assess the potential applications in 3D encapsulation cell culture and drug discovery assays.
Collapse
Affiliation(s)
- Maria Pilar Carreras
- Department of Biomedical Engineering, City University of New York - City College, New York, NY 10031, USA
| | - Sihong Wang
- Department of Biomedical Engineering, City University of New York - City College, New York, NY 10031, USA.
| |
Collapse
|
29
|
Autour A, Ryckelynck M. Ultrahigh-Throughput Improvement and Discovery of Enzymes Using Droplet-Based Microfluidic Screening. MICROMACHINES 2017. [PMCID: PMC6189954 DOI: 10.3390/mi8040128] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Enzymes are extremely valuable tools for industrial, environmental, and biotechnological applications and there is a constant need for improving existing biological catalysts and for discovering new ones. Screening microbe or gene libraries is an efficient way of identifying new enzymes. In this view, droplet-based microfluidics appears to be one of the most powerful approaches as it allows inexpensive screenings in well-controlled conditions and an ultrahigh-throughput regime. This review aims to introduce the main microfluidic devices and concepts to be considered for such screening before presenting and discussing the latest successful applications of the technology for enzyme discovery.
Collapse
|
30
|
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.
Collapse
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
| |
Collapse
|
31
|
Deng NN, Wang W, Ju XJ, Xie R, Chu LY. Spontaneous transfer of droplets across microfluidic laminar interfaces. LAB ON A CHIP 2016; 16:4326-4332. [PMID: 27722415 DOI: 10.1039/c6lc01022a] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
The precise manipulation of droplets in microfluidics has revolutionized a myriad of drop-based technologies, such as multiple emulsion preparation, drop fusion, drop fission, drop trapping and drop sorting, which offer promising new opportunities in chemical and biological fields. In this paper, we present an interfacial-tension-directed strategy for the migration of droplets across liquid-liquid laminar streams. By carefully controlling the interfacial energies, droplets of phase A are able to pass across the laminar interfaces of two immiscible fluids from phase B to phase C due to a positive spreading coefficient of phase C over phase B. To demonstrate this, we successfully perform the transfer of water droplets across an oil-oil laminar interface and the transfer of oil droplets across an oil-water laminar interface. The whole transfer process is spontaneous and only takes about 50 ms. We find that the fluid dynamics have an impact on the transfer processes. Only if the flowrate ratios are well matched will the droplets pass through the laminar interface successfully. This interfacial-tension-directed transfer of droplets provides a versatile procedure to make new structures and control microreactions as exemplified by the fabrication of giant unilamellar vesicles and cell-laden microgels.
Collapse
Affiliation(s)
- Nan-Nan Deng
- School of Chemical Engineering, Sichuan University, Chengdu, Sichuan 610065, China.
| | - Wei Wang
- School of Chemical Engineering, Sichuan University, Chengdu, Sichuan 610065, China. and State Key Laboratory of Polymer Materials Engineering, Sichuan University, Chengdu, Sichuan 610065, China
| | - Xiao-Jie Ju
- School of Chemical Engineering, Sichuan University, Chengdu, Sichuan 610065, China. and State Key Laboratory of Polymer Materials Engineering, Sichuan University, Chengdu, Sichuan 610065, China
| | - Rui Xie
- School of Chemical Engineering, Sichuan University, Chengdu, Sichuan 610065, China. and State Key Laboratory of Polymer Materials Engineering, Sichuan University, Chengdu, Sichuan 610065, China
| | - Liang-Yin Chu
- School of Chemical Engineering, Sichuan University, Chengdu, Sichuan 610065, China. and State Key Laboratory of Polymer Materials Engineering, Sichuan University, Chengdu, Sichuan 610065, China and Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing, Jiangsu 211816, China
| |
Collapse
|
32
|
