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Stuhlmüller NCX, Farrokhzad F, Kuświk P, Stobiecki F, Urbaniak M, Akhundzada S, Ehresmann A, Fischer TM, de Las Heras D. Simultaneous and independent topological control of identical microparticles in non-periodic energy landscapes. Nat Commun 2023; 14:7517. [PMID: 37980403 PMCID: PMC10657436 DOI: 10.1038/s41467-023-43390-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2023] [Accepted: 11/07/2023] [Indexed: 11/20/2023] Open
Abstract
Topological protection ensures stability of information and particle transport against perturbations. We explore experimentally and computationally the topologically protected transport of magnetic colloids above spatially inhomogeneous magnetic patterns, revealing that transport complexity can be encoded in both the driving loop and the pattern. Complex patterns support intricate transport modes when the microparticles are subjected to simple time-periodic loops of a uniform magnetic field. We design a pattern featuring a topological defect that functions as an attractor or a repeller of microparticles, as well as a pattern that directs microparticles along a prescribed complex trajectory. Using simple patterns and complex loops, we simultaneously and independently control the motion of several identical microparticles differing only in their positions above the pattern. Combining complex patterns and complex loops we transport microparticles from unknown locations to predefined positions and then force them to follow arbitrarily complex trajectories concurrently. Our findings pave the way for new avenues in transport control and dynamic self-assembly in colloidal science.
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Affiliation(s)
- Nico C X Stuhlmüller
- Theoretische Physik II, Physikalisches Institut, Universität Bayreuth, D-95440, Bayreuth, Germany
| | - Farzaneh Farrokhzad
- Experimatalphysik X, Physikalisches Institut, Universität Bayreuth, D-95440, Bayreuth, Germany
| | - Piotr Kuświk
- Institute of Molecular Physics, Polish Academy of Sciences, 60-179, Poznań, Poland
| | - Feliks Stobiecki
- Institute of Molecular Physics, Polish Academy of Sciences, 60-179, Poznań, Poland
| | - Maciej Urbaniak
- Institute of Molecular Physics, Polish Academy of Sciences, 60-179, Poznań, Poland
| | - Sapida Akhundzada
- Institute of Physics and Center for Interdisciplinary Nanostructure Science and Technology (CINSaT), University of Kassel, D-34132, Kassel, Germany
| | - Arno Ehresmann
- Institute of Physics and Center for Interdisciplinary Nanostructure Science and Technology (CINSaT), University of Kassel, D-34132, Kassel, Germany
| | - Thomas M Fischer
- Experimatalphysik X, Physikalisches Institut, Universität Bayreuth, D-95440, Bayreuth, Germany
| | - Daniel de Las Heras
- Theoretische Physik II, Physikalisches Institut, Universität Bayreuth, D-95440, Bayreuth, Germany.
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Wen Y, Jiang D, Gavriilidis A, Besenhard MO. In-Silico Conceptualisation of Continuous Millifluidic Separators for Magnetic Nanoparticles. MATERIALS 2021; 14:ma14216635. [PMID: 34772161 PMCID: PMC8586940 DOI: 10.3390/ma14216635] [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: 08/07/2021] [Revised: 10/14/2021] [Accepted: 10/30/2021] [Indexed: 11/16/2022]
Abstract
Magnetic nanoparticles are researched intensively not only for biomedical applications, but also for industrial applications including wastewater treatment and catalytic processes. Although these particles have been shown to have interesting surface properties in their bare form, their magnetisation remains a key feature, as it allows for magnetic separation. This makes them a promising carrier for precious materials and enables recovery via magnetic fields that can be turned on and off on demand, rather than using complex (nano)filtration strategies. However, designing a magnetic separator is by no means trivial, as the magnetic field and its gradient, the separator dimensions, the particle properties (such as size and susceptibility), and the throughput must be coordinated. This is showcased here for a simple continuous electromagnetic separator design requiring no expensive materials or equipment and facilitating continuous operation. The continuous electromagnetic separator chosen was based on a current-carrying wire in the centre of a capillary, which generated a radially symmetric magnetic field that could be described using cylindrical coordinates. The electromagnetic separator design was tested in-silico using a Lagrangian particle-tracking model accounting for hydrodynamics, magnetophoresis, as well as particle diffusion. This computational approach enabled the determination of separation efficiencies for varying particle sizes, magnetic field strengths, separator geometries, and flow rates, which provided insights into the complex interplay between these design parameters. In addition, the model identified the separator design allowing for the highest separation efficiency and determined the retention potential in both single and multiple separators in series. The work demonstrated that throughputs of ~1/4 L/h could be achieved for 250–500 nm iron oxide nanoparticle solutions, using less than 10 separator units in series.
