Electrochemical and electrical aspects of low-frequency electromagnetic current induction in biological systems

Pilla, Arthur A.; Sechaud, P.; McLeod, Bruce R.

doi:10.1007/bf01872941

Cited by 37 publications

(4 citation statements)

References 56 publications

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“…The search coil consisted of 12 turns of 30 AWG with an internal diameter of 12.8 mm. The actual induced electric potential in the medium was also measured by using a Pilla-type probe [Pilla et al, 1983] connected directly to the oscilloscope. The measurements were made with the probe submerged in the fluid and the tips aligned with the electric field lines.…”

Section: Stimulating Systemmentioning

confidence: 99%

The effects of pulsed electromagnetic fields on the cellular activity of SaOS‐2 cells

Martino¹,

Belchenko²,

Ferguson³

et al. 2007

Bioelectromagnetics

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Although pulsed electromagnetic fields (PEMFs) have been used for treatments of nonunion bone fracture healing for more than three decades, the underlying cellular mechanism of bone formation promoted by PEMFs is still unclear. It has been observed that a series of parameters such as pulse shape and frequency should be carefully controlled to achieve effective treatments. In this article, the effects of PEMFs with repetitive pulse burst waveform on the cellular activity of SaOS-2 osteoblast-like cells were investigated. In particular, cell proliferation and mineralization due to the imposed PEMFs were assessed through direct cell counts, the MTT assay, tissue nonspecific alkaline phosphatase (ALP) and Alizarin Red S (ARS) staining. PEMF stimulation with repetitive pulse burst waveform did not affect metabolic activity and cell number. However, the ALP activity of SaOS-2 cells and mineral nodule formation increased significantly after PEMF stimulation. These observations suggest that repetitive pulse burst PEMF does not affect cellular metabolism; however, it may play a role in the enhancement of SaOS-2 cell mineralization. We are currently investigating cellular responses under different PEMF waveforms and Western blots for protein expression of bone mineralization specific proteins.

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Section: Stimulating Systemmentioning

confidence: 99%

The effects of pulsed electromagnetic fields on the cellular activity of SaOS‐2 cells

Martino¹,

Belchenko²,

Ferguson³

et al. 2007

Bioelectromagnetics

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“…In order to evaluate the second term on the right-hand side in Eq. [1], it is physically meaningful to provide for finite adsorption kinetics (2,3,23,29) via…”

Section: Resultsmentioning

confidence: 99%

“…[2] and [3]). Experiments to be reported elsewhere (29) show that this time constant, TA --RACA, depends strongly on extracellular K + concentration. The successful use of periodic current pulses designed to couple to TA to influence Na-K ATPase activity (30) in HRBC, provides a strong correlation between cell surface electrochemistry, and the electromagnetic modulation of cell and tissue function (3).…”

Section: /Z(s) = Cds + Qrars/(1 -B Rs/v)mentioning

confidence: 94%

A Transient Impedance Approach to Nonfaradaic Electrochemical Kinetics at Living Cell Membranes

