Use of bioelectric dressings for patients with hard-to-heal wounds: a case report

There are many types of dressings available for the management of hard-to-heal (chronic) wounds. This case report illustrates the efficacy of bioelectric dressings in healing hard-to-heal wounds in five patients. Of the patients, four had diabetic foot ulcers (DFUs) and one had a surgical site infection. Wounds were examined using the TIMES concept and debridement was carried out if needed. Amorphous hydrogel was used as conduction fluid before the application of the bioelectric wound dressings. The wound was covered with foam dressing and crepe bandage. In this case report, among all five wounds, one wound healed completely while the other four reduced in size, with the presence of more granulation and re-epithelialisation. In this case report, bioelectric wound dressings were effective in managing infection and promoting wound healing.

The impact of continuous electrical microcurrent on acute and hard-to-heal wounds: a systematic review

BACKGROUND

Wound infections result in considerable morbidity, mortality and healthcare costs. Antibiotic resistance has complicated wound healing, and new, non-antibiotic-based treatment methods are being developed.

AIMS

To evaluate evidence on the safety, efficacy and real-world effectiveness of electroceutical devices (ECDs) that provide continuous electrical stimulation to wounds.

METHOD

A systematic search was conducted to identify primary studies published between 2009 and 2019 that described therapeutic wound treatment using portable ECDs. Studies were included if the ECD delivered continuous electrical current directly to the wound area for the duration of treatment.

RESULTS

Of 171 citations identified in the search, 13 articles met the inclusion criteria and were analysed. Nine studies evaluated dressings embedded with zinc and silver particles that generated electricity electrochemically, and four evaluated electrode-based units with external batteries. ECDs were effective in healing complex, hard-to-heal wounds that had not responded to other treatments. Four studies showed that ECDs led to complete closure of wounds without complications, and in some cases healed wounds faster than standard of care (SOC). One study found that ECDs resulted in higher ratings by both patients and surgeons than SOC for the progression of wound healing and scar appearance. Additionally, three studies found ECD treatment was less expensive than SOC, due to patients requiring fewer dressing changes or nurse visits.

CONCLUSION

ECDs appeared to be a safe, effective and cost-effective method for treating severe, complex and challenging wounds, including hard-to-heal wounds, surgical incisions and skin graft donor sites.

A Novel Peptide-Based Antimicrobial Wound Treatment is Effective Against Biofilms of Multi-Drug Resistant Wound Pathogens

Wound infections are a common complication of combat-related injuries that significantly increase morbidity and mortality. Multi-drug resistant (MDR) organisms and their associated biofilms play a significant role in the pathogenicity and chronicity of wound infections. A critical barrier to progress in the treatment of traumatic wounds is the need for broad spectrum antimicrobials that are effective against biofilms and compatible with topical delivery. In this study, we present the in vitro efficacy of two de novo designed cationic, antimicrobial peptides and related topical formulations against single species and polymicrobial biofilms of MDR bacteria. Minimum biofilm eradication concentrations for peptides ranged from 0.7 μM for Staphylococcus aureus to 13.2 μM for Pseudomonas aeruginosa. Varying pH did not adversely impact peptide activity, however, in the presence of albumin, minimum biofilm eradication concentrations generally increased. When formulated into gels or dressings, both peptides eradicated mono- and polymicrobial biofilms of MDR pathogens. The biocompatibility index (BI) was found to be greater than one for both ASP-1 and ASP-2, with a slightly greater (more favorable) BI for ASP-2. The BIs for both peptides were greater than BIs previously reported for commonly used topical antimicrobial agents. The antimicrobial peptides and related formulations presented provide a promising platform for treatment of wound biofilms to improve outcomes for those injured in combat.

Antimicrobial activity of a bioelectric dressing using an in vitro wound pathogen colony drip-flow reactor biofilm model

OBJECTIVE

We performed in vitro antibiofilm testing of a silver and zinc containing microcurrent generating bioelectric dressing (BED) against clinical wound pathogens to determine its efficacy in preventing biofilm formation under low shear and continuous flow conditions, simulating wound infection environments.