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Affiliation(s)
- Yanzhe Wen
- Department of Chemical Engineering, University College London, Torrington Place, London WC1E 7JE, UK;
| | - Dai Jiang
- Department of Electronic and Electrical Engineering, University College London, Torrington Place, London WC1E 7JE, UK;
| | - Asterios Gavriilidis
- Department of Chemical Engineering, University College London, Torrington Place, London WC1E 7JE, UK;
- Correspondence: (A.G.); (M.O.B.)
| | - Maximilian O. Besenhard
- Department of Chemical Engineering, University College London, Torrington Place, London WC1E 7JE, UK;
- School of Chemical and Process Engineering, University of Leeds, Leeds LS2 9JT, UK
- Correspondence: (A.G.); (M.O.B.)
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Short- and Long-Range Microparticle Transport on Permalloy Disk Arrays in Time-Varying Magnetic Fields. MAGNETOCHEMISTRY 2021. [DOI: 10.3390/magnetochemistry7080120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
We investigate maneuvering superparamagnetic microparticles, or beads, in a remotely-controlled, automated way across arrays of few-micron-diameter permalloy disks. This technique is potentially useful for applying tunable forces to or for sorting biological structures that can be attached to magnetic beads, for example nucleic acids, proteins, or cells. The particle manipulation method being investigated relies on a combination of stray fields emanating from permalloy disks as well as time-varying externally applied magnetic fields. Unlike previous work, we closely examine particle motion during a capture, rotate, and controlled repulsion mechanism for particle transport. We measure particle velocities during short-range motion—the controlled repulsion of a bead from one disk toward another—and compare this motion to a simulation based on stray fields from disk edges. We also observe the phase-slipping and phase-locked motion of particles engaging in long-range transport in this manipulation scheme.
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Sajjad U, Klingbeil F, Block F, Holländer RB, Bhatti S, Lage E, McCord J. Efficient flowless separation of mixed microbead populations on periodic ferromagnetic surface structures. LAB ON A CHIP 2021; 21:3174-3183. [PMID: 34190746 DOI: 10.1039/d1lc00161b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
The simultaneous separational control of motion of individual objects is vital to achieve high efficiency separation for biological analytes in biomedical applications. Here, we show the selective and directed movement of different populations of microbeads depending on their size in a flowless environment by means of a hexagonally structured soft-magnetic microchip platform. By adjusting strength and asymmetry of a modulated in-plane magnetic field, discrete and switchable movement patterns of two different types of beads above a magnetic surface structure are achieved. Starting from a heterogeneous mixture of bead populations and depending on the type of field sequences, directional forward transport of one type of beads is achieved, while the other bead population is immobilized. Despite significant size and magnetic content distributions within each population of microbeads, high separation efficiencies are demonstrated. The selection and movement processes are supported by full-scale magnetofluidic numerical simulations. The magnetic platform allowing multidirectional and selective microbead movement can greatly contribute to the progress of functional lab-on-chip and future diagnostics devices.