Del Ben F, Turetta M, Celetti G, Piruska A, Bulfoni M, Cesselli D, Huck WTS, Scoles G. A Method for Detecting Circulating Tumor Cells Based on the Measurement of Single-Cell Metabolism in Droplet-Based Microfluidics. Angew Chem Int Ed Engl 2016. [DOI: 10.1002/ange.201602328] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Affiliation(s)
- Fabio Del Ben
- Graduate School of Nanotechnology; University of Trieste; Via Valerio 2 Trieste Italy
- Dept. of Clinical Pathology; CRO Aviano; Via F. Gallini 2 33081 Aviano, PN Italy
| | - Matteo Turetta
- Institute of Anatomic Pathology; Dept. of Medical and Biological Sciences; Azienda Ospedaliero-Universitaria di Udine; 33100 Udine Italy
| | - Giorgia Celetti
- Radboud University; Institute for Molecules and Materials; Heyendaalseweg 135 6525AJ Nijmegen The Netherlands
| | - Aigars Piruska
- Radboud University; Institute for Molecules and Materials; Heyendaalseweg 135 6525AJ Nijmegen The Netherlands
| | - Michela Bulfoni
- Institute of Anatomic Pathology; Dept. of Medical and Biological Sciences; Azienda Ospedaliero-Universitaria di Udine; 33100 Udine Italy
| | - Daniela Cesselli
- Institute of Anatomic Pathology; Dept. of Medical and Biological Sciences; Azienda Ospedaliero-Universitaria di Udine; 33100 Udine Italy
| | - Wilhelm T. S. Huck
- Radboud University; Institute for Molecules and Materials; Heyendaalseweg 135 6525AJ Nijmegen The Netherlands
| | - Giacinto Scoles
- Institute of Anatomic Pathology; Dept. of Medical and Biological Sciences; Azienda Ospedaliero-Universitaria di Udine; 33100 Udine Italy
| |
Collapse
|
33
|
Del Ben F, Turetta M, Celetti G, Piruska A, Bulfoni M, Cesselli D, Huck WTS, Scoles G. A Method for Detecting Circulating Tumor Cells Based on the Measurement of Single-Cell Metabolism in Droplet-Based Microfluidics. Angew Chem Int Ed Engl 2016; 55:8581-4. [DOI: 10.1002/anie.201602328] [Citation(s) in RCA: 80] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2016] [Revised: 04/01/2016] [Indexed: 12/13/2022]
Affiliation(s)
- Fabio Del Ben
- Graduate School of Nanotechnology; University of Trieste; Via Valerio 2 Trieste Italy
- Dept. of Clinical Pathology; CRO Aviano; Via F. Gallini 2 33081 Aviano, PN Italy
| | - Matteo Turetta
- Institute of Anatomic Pathology; Dept. of Medical and Biological Sciences; Azienda Ospedaliero-Universitaria di Udine; 33100 Udine Italy
| | - Giorgia Celetti
- Radboud University; Institute for Molecules and Materials; Heyendaalseweg 135 6525AJ Nijmegen The Netherlands
| | - Aigars Piruska
- Radboud University; Institute for Molecules and Materials; Heyendaalseweg 135 6525AJ Nijmegen The Netherlands
| | - Michela Bulfoni
- Institute of Anatomic Pathology; Dept. of Medical and Biological Sciences; Azienda Ospedaliero-Universitaria di Udine; 33100 Udine Italy
| | - Daniela Cesselli
- Institute of Anatomic Pathology; Dept. of Medical and Biological Sciences; Azienda Ospedaliero-Universitaria di Udine; 33100 Udine Italy
| | - Wilhelm T. S. Huck
- Radboud University; Institute for Molecules and Materials; Heyendaalseweg 135 6525AJ Nijmegen The Netherlands
| | - Giacinto Scoles
- Institute of Anatomic Pathology; Dept. of Medical and Biological Sciences; Azienda Ospedaliero-Universitaria di Udine; 33100 Udine Italy
| |
Collapse
|
34
|
Phan HV, Alan T, Neild A. Droplet Manipulation Using Acoustic Streaming Induced by a Vibrating Membrane. Anal Chem 2016; 88:5696-703. [PMID: 27119623 DOI: 10.1021/acs.analchem.5b04481] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
We present a simple method for on-demand manipulation of aqueous droplets in oil. With numerical simulations and experiments, we show that a vibrating membrane can produce acoustic streaming. By making use of this vortical flow, we manage to repulse the droplets away from the membrane edges. Then, by simply aligning the membrane at 45° to the flow, the droplets can be forced to follow the membrane's boundaries, thus steering them across streamlines and even between different oil types. We also characterize the repulsion and steering effect with various excitation voltages at different water and oil flow rates. The maximum steering frequency we have achieved is 165 Hz. The system is extremely robust and reliable: the same membrane can be reused after many days and with different oils and/or surfactants at the same operating frequency.
