1
|
Barekatain M, Liu Y, Archambeau A, Cherezov V, Fraser S, White KL, Hayes MA. Insulator-based dielectrophoresis-assisted separation of insulin secretory vesicles. eLife 2024; 13:e74989. [PMID: 39190030 PMCID: PMC11349295 DOI: 10.7554/elife.74989] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2021] [Accepted: 07/24/2024] [Indexed: 08/28/2024] Open
Abstract
Organelle heterogeneity and inter-organelle contacts within a single cell contribute to the limited sensitivity of current organelle separation techniques, thus hindering organelle subpopulation characterization. Here, we use direct current insulator-based dielectrophoresis (DC-iDEP) as an unbiased separation method and demonstrate its capability by identifying distinct distribution patterns of insulin vesicles from INS-1E insulinoma cells. A multiple voltage DC-iDEP strategy with increased range and sensitivity has been applied, and a differentiation factor (ratio of electrokinetic to dielectrophoretic mobility) has been used to characterize features of insulin vesicle distribution patterns. We observed a significant difference in the distribution pattern of insulin vesicles isolated from glucose-stimulated cells relative to unstimulated cells, in accordance with maturation of vesicles upon glucose stimulation. We interpret the difference in distribution pattern to be indicative of high-resolution separation of vesicle subpopulations. DC-iDEP provides a path for future characterization of subtle biochemical differences of organelle subpopulations within any biological system.
Collapse
Affiliation(s)
- Mahta Barekatain
- Department of Chemistry, Bridge Institute, USC Michelson Center for Convergent Bioscience, University of Southern CaliforniaLos AngelesUnited States
| | - Yameng Liu
- School of Molecular Sciences, Arizona State UniversityTempeUnited States
| | - Ashley Archambeau
- Department of Chemistry, Bridge Institute, USC Michelson Center for Convergent Bioscience, University of Southern CaliforniaLos AngelesUnited States
| | - Vadim Cherezov
- Department of Chemistry, Bridge Institute, USC Michelson Center for Convergent Bioscience, University of Southern CaliforniaLos AngelesUnited States
| | - Scott Fraser
- Department of Biological Sciences, Bridge Institute, USC Michelson Center for Convergent Bioscience, University of Southern CaliforniaLos AngelesUnited States
| | - Kate L White
- Department of Chemistry, Bridge Institute, USC Michelson Center for Convergent Bioscience, University of Southern CaliforniaLos AngelesUnited States
| | - Mark A Hayes
- School of Molecular Sciences, Arizona State UniversityTempeUnited States
| |
Collapse
|
2
|
Zavatski S, Martin OJF. Visual and Quantitative Analysis of the Trapping Volume in Dielectrophoresis of Nanoparticles. NANO LETTERS 2024; 24:10305-10312. [PMID: 39133749 PMCID: PMC11342383 DOI: 10.1021/acs.nanolett.4c02903] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2024] [Revised: 08/06/2024] [Accepted: 08/06/2024] [Indexed: 08/22/2024]
Abstract
Nanoparticle manipulation requires careful analysis of the forces at play. Unfortunately, traditional force measurement techniques based on the particle velocity do not provide sufficient resolution, while balancing approaches involving counteracting forces are often cumbersome. Here, we demonstrate that a nanoparticle dielectrophoretic response can be quantitatively studied by a straightforward visual delineation of the dielectrophoretic trapping volume. We reveal this volume by detecting the width of the region depleted of gold nanoparticles by the dielectrophoretic force. Comparison of the measured widths for various nanoparticle sizes with numerical simulations obtained by solving the particle-conservation equation shows excellent agreement, thus providing access to the particle physical properties, such as polarizability and size. These findings can be further extended to investigate various types of nano-objects, including bio- and molecular aggregates, and offer a robust characterization tool that can enhance the control of matter at the nanoscale.
