The Use of Pulsed Electromagnetic Field to Modulate Inflammation and Improve Tissue Regeneration: A Review

Influences of physical stimulations on the migration and differentiation of Schwann cells involved in peripheral nerve repair

Peripheral nerve injury repair has always been a research concern of scientists. At the tissue level, axonal regeneration has become a research spotlight in peripheral nerve repair. Through transplantation of autologous nerve grafts or other emerging biomaterials functional recovery after facial nerve injury is not ideal in clinical scenarios. Great strides have been made to improve facial nerve repair at the micro-cellular level. Physical stimulation techniques can trigger Schwann cells (SCs) to migrate and differentiate into cells required for peripheral nerve repair. Classified by the sources of physical stimulations, SCs repair peripheral nerves through galvanotaxis, magnetotaxis and durotaxis. This article summarized the activation, directional migration and differentiation of SCs induced by physical stimulations, thus providing new ideas for the research of peripheral nerve repair.

Case Study: The Benefits of the Neubie Direct Current Electrical Stimulation Device for Pain, Spasticity, and Movement in Amyotrophic Lateral Sclerosis

This case study reports the impact of the Neubie direct current electrical stimulation device in helping restore nerve conduction and function in a 65-year-old woman with sporadic ALS. Use of the Neubie began 12 months after her sudden onset of symptoms. By then, she could not move her fingers or toes, had drop foot, had lost considerable weight and muscle mass, and was in pain. After her first Neubie session, she could wiggle her toes and that movement persisted. After two months she had no hip pain and was moving her fingers, toes, hands, and feet. The Master Reset protocol was used to facilitate the calming of the nervous system and required a sequential increase of settings. She then developed tight, painful shoulders from being in a wheelchair and Neubie treatments on her shoulders ultimately allowed her to become pain-free and regain some range of motion to increase her shoulder flexibility. Her voice then became soft due to a weak diaphragm. After two months she could feel the Neubie treatments increase the innervation of her diaphragm. At the time of this data collection and work, she was pain-free, had increased movement and range of motion, and had more energy. She showed improvements in muscle activation and strength in her legs and was able to stand with assistance. The results of this case study support the need to further study the impact of the Neubie in ALS, especially early in the course of the disease.

Investigation of the efficiency of pulsed electromagnetic field treatment and stretching exercise in experimental skeletal muscle injury model

OBJECTIVE

Pulsed electromagnetic fields (PEMF) and stretching exercises are safe and noninvasive methods that could have a therapeutic effect on tissue healing. This study aimed to assess the effectiveness of these methods in treatment of muscle injury (INJ).

METHOD

Rats were divided into 5 groups (Control, INJ, INJ + Exercise, INJ + PEMF, INJ + Exercise + PEMF). At the end of the experiment, genetic, histopathological, and immunohistochemical evaluations were made in the muscle tissue.

RESULTS

Mononuclear cell infiltration, muscle degeneration, atrophy, and necrosis were found to be higher in the INJ group than in all groups (p < 0.001). On the 7th day, fibroblast growth factor (FGF) was found to be higher in the INJ group compared to both the control and the INJ + Exercise group (p < 0.05). On the 14th day, Vascular endothelial growth factor values were found to be higher in the injury group than the other groups except for the PEMF group (p < 0.05), and FGF values were higher in the injury group compared to all groups (p < 0.001). The expressions of transforming growth factor beta 1 (TGF-β1) and endothelial nitric oxide synthase (eNOS) on the 7th and 14th days showed a significant increase in the INJ group compared to the other groups (p < 0.001).

CONCLUSION

In this study, it has been shown that PEMF and stretching exercise is effective in the treatment of muscle injuries as they balance the inflammatory process in the muscle, have a positive effect on muscle development, accelerate healing, prevent fibrosis development by reducing TGF-β1 signaling, and inhibit inflammatory-induced eNOS activity.

Feasibility, acceptance and effects of pulsed magnetic field therapy in patients with post-COVID-19 fatigue syndrome : A randomized controlled pilot study

INTRODUCTION

The aim of this randomized, single-blinded, placebo-controlled pilot study was to explore the feasibility, acceptance and effects of pulsed electromagnetic field therapy (PEMF) in patients with post-COVID-19 fatigue syndrome.

METHODS

A total of 20 patients were included in the study. They were randomly assigned to an intervention group (n = 10, male:female = 4 : 5, age = 45 ± 9 years) and a placebo group (n = 10, m:f = 4:6, age: 39 ± 23 years). A Papimi™ Delta professional electromagnetic field therapy device was used for treatment. Controls received a placebo PEMF. In total 10 PEMF sessions (30 min., 2× per week) were applied. Physical performance, health-related quality of life, fatigue, work ability, sleep, pain, anxiety and depression were assessed at baseline, posttreatment and at follow-up 5 weeks after treatment. Feasibility and acceptance were assessed posttreatment.

RESULTS

The intervention group showed a notable improvement in the 6 minutes walking test. The use of PEMF improved fatigue (measured with the Brief Fatigue Inventory and the Multidimensional Fatigue Inventory). Also, the depression subscale of the Hospital Anxiety and Depression Scale, the Insomnia Severity Index, the Work Ability Index and most subscales of the Short Form (SF) 36 questionnaire showed improvement. From the placebo group three patients dropped out. There were no drop-outs in the intervention group. In the intervention group, PEMF was well-accepted and patients showed very good adherence.

CONCLUSION

The results of this pilot study indicate that PEMF is feasible and well accepted. Furthermore, this study population showed improvements in physical and mental health in the intervention group. This study is a promising contribution to this growing research field and provides the required evidence for future efficacy studies on PEMF for post-COVID-19 patients.

Evaluating PEMF vagus nerve stimulation through neck application: A randomized placebo study with volunteers

This study investigates the effects of pulsed electromagnetic field (PEMF) therapy on vagus nerve stimulation through non-invasive neck applications. Exploring the efficacy of PEMF across different frequencies (6 hz, 16 hz, and 32 hz), this double-blind placebo-controlled trial included 485 volunteers to assess its impact on autonomic nervous system functions, particularly targeting sleep disturbances and anxiety. Results demonstrated significant improvements in sleep quality and reduction in anxiety levels, especially notable at 16 hz. These findings suggest that PEMF therapy, by modulating autonomic activity, offers a beneficial non-pharmacological treatment option for related disorders.

The In Vitro Enhancement of Retinal Cell Viability via m6A and m5C RNA Methylation-Mediated Changes in the Levels of Heme Oxygenase (HO-1) and DNA Damage Repair Molecules Using a 50 Hz Sinusoidal Electromagnetic Field (EMF)

Degenerative retinal diseases can lead to blindness if left untreated. At present, there are no curative therapies for retinal diseases. Therefore, effective treatment strategies for slowing the progression of retinal diseases and thus improving patients' life standards are urgently needed. The present study aimed to assess the effect of sinusoidal electromagnetic field (EMF) (50 Hz, 1.3 mT) treatment for 15 and 30 min on spontaneously arising retinal pigment epithelial cells (ARPE-19) and retinal ganglion cells (RGC-5) and its short-term post-treatment significance. Our study indicated the beneficial impact of EMF treatment on the proliferative and migratory capacity of the tested cells. ARPE-19 and RGC-5 cells exposed to an EMF exhibited elevated levels of HO-1, increased N6-methyladenosine (m6A) and N5-methylcytosine (m5C) status mediated by METTL3 and NSUN2, respectively, and changes in levels of DNA damage repair factors, which may contribute to the regenerative properties of ARPE-19 and RGC-5 cells. Overall, this analysis showed that EMF (sinusoidal, 50 Hz, 1.3 mT) treatment may serve as a potential therapeutic strategy for retinal diseases.