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Affiliation(s)
- Umer Sajjad
- Institute for Materials Science, Kiel University, Kaiserstraße 2, D-24143 Kiel, Germany.
| | - Finn Klingbeil
- Institute for Materials Science, Kiel University, Kaiserstraße 2, D-24143 Kiel, Germany.
| | - Findan Block
- Institute for Materials Science, Kiel University, Kaiserstraße 2, D-24143 Kiel, Germany.
| | - Rasmus B Holländer
- Institute for Materials Science, Kiel University, Kaiserstraße 2, D-24143 Kiel, Germany.
| | - Shehroz Bhatti
- Institute for Materials Science, Kiel University, Kaiserstraße 2, D-24143 Kiel, Germany.
| | - Enno Lage
- Institute for Materials Science, Kiel University, Kaiserstraße 2, D-24143 Kiel, Germany.
| | - Jeffrey McCord
- Institute for Materials Science, Kiel University, Kaiserstraße 2, D-24143 Kiel, Germany.
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Rampini S, Li P, Gandhi D, Mutas M, Ran YF, Carr M, Lee GU. Design of micromagnetic arrays for on-chip separation of superparamagnetic bead aggregates and detection of a model protein and double-stranded DNA analytes. Sci Rep 2021; 11:5302. [PMID: 33674645 PMCID: PMC7935980 DOI: 10.1038/s41598-021-84395-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2020] [Accepted: 02/10/2021] [Indexed: 01/17/2023] Open
Abstract
Magnetically actuated lab-on-a-chip (LOC) technologies have enabled rapid, highly efficient separation of specific biomarkers and cells from complex biological samples. Nonlinear magnetophoresis (NLM) is a technique that uses a microfabricated magnet array (MMA) and a time varying external magnetic field to precisely control the transport of superparamagnetic (SPM) beads on the surface of a chip based on their size and magnetization. We analyze the transport and separation behavior of SPM monomers and dimers on four MMA geometries, i.e., circular, triangular, square and rectangular shaped micromagnets, across a range of external magnetic field rotation frequencies. The measured critical frequency of the SPM beads on an MMA, i.e., the velocity for which the hydrodynamic drag on a bead exceeds the magnetic force, is closely related to the local magnetic flux density landscape on a micromagnet in the presence of an external magnetic field. A set of design criteria has been established for the optimization of MMAs for NLM separation, with particular focus on the shape of the micromagnets forming the array. The square MMA was used to detect a model protein biomarker and gene fragment based on a magnetic bead assembly (MBA) assay. This assay uses ligand functionalized SPM beads to capture and directly detect an analyte through the formation of SPM bead aggregates. These beads aggregates were detected through NLM separation and microscopic analysis resulting in a highly sensitive assay that did not use carrier fluid.
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Affiliation(s)
- Stefano Rampini
- School of Chemistry, University College Dublin, Belfield, Dublin, Ireland
| | - Peng Li
- School of Chemistry, University College Dublin, Belfield, Dublin, Ireland
| | - Dhruv Gandhi
- School of Chemistry, University College Dublin, Belfield, Dublin, Ireland
| | - Marina Mutas
- School of Chemistry, University College Dublin, Belfield, Dublin, Ireland
| | - Ying Fen Ran
- School of Chemistry, University College Dublin, Belfield, Dublin, Ireland
| | - Michael Carr
- National Virus Reference Laboratory, University College Dublin, Belfield, Dublin, Ireland.,Global Institution for Collaborative Research and Education (GI-CoRE), Hokkaido University, Kita-ku, Sapporo, Japan
| | - Gil U Lee
- School of Chemistry, University College Dublin, Belfield, Dublin, Ireland. .,Conway Institute for Biomolecular and Biomedical Research, University College Dublin, Dublin, Ireland.