Collapse
Affiliation(s)
- Siarhei Zavatski
- Nanophotonics and Metrology
Laboratory (NAM), Swiss Federal Institute
of Technology Lausanne (EPFL), Lausanne 1015, Switzerland
| | - Olivier J. F. Martin
- Nanophotonics and Metrology
Laboratory (NAM), Swiss Federal Institute
of Technology Lausanne (EPFL), Lausanne 1015, Switzerland
| |
Collapse
|
3
|
Lapizco-Encinas BH. Nonlinear Electrokinetic Methods of Particles and Cells. ANNUAL REVIEW OF ANALYTICAL CHEMISTRY (PALO ALTO, CALIF.) 2024; 17:243-264. [PMID: 38360552 DOI: 10.1146/annurev-anchem-061622-040810] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/17/2024]
Abstract
Nonlinear electrokinetic phenomena offer label-free, portable, and robust approaches for particle and cell assessment, including selective enrichment, separation, sorting, and characterization. The field of electrokinetics has evolved substantially since the first separation reports by Arne Tiselius in the 1930s. The last century witnessed major advances in the understanding of the weak-field theory, which supported developments in the use of linear electrophoresis and its adoption as a routine analytical technique. More recently, an improved understanding of the strong-field theory enabled the development of nonlinear electrokinetic techniques such as electrorotation, dielectrophoresis, and nonlinear electrophoresis. This review discusses the operating principles and recent applications of these three nonlinear electrokinetic phenomena for the analysis and manipulation of particles and cells and provides an overview of some of the latest developments in the field of nonlinear electrokinetics.
Collapse
Affiliation(s)
- Blanca H Lapizco-Encinas
- Microscale Bioseparations Laboratory and Department of Biomedical Engineering, Rochester Institute of Technology, Rochester, New York, USA;
| |
Collapse
|
4
|
Aguilella-Arzo M, Hoogerheide DP, Doucet M, Wang H, Aguilella VM. Charged Biological Membranes Repel Large Neutral Molecules by Surface Dielectrophoresis and Counterion Pressure. J Am Chem Soc 2024; 146:2701-2710. [PMID: 38291994 PMCID: PMC10835712 DOI: 10.1021/jacs.3c12348] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2023] [Revised: 12/13/2023] [Accepted: 12/14/2023] [Indexed: 02/01/2024]
Abstract
Macromolecular crowding is the usual condition of cells. The implications of the crowded cellular environment for protein stability and folding, protein-protein interactions, and intracellular transport drive a growing interest in quantifying the effects of crowding. While the properties of crowded solutions have been extensively studied, less attention has been paid to the interaction of crowders with the cellular boundaries, i.e., membranes. However, membranes are key components of cells and most subcellular organelles, playing a central role in regulating protein channel and receptor functions by recruiting and binding charged and neutral solutes. While membrane interactions with charged solutes are dominated by electrostatic forces, here we show that significant charge-induced forces also exist between membranes and neutral solutes. Using neutron reflectometry measurements and molecular dynamics simulations of poly(ethylene glycol) (PEG) polymers of different molecular weights near charged and neutral membranes, we demonstrate the roles of surface dielectrophoresis and counterion pressure in repelling PEG from charged membrane surfaces. The resulting depletion zone is expected to have consequences for drug design and delivery, the activity of proteins near membrane surfaces, and the transport of small molecules along the membrane surface.
