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Orabi M, Lo JF. Emerging Advances in Microfluidic Hydrogel Droplets for Tissue Engineering and STEM Cell Mechanobiology. Gels 2023; 9:790. [PMID: 37888363 PMCID: PMC10606214 DOI: 10.3390/gels9100790] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2023] [Revised: 09/26/2023] [Accepted: 09/27/2023] [Indexed: 10/28/2023] Open
Abstract
Hydrogel droplets are biodegradable and biocompatible materials with promising applications in tissue engineering, cell encapsulation, and clinical treatments. They represent a well-controlled microstructure to bridge the spatial divide between two-dimensional cell cultures and three-dimensional tissues, toward the recreation of entire organs. The applications of hydrogel droplets in regenerative medicine require a thorough understanding of microfluidic techniques, the biocompatibility of hydrogel materials, and droplet production and manipulation mechanisms. Although hydrogel droplets were well studied, several emerging advances promise to extend current applications to tissue engineering and beyond. Hydrogel droplets can be designed with high surface-to-volume ratios and a variety of matrix microstructures. Microfluidics provides precise control of the flow patterns required for droplet generation, leading to tight distributions of particle size, shape, matrix, and mechanical properties in the resultant microparticles. This review focuses on recent advances in microfluidic hydrogel droplet generation. First, the theoretical principles of microfluidics, materials used in fabrication, and new 3D fabrication techniques were discussed. Then, the hydrogels used in droplet generation and their cell and tissue engineering applications were reviewed. Finally, droplet generation mechanisms were addressed, such as droplet production, droplet manipulation, and surfactants used to prevent coalescence. Lastly, we propose that microfluidic hydrogel droplets can enable novel shear-related tissue engineering and regeneration studies.
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Affiliation(s)
| | - Joe F. Lo
- Department of Mechanical Engineering, University of Michigan, 4901 Evergreen Road, Dearborn, MI 48128, USA;
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2
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Tevlek A, Kecili S, Ozcelik OS, Kulah H, Tekin HC. Spheroid Engineering in Microfluidic Devices. ACS OMEGA 2023; 8:3630-3649. [PMID: 36743071 PMCID: PMC9893254 DOI: 10.1021/acsomega.2c06052] [Citation(s) in RCA: 13] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2022] [Accepted: 12/12/2022] [Indexed: 05/27/2023]
Abstract
Two-dimensional (2D) cell culture techniques are commonly employed to investigate biophysical and biochemical cellular responses. However, these culture methods, having monolayer cells, lack cell-cell and cell-extracellular matrix interactions, mimicking the cell microenvironment and multicellular organization. Three-dimensional (3D) cell culture methods enable equal transportation of nutrients, gas, and growth factors among cells and their microenvironment. Therefore, 3D cultures show similar cell proliferation, apoptosis, and differentiation properties to in vivo. A spheroid is defined as self-assembled 3D cell aggregates, and it closely mimics a cell microenvironment in vitro thanks to cell-cell/matrix interactions, which enables its use in several important applications in medical and clinical research. To fabricate a spheroid, conventional methods such as liquid overlay, hanging drop, and so forth are available. However, these labor-intensive methods result in low-throughput fabrication and uncontrollable spheroid sizes. On the other hand, microfluidic methods enable inexpensive and rapid fabrication of spheroids with high precision. Furthermore, fabricated spheroids can also be cultured in microfluidic devices for controllable cell perfusion, simulation of fluid shear effects, and mimicking of the microenvironment-like in vivo conditions. This review focuses on recent microfluidic spheroid fabrication techniques and also organ-on-a-chip applications of spheroids, which are used in different disease modeling and drug development studies.
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Affiliation(s)
- Atakan Tevlek
- METU
MEMS Research and Application Center, Ankara 06800, Turkey
| | - Seren Kecili
- The
Department of Bioengineering, Izmir Institute
of Technology, Urla, Izmir 35430, Turkey
| | - Ozge S. Ozcelik
- The
Department of Bioengineering, Izmir Institute
of Technology, Urla, Izmir 35430, Turkey
| | - Haluk Kulah
- METU
MEMS Research and Application Center, Ankara 06800, Turkey
- The
Department of Electrical and Electronics Engineering, Middle East Technical University, Ankara 06800, Turkey
| | - H. Cumhur Tekin
- METU
MEMS Research and Application Center, Ankara 06800, Turkey
- The
Department of Bioengineering, Izmir Institute
of Technology, Urla, Izmir 35430, Turkey
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3
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Vasamsetti BMK, Kim YJ, Kang JH, Choi JW. Analysis of Phosphatase Activity in a Droplet-Based Microfluidic Chip. BIOSENSORS 2022; 12:bios12090740. [PMID: 36140125 PMCID: PMC9496282 DOI: 10.3390/bios12090740] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/27/2022] [Revised: 08/22/2022] [Accepted: 09/05/2022] [Indexed: 11/27/2022]
Abstract
We report analysis of phosphatase activity and inhibition on droplet-based microfluidic chips. Phosphatases are such attractive potential drug targets because abnormal phosphatase activity has been implicated in a variety of diseases including cancer, neurological disorders, diabetes, osteoporosis, and obesity. So far, several methods for assessing phosphatase activity have been reported. However, they require a large sample volume and additional chemical modifications such as fluorescent dye conjugation and nanomaterial conjugation, and are not cost-effective. In this study, we used an artificial phosphatase substrate 3-O-methylfluorescein phosphate as a fluorescent reporter and dual specificity phosphatase 22. Using these materials, the phosphatase assay was performed from approximately 340.4 picoliter (pL) droplets generated at a frequency of ~40 hertz (Hz) in a droplet-based microfluidic chip. To evaluate the suitability of droplet-based platform for screening phosphatase inhibitors, a dose–response inhibition study was performed with ethyl-3,4-dephostatin and the half-maximal inhibitory concentration (IC50) was calculated as 5.79 ± 1.09 μM. The droplet-based results were compared to microplate-based experiments, which showed agreement. The droplet-based phosphatase assay proposed here is simple, reproducible, and generates enormous data sets within the limited sample and reagent volumes.
