Background: Bioelectrical properties are known to impact stem cell fate, state, and function. However, assays that measure bioelectrical properties are generally limited to the plasma membrane potential. In this study, we propose an assay to simultaneously assess cell plasma membrane and mitochondrial membrane potentials. Materials and Methods: Mesenchymal stem cell (MSC) plasma and mitochondrial membrane potentials were measured using flow cytometry and a combination of tetramethylrhodamine, methyl ester (TMRM), and bis-(1,3-dibutylbarbituric acid)trimethine oxonol (DiBAC) dyes. We investigated the shifts in the bioelectrical phenotype of MSCs due to extended culture in vitro, activation with interferon-gamma (IFN-γ), and aggregate conditions. Results: MSCs subjected to extended culture in vitro acquired plasma and mitochondrial membrane potentials consistent with a hyperpolarized bioelectrical phenotype. Activation with IFN-γ shifted MSCs toward a state associated with increased levels of both DiBAC and TMRM. MSCs in aggregate conditions were associated with a decrease in TMRM levels, indicating mitochondrial depolarization. Conclusions: Our proposed assay described distinct MSC bioelectrical transitions due to extended in vitro culture, exposure to an inflammatory cytokine, and culture under aggregate conditions. Overall, our assay enables a more complete characterization of MSC bioelectrical properties within a single experiment, and its relative simplicity enables researchers to apply it in variety of settings.

BioelectricityVol. 2, No. 2 MeetingsFree AccessBioelectricity Meetings Around the WorldPublished Online:17 Jun 2020https://doi.org/10.1089/bioe.2020.29021.bwmAboutSectionsPDF/EPUB ToolsAdd to favoritesDownload CitationsTrack CitationsPermissions Back To Publication ShareShare onFacebookTwitterLinked InRedditEmail Covid-19 has played havoc with scientific meetings around the world, including those in the general area of bioelectricity. Here is a list updated from the last issue of Bioelectricity. Further updates will be given in the next issue.1. 6th International Winterschool on Bioelectronics (BioEl 2020) – Cancelled14–21 March, 2020; Kirchberg in Tirol, Austriahttps://www.jku.at/en/institute-of-physical-chemistry-and-linz-institute-of-organic-solar-cells/conferences/2. Bio-Electrical Engineering (BEE) Innovation Hub - 3rd Workshop – New date, 25–26 January, 202127–28 April, 2020; Radcliffe Conference Centre, University of Warwick, Coventry, CV4 7SH, UKhttps://warwick.ac.uk/fac/sci/lifesci/research/beehive/bee_2020/3. Ion Channels & Cancer Meeting 2020 and Calcium Signalling in Cancer - Postponed to 2021, dates TBD11–14 May, 2020; Couvent des Minimes, Lille, Francehttps://iccm2020.univ-lille.fr/4. 1st Bioelectronics Workshop - Cancelled13–14 May, 2020; University of Nottingham, Nottingham, UKhttps://www.eventbrite.co.uk/e/the-uks-1st-bioelectronics-for-healthcare-workshop-tickets-952414146355. Gordon Research Conference on Ion Channels (Molecular Mechanisms of Electrical Signaling in Health and Disease) - Rescheduled for 2022, dates TBD12 – 17 July, 2020; Mount Holyoke College, South Hadley, MA, USAhttps://www.grc.org/ion-channels-conference/2020/6. The 74th Annual Meeting of the Society of General Physiologists (SGP) Topic: Ion Channels and Transporters in Immunity, Inflammation and Antitumor ImmunitySeptember 9 – 13, 2020 - Postponed to September 8–12, 2021Marine Biology Labs, Woods Hole, MA, USAOrganizers: Stefan Feske (New York University), Bimal Desai (University of Virginia)https://www.sgp2020.com/7. The European Conference on Clinical Studies with Medical Devices and IVDs (CSMD2020)16–17 November 2020 ; Vienna, Austriahttps://csmd2020.com/congress-program/FiguresReferencesRelatedDetails Volume 2Issue 2Jun 2020 InformationCopyright 2020, Mary Ann Liebert, Inc., publishersTo cite this article:Bioelectricity.Jun 2020.203-203.http://doi.org/10.1089/bioe.2020.29021.bwmPublished in Volume: 2 Issue 2: June 17, 2020PDF download

