1
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Fedosov DA, Gompper G. Cells on a string: Characterizing cellular structure and dynamics through viscoelastic phenotyping. Biophys J 2024; 123:757-758. [PMID: 38419329 PMCID: PMC10995419 DOI: 10.1016/j.bpj.2024.02.027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2024] [Revised: 02/26/2024] [Accepted: 02/26/2024] [Indexed: 03/02/2024] Open
Affiliation(s)
- Dmitry A Fedosov
- Theoretical Physics of Living Matter, Institute for Advanced Simulation, Forschungszentrum Jülich, Jülich, Germany
| | - Gerhard Gompper
- Theoretical Physics of Living Matter, Institute for Advanced Simulation, Forschungszentrum Jülich, Jülich, Germany.
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2
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Gironella-Torrent M, Bergamaschi G, Sorkin R, Wuite GJL, Ritort F. Viscoelastic phenotyping of red blood cells. Biophys J 2024; 123:770-781. [PMID: 38268191 PMCID: PMC10995428 DOI: 10.1016/j.bpj.2024.01.019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2023] [Revised: 12/21/2023] [Accepted: 01/18/2024] [Indexed: 01/26/2024] Open
Abstract
Red blood cells (RBCs) are the simplest cell types with complex dynamical and viscoelastic phenomenology. While the mechanical rigidity and the flickering noise of RBCs have been extensively investigated, an accurate determination of the constitutive equations of the relaxational kinetics is lacking. Here we measure the force relaxation of RBCs under different types of tensional and compressive extension-jump protocols by attaching an optically trapped bead to the RBC membrane. Relaxational kinetics follows linear response from 60 pN (tensional) to -20 pN (compressive) applied forces, exhibiting a triple exponential function with three well-separated timescales over four decades (0.01-100 s). While the fast timescale (τF∼0.02(1)s) corresponds to the relaxation of the membrane, the intermediate and slow timescales (τI=4(1)s; τS=70(8)s) likely arise from the cortex dynamics and the cytosol viscosity. Relaxation is highly heterogeneous across the RBC population, yet the three relaxation times are correlated, showing dynamical scaling. Finally, we find that glucose depletion and laser illumination of RBCs lead to faster triple exponential kinetics and RBC rigidification. Viscoelastic phenotyping is a promising dynamical biomarker applicable to other cell types and active systems.
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Affiliation(s)
- Marta Gironella-Torrent
- Small Biosystems Lab, Condensed Matter Physics Department, University of Barcelona, Barcelona, Spain; Department of Medical Biochemistry and Cell Biology, Institute of Biomedicine, The Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.
| | - Giulia Bergamaschi
- Department of Physics and Astronomy and LaserLab, Vrije Universiteit Amsterdam, Amsterdam, the Netherlands
| | - Raya Sorkin
- Raymond and Beverly Sackler Faculty of Exact Sciences, School of Chemistry, Tel Aviv University, Tel Aviv, Israel
| | - Gijs J L Wuite
- Department of Physics and Astronomy and LaserLab, Vrije Universiteit Amsterdam, Amsterdam, the Netherlands
| | - Felix Ritort
- Small Biosystems Lab, Condensed Matter Physics Department, University of Barcelona, Barcelona, Spain; Institut de Nanociència i Nanotecnologia (IN2UB), Universitat de Barcelona, Barcelona, Spain
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3
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Nouaman M, Darras A, Wagner C, Recktenwald SM. Confinement effect on the microcapillary flow and shape of red blood cells. BIOMICROFLUIDICS 2024; 18:024104. [PMID: 38577010 PMCID: PMC10994673 DOI: 10.1063/5.0197208] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/12/2024] [Accepted: 03/14/2024] [Indexed: 04/06/2024]
Abstract
The ability to change shape is essential for the proper functioning of red blood cells (RBCs) within the microvasculature. The shape of RBCs significantly influences blood flow and has been employed in microfluidic lab-on-a-chip devices, serving as a diagnostic biomarker for specific pathologies and enabling the assessment of RBC deformability. While external flow conditions, such as the vessel size and the flow velocity, are known to impact microscale RBC flow, our comprehensive understanding of how their shape-adapting ability is influenced by channel confinement in biomedical applications remains incomplete. This study explores the impact of various rectangular and square channels, each with different confinement and aspect ratios, on the in vitro RBC flow behavior and characteristic shapes. We demonstrate that rectangular microchannels, with a height similar to the RBC diameter in combination with a confinement ratio exceeding 0.9, are required to generate distinctive well-defined croissant and slipper-like RBC shapes. These shapes are characterized by their equilibrium positions in the channel cross section, and we observe a strong elongation of both stable shapes in response to the shear rate across the different channels. Less confined channel configurations lead to the emergence of unstable other shape types that display rich shape dynamics. Our work establishes an experimental framework to understand the influence of channel size on the single-cell flow behavior of RBCs, providing valuable insights for the design of biomicrofluidic single-cell analysis applications.
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Affiliation(s)
- Mohammed Nouaman
- Dynamics of Fluids, Department of Experimental Physics, Saarland University, 66123 Saarbrücken, Germany
| | - Alexis Darras
- Dynamics of Fluids, Department of Experimental Physics, Saarland University, 66123 Saarbrücken, Germany
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4
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Cheng X, Caruso C, Lam WA, Graham MD. Marginated aberrant red blood cells induce pathologic vascular stress fluctuations in a computational model of hematologic disorders. SCIENCE ADVANCES 2023; 9:eadj6423. [PMID: 38019922 PMCID: PMC10686556 DOI: 10.1126/sciadv.adj6423] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/10/2023] [Accepted: 10/27/2023] [Indexed: 12/01/2023]
Abstract
Red blood cell (RBC) disorders such as sickle cell disease affect billions worldwide. While much attention focuses on altered properties of aberrant RBCs and corresponding hemodynamic changes, RBC disorders are also associated with vascular dysfunction, whose origin remains unclear and which provoke severe consequences including stroke. Little research has explored whether biophysical alterations of RBCs affect vascular function. We use a detailed computational model of blood that enables characterization of cell distributions and vascular stresses in blood disorders and compare simulation results with experimental observations. Aberrant RBCs, with their smaller size and higher stiffness, concentrate near vessel walls (marginate) because of contrasts in physical properties relative to normal cells. In a curved channel exemplifying the geometric complexity of the microcirculation, these cells distribute heterogeneously, indicating the importance of geometry. Marginated cells generate large transient stress fluctuations on vessel walls, indicating a mechanism for the observed vascular inflammation.
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Affiliation(s)
- Xiaopo Cheng
- Department of Chemical and Biological Engineering, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Christina Caruso
- Aflac Cancer and Blood Disorders Center of Children’s Healthcare of Atlanta, Department of Pediatrics, Emory University School of Medicine, Atlanta, GA 30307, USA
| | - Wilbur A. Lam
- Aflac Cancer and Blood Disorders Center of Children’s Healthcare of Atlanta, Department of Pediatrics, Emory University School of Medicine, Atlanta, GA 30307, USA
- Wallace H. Coulter Department of Biomedical Engineering. Georgia Institute of Technology and Emory University, Atlanta, GA 30332, USA
| | - Michael D. Graham
- Department of Chemical and Biological Engineering, University of Wisconsin-Madison, Madison, WI 53706, USA
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5
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Bureau L, Coupier G, Salez T. Lift at low Reynolds number. THE EUROPEAN PHYSICAL JOURNAL. E, SOFT MATTER 2023; 46:111. [PMID: 37957450 DOI: 10.1140/epje/s10189-023-00369-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/14/2023] [Accepted: 10/19/2023] [Indexed: 11/15/2023]
Abstract
Lift forces are widespread in hydrodynamics. These are typically observed for big and fast objects and are often associated with a combination of fluid inertia (i.e. large Reynolds numbers) and specific symmetry-breaking mechanisms. In contrast, the properties of viscosity-dominated (i.e. low Reynolds numbers) flows make it more difficult for such lift forces to emerge. However, the inclusion of boundary effects qualitatively changes this picture. Indeed, in the context of soft and biological matter, recent studies have revealed the emergence of novel lift forces generated by boundary softness, flow gradients and/or surface charges. The aim of the present review is to gather and analyse this corpus of literature, in order to identify and unify the questioning within the associated communities, and pave the way towards future research.
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Affiliation(s)
- Lionel Bureau
- Univ. Grenoble Alpes, CNRS, LIPhy, 38000, Grenoble, France.
| | | | - Thomas Salez
- Univ. Bordeaux, CNRS, LOMA, UMR 5798, 33400, Talence, France.