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Affiliation(s)
- Bala Murali Krishna Vasamsetti
- Department of Biomedical Science, Cheongju University, Cheongju 28160, Korea
- Toxicity and Risk Assessment Division, Department of Agro-Food Safety and Crop Protection, National Institute of Agricultural Sciences, Rural Development Administration, Wanju-gun 55365, Korea
| | - Yeon-Jun Kim
- Department of Biomedical Science, Cheongju University, Cheongju 28160, Korea
| | - Jung Hoon Kang
- Department of Biomedical Science, Cheongju University, Cheongju 28160, Korea
| | - Jae-Won Choi
- Department of Biomedical Science, Cheongju University, Cheongju 28160, Korea
- Department of Bioindustrial Engineering, Cheongju University, Cheongju 28503, Korea
- Correspondence: or ; Tel.: +82-43-229-8528
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Zhang H, Rong G, Bian S, Sawan M. Lab-on-Chip Microsystems for Ex Vivo Network of Neurons Studies: A Review. Front Bioeng Biotechnol 2022; 10:841389. [PMID: 35252149 PMCID: PMC8888888 DOI: 10.3389/fbioe.2022.841389] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Accepted: 01/17/2022] [Indexed: 11/13/2022] Open
Abstract
Increasing population is suffering from neurological disorders nowadays, with no effective therapy available to treat them. Explicit knowledge of network of neurons (NoN) in the human brain is key to understanding the pathology of neurological diseases. Research in NoN developed slower than expected due to the complexity of the human brain and the ethical considerations for in vivo studies. However, advances in nanomaterials and micro-/nano-microfabrication have opened up the chances for a deeper understanding of NoN ex vivo, one step closer to in vivo studies. This review therefore summarizes the latest advances in lab-on-chip microsystems for ex vivo NoN studies by focusing on the advanced materials, techniques, and models for ex vivo NoN studies. The essential methods for constructing lab-on-chip models are microfluidics and microelectrode arrays. Through combination with functional biomaterials and biocompatible materials, the microfluidics and microelectrode arrays enable the development of various models for ex vivo NoN studies. This review also includes the state-of-the-art brain slide and organoid-on-chip models. The end of this review discusses the previous issues and future perspectives for NoN studies.
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Affiliation(s)
| | | | - Sumin Bian
- CenBRAIN Lab, School of Engineering, Westlake University, Hangzhou, China
| | - Mohamad Sawan
- CenBRAIN Lab, School of Engineering, Westlake University, Hangzhou, China
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5
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Wang M, Liao X, Tchounwou PB, Liu YM. Coupling a droplet generator with conventional ESI-MS for quantitative analysis of small-volume samples. Anal Bioanal Chem 2022; 414:1809-1817. [PMID: 35061061 PMCID: PMC8828272 DOI: 10.1007/s00216-021-03808-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2021] [Revised: 11/22/2021] [Accepted: 11/25/2021] [Indexed: 02/03/2023]
Abstract
Quantitative mass spectrometric analysis of small-volume samples (e.g., < 1 μL) has been a challenge mainly due to the difficulties with sample handling and its injection into the system for analysis. Herein we report a microfluidic analytical platform coupling a droplet generator with conventional electrospray ionization-mass spectrometry (ESI-MS) that enables multiple analyses of a μL-sized sample with sensitivity and repeatability. In an analysis by droplet generator-assisted ESI-MS (DG-ESI-MS), a sample of μL volume is pulled into a sampling capillary and its equal nL-sized portions are generated by a droplet generator and analyzed by ESI-MS at time intervals of choice. The droplet generator is made of PMMA sheets by laser engraving conveniently and at a low cost. In a study to achieve effective ESI-MS detection of water-in-oil droplets, it's found that the problem of MS signal suppression by oil can be solved by using an appropriate organic carrier with ESI-enhancing additives. The proposed DG-ESI-MS method has linear calibration curves for both adenine and phenylalanine with LODs at the sub-μM level. Application of the present analytical platform for monitoring substrate concentration changes in an enzymatic reaction solution of 3 μL is demonstrated.
