Pulsed Electrical Stimulation Affects Osteoblast Adhesion and Calcium Ion Signaling

Abstract

An extensive research field in regenerative medicine is electrical stimulation (ES) and its impact on tissue and cells. The mechanism of action of ES, particularly the role of electrical parameters like intensity, frequency, and duration of the electric field, is not yet fully understood. Human MG-63 osteoblasts were electrically stimulated for 10 min with a commercially available multi-channel system (IonOptix). We generated alternating current (AC) electrical fields with a voltage of 1 or 5 V and frequencies of 7.9 or 20 Hz, respectively. To exclude liquid-mediated effects, we characterized the AC-stimulated culture medium. AC stimulation did not change the medium’s pH, temperature, and oxygen content. The H2O2 level was comparable with the unstimulated samples except at 5 V_7.9 Hz, where a significant increase in H2O2 was found within the first 30 min. Pulsed electrical stimulation was beneficial for the process of attachment and initial adhesion of suspended osteoblasts. At the same time, the intracellular Ca2+ level was enhanced and highest for 20 Hz stimulated cells with 1 and 5 V, respectively. In addition, increased Ca2+ mobilization after an additional trigger (ATP) was detected at these parameters. New knowledge was provided on why electrical stimulation contributes to cell activation in bone tissue regeneration.

Synchronous Generation of Electrical and Cellular Energies via Body-Mediated Energy Transfer: Inevitable Electric Field Concentration

“…However, compared to the nonsinusoidal loss, there was a highly significant fatigue reduction effect. This shows a similar result to previous reports in that electric stimulation for Ca ions is more affected by the frequency than the magnitude of the electric field. , …”

“…This shows a similar result to previous reports in that electric stimulation for Ca ions is more affected by the frequency than the magnitude of the electric field. 44,45 In this work, we investigated the inevitable and local electric field formed through body-mediated energy harvesting and the positive physiological effects of this electric field concentration. We analyzed the effects of various variables on energy strength in a wearable application and noted that the energy strength can be controlled by using different methods for grounding the counter electrode.…”

Development of a Cell Culture Chamber for Investigating the Therapeutic Effects of Electrical Stimulation on Neural Growth

“…Electrical signals can be categorized as direct current (DC) or alternating current (AC). In vitro studies utilize both DC [9,11] and AC [17,18] signals, but many implantable electronic devices such as cochlear implants use AC signals as these are considered biologically safe [19]. Signals can vary in current, voltage, frequency, waveforms and duty cycles [20].…”

Short-Time Alternating Current Electrical Stimulation and Cell Membrane-Related Components

“…If MG-63 osteoblasts in suspension were electrically stimulated (ES) with an alternating current (AC) for only 10 min, initial adhesion was increased, and cells were more active. The boost in adhesion was impressively seen in a higher basal Ca 2+ level in the cytoplasm, and the prompt cell reaction was due to an additional adenosine triphosphate (ATP) stimulus with a prolonged steady state [12]. In addition, the production of reactive oxygen species (ROS) was also increased 4 h after AC using the IonOptix multi-channel system [12,13].…”