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6
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Gandhi D, Li P, Rampini S, Parent C, Lee GU. Optical detection of the magnetophoretic transport of superparamagnetic beads on a micromagnetic array. Sci Rep 2020; 10:12876. [PMID: 32733006 PMCID: PMC7392889 DOI: 10.1038/s41598-020-69757-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2019] [Accepted: 07/13/2020] [Indexed: 11/09/2022] Open
Abstract
Micromagnetic arrays (MMAs) have proven to be powerful tools for controlling the transport and separation of bioanalytes, i.e., they allow bioanalyte-superparamagnetic (SPM) bead complexes of specific size and magnetization to be moved in a synchronized manner that is precisely controlled with the orientation of an external magnetic field. This article presents a laser-photodetector system for the simple detection of individual SPM beads moving on a specific region of an MMA. This system detects the SPM beads through the change in intensity of reflective light as they move from the highly reflective micromagnetics to the supporting substrate. We demonstrate that this opti-MMA system allowed the size, number, and magnetic and optical properties of the SPM beads to be rapidly determined for regions > 49 µm2 in size. The response of the opti-MMA system was characterized in several optical configurations to develop a theoretical description of its sensitivity and dynamic range. The speed, low-cost, and sensitivity of this system promises to allow MMAs to be readily applied in in vitro diagnostics and biosensing.
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Affiliation(s)
- Dhruv Gandhi
- School of Chemistry, University College Dublin, Belfield, Dublin 4, Ireland
| | - Peng Li
- School of Chemistry, University College Dublin, Belfield, Dublin 4, Ireland.
| | - Stefano Rampini
- School of Chemistry, University College Dublin, Belfield, Dublin 4, Ireland
| | - Charlotte Parent
- School of Chemistry, University College Dublin, Belfield, Dublin 4, Ireland
| | - Gil U Lee
- School of Chemistry, University College Dublin, Belfield, Dublin 4, Ireland.
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7
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Li P, Gandhi D, Mutas M, Ran YF, Carr M, Rampini S, Hall W, Lee GU. Direct identification of the herpes simplex virus UL27 gene through single particle manipulation and optical detection using a micromagnetic array. NANOSCALE 2020; 12:3482-3490. [PMID: 31971211 DOI: 10.1039/c9nr10362g] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Magnetophoretic lab on a chip technologies are rapidly evolving into integrated systems for the identification of biomarkers and cells with ultra-high sensitivity. We demonstrate the highly efficient detection of the Human herpes simplex virus type 1 (HSV) UL27 gene through the programmed assembly of superparamagnetic (SPM) nanoparticles based on oligonucleotide hybridization. The state of assembly of the SPM nanoparticles was determined by optical signature of the synchronized motion on the beads on a micromagnetic array (MMA). This technique has been used to identify <200 copies of the HSV UL27 gene without amplification in less than 20 minutes. The MAA can also be used to separate gene-SPM bead aggregates from millions of unreacted SPM beads based on nonlinear magnetophoresis (NLM). The MMA-optical detection system promises to enable highly sensitive, nucleic acid analysis to be performed without amplification and with the consumption of minimal amounts of reagent.
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Affiliation(s)
- Peng Li
- School of Chemistry and Chemical Biology, University College Dublin, Belfield, Dublin 4, Ireland.
| | - Dhruv Gandhi
- School of Chemistry and Chemical Biology, University College Dublin, Belfield, Dublin 4, Ireland.
| | - Marina Mutas
- School of Chemistry and Chemical Biology, University College Dublin, Belfield, Dublin 4, Ireland.
| | - Yin-Fen Ran
- School of Chemistry and Chemical Biology, University College Dublin, Belfield, Dublin 4, Ireland.
| | - Michael Carr
- UCD National Virus Reference Laboratory, University College Dublin, Belfield, Dublin 4, Ireland and Global Station for Zoonosis Control, Global Institution for Collaborative Research and Education (GI-CoRE), Hokkaido University, Sapporo 001-0020, Japan
| | - Stefano Rampini
- School of Chemistry and Chemical Biology, University College Dublin, Belfield, Dublin 4, Ireland.
| | - William Hall
- UCD National Virus Reference Laboratory, University College Dublin, Belfield, Dublin 4, Ireland
| | - Gil U Lee
- School of Chemistry and Chemical Biology, University College Dublin, Belfield, Dublin 4, Ireland.