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Affiliation(s)
- Meiyuan Wang
- Department of Chemistry and Biochemistry, Jackson State University, Jackson, MS 39217, USA
| | - Xun Liao
- Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, Sichuan 610041, China
| | - Paul B. Tchounwou
- Department of Biology, Jackson State University, 1400 Lynch Street, Jackson, MS 39217, USA
| | - Yi-Ming Liu
- Department of Chemistry and Biochemistry, Jackson State University, Jackson, MS 39217, USA
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Amirifar L, Besanjideh M, Nasiri R, Shamloo A, Nasrollahi F, de Barros NR, Davoodi E, Erdem A, Mahmoodi M, Hosseini V, Montazerian H, Jahangiry J, Darabi MA, Haghniaz R, Dokmeci MR, Annabi N, Ahadian S, Khademhosseini A. Droplet-based microfluidics in biomedical applications. Biofabrication 2021; 14. [PMID: 34781274 DOI: 10.1088/1758-5090/ac39a9] [Citation(s) in RCA: 43] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2021] [Accepted: 11/15/2021] [Indexed: 11/11/2022]
Abstract
Droplet-based microfluidic systems have been employed to manipulate discrete fluid volumes with immiscible phases. Creating the fluid droplets at microscale has led to a paradigm shift in mixing, sorting, encapsulation, sensing, and designing high throughput devices for biomedical applications. Droplet microfluidics has opened many opportunities in microparticle synthesis, molecular detection, diagnostics, drug delivery, and cell biology. In the present review, we first introduce standard methods for droplet generation (i.e., passive and active methods) and discuss the latest examples of emulsification and particle synthesis approaches enabled by microfluidic platforms. Then, the applications of droplet-based microfluidics in different biomedical applications are detailed. Finally, a general overview of the latest trends along with the perspectives and future potentials in the field are provided.
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Affiliation(s)
- Leyla Amirifar
- Mechanical Engineering, Sharif University of Technology, Tehran, Iran, Tehran, 11365-11155, Iran (the Islamic Republic of)
| | - Mohsen Besanjideh
- Department of Mechanical Engineering, Sharif University of Technology, Tehran, Tehran, 11365-11155, Iran (the Islamic Republic of)
| | - Rohollah Nasiri
- Department of Mechanical Engineering, Sharif University of Technology, Tehran, Tehran, 11365-11155, Iran (the Islamic Republic of)
| | - Amir Shamloo
- Department of Mechanical Engineering, Sharif University of Technology, Tehran, Tehran, 11365-11155, Iran (the Islamic Republic of)
| | | | - Natan Roberto de Barros
- Terasaki Institute for Biomedical Innovation (TIBI), Los Angeles, Los Angeles, 90024, UNITED STATES
| | - Elham Davoodi
- Bioengineering, University of California - Los Angeles, Los Angeles, Los Angeles, 90095, UNITED STATES
| | - Ahmet Erdem
- Bioengineering, University of California - Los Angeles, Los Angeles, Los Angeles, 90095, UNITED STATES
| | | | - Vahid Hosseini
- Terasaki Institute for Biomedical Innovation (TIBI), Los Angeles, Los Angeles, 90024, UNITED STATES
| | - Hossein Montazerian
- Bioengineering, University of California - Los Angeles, Los Angeles, Los Angeles, 90095, UNITED STATES
| | - Jamileh Jahangiry
- University of California - Los Angeles, Los Angeles, Los Angeles, 90095, UNITED STATES
| | | | - Reihaneh Haghniaz
- Terasaki Institute for Biomedical Innovation (TIBI), Los Angeles, Los Angeles, 90024, UNITED STATES
| | - Mehmet R Dokmeci
- Terasaki Institute for Biomedical Innovation (TIBI), Los Angeles, Los Angeles, 90024, UNITED STATES
| | - Nasim Annabi
- Chemical Engineering, UCLA, Los Angeles, Los Angeles, California, 90095, UNITED STATES
| | - Samad Ahadian
- Terasaki Institute for Biomedical Innovation (TIBI), Los Angeles, Los Angeles, 90024, UNITED STATES
| | - Ali Khademhosseini
- Terasaki Institute for Biomedical Innovation (TIBI), Los Angeles, Los Angeles, 90024, UNITED STATES
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Amiri Roodan V, Gómez-Pastora J, Karampelas IH, González-Fernández C, Bringas E, Ortiz I, Chalmers JJ, Furlani EP, Swihart MT. Formation and manipulation of ferrofluid droplets with magnetic fields in a microdevice: a numerical parametric study. SOFT MATTER 2020; 16:9506-9518. [PMID: 32966533 PMCID: PMC8256729 DOI: 10.1039/d0sm01426e] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
We present a numerical model that describes the microfluidic generation and manipulation of ferrofluid droplets under an external magnetic field. We developed a numerical Computational Fluid Dynamics (CFD) analysis for predicting and optimizing continuous flow generation and processing of ferrofluid droplets with and without the presence of a permanent magnet. More specifically, we explore the dynamics of oil-based ferrofluid droplets within an aqueous continuous phase under an external inhomogeneous magnetic field. The developed model determines the effect of the magnetic field on the droplet generation, which is carried out in a flow-focusing geometry, and its sorting in T-junction channels. Three-channel depths (25 μm, 30 μm, and 40 μm) were investigated to study droplet deformation under magnetic forces. Among the three, the 30 μm channel depth showed the most consistent droplet production for the studied range of flow rates. Ferrofluids with different loadings of magnetic nanoparticles were used to observe the behavior for different ratios of magnetic and hydrodynamic forces. Our results show that the effect of these factors on droplet size and generation rate can be tuned and optimized to produce consistent droplet generation and sorting. This approach involves fully coupled magnetic-fluid mechanics models and can predict critical details of the process including droplet size, shape, trajectory, dispensing rate, and the perturbation of the fluid co-flow for different flow rates. The model enables better understanding of the physical phenomena involved in continuous droplet processing and allows efficient parametric analysis and optimization.
