1
|
Pan Y, Jiang D, Gu C, Qiu Y, Wan H, Wang P. 3D microgroove electrical impedance sensing to examine 3D cell cultures for antineoplastic drug assessment. MICROSYSTEMS & NANOENGINEERING 2020; 6:23. [PMID: 34567638 PMCID: PMC8433334 DOI: 10.1038/s41378-020-0130-x] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2019] [Revised: 10/25/2019] [Accepted: 11/10/2019] [Indexed: 05/19/2023]
Abstract
In recent decades, three-dimensional (3D) cancer cell models have attracted increasing interest in the field of drug screening due to their significant advantages in more accurate simulations of heterogeneous tumor behavior in vivo compared to two-dimensional models. Furthermore, drug sensitivity testing based on 3D cancer cell models can provide more reliable in vivo efficacy prediction. The gold standard fluorescence staining is hard to achieve real-time and label-free viability monitoring in 3D cancer cell models. In this study, a microgroove impedance sensor (MGIS) was specially developed for the dynamic and noninvasive monitoring of 3D cell viability. 3D cancer cells were trapped in microgrooves with gold electrodes on opposite walls for in situ impedance measurement. The change in the number of live cells caused inversely proportional changes to the impedance magnitude of the entire cell/Matrigel construct and reflected the proliferation and apoptosis of the 3D cells. It was confirmed that the 3D cell viability detected by the MGIS was highly consistent with the standard live/dead staining by confocal microscope characterization. Furthermore, the accuracy of the MGIS was validated quantitatively using a 3D lung cancer model and sophisticated drug sensitivity testing. In addition, the parameters of the MGIS in the measurement experiments were optimized in detail using simulations and experimental validation. The results demonstrated that the MGIS coupled with 3D cell culture would be a promising platform to improve the efficiency and accuracy of cell-based anticancer drug screening in vitro.
Collapse
Affiliation(s)
- Yuxiang Pan
- Biosensor National Special Laboratory, Key Laboratory for Biomedical Engineering of Education Ministry, Department of Biomedical Engineering, Zhejiang University, Hangzhou, 310027 China
- State Key Laboratory of Transducer Technology, Chinese Academy of Sciences, Shanghai, 200050 China
| | - Deming Jiang
- Biosensor National Special Laboratory, Key Laboratory for Biomedical Engineering of Education Ministry, Department of Biomedical Engineering, Zhejiang University, Hangzhou, 310027 China
| | - Chenlei Gu
- Biosensor National Special Laboratory, Key Laboratory for Biomedical Engineering of Education Ministry, Department of Biomedical Engineering, Zhejiang University, Hangzhou, 310027 China
| | - Yong Qiu
- Biosensor National Special Laboratory, Key Laboratory for Biomedical Engineering of Education Ministry, Department of Biomedical Engineering, Zhejiang University, Hangzhou, 310027 China
| | - Hao Wan
- Biosensor National Special Laboratory, Key Laboratory for Biomedical Engineering of Education Ministry, Department of Biomedical Engineering, Zhejiang University, Hangzhou, 310027 China
- State Key Laboratory of Transducer Technology, Chinese Academy of Sciences, Shanghai, 200050 China
| | - Ping Wang
- Biosensor National Special Laboratory, Key Laboratory for Biomedical Engineering of Education Ministry, Department of Biomedical Engineering, Zhejiang University, Hangzhou, 310027 China
- State Key Laboratory of Transducer Technology, Chinese Academy of Sciences, Shanghai, 200050 China
| |
Collapse
|
2
|
Pan Y, Hu N, Wei X, Gong L, Zhang B, Wan H, Wang P. 3D cell-based biosensor for cell viability and drug assessment by 3D electric cell/matrigel-substrate impedance sensing. Biosens Bioelectron 2019; 130:344-351. [DOI: 10.1016/j.bios.2018.09.046] [Citation(s) in RCA: 64] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2018] [Revised: 08/30/2018] [Accepted: 09/12/2018] [Indexed: 12/11/2022]
|
3
|