Collapse
Affiliation(s)
- Hoang Van Phan
- Laboratory for Micro Systems, Department of Mechanical and Aerospace Engineering, Monash University , Clayton, Victoria 3800, Australia
| | - Tuncay Alan
- Laboratory for Micro Systems, Department of Mechanical and Aerospace Engineering, Monash University , Clayton, Victoria 3800, Australia
| | - Adrian Neild
- Laboratory for Micro Systems, Department of Mechanical and Aerospace Engineering, Monash University , Clayton, Victoria 3800, Australia
| |
Collapse
|
35
|
Hu R, Liu P, Chen P, Wu L, Wang Y, Feng X, Liu BF. Encapsulation of single cells into monodisperse droplets by fluorescence-activated droplet formation on a microfluidic chip. Talanta 2016; 153:253-9. [PMID: 27130116 DOI: 10.1016/j.talanta.2016.03.013] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2015] [Revised: 02/24/2016] [Accepted: 03/02/2016] [Indexed: 10/22/2022]
Abstract
Random compartmentalization of cells by common droplet formation methods, i.e., T-junction and flow-focusing, results in low occupancy of droplets by single cells. To resolve this issue, a fluorescence-activated droplet formation method was developed for the on-command generation of droplets and encapsulation of single cells. In this method, droplets containing one cell were generated by switching on/off a two-phase hydrodynamic gating valve upon optical detection of single cells. To evaluate the developed method, flow visualization experiments were conducted with fluorescein. Results indicated that picoliter droplets of uniform sizes (RSD<4.9%) could be generated. Encapsulation of single fluorescent polystyrene beads demonstrated an average of 94.3% droplets contained one bead. Further application of the developed methods to the compartmentalization of individual HeLa cells indicated 82.5% occupancy of droplets by single cells, representing a 3 fold increase in comparison to random compartmentalization.
Collapse
Affiliation(s)
- Rui Hu
- Britton Chance Center for Biomedical Photonics at Wuhan National Laboratory for Optoelectronics - Hubei Bioinformatics & Molecular Imaging Key Laboratory, Systems Biology Theme, Department of Biomedical Engineering, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, China; Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
| | - Pian Liu
- Cancer Center, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Pu Chen
- Britton Chance Center for Biomedical Photonics at Wuhan National Laboratory for Optoelectronics - Hubei Bioinformatics & Molecular Imaging Key Laboratory, Systems Biology Theme, Department of Biomedical Engineering, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Liang Wu
- Britton Chance Center for Biomedical Photonics at Wuhan National Laboratory for Optoelectronics - Hubei Bioinformatics & Molecular Imaging Key Laboratory, Systems Biology Theme, Department of Biomedical Engineering, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Yao Wang
- Britton Chance Center for Biomedical Photonics at Wuhan National Laboratory for Optoelectronics - Hubei Bioinformatics & Molecular Imaging Key Laboratory, Systems Biology Theme, Department of Biomedical Engineering, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Xiaojun Feng
- Britton Chance Center for Biomedical Photonics at Wuhan National Laboratory for Optoelectronics - Hubei Bioinformatics & Molecular Imaging Key Laboratory, Systems Biology Theme, Department of Biomedical Engineering, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, China.
| | - Bi-Feng Liu
- Britton Chance Center for Biomedical Photonics at Wuhan National Laboratory for Optoelectronics - Hubei Bioinformatics & Molecular Imaging Key Laboratory, Systems Biology Theme, Department of Biomedical Engineering, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, China
| |
Collapse
|
36
|
High-Throughput Screening in Protein Engineering: Recent Advances and Future Perspectives. Int J Mol Sci 2015; 16:24918-45. [PMID: 26492240 PMCID: PMC4632782 DOI: 10.3390/ijms161024918] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2015] [Revised: 10/13/2015] [Accepted: 10/13/2015] [Indexed: 11/17/2022] Open
Abstract
Over the last three decades, protein engineering has established itself as an important tool for the development of enzymes and (therapeutic) proteins with improved characteristics. New mutagenesis techniques and computational design tools have greatly aided in the advancement of protein engineering. Yet, one of the pivotal components to further advance protein engineering strategies is the high-throughput screening of variants. Compartmentalization is one of the key features allowing miniaturization and acceleration of screening. This review focuses on novel screening technologies applied in protein engineering, highlighting flow cytometry- and microfluidics-based platforms.