Effects of PEMF and LIPUS Therapy on the Expression of Genes Related to Peripheral Nerve Regeneration in Schwann Cells

Peripheral nerve regeneration remains a major challenge in neuroscience, despite advancements in understanding its mechanisms. Current treatments, including nerve transplantation and drug therapies, face limitations such as invasiveness and incomplete recovery of nerve function. Physical therapies, like pulsed electromagnetic fields (PEMF) and low-intensity ultrasound (LIPUS), are gaining attention for their potential to enhance regeneration. This study analyzes the effects of PEMF and LIPUS on gene expression in human primary Schwann cells, which are crucial for nerve myelination and repair. Key genes involved in neurotrophin signaling (NGF, BDNF), inflammation (IL-1β, IL-6, IL-10, TNF-α, TGF-β), and regeneration (CRYAB, CSPG, Ki67) were assessed. The results of this study reveal that combined PEMF and LIPUS therapies promote Schwann cell proliferation, reduce inflammation, and improve the regenerative environment, offering potential for optimizing these therapies for clinical use in regenerative medicine.

A Double-Blinded Randomized Controlled Trial: Can Pulsed Electromagnetic Field Therapy Be a Novel Method for Treating Chronic Rhinosinusitis?

Background and Objectives: Pulsed electromagnetic field (PEMF) therapy offers a promising approach to treating inflammatory diseases. Its notable anti-inflammatory and antimicrobial effects and enhancement of microcirculation in the nasal mucosa make it a valuable treatment option. Despite its potential, the use of PEMF for chronic rhinosinusitis (CRS) is still in its early stages, with limited exploration of its effectiveness. This study aimed to assess the impact of PEMF on alleviating symptoms such as fatigue, headaches, sinus opacifications, and ostiomeatal complex issues associated with CRS. Materials and Methods: Forty-seven patients of both genders with CRS, aged 19 to 40 years, were involved in this study. The participants were randomly assigned to either a magnetic or a control group. The magnetic group underwent a 10 min PEMF session with a 20-gauss magnetic field strength at 7 Hz thrice a week for a month. The control group received the same PEMF application as an inactive device. Before and after the intervention, researchers assessed fatigue levels with a visual analog fatigue scale (VAFS), headache intensity via a numerical pain-rating scale, and the status of sinus opacifications and ostiomeatal complex obstructions by computerized tomography (CT). Results: The study findings showed a significant reduction in fatigue and headache scores in the magnetic group compared to the control group (p < 0.05). Additionally, there was a notable improvement in sinus opacifications and ostiomeatal complex obstructions among participants who received PEMF therapy. Conclusions: PEMF therapy effectively reduces fatigue, headaches, and sinus opacifications in CRS patients, suggesting its potential for inclusion in CRS management guidelines to improve patient outcomes and quality of life. The results of this study indicate that PEMF represents a noninvasive and cost-effective approach for treating adults with mild-to-moderate CRS.

Short-term Effects of Pulsed Electromagnetic Field Therapy for Achilles Tendinopathy: A Randomized Controlled Trial

Background

Pulsed electromagnetic field (PEMF) therapy is a potential nonoperative treatment for Achilles tendinopathy, but the current published literature on its effects is sparse.

Purpose

To evaluate the therapeutic efficacy of PEMF therapy and eccentric exercise for Achilles tendinopathy.

Study Design

Randomized controlled trial; Level of evidence, 1.

Methods

A total of 65 participants met the inclusion criteria and were randomly assigned to either the active PEMF group (n = 33) or the sham group (n = 32). The PEMF group received biweekly PEMF therapy (10 minutes per session) for 8 weeks, plus eccentric exercise for 12 weeks. The sham group received the same eccentric exercise for 12 weeks minus active PEMF exposure. The primary outcome was the Victorian Institute of Sports Assessment-Achilles (VISA-A) questionnaire. The secondary outcomes were numeric pain rating scale (NPRS) score, tendon neovascularity, and total time spent on sports per week. A physical therapist assessed all outcomes at baseline and then 4, 8, and 12 weeks after the commencement of the PEMF treatment. The level of tendon neovascularity was determined by the Öhberg score (range, 0-3).

Results

VISA-A scores improved significantly from baseline to 12 weeks posttreatment in both the PEMF group (from 57.9 to 71.7) and the sham group (from 55.1 to 66.8) (P < .001 for both), with no significant difference in scores between treatment groups throughout the 12 weeks (P = .527). NPRS scores during sports also improved significantly from baseline to 12 weeks for the PEMF group (from 6.05 to 2.95) and the sham group (from 6.45 to 3.85) (P < .001), with no group differences (P = .346).

Conclusion

PEMF therapy, in addition to eccentric exercise, did not improve outcome scores or tendon neovascularity compared with eccentric exercise alone in participants with Achilles tendinopathy.

Registration

NCT05316961 (ClinicalTrials.gov identifier).

Pulsed Electromagnetic Fields for Cervical Spine Fusion in Patients with Risk Factors for Pseudarthrosis

Background

Certain demographics and/or risk factors contribute to complications following cervical spinal surgery including pseudarthrosis, prolonged pain, and reduced quality of life (QoL). Pulsed electromagnetic field (PEMF) stimulation is a non-invasive therapy that may enhance fusion success in at-risk patients.

Objective

To evaluate the safety and efficacy of post-operative adjunctive PEMF therapy following cervical spinal surgery in subjects at risk for pseudarthrosis.

Methods

This prospective, multicenter study investigated PEMF as an adjunctive therapy to cervical spinal fusion procedures in subjects at risk for pseudarthrosis based on having at least one of the following: prior failed fusion, multi-level fusion, nicotine use, osteoporosis, or diabetes. Radiographic fusion status and patient-reported outcomes (SF-36, EQ5D, NDI, and VAS-arm pain and VAS-neck pain) were assessed.

Results

A total of 160 subjects were assessed for fusion 12-months postoperative, and 144 subjects were successfully fused (90.0%). Fusion success for subjects with 1, 2+, or 3+ risk factors was 91.7%, 89.0%%, and 90.9%, respectively. Significant improvements in NDI, VAS-arm and VAS-neck were observed compared to baseline scores (p < 0.001) along with improvements in SF-36 and EQ5D (p < 0.001).

Conclusions

Adjunctive treatment with PEMF provides a high rate of successful fusion and significant improvements in pain, function, and quality of life despite having risk factors for pseudarthrosis.