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6
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Liu Y, Yao X, Fan C, Zhang G, Luo X, Qian Y. Microfabrication and lab-on-a-chip devices promote in vitromodeling of neural interfaces for neuroscience researches and preclinical applications. Biofabrication 2023; 16:012002. [PMID: 37832555 DOI: 10.1088/1758-5090/ad032a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2022] [Accepted: 10/13/2023] [Indexed: 10/15/2023]
Abstract
Neural tissues react to injuries through the orchestration of cellular reprogramming, generating specialized cells and activating gene expression that helps with tissue remodeling and homeostasis. Simplified biomimetic models are encouraged to amplify the physiological and morphological changes during neural regeneration at cellular and molecular levels. Recent years have witnessed growing interest in lab-on-a-chip technologies for the fabrication of neural interfaces. Neural system-on-a-chip devices are promisingin vitromicrophysiological platforms that replicate the key structural and functional characteristics of neural tissues. Microfluidics and microelectrode arrays are two fundamental techniques that are leveraged to address the need for microfabricated neural devices. In this review, we explore the innovative fabrication, mechano-physiological parameters, spatiotemporal control of neural cell cultures and chip-based neurogenesis. Although the high variability in different constructs, and the restriction in experimental and analytical access limit the real-life applications of microphysiological models, neural system-on-a-chip devices have gained considerable translatability for modeling neuropathies, drug screening and personalized therapy.
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Affiliation(s)
- Yang Liu
- Department of Orthopedics, Shanghai Sixth People's Hospital affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai 200233, People's Republic of China
- Shanghai Engineering Research Center for Orthopaedic Material Innovation and Tissue Regeneration, Shanghai 200233, People's Republic of China
- State Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, People's Republic of China
- Key Laboratory of Biopharmaceutical Preparation and Delivery, Chinese Academy of Sciences, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, People's Republic of China
| | - Xiangyun Yao
- Department of Orthopedics, Shanghai Sixth People's Hospital affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai 200233, People's Republic of China
- Shanghai Engineering Research Center for Orthopaedic Material Innovation and Tissue Regeneration, Shanghai 200233, People's Republic of China
| | - Cunyi Fan
- Department of Orthopedics, Shanghai Sixth People's Hospital affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai 200233, People's Republic of China
- Shanghai Engineering Research Center for Orthopaedic Material Innovation and Tissue Regeneration, Shanghai 200233, People's Republic of China
| | - Guifeng Zhang
- State Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, People's Republic of China
- Key Laboratory of Biopharmaceutical Preparation and Delivery, Chinese Academy of Sciences, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, People's Republic of China
| | - Xi Luo
- State Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, People's Republic of China
- Key Laboratory of Biopharmaceutical Preparation and Delivery, Chinese Academy of Sciences, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, People's Republic of China
| | - Yun Qian
- Department of Orthopedics, Shanghai Sixth People's Hospital affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai 200233, People's Republic of China
- Shanghai Engineering Research Center for Orthopaedic Material Innovation and Tissue Regeneration, Shanghai 200233, People's Republic of China
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7
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Akerkouch L, Le T. Shape Transitions of Red Blood Cell under Oscillatory Flows in Microchannels. RESEARCH SQUARE 2023:rs.3.rs-3296659. [PMID: 37693621 PMCID: PMC10491371 DOI: 10.21203/rs.3.rs-3296659/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/12/2023]
Abstract
This paper aims to examine the ability to control Red Blood Cell (RBCs) dynamics and the associated extracellular flow patterns in microfluidic channels via oscillatory flows. Our computational approach employs a hybrid continuum-particle coupling, in which the cell membrane and cytosol fluid are modeled using the Dissipative Particle Dynamics (DPD) method. The blood plasma is modeled as an incompressible fluid via the Immersed Boundary Method (IBM). This coupling is novel because it provides an accurate description of RBC dynamics while the extracellular flow patterns around the RBCs are also captured in detail. Our coupling methodology is validated with available experimental and computational data in the literature and shows excellent agreement. We explore the controlling regimes by varying the shape of the oscillatory flow waveform at the channel inlet. Our simulation results show that a host of RBC morphological dynamics emerges depending on the channel geometry, the incoming flow waveform, and the RBC initial location. Complex dynamics of RBC are induced by the flow waveform. Our results show that the RBC shape is strongly dependent on its initial location. Our results suggest that the controlling of oscillatory flows can be used to induce specific morphological shapes of RBCs and the surrounding fluid patterns in bio-engineering applications.
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Affiliation(s)
- Lahcen Akerkouch
- Department of Civil, Construction, and Environmental Engineering, North Dakota State University, 1410 14th N, Fargo, 58102, ND, USA
| | - Trung Le
- Department of Civil, Construction, and Environmental Engineering, North Dakota State University, 1410 14th N, Fargo, 58102, ND, USA
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8
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Amoudruz L, Economides A, Arampatzis G, Koumoutsakos P. The stress-free state of human erythrocytes: Data-driven inference of a transferable RBC model. Biophys J 2023; 122:1517-1525. [PMID: 36926695 PMCID: PMC10147838 DOI: 10.1016/j.bpj.2023.03.019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2022] [Revised: 12/19/2022] [Accepted: 03/10/2023] [Indexed: 03/17/2023] Open
Abstract
The stress-free state (SFS) of red blood cells (RBCs) is a fundamental reference configuration for the calibration of computational models, yet it remains unknown. Current experimental methods cannot measure the SFS of cells without affecting their mechanical properties, whereas computational postulates are the subject of controversial discussions. Here, we introduce data-driven estimates of the SFS shape and the visco-elastic properties of RBCs. We employ data from single-cell experiments that include measurements of the equilibrium shape of stretched cells and relaxation times of initially stretched RBCs. A hierarchical Bayesian model accounts for these experimental and data heterogeneities. We quantify, for the first time, the SFS of RBCs and use it to introduce a transferable RBC (t-RBC) model. The effectiveness of the proposed model is shown on predictions of unseen experimental conditions during the inference, including the critical stress of transitions between tumbling and tank-treading cells in shear flow. Our findings demonstrate that the proposed t-RBC model provides predictions of blood flows with unprecedented accuracy and quantified uncertainties.
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Affiliation(s)
- Lucas Amoudruz
- Computational Science and Engineering Laboratory, ETH Zürich, Zürich, Switzerland; School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts
| | - Athena Economides
- Computational Science and Engineering Laboratory, ETH Zürich, Zürich, Switzerland; School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts
| | - Georgios Arampatzis
- Computational Science and Engineering Laboratory, ETH Zürich, Zürich, Switzerland; School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts
| | - Petros Koumoutsakos
- Computational Science and Engineering Laboratory, ETH Zürich, Zürich, Switzerland; School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts.
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9
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Kabacaoğlu G, Lushi E. Cross-stream migration of a vesicle in vortical flows. Phys Rev E 2023; 107:044608. [PMID: 37198778 DOI: 10.1103/physreve.107.044608] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2022] [Accepted: 04/03/2023] [Indexed: 05/19/2023]
Abstract
We use numerical simulations to systematically investigate the vesicle dynamics in two-dimensional (2D) Taylor-Green vortex flow in the absence of inertial forces. Vesicles are highly deformable membranes encapsulating an incompressible fluid and they serve as numerical and experimental proxies for biological cells such as red blood cells. Vesicle dynamics has been studied in free-space or bounded shear, Poiseuille, and Taylor-Couette flows in 2D and 3D. Taylor-Green vortex are characterized with even more complicated properties than those flows such as nonuniform flow line curvature, shear gradient. We study the effects of two parameters on the vesicle dynamics: the ratio of the interior fluid viscosity to that of the exterior one and the ratio of the shear forces on the vesicle to the membrane stiffness (characterized by the capillary number). Vesicle deformability nonlinearly depends on these parameters. Although the study is in 2D, our findings contribute to the wide spectrum of intriguing vesicle dynamics: Vesicles migrate inwards and eventually rotate at the vortex center if they are sufficiently deformable. If not, then they migrate away from the vortex center and travel across the periodic arrays of vortices. The outward migration of a vesicle is a new phenomenon in Taylor-Green vortex flow and has not been observed in any other flows so far. Such cross-streamline migration of deformable particles can be utilized in several applications such as microfluidics for cell separation.