Collapse
|
37
|
Najah M, Calbrix R, Mahendra-Wijaya IP, Beneyton T, Griffiths AD, Drevelle A. Droplet-based microfluidics platform for ultra-high-throughput bioprospecting of cellulolytic microorganisms. ACTA ACUST UNITED AC 2015; 21:1722-32. [PMID: 25525991 DOI: 10.1016/j.chembiol.2014.10.020] [Citation(s) in RCA: 66] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2014] [Revised: 09/30/2014] [Accepted: 10/20/2014] [Indexed: 01/05/2023]
Abstract
Discovery of microorganisms producing enzymes that can efficiently hydrolyze cellulosic biomass is of great importance for biofuel production. To date, however, only a miniscule fraction of natural biodiversity has been tested because of the relatively low throughput of screening systems and their limitation to screening only culturable microorganisms. Here, we describe an ultra-high-throughput droplet-based microfluidic system that allowed the screening of over 100,000 cells in less than 20 min. Uncultured bacteria from a wheat stubble field were screened directly by compartmentalization of single bacteria in 20 pl droplets containing a fluorogenic cellobiohydrolase substrate. Sorting of droplets based on cellobiohydrolase activity resulted in a bacterial population with 17- and 7-fold higher cellobiohydrolase and endogluconase activity, respectively, and very different taxonomic diversity than when selected for growth on medium containing starch and carboxymethylcellulose as carbon source.
Collapse
Affiliation(s)
- Majdi Najah
- Institut de Science et d'Ingénierie Supramoléculaires (ISIS), Université de Strasbourg, CNRS UMR 7006, 8 allée Gaspard Monge, 67083 Strasbourg Cedex, France; Division Biotechnologies, Ets. J. Soufflet, quai Sarrail, 10400 Nogent-sur-Seine, France
| | - Raphaël Calbrix
- Institut de Science et d'Ingénierie Supramoléculaires (ISIS), Université de Strasbourg, CNRS UMR 7006, 8 allée Gaspard Monge, 67083 Strasbourg Cedex, France
| | - I Putu Mahendra-Wijaya
- Institut de Science et d'Ingénierie Supramoléculaires (ISIS), Université de Strasbourg, CNRS UMR 7006, 8 allée Gaspard Monge, 67083 Strasbourg Cedex, France; Division Biotechnologies, Ets. J. Soufflet, quai Sarrail, 10400 Nogent-sur-Seine, France
| | - Thomas Beneyton
- École Supérieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI ParisTech), CNRS UMR 8231, 10 rue Vauquelin, 75231 Paris Cedex 05, France
| | - Andrew D Griffiths
- Institut de Science et d'Ingénierie Supramoléculaires (ISIS), Université de Strasbourg, CNRS UMR 7006, 8 allée Gaspard Monge, 67083 Strasbourg Cedex, France; École Supérieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI ParisTech), CNRS UMR 8231, 10 rue Vauquelin, 75231 Paris Cedex 05, France.
| | - Antoine Drevelle
- Institut de Science et d'Ingénierie Supramoléculaires (ISIS), Université de Strasbourg, CNRS UMR 7006, 8 allée Gaspard Monge, 67083 Strasbourg Cedex, France; Division Biotechnologies, Ets. J. Soufflet, quai Sarrail, 10400 Nogent-sur-Seine, France.