Collapse
Affiliation(s)
- Marcel Aguilella-Arzo
- Laboratory
of Molecular Biophysics, Department of Physics, Universitat Jaume I, 12071, Castellón, Spain
| | - David P. Hoogerheide
- Center
for Neutron Research, National Institute
of Standards and Technology, Gaithersburg, Maryland 20899, United States
| | - Mathieu Doucet
- Neutron
Scattering Division, Oak Ridge National
Laboratory, Oak Ridge, Tennessee 37831, United States
| | - Hanyu Wang
- Center
for Nanophase Materials Sciences, Oak Ridge
National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - Vicente M. Aguilella
- Laboratory
of Molecular Biophysics, Department of Physics, Universitat Jaume I, 12071, Castellón, Spain
| |
Collapse
|
5
|
Mondal TK, West JH, Williams SJ. An electrospun nanofiber mat as an electrode for AC-dielectrophoretic trapping of nanoparticles. NANOSCALE 2023; 15:18241-18249. [PMID: 37947459 DOI: 10.1039/d3nr04496c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2023]
Abstract
In order to trap nanoparticles with dielectrophoresis, high electric field gradients are needed. Here we created large area (>mm2) conductive carbon nanofiber mats to trap nanoparticles with dielectrophoresis. The electrospun fiber mats had an average diameter of 267 ± 94 nm and a conductivity of 2.55 S cm-1. Relative to cleanroom procedures, this procedure is less expensive in creating bulk conductive nanoscale features. The electrospun fiber mat was used as one electrode, with an indium-tin-oxide glass slide serving as the other (separated approximately 150 μm). Numerical models showed that conductive nanoscale fibers can generate significant field gradients sufficient to overcome Brownian transport of nanoparticles. Our experiments trapped 20 nm fluorescent polystyrene beads at 7 Vrms and 1 kHz. Trapping is further enhanced through simultaneous electrohydrodynamic motion. Overall, this straightforward electrospun fiber mat can serve as a foundation for future use in microscale electrokinetic devices.
Collapse
Affiliation(s)
- Tonoy K Mondal
- Department of Mechanical Engineering, University of Louisville, Louisville, KY-40292, USA.
| | - J Hunter West
- Department of Mechanical Engineering, University of Louisville, Louisville, KY-40292, USA.
| | - Stuart J Williams
- Department of Mechanical Engineering, University of Louisville, Louisville, KY-40292, USA.
| |
Collapse
|
6
|
Torres-Castro K, Acuña-Umaña K, Lesser-Rojas L, Reyes DR. Microfluidic Blood Separation: Key Technologies and Critical Figures of Merit. MICROMACHINES 2023; 14:2117. [PMID: 38004974 PMCID: PMC10672873 DOI: 10.3390/mi14112117] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/05/2023] [Revised: 11/01/2023] [Accepted: 11/10/2023] [Indexed: 11/26/2023]
Abstract
Blood is a complex sample comprised mostly of plasma, red blood cells (RBCs), and other cells whose concentrations correlate to physiological or pathological health conditions. There are also many blood-circulating biomarkers, such as circulating tumor cells (CTCs) and various pathogens, that can be used as measurands to diagnose certain diseases. Microfluidic devices are attractive analytical tools for separating blood components in point-of-care (POC) applications. These platforms have the potential advantage of, among other features, being compact and portable. These features can eventually be exploited in clinics and rapid tests performed in households and low-income scenarios. Microfluidic systems have the added benefit of only needing small volumes of blood drawn from patients (from nanoliters to milliliters) while integrating (within the devices) the steps required before detecting analytes. Hence, these systems will reduce the associated costs of purifying blood components of interest (e.g., specific groups of cells or blood biomarkers) for studying and quantifying collected blood fractions. The microfluidic blood separation field has grown since the 2000s, and important advances have been reported in the last few years. Nonetheless, real POC microfluidic blood separation platforms are still elusive. A widespread consensus on what key figures of merit should be reported to assess the quality and yield of these platforms has not been achieved. Knowing what parameters should be reported for microfluidic blood separations will help achieve that consensus and establish a clear road map to promote further commercialization of these devices and attain real POC applications. This review provides an overview of the separation techniques currently used to separate blood components for higher throughput separations (number of cells or particles per minute). We present a summary of the critical parameters that should be considered when designing such devices and the figures of merit that should be explicitly reported when presenting a device's separation capabilities. Ultimately, reporting the relevant figures of merit will benefit this growing community and help pave the road toward commercialization of these microfluidic systems.