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Affiliation(s)
- Gökberk Kabacaoğlu
- Department of Mechanical Engineering, İhsan Doğramacı Bilkent University Ankara, 06800, Turkey
| | - Enkeleida Lushi
- Department of Mathematical Sciences, New Jersey Institute of Technology Newark, New Jersey 07102, USA
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10
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Salipante PF. Microfluidic techniques for mechanical measurements of biological samples. BIOPHYSICS REVIEWS 2023; 4:011303. [PMID: 38505816 PMCID: PMC10903441 DOI: 10.1063/5.0130762] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2022] [Accepted: 12/30/2022] [Indexed: 03/21/2024]
Abstract
The use of microfluidics to make mechanical property measurements is increasingly common. Fabrication of microfluidic devices has enabled various types of flow control and sensor integration at micrometer length scales to interrogate biological materials. For rheological measurements of biofluids, the small length scales are well suited to reach high rates, and measurements can be made on droplet-sized samples. The control of flow fields, constrictions, and external fields can be used in microfluidics to make mechanical measurements of individual bioparticle properties, often at high sampling rates for high-throughput measurements. Microfluidics also enables the measurement of bio-surfaces, such as the elasticity and permeability properties of layers of cells cultured in microfluidic devices. Recent progress on these topics is reviewed, and future directions are discussed.
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Affiliation(s)
- Paul F. Salipante
- National Institute of Standards and Technology, Polymers and Complex Fluids Group, Gaithersburg, Maryland 20899, USA
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11
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Grigorev GV, Lebedev AV, Wang X, Qian X, Maksimov GV, Lin L. Advances in Microfluidics for Single Red Blood Cell Analysis. BIOSENSORS 2023; 13:117. [PMID: 36671952 PMCID: PMC9856164 DOI: 10.3390/bios13010117] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Revised: 12/04/2022] [Accepted: 12/23/2022] [Indexed: 05/24/2023]
Abstract
The utilizations of microfluidic chips for single RBC (red blood cell) studies have attracted great interests in recent years to filter, trap, analyze, and release single erythrocytes for various applications. Researchers in this field have highlighted the vast potential in developing micro devices for industrial and academia usages, including lab-on-a-chip and organ-on-a-chip systems. This article critically reviews the current state-of-the-art and recent advances of microfluidics for single RBC analyses, including integrated sensors and microfluidic platforms for microscopic/tomographic/spectroscopic single RBC analyses, trapping arrays (including bifurcating channels), dielectrophoretic and agglutination/aggregation studies, as well as clinical implications covering cancer, sepsis, prenatal, and Sickle Cell diseases. Microfluidics based RBC microarrays, sorting/counting and trapping techniques (including acoustic, dielectrophoretic, hydrodynamic, magnetic, and optical techniques) are also reviewed. Lastly, organs on chips, multi-organ chips, and drug discovery involving single RBC are described. The limitations and drawbacks of each technology are addressed and future prospects are discussed.
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Affiliation(s)
- Georgii V. Grigorev
- Data Science and Information Technology Research Center, Tsinghua Berkeley Shenzhen Institute, Tsinghua University, Shenzhen 518055, China
- Mechanical Engineering Department, University of California in Berkeley, Berkeley, CA 94720, USA
- School of Information Technology, Cherepovets State University, 162600 Cherepovets, Russia
| | - Alexander V. Lebedev
- Machine Building Department, Bauman Moscow State University, 105005 Moscow, Russia
| | - Xiaohao Wang
- Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, China
| | - Xiang Qian
- Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, China
| | - George V. Maksimov
- Faculty of Biology, Lomonosov Moscow State University, 119991 Moscow, Russia
- Physical metallurgy Department, Federal State Autonomous Educational Institution of Higher Education National Research Technological University “MISiS”, 119049 Moscow, Russia
| | - Liwei Lin
- Mechanical Engineering Department, University of California in Berkeley, Berkeley, CA 94720, USA
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12
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Kim H, Zhbanov A, Yang S. Microfluidic Systems for Blood and Blood Cell Characterization. BIOSENSORS 2022; 13:13. [PMID: 36671848 PMCID: PMC9856090 DOI: 10.3390/bios13010013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/24/2022] [Revised: 12/16/2022] [Accepted: 12/19/2022] [Indexed: 06/17/2023]
Abstract
A laboratory blood test is vital for assessing a patient's health and disease status. Advances in microfluidic technology have opened the door for on-chip blood analysis. Currently, microfluidic devices can reproduce myriad routine laboratory blood tests. Considerable progress has been made in microfluidic cytometry, blood cell separation, and characterization. Along with the usual clinical parameters, microfluidics makes it possible to determine the physical properties of blood and blood cells. We review recent advances in microfluidic systems for measuring the physical properties and biophysical characteristics of blood and blood cells. Added emphasis is placed on multifunctional platforms that combine several microfluidic technologies for effective cell characterization. The combination of hydrodynamic, optical, electromagnetic, and/or acoustic methods in a microfluidic device facilitates the precise determination of various physical properties of blood and blood cells. We analyzed the physical quantities that are measured by microfluidic devices and the parameters that are determined through these measurements. We discuss unexplored problems and present our perspectives on the long-term challenges and trends associated with the application of microfluidics in clinical laboratories. We expect the characterization of the physical properties of blood and blood cells in a microfluidic environment to be considered a standard blood test in the future.
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Affiliation(s)
- Hojin Kim
- Department of Mechatronics Engineering, Dongseo University, Busan 47011, Republic of Korea
| | - Alexander Zhbanov
- School of Mechanical Engineering, Gwangju Institute of Science and Technology (GIST), Gwangju 61005, Republic of Korea
| | - Sung Yang
- School of Mechanical Engineering, Gwangju Institute of Science and Technology (GIST), Gwangju 61005, Republic of Korea
- Department of Biomedical Science and Engineering, Gwangju Institute of Science and Technology (GIST), Gwangju 61005, Republic of Korea
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13
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Feng H, Patel D, Magda JJ, Geher S, Sigala PA, Gale BK. Multiple-Streams Focusing-Based Cell Separation in High Viscoelasticity Flow. ACS OMEGA 2022; 7:41759-41767. [PMID: 36406492 PMCID: PMC9670260 DOI: 10.1021/acsomega.2c06021] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/17/2022] [Accepted: 10/25/2022] [Indexed: 06/16/2023]
Abstract
Viscoelastic flow has been widely used in microfluidic particle separation processes, in which particles get focused on the channel center in diluted viscoelastic flow. In this paper, the transition from single-stream focusing to multiple-streams focusing (MSF) in high viscoelastic flow is observed, which is applied for cell separation processes. Particle focusing stream bifurcation is caused by the balance between elastic force and viscoelastic secondary flow drag force. The influence of cell physical properties, such as cell dimension, shape, and deformability, on the formation of multiple-streams focusing is studied in detail. Particle separation is realized utilizing different separation criteria. The size-based separation of red (RBC) and white (WBC) blood cells is demonstrated in which cells get focused in different streams based on their dimension difference. Cells with different deformabilities get stretched in the viscoelastic flow, leading to the change of focusing streams, and this property is harnessed to separate red blood cells infected with the malaria parasite, Plasmodium falciparum. The achieved results promote our understanding of particle movement in the high viscoelastic flow and enable new particle manipulation and separation processes for sample treatment in biofluids.