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8
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Pierce CJ, Osborne E, Mumper E, Lower BH, Lower SK, Sooryakumar R. Thrust and Power Output of the Bacterial Flagellar Motor: A Micromagnetic Tweezers Approach. Biophys J 2019; 117:1250-1257. [PMID: 31540710 DOI: 10.1016/j.bpj.2019.08.036] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2019] [Revised: 08/27/2019] [Accepted: 08/30/2019] [Indexed: 02/03/2023] Open
Abstract
One of the most common swimming strategies employed by microorganisms is based on the use of rotating helical filaments, called flagella, that are powered by molecular motors. Determining the physical properties of this propulsive system is crucial to understanding the behavior of these organisms. Furthermore, the ability to dynamically monitor the activity of the flagellar motor is a valuable indicator of the overall energetics of the cell. In this work, inherently magnetic bacteria confined in micromagnetic CoFe traps are used to directly and noninvasively determine the flagellar thrust force and swimming speed of motile cells. The technique permits determination of the ratio of propulsive force/swimming speed (the hydrodynamic resistance) and the power output of the flagellar motor for individual cells over extended time periods. Cells subjected to ultraviolet radiation are observed to experience exponential decays in power output as a function of exposure time. By noninvasively measuring thrust, velocity, and power output over time at a single-cell level, this technique can serve as the foundation for fundamental studies of bacterial hydrodynamics and also provides a novel, to our knowledge, tether-free probe of single-cell energetics over time.
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Affiliation(s)
| | - Emily Osborne
- Department of Physics, The Ohio State University, Columbus, Ohio
| | - Eric Mumper
- School of Environment and Natural Resources, The Ohio State University, Columbus, Ohio
| | - Brian H Lower
- School of Environment and Natural Resources, The Ohio State University, Columbus, Ohio
| | - Steven K Lower
- School of Environment and Natural Resources, The Ohio State University, Columbus, Ohio; School of Earth Sciences, The Ohio State University, Columbus, Ohio; Department of Microbial Infection and Immunity, The Ohio State University, Columbus, Ohio
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9
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Chiriacò MS, Bianco M, Nigro A, Primiceri E, Ferrara F, Romano A, Quattrini A, Furlan R, Arima V, Maruccio G. Lab-on-Chip for Exosomes and Microvesicles Detection and Characterization. SENSORS (BASEL, SWITZERLAND) 2018; 18:E3175. [PMID: 30241303 PMCID: PMC6210978 DOI: 10.3390/s18103175] [Citation(s) in RCA: 93] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/08/2018] [Revised: 09/05/2018] [Accepted: 09/16/2018] [Indexed: 12/11/2022]
Abstract
Interest in extracellular vesicles and in particular microvesicles and exosomes, which are constitutively produced by cells, is on the rise for their huge potential as biomarkers in a high number of disorders and pathologies as they are considered as carriers of information among cells, as well as being responsible for the spreading of diseases. Current methods of analysis of microvesicles and exosomes do not fulfill the requirements for their in-depth investigation and the complete exploitation of their diagnostic and prognostic value. Lab-on-chip methods have the potential and capabilities to bridge this gap and the technology is mature enough to provide all the necessary steps for a completely automated analysis of extracellular vesicles in body fluids. In this paper we provide an overview of the biological role of extracellular vesicles, standard biochemical methods of analysis and their limits, and a survey of lab-on-chip methods that are able to meet the needs of a deeper exploitation of these biological entities to drive their use in common clinical practice.
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Affiliation(s)
| | - Monica Bianco
- CNR NANOTEC Institute of Nanotechnology, via Monteroni, 73100 Lecce, Italy.
| | - Annamaria Nigro
- Institute of Experimental Neurology, Division of Neuroscience, San Raffaele Scientific Institute, 20132 Milan, Italy.
| | | | - Francesco Ferrara
- CNR NANOTEC Institute of Nanotechnology, via Monteroni, 73100 Lecce, Italy.