Biological systems overwhelmingly comprise charged entities generating electrical activity that can have significant impact on biological structure and function. This intrinsic bio-electrical activity can also be harnessed for overcoming the tissue matrix and cell membrane barriers, which have been outstanding challenges for targeted drug delivery, by using rationally designed cationic carriers. The weak and reversible long-range electrostatic interactions with fixed negatively charged groups facilitate electro-diffusive transport of cationic therapeutics through full-tissue thickness to effectively reach intra-tissue, cellular, and intracellular target sites. This article presents a perspective on the promise of using rationally designed cationic biomaterials in targeted drug delivery, the underlying charge-based mechanisms, and bio-transport phenomena while addressing outstanding concerns around toxicity and methods to mitigate them. We also discuss electrically charged drugs that are currently being evaluated in clinical trials and identify areas of further development that have the potential to usher in new treatments.

Background: Neural precursor cells (NPCs) hold great promise for neural repair. Endogenous NPCs, found in the subventricular zone of the adult brain, proliferate and migrate toward lesion sites; however, it is not sufficient for neural repair. NPCs are electrosensitive cells that undergo directed migration in an electric field (EF). Here, we examined the EF-induced migration of a clinically relevant human NPC population. Materials & Methods: We examined the effects of different substrates and microenvironments on human NPC galvanotaxis. Results: Human NPCs increased their migration speed in the presence of an EF, and the direction of migration (anodal vs. cathodal) varied between substrates. The secretome and extracellular pH were not significant factors in EF-induced migration; however, our results are consistent with substrate stiffness playing a role in the direction of cell migration. Conclusion: These findings provide insight into the importance of the microenvironment on modulating human NPC migration and highlight substrate-dependent considerations for neurorepair.

Hypothesis: In our clinical study, the stages of pregnancy were independent variables, and the measured change of sensitivity in selected skin areas was the dependent variable. The research hypothesis that the threshold electric skin sensitivity (TESS) fluctuates was based on our previously published research, where the null hypothesis was rejected in similar conditions.Methods: TESS was measured repeatedly in short intervals on the abdomen and right forearm of pregnant and not pregnant women.Results: A statistically very significant change of TESS fluctuation was found between not pregnant and pregnant women in different stages of pregnancy, labor, and postpartum. In the midline above the navel, the TESS fluctuates with similar frequency like intestinal peristalsis and that may reflect on the functional state of the bowels. In both lateral areas of the lower abdomen in not pregnant women and in early pregnancy, we found only minimal TESS fluctuations. They gradually increased until the beginning of labor and then decreased postpartum. In midline above the pubic symphysis, moderate TESS fluctuation in not pregnant women gradually increased during pregnancy, until the beginning of labor and decreased postpartum. TESS fluctuation during labor was not synchronous with recorded uterine contractions. Only minimal TESS fluctuation on the right forearm never changed significantly.Conclusion: TESS fluctuation in midline abdomen may be related to bowel peristaltic motility. In the lateral abdomen and above symphysis, it may be related to uterus activity. TESS measurement in referral pain skin area could be used for functional monitoring of internal organ in the corresponding viscerotome. The measurement of TESS in skin areas and recording fluctuations graphically as an electrosensitogram, could have diagnostic value. As a new noninvasive diagnostic method, electrosensitography could help us better understand the gastrointestinal organ function.

Selective serotonin reuptake inhibitor (SSRI) drugs, targeting serotonin transport, are widely used. A puzzling and biomedically important phenomenon concerns the persistent sexual dysfunction following SSRI use seen in some patients. What could be the mechanism of a persistent physiological state brought on by a transient exposure to serotonin transport blockers? In this study, we briefly review the clinical facts concerning this side effect of serotonin reuptake inhibitors and suggest a possible mechanism. Bioelectric circuits (among neural or non-neural cells) could persistently maintain alterations of bioelectric cell properties (resting potential), resulting in long-term changes in electrophysiology and signaling. We present new data revealing this phenomenon in planarian flatworms, in which brief SSRI exposures induce long-lasting changes in resting potential profile. We also briefly review recent data linking neurotransmitter signaling to developmental bioelectrics. Further study of tissue bioelectric memory could enable the design of ionoceutical interventions to counteract side effects of SSRIs and similar drugs.