Buckner CA, Buckner AL, Koren SA, Persinger MA, Lafrenie RM. The effects of electromagnetic fields on B16-BL6 cells are dependent on their spatial and temporal character. Bioelectromagnetics 2016; 38:165-174. [DOI: 10.1002/bem.22031] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2016] [Accepted: 12/07/2016] [Indexed: 12/20/2022]
Affiliation(s)
- Carly A. Buckner
- Department of Biomolecular Sciences; Laurentian University; Sudbury Ontario Canada
- Regional Cancer Program; Sudbury Regional Hospital; Sudbury Ontario Canada
| | - Alison L. Buckner
- Department of Biomolecular Sciences; Laurentian University; Sudbury Ontario Canada
- Regional Cancer Program; Sudbury Regional Hospital; Sudbury Ontario Canada
| | - Stan A. Koren
- Department of Behavioural Neuroscience; Laurentian University; Sudbury Ontario Canada
| | - Michael A. Persinger
- Department of Biomolecular Sciences; Laurentian University; Sudbury Ontario Canada
- Department of Behavioural Neuroscience; Laurentian University; Sudbury Ontario Canada
| | - Robert M. Lafrenie
- Department of Biomolecular Sciences; Laurentian University; Sudbury Ontario Canada
- Regional Cancer Program; Sudbury Regional Hospital; Sudbury Ontario Canada
- Northern Ontario School of Medicine; Sudbury Ontario Canada
| |
Collapse
|
4
|
Aliyev RM, Geiger G. Cell-stimulation therapy of lateral epicondylitis with frequency-modulated low-intensity electric current. Bull Exp Biol Med 2012; 152:653-5. [PMID: 22803157 DOI: 10.1007/s10517-012-1599-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
In addition to the routine therapy, the patients with lateral epicondylitis included into experimental group were subjected to a 12-week cell-stimulation therapy with low-intensity frequency-modulated electric current. The control group received the same routine therapy and sham stimulation (the therapeutic apparatus was not energized). The efficiency of this microcurrent therapy was estimated by comparing medical indices before therapy and at the end of a 12-week therapeutic course using a 10-point pain severity numeric rating scale (NRS) and Roles-Maudsley pain score. The study revealed high therapeutic efficiency of cell-stimulation with low-intensity electric current resulting probably from up-regulation of intracellular transmitters, interleukins, and prostaglandins playing the key role in the regulation of inflammation.
Collapse
Affiliation(s)
- R M Aliyev
- Orthopedics and Traumatology Clinics, Bethlehem Hospital, Stolberg, Germany.
| | | |
Collapse
|
5
|
Jeong SH, Lee DW, Kim S, Kim J, Ku B. A study of electrochemical biosensor for analysis of three-dimensional (3D) cell culture. Biosens Bioelectron 2012; 35:128-133. [PMID: 22410483 DOI: 10.1016/j.bios.2012.02.039] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2011] [Revised: 02/07/2012] [Accepted: 02/15/2012] [Indexed: 01/23/2023]
Abstract
Cell culture has a fundamental role not only in regenerative medicine but also in biotechnology, pharmacology, impacting both drug discovery and manufacturing. Although cell culture has been generally developed for only two-dimensional (2D) culture systems, three-dimensional (3D) culture is being spotlighted as the means to mimic in vivo cellular conditions. In this study, a method for cytotoxicity assay using an electrochemical biosensor applying 3D cell culture is presented. In order to strengthen the advantage of a 3D cell culture, the experimental condition of gelation between several types of sol-gels (alginate, collagen, matrigel) and cancer cells can be optimized to make a 3D cell structure on the electrode, which will show the reproducibility of electrical measurement for long-term monitoring. Moreover, cytotoxicity test results applying this method showed IC(50) value of A549 lung cancer cells to erlotinib. Thus, this study evaluates the feasibility of application of the electrochemical biosensor for 3D cell culture to cytotoxicity assay for investigation of 3D cell response to drug compounds.