METHOD

We customised an in vitro colony drip-flow reactor (DFR) biofilm model for efficacy evaluation of BED. Each bacterial pathogen was diluted to 10⁴CFU/ml and inoculated on the polycarbonate filter membrane as an abiotic support. BED and controls (no treatment, gauze, and blank polyester with no silver and zinc) were applied directly on the membranes where bacterial cultures were inoculated. Biofilms were continuously developed onto the membranes for 72 hours at room temperature. Biofilm formation was confirmed by crystal violet staining and microscopic observation. Through vigorous shaking and sonication, the released bacteria were serially diluted, plated, and incubated for 24 hours at 37°C to determine the numbers of surviving bacteria.

RESULTS

Biofilms were well developed onto blank polyesters, but not the BED after 72 hours incubation. Crystal violet staining from the blank polyesters showed large and fully grown biofilms. We observed an inhibition in bacterial growth on BED treatment. The antibiofilm activity of the BED against each of eight monospecies biofilms showed a 1- or 2 log10 (or 10- or 100-fold) reduction in bacterial numbers compared with those of controls.

CONCLUSION

Our results demonstrated that colony DFR biofilm model was an appropriate for testing the antibiofilm efficacy of BED under low shear and continuous flow conditions for simulating clinical wound environments. The bioelectric currents generated from the silver and zinc active ingredients in the dressing resulted in antibiofilm activity of this wound care device.

DECLARATION OF INTEREST

The opinions or assertions contained herein are the private views of the authors, based on scientific investigation, and are not to be construed as official or as reflecting the views of the Department of Defense, the United States Government or any of the authors' employers. Dr. Mina Izadjoo has served as a consultant to Vomaris Innovations Inc.

Bioelectric Silver-Zinc Dressing Equally Effective to Chlorhexidine in Reducing Skin Bacterial Load in Healthy Volunteers

PURPOSE

The aim of the present study was to evaluate and compare the effectiveness of the silver-zinc bioelectric dressing as compared with skin preparation with 2% chlorhexidine or 4% chlorhexidine in reducing the bacterial count on the knee.

METHODS

Three groups consisting of 48 healthy volunteers were included. Age range was 23 to 54 years old and 60% of participants were male. Each subject had 1 knee serve as the test and the contralateral as the control. The test site was prepared with either 2% chlorhexidine, 4% chlorhexidine, or a silver-zinc bioelectric dressing and after 24 hours skin cultures were taken and examined for bacterial growth.

RESULTS

In the 2% chlorhexidine group 23 of 48 unprepped knees had positive cultures, compared with 9 of 48 prepped knees (P = .003; risk reduction, 4.0 times). In the 4% chlorhexidine group 25 of 48 unprepped knees had positive cultures, compared with 14 of 48 prepped knees (P = .027; risk reduction, 2.6 times). In the silver-zinc bioelectric dressing group 29 of 48 unprepped knees had positive cultures, compared with 7 of 48 prepped knees (P < .001; risk reduction, 8.9 times). There was no difference in the positive skin culture rate between the 3 methods.

CONCLUSIONS

Application of the silver-zinc bioelectric dressing was equally effective at reducing skin bacterial load when compared with skin preparation with 2% chlorhexidine or 4% chlorhexidine in healthy volunteers.

LEVEL OF EVIDENCE

Basic Science - Microbiology.

CLINICAL RELEVANCE

The findings of this study indicate that the use of a bioelectric dressing after knee surgery can match the standard of care of preparing the skin with an antiseptic before surgery.

Lack of level I evidence on how to prevent infection after elective shoulder surgery

PURPOSE

Infection is a concern after all orthopedic procedures, including shoulder surgery. This systematic review of literature aimed to determine risk factors for infection as well as the availability and effectiveness of measures utilized to prevent infection after elective shoulder surgery.

METHODS

An electronic database search was performed using MEDLINE (1950-October 2017), EMBASE (1980-October 2017), CINAHL (1982-October 2017), and the Cochrane database to identify studies reporting a risk factor or preventive measure for infection after shoulder surgery.

RESULTS

Fifty-one studies were eligible for inclusion. Risk factors identified for infection were male sex, the presence of hair, receiving an intra-articular cortisone injection within the 3 months prior to surgery, smoking, obesity, and several comorbidities. The only preventive measure with level I evidence was for the use of chlorhexidine wipes for cleansing the skin in the days prior to surgery and for the use of ChloraPrep or DuraPrep over povodine and iodine to prep the skin at the time of surgery. Level II-IV evidence was found for other infection prevention methods such as intravenous antibiotic prophylaxis.