| |
Collapse
|
38
|
Ahn MM, Im DJ, Yoo BS, Kang IS. Characterization of electrode alignment for optimal droplet charging and actuation in droplet-based microfluidic system. Electrophoresis 2015; 36:2086-93. [DOI: 10.1002/elps.201500141] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2015] [Revised: 05/06/2015] [Accepted: 05/06/2015] [Indexed: 11/06/2022]
Affiliation(s)
- Myung Mo Ahn
- Department of Chemical Engineering; Pohang University of Science and Technology; Pohang South Korea
| | - Do Jin Im
- Department of Chemical Engineering; Pukyong National University; Nam-Gu. Busan South Korea
| | - Byeong Sun Yoo
- Department of Chemical Engineering; Pohang University of Science and Technology; Pohang South Korea
| | - In Seok Kang
- Department of Chemical Engineering; Pohang University of Science and Technology; Pohang South Korea
| |
Collapse
|
39
|
Dissecting enzyme function with microfluidic-based deep mutational scanning. Proc Natl Acad Sci U S A 2015; 112:7159-64. [PMID: 26040002 DOI: 10.1073/pnas.1422285112] [Citation(s) in RCA: 143] [Impact Index Per Article: 15.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Natural enzymes are incredibly proficient catalysts, but engineering them to have new or improved functions is challenging due to the complexity of how an enzyme's sequence relates to its biochemical properties. Here, we present an ultrahigh-throughput method for mapping enzyme sequence-function relationships that combines droplet microfluidic screening with next-generation DNA sequencing. We apply our method to map the activity of millions of glycosidase sequence variants. Microfluidic-based deep mutational scanning provides a comprehensive and unbiased view of the enzyme function landscape. The mapping displays expected patterns of mutational tolerance and a strong correspondence to sequence variation within the enzyme family, but also reveals previously unreported sites that are crucial for glycosidase function. We modified the screening protocol to include a high-temperature incubation step, and the resulting thermotolerance landscape allowed the discovery of mutations that enhance enzyme thermostability. Droplet microfluidics provides a general platform for enzyme screening that, when combined with DNA-sequencing technologies, enables high-throughput mapping of enzyme sequence space.
Collapse
|
40
|
Ryckelynck M, Baudrey S, Rick C, Marin A, Coldren F, Westhof E, Griffiths AD. Using droplet-based microfluidics to improve the catalytic properties of RNA under multiple-turnover conditions. RNA (NEW YORK, N.Y.) 2015; 21:458-69. [PMID: 25605963 PMCID: PMC4338340 DOI: 10.1261/rna.048033.114] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/08/2014] [Accepted: 12/09/2014] [Indexed: 05/19/2023]
Abstract
In vitro evolution methodologies are powerful approaches to identify RNA with new functionalities. While Systematic Evolution of Ligands by Exponential enrichment (SELEX) is an efficient approach to generate new RNA aptamers, it is less suited for the isolation of efficient ribozymes as it does not select directly for the catalysis. In vitro compartmentalization (IVC) in aqueous droplets in emulsions allows catalytic RNAs to be selected under multiple-turnover conditions but suffers severe limitations that can be overcome using the droplet-based microfluidics workflow described in this paper. Using microfluidics, millions of genes in a library can be individually compartmentalized in highly monodisperse aqueous droplets and serial operations performed on them. This allows the different steps of the evolution process (gene amplification, transcription, and phenotypic assay) to be uncoupled, making the method highly flexible, applicable to the selection and evolution of a variety of RNAs, and easily adaptable for evolution of DNA or proteins. To demonstrate the method, we performed cycles of random mutagenesis and selection to evolve the X-motif, a ribozyme which, like many ribozymes selected using SELEX, has limited multiple-turnover activity. This led to the selection of variants, likely to be the optimal ribozymes that can be generated using point mutagenesis alone, with a turnover number under multiple-turnover conditions, k(ss) cat, ∼ 28-fold higher than the original X-motif, primarily due to an increase in the rate of product release, the rate-limiting step in the multiple-turnover reaction.