Schmukler

Pilla

1982

J. Electrochem. Soc.

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This study describes a new high resolution impedance technique by which electrochemical kinetic parameters of physiological relevance for living cell surfaces can be obtained. Isolated cells are forced, via hydrostatic pressure, into the pores of an insulation filter membrane, minimizing extracellular current pathways. Cell surface relaxations are thereby observable in the transient response which is interpreted via electrochemical models involving dielectric charging and specific adsorption. Application to the human red blood cell has isolated a transient current pathway which appears to be related to the kinetics of membrane bound enzyme activity.This study describes a method of greatly increased sensitivity for the evaluation of isolated cell impedances. The results obtained provide data relevant to the choice of signal parameters for periodic electrical waveforms capable of modulating cell and tissue function. The original electrochemical information transfer concept (1-3) considered the kingtics of specific potential dependent ion and dipole interactions at cell surfaces and junctions in relation to the known involvement of ions in cell regulation (4,5). This led to the hypothesis that appropriate kinetic coupling to these processes can influence functional activity. Such an approach with electromagnetically induced current having a waveform configured by one of us (AAP) was first reported to alter the tempo of fracture repair in vivo (6, 7). Many successful applications to a variety of in vitro and in vivo systems have since been reported (8-11), including a major clinical application for the surgically noninvasive repair of some recalcitrant bone fractures (12, 13). Here a new technique is described which allows high resolution detection of electrochemical kinetic parameters of physiological relevance for isolated cells. A quantitative application to human erythrocytes (HRBC) is given. ExperimentalThe objective is to obtain electrical relaxation measurements over the anticipated wide frequency (time) range of the kinetics of electrochemical surface (membrane) processes for isolated (nonepithelial) cells in physiologically meaningful conditions. To avoid membrane puncture with microelectrodes, previous techniques have utilized cell suspensions (14-18). The sensitivity of this approach is severely compromised, particularly in the frequency range of interest, due to the relatively high conductivity of the isotonic salt suspending solution which shunts a majority of current around the cells. The methodology of the present study utilized a Nuclepore TM filter composed of polycarbonate insulating material, containing well-defined and uniform cylindrical pores. Freshly isolated human red blood cells are washed three times in isotonic Ringer solution (0.15M NaC1, 4 mM KC1, 1 mM CaC12, phosphate buffered to pH 7.4). The washed cells are placed in a vertical conductivity cell containing a Nuclepore TM filter with 2.8 • 10~ (___10%) pores/cm 2 of 2.05 __ 0.05 ~,m diam, and 13.0 • 0.5 #m length having a maximum deviat...

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“…Thus, the mean peak electric field, evaluated via E(t) ¼ ÀdB/dt*r/2 (where r is the target radius and dB/dt is proportional to dI coil /dt as shown in Fig. 2) [Pilla et al, 1983], was approximately 1 mV/cm in the successful in vitro study, whereas that for the maximum amplitude in this study (3 mT) was approximately 0.1 mV/cm, given the geometry differences between the culture dish and the anatomical location of the sciatic nerve injury in the rat. This suggests insufficient amplitude (dose) at the sciatic nerve injury may have contributed to the lack of EMF effect observed in this study.…”

Section: Discussionmentioning

confidence: 99%

Electromagnetic Field Treatment of Nerve Crush Injury in a Rat Model: Effect of Signal Configuration on Functional Recovery

Walker

Smith

Pilla

et al. 2007

Bioelectromagnetics

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Electromagnetic fields (EMFs) have been demonstrated to enhance mammalian peripheral nerve regeneration in vitro and in vivo. Using an EMF signal shown to enhance neurite outgrowth in vitro, we tested this field in vivo using three different amplitudes. The rat sciatic nerve was crushed. Whole body exposure was performed for 4 h/day for 5 days in a 96-turn solenoid coil controlled by a signal generator and power amplifier. The induced electric field at the target tissue consisted of a bipolar rectangular pulse, having 1 and 0.3 ms durations in each polarity, respectively. Pulse repetition rate was 2 per second. By varying the current, the coils produced fields consisting of sham (no current) and peak magnetic fields of 0.03 mT, 0.3 mT, and 3 mT, corresponding to peak induced electric fields of 1, 10, and 100 microV/cm, respectively, at the tissue target. Walking function was assessed over 43 days using video recording and measurement of the 1-5 toe-spread, using an imaging program. Comparing injured to uninjured hind limbs, mean responses were evaluated using a linear mixed statistical model. There was no difference found in recovery of the toe-spread function between any EMF treatments compared to sham.

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Electrochemical and electrical aspects of low-frequency electromagnetic current induction in biological systems

Cited by 37 publications

References 56 publications

The effects of pulsed electromagnetic fields on the cellular activity of SaOS‐2 cells

The effects of pulsed electromagnetic fields on the cellular activity of SaOS‐2 cells

A Transient Impedance Approach to Nonfaradaic Electrochemical Kinetics at Living Cell Membranes

Electromagnetic Field Treatment of Nerve Crush Injury in a Rat Model: Effect of Signal Configuration on Functional Recovery

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