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Affiliation(s)
- Venoos Amiri Roodan
- Department of Chemical and Biological Engineering, University at Buffalo, The State University of New York, Buffalo, New York 14260, USA.
| | - Jenifer Gómez-Pastora
- William G. Lowrie Department of Chemical and Biomolecular Engineering, The Ohio State University, 315 Koffolt Laboratories, 151 West Woodruff Avenue, Columbus, Ohio 43210, USA
| | - Ioannis H Karampelas
- Department of Chemical and Biological Engineering, University at Buffalo, The State University of New York, Buffalo, New York 14260, USA.
| | - Cristina González-Fernández
- Department of Chemical and Biomolecular Engineering, ETSIIT, University of Cantabria, Avda. Los Castros s/n, 39005 Santander, Spain
| | - Eugenio Bringas
- Department of Chemical and Biomolecular Engineering, ETSIIT, University of Cantabria, Avda. Los Castros s/n, 39005 Santander, Spain
| | - Inmaculada Ortiz
- Department of Chemical and Biomolecular Engineering, ETSIIT, University of Cantabria, Avda. Los Castros s/n, 39005 Santander, Spain
| | - Jeffrey J Chalmers
- William G. Lowrie Department of Chemical and Biomolecular Engineering, The Ohio State University, 315 Koffolt Laboratories, 151 West Woodruff Avenue, Columbus, Ohio 43210, USA
| | - Edward P Furlani
- Department of Chemical and Biological Engineering, University at Buffalo, The State University of New York, Buffalo, New York 14260, USA. and Department of Electrical Engineering, University at Buffalo, The State University of New York, Buffalo, New York 14260, USA
| | - Mark T Swihart
- Department of Chemical and Biological Engineering, University at Buffalo, The State University of New York, Buffalo, New York 14260, USA.
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Peng H, Zhu M, Gao Z, Liao C, Jia C, Wang H, Zhou H, Zhao J. A centrifugal microfluidic emulsifier integrated with oil storage structures for robust digital LAMP. Biomed Microdevices 2020; 22:18. [DOI: 10.1007/s10544-020-0475-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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9
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Langer K, Joensson HN. Rapid Production and Recovery of Cell Spheroids by Automated Droplet Microfluidics. SLAS Technol 2019; 25:111-122. [PMID: 31561747 DOI: 10.1177/2472630319877376] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The future of the life sciences is linked to automation and microfluidics. As robots start working side by side with scientists, robotic automation of microfluidics in general, and droplet microfluidics in particular, will significantly extend and accelerate the life sciences. Here, we demonstrate the automation of droplet microfluidics using an inexpensive liquid-handling robot to produce human scaffold-free cell spheroids at high throughput. We use pipette actuation and interface the pipetting tip with a droplet-generating microfluidic device. In this device, we produce highly monodisperse droplets with a diameter coefficient of variation (CV) lower than 2%. By encapsulating cells in these droplets, we produce cell spheroids in droplets and recover them to standard labware containers at a throughput of 85,000 spheroids per microfluidic circuit per hour. The viability of the cells in spheroids remains high throughout the process and decreases by >10% (depending on the cell line used) after a 16 h incubation period in nanoliter droplets and automated recovery. Scaffold-free cell spheroids and 3D tissue constructs recapitulate many aspects of functional human tissue more accurately than 2D or single-cell cultures, but assembly methods for spheroids (e.g., hanging drop microplates) have limited throughput. The increased throughput and decreased cost of our method enable spheroid production at the scale needed for lead discovery drug screening, and approach the cost at which these microtissues could be used as building blocks for organ-scale regenerative medicine.