- STMicroelectronics, Via Monteroni, I-73100 Lecce, Italy.
| | - Alessandro Romano
- Institute of Experimental Neurology, Division of Neuroscience, San Raffaele Scientific Institute, 20132 Milan, Italy.
| | - Angelo Quattrini
- Institute of Experimental Neurology, Division of Neuroscience, San Raffaele Scientific Institute, 20132 Milan, Italy.
| | - Roberto Furlan
- Institute of Experimental Neurology, Division of Neuroscience, San Raffaele Scientific Institute, 20132 Milan, Italy.
| | - Valentina Arima
- CNR NANOTEC Institute of Nanotechnology, via Monteroni, 73100 Lecce, Italy.
| | - Giuseppe Maruccio
- CNR NANOTEC Institute of Nanotechnology, via Monteroni, 73100 Lecce, Italy.
- Department of Mathematics and Physics, University of Salento, via Monteroni, 73100 Lecce, Italy.
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10
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Rampini S, Li P, Lee GU. Micromagnet arrays enable precise manipulation of individual biological analyte-superparamagnetic bead complexes for separation and sensing. LAB ON A CHIP 2016; 16:3645-63. [PMID: 27542153 DOI: 10.1039/c6lc00707d] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
In this article, we review lab on a chip (LOC) devices that have been developed for processing magnetically labelled biological analytes, e.g., proteins, nucleic acids, viruses and cells, based on micromagnetic structures and a time-varying magnetic field. We describe the methods that have been developed for fabricating micromagnetic arrays and the bioprocessing operations that have been demonstrated using superparamagnetic (SPM) beads, i.e., programmed transport, switching, separation of specific analytes, and pumping and mixing of fluids in microchannels. The primary advantage of micromagnet devices is that they make it possible to develop systems that control individual SPM beads, enabling high-efficiency separation and analysis. These devices do not require hydrodynamic control and lend themselves to parallel processing of large arrays of SPM beads with modest levels of power consumption. Micromagnet devices are well suited for bioanalytical applications that require high-resolution separation, e.g., detection of rare cell types such as circulating tumour cells, or biosensor applications that require multiple magnetic bioprocessing operations on a single chip.
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Affiliation(s)
- S Rampini
- School of Chemistry and Chemical Biology, UCD, Dublin, Ireland.
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11
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Rampini S, Kilinc D, Li P, Monteil C, Gandhi D, Lee GU. Micromagnet arrays for on-chip focusing, switching, and separation of superparamagnetic beads and single cells. LAB ON A CHIP 2015; 15:3370-3379. [PMID: 26160691 DOI: 10.1039/c5lc00581g] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Nonlinear magnetophoresis (NLM) is a novel approach for on-chip transport and separation of superparamagnetic (SPM) beads, based on a travelling magnetic field wave generated by the combination of a micromagnet array (MMA) and an applied rotating magnetic field. Here, we present two novel MMA designs that allow SPM beads to be focused, sorted, and separated on-chip. Converging MMAs were used to rapidly collect the SPM beads from a large region of the chip and focus them into synchronised lines. We characterise the collection efficiency of the devices and demonstrate that they can facilitate on-chip analysis of populations of SPM beads using a single-point optical detector. The diverging MMAs were used to control the transport of the beads and to separate them based on their size. The separation efficiency of these devices was determined by the orientation of the magnetisation of the micromagnets relative to the external magnetic field and the size of the beads and relative to that of micromagnets. By controlling these parameters and the rotation of the external magnetic field we demonstrated the controlled transport of SPM bead-labelled single MDA-MB-231 cells. The use of these novel MMAs promises to allow magnetically-labelled cells to be efficiently isolated and then manipulated on-chip for analysis with high-resolution chemical and physical techniques.
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Affiliation(s)
- S Rampini
- Bionanoscience Group, School of Chemistry and Chemical Biology, UCD, Dublin, Ireland.
