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Freitag S, Baumgartner B, Radel S, Schwaighofer A, Varriale A, Pennacchio A, D'Auria S, Lendl B. A thermoelectrically stabilized aluminium acoustic trap combined with attenuated total reflection infrared spectroscopy for detection of Escherichia coli in water. Lab Chip 2021; 21:1811-1819. [PMID: 33949396 DOI: 10.1039/d0lc01264e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Acoustic trapping is a non-contact particle manipulation method that holds great potential for performing automated assays. We demonstrate an aluminium acoustic trap in combination with attenuated total reflection Fourier-transform infrared spectroscopy (ATR-FTIR) for detection of E. coli in water. The thermal conductivity of aluminium was exploited to thermo-electrically heat and hold the acoustic trap at the desired assay temperature of 37 °C. Systematic characterisation and optimisation of the acoustic trap allowed high flow rates while maintaining high acoustic trapping performance. The ATR element serves not only as a reflector for ultrasound standing wave generation but also as a sensing interface. The enzyme conversion induced by alkaline phosphatase-labelled bacteria was directly monitored in the acoustic trap using ATR-FTIR spectroscopy. Sequential injection analysis allowed automated liquid handling, including non-contact bacteria retention, washing and enzyme-substrate exchange within the acoustic trap. The presented method was able to detect E. coli concentrations as low as 1.95 × 106 bacteria per mL in 197 min. The demonstrated ultrasound assisted assay paves the way to fully automated bacteria detection devices based on acoustic trapping combined with ATR-FTIR spectroscopy.
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Affiliation(s)
- Stephan Freitag
- Research Division of Environmental Analytics, Process Analytics and Sensors, Institute of Chemical Technologies and Analytics, Technische Universität Wien, Getreidemarkt 9/164-UPA, 1060 Vienna, Austria.
| | - Bettina Baumgartner
- Research Division of Environmental Analytics, Process Analytics and Sensors, Institute of Chemical Technologies and Analytics, Technische Universität Wien, Getreidemarkt 9/164-UPA, 1060 Vienna, Austria.
| | - Stefan Radel
- Research Division of Environmental Analytics, Process Analytics and Sensors, Institute of Chemical Technologies and Analytics, Technische Universität Wien, Getreidemarkt 9/164-UPA, 1060 Vienna, Austria.
| | - Andreas Schwaighofer
- Research Division of Environmental Analytics, Process Analytics and Sensors, Institute of Chemical Technologies and Analytics, Technische Universität Wien, Getreidemarkt 9/164-UPA, 1060 Vienna, Austria.
| | - Antonio Varriale
- Institute of Food Science, CNR, Via Roma 64, 83100 Avellino, Italy
| | | | - Sabato D'Auria
- Institute of Food Science, CNR, Via Roma 64, 83100 Avellino, Italy
| | - Bernhard Lendl
- Research Division of Environmental Analytics, Process Analytics and Sensors, Institute of Chemical Technologies and Analytics, Technische Universität Wien, Getreidemarkt 9/164-UPA, 1060 Vienna, Austria.