Collapse
Affiliation(s)
- Se Hoon Jeong
- Advanced Materials & Devices Lab, Corporate R&D Institute, Samsung Electro-Mechanics Co., Ltd., Suwon 443-743, Republic of Korea.
| | - Dong Woo Lee
- Advanced Materials & Devices Lab, Corporate R&D Institute, Samsung Electro-Mechanics Co., Ltd., Suwon 443-743, Republic of Korea
| | - Sanghyo Kim
- College of Bionano technology, Gachon University, Seongnam 461-701, Republic of Korea
| | - Jhingook Kim
- Samsung Medical Center, School of Medicine, Sungkyunkwan University, Seoul 135-230, Republic of Korea
| | - Bosung Ku
- Advanced Materials & Devices Lab, Corporate R&D Institute, Samsung Electro-Mechanics Co., Ltd., Suwon 443-743, Republic of Korea.
| |
Collapse
|
6
|
Docoslis A, Kalogerakis N, Behie LA. Dielectrophoretic forces can be safely used to retain viable cells in perfusion cultures of animal cells. Cytotechnology 2011; 30:133-42. [PMID: 19003362 DOI: 10.1023/a:1008050809217] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Dielectrophoresis is a well established and effective means for the manipulation of viable cells. However, its effectiveness greatly depends upon the utilization of very low electrical conductivity media. High conductivity media, as in the case of cell culture media, result only in the induction of weaker repulsive forces (negative dielectrophoresis) and excessive medium heating. A dielectrophoresis-based cell separation device (DEP-filter) has been recently developed for perfusion cultures that successfully overcomes these obstacles and provides a very high degree of viable cell separation while most of the nonviable cells are removed from the bioreactor by the effluent stream. The latter results in high viabilities throughout the culture period and minimization of lysed cell proteases in the bioreactor. However, an important question that remains to be answered is whether we have any adverse effects by exposing the cultured cells to high frequency electric fields for extended periods of time. A special chamber was constructed to quantitate the effect under several operational conditions. Cell growth, glucose uptake, lactate and monoclonal antibody production data suggest that there is no appreciable effect and hence, operation over long periods of time of the DEP-filter should not have any adverse effect on the cultured cells.
Collapse
Affiliation(s)
- A Docoslis
- Bioengineering Laboratory, Department of Chemical Engineering, State University of New York, Buffalo, NY, 14260, USA
| | | | | |
Collapse
|
7
|
Li J, Chang WH, Jan HW, Ruaan RC, Liu HC, Sun J. Optimum Parameters of Specific 7.5 Hz Single Pulsed Electromagnetic Field Stimulation on Osteoblast Growth. Electromagn Biol Med 2009. [DOI: 10.1081/jbc-120024619] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
|
8
|
Köbbert C, Berndt A, Bierbaum T, Sontag W, Breithardt G, Weissen-Plenz G, Sindermann JR. Low-energy electromagnetic fields promote proliferation of vascular smooth muscle cells. Electromagn Biol Med 2008; 27:41-53. [PMID: 18327713 DOI: 10.1080/15368370701878929] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
The rationale was to investigate the effects of low-energy electromagnetic fields (EMF) on the proliferation of bovine coronary and murine aortic smooth muscle cells (SMC). EMF were applied to SMC at field frequencies of 25, 50, or 100 Hz, and exposure time was set to 5, 15, or 30 minutes. Significant increases in SMC-counts compared with sham exposed controls were found for all EMF-frequencies tested. The effect was most pronounced for 50 Hz fields with maximum increases of 1.2-fold over controls. Sequential double exposure of mouse aortic SMC to 50 Hz fields revealed significantly enhanced cell proliferation by 1.2 fold compared with single exposure (p < 0.05). Experiments performed on bovine SMC also revealed significant increases in cell proliferation. The results demonstrate that EMF are capable of significantly enhancing the proliferation of vascular SMC. These results rise the question whether EMF would qualify as supportive means to angio-/arteriogenic approaches.