Collapse
Affiliation(s)
- Karina Torres-Castro
- Biophysical and Biomedical Measurements Group, National Institute of Standards and Technology (NIST), 100 Bureau Drive, Gaithersburg, MD 20899, USA;
- Theiss Research, La Jolla, CA 92037, USA
| | - Katherine Acuña-Umaña
- Medical Devices Master’s Program, Instituto Tecnológico de Costa Rica (ITCR), Cartago 30101, Costa Rica
| | - Leonardo Lesser-Rojas
- Research Center in Atomic, Nuclear and Molecular Sciences (CICANUM), San José 11501, Costa Rica;
- School of Physics, Universidad de Costa Rica (UCR), San José 11501, Costa Rica
| | - Darwin R. Reyes
- Biophysical and Biomedical Measurements Group, National Institute of Standards and Technology (NIST), 100 Bureau Drive, Gaithersburg, MD 20899, USA;
| |
Collapse
|
7
|
Cho YS, Gwak SJ. Novel Sensing Technique for Stem Cells Differentiation Using Dielectric Spectroscopy of Their Proteins. SENSORS (BASEL, SWITZERLAND) 2023; 23:2397. [PMID: 36904601 PMCID: PMC10007102 DOI: 10.3390/s23052397] [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: 01/16/2023] [Revised: 02/12/2023] [Accepted: 02/20/2023] [Indexed: 06/18/2023]
Abstract
Dielectric spectroscopy (DS) is the primary technique to observe the dielectric properties of biomaterials. DS extracts complex permittivity spectra from measured frequency responses such as the scattering parameters or impedances of materials over the frequency band of interest. In this study, an open-ended coaxial probe and vector network analyzer were used to characterize the complex permittivity spectra of protein suspensions of human mesenchymal stem cells (hMSCs) and human osteogenic sarcoma (Saos-2) cells in distilled water at frequencies ranging from 10 MHz to 43.5 GHz. The complex permittivity spectra of the protein suspensions of hMSCs and Saos-2 cells revealed two major dielectric dispersions, β and γ, offering three distinctive features for detecting the differentiation of stem cells: the distinctive values in the real and imaginary parts of the complex permittivity spectra as well as the relaxation frequency in the β-dispersion. The protein suspensions were analyzed using a single-shell model, and a dielectrophoresis (DEP) study was performed to determine the relationship between DS and DEP. In immunohistochemistry, antigen-antibody reactions and staining are required to identify the cell type; in contrast, DS eliminates the use of biological processes, while also providing numerical values of the dielectric permittivity of the material-under-test to detect differences. This study suggests that the application of DS can be expanded to detect stem cell differentiation.
Collapse
Affiliation(s)
- Young Seek Cho
- Department of Electronic Engineering, Wonkwang University, Iksan 54538, Jeollabuk-do, Republic of Korea
| | - So-Jung Gwak
- Department of Chemical Engineering, Wonkwang University, Iksan 54538, Jeollabuk-do, Republic of Korea
| |
Collapse
|
8
|
Zavatski S, Bandarenka H, Martin OJF. Protein Dielectrophoresis with Gradient Array of Conductive Electrodes Sheds New Light on Empirical Theory. Anal Chem 2023; 95:2958-2966. [PMID: 36692365 PMCID: PMC9909730 DOI: 10.1021/acs.analchem.2c04708] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Dielectrophoresis (DEP) is a versatile tool for the precise microscale manipulation of a broad range of substances. To unleash the full potential of DEP for the manipulation of complex molecular-sized particulates such as proteins requires the development of appropriate theoretical models and their comprehensive experimental verification. Here, we construct an original DEP platform and test the Hölzel-Pethig empirical model for protein DEP. Three different proteins are studied: lysozyme, BSA, and lactoferrin. Their molecular Clausius-Mossotti function is obtained by detecting their trapping event via the measurement of the fluorescence intensity to identify the minimum electric field gradient required to overcome dispersive forces. We observe a significant discrepancy with published theoretical data and, after a very careful analysis to rule out experimental errors, conclude that more sophisticated theoretical models are required for the response of molecular entities in DEP fields. The developed experimental platform, which includes arrays of sawtooth metal electrode pairs with varying gaps and produces variations of the electric field gradient, provides a versatile tool that can broaden the utilization of DEP for molecular entities.