Regenerative Medicine in Orthopedic Surgery: Expanding Our Toolbox

Regenerative medicine leverages the body's inherent regenerative capabilities to repair damaged tissues and address organ dysfunction. In orthopedics, this approach includes a variety of treatments collectively known as orthoregeneration, encompassing modalities such as prolotherapy, extracorporeal shockwave therapy, pulsed electromagnetic field therapy, therapeutic ultrasound, and photobiomodulation therapy, and orthobiologics like platelet-rich plasma and cell-based therapies. These minimally invasive techniques are becoming prominent due to their potential for fewer complications in orthopedic surgery. As regenerative medicine continues to advance, surgeons must stay informed about these developments. This paper highlights the current state of regenerative medicine in orthopedics and advocates for further clinical research to validate and expand these treatments to enhance patient outcomes.

Pulsed electromagnetic fields (PEMF) as a valid tool in orthognathic surgery to reduce post-operative pain and swelling: a prospective study

PURPOSE

PEMF (pulsed electromagnetic fields) founds application in several medical fields to accelerate bone wounds healing and to reduce inflammation. The aim of our study was to evaluate the effectiveness of PEMF in reducing postoperative swelling and pain in patients undergoing orthognathic surgery.

METHODS

A prospective observational monocentric study was conducted on a sample of 30 patients undergone to orthognathic surgery in Maxillofacial Surgery Unit of University of Naples Federico II. The patients who followed these inclusion criteria were enrolled in the study: age ≥ 18 years, Class III malocclusion, Surgical procedure of Le Fort I osteotomy + Bilateral Sagittal Split Osteotomy (BSSO), Written informed consent. Patients were divided into two groups: Group SD) postoperative standard treatment with medical therapy and cryotherapy, Group SD + PEMF) postoperative standard therapy + PEMF. Each patient underwent a 3D facial scan, at one (1d) and four (4d) days after surgery to compare the swelling reduction. The pain score was assessed through VAS score and analgesics administration amount.

RESULTS

In SD + PEMF group, the facial volume reduction between 1d and 4d scan was on average 56.2 ml (6.23%), while in SD group, it was 23.6 ml (2.63%). The difference between the two groups was 3.6% (p = 0.0168). VAS pain values were significantly higher in SD group compared to SD + PEMF group in the second day after surgery (P = 0.021) and in the total 4 days (P = 0.008).

CONCLUSIONS

Our data suggest that PEMF is valid tool to promote faster postoperative swelling and pain reduction in patients undergoing orthognathic surgery.

Bone Regeneration Revolution: Pulsed Electromagnetic Field Modulates Macrophage-Derived Exosomes to Attenuate Osteoclastogenesis

Introduction

In the process of bone regeneration, a prominent role is played by macrophages involved in both the initial inflammation and the regeneration/vascularization phases, due to their M2 anti-inflammatory phenotype. Together with osteoclasts, they participate in the degradation of the bone matrix if the inflammatory process does not end. In this complex scenario, recently, much attention has been paid to extracellular communication mediated by nanometer-sized vesicles, with high information content, called exosomes (EVs). Considering these considerations, the purpose of the present work is to demonstrate how the presence of a pulsed electromagnetic field (PEMF) can positively affect communication through EVs.

Methods

To this aim, macrophages and osteoclasts were treated in vitro with PEMF and analyzed through molecular biology analysis and by electron microscopy. Moreover, EVs produced by macrophages were characterized and used to verify their activity onto osteoclasts.

Results

The results confirmed that PEMF not only reduces the inflammatory activity of macrophages and the degradative activity of osteoclasts but that the EVS produced by macrophages, obtained from PEMF treatment, positively affect osteoclasts by reducing their activity.

Discussion

The co-treatment of PEMF with M2 macrophage-derived EVs (M2-EVs) decreased osteoclastogenesis to a greater degree than separate treatments.

The effect of electro-magnetic-energy-regulation therapy on subjective sleep among elite players in Norwegian women's football

The current study investigated if Bio-Electro-Magnetic-Energy-Regulation (BEMER) therapy is affecting subjective sleep among a sample of 21 elite female football players in a Norwegian top series club. Subjective sleep was measured each day over a period of 273 consecutive days by using a smartphone application, PM Reporter Pro, which scheduled push messages to remind the participants to report sleep every morning. The study was conducted as a quasi-experimental design, with a control period before the introduction of BEMER therapy that lasted for 3 months, followed by an intervention period where BEMER therapy was used that lasted for 5 months. The collected data from the players in the control period served as their control compared to the data collected from the players in the intervention period. Analyses of variance (ANOVA) with False Discovery Rate adjusted p-values show that subjective sleep duration and subjective sleep quality are significantly reduced on game nights, both in the control period and in the experiment period. The results also show that subjective sleep duration and subjective sleep quality significantly increase in the experiment period compared to the control period. The findings indicate that BEMER therapy might serve as a tool to improve sleep.

A bioelectronic device for electric field treatment of wounds reduces inflammation in an in vivo mouse model

Electrical signaling plays a crucial role in the cellular response to tissue injury in wound healing and an external electric field (EF) may expedite the healing process. Here, we have developed a standalone, wearable, and programmable electronic device to administer a well-controlled exogenous EF, aiming to accelerate wound healing in an in vivo mouse model to provide pre-clinical evidence. We monitored the healing process by assessing the re-epithelization rate and the ratio of M1/M2 macrophage phenotypes through histology staining. Following three days of treatment, the M1/M2 macrophage ratio decreased by 30.6% and the re-epithelization in the EF-treated wounds trended towards a non-statically significant 24.2% increase compared to the control. These findings provide point towards the effectiveness of the device in shortening the inflammatory phase by promoting reparative macrophages over inflammatory macrophages, and in speeding up re-epithelialization. Our wearable device supports the rationale for the application of programmed EFs for wound management in vivo and provides an exciting basis for further development of our technology based on the modulation of macrophages and inflammation to better wound healing.

Extremely low frequency-electromagnetic fields promote chondrogenic differentiation of adipose-derived mesenchymal stem cells through a conventional genetic program

Progressive cartilage deterioration leads to chronic inflammation and loss of joint function, causing osteoarthritis (OA) and joint disease. Although symptoms vary among individuals, the disease can cause severe pain and permanent disability, and effective therapies are urgently needed. Human Adipose-Derived Stem Cells (ADSCs) may differentiate into chondrocytes and are promising for treating OA. Moreover, recent studies indicate that electromagnetic fields (EMFs) could positively affect the chondrogenic differentiation potential of ADSCs. In this work, we investigated the impact of EMFs with frequencies of 35 Hertz and 58 Hertz, referred to as extremely low frequency-EMFs (ELF-EMFs), on the chondrogenesis of ADSCs, cultured in both monolayer and 3D cell micromasses. ADSC cultures were daily stimulated for 36 min with ELF-EMFs or left unstimulated, and the progression of the differentiation process was evaluated by morphological analysis, extracellular matrix deposition, and gene expression profiling of chondrogenic markers. In both culturing conditions, stimulation with ELF-EMFs did not compromise cell viability but accelerated chondrogenesis by enhancing the secretion and deposition of extracellular matrix components at earlier time points in comparison to unstimulated cells. This study showed that, in an appropriate chondrogenic microenvironment, ELF-EMFs enhance chondrogenic differentiation and may be an important tool for supporting and accelerating the treatment of OA through autologous adipose stem cell therapy.