Collapse
Affiliation(s)
- Christiane Köbbert
- Department of Cardiology and Angiology, Hospital of the University of Münster, Münster, Germany
| | | | | | | | | | | | | |
Collapse
|
9
|
Sontag W, Kalka D. Repetitive transcranial magnetic stimulation does not influence immunological HL-60 cells and neuronal PC12 cells. Int J Radiat Biol 2007; 83:603-15. [PMID: 17654102 DOI: 10.1080/09553000701481766] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
BACKGROUND Transcranial magnetic stimulation (TMS) is a non-invasive method used in medical applications such as brain mapping or as a therapeutic tool in neurological and psychiatric disorders because it can stimulate defined regions of the brain without anaesthesia. METHODS The action of repetitive transcranial magnetic stimulation (rTMS) on HL-60 and PC12 cells has been investigated. The cells have been stimulated in vitro with different number of pulses (75 - 1250), different intensities (10, 20 and 40%) and different frequencies (0.25, 1 and 10 Hz) by using a double coil (2x70 mm) connected to the 'Magstim rapid'. At selected time points after treatment the following endpoints have been determined: viability, cyclic AMP (cAMP) and heat shock protein 72 (Hsp72) (HL-60 cells), and viability, cAMP, dopamine and noradrenaline (PC12 cells). Viability was measured with the alamarBlue assay, whereas cAMP, Hsp72, dopamine and noradrenaline were determined with enzyme-linked immunosorbent assay (ELISA). RESULTS In both cell lines viability was not influenced by rTMS treatment, the same was true for the cytosolic cAMP concentration. In HL-60 cells rTMS treatment did not change the Hsp72 content, also a protective effect of rTMS treatment on cell viability before toxic H(2)O(2) treatment was not observed. After high potassium treatment the release of the two neurotransmitters dopamine and noradrenaline in PC12 cells was enhanced 15- and 5-fold, respectively, but after rTMS treatment no change in the release of the two neurotransmitters was observed. CONCLUSIONS In two mammalian cell lines rTMS treatment in a variety of exposure conditions does not influence any of the measured parameters.
Collapse
Affiliation(s)
- Werner Sontag
- Forschungszentrum Karlsruhe, Institut für Biologische Grenzflächen, Postfach, Karlsruhe, Germany.
| | | |
Collapse
|
10
|
Sontag W, Weibezahn KF. IL-8 release of HL-60 cells treated with electric currents of different wave forms. Electromagn Biol Med 2007; 26:191-205. [PMID: 17886006 DOI: 10.1080/15368370701572738] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
Human promyelocytic leukaemia HL-60 cells which have been differentiated by DMSO to granulocytes were used to investigate the effect of different waveforms on the release of interleukine-8 (IL-8). The cells were prestimulated with 100 pM fMLP and subsequently treated for 15 min with different electrical fields and currents. Three hours later the release of IL-8 into the medium was determined by ELISA. Varying the frequency of the sinusoidal electrical current between 0 and 20 Hz resulted in 2 maxima of IL-8 release at 5 and 13 Hz. Prestimulated cells were treated with sine-, triangular-, and rectangular-waveforms at 5 Hz in the current intensity range of 0-3 mA/cm(2). For the three waveforms tested, the IL-8 release was enhanced 1.5 fold. Treatment of the cells with capacitively coupled electric fields of 5 Hz using field strengths between 0 and 10 V(eff)/cm had no effect on the release of IL-8. In comparison to the positive results after sine wave exposure alone, an exposure with sine wave current to which noise had been superimposed had no effect on the HL-60 cells. From these investigations it can be concluded that for electrical current treatment of prestimulated HL-60 cells the release of IL-8 does not depend on the waveform if the waveform information is not destroyed by superimposed noise.
Collapse
Affiliation(s)
- Werner Sontag
- Forschungszentrum Karlsruhe, Institut für Biologische Grenzflächen, Karlsruhe, Germany.