Collapse
Affiliation(s)
- Siarhei Zavatski
- Nanophotonics
and Metrology Laboratory (NAM), Swiss Federal
Institute of Technology Lausanne (EPFL), Lausanne1015, Switzerland,,
| | - Hanna Bandarenka
- The
Polytechnic School, Arizona State University, Mesa, Arizona85212, United States
| | - Olivier J. F. Martin
- Nanophotonics
and Metrology Laboratory (NAM), Swiss Federal
Institute of Technology Lausanne (EPFL), Lausanne1015, Switzerland,
| |
Collapse
|
9
|
Prüfer M, Wenger C, Bier FF, Laux EM, Hölzel R. Activity of AC electrokinetically immobilized horseradish peroxidase. Electrophoresis 2022; 43:1920-1933. [PMID: 35904497 DOI: 10.1002/elps.202200073] [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: 03/25/2022] [Revised: 06/22/2022] [Accepted: 07/18/2022] [Indexed: 12/14/2022]
Abstract
Dielectrophoresis (DEP) is an AC electrokinetic effect mainly used to manipulate cells. Smaller particles, like virions, antibodies, enzymes, and even dye molecules can be immobilized by DEP as well. In principle, it was shown that enzymes are active after immobilization by DEP, but no quantification of the retained activity was reported so far. In this study, the activity of the enzyme horseradish peroxidase (HRP) is quantified after immobilization by DEP. For this, HRP is immobilized on regular arrays of titanium nitride ring electrodes of 500 nm diameter and 20 nm widths. The activity of HRP on the electrode chip is measured with a limit of detection of 60 fg HRP by observing the enzymatic turnover of Amplex Red and H2 O2 to fluorescent resorufin by fluorescence microscopy. The initial activity of the permanently immobilized HRP equals up to 45% of the activity that can be expected for an ideal monolayer of HRP molecules on all electrodes of the array. Localization of the immobilizate on the electrodes is accomplished by staining with the fluorescent product of the enzyme reaction. The high residual activity of enzymes after AC field induced immobilization shows the method's suitability for biosensing and research applications.
Collapse
Affiliation(s)
- Mareike Prüfer
- Fraunhofer Institute for Cell Therapy and Immunology, Branch Bioanalytics and Bioprocesses (IZI-BB), Potsdam-Golm, Germany
| | - Christian Wenger
- IHP GmbH - Leibniz Institute for Innovative Microelectronics, Frankfurt/Oder, Germany
| | - Frank F Bier
- Institute of Biochemistry and Biology, University of Potsdam, Potsdam-Golm, Germany
| | - Eva-Maria Laux
- Fraunhofer Institute for Cell Therapy and Immunology, Branch Bioanalytics and Bioprocesses (IZI-BB), Potsdam-Golm, Germany
| | - Ralph Hölzel
- Fraunhofer Institute for Cell Therapy and Immunology, Branch Bioanalytics and Bioprocesses (IZI-BB), Potsdam-Golm, Germany
| |
Collapse
|
10
|
Henriksson A, Neubauer P, Birkholz M. Dielectrophoresis: An Approach to Increase Sensitivity, Reduce Response Time and to Suppress Nonspecific Binding in Biosensors? BIOSENSORS 2022; 12:784. [PMID: 36290922 PMCID: PMC9599301 DOI: 10.3390/bios12100784] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/17/2022] [Revised: 09/12/2022] [Accepted: 09/20/2022] [Indexed: 11/25/2022]
Abstract
The performance of receptor-based biosensors is often limited by either diffusion of the analyte causing unreasonable long assay times or a lack of specificity limiting the sensitivity due to the noise of nonspecific binding. Alternating current (AC) electrokinetics and its effect on biosensing is an increasing field of research dedicated to address this issue and can improve mass transfer of the analyte by electrothermal effects, electroosmosis, or dielectrophoresis (DEP). Accordingly, several works have shown improved sensitivity and lowered assay times by order of magnitude thanks to the improved mass transfer with these techniques. To realize high sensitivity in real samples with realistic sample matrix avoiding nonspecific binding is critical and the improved mass transfer should ideally be specific to the target analyte. In this paper we cover recent approaches to combine biosensors with DEP, which is the AC kinetic approach with the highest selectivity. We conclude that while associated with many challenges, for several applications the approach could be beneficial, especially if more work is dedicated to minimizing nonspecific bindings, for which DEP offers interesting perspectives.