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2
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Wieland K, Tauber S, Gasser C, Rettenbacher LA, Lux L, Radel S, Lendl B. In-Line Ultrasound-Enhanced Raman Spectroscopy Allows for Highly Sensitive Analysis with Improved Selectivity in Suspensions. Anal Chem 2019; 91:14231-14238. [DOI: 10.1021/acs.analchem.9b01105] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Karin Wieland
- Institute of Chemical Technologies and Analytics, Research Division Environmental, Process Analytics and Sensors, TU Wien, 1060 Vienna, Austria
| | - Stefan Tauber
- Institute of Chemical Technologies and Analytics, Research Division Environmental, Process Analytics and Sensors, TU Wien, 1060 Vienna, Austria
| | - Christoph Gasser
- Institute of Chemical Technologies and Analytics, Research Division Environmental, Process Analytics and Sensors, TU Wien, 1060 Vienna, Austria
| | - Lukas A. Rettenbacher
- Institute of Chemical Technologies and Analytics, Research Division Environmental, Process Analytics and Sensors, TU Wien, 1060 Vienna, Austria
| | - Laurin Lux
- Institute of Chemical Technologies and Analytics, Research Division Environmental, Process Analytics and Sensors, TU Wien, 1060 Vienna, Austria
| | - Stefan Radel
- Institute of Chemical Technologies and Analytics, Research Division Environmental, Process Analytics and Sensors, TU Wien, 1060 Vienna, Austria
| | - Bernhard Lendl
- Institute of Chemical Technologies and Analytics, Research Division Environmental, Process Analytics and Sensors, TU Wien, 1060 Vienna, Austria
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3
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Freitag S, Baumgartner B, Tauber S, Gasser C, Radel S, Schwaighofer A, Lendl B. An Acoustic Trap for Bead Injection Attenuated Total Reflection Infrared Spectroscopy. Anal Chem 2019; 91:7672-7678. [DOI: 10.1021/acs.analchem.9b00611] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Stephan Freitag
- Institute of Chemical Technologies and Analytics, Technische Universität Wien, Getreidemarkt 9/164-UPA, 1060 Vienna, Austria
| | - Bettina Baumgartner
- Institute of Chemical Technologies and Analytics, Technische Universität Wien, Getreidemarkt 9/164-UPA, 1060 Vienna, Austria
| | - Stefan Tauber
- Institute of Chemical Technologies and Analytics, Technische Universität Wien, Getreidemarkt 9/164-UPA, 1060 Vienna, Austria
| | - Christoph Gasser
- Institute of Chemical Technologies and Analytics, Technische Universität Wien, Getreidemarkt 9/164-UPA, 1060 Vienna, Austria
| | - Stefan Radel
- Institute of Chemical Technologies and Analytics, Technische Universität Wien, Getreidemarkt 9/164-UPA, 1060 Vienna, Austria
| | - Andreas Schwaighofer
- Institute of Chemical Technologies and Analytics, Technische Universität Wien, Getreidemarkt 9/164-UPA, 1060 Vienna, Austria
| | - Bernhard Lendl
- Institute of Chemical Technologies and Analytics, Technische Universität Wien, Getreidemarkt 9/164-UPA, 1060 Vienna, Austria
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4
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Koch C, Brandstetter M, Wechselberger P, Lorantfy B, Plata M, Radel S, Herwig C, Lendl B. Ultrasound-enhanced attenuated total reflection mid-infrared spectroscopy in-line probe: acquisition of cell spectra in a bioreactor. Anal Chem 2015; 87:2314-20. [PMID: 25582569 PMCID: PMC4333607 DOI: 10.1021/ac504126v] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2014] [Accepted: 01/12/2015] [Indexed: 11/29/2022]
Abstract
This article presents a novel method for selective acquisition of Fourier transform infrared (FT-IR) spectra of microorganisms in-line during fermentation, using Saccharomyces cerevisiae as an example. The position of the cells relative to the sensitive region of the attenuated total reflection (ATR) FT-IR probe was controlled by combing a commercially available ATR in-line probe with contact-free, gentle particle manipulation by ultrasonic standing waves. A prototype probe was successfully constructed, assembled, and tested in-line during fed-batch fermentations of S. cerevisiae. Control over the position of the cells was achieved by tuning the ultrasound frequency: 2.41 MHz was used for acquisition of spectra of the cells (pushing frequency f(p)) and 1.87 MHz, for retracting the cells from the ATR element, therefore allowing spectra of the medium to be acquired. Accumulation of storage carbohydrates (trehalose and glycogen) inside the cells was induced by a lack of a nitrogen source in the feed medium. These changes in biochemical composition were visible in the spectra of the cells recorded in-line during the application of f(p) and could be verified by reference spectra of dried cell samples recorded off-line with a FT-IR microscope. Comparison of the cell spectra with spectra of trehalose, glycogen, glucose, and mannan, i.e., the major carbohydrates present in S. cerevisiae, and principal components analysis revealed that the changes observed in the cell spectra correlated well with the bands specific for trehalose and glycogen. This proves the applicability and capability of ultrasound-enhanced in-line ATR mid-IR spectroscopy as a real-time PAT method for the in situ monitoring of cellular biochemistry during fermentation.