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Affiliation(s)
- Haidong Feng
- Department
of Mechanical Engineering, University of
Utah, Salt Lake
City, Utah84112, United States
- Department
of Biological Engineering, Massachusetts
Institute of Technology, Cambridge, Massachusetts02139, United States
| | - Dhruv Patel
- Department
of Mechanical Engineering, University of
Utah, Salt Lake
City, Utah84112, United States
| | - Jules J. Magda
- Department
of Chemical Engineering, University of Utah, Salt Lake City, Utah84112, United States
| | - Sage Geher
- Department
of Biochemistry, University of Utah School
of Medicine, Salt Lake City, Utah84112, United States
| | - Paul A. Sigala
- Department
of Biochemistry, University of Utah School
of Medicine, Salt Lake City, Utah84112, United States
| | - Bruce K. Gale
- Department
of Mechanical Engineering, University of
Utah, Salt Lake
City, Utah84112, United States
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14
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Unsteady Dynamics of Vesicles in a Confined Poiseuille Flow. CHINESE JOURNAL OF POLYMER SCIENCE 2022. [DOI: 10.1007/s10118-022-2774-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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15
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Fischer TM. The Shape of Human Red Blood Cells Suspended in Autologous Plasma and Serum. Cells 2022; 11:cells11121941. [PMID: 35741070 PMCID: PMC9222013 DOI: 10.3390/cells11121941] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2022] [Revised: 06/10/2022] [Accepted: 06/13/2022] [Indexed: 01/27/2023] Open
Abstract
(1) Background: In almost all studies of the shape of the human red blood cell (RBC), the suspending medium was a salt solution supplemented with albumin. However, the ratio of thickness across the dimple region to the thickness of the rim (THR) depends on the albumin concentration. Values of the THR in the literature range from 0.27 to 0.627 whereas in the present work it was 0.550 or 0.601 whether measured in plasma or serum. (2) Methods: 9911 RBCs of eight donors were suspended in autologous plasma or serum. Sedimented RBCs were observed under bright field illumination at 416 nm. From the profiles of gray value, the THR was determined. (3) Results: The THR displays a wide distribution within a single blood sample. A direct correlation of THR and spontaneous curvature of the membrane is likely. The variation of the mean THR between different donors is large. The aspect ratio of RBCs viewed face-on ranged on average from 1 to 1.48. In oval RBCs, the rim is thicker along the major axis than along the minor axis, an effect increasing with increasing aspect ratio. Remodeling of the membrane skeleton occurs in vivo with a characteristic time (τ) on the order of 1 h. (4) Conclusions: Consideration of these data in models of RBC behavior might improve the agreement with observations. τ≈1 h suggests a more general type of reference configuration of the membrane skeleton than a stress free shape.
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Affiliation(s)
- Thomas M. Fischer
- Department of Experimental Physics, Saarland University, Campus E2 6, 66123 Saarbrücken, Germany; ; Tel.: +49-160-2293318
- Laboratory for Red Cell Rheology, Krummer Weg 20, 52134 Herzogenrath, Germany
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16
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Recktenwald SM, Lopes MGM, Peter S, Hof S, Simionato G, Peikert K, Hermann A, Danek A, van Bentum K, Eichler H, Wagner C, Quint S, Kaestner L. Erysense, a Lab-on-a-Chip-Based Point-of-Care Device to Evaluate Red Blood Cell Flow Properties With Multiple Clinical Applications. Front Physiol 2022; 13:884690. [PMID: 35574449 PMCID: PMC9091344 DOI: 10.3389/fphys.2022.884690] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2022] [Accepted: 04/11/2022] [Indexed: 11/18/2022] Open
Abstract
In many medical disciplines, red blood cells are discovered to be biomarkers since they "experience" various conditions in basically all organs of the body. Classical examples are diabetes and hypercholesterolemia. However, recently the red blood cell distribution width (RDW), is often referred to, as an unspecific parameter/marker (e.g., for cardiac events or in oncological studies). The measurement of RDW requires venous blood samples to perform the complete blood cell count (CBC). Here, we introduce Erysense, a lab-on-a-chip-based point-of-care device, to evaluate red blood cell flow properties. The capillary chip technology in combination with algorithms based on artificial neural networks allows the detection of very subtle changes in the red blood cell morphology. This flow-based method closely resembles in vivo conditions and blood sample volumes in the sub-microliter range are sufficient. We provide clinical examples for potential applications of Erysense as a diagnostic tool [here: neuroacanthocytosis syndromes (NAS)] and as cellular quality control for red blood cells [here: hemodiafiltration (HDF) and erythrocyte concentrate (EC) storage]. Due to the wide range of the applicable flow velocities (0.1-10 mm/s) different mechanical properties of the red blood cells can be addressed with Erysense providing the opportunity for differential diagnosis/judgments. Due to these versatile properties, we anticipate the value of Erysense for further diagnostic, prognostic, and theragnostic applications including but not limited to diabetes, iron deficiency, COVID-19, rheumatism, various red blood cell disorders and anemia, as well as inflammation-based diseases including sepsis.
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Affiliation(s)
| | - Marcelle G. M. Lopes
- Experimental Physics, Saarland University, Saarbruecken, Germany
- Cysmic GmbH, Saarbruecken, Germany
| | - Stephana Peter
- Experimental Physics, Saarland University, Saarbruecken, Germany
- Theoretical Medicine and Biosciences, Saarland University, Saarbruecken, Germany
| | - Sebastian Hof
- Experimental Physics, Saarland University, Saarbruecken, Germany
- Theoretical Medicine and Biosciences, Saarland University, Saarbruecken, Germany
| | - Greta Simionato
- Experimental Physics, Saarland University, Saarbruecken, Germany
- Institute for Clinical and Experimental Surgery, Saarland University, Campus University Hospital, Homburg, Germany
| | - Kevin Peikert
- Translational Neurodegeneration Section “Albrecht-Kossel”, Department of Neurology, University Medical Center Rostock, University of Rostock, Rostock, Germany
| | - Andreas Hermann
- Translational Neurodegeneration Section “Albrecht-Kossel”, Department of Neurology, University Medical Center Rostock, University of Rostock, Rostock, Germany
- DZNE, Deutsches Zentrum für Neurodegenerative Erkrankungen, Research Site Rostock/Greifswald, Rostock, Germany
- Center for Transdisciplinary Neurosciences Rostock (CTNR), University Medical Center Rostock, University of Rostock, Rostock, Germany
| | - Adrian Danek
- Neurologische Klinik und Poliklinik, Ludwig-Maximilians-University, Munich, Germany
| | | | - Hermann Eichler
- Institute for Clinical Hemostaseology and Transfusion Medicine, Saarland University and Saarland University Hospital, Homburg, Germany
| | - Christian Wagner
- Experimental Physics, Saarland University, Saarbruecken, Germany
- Department of Physics and Materials Science, University of Luxembourg, Luxembourg City, Luxembourg
| | - Stephan Quint
- Experimental Physics, Saarland University, Saarbruecken, Germany
- Cysmic GmbH, Saarbruecken, Germany
| | - Lars Kaestner
- Experimental Physics, Saarland University, Saarbruecken, Germany
- Theoretical Medicine and Biosciences, Saarland University, Saarbruecken, Germany
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17
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Reichel F, Kräter M, Peikert K, Glaß H, Rosendahl P, Herbig M, Rivera Prieto A, Kihm A, Bosman G, Kaestner L, Hermann A, Guck J. Changes in Blood Cell Deformability in Chorea-Acanthocytosis and Effects of Treatment With Dasatinib or Lithium. Front Physiol 2022; 13:852946. [PMID: 35444561 PMCID: PMC9013823 DOI: 10.3389/fphys.2022.852946] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2022] [Accepted: 03/08/2022] [Indexed: 12/29/2022] Open
Abstract
Misshaped red blood cells (RBCs), characterized by thorn-like protrusions known as acanthocytes, are a key diagnostic feature in Chorea-Acanthocytosis (ChAc), a rare neurodegenerative disorder. The altered RBC morphology likely influences their biomechanical properties which are crucial for the cells to pass the microvasculature. Here, we investigated blood cell deformability of five ChAc patients compared to healthy controls during up to 1-year individual off-label treatment with the tyrosine kinase inhibitor dasatinib or several weeks with lithium. Measurements with two microfluidic techniques allowed us to assess RBC deformability under different shear stresses. Furthermore, we characterized leukocyte stiffness at high shear stresses. The results showed that blood cell deformability–including both RBCs and leukocytes - in general was altered in ChAc patients compared to healthy donors. Therefore, this study shows for the first time an impairment of leukocyte properties in ChAc. During treatment with dasatinib or lithium, we observed alterations in RBC deformability and a stiffness increase for leukocytes. The hematological phenotype of ChAc patients hinted at a reorganization of the cytoskeleton in blood cells which partly explains the altered mechanical properties observed here. These findings highlight the need for a systematic assessment of the contribution of impaired blood cell mechanics to the clinical manifestation of ChAc.