Collapse
Affiliation(s)
- Anders Henriksson
- Chair of Bioprocess Engineering, Department of Biotechnology, Technische Universität Berlin, Ackerstraße 76, 13355 Berlin, Germany
| | - Peter Neubauer
- Chair of Bioprocess Engineering, Department of Biotechnology, Technische Universität Berlin, Ackerstraße 76, 13355 Berlin, Germany
| | - Mario Birkholz
- IHP—Leibniz-Institut für Innovative Mikroelektronik, Im Technologiepark 25, 15236 Frankfurt (Oder), Germany
| |
Collapse
|
11
|
Elkeles T, Park S, Werner JG, Weitz DA, Yossifon G. Dielectrophoretic Characterization of Dynamic Microcapsules and Their Magnetophoretic Manipulation. ACS APPLIED MATERIALS & INTERFACES 2022; 14:15765-15773. [PMID: 35322665 DOI: 10.1021/acsami.1c23482] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
In this work, we present dielectrophoresis (DEP) and in situ electrorotation (ROT) characterization of reversibly stimuli-responsive "dynamic" microcapsules that change the physicochemical properties of their shells under varying pH conditions and can encapsulate and release (macro)molecular cargo on demand. Specifically, these capsules are engineered to open (close) their shell under high (low) pH conditions and thus to release (retain) their encapsulated load or to capture and trap (macro)molecular samples from their environment. We show that the steady-state DEP and ROT spectra of these capsules can be modeled using a single-shell model and that the conductivity of their shells is influenced most by the pH. Furthermore, we measured the transient response of the angular velocity of the capsules under rotating electric field conditions, which allows us to directly determine the characteristic time scales of the underlying physical processes. In addition, we demonstrate the magnetic manipulation of microcapsules with embedded magnetic nanoparticles for lab-on-chip tasks such as encapsulation and release at designated locations and the in situ determination of their physicochemical state using on-chip ROT. The insight gained will enable the advanced design and operation of these dynamic drug delivery and smart lab-on-chip transport systems.
Collapse
Affiliation(s)
- Tom Elkeles
- Faculty of Mechanical Engineering, Technion-Israel Institute of Technology, Haifa 3200003, Israel
| | - Sinwook Park
- Faculty of Mechanical Engineering, Technion-Israel Institute of Technology, Haifa 3200003, Israel
| | - Jörg G Werner
- John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, United States
- Department of Mechanical Engineering, Boston University, Boston, Massachusetts 02215, United States
| | - David A Weitz
- John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, United States
| | - Gilad Yossifon
- Faculty of Mechanical Engineering, Technion-Israel Institute of Technology, Haifa 3200003, Israel
| |
Collapse
|
12
|
Pethig R. Protein Dielectrophoresis: A Tale of Two Clausius-Mossottis-Or Something Else? MICROMACHINES 2022; 13:261. [PMID: 35208384 PMCID: PMC8876334 DOI: 10.3390/mi13020261] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/19/2022] [Revised: 01/31/2022] [Accepted: 02/03/2022] [Indexed: 11/17/2022]
Abstract
Standard DEP theory, based on the Clausius-Mossotti (CM) factor derived from solving the boundary-value problem of macroscopic electrostatics, fails to describe the dielectrophoresis (DEP) data obtained for 22 different globular proteins over the past three decades. The calculated DEP force appears far too small to overcome the dispersive forces associated with Brownian motion. An empirical theory, employing the equivalent of a molecular version of the macroscopic CM-factor, predicts a protein's DEP response from the magnitude of the dielectric β-dispersion produced by its relaxing permanent dipole moment. A new theory, supported by molecular dynamics simulations, replaces the macroscopic boundary-value problem with calculation of the cross-correlation between the protein and water dipoles of its hydration shell. The empirical and formal theory predicts a positive DEP response for protein molecules up to MHz frequencies, a result consistently reported by electrode-based (eDEP) experiments. However, insulator-based (iDEP) experiments have reported negative DEP responses. This could result from crystallization or aggregation of the proteins (for which standard DEP theory predicts negative DEP) or the dominating influences of electrothermal and other electrokinetic (some non-linear) forces now being considered in iDEP theory.