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Affiliation(s)
- Cosima Koch
- Institute
of Chemical Technologies and Analytics, Vienna University of Technology, Getreidemarkt 9/164-UPA, 1060 Vienna, Austria
| | - Markus Brandstetter
- Institute
of Chemical Technologies and Analytics, Vienna University of Technology, Getreidemarkt 9/164-UPA, 1060 Vienna, Austria
| | - Patrick Wechselberger
- Institute
of Chemical Engineering, Vienna University
of Technology, Gumpendorferstraße
1a, 1060 Vienna, Austria
- Christian
Doppler Laboratory for Mechanistic and Physiological Methods for Improved
Bioprocesses, Institute of
Chemical Engineering, Vienna University
of Technology, Getreidemarkt
9/166, 1060 Vienna, Austria
| | - Bettina Lorantfy
- Institute
of Chemical Engineering, Vienna University
of Technology, Gumpendorferstraße
1a, 1060 Vienna, Austria
| | - Maria
Reyes Plata
- Institute
of Chemical Technologies and Analytics, Vienna University of Technology, Getreidemarkt 9/164-UPA, 1060 Vienna, Austria
| | - Stefan Radel
- Institute
of Chemical Technologies and Analytics, Vienna University of Technology, Getreidemarkt 9/164-UPA, 1060 Vienna, Austria
| | - Christoph Herwig
- Institute
of Chemical Engineering, Vienna University
of Technology, Gumpendorferstraße
1a, 1060 Vienna, Austria
- Christian
Doppler Laboratory for Mechanistic and Physiological Methods for Improved
Bioprocesses, Institute of
Chemical Engineering, Vienna University
of Technology, Getreidemarkt
9/166, 1060 Vienna, Austria
| | - Bernhard Lendl
- Institute
of Chemical Technologies and Analytics, Vienna University of Technology, Getreidemarkt 9/164-UPA, 1060 Vienna, Austria
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Koch C, Brandstetter M, Lendl B, Radel S. Ultrasonic manipulation of yeast cells in suspension for absorption spectroscopy with an immersible mid-infrared fiberoptic probe. Ultrasound Med Biol 2013; 39:1094-101. [PMID: 23562020 PMCID: PMC3655382 DOI: 10.1016/j.ultrasmedbio.2013.01.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2012] [Revised: 01/08/2013] [Accepted: 01/10/2013] [Indexed: 05/22/2023]
Abstract
Recent advances in combining ultrasonic particle manipulation with attenuated total reflection infrared spectroscopy of yeast suspensions are presented. Infrared spectroscopy provides highly specific molecular information about the sample. It has not been applicable to in-line monitoring of cells during fermentation, however, because positioning cells in the micron-thin measurement region of the attenuated total reflection probe was not possible. Ultrasonic radiation forces exerted on suspended particles by an ultrasonic standing wave can result in the buildup of agglomerates in the nodal planes, hence enabling the manipulation of suspended cells on the microscopic scale. When a chamber setup and a prototype in-line applicable probe were used, successful control over the position of the yeast cells relative to the attenuated total reflection sensor surface could be proven. Both rate of increase and maximum mid-infrared absorption of yeast-specific bands during application of a pushing frequency (chamber setup: 1.863 MHz, in-line probe: 1.990 MHz) were found to correlate with yeast cell concentration.
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Affiliation(s)
| | | | | | - Stefan Radel
- Address correspondence to: Stefan Radel, Institute of Chemical Technologies and Analytics, Vienna University of Technology, Getreidemarkt 9/164 AC, 1060 Vienna, Austria.
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6
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Abstract
One important niche for multi-wavelength resonators is the filtration of suspensions containing very high particle concentration. For some applications, multi-wavelength ultrasound enhanced sedimentation filters are second only to the centrifuge in efficiency but, unlike the centrifuge they are easily adapted for continuous flow. Multi-wavelength resonators are also an obvious consideration when half-wavelength chambers are too small for a specific application. Unfortunately the formula, bigger = higher-throughput, does not scale linearly. Here we describe the relationships between chamber size and throughput for acoustic, electrical, flow and thermal convection actions, allowing the user to define initial parameters for their specific applications with some confidence. We start with a review of some of the many forms of multi-wavelength particle manipulation systems.