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Affiliation(s)
- Felix Reichel
- Max-Planck-Institut für die Physik des Lichts and Max-Planck-Zentrum für Physik und Medizin, Erlangen, Germany
- Biotechnology Center, Center for Molecular and Cellular Bioengineering, Technische Universität Dresden, Dresden, Germany
| | - Martin Kräter
- Max-Planck-Institut für die Physik des Lichts and Max-Planck-Zentrum für Physik und Medizin, Erlangen, Germany
- Biotechnology Center, Center for Molecular and Cellular Bioengineering, Technische Universität Dresden, Dresden, Germany
| | - Kevin Peikert
- Translational Neurodegeneration Section “Albrecht Kossel”, Department of Neurology, University Medical Center Rostock, University of Rostock, Rostock, Germany
- Division for Neurodegenerative Diseases, Department of Neurology, Technische Universität Dresden, Dresden, Germany
| | - Hannes Glaß
- Translational Neurodegeneration Section “Albrecht Kossel”, Department of Neurology, University Medical Center Rostock, University of Rostock, Rostock, Germany
| | - Philipp Rosendahl
- Biotechnology Center, Center for Molecular and Cellular Bioengineering, Technische Universität Dresden, Dresden, Germany
| | - Maik Herbig
- Max-Planck-Institut für die Physik des Lichts and Max-Planck-Zentrum für Physik und Medizin, Erlangen, Germany
- Biotechnology Center, Center for Molecular and Cellular Bioengineering, Technische Universität Dresden, Dresden, Germany
| | - Alejandro Rivera Prieto
- Biotechnology Center, Center for Molecular and Cellular Bioengineering, Technische Universität Dresden, Dresden, Germany
| | - Alexander Kihm
- Department of Experimental Physics, Saarland University, Saarbrücken, Germany
| | - Giel Bosman
- Department of Biochemistry, Radboud UMC, Nijmegen, Netherlands
| | - Lars Kaestner
- Department of Experimental Physics, Saarland University, Saarbrücken, Germany
- Theoretical Medicine and Biosciences, Saarland University, Homburg, Germany
| | - Andreas Hermann
- Translational Neurodegeneration Section “Albrecht Kossel”, Department of Neurology, University Medical Center Rostock, University of Rostock, Rostock, Germany
- Division for Neurodegenerative Diseases, Department of Neurology, Technische Universität Dresden, Dresden, Germany
- Deutsches Zentrum für Neurodegenerative Erkrankungen (DZNE), Rostock/Greifswald, Rostock, Germany
- Center for Regenerative Therapies Dresden, Technische Universität Dresden, Dresden, Germany
| | - Jochen Guck
- Max-Planck-Institut für die Physik des Lichts and Max-Planck-Zentrum für Physik und Medizin, Erlangen, Germany
- Biotechnology Center, Center for Molecular and Cellular Bioengineering, Technische Universität Dresden, Dresden, Germany
- *Correspondence: Jochen Guck,
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18
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Sanchez ZAC, Vijayananda V, Virassammy DM, Rosenfeld L, Ramasubramanian AK. The interaction of vortical flows with red cells in venous valve mimics. BIOMICROFLUIDICS 2022; 16:024103. [PMID: 35282036 PMCID: PMC8896891 DOI: 10.1063/5.0078337] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/12/2021] [Accepted: 02/08/2022] [Indexed: 06/14/2023]
Abstract
The motion of cells orthogonal to the direction of main flow is of importance in natural and engineered systems. The lateral movement of red blood cells (RBCs) distal to sudden expansion is considered to influence the formation and progression of thrombosis in venous valves, aortic aneurysms, and blood-circulating devices and is also a determining parameter for cell separation applications in flow-focusing microfluidic devices. Although it is known that the unique geometry of venous valves alters the blood flow patterns and cell distribution in venous valve sinuses, the interactions between fluid flow and RBCs have not been elucidated. Here, using a dilute cell suspension in an in vitro microfluidic model of a venous valve, we quantified the spatial distribution of RBCs by microscopy and image analysis, and using micro-particle image velocimetry and 3D computational fluid dynamics simulations, we analyzed the complex flow patterns. The results show that the local hematocrit in the valve pockets is spatially heterogeneous and is significantly different from the feed hematocrit. Above a threshold shear rate, the inertial separation of streamlines and lift forces contribute to an uneven distribution of RBCs in the vortices, the entrapment of RBCs in the vortices, and non-monotonic wall shear stresses in the valve pockets. Our experimental and computational characterization provides insights into the complex interactions between fluid flow, RBC distribution, and wall shear rates in venous valve mimics, which is of relevance to understanding the pathophysiology of thrombosis and improving cell separation efficiency.
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19
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Fregin B, Biedenweg D, Otto O. Interpretation of cell mechanical experiments in microfluidic systems depend on the choice of cellular shape descriptors. BIOMICROFLUIDICS 2022; 16:024109. [PMID: 35541026 PMCID: PMC9054269 DOI: 10.1063/5.0084673] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/09/2022] [Accepted: 03/17/2022] [Indexed: 06/14/2023]
Abstract
The capability to parameterize shapes is of essential importance in biomechanics to identify cells, to track their motion, and to quantify deformation. While various shape descriptors have already been investigated to study the morphology and migration of adherent cells, little is known of how the mathematical definition of a contour impacts the outcome of rheological experiments on cells in suspension. In microfluidic systems, hydrodynamic stress distributions induce time-dependent cell deformation that needs to be quantified to determine viscoelastic properties. Here, we compared nine different shape descriptors to characterize the deformation of suspended cells in an extensional as well as shear flow using dynamic real-time deformability cytometry. While stress relaxation depends on the amplitude and duration of stress, our results demonstrate that steady-state deformation can be predicted from single cell traces even for translocation times shorter than their characteristic time. Implementing an analytical simulation, performing experiments, and testing various data analysis strategies, we compared single cell and ensemble studies to address the question of computational costs vs experimental accuracy. Results indicate that high-throughput viscoelastic measurements of cells in suspension can be performed on an ensemble scale as long as the characteristic time matches the dimensions of the microfluidic system. Finally, we introduced a score to evaluate the shape descriptor-dependent effect size for cell deformation after cytoskeletal modifications. We provide evidence that single cell analysis in an extensional flow provides the highest sensitivity independent of shape parametrization, while inverse Haralick's circularity is mostly applicable to study cells in shear flow.
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Affiliation(s)
| | | | - Oliver Otto
- Author to whom correspondence should be addressed:
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20
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Liu D, Zhang Z, Wang R, Hu J. Stability and Deformation of Vesicles in a Cylindrical Flow. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2022; 38:629-637. [PMID: 34994199 DOI: 10.1021/acs.langmuir.1c02000] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
In this work, we used dissipative particle dynamics to study the stability, deformation, and rupture of polymer vesicles confined in cylindrical channels under the flow field. The morphological evolution, elongation, and rupture of vesicles and the corresponding mechanisms were intensively investigated. Bullet-like vesicles, leaking vesicles, spherical micelles, hamburger-like micelles, and bilayers were observed by changing the degree of confinement and dimensionless shear rate. We found that increasing the dimensionless shear rate and the degree of confinement can cause the deformation or rupture of polymeric vesicles. The asphericity parameter was utilized to describe the degree of elongation of vesicles deviating from the sphere in the direction of the flow. The results show that the aggregates are more likely to be spherical when the confinement is weak, while they become elongated bullet-like shapes when the confinement is strong. The investigation of dynamics reveals that the degree of confinement and the dimensionless shear rate can affect the chain stretching and reorganization during the process of vesicle elongation. Furthermore, the rupture time of the vesicle shows a nonlinear decrease with an increase in the dimensionless shear rate, and the confinement also contributes to the rupture. The results are very useful for guiding the application of vesicles in a flow environment.
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Affiliation(s)
- Dan Liu
- Department of Polymer Science and Engineering, State Key Laboratory of Coordination Chemistry and Collaborative Innovation Center of Chemistry for Life Sciences, Key Laboratory of High Performance Polymer Material and Technology of Ministry of Education, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China
| | - Zhihao Zhang
- Department of Polymer Science and Engineering, State Key Laboratory of Coordination Chemistry and Collaborative Innovation Center of Chemistry for Life Sciences, Key Laboratory of High Performance Polymer Material and Technology of Ministry of Education, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China
| | - Rong Wang
- Department of Polymer Science and Engineering, State Key Laboratory of Coordination Chemistry and Collaborative Innovation Center of Chemistry for Life Sciences, Key Laboratory of High Performance Polymer Material and Technology of Ministry of Education, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China
| | - Jinglei Hu
- Kuang Yaming Honors School and Institute for Brain Sciences, Nanjing University, Nanjing 210023, China
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21
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Kumar D, Schroeder CM. Nonlinear Transient and Steady State Stretching of Deflated Vesicles in Flow. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2021; 37:13976-13984. [PMID: 34813335 DOI: 10.1021/acs.langmuir.1c01275] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Membrane-bound vesicles and organelles exhibit a wide array of nonspherical shapes at equilibrium, including biconcave and tubular morphologies. Despite recent progress, the stretching dynamics of deflated vesicles is not fully understood, particularly far from equilibrium where complex nonspherical shapes undergo large deformations in flow. Here, we directly observe the transient and steady-state nonlinear stretching dynamics of deflated vesicles in extensional flow using a Stokes trap. Automated flow control is used to observe vesicle dynamics over a wide range of flow rates, shape anisotropy, and viscosity contrast. Our results show that deflated vesicle membranes stretch into highly deformed shapes in flow above a critical capillary number Cac1. We further identify a second critical capillary number Cac2, above which vesicle stretch diverges in flow. Vesicles are robust to multiple nonlinear stretch-relax cycles, evidenced by relaxation of dumbbell-shaped vesicles containing thin lipid tethers following flow cessation. An analytical model is developed for vesicle deformation in flow, which enables comparison of nonlinear steady-state stretching results with theories for different reduced volumes. Our results show that the model captures the steady-state stretching of moderately deflated vesicles; however, it underpredicts the steady-state nonlinear stretching of highly deflated vesicles. Overall, these results provide a new understanding of the nonlinear stretching dynamics and membrane mechanics of deflated vesicles in flow.