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12
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Kilinc D, Blasiak A, Lee GU. Microtechnologies for studying the role of mechanics in axon growth and guidance. Front Cell Neurosci 2015; 9:282. [PMID: 26283918 PMCID: PMC4515553 DOI: 10.3389/fncel.2015.00282] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2015] [Accepted: 07/10/2015] [Indexed: 12/18/2022] Open
Abstract
The guidance of axons to their proper targets is not only a crucial event in neurodevelopment, but also a potential therapeutic target for neural repair. Axon guidance is mediated by various chemo- and haptotactic cues, as well as the mechanical interactions between the cytoskeleton and the extracellular matrix (ECM). Axonal growth cones, dynamic ends of growing axons, convert external stimuli to biochemical signals, which, in turn, are translated into behavior, e.g., turning or retraction, via cytoskeleton-matrix linkages. Despite the inherent mechanical nature of the problem, the role of mechanics in axon guidance is poorly understood. Recent years has witnessed the application of a range of microtechnologies in neurobiology, from microfluidic circuits to single molecule force spectroscopy. In this mini-review, we describe microtechnologies geared towards dissecting the mechanical aspects of axon guidance, divided into three categories: controlling the growth cone microenvironment, stimulating growth cones with externally applied forces, and measuring forces exerted by the growth cones. A particular emphasis is given to those studies that combine multiple techniques, as dictated by the complexity of the problem.
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Affiliation(s)
- Devrim Kilinc
- Bionanosciences Group, School of Chemisty and Chemical Biology, University College Dublin Belfield, Dublin, Ireland
| | - Agata Blasiak
- Bionanosciences Group, School of Chemisty and Chemical Biology, University College Dublin Belfield, Dublin, Ireland
| | - Gil U Lee
- Bionanosciences Group, School of Chemisty and Chemical Biology, University College Dublin Belfield, Dublin, Ireland
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13
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Kilinc D, Blasiak A, O'Mahony JJ, Lee GU. Low piconewton towing of CNS axons against diffusing and surface-bound repellents requires the inhibition of motor protein-associated pathways. Sci Rep 2014; 4:7128. [PMID: 25417891 PMCID: PMC4241520 DOI: 10.1038/srep07128] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2014] [Accepted: 11/03/2014] [Indexed: 12/24/2022] Open
Abstract
Growth cones, dynamic structures at axon tips, integrate chemical and physical stimuli and translate them into coordinated axon behaviour, e.g., elongation or turning. External force application to growth cones directs and enhances axon elongation in vitro; however, direct mechanical stimulation is rarely combined with chemotactic stimulation. We describe a microfluidic device that exposes isolated cortical axons to gradients of diffusing and substrate-bound molecules, and permits the simultaneous application of piconewton (pN) forces to multiple individual growth cones via magnetic tweezers. Axons treated with Y-27632, a RhoA kinase inhibitor, were successfully towed against Semaphorin 3A gradients, which repel untreated axons, with less than 12 pN acting on a small number of neural cell adhesion molecules. Treatment with Y-27632 or monastrol, a kinesin-5 inhibitor, promoted axon towing on substrates coated with chondroitin sulfate proteoglycans, potent axon repellents. Thus, modulating key molecular pathways that regulate contractile stress generation in axons counteracts the effects of repellent molecules and promotes tension-induced growth. The demonstration of parallel towing of axons towards inhibitory environments with minute forces suggests that mechanochemical stimulation may be a promising therapeutic approach for the repair of the damaged central nervous system, where regenerating axons face repellent factors over-expressed in the glial scar.