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Affiliation(s)
- Jeremy J Hawkes
- Manchester Institute of Biotechnology, The University of Manchester, 131 Princess Street, Manchester, M1 7DN, UK.
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Abstract
In part 21 of the tutorial series "Acoustofluidics--exploiting ultrasonic standing wave forces and acoustic streaming in microfluidic systems for cell and particle manipulation", we review applications of ultrasonic standing waves used for enhancing immunoassays and particle sensors. The paper covers ultrasonic enhancement of bead-based immuno-agglutination assays, bead-based immuno-fluorescence assays, vibrational spectroscopy sensors and cell deposition on a sensor surface.
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Affiliation(s)
- Martin Wiklund
- Dept. of Applied Physics, Royal Institute of Technology, SE 106 91 Stockholm, Sweden.
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Bruus H, Dual J, Hawkes J, Hill M, Laurell T, Nilsson J, Radel S, Sadhal S, Wiklund M. Forthcoming Lab on a Chip tutorial series on acoustofluidics: acoustofluidics-exploiting ultrasonic standing wave forces and acoustic streaming in microfluidic systems for cell and particle manipulation. Lab Chip 2011; 11:3579-80. [PMID: 21952310 DOI: 10.1039/c1lc90058g] [Citation(s) in RCA: 111] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
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9
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Palme O, Comanescu G, Stoineva I, Radel S, Benes E, Develter D, Wray V, Lang S. Sophorolipids from Candida bombicola: Cell separation by ultrasonic particle manipulation. EUR J LIPID SCI TECH 2010. [DOI: 10.1002/ejlt.200900163] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Radel S, Brandstetter M, Lendl B. Observation of particles manipulated by ultrasound in close proximity to a cone-shaped infrared spectroscopy probe. Ultrasonics 2010; 50:240-246. [PMID: 19883932 DOI: 10.1016/j.ultras.2009.09.030] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/10/2009] [Revised: 09/15/2009] [Accepted: 09/28/2009] [Indexed: 05/28/2023]
Abstract
The presented investigations aimed to enhance surface sensitive infrared spectroscopy for chemical analysis by ultrasonic particle manipulation. The combination of these techniques has the potential for new measurement concepts for use in the chemical analysis of suspensions. Local increases of particle concentration brought about by ultrasound could facilitate measurements of molecular-specific infrared spectra of the suspending phase and particles independently. By changing the frequency of an ultrasonic standing wave around 2 MHz it was possible to control the position of particles in respect to the optically sensitive region of the infrared spectroscope. Results obtained with a set-up that enabled us to explore the application of an ultrasonic standing wave to push suspended particles at or into mum distances of the sensing element of an in-line fiber optic probe and subsequently retract them from there are presented. Light micrographs suggested, that the task was successfully accomplished with polystyrene beads suspended in methanol, aggregates were manipulated to and from the cut surface of the truncated, cone-shaped fibre probe tip by changes of the ultrasonic frequency between 1.85 and 1.87 MHz. Feasibility was confirmed by infrared absorption spectra recorded when PTFE particles suspended in tetrahydrofuran were used.
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Affiliation(s)
- Stefan Radel
- Vienna University of Technology, Institute of Chemical Technologies and Analytics, Wiedner Hauptstr. 8-10/134, A-1040 Wien, Austria.