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Affiliation(s)
- Dinesh Kumar
- Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Charles M Schroeder
- Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
- Department of Materials Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
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22
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Liu Y, Wang K, Sun X, Chen D, Wang J, Chen J. Advance of microfluidic constriction channel system of measuring single-cell cortical tension/specific capacitance of membrane and conductivity of cytoplasm. Cytometry A 2021; 101:434-447. [PMID: 34821462 DOI: 10.1002/cyto.a.24517] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Revised: 10/14/2021] [Accepted: 11/11/2021] [Indexed: 12/29/2022]
Abstract
This paper reported a microfluidic platform which realized the characterization of inherent single-cell biomechanical and bioelectrical parameters simultaneously. Individual cells traveled through a constriction channel with deformation images and impedance variations captured and processed into cortical tension Tc , specific membrane capacitance Csm , and cytoplasmic conductivity σcy based on an equivalent biophysical model. These properties of thousands of individual cells of K562, Jurkat, HL-60, HL-60 treated with paraformaldehyde (PA)/cytochalasin D (CD)/concanavalin A (ConA), granulocytes of Donor 1, Donor 2, and Donor 3 were quantified for the first time. Leveraging Tc , Csm , and σcy , (1) high accuracies of classifying wild-type and processed HL-60 cells (e.g., 93.5% of PA treated vs. CD treated HL-60 cells) were realized, revealing the effectiveness of using these three biophysical parameters in cell-type classification; (2) low accuracies of classifying normal granulocytes from three donors (e.g., 56.4% of Donor 1 vs. 2), indicating comparable parameters for normal granulocytes. In conclusion, this platform can characterize single-cell Tc , Csm , and σcy concurrently and quantify multiple parameters in single-cell analysis.
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Affiliation(s)
- Yan Liu
- State Key Laboratory of Transducer Technology (SKLTT), Aerospace Information Research Institute (AIR), Chinese Academy of Sciences (CAS), Beijing, China.,School of Electronic, Electrical and Communication Engineering (EECE), University of Chinese Academy of Sciences (UCAS), Beijing, China
| | - Ke Wang
- School of Electronic Engineering, Beijing University of Posts and Telecommunications, Beijing, China
| | - Xiaohao Sun
- Department of Mechanical Engineering, University of Colorado Boulder, Boulder, Colorado, USA
| | - Deyong Chen
- State Key Laboratory of Transducer Technology (SKLTT), Aerospace Information Research Institute (AIR), Chinese Academy of Sciences (CAS), Beijing, China.,School of Electronic, Electrical and Communication Engineering (EECE), University of Chinese Academy of Sciences (UCAS), Beijing, China.,School of Future Technology, University of Chinese Academy of Sciences (UCAS), Beijing, China
| | - Junbo Wang
- State Key Laboratory of Transducer Technology (SKLTT), Aerospace Information Research Institute (AIR), Chinese Academy of Sciences (CAS), Beijing, China.,School of Electronic, Electrical and Communication Engineering (EECE), University of Chinese Academy of Sciences (UCAS), Beijing, China.,School of Future Technology, University of Chinese Academy of Sciences (UCAS), Beijing, China
| | - Jian Chen
- State Key Laboratory of Transducer Technology (SKLTT), Aerospace Information Research Institute (AIR), Chinese Academy of Sciences (CAS), Beijing, China.,School of Electronic, Electrical and Communication Engineering (EECE), University of Chinese Academy of Sciences (UCAS), Beijing, China.,School of Future Technology, University of Chinese Academy of Sciences (UCAS), Beijing, China
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23
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Kubánková M, Hohberger B, Hoffmanns J, Fürst J, Herrmann M, Guck J, Kräter M. Physical phenotype of blood cells is altered in COVID-19. Biophys J 2021; 120:2838-2847. [PMID: 34087216 PMCID: PMC8169220 DOI: 10.1016/j.bpj.2021.05.025] [Citation(s) in RCA: 99] [Impact Index Per Article: 33.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Revised: 05/07/2021] [Accepted: 05/27/2021] [Indexed: 12/15/2022] Open
Abstract
Clinical syndrome coronavirus disease 2019 (COVID-19) induced by severe acute respiratory syndrome coronavirus 2 is characterized by rapid spreading and high mortality worldwide. Although the pathology is not yet fully understood, hyperinflammatory response and coagulation disorders leading to congestions of microvessels are considered to be key drivers of the still-increasing death toll. Until now, physical changes of blood cells have not been considered to play a role in COVID-19 related vascular occlusion and organ damage. Here, we report an evaluation of multiple physical parameters including the mechanical features of five frequent blood cell types, namely erythrocytes, lymphocytes, monocytes, neutrophils, and eosinophils. More than four million blood cells of 17 COVID-19 patients at different levels of severity, 24 volunteers free from infectious or inflammatory diseases, and 14 recovered COVID-19 patients were analyzed. We found significant changes in lymphocyte stiffness, monocyte size, neutrophil size and deformability, and heterogeneity of erythrocyte deformation and size. Although some of these changes recovered to normal values after hospitalization, others persisted for months after hospital discharge, evidencing the long-term imprint of COVID-19 on the body.
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Affiliation(s)
- Markéta Kubánková
- Max Planck Institute for the Science of Light & Max-Planck-Zentrum für Physik und Medizin, Erlangen, Germany
| | - Bettina Hohberger
- Department of Ophthalmology, Friedrich-Alexander-University Erlangen-Nürnberg, Erlangen, Germany
| | - Jakob Hoffmanns
- Department of Ophthalmology, Friedrich-Alexander-University Erlangen-Nürnberg, Erlangen, Germany
| | - Julia Fürst
- Department of Internal Medicine 1, University Medical Center Erlangen, Friedrich-Alexander-University Erlangen-Nürnberg, Erlangen, Germany
| | - Martin Herrmann
- Department of Internal Medicine 3, University Medical Center Erlangen, Friedrich-Alexander-University Erlangen-Nürnberg, Erlangen, Germany; Deutsches Zentrum Immuntherapie, Erlangen, Germany
| | - Jochen Guck
- Max Planck Institute for the Science of Light & Max-Planck-Zentrum für Physik und Medizin, Erlangen, Germany; Department of Physics, Friedrich-Alexander-University Erlangen-Nürnberg, Erlangen, Germany.
| | - Martin Kräter
- Max Planck Institute for the Science of Light & Max-Planck-Zentrum für Physik und Medizin, Erlangen, Germany
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24
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High-Throughput Cell Concentration Using A Piezoelectric Pump in Closed-Loop Viscoelastic Microfluidics. MICROMACHINES 2021; 12:mi12060677. [PMID: 34207912 PMCID: PMC8229193 DOI: 10.3390/mi12060677] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/23/2021] [Revised: 06/01/2021] [Accepted: 06/07/2021] [Indexed: 11/29/2022]
Abstract
Cell concentration is a critical process in biological assays and clinical diagnostics for the pre-treatment of extremely rare disease-related cells. The conventional technique for sample preconcentration and centrifugation has the limitations of a batch process requiring expensive and large equipment. Therefore, a high-throughput continuous cell concentration technique needs to be developed. However, in single-pass operation, the required concentration ratio is hard to achieve. In this study, we propose a closed-loop continuous cell concentration system using a viscoelastic non-Newtonian fluid. For miniaturized and integrated systems, two piezoelectric pumps were adopted. The pumping capability generated by a piezoelectric pump in a microfluidic channel was evaluated depending on the applied voltage, frequency, sample viscosity, and channel length. The concentration performance of the device was evaluated using 13 μm particles and white blood cells (WBCs) with different channel lengths and voltages. In the closed-loop system, the focused cells collected at the center outlet were sent back to the inlet, while the buffer solution was removed to the side outlets. Finally, to expand the clinical applicability of our closed-loop system, WBCs in lysed blood samples with 70% hematocrit and prostate cancer cells in urine samples were used. Using the closed-loop system, WBCs were concentrated by ~63.4 ± 0.8-fold within 20 min to a final volume of 160 μL using 10 mL of lysed blood sample with 70% hematocrit (~3 cP). In addition, prostate cancer cells in 10 mL urine samples were concentrated by ~64.1-fold within ~11 min due to low viscosity (~1 cP).