| | | |
Collapse
|
11
|
Sontag W, Kalka D. No effect of pulsed electromagnetic fields on PC12 and HL-60 cells. RADIATION AND ENVIRONMENTAL BIOPHYSICS 2006; 45:63-71. [PMID: 16625396 DOI: 10.1007/s00411-006-0043-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/23/2005] [Accepted: 03/11/2006] [Indexed: 05/08/2023]
Abstract
The effect of pulsed electromagnetic fields (PEMF) similar to those used in transcranial magnetic stimulation (TMS) on two tumour cell lines, the human promyelocytic leukaemia cell line (HL-60) and the rat pheochromocytoma cell line (PC12), was investigated. The two cell lines were exposed to non-homogeneous pulsed electromagnetic fields (about 0.25-4.5 T peak magnetic field strength; 1-8 exponential pulses, 0.25 Hz) at different positions on the coil (2x25 mm). After exposure with various intensities, various numbers of pulses and at different coil positions, cell viability and the intracellular cyclic AMP content were determined in the two cell lines. Additionally, in HL-60 cells the intracellular Hsp72 content and in PC12 cells the release of the neurotransmitters dopamine, noradrenaline and acetylcholine were measured after PEMF treatment. The results of these analyses do not hint at alterations in the cell viability or in the content of cAMP, Hsp72, dopamine, noradrenaline, and acetylcholine in the two tumour cell lines after PEMF exposure under various conditions.
Collapse
Affiliation(s)
- W Sontag
- Forschungszentrum Karlsruhe, Institut für Biologische Grenzflächen, Postfach 3640, 76021 Karlsruhe, Germany.
| | | |
Collapse
|
12
|
Kilgore KL, Bhadra N. Nerve conduction block utilising high-frequency alternating current. Med Biol Eng Comput 2004; 42:394-406. [PMID: 15191086 DOI: 10.1007/bf02344716] [Citation(s) in RCA: 187] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
High-frequency alternating current (AC) waveforms have been shown to produce a quickly reversible nerve block in animal models, but the parameters and mechanism of this block are not well understood. A frog sciatic nerve/gastrocnemius muscle preparation was used to examine the parameters for nerve conduction block in vivo, and a computer simulation of the nerve membrane was used to identify the mechanism for block. The results indicated that a 100% block of motor activity can be accomplished with a variety of waveform parameters, including sinusoidal and rectangular waveforms at frequencies from 2 kHz to 20 kHz. A complete and reversible block was achieved in 34 out of 34 nerve preparations tested. The most efficient waveform for conduction block was a 3-5 kHz constant-current biphasic sinusoid, where block could be achieved with stimulus levels as low as 0.01 microCphase(-1). It was demonstrated that the block was not produced indirectly through fatigue. Computer simulation of high-frequency AC demonstrated a steady-state depolarisation of the nerve membrane, and it is hypothesised that the conduction block was due to this tonic depolarisation. The precise relationship between the steady-state depolarisation and the conduction block requires further analysis. The results of this study demonstrated that high-frequency AC can be used to produce a fast-acting, and quickly reversible nerve conduction block that may have multiple applications in the treatment of unwanted neural activity.
Collapse
Affiliation(s)
- K L Kilgore
- MetroHealth Medical Center, Cleveland, Ohio, USA.
| | | |
Collapse
|
13
|
Sontag W. Response of cyclic AMP by DMSO differentiated HL-60 cells exposed to electric interferential current after prestimulation. Bioelectromagnetics 2004; 25:176-84. [PMID: 15042626 DOI: 10.1002/bem.10183] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
The action of interferential current (IFC) upon intracellular content of cyclic adenosine monophosphate (cAMP) after prestimulation with the chemotactic peptide N-formyl-methionyl-leucyl-phenylalanine (fMLP) has been investigated. Human promyelocytes (HL-60) differentiated to granulocytes by dimethylsulphoxide (DMSO) have been treated with different concentrations of fMLP. This enhances their cAMP content. The half maximal effective concentration (EC50) was about 4 nM. Exposure to IFC with modulation frequencies of 35 and 125 Hz (5 min, 250 microA/cm2) after prestimulation with various concentrations of fMLP had no enhancing effect at low or high concentrations of fMLP. In contrast, at medium concentrations in the range of about 100 pM fMLP, a significant enhancement of cAMP could be observed. This synergistic effect of fMLP and IFC has been examined in detail by varying the modulation frequency, current density, and exposure time. Enhancement of cAMP content could be observed at certain modulation frequencies and exposure times suggesting a window effect, whereas for the current density in the range measured (8.5 microA/cm2-2.5 mA/cm2) a constant enhancement could be observed. The synergistic effect of fMLP and IFC could only be observed in the treatment sequence of fMLP followed by IFC; an inverse sequence had no effect on the cAMP content. .