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Ruedas-Rama MJ, Domínguez-Vidal A, Radel S, Lendl B. Ultrasonic Trapping of Microparticles in Suspension and Reaction Monitoring Using Raman Microspectroscopy. Anal Chem 2007; 79:7853-7. [PMID: 17874849 DOI: 10.1021/ac071121l] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
An ultrasonic standing wave around 2 MHz has been used for trapping and concentration of suspended micrometer-size particles in a flow cell, whereas Raman microspectroscopy was used as a nondestructive technique to provide molecular information about the trapped particles. With this approach, detection and discrimination of different polymer microparticles based on their characteristic Raman spectra was performed. Dextran, poly(vinyl alcohol), and melamine resin-based beads, with and without functionalization, were used for this purpose. Furthermore, taking advantage of the flow-through characteristics of the cell and the versatility of the employed flow system, full control over the media surrounding the trapped particles was achieved. This allowed us to perform chemical reactions on the trapped particles and to monitor spectral changes in real time. Here retention of cation-exchanger beads loaded with silver ions and subsequent reduction of the silver ions was demonstrated. In this way, surface-enhanced Raman (SER) active beads were prepared and retained in the focus of the Raman microscope by means of the ultrasonic field. Injection of analytes in the flow system thus allowed recording of their SER spectra. Using 9-aminoacridine, a linear dependence of the found SER signal in the range from 1 to 10 microM has been achieved. The repeatability in the recorded SER intensities was on the order of 4-5%. This included bead retention, surface-enhanced Raman layer synthesis, and analyte detection.
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Affiliation(s)
- María José Ruedas-Rama
- Institute of Chemical Technologies and Analytics, Vienna University of Technology, Getreidemarkt 9/164AC, A-1060 Vienna, Austria
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Gherardini L, Cousins CM, Hawkes JJ, Spengler J, Radel S, Lawler H, Devcic-Kuhar B, Gröschl M, Coakley WT, McLoughlin AJ. A new immobilisation method to arrange particles in a gel matrix by ultrasound standing waves. Ultrasound Med Biol 2005; 31:261-72. [PMID: 15708466 DOI: 10.1016/j.ultrasmedbio.2004.10.010] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/13/2004] [Revised: 10/04/2004] [Accepted: 10/14/2004] [Indexed: 05/13/2023]
Abstract
Ultrasonic forces may be used to manipulate particles in suspension. For example, a standing wave ultrasound (US) field applied to a suspension moves the particles toward areas of minimal acoustic pressure, where they are orderly retained creating a predictable heterogeneous distribution. This principle of ultrasonic retention of particles or cells has been applied in numerous biotechnological applications, such as mammalian cell filtering and red blood cell sedimentation. Here, a new US-based cell immobilisation technique is described that allows manipulation and positioning of cells/particles within various nontoxic gel matrices before polymerisation. Specifically, gel immobilisation was used to directly demonstrate that the viability of yeast cells arranged by an US standing wave is maintained up to 4 days after treatment. The versatility of this immobilisation method was validated using a wide range of acoustic devices. Finally, the potential biotechnological advantages of this US-controlled particle positioning method combined with gel immobilisation/encapsulation technology are discussed.
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Affiliation(s)
- Lisa Gherardini
- Department of Industrial Microbiology, University College Dublin, Belfield, Dublin, Ireland
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Gherardini L, Radel S, Sielemann S, Doblhoff-Dier O, Gröschl M, Benes E, McLoughlin AJ. A study of the spatial organisation of microbial cells in a gel matrix subjected to treatment with ultrasound standing waves. Bioseparation 2002; 10:153-62. [PMID: 12233739 DOI: 10.1023/a:1016311410219] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Retention and manipulation of microbial cells through exploitation of ultrasonic forces has been reported as a novel cell immobilisation technique. The spatial ordering of yeast cells, within suspensions subjected to an ultrasonic standing wave field, was analysed for the first time. A technique, based on 'freezing' the spatial arrangement using polymer gelation was developed. The resultant gel was then sectioned and examined using microscopic techniques. Light Microscopy confirmed the presence of specific regions in the ultrasonic field, where the cells are organised into bands corresponding to the standing waves' pressure nodal planes. Computer Image Analysis measurement of several physical parameters associated with this cell distribution matched the values derived from the theoretical model. The spatial cell-cell re-arrangement within each band and uneven distribution along the nodal planes have been analysed by Scanning Electron Microscopy. These results complement the ongoing study of the process of immobilisation of microbial cells by ultrasound standing waves.
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Affiliation(s)
- L Gherardini
- Institute of Applied Microbiology, University of Agricultural Sciences, Vienna, Austria.