CONCLUSION

There are many risk factors associated with developing an infection after elective shoulder surgery. Many preventive measures have been described which may decrease the risk of infection; however, most lack a high level evidence to support them. The findings of this systematic review are clinically relevant as it has been shown that infection after shoulder surgery results in poor patient-reported outcomes and pose a significant financial burden. As surgeons the goal should be to prevent infections to avoid the morbidity for patients and the increased cost for society.

LEVEL OF EVIDENCE

IV systematic review of literature.

Electrically stimulated cell migration and its contribution to wound healing

Naturally occurring electric fields are known to be morphogenetic cues and associated with growth and healing throughout mammalian and amphibian animals and the plant kingdom. Electricity in animals was discovered in the eighteenth century. Electric fields activate multiple cellular signaling pathways such as PI3K/PTEN, the membrane channel of KCNJ15/Kir4.2 and intracellular polyamines. These pathways are involved in the sensing of physiological electric fields, directional cell migration (galvanotaxis, also known as electrotaxis), and possibly other cellular responses. Importantly, electric fields provide a dominant and over-riding signal that directs cell migration. Electrical stimulation could be a promising therapeutic method in promoting wound healing and activating regeneration of chronic and non-healing wounds. This review provides an update of the physiological role of electric fields, its cellular and molecular mechanisms, its potential therapeutic value, and questions that still await answers.

Wireless Microcurrent-Generating Antimicrobial Wound Dressing in Primary Total Knee Arthroplasty: A Single-Center Experience

The spread of multidrug-resistant bacteria and financial burden of periprosthetic joint infection (PJI) further the need for treatments to address pathogenic contamination and expedite healing. This retrospective study was a chart review of a series of 92 patients who underwent 100 total knee arthroplasties performed by the same surgeon and treated with a novel microcurrent-generating antimicrobial dressing (MCD). Mean hospital length of stay was 2.3±0.9 days, while the mean length of treatment with MCD was 8.3±1.2 days. No major complications, PJI or major infectious complications were reported, with two readmissions (2%) within 30 days of surgery. Knee Society Score function showed statistically significant improvements post-operatively, with a mean six-month score of 75.0±20.3 and mean change from baseline of 36.3±21.1 (P<0.0001). These results support previous findings that use of the MCD may result in improved outcomes as an element in post-operative wound management.

The Challenging World of Biofilm Physiology

Worldwide, infectious diseases are one of the leading causes of death among children. At least 65% of all infections are caused by the biofilm mode of bacterial growth. Bacteria colonise surfaces and grow as multicellular biofilm communities surrounded by a polymeric matrix as a common survival strategy. These sessile communities endow bacteria with high tolerance to antimicrobial agents and hence cause persistent and chronic bacterial infections, such as dental caries, periodontitis, otitis media, cystic fibrosis and pneumonia. The highly complex nature and the rapid adaptability of the biofilm population impede our understanding of the process of biofilm formation, but an important role for oxygen-binding proteins herein is clear. Much research on this bacterial lifestyle is already performed, from genome/proteome analysis to in vivo antibiotic susceptibility testing, but without significant progress in biofilm treatment or eradication. This review will present the multiple challenges of biofilm research and discuss possibilities to cross these barriers in future experimental studies.

Advanced Therapeutic Dressings for Effective Wound Healing--A Review

Advanced therapeutic dressings that take active part in wound healing to achieve rapid and complete healing of chronic wounds is of current research interest. There is a desire for novel strategies to achieve expeditious wound healing because of the enormous financial burden worldwide. This paper reviews the current state of wound healing and wound management products, with emphasis on the demand for more advanced forms of wound therapy and some of the current challenges and driving forces behind this demand. The paper reviews information mainly from peer-reviewed literature and other publicly available sources such as the US FDA. A major focus is the treatment of chronic wounds including amputations, diabetic and leg ulcers, pressure sores, and surgical and traumatic wounds (e.g., accidents and burns) where patient immunity is low and the risk of infections and complications are high. The main dressings include medicated moist dressings, tissue-engineered substitutes, biomaterials-based biological dressings, biological and naturally derived dressings, medicated sutures, and various combinations of the above classes. Finally, the review briefly discusses possible prospects of advanced wound healing including some of the emerging physical approaches such as hyperbaric oxygen, negative pressure wound therapy and laser wound healing, in routine clinical care.