Electrochemotherapy is gaining recognition as an effective local therapy that uses systemically or intratumorally injected bleomycin or cisplatin with electroporation as a delivery system that brings drugs into the cells to exert their cytotoxic effects. Preclinical work is still ongoing, testing new drugs, seeking the best treatment combination with other treatment modalities, and exploring new sets of pulses for effective tissue electroporation. The applications of electrochemotherapy are being fully exploited in veterinary oncology, where electrochemotherapy, because of its simple execution, has a relatively good cost-benefit ratio and is used in the treatment of cutaneous tumors. In human oncology, electrochemotherapy is fully recognized as a local therapy for cutaneous tumors and metastases. Its effectiveness is being explored in combination with immunomodulatory drugs. However, the development of electrochemotherapy is directed into the treatment of deep-seated tumors with a percutaneous approach. Because of the vast number of reports, this review discusses the articles published in the past 5 years.

As the leading cause of death in cancer, there is an urgent need to develop treatments to target the dissemination of primary tumor cells to secondary organs, known as metastasis. Bioelectric signaling has emerged in the last century as an important controller of cell growth, and with the development of current molecular tools we are now beginning to identify its role in driving cell migration and metastasis in a variety of cancer types. This review summarizes the currently available research for bioelectric signaling in solid tumor metastasis. We review the steps of metastasis and discuss how these can be controlled by bioelectric cues at the level of a cell, a population of cells, and the tissue. The role of ion channel, pump, and exchanger activity and ion flux is discussed, along with the importance of the membrane potential and the relationship between ion flux and membrane potential. We also provide an overview of the evidence for control of metastasis by external electric fields (EFs) and draw from examples in embryogenesis and regeneration to discuss the implications for endogenous EFs. By increasing our understanding of the dynamic properties of bioelectric signaling, we can develop new strategies that target metastasis to be translated into the clinic.

Voltage-gated potassium channels are transmembrane proteins that allow flow of potassium across the membrane to regulate ion homeostasis, cell proliferation, migration, cell volume, and specific processes such as muscular contraction. Aberrant function or expression of potassium channels can underlie pathologies ranging from heart arrhythmia to cancer; the expression of potassium channels is altered in many types of cancer and that alteration correlates with malignancy and poor prognosis. Targeting potassium channels therefore constitutes a promising approach for cancer therapy. In this review, we discuss strategies to target a particular family of potassium channels, the voltage-gated potassium channels (KV) where a reasonable structural understanding is available. We also discuss the possible obstacles and advantages of such a strategy.

Background: The fundamental electrical properties of bone have been attributed to the organic collagen and the inorganic mineral component; however, contributions of individual components within bone tissue toward the measured electrical properties are not known. In our study, we investigated the electrical properties of cell-mediated mineral deposition process and compared our results with cell-free mineralization. Materials and Methods: Saos-2 cells encapsulated within gelatin methacrylate (GelMA) hydrogels were chemically stimulated in osteogenic medium for a period of 4 weeks. The morphology, composition, and mechanical properties of the mineralized constructs were characterized using bright-field imaging, scanning electron microscopy (SEM) energy-dispersive X-ray spectroscopy, Fourier-transform infrared spectroscopy (FITR), nuclear magnetic resonance spectroscopy (NMR), micro-CT, immunostaining, and mechanical compression tests. In parallel, a custom-made device was used to measure the electrical impedance of mineralized constructs. All results were compared with cell-free GelMA hydrogels mineralized through the simulated body fluid approach. Results: Results demonstrate a decrease in the electrical impedance of deposited mineral in both cell-mineralized and cell-free mineralized samples. Conclusions: This study establishes a model system to investigate in vivo and in vitro mineralization processes.