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Radel S, Gherardini L, McLoughlin AJ, Doblhoff-Dier O, Benes E. Breakdown of immobilisation/separation and morphology changes of yeast suspended in water-rich ethanol mixtures exposed to ultrasonic plane standing waves. Bioseparation 2001; 9:369-77. [PMID: 11518240 DOI: 10.1023/a:1011158019835] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Some physiological/morphological changes have been reported before, when suspended yeasts have been irradiated with well-defined ultrasonic standing, as well as propagating, plane waves around 2.2 MHz, as used in ultrasonic coagulation, e.g., for cell filtering. Thus we used yeast as a biological model to explore the reasons for both those morphology changes and some unusual macroscopic behaviour in the case of water-rich ethanol mixtures when used as carrier liquid. When the cells were suspended in 12% (v/v) ethanol-water mixture separation was greatly reduced; the yeast cells were not retained in the pressure nodal planes of the standing wave, but mixed turbulently through the separation system. How this behaviour alters the efficiency of retention/immobilisation was measured. As the viability of the yeast was decreased as well the morphology of the cells was examined using transmission electron microscopy. Two effects, according to the type of assessment, were evident; a disruption of the cells vacuole and also damage to the cell wall/membrane complex. The extent of the alterations in vacuole structure with sonication time, utilising a fluorescent vacuole membrane dye, was measured. Transient cavitation was not detected and thus could be excluded as being responsible for the observed effects. Other possible reasons for the disruption of the intracellular compartments may be acoustic pressure, displacement or other, secondary effects like (sub) harmonic cavitation. The investigations contribute to a better understanding of the physical conditions experienced when a cell is stressed in a high-frequency ultrasonic wave in the MHz range.
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Affiliation(s)
- S Radel
- University College Dublin, Department of Industrial Microbiology, Dublin, Ireland.
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Radel S, McLoughlin AJ, Gherardini L, Doblhoff-Dier O, Benes E. Viability of yeast cells in well controlled propagating and standing ultrasonic plane waves. Ultrasonics 2000; 38:633-7. [PMID: 10829741 DOI: 10.1016/s0041-624x(99)00211-5] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Recent studies have shown that there is no loss of cell viability when the cells are subjected to ultrasonic standing wave fields in acoustic cell retention systems. These systems are characterised by waves that spatially vary in pressure amplitude in the direction of sound propagation. In this work an anechoic 'one-dimensional' sonication chamber has been developed that produces propagating waves, which differ from standing waves in that the pressure amplitude remains constant as the wave travels in a medium with negligible attenuation. The viability of yeast cell suspensions as a function of treatment time was investigated during exposure to both standing and propagating wave fields with frequencies slightly above 2 MHz. The influence of 12% (vol/vol) of ethanol in water on the spatial arrangement of the cells in suspension was also studied. Changes in yeast cell morphology caused by the different types of suspension media and the ultrasonic treatment were examined by transmission electron microscopy (TEM). The agglomeration of yeast cells within the pressure nodal planes appears to minimise damaging effects due to ultrasonic fields.
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Affiliation(s)
- S Radel
- Department of Industrial Microbiology, University College Dublin, Ireland.
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Abstract
The ATCC type strain and six clinical isolates of Campylobacter rectus were tested for toxicity against HL-60 cells and human polymorphonuclear neutrophils (PMNs). After challenge with bacterial cell suspensions and media supernatants for up to 4 h, eukaryotic cell viability was assayed by trypan blue dye exclusion and lactate dehydrogenase release. Cells of the C. rectus type strain were not toxic. However, ethanol and (NH4)2SO4 extracts of culture media supernatants killed HL-60 cells in a time and dose dependent manner with 700 micrograms of supernatant protein killing 100% of HL-60 cells in 4 h. Concentrated media supernatants from clinical isolates also killed 100% of HL-60 cells in 30 to 60 min. The bacterial culture supernatants were toxic to PMNs with clinical isolates killing 70 to 90% of PMNs in 2 to 4 h. SDS-PAGE and immunoblot analysis of the toxic media supernatants revealed C. rectus specific proteins and lipopolysaccharide (LPS). The toxic activity was inhibited by protease, indicating that the toxin was protein. Non-toxic and toxic media supernatants were obtained by altering hemin and fumarate in the growth media. SDS-PAGE analysis of these revealed that all toxic supernatants contained a 104 kDa protein.