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25
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Zhou Q, Fidalgo J, Bernabeu MO, Oliveira MSN, Krüger T. Emergent cell-free layer asymmetry and biased haematocrit partition in a biomimetic vascular network of successive bifurcations. SOFT MATTER 2021; 17:3619-3633. [PMID: 33459318 DOI: 10.1039/d0sm01845g] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Blood is a vital soft matter, and its normal circulation in the human body relies on the distribution of red blood cells (RBCs) at successive bifurcations. Understanding how RBCs are partitioned at bifurcations is key for the optimisation of microfluidic devices as well as for devising novel strategies for diagnosis and treatment of blood-related diseases. We report the dynamics of RBC suspensions flowing through a biomimetic vascular network incorporating three generations of microchannels and two classical types of bifurcations at the arteriole level. Our microfluidic experiments with dilute and semidilute RBC suspensions demonstrate the emergence of excessive heterogeneity of RBC concentration in downstream generations upon altering the network's outflow rates. Through parallel simulations using the immersed-boundary-lattice-Boltzmann method, we reveal that the heterogeneity is attributed to upstream perturbations in the cell-free layer (CFL) and lack of its recovery between consecutive bifurcations owing to suppressed hydrodynamic lift under reduced flow conditions. In the dilute/semidilute regime, this perturbation dominates over the effect of local fractional flow at the bifurcation and can lead to inherently unfavourable child branches that are deprived of RBCs even for equal flow split. Our work highlights the importance of CFL asymmetry cascading down a vascular network, which leads to biased phase separation that deviates from established empirical predictions.
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Affiliation(s)
- Qi Zhou
- School of Engineering, Institute for Multiscale Thermofluids, University of Edinburgh, Edinburgh EH9 3FB, UK.
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26
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Sun Y, Zhang R, Chen Y. A Molecular Communication Detection Method for the Deformability of Erythrocyte Membrane in Blood Vessels. IEEE Trans Nanobioscience 2021; 20:387-395. [PMID: 33684042 DOI: 10.1109/tnb.2021.3064194] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Molecular communication (MC) inspired drug delivery holds considerable promise as a new design for targeted therapy with high efficiency and minimal toxicity. The process of drug delivery can be modelled in a blood flow-based MC system, where nanoparticles (NPs) carry therapeutic agents through the blood vessel channels to the targeted diseased tissue. Most previous studies in the flow-based MC consider a Newtonian fluid with a laminar flow, which ignores the influence of red blood cells (RBCs). However, the nature of blood flow is a complex and non-Newtonian fluid composed of proteins, platelets, plasma and deformable cells, especially RBCs. The ability to change their shapes is essential to the proper functioning of RBCs in the microvasculature. Different shapes of RBCs have a great impact on the performance of blood flow. Changes in the properties and shapes of RBCs are often associated with different diseases, such as sickle cell anemia, diabetes, and malaria. Thus, it is highly important to establish a more realistic blood flow MC model considering the deformable cells. According to our previous study, the motion and adhesion of individual NPs are modelled through the Brownian adhesion dynamics. Subsequently, this paper establishes a particle-cell hybrid model in the flow-based MC, which focuses on the RBC deformation, aggregation, and dispersion in the blood suspension. Based on the state of the RBC deformation and aggregation in the vessels with different flow rates, this paper proposes a novel methodology for detecting the deformability of the cells. The blood state in terms of RBC deformability is determined by the difference in NPs' concentration at the receiving end., this paper sheds some light on the influence of RBCs on the motion of NPs, which provides new insights on the design of targeted drug delivery and the detection of vascular diseases.
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27
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Abstract
The application of artificial intelligence (AI) in hematology it not new at all. However, it increasingly becomes part of the measurement of hematological parameters and subsequently also influences decision making. Here some examples are provided where well established parameters could be exploited better, if data are not reduced to single values but instead the entire data generation process is considered. Furthermore applications of artificial neural networks (ANN), point of care (PoC) devices and the internet of things (IoT) are discussed. Beside all the technical advancements human judgement will remain the last decision.
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Yuan J, Yin WY, Wang Y, Chen J, Zhang ZM, Tang YX, Pei SY, Tan LX, Hu XW, Fan XG, Li N. Cargo-laden erythrocyte ghosts target liver mediated by macrophages. Transfus Apher Sci 2020; 60:102930. [PMID: 32933846 DOI: 10.1016/j.transci.2020.102930] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2020] [Revised: 08/12/2020] [Accepted: 08/28/2020] [Indexed: 12/19/2022]
Abstract
Liver-targeted cargo delivery possesses great potential for the treatment of liver disease. It is urgent to find an efficient and biocompatible liver targeted delivery system. This study focused on the liver targeting properties of erythrocyte ghosts and its possible mechanism. Herein, we optimized conditions to fabricate human and mouse erythrocyte ghosts with sufficient room capable of incorporating various model substances. Erythrocyte ghosts are biocompatible cargo carriers because it is derived from autologous red blood cells (RBCs), and the cell size, zeta potential, and biconcave-disk shape of the ghosts were consistent with those of RBCs. An in vivo imaging system and positron emission tomography/computed tomography imaging showed that the ghosts were captured mainly in the liver by intravenous injection of fluorescence or 18F-fluorodeoxyglucose (FDG)-labelled ghosts into mice. In contrast, the main concentration of naked octreotide was trapped in the lungs while naked 18F-FDG was trapped in the heart. However, the concentration of cargo-loaded ghosts decreased significantly in the liver in macrophage-depleted mice. Accordingly, in vitro experiments showed that higher phosphatidylserine exposure was observed in the ghosts (38.9 %) compared to normal erythrocytes (0.69 %), and the phagocytic activity of the macrophage RAW 264.7. on the ghosts was significantly higher than that of normal erythrocytes (p < 0.001). Together they indicate that erythrocyte ghosts show liver targeting properties, and possibly owing to macrophage phagocytosis. This promising and effective therapeutic delivery system may provide therapeutic benefits for liver disease.
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Affiliation(s)
- Jiao Yuan
- Department of Infectious Diseases and Hunan Key Laboratory of Viral Hepatitis, Xiangya Hospital, Central South University, Changsha, China
| | - Wen-Yu Yin
- Department of Blood Transfusion, Xiangya Hospital, Central South University, Changsha, China
| | - Yang Wang
- Laboratory of Ethnopharmacology Institute of Integrative Medicine, Xiangya Hospital, Central South University, Changsha, China
| | - Jun Chen
- Department of Infectious Diseases and Hunan Key Laboratory of Viral Hepatitis, Xiangya Hospital, Central South University, Changsha, China
| | - Zhi-Min Zhang
- Department of Blood Transfusion, Xiangya Hospital, Central South University, Changsha, China
| | - Yong-Xiang Tang
- Department of PET Centre, Xiangya Hospital, Central South University, Changsha, China
| | - Si-Ya Pei
- Department of Infectious Diseases and Hunan Key Laboratory of Viral Hepatitis, Xiangya Hospital, Central South University, Changsha, China
| | - Lin-Xia Tan
- Department of Infectious Diseases and Hunan Key Laboratory of Viral Hepatitis, Xiangya Hospital, Central South University, Changsha, China
| | - Xing-Wang Hu
- Department of Infectious Diseases and Hunan Key Laboratory of Viral Hepatitis, Xiangya Hospital, Central South University, Changsha, China
| | - Xue-Gong Fan
- Department of Infectious Diseases and Hunan Key Laboratory of Viral Hepatitis, Xiangya Hospital, Central South University, Changsha, China
| | - Ning Li
- Department of Blood Transfusion, Xiangya Hospital, Central South University, Changsha, China.