Adjunctive Use of Bone Growth Stimulation Increases Cervical Spine Fusion Rates in Patients at Risk for Pseudarthrosis

STUDY DESIGN

A prospective multicenter clinical trial (NCT03177473) was conducted with a retrospective cohort used as a control arm.

OBJECTIVE

The purpose of this study was to evaluate cervical spine fusion rates in subjects with risk factors for pseudarthrosis who received pulsed electromagnetic field (PEMF) treatment.

SUMMARY OF BACKGROUND DATA

Certain risk factors predispose patients to pseudarthrosis, which is associated with prolonged pain, reduced function, and decreased quality of life.

METHODS

Subjects in the PEMF group were treated with PEMF for 6 months postoperatively. The primary outcome measure was fusion status at the 12-month follow-up period. Fusion status was determined using anterior/posterior, lateral, and flexion/extension radiographs and computed tomography (without contrast).

RESULTS

A total of 213 patients were evaluated (PEMF, n=160; Control, n=53). At baseline, the PEMF group had a higher percentage of subjects who used nicotine ( P =0.01), had osteoporosis ( P <0.05), multi-level disease ( P <0.0001), and were >65 years of age ( P =0.01). The PEMF group showed over two-fold higher percentage of subjects that had ≥3 risk factors (n=92/160, 57.5%) compared with the control group (n=14/53, 26.4%). At the 12-month follow-up, the PEMF group demonstrated significantly higher fusion rates compared with the control (90.0% vs. 60.4%, P <0.05). A statistically significant improvement in fusion rate was observed in PEMF subjects with multi-level surgery ( P <0.0001) and high BMI (>30 kg/m 2 ; P =0.0021) when compared with the control group. No significant safety concerns were observed.

CONCLUSIONS

Adjunctive use of PEMF stimulation provides significant improvements in cervical spine fusion rates in subjects having risk factors for pseudarthrosis. When compared with control subjects that did not use PEMF stimulation, treated subjects showed improved fusion outcomes despite being older, having more risk factors for pseudarthrosis, and undergoing more complex surgeries.

Clavicle fracture and triathlon performance: a case report

BACKGROUND

Collarbone fracture is a common injury, particularly among athletes involved in contact sports and participating in endurance activities. Conventional treatment requires surgery and postoperative immobilization, resulting in an average return-to-sport timeframe of approximately 13 weeks. This case challenges the established treatment protocols, aiming to expedite recovery and enable a quicker resumption of high-intensity athletic activities.

CASE PRESENTATION

A 24-year-old Caucasian athlete completed a Half-Ironman Triathlon (70.3) merely three weeks post-collarbone fracture. Utilizing Extracorporeal Magneto-Transduction Therapy (EMTT) alongside surgical intervention, the patient achieved accelerated healing and remarkable performance outcomes without encountering any adverse effects.

CONCLUSIONS

The integration of EMTT into the treatment paradigm for bone fractures alters the traditional understanding of recovery timelines and rehabilitation strategies. This case highlights the potential benefits of electromagnetic wave therapy in expediting the healing process and enabling athletes to resume high-level sports activities at an earlier stage.

Promising application of pulsed electromagnetic fields on tissue repair and regeneration

Tissue repair and regeneration is a vital biological process in organisms, which is influenced by various internal mechanisms and microenvironments. Pulsed electromagnetic fields (PEMFs) are becoming a potential medical technology due to its advantages of effectiveness and non-invasiveness. Numerous studies have demonstrated that PEMFs can stimulate stem cell proliferation and differentiation, regulate inflammatory reactions, accelerate wound healing, which is of great significance for tissue regeneration and repair, providing a solid basis for enlarging its clinical application. However, some important issues such as optimal parameter system and potential deep mechanisms remain to be resolved due to PEMFs window effect and biological complexity. Thus, it is of great importance to comprehensively summarizing and analyzing the literature related to the biological effects of PEMFs in tissue regeneration and repair. This review expounded the biological effects of PEMFs on stem cells, inflammation response, wound healing and musculoskeletal disorders in order to improve the application value of PEMFs in medicine. It is believed that with the continuous exploration of biological effects of PEMFs, it will be applied increasingly widely to tissue repair and other diseases.

Pulsed Electromagnetic Field Stimulation in Lumbar Spine Fusion for Patients With Risk Factors for Pseudarthrosis

BACKGROUND

Lumbar spinal fusion surgeries are increasing steadily due to an aging and ever-growing population. Patients undergoing lumbar spinal fusion surgery may present with risk factors that contribute to complications, pseudarthrosis, prolonged pain, and reduced quality of life. Pulsed electromagnetic field (PEMF) stimulation represents an adjunct noninvasive treatment intervention that has been shown to improve successful fusion and patient outcomes following spinal surgery.

METHODS

A prospective, multicenter study investigated PEMF as an adjunct therapy to lumbar spinal fusion procedures in patients at risk for pseudarthrosis. Patients with at least 1 of the following risk factors were enrolled: prior failed fusion, multilevel fusion, nicotine use, osteoporosis, or diabetes. Fusion status was determined by radiographic imaging, and patient-reported outcomes were also evaluated.

RESULTS

A total of 142 patients were included in the analysis. Fusion status was assessed at 12 months follow-up where 88.0% (n = 125/142) of patients demonstrated successful fusion. Fusion success for patients with 1, 2+, or 3+ risk factors was 88.5%, 87.5%, and 82.3%, respectively. Significant improvements in patient-reported outcomes using the Short Form 36, EuroQol 5 Dimension (EQ-5D) survey, Oswestry Disability Index, and visual analog scale for back and leg pain were also observed compared with baseline scores (P < 0.001). A favorable safety profile was observed. PEMF treatment showed a positive benefit-risk profile throughout the 6-month required use period.

CONCLUSIONS

The addition of PEMF as an adjunct treatment in patients undergoing lumbar spinal surgery provided a high rate of successful fusion with significant improvements in pain, function, and quality of life, despite having risk factors for pseudarthrosis.

CLINICAL RELEVANCE

PEMF represents a useful tool for adjunct treatment in patients who have undergone lumbar spinal surgery. Treatment with PEMF may result in improved fusion and patient-reported outcomes, regardless of risk factors.

TRIAL REGISTRATION

NCT03176303.

