Electrical stimulation of transforming growth factor-beta 1 secretion by human dermal fibroblasts and the U937 human monocytic cell line

Electrical Stimulation for Immunomodulation

The immune system plays a key role in the development and progression of numerous diseases such as chronic wounds, autoimmune diseases, and various forms of cancer. Hence, controlling the behavior of immune cells has emerged as a promising approach for treating these diseases. Current modalities for immunomodulation focus on chemical based approaches, which while effective have the limitations of nonspecific systemic side effects or requiring invasive delivery approaches to reduce the systemic side effects. Recent advances have unraveled the significance of electrical stimulation as an attractive noninvasive approach to modulate immune cell phenotype and activity. This review provides insights on electrical stimulation strategies employed for regulating the behavior of macrophages, T and B cells, and neutrophils. For obtaining a better understanding, two major types of electrical stimulation sources, conventional and self-powered sources, that have been used for immunomodulation are extensively discussed. Next, the strategies of electrical stimulation that may be applied to cells in vitro and in vivo are discussed, with a focus on conventional and stimuli-responsive self-powered sources. A description of how these strategies influence the polarization, phagocytosis, migration, and differentiation of immune cells is also provided. Finally, recent developments in the use of highly localized and efficient platforms for electrical stimulation based immunomodulation are also highlighted.

Effectiveness of Microcurrent Therapy for Treating Pressure Ulcers in Older People: A Double-Blind, Controlled, Randomized Clinical Trial

The aim of this study was to assess the effectiveness of microcurrent therapy for healing pressure ulcers in aged people. A multicentric, randomized clinical trial was designed with a sham stimulation control. The experimental group received an intervention following a standardized protocol for curing ulcers combined with 10 h of microcurrent therapy daily for 25 days. The sham group received the same curing protocol plus a sham microcurrent stimulation. The studied healing-related variables were the Pressure Ulcer Scale for Healing (PUSH) and the surface, depth, grade, and number of ulcers that healed completely. Three evaluations were conducted: pre-intervention (T1), 14 days following the start of the intervention (T2), and 1 day after the intervention was completed (T3). In total, 30 participants met the inclusion criteria (n = 15 in each group). The improvement in the PUSH at T2 and T3 was 16.8% (CI95% 0.5-33.1) and 25.3% (CI95% 7.6-43.0) greater in the experimental group versus the sham control, respectively. The reduction in the wound area at T2 and T3 was 20.1% (CI95% 5.2-35.0) and 28.6% (CI95% 11.9-45.3) greater in the experimental group versus the control, respectively. Microcurrent therapy improves the healing of pressure ulcers in older adults, both quantitatively and qualitatively.

Electrical microcurrent stimulation therapy for wound healing: A meta-analysis of randomized clinical trials

BACKGROUND

Electrical microcurrent therapy (EMT) consists of the application of low intensity (μA) currents that are similar to endogenous electric fields generated during wound healing.

AIMS

To examine the effectiveness and safety of EMT for improving wound healing and pain in people with acute or chronic wounds.

METHOD

Randomized clinical trials (RCTs) assessing the effectiveness of EMT in wound healing published up to August 1st, 2020 were included. The main outcomes were wound surface area, healing time, and number of wounds healed. Secondary outcomes were pain perception and adverse events. A quantitative analysis was conducted using the inverse variance and Mantel-Haenszel methods.

RESULTS

Eight RCTs were included in the qualitative summary and seven in the quantitative analysis (n = 337 participants). EMT plus standard wound care (SWC) produced a greater decrease in wound surface [mean difference (MD) = -8.3 cm²; CI 95%: -10.5 to -6.0] and healing time (MD = -7.0 days; CI 95%: -11.9 to -2.1) that SWC alone, showing moderate and low certainty in the evidence, respectively. However, no differences were observed in the number of healed wounds [risk ratio = 2.0; CI 95%: 0.5 to 9.1], with very low quality of evidence. EMT decreased perceived pain (MD = -1.4; CI 95%: -2.7 to -0.2), but no differences in adverse effects were noted between groups (risk difference = 0.05; CI 95%: -0.06 to 0.17).

CONCLUSIONS

EMT is an effective, safe treatment for improving wound area, healing time, and pain. Further clinical trials that include detailed intervention parameters and protocols should be designed to lower the risk of bias.