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Affiliation(s)
- Krzysztof Langer
- Division of Protein Science, KTH Royal Institute of Technology, Stockholm, Sweden
| | - Haakan N Joensson
- Division of Protein Science, KTH Royal Institute of Technology, Stockholm, Sweden.,Novo Nordisk Foundation Center for Biosustainability at KTH, Stockholm, Sweden
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10
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Ji X, Zhou T, Deng Y, Shi L, Zhang X, Woo Joo S. A new droplet breakup phenomenon in electrokinetic flow through a microchannel constriction. Electrophoresis 2019; 41:758-760. [PMID: 31177552 DOI: 10.1002/elps.201900140] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2019] [Revised: 05/17/2019] [Accepted: 05/31/2019] [Indexed: 11/07/2022]
Abstract
A completely new droplet breakup phenomenon is reported for droplets passing through a constriction in an electrokinetic flow. The breakup occurs during the droplet shape recovery process past the constriction throat by the interplay of the dielectrophoretic stress release and the interface energy for droplets with smaller permittivity than that of the ambient fluid. There are conditions for constriction ratios and droplet size that the droplet breakup occurs. The numerical predictions provided here require experimental verification, and then can give rise to a novel microfluidic device design with novel droplet manipulations.
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Affiliation(s)
- Xiang Ji
- Mechanical and Electrical Engineering College, Hainan University, Haikou, Hainan, P. R. China
| | - Teng Zhou
- Mechanical and Electrical Engineering College, Hainan University, Haikou, Hainan, P. R. China
| | - Yongbo Deng
- Changchun Institute of Optics, Fine Mechanics and Physics (CIOMP), Chinese Academy of Science, Changchun, Jilin, P. R. China
| | - Liuyong Shi
- Mechanical and Electrical Engineering College, Hainan University, Haikou, Hainan, P. R. China
| | - Xianman Zhang
- Mechanical and Electrical Engineering College, Hainan University, Haikou, Hainan, P. R. China
| | - Sang Woo Joo
- School of Mechanical Engineering, Yeungnam University, Gyongsan, South Korea
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11
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Charon J, Manteca A, Innis CA. Using the Bacterial Ribosome as a Discovery Platform for Peptide-Based Antibiotics. Biochemistry 2019; 58:75-84. [PMID: 30372045 PMCID: PMC7615898 DOI: 10.1021/acs.biochem.8b00927] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
The threat of bacteria resistant to multiple antibiotics poses a major public health problem requiring immediate and coordinated action worldwide. While infectious pathogens have become increasingly resistant to commercially available drugs, antibiotic discovery programs in major pharmaceutical companies have produced no new antibiotic scaffolds in 40 years. As a result, new strategies must be sought to obtain a steady supply of novel scaffolds capable of countering the spread of resistance. The bacterial ribosome is a major target for antimicrobials and is inhibited by more than half of the antibiotics used today. Recent studies showing that the ribosome is a target for several classes of ribosomally synthesized antimicrobial peptides point to ribosome-targeting peptides as a promising source of antibiotic scaffolds. In this Perspective, we revisit the current paradigm of antibiotic discovery by proposing that the bacterial ribosome can be used both as a target and as a tool for the production and selection of peptide-based antimicrobials. Turning the ribosome into a high-throughput platform for the directed evolution of peptide-based antibiotics could be achieved in different ways. One possibility would be to use a combination of state-of-the-art microfluidics and genetic reprogramming techniques, which we will review briefly. If it is successful, this strategy has the potential to produce new classes of antibiotics for treating multi-drug-resistant pathogens.
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Affiliation(s)
- Justine Charon
- Institut Européen de Chimie et Biologie, Univ. Bordeaux, Institut National de la Santé et de la Recherche Médicale (U1212) and Centre National de la Recherche Scientifique (UMR 5320), Pessac 33607, France
| | - Aitor Manteca
- Institut Européen de Chimie et Biologie, Univ. Bordeaux, Institut National de la Santé et de la Recherche Médicale (U1212) and Centre National de la Recherche Scientifique (UMR 5320), Pessac 33607, France
| | - C. Axel Innis
- Institut Européen de Chimie et Biologie, Univ. Bordeaux, Institut National de la Santé et de la Recherche Médicale (U1212) and Centre National de la Recherche Scientifique (UMR 5320), Pessac 33607, France
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12
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Bordbar A, Taassob A, Zarnaghsh A, Kamali R. Slug flow in microchannels: Numerical simulation and applications. J IND ENG CHEM 2018. [DOI: 10.1016/j.jiec.2018.01.021] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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13
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Shrirao AB, Fritz Z, Novik EM, Yarmush GM, Schloss RS, Zahn JD, Yarmush ML. Microfluidic flow cytometry: The role of microfabrication methodologies, performance and functional specification. TECHNOLOGY 2018; 6:1-23. [PMID: 29682599 PMCID: PMC5907470 DOI: 10.1142/s2339547818300019] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Flow cytometry is an invaluable tool utilized in modern biomedical research and clinical applications requiring high throughput, high resolution particle analysis for cytometric characterization and/or sorting of cells and particles as well as for analyzing results from immunocytometric assays. In recent years, research has focused on developing microfluidic flow cytometers with the motivation of creating smaller, less expensive, simpler, and more autonomous alternatives to conventional flow cytometers. These devices could ideally be highly portable, easy to operate without extensive user training, and utilized for research purposes and/or point-of-care diagnostics especially in limited resource facilities or locations requiring on-site analyses. However, designing a device that fulfills the criteria of high throughput analysis, automation and portability, while not sacrificing performance is not a trivial matter. This review intends to present the current state of the field and provide considerations for further improvement by focusing on the key design components of microfluidic flow cytometers. The recent innovations in particle focusing and detection strategies are detailed and compared. This review outlines performance matrix parameters of flow cytometers that are interdependent with each other, suggesting trade offs in selection based on the requirements of the applications. The ongoing contribution of microfluidics demonstrates that it is a viable technology to advance the current state of flow cytometry and develop automated, easy to operate and cost-effective flow cytometers.