Collapse
Affiliation(s)
- W Sontag
- Forschungszentrum Karlsruhe, Institut für Medizintechnik und Biophysik, Karlsruhe, Germany.
| |
Collapse
|
14
|
Gottwald E, Wobus AM, Guan K, Sontag W, Weibezahn KF, Dertinger H. INTERFERENTIAL ELECTRIC FIELD TREATMENT REVEALED A LOW INCREASE OF SPONTANEOUS CARDIAC DIFFERENTIATION BUT NO CYCLIC AMP CHANGES NOR INDUCTION OF CARDIAC-SPECIFIC GENE EXPRESSION IN PLURIPOTENT EMBRYONAL CARCINOMA P19 CELLS. Electromagn Biol Med 2002. [DOI: 10.1081/jbc-120006783] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
|
15
|
Sontag W, Weibezahn KF. INFLUENCE OF LOW-FREQUENCY ELECTRIC FIELDS ON PROLIFERATION AND IL-8 RELEASE OF HL-60 CELLS. Electromagn Biol Med 2002. [DOI: 10.1081/jbc-120006784] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
|
16
|
Burlon O, Weibezahn K, Gottwald E, Winterhager E. INTERFERENTIAL ELECTRIC FIELDS REVEAL NONUNIFORM EFFECTS ON PROLIFERATION AND hCG SECRETION IN JAr CELLS. Electromagn Biol Med 2002. [DOI: 10.1081/jbc-120006785] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
|
17
|
Abstract
Proliferation of SV40-3T3 mouse fibroblasts and human HL-60 promyelocytes was studied after treatment with a sinusoidal 2 mT 50 Hz magnetic field. A single exposure of 60 minutes caused quasicyclic changes in the number of SV40-3T3 cultures as function of time after treatment, which was interpreted to be due to the induction of chronobiological mechanisms by the field. Moreover, small variations in cell cycle distribution were measured during postexposure incubation for both cell lines. To discriminate between the effect of the magnetic vector and the induced electric field, HL-60 cell exposure was also performed on organ culture dishes. These dishes consist of two coaxially centered, isolated compartments in which different electric field levels are induced in the medium during treatment. Cell growth was affected in the outer compartment only where the induced electric field ranged from 8 to 12 mVpeak/meter at 2 mT, but it was not affected in the inner compartment (field range 0-4 mVpeak/meter). This suggests that the effects on cell growth are due to the induced electric field and are expressed only above a threshold of between 4 and 8 mVpeak/meter.
Collapse
Affiliation(s)
- J Schimmelpfeng
- Forschungszentrum Karlsruhe, Institut für Toxikologie, Germany
| | | |
Collapse
|
18
|
Sontag W. Action of extremely low frequency electric fields on the cytosolic calcium concentration of differentiated HL-60 cells: nonactivated cells. Bioelectromagnetics 2000; 19:32-40. [PMID: 9453704 DOI: 10.1002/(sici)1521-186x(1998)19:1<32::aid-bem3>3.0.co;2-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The effect of sinusoidal electric fields on the cytosolic free [Ca2+]i concentration in differentiated HL-60 cells was measured. The calcium concentration was measured in a fluorescence spectrometer using the fluorescence sample fluo-3. In the fluorescence spectrometer two samples can be measured simultaneously, one as the sham-exposed control and the other as the field-exposed sample. The effects of an external field, applied using two capacitor plates outside the cuvettes, and a field applied directly to the medium, using two platinum electrodes inside the cuvettes, were measured at selected frequencies between 0 and 100 Hz and field strengths from 1 to 2000 Vpp/m (external field) and from 0.1 to 1000 Vpp/m (in medium). No significant effects of the fields on the cytosolic free [Ca2+]i concentration in HL-60 cells have been observed at the measured frequencies and field strengths.