Electrical, Electromagnetic, Ultrasound Wave Therapies, and Electronic Implants for Neuronal Rejuvenation, Neuroprotection, Axonal Regeneration, and IOP Reduction

The peripheral nervous system (PNS) of mammals and nervous systems of lower organisms possess significant regenerative potential. In contrast, although neural plasticity can provide some compensation, the central nervous system (CNS) neurons and nerves of adult mammals generally fail to regenerate after an injury or damage. However, use of diverse electrical, electromagnetic and sonographic energy waves are illuminating novel ways to stimulate neuronal differentiation, proliferation, neurite growth, and axonal elongation/regeneration leading to various levels of functional recovery in animals and humans afflicted with disorders of the CNS, PNS, retina, and optic nerve. Tools such as acupuncture, electroacupuncture, electroshock therapy, electrical stimulation, transcranial magnetic stimulation, red light therapy, and low-intensity pulsed ultrasound therapy are demonstrating efficacy in treating many different maladies. These include wound healing, partial recovery from motor dysfunctions, recovery from ischemic/reperfusion insults and CNS and ocular remyelination, retinal ganglion cell (RGC) rejuvenation, and RGC axonal regeneration. Neural rejuvenation and axonal growth/regeneration processes involve activation or intensifying of the intrinsic bioelectric waves (action potentials) that exist in every neuronal circuit of the body. In addition, reparative factors released at the nerve terminals and via neuronal dendrites (transmitter substances), extracellular vesicles containing microRNAs and neurotrophins, and intercellular communication occurring via nanotubes aid in reestablishing lost or damaged connections between the traumatized tissues and the PNS and CNS. Many other beneficial effects of the aforementioned treatment paradigms are mediated via gene expression alterations such as downregulation of inflammatory and death-signal genes and upregulation of neuroprotective and cytoprotective genes. These varied techniques and technologies will be described and discussed covering cell-based and animal model-based studies. Data from clinical applications and linkage to human ocular diseases will also be discussed where relevant translational research has been reported.

The Effects of "Physical BEMER® Vascular Therapy" on Work Performed During Repeated Wingate Sprints

Purpose: The purpose of this study was to investigate the effects of Bio-Electro-Magnetic-Energy-Regulation (BEMER) on recovery and performance parameters in anaerobic exercise compared to active and passive recovery. Method: Fifteen recreationally active participants completed four sessions separated by 2-5 days between each session. The first visit involved one Wingate Anaerobic Test (WAnT; 30-s cycling sprint on a Monark ergometer) to familiarize participants with testing procedures. The three subsequent sessions involved four repeated WAnTs. Each sprint was followed by 4 min of either passive recovery (laying supine), active recovery (pedaling at 50 rpm at 20% of sprint workload), or BEMER recovery (laying supine on the BEMER body pad at intensity level "5-Plus."). The same recovery method was used within each testing session, and recovery method order was randomized across participants. Results: There was no difference in peak power, average power, fatigue index, or average work performed between recovery conditions. Active recovery resulted in a statistically significant decrease in ratings of pain intensity (M = -0.767, SD = 0.928) and pain unpleasantness (M = -0.608, SD = 0.915), from the first minute to the fourth minute of recovery, compared to both BEMER (Intensity: M = 0.675, SD = 0.745, Unpleasantness: M = 1.125, SD = 0.862) and passive (Intensity: M = 0.542, SD = 0.774, Unpleasantness: M = 1.018, SD = 0.872) recoveries, where pain ratings increased. Conclusions: Although no recovery method resulted in increased performance, active recovery led to a more comfortable exercise experience while still allowing comparable exercise performance.

The effect of bio-electro-magnetic-energy-regulation therapy on sleep duration and sleep quality among elite players in Norwegian women's football

The current study investigated if physical loads peak on game days and if Bio-Electro-Magnetic-Energy-Regulation (BEMER) therapy is affecting sleep duration and sleep quality on nights related to game nights among elite players in Norwegian women's elite football. The sample included 21 female football players from an elite top series club with a mean age of ~24 years (± 2.8). Sleep was measured every day over a period of 273 consecutive days with a Somnofy sleep monitor based on ultra-wideband (IR-UWB) pulse radar and Doppler technology. The current study was conducted as a quasi-experiment, where each player was their own control based on a control period that lasted for 3 months, and an experimental period that lasted for 5 months. Accordantly, the time each player spent with BEMER therapy was used as a control variable. Multivariate analyses of variance using FFMANOVA and univariate ANOVA with False Discovery Rate adjusted p-values show that physical performance (total distance, distance per minute, sprint meters >22.5 kmh, accelerations and decelerations) significantly peak on game day compared with ordinary training days and days related to game days. The results also show that sleep quantity and quality are significantly reduced on game night, which indicate disturbed sleep caused by the peak in physical load. Most sleep variables significantly increased in the experiment period, where BEMER therapy was used, compared to the control period before the introduction of BEMER therapy. Further, the analyses show that players who spent BEMER therapy >440 h had the most positive effects on their sleep, and that these effects were significantly compared to the players who used BEMER therapy <440 h. The findings are discussed based on the function of sleep and the different sleep stages have on recovery.

Prospects of magnetically based approaches addressing inflammation in tendon tissues

Tendon afflictions constitute a significant share of musculoskeletal diseases and represent a primary cause of incapacity worldwide. Unresolved/chronic inflammatory states have been associated with the onset and progression of tendon disorders, contributing to undesirable immune stimulation and detrimental tissue effects. Thus, targeting persistent inflammatory events could assist important developments to solve pathophysiological processes and innovative therapeutics to address impaired healing and accomplish complete tendon regeneration. This review overviews the impact of inflammation and inflammatory mediators in tendon niches, unveiling the importance of tendon cell populations and their signature features, and the influence of microenvironmental factors on inflamed and injured tendons. The demand for non-invasive instructive strategies to manage persistent inflammatory mediators, guide inflammatory pathways, and modulate cellular responses will also be approached by exploring the role of pulsed electromagnetic field (PEMF). PEMF alone or combined with more sophisticated systems triggered by magnetic fields will be considered in the design of successful therapies to control inflammation in tendinopathic conditions.

Modulation of Heart Rate Variability following PAP Ion Magnetic Induction Intervention in Subjects with Chronic Musculoskeletal Pain: A Pilot Randomized Controlled Study

Heart rate variability (HRV) analysis has emerged as a simple and non-invasive technique to indirectly evaluate the autonomic nervous system (ANS), and it is considered a sensible and advanced index of health status. Pulsed electromagnetic fields (PEMFs) are widely used in clinical settings for improving the health status of individuals with chronic musculoskeletal pain. The aim of the present single-blind, randomized, placebo-controlled parallel pilot study was to investigate the acute effect of a single session of PEMFs stimulation by a PAP ion magnetic induction (PAPIMI) device on ANS activity, as measured by HRV, in patients with chronic musculoskeletal pain, and compare such effect with that induced by a sham (control) PAPIMI inductor. Thirty-two patients were randomized into two groups: PAPIMI intervention (PAP) (n = 17) and sham PAPIMI intervention (SHAM-PAP) (n = 15). HRV was assessed before and following the interventions. The PAP group showed a significant increase in all values of the time-domain parameters (SDNN, RMSSD, NN50, and pNN50) and the HF component of HRV, suggesting a parasympathetic effect. In contrast, the SHAM-PAP group showed no significant differences in all HRV indices following the intervention. Preliminary findings suggested that PAPIMI inductor could influence ANS activity and provided initial evidence of the potential physiological response induced by the PAPIMI device.