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Affiliation(s)
- Anil B Shrirao
- Department of Biomedical Engineering, Rutgers University, 599, Taylor Road, Piscataway, NJ 08854
| | - Zachary Fritz
- Department of Biomedical Engineering, Rutgers University, 599, Taylor Road, Piscataway, NJ 08854
| | - Eric M Novik
- Hurel Corporation, 671, Suite B, U.S. Highway 1, North Brunswick, NJ 08902
| | - Gabriel M Yarmush
- Department of Biomedical Engineering, Rutgers University, 599, Taylor Road, Piscataway, NJ 08854
| | - Rene S Schloss
- Department of Biomedical Engineering, Rutgers University, 599, Taylor Road, Piscataway, NJ 08854
| | - Jeffrey D Zahn
- Department of Biomedical Engineering, Rutgers University, 599, Taylor Road, Piscataway, NJ 08854
| | - Martin L Yarmush
- Department of Biomedical Engineering, Rutgers University, 599, Taylor Road, Piscataway, NJ 08854
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14
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Shaikeea AJD, Basu S, Tyagi A, Sharma S, Hans R, Bansal L. Universal representations of evaporation modes in sessile droplets. PLoS One 2017; 12:e0184997. [PMID: 28915263 PMCID: PMC5600401 DOI: 10.1371/journal.pone.0184997] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2017] [Accepted: 09/04/2017] [Indexed: 11/18/2022] Open
Abstract
In this work, we provide a simple method to represent the contact line dynamics of an evaporating sessile droplet. As a droplet evaporates, two distinct contact line dynamics are observed. They are collectively known as modes of evaporation, namely Constant Contact Radius (CCR) and Constant Contact Angle (CCA). Another intermediate mode-Stick-Slide (SS) or mixed mode is also commonly observed. In this article, we are able to provide a graphical representation to these modes (named as MOE plot), which is visually more comprehensive especially for comparative studies. In addition, the method facilitates quantitative estimation for mode of evaporation (named as MOE fraction or MOEf), which doesn't exist in literature. Thus, various substrates can now be compared based on mode of evaporation (or contact line dynamics), which are governed by fluid property and surface characteristics.
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Affiliation(s)
| | - Saptarshi Basu
- Department of Mechanical Engineering, Indian Institute of Science, Bangalore, India
| | - Abhishek Tyagi
- Department of Mechanical Engineering, Indian Institute of Science, Bangalore, India
| | - Saksham Sharma
- Department of Mechanical Engineering, Indian Institute of Science, Bangalore, India
| | - Rishabh Hans
- Department of Mechanical Engineering, Indian Institute of Science, Bangalore, India
| | - Lalit Bansal
- Department of Mechanical Engineering, Indian Institute of Science, Bangalore, India
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15
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Shen F, Li Y, Liu Z, Li X. Study of flow behaviors of droplet merging and splitting in microchannels using Micro-PIV measurement. MICROFLUIDICS AND NANOFLUIDICS 2017; 21:66. [PMID: 28890680 PMCID: PMC5589143 DOI: 10.1007/s10404-017-1902-y] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Droplet merging and splitting are important droplet manipulations in droplet-based microfluidics. However, the fundamental flow behaviors of droplets were not systematically studied. Hence, we designed two different microstructures to achieve droplet merging and splitting respectively, and quantitatively compared different flow dynamics in different microstructures for droplet merging and splitting via micro-particle image velocimetry (micro-PIV) experiments. Some flow phenomena of droplets different from previous studies were observed during merging and splitting using a high-speed microscope. It was also found the obtained instantaneous velocity vector fields of droplets have significant influence on the droplets merging and splitting. For droplet merging, the probability of droplets coalescence (η) in a microgroove is higher (50% < η < 92%) than that in a T-junction microchannel (15% < η < 50%), and the highest coalescence efficiency (η = 92%) comes at the two-phase flow ratio e of 0.42 in the microgroove. Moreover, compared with a cylinder obstacle, Y-junction bifurcation can split droplets more effectively and the droplet flow during splitting is steadier. The results can provide better understanding of droplet behaviors and are useful for the design and applications of droplet-based microfluidics.