Collapse
Affiliation(s)
- Ronald Pethig
- Institute for Integrated Micro and Nano Systems, School of Engineering & Electronics, The University of Edinburgh, The King's Buildings, Edinburgh EH9 3JF, UK
| |
Collapse
|
13
|
Shi L, Esfandiari L. Emerging on-chip electrokinetic based technologies for purification of circulating cancer biomarkers towards liquid biopsy: A review. Electrophoresis 2021; 43:288-308. [PMID: 34791687 DOI: 10.1002/elps.202100234] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Revised: 11/12/2021] [Accepted: 11/12/2021] [Indexed: 12/11/2022]
Abstract
Early detection of cancer can significantly reduce mortality and save lives. However, the current cancer diagnosis is highly dependent on costly, complex, and invasive procedures. Thus, a great deal of effort has been devoted to exploring new technologies based on liquid biopsy. Since liquid biopsy relies on detection of circulating biomarkers from biofluids, it is critical to isolate highly purified cancer-related biomarkers, including circulating tumor cells (CTCs), cell-free nucleic acids (cell-free DNA and cell-free RNA), small extracellular vesicles (exosomes), and proteins. The current clinical purification techniques are facing a number of drawbacks including low purity, long processing time, high cost, and difficulties in standardization. Here, we review a promising solution, on-chip electrokinetic-based methods, that have the advantage of small sample volume requirement, minimal damage to the biomarkers, rapid, and label-free criteria. We have also discussed the existing challenges of current on-chip electrokinetic technologies and suggested potential solutions that may be worthy of future studies.
Collapse
Affiliation(s)
- Leilei Shi
- Department of Electrical Engineering and Computer Science, College of Engineering and Applied Science, University of Cincinnati, Cincinnati, Ohio, USA
| | - Leyla Esfandiari
- Department of Electrical Engineering and Computer Science, College of Engineering and Applied Science, University of Cincinnati, Cincinnati, Ohio, USA.,Department of Biomedical Engineering, College of Engineering and Applied Science, University of Cincinnati, Cincinnati, Ohio, USA
| |
Collapse
|
14
|
Latypova L, Puzenko A, Poluektov Y, Anashkina A, Petrushanko I, Bogdanova A, Feldman Y. Hydration of methemoglobin studied by in silico modeling and dielectric spectroscopy. J Chem Phys 2021; 155:015101. [PMID: 34241395 DOI: 10.1063/5.0054697] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
The hemoglobin concentration of 35 g/dl of human red blood cells is close to the solubility threshold. Using microwave dielectric spectroscopy, we have assessed the amount of water associated with hydration shells of methemoglobin as a function of its concentration in the presence or absence of ions. We estimated water-hemoglobin interactions to interpret the obtained data. Within the concentration range of 5-10 g/dl of methemoglobin, ions play an important role in defining the free-to-bound water ratio competing with hemoglobin to recruit water molecules for the hydration shell. At higher concentrations, hemoglobin is a major contributor to the recruitment of water to its hydration shell. Furthermore, the amount of bound water does not change as the hemoglobin concentration is increased from 15 to 30 g/dl, remaining at the level of ∼20% of the total intracellular water pool. The theoretical evaluation of the ratio of free and bound water for the hemoglobin concentration in the absence of ions corresponds with the experimental results and shows that the methemoglobin molecule binds about 1400 water molecules. These observations suggest that within the concentration range close to the physiological one, hemoglobin molecules are so close to each other that their hydration shells interact. In this case, the orientation of the hemoglobin molecules is most likely not stochastic, but rather supports partial neutralization of positive and negative charges at the protein surface. Furthermore, deformation of the red blood cell shape results in the rearrangement of these structures.