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29
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Saadat A, Huyke DA, Oyarzun DI, Escobar PV, Øvreeide IH, Shaqfeh ESG, Santiago JG. A system for the high-throughput measurement of the shear modulus distribution of human red blood cells. LAB ON A CHIP 2020; 20:2927-2936. [PMID: 32648561 DOI: 10.1039/d0lc00283f] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Reduced deformability of red blood cells (RBCs) can affect the hemodynamics of the microcirculation and reduce oxygen transport efficiency. It is also well known that reduced RBC deformability is a signature of various physical disorders, including sepsis, and that the primary determinant of RBC deformability is the membrane shear modulus. To measure the distribution of an individual's RBC shear modulus with high throughput, we a) developed a high-fidelity computational model of RBCs in confined microchannels to inform design decisions; b) created a novel experimental system combining microfluidic flow, imaging, and image analysis; and c) performed automated comparisons between measured quantities and numerical predictions to extract quantitative measures of the RBC shear modulus for each of thousands of cells. We applied our computational simulation platform to construct the appropriate deformability figure(s) of merit to quantify RBC stiffness based on an experimentally measured, steady-state cell shape in flow through a microchannel. In particular, we determined a shape parameter based on the second moment of the cell shape that is sensitive to the changes in the membrane stiffness and cell size. We then conducted microfluidic experiments and developed custom automated image processing codes to identify and track the position and shape of individual RBCs within micro-constrictions. The fabricated microchannels include a square cross-section imaging region (7 by 7 μm) and we applied order 10 kPa pressure differences to induce order 10 mm s-1 cell velocities. The combination of modeling, microfluidics, and imaging enables, for the first time, quantitative measurement of the shear moduli of thousands of RBCs in human blood samples. We demonstrate the high-throughput features by sensitive quantification of the changes in the distribution of RBC stiffness with aging. This combined measurement and computational platform is ultimately intended to diagnose blood cell disorders in patients.
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Affiliation(s)
- Amir Saadat
- Department of Chemical Engineering, Stanford University, Stanford, CA, USA
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30
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Xu T, Lizarralde-Iragorri MA, Roman J, Ghasemi R, Lefèvre JP, Martincic E, Brousse V, Français O, El Nemer W, Le Pioufle B. Characterization of red blood cell microcirculatory parameters using a bioimpedance microfluidic device. Sci Rep 2020; 10:9869. [PMID: 32555353 PMCID: PMC7299978 DOI: 10.1038/s41598-020-66693-4] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2020] [Accepted: 05/26/2020] [Indexed: 02/07/2023] Open
Abstract
This paper describes the use of a microfluidic device comprising channels with dimensions mimicking those of the smallest capillaries found in the human microcirculation. The device structure, associated with a pair of microelectrodes, provides a tool to electrically measure the transit time of red blood cells through fine capillaries and thus generate an electrical signature for red blood cells in the context of human erythroid genetic disorders, such as sickle cell disease or hereditary spherocytosis, in which red cell elasticity is altered. Red blood cells from healthy individuals, heated or not, and red blood cells from patients with sickle cell disease or hereditary spherocytosis where characterized at a single cell level using our device. Transit time and blockade amplitude recordings were correlated with microscopic observations, and analyzed. The link between the electrical signature and the mechanical properties of the red blood cells is discussed in the paper, with greater transit time and modified blockade amplitude for heated and pathological red blood cells as compared to those from healthy individuals. Our single cell-based methodology offers a new and complementary approach to characterize red cell mechanical properties in human disorders under flow conditions mimicking the microcirculation.
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Affiliation(s)
- Tieying Xu
- Université Paris-Saclay, ENS Paris-Saclay, CNRS, Institut d'Alembert, SATIE, F-91190, Gif sur Yvette, France
| | - Maria A Lizarralde-Iragorri
- Université de Paris, UMR_S1134, BIGR, Inserm, F-75015, Paris, France
- Institut National de Transfusion Sanguine, F-75015, Paris, France
- Laboratoire d'Excellence GR-Ex, F-75013, Paris, France
| | - Jean Roman
- Université Paris-Saclay, ENS Paris-Saclay, CNRS, Institut d'Alembert, SATIE, F-91190, Gif sur Yvette, France
| | - Rasta Ghasemi
- Université Paris-Saclay, ENS Paris-Saclay, CNRS, Institut d'Alembert, F-91190, Gif sur Yvette, France
| | - Jean-Pierre Lefèvre
- Université Paris-Saclay, ENS Paris-Saclay, CNRS, PPSM, Institut d'Alembert, F-91190, Gif sur Yvette, France
- CNAM, F-75003, Paris, France
| | - Emile Martincic
- Centre de Nanosciences et de Nanotechnologies C2N, CNRS, Université Paris-Sud, Université Paris-Saclay, F-91120, Palaiseau, France
| | - Valentine Brousse
- Université de Paris, UMR_S1134, BIGR, Inserm, F-75015, Paris, France
- Institut National de Transfusion Sanguine, F-75015, Paris, France
- Laboratoire d'Excellence GR-Ex, F-75013, Paris, France
- Service de Pédiatrie Générale et Maladies Infectieuses, Hôpital Universitaire Necker Enfants Malades, F-75015, Paris, France
| | - Olivier Français
- Université Paris-Saclay, ENS Paris-Saclay, CNRS, Institut d'Alembert, SATIE, F-91190, Gif sur Yvette, France
- ESYCOM, Univ Gustave Eiffel, CNRS UMR 9007, ESIEE Paris, F-77454, Marne-la-Vallee, France
| | - Wassim El Nemer
- Université de Paris, UMR_S1134, BIGR, Inserm, F-75015, Paris, France
- Institut National de Transfusion Sanguine, F-75015, Paris, France
- Laboratoire d'Excellence GR-Ex, F-75013, Paris, France
| | - Bruno Le Pioufle
- Université Paris-Saclay, ENS Paris-Saclay, CNRS, Institut d'Alembert, SATIE, F-91190, Gif sur Yvette, France.
- Université Paris-Saclay, ENS Paris-Saclay, CNRS, Institut d'Alembert, LUMIN, F-91190, Gif sur Yvette, France.
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31
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Single-cell O 2 exchange imaging shows that cytoplasmic diffusion is a dominant barrier to efficient gas transport in red blood cells. Proc Natl Acad Sci U S A 2020; 117:10067-10078. [PMID: 32321831 PMCID: PMC7211990 DOI: 10.1073/pnas.1916641117] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Blood is routinely tested for gas-carrying capacity (total hemoglobin), but this cannot determine the speed at which red blood cells (RBCs) exchange gases. Such information is critical for evaluating the physiological fitness of RBCs, which have very limited capillary transit times (<1 s) for turning over substantial volumes of gas. We developed a method to quantify gas exchange in individual RBCs and used it to show that restricted diffusion, imposed by hemoglobin crowding, is a major barrier to gas flows. Consequently, hematological disorders manifesting a change in cell shape or hemoglobin concentration have uncharted implications on gas exchange, which we illustrate using inherited anemias. With its single-cell resolution, the method can identify physiologically inferior subpopulations, providing a clinically useful appraisal of blood quality. Disorders of oxygen transport are commonly attributed to inadequate carrying capacity (anemia) but may also relate to inefficient gas exchange by red blood cells (RBCs), a process that is poorly characterized yet assumed to be rapid. Without direct measurements of gas exchange at the single-cell level, the barriers to O2 transport and their relationship with hematological disorders remain ill defined. We developed a method to track the flow of O2 in individual RBCs by combining ultrarapid solution switching (to manipulate gas tension) with single-cell O2 saturation fluorescence microscopy. O2 unloading from RBCs was considerably slower than previously estimated in acellular hemoglobin solutions, indicating the presence of diffusional barriers in intact cells. Rate-limiting diffusion across cytoplasm was demonstrated by osmotically induced changes to hemoglobin concentration (i.e., diffusive tortuosity) and cell size (i.e., diffusion pathlength) and by comparing wild-type cells with hemoglobin H (HbH) thalassemia (shorter pathlength and reduced tortuosity) and hereditary spherocytosis (HS; expanded pathlength). Analysis of the distribution of O2 unloading rates in HS RBCs identified a subpopulation of spherocytes with greatly impaired gas exchange. Tortuosity imposed by hemoglobin was verified by demonstrating restricted diffusivity of CO2, an acidic gas, from the dissipative spread of photolytically uncaged H+ ions across cytoplasm. Our findings indicate that cytoplasmic diffusion, determined by pathlength and tortuosity, is a major barrier to efficient gas handling by RBCs. Consequently, changes in RBC shape and hemoglobin concentration, which are common manifestations of hematological disorders, can have hitherto unrecognized and clinically significant implications on gas exchange.
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