Pulsed Electromagnetic Field (PEMF) Treatment Ameliorates Murine Model of Collagen-Induced Arthritis

Rheumatoid arthritis (RA) is an autoimmune disease of the joint synovial membranes. RA is difficult to prevent or treat; however, blocking proinflammatory cytokines is a general therapeutic strategy. Pulsed electromagnetic field (PEMF) is reported to alleviate RA's inflammatory response and is being studied as a non-invasive physical therapy. In this current study, PEMF decreased paw inflammation in a collagen-induced arthritis (CIA) murine model. PEMF treatment at 10 Hz was more effective in ameliorating arthritis than at 75 Hz. In the PEMF-treated CIA group, the gross inflammation score and cartilage destruction were lower than in the untreated CIA group. The CIA group treated with PEMF also showed lower serum levels of IL-1β but not IL-6, IL-17, or TNF-α. Serum levels of total anti-type II collagen IgG and IgG subclasses (IgG1, IgG2a, and IgG2b) remained unchanged. In contrast, tissue protein levels of IL-1β, IL-6, TNF-α, receptor activator of nuclear factor kappa-Β (RANK), RANK ligand (RANKL), IL-6 receptor (IL-6R), and TNF-α receptor1 (TNFR1) were all lower in the ankle joints of the PEMF-treated CIA group compared with the CIA group. The results of this study suggest that PEMF treatment can preserve joint morphology cartilage and delay the occurrence of CIA. PEMF has potential as an effective adjuvant therapy that can suppress the progression of RA.

The Effect of Different Frequencies of Pulsed Electromagnetic Fields on Cartilage Repair of Adipose Mesenchymal Stem Cell-Derived Exosomes in Osteoarthritis

BACKGROUND

The intra-articular injection of mesenchymal stem cell (MSC)-derived exosomes has already been proved to reverse osteoarthritic cartilage degeneration. Pulsed electromagnetic field (PEMF) has been found to regulate the biogenic function of MSCs. However, the effect of PEMF on MSC-derived exosomes has not yet been characterized. The aim of this study was to elucidate the regulatory role of different frequencies of PEMF in promoting the osteoarthritic cartilage regeneration of MSC-derived exosomes.

METHODS

The adipose tissue-derived MSCs (AMSCs) were extracted from the epididymal fat of healthy rats and further exposed to the PEMF at 1 mT amplitude and a frequency of 15, 45, and 75 Hz, respectively, in an incubator. The chondrocytes were treated with interlukin-1β (IL-1β) and the regenerative effect of co-culturing with PEMF-exposed AMSC-derived exosomes was assessed via Western blot, quantitative polymerase chain reaction, and ELISA assays. A rat model of osteoarthritis was established by anterior cruciate ligament transection (ACLT) surgery and received 4 times intra-articular injection of PEMF-exposed AMSC-derived exosomes once a week. After 8 weeks, the knee joint specimens of rats were collected for micro-computed tomography and histologic analyses.

RESULTS

PEMF-exposed AMSC-derived exosomes could be endocytosed with IL-1β-induced chondrocytes. Compared with the AMSC-derived exosomes alone, the PEMF-exposed AMSC-derived exosomes substantially suppressed the inflammation and extracellular matrix degeneration of IL-1β-induced chondrocytes as shown by higher expression of transcripts and proteins of COL2A1, SOX9, and ACAN and lower expression of MMP13 and caspase-1. Of these, the 75-Hz PEMF presented a more significant inhibitive effect than the 15-Hz and 45-Hz PEMFs. Furthermore, the intra-articular injection of 75-Hz PEMF-exposed exosomes could obviously increase the number of tibial epiphyseal trabeculae, lead to a remarkable decrease in Osteoarthritis Research Society International score, and upregulate the COL2A1 and ACAN protein level of the degenerated cartilage.

CONCLUSION

The present study demonstrated that PEMF stimulation could effectively promote the regeneration effects of AMSC-derived exosomes on osteoarthritic cartilage. Compared with other frequency parameters, the PEMF at a frequency of 75 Hz showed a superior positive effect on AMSC-derived exosomes in suppressing the IL-1β-induced chondrocyte inflammation and extracellular matrix catabolism, as well as the osteoarthritic cartilage degeneration.

Pulsed Electromagnetic Field Therapy for Pain Management in Interstitial Cystitis/Bladder Pain Syndrome: A Proof-of-Concept Case Series

OBJECTIVE

To evaluate the efficacy of pulsed electromagnetic field (PEMF) therapy for symptom and pain management in women with non-bladder centric interstitial cystitis/bladder pain syndrome (IC/BPS).

METHODS

Women with non-bladder centric IC/BPS and a numeric rating scale score for pelvic pain ≥6 underwent twice-daily 8-minute full body PEMF therapy sessions for 4 weeks. The primary outcome metric was a reduction in pelvic pain score ≥2 points. A 7-day voiding diary (collected at baseline and conclusion), 3 validated symptom scores, and the Short Form-36 Quality of Life questionnaire (completed at baseline, conclusion of treatment, and 8-week follow-up), were used to assess secondary outcomes. Treatment effects were analyzed via Wilcoxon-signed rank test; P < .05 was considered significant.

RESULTS

The 4-week treatment protocol was completed by 8 of 10 enrolled patients, and 7:8 (87.5%) had a significant reduction in pelvic pain (-3.0 points, P = .011) after 4 weeks. There was also a significant decrease in scores on all validated IC/BPS questionnaires, daily number of voids, and nocturia symptom score (P < .05). Significant increases in several quality-of-life questionnaire sub-scores were also identified at 4 weeks (P < .05). At 8-week post-therapy, the positive effects were somewhat attenuated, yet 4:8 patients (50%) continued to have significant pain reduction (P = .047). No adverse events or side effects were reported.

CONCLUSION

Whole body pulsed electromagnetic field therapy is an alternative treatment option for women with chronic bladder pain syndrome that warrants investigation through comparative trials.

Effectiveness of pulsed electromagnetic field therapy in the management of complex regional pain syndrome type 1: A randomized-controlled trial

Objectives: This study aims to investigate whether pulsed electromagnetic field (PEMF) therapy in addition to a conventional rehabilitation program is effective on pain and functioning in patients with type 1 complex regional pain syndrome (CRPS-1) of the hand.

Patients and methods: Between March 2013 and January 2015, a total of 32 patients (16 males, 16 females; mean age: 50.1±13.1 years; range, 25 to 75 years) were included. The patients were randomly allocated into two groups. The control group (n=16) received a conventional rehabilitation program consisting of physical modalities, exercises, and occupational therapy, whereas the PEMF group (n=16) received additional PEMF (8 Hz, 3.2 mT) to the affected hand. The primary outcome measure was pain intensity using the Numeric Rating Scale (NRS). Secondary outcome measures were grip and pinch strength, hand edema, hand dexterity, and hand activities. All patients received 20 therapy sessions (five sessions/week, four weeks in total) and were evaluated before and after the therapy and at the first-month follow-up.