Microcurrent Stimulation Triggers MAPK Signaling and TGF-β1 Release in Fibroblast and Osteoblast-Like Cell Lines

Wound healing constitutes an essential process for all organisms and involves a sequence of three phases. The disruption or elongation of any of these phases can lead to a chronic or non-healing wound. Electrical stimulation accelerates wound healing by mimicking the current that is generated in the skin after any injury. Here, we sought to identify the molecular mechanisms involved in the healing process following in vitro microcurrent stimulation-a type of electrotherapy. Our results concluded that microcurrents promote cell proliferation and migration in an ERK 1/2- or p38-dependent way. Furthermore, microcurrents induce the secretion of transforming growth factor-beta-1 (TGF-β1) in fibroblasts and osteoblast-like cells. Interestingly, transcriptomic analysis uncovered that microcurrents enhance the transcriptional activation of genes implicated in Hedgehog, TGF-β1 and MAPK signaling pathways. Overall, our results demonstrate that microcurrents may enhance wound closure through a combination of signal transductions, via MAPK's phosphorylation, and the transcriptional activation of specific genes involved in the healing process. These mechanisms should be further examined in vivo, in order to verify the beneficial effects of microcurrents in wound or fracture healing.

Efficacy of electrical neuromuscular stimulation in the treatment of chronic periodontitis

Purpose

The purpose of the present randomized controlled clinical study was to evaluate the short-term outcomes of microcurrent electrical neuromuscular stimulation (MENS) as an adjunct method to nonsurgical periodontal therapy.

Methods

Twenty patients with moderate to severe chronic periodontitis were recruited into the study and randomly treated with either nonsurgical periodontal therapy followed by 5 MENS treatments with a microcurrent device or by nonsurgical periodontal therapy alone. Periodontal parameters were measured at baseline and 6 weeks following therapy, and included the plaque index, bleeding on probing, probing depth, and clinical attachment level (CAL).

Results

All measured values were reduced at the time of re-evaluation. The amount of inflammation was significantly reduced in both the test (P=0.002) and control group (P=0.015). The test group demonstrated a significant CAL gain at 6 weeks following therapy, including non-molar (P=0.009) and molar teeth (P=0.028). In comparison with the control group, the test group showed statistically significant differences in the CAL on both molar (P=0.027) and non-molar teeth (P=0.031).

Conclusions

In conclusion, the short-term results of the study indicate that MENS could be a suitable adjunctive method in the treatment of chronic periodontitis.

Millicurrent stimulation of human articular chondrocytes cultivated in a collagen type-I gel and of human osteochondral explants

BACKGROUND

Here we investigate the effect of millicurrent treatment on human chondrocytes cultivated in a collagen gel matrix and on human osteochondral explants.

METHODS

Human chondrocytes from osteoarthritic knee joints were enzymatically released and transferred into a collagen type-I gel. Osteochondral explants and cell-seeded gel samples were cultivated in-vitro for three weeks. Samples of the verum groups were stimulated every two days by millicurrent treatment (3 mA, sinusoidal signal of 312 Hz amplitude modulated by two super-imposed signals of 0.28 Hz), while control samples remained unaffected. After recovery, collagen type-I, type-II, aggrecan, interleukin-1beta, IL-6, TNFalpha and MMP13 were examined by immunohistochemistry and by real time PCR.

RESULTS

With regard to the immunostainings 3 D gel samples and osteochondral explants did not show any differences between treatment and control group. The expression of all investigated genes of the 3 D gel samples was elevated following millicurrent treatment. While osteochondral explant gene expression of col-I, col-II and Il-1beta was nearly unaffected, aggrecan gene expression was elevated. Following millicurrent treatment, IL-6, TNFalpha, and MMP13 gene expression decreased. In general, the standard deviations of the gene expression data were high, resulting in rarely significant results.

CONCLUSIONS

We conclude that millicurrent stimulation of human osteoarthritic chondrocytes cultivated in a 3 D collagen gel and of osteochondral explants directly influences cell metabolism.

Ultra-low microcurrent in the management of diabetes mellitus, hypertension and chronic wounds: report of twelve cases and discussion of mechanism of action

Oxidative stress plays a major role in the pathogenesis of both types of diabetes mellitus and cardiovascular diseases including hypertension. The low levels of antioxidants accompanied by raised levels of markers of free radical damage play a major role in delaying wound healing. Ultra-low microcurrent presumably has an antioxidant effect, and it was shown to accelerate wound healing. The purpose of the study is to investigate the efficacy of ultra-low microcurrent delivered by the Electro Pressure Regeneration Therapy (EPRT) device (EPRT Technologies-USA, Simi Valley, CA) in the management of diabetes, hypertension and chronic wounds. The EPRT device is an electrical device that sends a pulsating stream of electrons in a relatively low concentration throughout the body. The device is noninvasive and delivers electrical currents that mimic the endogenous electric energy of the human body. It is a rechargeable battery-operated device that delivers a direct current (maximum of 3 milliAmperes) of one polarity for 11.5 minutes, which then switched to the opposite polarity for another 11.5 minutes. The resulting cycle time is approximately 23min or 0.000732 Hz and delivers a square wave bipolar current with a voltage ranging from 5V up to a maximum of 40 V. The device produces a current range of 3 mA down to 100 nA. Twelve patients with long standing diabetes, hypertension and unhealed wounds were treated with EPRT. The patients were treated approximately for 3.5 h/day/5 days a week. Assessment of ulcer was based on scale used by National Pressure Ulcer Advisory Panel Consensus Development Conference. Patients were followed-up with daily measurement of blood pressure and blood glucose level, and their requirement for medications was recorded. Treatment continued from 2-4 months according to their response. Results showed that diabetes mellitus and hypertension were well controlled after using this device, and their wounds were markedly healed (30-100%). The patients either reduced their medication or completely stopped after the course of treatment. No side effects were reported. The mechanism of action was discussed.