Collapse
Affiliation(s)
- Larisa Latypova
- Department of Applied Physics, The Hebrew University of Jerusalem, Givat Ram 91904, Israel
| | - Alexander Puzenko
- Department of Applied Physics, The Hebrew University of Jerusalem, Givat Ram 91904, Israel
| | - Yuri Poluektov
- Engelhart Institute of Molecular Biology, Russian Academy of Science, Vavilov St. 32, 119991 Moscow, Russia
| | - Anastasia Anashkina
- Engelhart Institute of Molecular Biology, Russian Academy of Science, Vavilov St. 32, 119991 Moscow, Russia
| | - Irina Petrushanko
- Engelhart Institute of Molecular Biology, Russian Academy of Science, Vavilov St. 32, 119991 Moscow, Russia
| | - Anna Bogdanova
- Red Blood Cell Research Group, Institute of Veterinary Physiology, University of Zürich, Winterthurerstrasse 260, CH-8057 Zürich, Switzerland
| | - Yuri Feldman
- Department of Applied Physics, The Hebrew University of Jerusalem, Givat Ram 91904, Israel
| |
Collapse
|
15
|
Abalmasov VA. Dipole ordering of water molecules in cordierite: Monte Carlo simulations. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2021; 33:34LT01. [PMID: 34062519 DOI: 10.1088/1361-648x/ac06f0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Accepted: 06/01/2021] [Indexed: 06/12/2023]
Abstract
Electric dipoles of water molecules, enclosed singly in regularly spaced nanopores of a cordierite crystal, become ordered at low temperature due to their mutual interaction and show the frequency dependence of their dielectric susceptibility, typical for relaxor ferroelectrics, according to recent experimental data. The corresponding phase transition is accompanied by anomalies in thermodynamic quantities, such as heat capacity and dielectric susceptibility, which are calculated here using the Monte Carlo method, and their agreement with the experimental data is discussed. Despite the increase in the correlation length, the partially filled dipole lattice at low temperatures, according to the calculations, does not have long-range order and corresponds to a dipole glass. This simulation gives a microscopical insight into the formation of polar nanoregions in relaxor ferroelectrics and the temperature dependence of their size.
Collapse
|
16
|
Lapizco-Encinas BH. Microscale nonlinear electrokinetics for the analysis of cellular materials in clinical applications: a review. Mikrochim Acta 2021; 188:104. [PMID: 33651196 DOI: 10.1007/s00604-021-04748-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2020] [Accepted: 02/06/2021] [Indexed: 12/16/2022]
Abstract
This review article presents a discussion of some of the latest advancements in the field of microscale electrokinetics for the analysis of cells and subcellular materials in clinical applications. The introduction presents an overview on the use of electric fields, i.e., electrokinetics, in microfluidics devices and discusses the potential of electrokinetic-based methods for the analysis of liquid biopsies in clinical and point-of-care applications. This is followed by four comprehensive sections that present some of the newest findings on the analysis of circulating tumor cells, blood (red blood cells, white blood cells, and platelets), stem cells, and subcellular particles (extracellular vesicles and mitochondria). The valuable contributions discussed here (with 131 references) were mainly published during the last 3 to 4 years, providing the reader with an overview of the state-of-the-art in the use of microscale electrokinetic methods in clinical analysis. Finally, the conclusions summarize the main advancements and discuss the future prospects.
Collapse
Affiliation(s)
- Blanca H Lapizco-Encinas
- Microscale Bioseparations Laboratory and Biomedical Engineering Department, Rochester Institute of Technology, Institute Hall (Bldg. 73), Room 3103, 160 Lomb Memorial Drive, Rochester, NY, 14623-5604, USA.
| |
Collapse
|