Collapse
Affiliation(s)
- W Sontag
- Forschungszentrum Karlsruhe, Institut für Toxikologie, Germany.
| |
Collapse
|
19
|
Ramstad S, Futsaether CM, Johnsson A. Effects of 50 Hz electric currents and magnetic fields on the prokaryotePropionibacterium acnes. Bioelectromagnetics 2000. [DOI: 10.1002/(sici)1521-186x(200005)21:4<302::aid-bem6>3.0.co;2-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
|
20
|
Abstract
The influence of interferential current (IFC) on the release of four cytokines was investigated. IFC is an amplitude-modulated 4 kHz current used in therapeutic applications. Human promyelocytes (HL-60) were differentiated to monocytes/macrophages by treatment with calcitriol. Release of tumor necrosis factor alpha (TNFalpha) and interleukines 1beta, 6, and 8 (IL-1beta, IL-6, and IL-8) into the supernatant was measured after exposure to IFC at different modulation frequencies. TNFalpha release was stimulated about twofold by 4 kHz sine waves alone. The influences of exposure time (5-30 min) and current density (2.5-2500 microA/c m(2)) were tested. A maximum field effect was found at an exposure time of 15 min and a current density of 250 microA/cm(2). With these exposure conditions (15 min and 250 microA/cm(2) ), cells were treated at different modulation frequencies and reacted for TNFalpha, IL-1beta, and IL-8 release in a complex manner. Within the frequencies studied (0-125 Hz), we found stimulation as well as depression of the release. In a second run the cells were activated by pretreatment with 10 microg/ml lipopolysaccharide (LPS) and exposed in the same way as the nonactivated cells. Again the modulation frequency influenced, in a complex way, the induction of TNFalpha, IL-1beta, and IL-8, resulting in a pattern of stimulation and depression of release different from that found in nonactivated cells. For IL-6 production no significant changes were detected in activated or non-activated cells.
Collapse
Affiliation(s)
- W Sontag
- Forschungszentrum Karlsruhe Institut für Toxikologie, Federal Republic of Germany.
| |
Collapse
|
21
|
Sch�nborn F, Pokovi? K, Wobus AM, Kuster N. Design, optimization, realization, and analysis of an in vitro system for the exposure of embryonic stem cells at 1.71 GHz. Bioelectromagnetics 2000. [DOI: 10.1002/1521-186x(200007)21:5<372::aid-bem6>3.0.co;2-s] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
|
22
|
Fear EC, Stuchly MA. Modeling assemblies of biological cells exposed to electric fields. IEEE Trans Biomed Eng 1998; 45:1259-71. [PMID: 9775540 DOI: 10.1109/10.720204] [Citation(s) in RCA: 65] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Gap junctions are channels through the cell membrane that electrically connect the interiors of neighboring cells. Most cells are connected by gap junctions, and gaps play an important role in local intercellular communication by allowing for the exchange of certain substances between cells. Gap communication has been observed to change when cells are exposed to electromagnetic (EM) fields. In this work, we examine the behavior of cells connected by gap junctions when exposed to electric fields, in order to better understand the influence of the presence of gap junctions on cell behavior. This may provide insights into the interactions between biological cells and weak, low-frequency EM fields. Specifically, we model gaps in greater detail than is usually the case, and use the finite element method (FEM) to solve the resulting geometrically complex cell models. The responses of gap-connected cell configurations to both dc and time harmonic fields are investigated and compared with those of similarly shaped (equivalent) cells. To further assess the influence of the gap junctions, properties such as gap size, shape, and conductivity are varied. Our findings indicate that simple models, such as equivalent cells, are sufficient for describing the behavior of small gap-connected cell configurations exposed to dc electric fields. With larger configurations, some adjustments to the simple models are necessary to account for the presence of the gaps. The gap junctions complicate the frequency behavior of gap-connected cell assemblies. An equivalent cell exhibits low-pass behavior. Gaps effectively add a bandstop filter in series with the low-pass behavior, thus lowering the relaxation frequency. The characteristics of this bandstop filter change with changes to gap properties. Comparison of the FEM results to those obtained with simple models indicates that more complex models are required to represent gap-connected cells.