Ultra-low microcurrent therapy: a novel approach for treatment of chronic resistant wounds

This study was undertaken to investigate the efficacy of ultra-low microcurrent delivered by the Electro Pressure Regeneration Therapy (EPRT) device for the management of chronic wounds. In this study, 23 patients with chronic skin ulcers and 2 with abdominal dehiscence that was present for an average of 16.5 mo, who were not responsive to standard conservative treatment in a hospital setting, were treated with the EPRT device. Wounds were treated with direct current (maximum of 3 mA) of 1 polarity for 11.5 min and then with a current of the opposite polarity for another 11.5 min. Treatment was applied through ultra-low microcurrents (in the mA to nA range) conducted through special wraps applied above and below the wound. The results revealed that 34.8% of cases achieved complete wound healing after an average of 45.6 h of treatment, and 39.1% achieved >or=50% healing after an average of 39.7 h of treatment. Several patients achieved significant results after 1 to 2 treatments. The EPRT device not only accelerated healing but also appeared to negate the effect of a person's age on wound healing.

Influence of monocyte-like cells on the fibrinolytic activity of peritoneal mesothelial cells and the effect of sodium hyaluronate

OBJECTIVE

To determine whether the presence of cells of the monocyte-macrophage system affects the fibrinolytic response of peritoneal mesothelial cells to lipopolysaccharide (LPS) in the presence and absence of sodium hyaluronate.

DESIGN

Controlled laboratory experiment.

SETTING

Cell cultures in an academic laboratory research environment.

PATIENT(S)

Human peritoneal mesothelial cells were harvested from patients undergoing a laparotomy for noninfectious reasons and were cultured in vitro. Co-cultures were formed by adding U-937 human monocyte-like cells to a monolayer of mesothelial cells.

INTERVENTION(S)

After 24 hours, cultures were treated with 10 ng/mL of LPS, and sodium hyaluronate was added in a final concentration of 0.2%. Controls received medium without sodium hyaluronate.

MAIN OUTCOME MEASURE(S)

After 24 hours' incubation, tissue plasminogen activator (tPA), urokinase plasminogen activator (uPA), and plasminogen activator inhibitor-1 (PAI-1) levels were determined in medium and cell lysates by using ELISA techniques.

RESULT(S)

In medium of co-cultures, tPA and PAI-1 concentrations were statistically significantly increased compared with the case of monocultures, whereas uPA concentration was statistically significantly decreased. In cell lysates of co-cultures, PAI-1 concentration was statistically significantly increased compared with the case of monocultures, whereas tPA and uPA were unaffected. Treatment with sodium hyaluronate statistically significantly decreased PAI-1 and uPA concentrations in medium of monocultures but decreased uPA concentration only in medium of co-cultures, compared with the case of controls.

CONCLUSION(S)

Cells of the monocyte-macrophage system modulate the fibrinolytic capacity of LPS treated human peritoneal mesothelial cells and interfere in the hyaluronan-associated changes in mesothelial fibrinolytic capacity.

Metabolic regulation of coronary vascular tone: role of endothelin-1

Coronary tone is determined by a balance between endogenously produced endothelin and metabolic dilators. We hypothesized that coronary vasodilation during augmented metabolism is the net result of decreased endothelin production and increased production of vasodilators. Isolated rat myocytes were stimulated at 0, 200, and 400 beats/min to modify metabolism. Supernatant from these preparations was added to isolated coronary arterioles with and without blocking vasoactive pathways (adenosine, bradykinin, and endothelin). Chronically instrumented swine were studied while resting and running on a treadmill before and after endothelin type A (ET(A)) receptor blockade. The vasodilatory properties of the supernatant increased with increased stimulation frequencies. Combined blockade of adenosine and bradykinin receptors abolished vasodilation in response to supernatant of stimulated myocytes. ET(A) blockade increased vasodilation to supernatant of unstimulated myocytes but did not affect dilation to supernatant of myocytes stimulated at 400 beats/min. In vivo, ET(A) blockade resulted in coronary vasodilation at rest, which waned during exercise. Thus endothelin has a tonic constrictor influence through the ET(A) receptor at low myocardial metabolic demand but its influence decreased during increased metabolism.