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Affiliation(s)
- J Gillespie
- Department of Oral Biology, State University of New York, Buffalo 14214
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Radel S, Fredericks W, Mayhew E, Baker R. P-glycoprotein expression and modulation of cell-membrane morphology in adriamycin-resistant P388 leukemia cells. Cancer Chemother Pharmacol 1990; 25:241-6. [PMID: 1967228 DOI: 10.1007/bf00684879] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Electron microscopy of cultured P388 leukemia cells revealed morphological differences between the Adriamycin-resistant (P388/ADR) and -sensitive (P388/0) cell lines. P388/ADR cells showed longer villus-like protrusions and large foldings of the plasma cell membrane, whereas P388/0 cells had only short membrane protrusions. Western blot analysis of cells revealed the increased expression of a glycoprotein of 170-180 kDa (P-glycoprotein) in P388/ADR cells as compared with P388/0 cells, which is consistent with the findings of other studies. A modulation of the membrane morphology of in vitro P388/ADR cells was evident from one i.p. in vivo passage for 10 days, by a reversion to the non-ruffled sensitive-cell morphology. Long-term P388/ADR culture cells showed a reduction in membrane folding with as little as a 4-h exposure to the peritoneal ascitic fluid obtained when the tumor was harvested. However, there was no alteration in the expression of P-glycoprotein or in the sensitivity to Adriamycin in either of the P388 cell lines when grown in vivo or when exposed to ascites fluid from an i.p. tumor. Thus, the modulation of membrane morphology was related to the tumor cell environment rather than the abundance of P-glycoprotein in the plasma membrane.
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Affiliation(s)
- S Radel
- Department of Oral Biology, State University of New York, Buffalo 14214
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Radel S, Bankusli I, Mayhew E, Rustum YM. The effects of verapamil and a tiapamil analogue, DMDP, on adriamycin-induced cytotoxicity in P388 adriamycin-resistant and -sensitive leukemia in vitro and in vivo. Cancer Chemother Pharmacol 1988; 21:25-30. [PMID: 3342462 DOI: 10.1007/bf00262733] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
DMDP [N-(3,4-dimethoxyphenethyl)-N-methyl-2-(2-naphthyl-m-dithane- 2-propylamine] a recently developed calcium antagonist analogue, caused a greatly increased intracellular retention of adriamycin and concomitant enhanced cytotoxicity in adriamycin-resistant P388 leukemia cells in vitro. These effects of DMDP were greater than those of another calcium channel blocker, verapamil, and occurred at one-half the dosage levels. Only slight enhancement in adriamycin toxicity was observed for either of these agents in the adriamycin-sensitive parental cell line. However, no significant therapeutic potentiation of adriamycin activity occurred with either verapamil or DMDP treatment in vivo. In vivo maximum DMDP tumor intracellular concentrations, as analyzed by HPLC, were the same in vitro tumor cell levels required to overcome adriamycin resistance. This inability to overcome drug resistance in vivo at acceptable levels of host toxicity is not only a function of maintaining necessary calcium antagonist concentrations in resistant tumor cells.
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Affiliation(s)
- S Radel
- Department of Experimental Pathology, Roswell Park Memorial Institute, Buffalo, NY 14263
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Radel S, Mayhew E, Rustum YM. Effects of DMDP, a tiapamil analogue, on adriamycin efflux in adriamycin-resistant and -sensitive P388 cells. Anticancer Res 1987; 7:1105-8. [PMID: 3442407] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
The calcium channel blockers 'DMDP' [N-3,4-dimethoxyphenethyl)-N-methyl-2-(2-naphthyl-m-dithane-2-prop ylamine)] and verapamil inhibited the active efflux of adriamycin from adriamycin-resistant P388 leukemia cells but had no effect on the drug-sensitive cell line. However, after removal of the calcium channel blockers, DMDP at a low drug concentration caused a much longer inhibition of this efflux pathway than verapamil. This may be attributed to the higher binding affinity of DMDP for receptor sites.
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Affiliation(s)
- S Radel
- Department of Experimental Pathology, Roswell Park Memorial Institute, Buffalo, N.Y. 14263
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