Collapse
Affiliation(s)
- Michael Ryckelynck
- Architecture et Réactivité de l'ARN, CNRS UPR 9002, Université de Strasbourg, 67084 Strasbourg, France Institut de Science et d'Ingénierie Supramoléculaires (ISIS), CNRS UMR 7006, Université de Strasbourg, 67083 Strasbourg, France
| | - Stéphanie Baudrey
- Architecture et Réactivité de l'ARN, CNRS UPR 9002, Université de Strasbourg, 67084 Strasbourg, France
| | - Christian Rick
- Architecture et Réactivité de l'ARN, CNRS UPR 9002, Université de Strasbourg, 67084 Strasbourg, France Institut de Science et d'Ingénierie Supramoléculaires (ISIS), CNRS UMR 7006, Université de Strasbourg, 67083 Strasbourg, France
| | - Annick Marin
- Institut de Science et d'Ingénierie Supramoléculaires (ISIS), CNRS UMR 7006, Université de Strasbourg, 67083 Strasbourg, France
| | - Faith Coldren
- Institut de Science et d'Ingénierie Supramoléculaires (ISIS), CNRS UMR 7006, Université de Strasbourg, 67083 Strasbourg, France
| | - Eric Westhof
- Architecture et Réactivité de l'ARN, CNRS UPR 9002, Université de Strasbourg, 67084 Strasbourg, France
| | - Andrew D Griffiths
- Institut de Science et d'Ingénierie Supramoléculaires (ISIS), CNRS UMR 7006, Université de Strasbourg, 67083 Strasbourg, France Ecole Supérieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI ParisTech), CNRS UMR 8231, 75231 Paris, France
| |
Collapse
|
41
|
Abstract
Fluorescence-activated droplet sorting is an important tool for droplet microfluidic workflows, but published approaches are unable to surpass throughputs of a few kilohertz. We present a new geometry that replaces the hard divider separating the outlets with a gapped divider, allowing sorting over ten times faster.
Collapse
Affiliation(s)
- Adam Sciambi
- Department of Bioengineering and Therapeutic Sciences, California Institute for Quantitative Biosciences, University of California, San Francisco, California, 94158 USA.
| | | |
Collapse
|
42
|
Schönberg JN, Brandstetter T, Rühe J. Particle Extraction in Plug-based Microfluidics. ACTA ACUST UNITED AC 2015. [DOI: 10.1016/j.proeng.2015.08.574] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
43
|
Real-time monitoring of quorum sensing in 3D-printed bacterial aggregates using scanning electrochemical microscopy. Proc Natl Acad Sci U S A 2014; 111:18255-60. [PMID: 25489085 DOI: 10.1073/pnas.1421211111] [Citation(s) in RCA: 117] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Microbes frequently live in nature as small, densely packed aggregates containing ∼10(1)-10(5) cells. These aggregates not only display distinct phenotypes, including resistance to antibiotics, but also, serve as building blocks for larger biofilm communities. Aggregates within these larger communities display nonrandom spatial organization, and recent evidence indicates that this spatial organization is critical for fitness. Studying single aggregates as well as spatially organized aggregates remains challenging because of the technical difficulties associated with manipulating small populations. Micro-3D printing is a lithographic technique capable of creating aggregates in situ by printing protein-based walls around individual cells or small populations. This 3D-printing strategy can organize bacteria in complex arrangements to investigate how spatial and environmental parameters influence social behaviors. Here, we combined micro-3D printing and scanning electrochemical microscopy (SECM) to probe quorum sensing (QS)-mediated communication in the bacterium Pseudomonas aeruginosa. Our results reveal that QS-dependent behaviors are observed within aggregates as small as 500 cells; however, aggregates larger than 2,000 bacteria are required to stimulate QS in neighboring aggregates positioned 8 μm away. These studies provide a powerful system to analyze the impact of spatial organization and aggregate size on microbial behaviors.
Collapse
|
44
|
Rendl M, Brandstetter T, Rühe J. Solid-phase extraction in segmented flow. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2014; 30:12804-12811. [PMID: 25300748 DOI: 10.1021/la502645z] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Two-phase flow systems are increasingly popular for miniaturized, high-throughput performance of analytical or chemical reactions. In this contribution, we extend a previously described method that allows to increase the range of applications of heterogeneous reactions in two-phase flow, i.e., reactions that rely on isolation and purification of the compound of interest for downstream analysis. Our concept is based on liquid plugs, which serve as miniaturized compartments for the analytical reactions. Purification of the target compound is achieved by extracting the analyte from the aqueous compartments using magnetic beads as solid carriers. In the present paper, we elucidate the influence of parameters such as the polarity of the liquid/liquid and solid/liquid interfaces, the magnetic forces and the fluidic conditions onto the extraction performance. The conditions for reliable extraction and purification of the target compounds are determined. Furthermore, we investigate how to facilitate breaking of the plugs through reduction of the surface tension of the solid/liquid interface. When a lower surface tension is employed, a smaller number of beads is required for the extraction process, which implies a higher sensitivity of the device. In addition, we generate channels with different surface chemistries, which are able to manipulate the flow of the two immiscible liquids. We describe a very simple way to generate such devices and show that we can achieve a transition from segmented flow of plugs to a side-by side flow of the two immiscible liquids, a key requirement for the purification of the compounds.