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Affiliation(s)
- Feng Shen
- College of Mechanical Engineering and Applied Electronics Technology, Beijing University of Technology, Beijing 100124, China
| | - Yi Li
- College of Mechanical Engineering and Applied Electronics Technology, Beijing University of Technology, Beijing 100124, China
| | - Zhaomiao Liu
- College of Mechanical Engineering and Applied Electronics Technology, Beijing University of Technology, Beijing 100124, China
| | - XiuJun Li
- Department of Chemistry, University of Texas at El Paso, El Paso, TX 79968, USA
- Border Biomedical Research Center, University of Texas at El Paso, El Paso, TX 79968, USA
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16
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Chen YC, Liu K, Shen CKF, van Dam RM. On-demand generation and mixing of liquid-in-gas slugs with digitally-programmable composition and size. JOURNAL OF MICROMECHANICS AND MICROENGINEERING : STRUCTURES, DEVICES, AND SYSTEMS 2015; 25:084006. [PMID: 29167603 PMCID: PMC5695874 DOI: 10.1088/0960-1317/25/8/084006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Microscopic droplets or slugs of mixed reagents provide a convenient platform for performing large numbers of isolated biochemical or chemical reactions for many screening and optimization applications. Myriad microfluidic approaches have emerged for creating droplets or slugs with controllable size and composition, generally using an immiscible carrier fluid to assist with the formation or merging processes. We report a novel device for generation of liquid slugs in air when the use of a carrier liquid is not compatible with the application. The slug generator contains two adjacent chambers, each of which has a volume that can be digitally adjusted by closing selected microvalves. Reagents are filled into the two chambers, merged together into a contiguous liquid slug, ejected at the desired time from the device using gas pressure, and mixed by flowing in a downstream channel. Programmable size and composition of slugs is achieved by dynamically adjusting the volume of each chamber prior to filling. Slug formation in this fashion is independent of fluid properties and can easily be scaled to mix larger numbers of reagents. This device has already been used to screen monomer ratios in supramolecular nanoparticle assembly and radiolabeling conditions of engineered antibodies, and here we provide a detailed description of the underlying device.
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Affiliation(s)
| | | | - Clifton Kwang-Fu Shen
- Department of Molecular & Medical Pharmacology and Crump Institute for Molecular Imaging, David Geffen School of Medicine, University of California, Los Angeles, 570 Westwood Plaza, Los Angeles, CA 90095
| | - R. Michael van Dam
- Department of Molecular & Medical Pharmacology and Crump Institute for Molecular Imaging, David Geffen School of Medicine, University of California, Los Angeles, 570 Westwood Plaza, Los Angeles, CA 90095
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17
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Hayes CJ, Dalton TM. Microfluidic droplet-based PCR instrumentation for high-throughput gene expression profiling and biomarker discovery. BIOMOLECULAR DETECTION AND QUANTIFICATION 2015; 4:22-32. [PMID: 27077035 PMCID: PMC4822205 DOI: 10.1016/j.bdq.2015.04.003] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/09/2015] [Revised: 04/23/2015] [Accepted: 04/24/2015] [Indexed: 01/02/2023]
Abstract
PCR is a common and often indispensable technique used in medical and biological research labs for a variety of applications. Real-time quantitative PCR (RT-qPCR) has become a definitive technique for quantitating differences in gene expression levels between samples. Yet, in spite of this importance, reliable methods to quantitate nucleic acid amounts in a higher throughput remain elusive. In the following paper, a unique design to quantify gene expression levels at the nanoscale in a continuous flow system is presented. Fully automated, high-throughput, low volume amplification of deoxynucleotides (DNA) in a droplet based microfluidic system is described. Unlike some conventional qPCR instrumentation that use integrated fluidic circuits or plate arrays, the instrument performs qPCR in a continuous, micro-droplet flowing process with droplet generation, distinctive reagent mixing, thermal cycling and optical detection platforms all combined on one complete instrument. Detailed experimental profiling of reactions of less than 300 nl total volume is achieved using the platform demonstrating the dynamic range to be 4 order logs and consistent instrument sensitivity. Furthermore, reduced pipetting steps by as much as 90% and a unique degree of hands-free automation makes the analytical possibilities for this instrumentation far reaching. In conclusion, a discussion of the first demonstrations of this approach to perform novel, continuous high-throughput biological screens is presented. The results generated from the instrument, when compared with commercial instrumentation, demonstrate the instrument reliability and robustness to carry out further studies of clinical significance with added throughput and economic benefits.