Results: Both groups showed significant improvements in primary and secondary outcomes (p<0.05) after the therapy and at follow-up. When the groups were compared in terms of improvements in assessment parameters, no statistically significant difference was found between the two groups in any of the outcomes (p>0.05).

Conclusion: The PEMF in addition to conventional rehabilitation program did not provide additional benefit for pain and hand functions in CRPS-1. Future studies using different application parameters such as frequency, intensity, duration, and route may provide a better understanding of the role of PEMF in CRPS-1 treatment.

Electromagnetic field exposure as a plausible approach to enhance the proliferation and differentiation of mesenchymal stem cells in clinically relevant scenarios

Mesenchymal stem/stromal cell (MSC)‍-based therapy has been regarded as one of the most revolutionary breakthroughs in the history of modern medicine owing to its myriad of immunoregulatory and regenerative properties. With the rapid progress in the fields of osteo- and musculoskeletal therapies, the demand for MSC-based treatment modalities is becoming increasingly prominent. In this endeavor, researchers around the world have devised new and innovative techniques to support the proliferation of MSCs while minimizing the loss of hallmark features of stem cells. One such example is electromagnetic field (EMF) exposure, which is an alternative approach with promising potential. In this review, we present a critical discourse on the efficiency, practicability, and limitations of some of the relevant methods, with insurmountable evidence backing the implementation of EMF as a feasible strategy for the clinically relevant expansion of MSCs.

Effect of pulsed electromagnetic fields stimulation on ischemic skin model

This study aimed to evaluate the effect of Pulsed Electromagnetic Fields (PEMF) in improving blood flow reduction and tissue necrosis of ischemic animal induced by skin flap. In each experiment, twenty rats (280-320 g) were randomly divided into control group (n = 10) and PEMF (n = 10) group. All of the rats were performed skin flap in back. In the PEMF group, PEMF (1 Hz, 10 mT) was performed in each experiment. In Experiment-1 (n = 20), PEMF was performed for 90 minutes. In Experiment-2 (n = 20), additionally, a blocking film was inserted, and suture was performed to induce necrosis. PEMF was performed for 30 minutes each day for 7 days. As a result of Speckle-Flow Index (SFI) analysis, in the control group, blood flow continued to decrease immediately after the procedure. In the PEMF group, blood flow was remained constant after 30 minutes and increased after 60 minutes. The blood flow in a specific region substantially increased from the initial state. As a result of skin necrosis analysis, the progression rate in the PEMF group was slower than that of the control group. The rate of necrosis in the PEMF group decreased dramatically from the 6th day, and there was a statistically significant difference between the two groups at the 7th day (p < .05). In this study, it was confirmed that PEMF (1 Hz, 10 mT) has a blood flow improvement and skin tissue necrosis alleviation in the ischemic flap animal model.

Anti-Oxidative and Immune Regulatory Responses of THP-1 and PBMC to Pulsed EMF Are Field-Strength Dependent

Innate immune cells react to electromagnetic fields (EMF) by generating reactive oxygen species (ROS), crucial intracellular messengers. Discrepancies in applied parameters of EMF studies, e.g., flux densities, complicate direct comparison of downstream anti-oxidative responses and immune regulatory signaling. We therefore compared the impact of different EMF flux densities in human leukemic THP1 cells and peripheral blood mononuclear cells (PBMC) of healthy donors to additionally consider a potential disparate receptivity based on medical origin. ROS levels increased in THP1 cells stimulated with lipopolysaccharide (LPS) after one hour of EMF exposure. Moreover, weak EMF mitigated the depletion of the reducing agent NAD(P)H in THP1. Neither of these effects occurred in PBMC. Landscaping transcriptional responses to varied EMF revealed elevation of the anti-oxidative enzymes PRDX6 (2-fold) and DHCR24 (6-fold) in THP1, implying involvement in lipid metabolism. Furthermore, our study confirmed anti-inflammatory effects of EMF by 6-fold increased expression of IL10. Strikingly, THP1 responded to weak EMF, while PBMC were primarily affected by strong EMF, yet with severe cellular stress and enhanced rates of apoptosis, indicated by HSP70 and caspase 3 (CASP3). Taken together, our results emphasize an altered susceptibility of immune cells of different origin and associate EMF-related effects with anti-inflammatory signaling and lipid metabolism.

Human tendon-derived cell sheets created by magnetic force-based tissue engineering hold tenogenic and immunomodulatory potential

Cell sheet technology and magnetic based tissue engineering hold the potential to become instrumental in developing magnetically responsive living tissues analogues that can be potentially used both for modeling and therapeutical purposes. Cell sheet constructions more closely recreate physiological niches, through the preservation of contiguous cells and cell-ECM interactions, which assist the cellular guidance in regenerative processes. We herein propose to use magnetically assisted cell sheets (magCSs) constructed with human tendon-derived cells (hTDCs) and magnetic nanoparticles to study inflammation activity upon magCSs exposure to IL-1β, anticipating its added value for tendon disease modeling. Our results show that IL-1β induces an inflammatory profile in magCSs, supporting its in vitro use to enlighten inflammation mediated events in tendon cells. Moreover, the response of magCSs to IL-1β is modulated by pulsed electromagnetic field (PEMF) stimulation, favoring the expression of anti-inflammatory genes, which seems to be associated to MAPK(ERK1/2) pathway. The anti-inflammatory response to PEMF together with the immunomodulatory potential of magCSs opens new perspectives for their applicability on tendon regeneration that goes beyond advanced cell based modeling. STATEMENT OF SIGNIFICANCE: The combination of cell sheets and magnetic-based technologies holds promise as instrumental bio-instructive tools both for tendon disease modelling and for the development of magnetically responsive living tendon substitutes. We have previously shown that remote actuation of a pulsed electromagnetic field (PEMF) modulated the inflammatory response of IL-1β-treated human tendon-derived cell (hTDCs) monolayers. As magnetic cell sheets (magCSs) technologies enable improved cellular organization and matrix deposition, these constructions could better recapitulate tendon niches. In this work, we aimed to apply magCSs technologies to study hTDCs responses in inflammatory environments. Overall results show that PEMF-stimulated-magCSs hold evidence for immunomodulatory properties and to become a living tendon model envisioning tendon regenerative therapies.

Therapeutic application of light and electromagnetic fields to reduce hyper-inflammation triggered by COVID-19

COVID-19 - related morbidity is associated with exaggerated inflammation and cytokine production in the lungs, leading to acute respiratory failure. The cellular mechanisms underlying these so-called 'cytokine storms' are regulated through the Toll-like receptor 4 (TLR4) signaling pathway and by ROS (Reactive Oxygen Species). Both light (Photobiomodulation) and magnetic fields (e.g., Pulsed Electro Magnetic Field) stimulation are noninvasive therapies known to confer anti-inflammatory effects and regulate ROS signaling pathways. Here we show that daily exposure to two 10-minute intervals of moderate intensity infra-red light significantly lowered the inflammatory response induced via the TLR4 receptor signaling pathway in human cell cultures. Anti-inflammatory effects were likewise achieved by electromagnetic field exposure of cells to daily 10-minute intervals of either Pulsed Electromagnetic Fields (PEMF), or to Low-Level static magnetic fields. Because current illumination and electromagnetic field therapies have no known side effects, and are already approved for some medical uses, we have here developed protocols for verification in clinical trials of COVID-19 infection. These treatments are affordable, simple to implement, and may help to resolve the acute respiratory distress of COVID-19 patients both in the home and in the hospital.