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Affiliation(s)
- Devrim Kilinc
- UCD Nanomedicine Centre, School of Chemistry and Chemical Biology, University College Dublin, Belfield, Dublin 4, Ireland
| | - Agata Blasiak
- UCD Nanomedicine Centre, School of Chemistry and Chemical Biology, University College Dublin, Belfield, Dublin 4, Ireland
| | - James J O'Mahony
- UCD Nanomedicine Centre, School of Chemistry and Chemical Biology, University College Dublin, Belfield, Dublin 4, Ireland
| | - Gil U Lee
- UCD Nanomedicine Centre, School of Chemistry and Chemical Biology, University College Dublin, Belfield, Dublin 4, Ireland
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14
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Lee W, Kwon D, Chung B, Jung GY, Au A, Folch A, Jeon S. Ultrarapid detection of pathogenic bacteria using a 3D immunomagnetic flow assay. Anal Chem 2014; 86:6683-8. [PMID: 24856003 PMCID: PMC4362721 DOI: 10.1021/ac501436d] [Citation(s) in RCA: 90] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
We developed a novel 3D immunomagnetic flow assay for the rapid detection of pathogenic bacteria in a large-volume food sample. Antibody-functionalized magnetic nanoparticle clusters (AbMNCs) were magnetically immobilized on the surfaces of a 3D-printed cylindrical microchannel. The injection of a Salmonella-spiked sample solution into the microchannel produced instant binding between the AbMNCs and the Salmonella bacteria due to their efficient collisions. Nearly perfect capture of the AbMNCs and AbMNCs-Salmonella complexes was achieved under a high flow rate by stacking permanent magnets with spacers inside the cylindrical separator to maximize the magnetic force. The concentration of the bacteria in solution was determined using ATP luminescence measurements. The detection limit was better than 10 cfu/mL, and the overall assay time, including the binding, rinsing, and detection steps for a 10 mL sample took less than 3 min. To our knowledge, the 3D immunomagnetic flow assay described here provides the fastest high-sensitivity, high-capacity method for the detection of pathogenic bacteria.
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Affiliation(s)
- Wonjae Lee
- Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), San 31, Hyoja-dong, Nam-gu, Pohang, Korea
| | - Donghoon Kwon
- Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), San 31, Hyoja-dong, Nam-gu, Pohang, Korea
| | - Boram Chung
- School of Interdisciplinary Bioscience and Bioengineering, Pohang University of Science and Technology (POSTECH), San 31, Hyoja-dong, Nam-gu, Pohang, Korea
| | - Gyoo Yeol Jung
- Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), San 31, Hyoja-dong, Nam-gu, Pohang, Korea
- School of Interdisciplinary Bioscience and Bioengineering, Pohang University of Science and Technology (POSTECH), San 31, Hyoja-dong, Nam-gu, Pohang, Korea
| | - Anthony Au
- Department of Bioengineering, University of Washington, Seattle, Washington 98105, United States
| | - Albert Folch
- Department of Bioengineering, University of Washington, Seattle, Washington 98105, United States
| | - Sangmin Jeon
- Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), San 31, Hyoja-dong, Nam-gu, Pohang, Korea
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Ran YF, Fields C, Muzard J, Liauchuk V, Carr M, Hall W, Lee GU. Rapid, highly sensitive detection of herpes simplex virus-1 using multiple antigenic peptide-coated superparamagnetic beads. Analyst 2014; 139:6126-34. [DOI: 10.1039/c4an00774c] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We demonstrate a label free assay employing scattering to determine the aggregation state of peptide-functionalized superparamagnetic beads. HSV-1 virus at 200 virus particles per mL was detected in 30 min, demonstrating potential use in point of care testing.
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Affiliation(s)
- Ying-Fen Ran
- Conway Institute for Biomolecular and Biomedical Science
- School of Chemistry and Chemical Biology
- University College Dublin
- Dublin 4, Ireland
| | - Conor Fields
- Conway Institute for Biomolecular and Biomedical Science
- School of Chemistry and Chemical Biology
- University College Dublin
- Dublin 4, Ireland
| | - Julien Muzard
- Conway Institute for Biomolecular and Biomedical Science
- School of Chemistry and Chemical Biology
- University College Dublin
- Dublin 4, Ireland
| | - Viktoryia Liauchuk
- Conway Institute for Biomolecular and Biomedical Science
- School of Chemistry and Chemical Biology
- University College Dublin
- Dublin 4, Ireland
| | - Michael Carr
- Centre for Research on Infectious Diseases
- School of Medicine
- University College Dublin
- Dublin 4, Ireland
| | - William Hall
- Centre for Research on Infectious Diseases
- School of Medicine
- University College Dublin
- Dublin 4, Ireland
| | - Gil U. Lee
- Conway Institute for Biomolecular and Biomedical Science
- School of Chemistry and Chemical Biology
- University College Dublin
- Dublin 4, Ireland
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