Collapse
Affiliation(s)
- E C Fear
- Department of Electrical and Computer Engineering, University of Victoria, BC, Canada.
| | | |
Collapse
|
23
|
Sontag W. Treatment of zymosan-activated HL-60 cells with low frequencies electric fields does not change cellular ATP and ADP levels and reactive oxygen species. ACTA ACUST UNITED AC 1998. [DOI: 10.1016/s0302-4598(98)00150-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
24
|
Fear EC, Stuchly MA. Biological cells with gap junctions in low-frequency electric fields. IEEE Trans Biomed Eng 1998; 45:856-66. [PMID: 9644894 DOI: 10.1109/10.686793] [Citation(s) in RCA: 48] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Biological effects have been observed from weak, low-frequency magnetic fields. It has been suggested that the observed effects are due to the induced currents and electric fields. The behavior of cells exposed to an electric field is investigated in this paper. The induced transmembrane potential (TMP) is examined in geometrically complex models of various cell configurations. The TMP is evaluated using the finite element method (FEM), a numerical technique that is well suited to complicated geometries. Because displacement currents can be neglected at very low frequencies, a FEM solver that considers only material conductivity is used. Therefore, our results apply only well below the relaxation frequency. Chains and clusters of gap-connected cells of various sizes are modeled. The conductivity and size of the gap junctions in the cell configurations are also varied. The results for small configurations are compared to models of ellipsoidal cells with shapes similar to those of the configurations. FEM estimates of TMP's in long, cylindrical cell chains are compared to the predictions of the leaky cable model. The FEM approach confirms that gap-junction-connected cells can be treated as a single similarly shaped cell. Gaps influence the potential in the interior of cell configurations, and these effects increase with gap size and conductivity. For configurations to which approximations such as the leaky cable model do not apply, the FEM approach can be used to estimate the TMP, if the model is adapted to fit within computational memory limits.
Collapse
Affiliation(s)
- E C Fear
- Department of Electrical and Computer Engineering, University of Victoria, B.C., Canada.
| | | |
Collapse
|
25
|
Sontag W, Dertinger H. Response of cytosolic calcium, cyclic AMP, and cyclic GMP in Dimethylsulfoxide-differentiated HL-60 cells to modulated low frequency electric currents. Bioelectromagnetics 1998. [DOI: 10.1002/(sici)1521-186x(1998)19:8<452::aid-bem2>3.0.co;2-a] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
|
26
|
Sontag W. Two experimental systems for exposure of cells to extremely low frequency electric fields suitable for in situ measurements of fluorescence signals. ACTA ACUST UNITED AC 1997. [DOI: 10.1016/s0302-4598(97)00060-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
27
|
Action of 50 Hz magnetic fields on cAMP content in SV40-3T3 cells: dependence on flux density and extracellular calcium. ACTA ACUST UNITED AC 1997. [DOI: 10.1016/s0302-4598(97)00005-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
28
|
Schimmelpfeng J, Stein JC, Dertinger H. Action of 50 Hz magnetic fields on cyclic AMP and intercellular communication in monolayers and spheroids of mammalian cells. Bioelectromagnetics 1995; 16:381-6. [PMID: 8789069 DOI: 10.1002/bem.2250160606] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
To investigate the influence of physiological parameters such as cell density and three-dimensional cell contact on the biological action of a 2 mT/50 Hz magnetic field, mouse fibroblasts were exposed as monolayers and as multicellular spheroids. Changes in cyclic AMP content of cells and alterations in gap junction-mediated intercellular communication were measured immediately after 5 min of exposure to the field. In monolayers of intermediate cell density (1 x 10(5) cells/cm2), the field treatment caused an increase in cAMP to 121% of the control level, whereas, at 3 x 10(5) cells/cm2 (near confluence), a decrease to 88% of the unexposed cells was observed. Furthermore, field exposure stimulated gap-junction communication to 160% of the control level as determined by Lucifer yellow dye exchange. In spheroids, alterations in the radial profile of cellular cAMP were observed that were due both to field-induced local cAMP changes and to increased gap-junction permeability for this second messenger, the latter causing radial cAMP gradients to be flattened. The results indicate a strong dependence of field action on physiological parameters of the system exposed.
Collapse
Affiliation(s)
- J Schimmelpfeng
- Research Center Karlsruhe, Institute of Toxicology, Karlsruhe, Federal Republic of Germany
| | | | | |
Collapse
|