Magnetic triggers in biomedical applications - prospects for contact free cell sensing and guidance

In recent years, the inputs from magnetically assisted strategies have been contributing to the development of more sensitive screening methods and precise means of diagnosis to overcome existing and emerging treatment challenges. The features of magnetic materials enabling in vivo traceability, specific targeting and space- and time-controlled delivery of nanomedicines have highlighted the resourcefulness of the magnetic toolbox for biomedical applications and theranostic strategies. The breakthroughs in magnetically assisted technologies for contact-free control of cell and tissue fate opens new perspectives to improve healing and instruct regeneration reaching a wide range of diseases and disorders. In this review, the contribution of magnetic nanoparticles (MNPs) will be explored as sophisticated and versatile nanotriggers, evidencing their unique cues to probe and control cell function. As cells detect and engage external magnetic features, these approaches will be overviewed considering molecular engineering and cell programming perspectives as well as cell and tissue targeting modalities. The therapeutic relevance of MNPs will be also emphasized as key components of nanostructured systems to control the release of nanomedicines and in the context of new therapy technologies.

Magnetic responsive materials modulate the inflammatory profile of IL-1β conditioned tendon cells

Tendinopathies represent half of all musculoskeletal injuries worldwide. Inflammatory events contribute to both tendon healing and to tendinopathy conditions but the cellular triggers leading to one or the other are unknown. In previous studies, we showed that magnetic field actuation modulates human tendon cells (hTDCs) behavior in pro-inflammatory environments, and that magnetic responsive membranes could positively influence inflammation responses in a rat ectopic model. Herein, we propose to investigate the potential synergistic action of the magnetic responsive membranes, made of a polymer blend of starch with polycaprolactone incorporating magnetic nanoparticles (magSPCL), and the actuation of pulsed electromagnetic field (PEMF): 5 Hz, 4mT of intensity and 50% of duty cycle, in IL-1β-treated-hTDCs, and in the immunomodulatory response of macrophages. It was found that the expression of pro-inflammatory (TNFα, IL-6, IL-8, COX-2) and ECM remodeling (MMP-1,-2,-3) markers tend to decrease in cells cultured onto magSPCL membranes under PEMF, while the expression of TIMP-1 and anti-inflammatory genes (IL-4, IL-10) increases. Also, CD16⁺⁺ and CD206⁺ macrophages were only found on magSPCL membranes with PEMF application. Magnetic responsive membranes show a modulatory effect on the inflammatory profile of hTDCs favoring anti-inflammatory cues which is also supported by the anti-inflammatory/repair markers expressed in macrophages. These results suggest that magnetic responsive magSPCL membranes can contribute for inflammation resolution acting on both resident cell populations and inflammatory cells, and thus significantly contribute to tendon regenerative strategies. Statement of significance Magnetically-assisted strategies have received great attention in recent years to remotely trigger and guide cell responses. Inflammation plays a key role in tendon healing but persistent pro-inflammatory molecules can contribute to tendon disorders, and therefore provide a therapeutic target for advanced treatments. We have previously reported that magnetic fields modulate the response of human tendon cells (hTDCs) conditioned to pro-inflammatory environments (IL-1β-treated-hTDCs), and that magnetic responsive membranes positively influence immune responses. In the present work, we combined pulsed electromagnetic field (PEMF) and magnetic responsive membranes to guide the inflammatory profile of IL-1β-treated-hTDCs and of macrophages. The results showed that the synergistic action of PEMF and magnetic membranes supports the applicability of magnetically actuated systems to regulate inflammatory events and stimulate tendon regeneration.

Magnetic Stimulation Drives Macrophage Polarization in Cell to-Cell Communication with IL-1β Primed Tendon Cells

Inflammation is part of the natural healing response, but it has been simultaneously associated with tendon disorders, as persistent inflammatory events contribute to physiological changes that compromise tendon functions. The cellular interactions within a niche are extremely important for healing. While human tendon cells (hTDCs) are responsible for the maintenance of tendon matrix and turnover, macrophages regulate healing switching their functional phenotype to environmental stimuli. Thus, insights on the hTDCs and macrophages interactions can provide fundamental contributions on tendon repair mechanisms and on the inflammatory inputs in tendon disorders. We explored the crosstalk between macrophages and hTDCs using co-culture approaches in which hTDCs were previously stimulated with IL-1β. The potential modulatory effect of the pulsed electromagnetic field (PEMF) in macrophage-hTDCs communication was also investigated using the magnetic parameters identified in a previous work. The PEMF influences a macrophage pro-regenerative phenotype and favors the synthesis of anti-inflammatory mediators. These outcomes observed in cell contact co-cultures may be mediated by FAK signaling. The impact of the PEMF overcomes the effect of IL-1β-treated-hTDCs, supporting PEMF immunomodulatory actions on macrophages. This work highlights the relevance of intercellular communication in tendon healing and the beneficial role of the PEMF in guiding inflammatory responses toward regenerative strategies.

Polypyrrole-Incorporated Conducting Constructs for Tissue Engineering Applications: A Review

Conductive polymers have recently attracted interest in biomedical applications because of their excellent intrinsic electrical conductivity and satisfactory biocompatibility. Polypyrrole (PPy) is one of the most popular among these conductive polymers due to its high conductivity under physiological conditions, and it can be chemically modified to allow biomolecules conjugation. PPy has been used in fabricating biocompatible stimulus-responsive scaffolds for tissue engineering applications, especially for repair and regeneration of electroactive tissues, such as the bone, neuron, and heart. This review provides a comprehensive overview of the basic properties and synthesis methods of PPy, as well as a summary of the materials that have been integrated with PPy. These composite scaffolds are comparatively evaluated with regard to their mechanical properties, biocompatibility, and usage in tissue engineering.

Electroconductive Nanobiomaterials for Tissue Engineering and Regenerative Medicine

Regenerative medicine aims to engineer tissue constructs that can recapitulate the functional and structural properties of native organs. Most novel regenerative therapies are based on the recreation of a three-dimensional environment that can provide essential guidance for cell organization, survival, and function, which leads to adequate tissue growth. The primary motivation in the use of conductive nanomaterials in tissue engineering has been to develop biomimetic scaffolds to recapitulate the electrical properties of the natural extracellular matrix, something often overlooked in numerous tissue engineering materials to date. In this review article, we focus on the use of electroconductive nanobiomaterials for different biomedical applications, particularly, very recent advancements for cardiovascular, neural, bone, and muscle tissue regeneration. Moreover, this review highlights how electroconductive nanobiomaterials can facilitate cell to cell crosstalk (i.e., for cell growth, migration, proliferation, and differentiation) in different tissues. Thoughts on what the field needs for future growth are also provided.