Collapse
Affiliation(s)
- Martin Rendl
- Laboratory for Chemistry and Physics of Interfaces, Department of Microsystems Engineering (IMTEK), University of Freiburg , Georges-Köhler-Allee 103, D-79110 Freiburg, Germany
| | | | | |
Collapse
|
45
|
|
46
|
Baldygin A, Nobes DS, Mitra SK. New Laboratory Core Flooding Experimental System. Ind Eng Chem Res 2014. [DOI: 10.1021/ie501866e] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Aleksey Baldygin
- Micro and Nanoscale
Transport Laboratory, Department of Mechanical Engineering, University of Alberta, Edmonton, Alberta T6G 2G8, Canada
| | - David S. Nobes
- Optical Diagnostic
Group, Department of Mechanical Engineering, University of Alberta, Edmonton, Alberta T6G 2G8, Canada
| | - Sushanta K. Mitra
- Micro and Nanoscale
Transport Laboratory, Department of Mechanical Engineering, University of Alberta, Edmonton, Alberta T6G 2G8, Canada
| |
Collapse
|
47
|
Chokkalingam V, Ma Y, Thiele J, Schalk W, Tel J, Huck WTS. An electro-coalescence chip for effective emulsion breaking in droplet microfluidics. LAB ON A CHIP 2014; 14:2398-402. [PMID: 24889537 DOI: 10.1039/c4lc00365a] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Droplet-based microfluidics is increasingly used for biological applications, where the recovery of cells or particles after an experiment or assay is desirable. Here, we present an electro-demulsification chip which circumvents the use of harsh chemicals and multiple washing/centrifugation steps and offers a mild way for extracting cells and polymer particles into an aqueous phase from microfluidic water-in-oil emulsions.
Collapse
|
48
|
|
49
|
Zhou H, Li G, Yao S. A droplet-based pH regulator in microfluidics. LAB ON A CHIP 2014; 14:1917-1922. [PMID: 24745036 DOI: 10.1039/c3lc51442k] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
In this paper, we develop a strategy to form on-demand droplets with specific pH values. The pH control is based on electrolysis of water in microfluidics, and the produced hydrogen and hydroxyl ions are separated and confined in individual containers during the droplet generation, triggered by a pressure pulse. By tuning the applied voltages and pressure pulses, we can control on demand the pH value in a droplet.
Collapse
Affiliation(s)
- Hongbo Zhou
- Department of Mechanical and Aerospace Engineering, Hong Kong University of Science and Technology, Hong Kong, China.
| | | | | |
Collapse
|
50
|
Wu L, Chen P, Dong Y, Feng X, Liu BF. Encapsulation of single cells on a microfluidic device integrating droplet generation with fluorescence-activated droplet sorting. Biomed Microdevices 2014; 15:553-60. [PMID: 23404263 DOI: 10.1007/s10544-013-9754-z] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Encapsulation of single cells is a challenging task in droplet microfluidics due to the random compartmentalization of cells dictated by Poisson statistics. In this paper, a microfluidic device was developed to improve the single-cell encapsulation rate by integrating droplet generation with fluorescence-activated droplet sorting. After cells were loaded into aqueous droplets by hydrodynamic focusing, an on-flight fluorescence-activated sorting process was conducted to isolate droplets containing one cell. Encapsulation of fluorescent polystyrene beads was investigated to evaluate the developed method. A single-bead encapsulation rate of more than 98 % was achieved under the optimized conditions. Application to encapsulate single HeLa cells was further demonstrated with a single-cell encapsulation rate of 94.1 %, which is about 200 % higher than those obtained by random compartmentalization. We expect this new method to provide a useful platform for encapsulating single cells, facilitating the development of high-throughput cell-based assays.
Collapse
Affiliation(s)
- Liang Wu
- Department of Biomedical Engineering, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, China
| | | | | | | | | |
Collapse
|