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Affiliation(s)
- Christopher J Hayes
- Stokes Institute, Department of Mechanical, Aeronautical and Biomedical Engineering, University of Limerick, Limerick, Ireland; Department of Life Sciences, University of Limerick, Limerick, Ireland
| | - Tara M Dalton
- Stokes Institute, Department of Mechanical, Aeronautical and Biomedical Engineering, University of Limerick, Limerick, Ireland
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18
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Huang HY, Shen HH, Tien CH, Li CJ, Fan SK, Liu CH, Hsu WS, Yao DJ. Digital Microfluidic Dynamic Culture of Mammalian Embryos on an Electrowetting on Dielectric (EWOD) Chip. PLoS One 2015; 10:e0124196. [PMID: 25933003 PMCID: PMC4416819 DOI: 10.1371/journal.pone.0124196] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2014] [Accepted: 02/26/2015] [Indexed: 01/04/2023] Open
Abstract
Current human fertilization in vitro (IVF) bypasses the female oviduct and manually inseminates, fertilizes and cultivates embryos in a static microdrop containing appropriate chemical compounds. A microfluidic microchannel system for IVF is considered to provide an improved in-vivo-mimicking environment to enhance the development in a culture system for an embryo before implantation. We demonstrate a novel digitalized microfluidic device powered with electrowetting on a dielectric (EWOD) to culture an embryo in vitro in a single droplet in a microfluidic environment to mimic the environment in vivo for development of the embryo and to culture the embryos with good development and live births. Our results show that the dynamic culture powered with EWOD can manipulate a single droplet containing one mouse embryo and culture to the blastocyst stage. The rate of embryo cleavage to a hatching blastocyst with a dynamic culture is significantly greater than that with a traditional static culture (p<0.05). The EWOD chip enhances the culture of mouse embryos in a dynamic environment. To test the reproductive outcome of the embryos collected from an EWOD chip as a culture system, we transferred embryos to pseudo-pregnant female mice and produced live births. These results demonstrate that an EWOD-based microfluidic device is capable of culturing mammalian embryos in a microfluidic biological manner, presaging future clinical application.
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Affiliation(s)
- Hong-Yuan Huang
- Department of Obstetrics and Gynecology, Linkou Medical Center, Chang Gung Memorial Hospital, Taoyuan, Taiwan
- Department of Obstetrics and Gynecology, Chang Gung University and College of Medicine, Taoyuan, Taiwan
| | - Hsien-Hua Shen
- Institute of Nanoengineering and Microsystem, National Tsing Hua University, Hsinchu, Taiwan
| | - Chang-Hung Tien
- Department of Mechanical Engineering, National Taiwan University, Taipei, Taiwan
| | - Chin-Jung Li
- Department of Obstetrics and Gynecology, Linkou Medical Center, Chang Gung Memorial Hospital, Taoyuan, Taiwan
| | - Shih-Kang Fan
- Department of Mechanical Engineering, National Taiwan University, Taipei, Taiwan
| | - Cheng-Hsien Liu
- Department of Power Mechanical Engineering, National Tsing Hua University, Hsinchu, Taiwan
| | - Wen-Syang Hsu
- Department of Mechanical Engineering, National Chiao Tung University, Hsinchu, Taiwan
| | - Da-Jeng Yao
- Institute of Nanoengineering and Microsystem, National Tsing Hua University, Hsinchu, Taiwan
- Department of Power Mechanical Engineering, National Tsing Hua University, Hsinchu, Taiwan
- * E-mail:
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19
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Abstract
Contact-angle hysteresis of a liquid suspended on surface microstructures, namely in a Cassie-Baxter state, is determined mainly by the receding contact line although not fully understood. Existing modified Cassie-Baxter models predict some but not most experimental data in the literature. Noting that most models were based on the two-dimensional (2-D) principle whereas the experiments were under three-dimensional (3-D) conditions, here we develop a 2-D experiment. While 3-D experiments measure the receding contact lines averaged over space and time, 2-D experiments eliminate the spatial averaging and can further eliminate the temporal averaging by high-speed visualization. The resulting details of the contact line motion lead us to propose a 2-D model, which incorporates the contact-line friction. The new 2-D model matches the 2-D experimental results excellently while all existing models show significant deviation. By introducing a line solid fraction term, the 2-D model is further generalized to a 3-D model, which successfully predicts a wide range of 3-D data in the literature regardless of their distinct microstructures and receding modes.
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Affiliation(s)
- Tingyi Leo Liu
- Mechanical and Aerospace Engineering Department, University of California, Los Angeles, California 90095, USA.
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20
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Tarameshlou M, Jafari SH, Rezaeian I, Khonakdar HA. A Microfluidic Approach to Synthesize Monodisperse Poly (2-Hydroxyethyl Methacrylate) Based Spherical Microgels via Water in Water Emulsion Technique. INT J POLYM MATER PO 2014. [DOI: 10.1080/00914037.2014.886225] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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