Acetic acid dressings: Finding the Holy Grail for infected wound management

On the potential role of naturally occurring carboxylic organic acids as anti-infective agents: opportunities and challenges

Carboxylic organic acids are intermediates of central carbon metabolic pathways (e.g. acetic, propionic, citric, and lactic acid) long known to have potent antimicrobial potential, mainly at acidic pHs. The food industry has been leveraging those properties for years, using many of these acids as preservatives to inhibit the growth of pathogenic and/or spoilage fungal and bacterial species. A few of these molecules (the most prominent being acetic acid) have been used as antiseptics since Hippocratic medicine, mainly to treat infected wounds in patients with burns. With the growth of antibiotic therapy, the use of carboxylic acids (and other chemical antiseptics) in clinical settings lost relevance; however, with the continuous emergence of multi-antibiotic/antifungal resistant strains, the search for alternatives has intensified. This prospective article raises awareness of the potential of carboxylic acids to control infections in clinical settings, considering not only their previous exploitation in this context (which we overview) but also the positive experience of their safe use in food preservation. At a time of great concern with antimicrobial resistance and the slow arrival of new antimicrobial therapeutics to the market, further exploration of organic acids as anti-infective molecules may pave the way to more sustainable prophylactic and therapeutic approaches.

Biofilm therapy for chronic wounds

Chronic wounds have been a major factor of serious harm to global public health. At present, it is known that almost all chronic wounds contain biofilms, which seriously hinder the healing process. Removal of biofilms can effectively promote the healing of chronic wounds. As the study of wound biofilms deepens, many new treatment methods have emerged, thus bringing revolutionary means for the treatment of chronic wound biofilm. This review summarizes various methods for the treatment of chronic wound biofilm worldwide to provide a theoretical summary and practical basis for the selection of suitable wound biofilm treatment methods in clinical practice.

Exploitation of microbial activities at low pH to enhance planetary health

Awareness is growing that human health cannot be considered in isolation but is inextricably woven with the health of the environment in which we live. It is, however, under-recognized that the sustainability of human activities strongly relies on preserving the equilibrium of the microbial communities living in/on/around us. Microbial metabolic activities are instrumental for production, functionalization, processing, and preservation of food. For circular economy, microbial metabolism would be exploited to produce building blocks for the chemical industry, to achieve effective crop protection, agri-food waste revalorization, or biofuel production, as well as in bioremediation and bioaugmentation of contaminated areas. Low pH is undoubtedly a key physical-chemical parameter that needs to be considered for exploiting the powerful microbial metabolic arsenal. Deviation from optimal pH conditions has profound effects on shaping the microbial communities responsible for carrying out essential processes. Furthermore, novel strategies to combat contaminations and infections by pathogens rely on microbial-derived acidic molecules that suppress/inhibit their growth. Herein, we present the state-of-the-art of the knowledge on the impact of acidic pH in many applied areas and how this knowledge can guide us to use the immense arsenal of microbial metabolic activities for their more impactful exploitation in a Planetary Health perspective.

Comparative evaluation of therapeutic efficacy and safety of black peel versus 25% trichloroacetic acid peel in mild to moderate acne vulgaris: a split face study

Introduction

Peeling has withstood the test of time as a simple, minimally invasive method to renew the skin, despite the introduction of more advanced procedures like lasers.

Materials and Methods

Thirty patients (or 60 sites) with age ranging from 15 to 45 years with mild-to-moderate acne vulgaris were included in the study. Assessment at baseline was done by the global acne grading system score for including mild and moderate acne patients.

Results

On grading the improvement according to the 5-point Global Assessment Scale (GAS), it was found that in area A (black peel), 6.7% of patients showed excellent improvement, 86.7% of patients showed good improvement, and 6.7% of patients showed fair improvement. In area B (25%TCA peel), 6.7% of patients showed excellent improvement, 80% of patients showed good improvement, and 13.3% of patients showed fair improvement.

Discussion

None of the patients showed poor or worse outcomes in any of the areas. The difference between the groups was not significant (P = 0.688).

Conclusion

There is a paucity of data in the literature regarding the comparison of black peel with other conventional peels in the treatment of acne vulgaris. To the best of our knowledge, this is the first study comparing black peel with TCA peel in the treatment of acne vulgaris.

Smart Responsive and Controlled-Release Hydrogels for Chronic Wound Treatment

Chronic wounds are a major health challenge that require new treatment strategies. Hydrogels are promising drug delivery systems for chronic wound healing because of their biocompatibility, hydration, and flexibility. However, conventional hydrogels cannot adapt to the dynamic and complex wound environment, which involves low pH, high levels of reactive oxygen species, and specific enzyme expression. Therefore, smart responsive hydrogels that can sense and respond to these stimuli are needed. Crucially, smart responsive hydrogels can modulate drug release and eliminate pathological factors by changing their properties or structures in response to internal or external stimuli, such as pH, enzymes, light, and electricity. These stimuli can also be used to trigger antibacterial responses, angiogenesis, and cell proliferation to enhance wound healing. In this review, we introduce the synthesis and principles of smart responsive hydrogels, describe their design and applications for chronic wound healing, and discuss their future development directions. We hope that this review will inspire the development of smart responsive hydrogels for chronic wound healing.

The impact of wound pH on the antibacterial properties of Medical Grade Honey when applied to bacterial isolates present in common foot and ankle wounds. An in vitro study

BACKGROUND

Diabetic foot ulcers (DFUs) and post-surgical wound infections are amongst the most troublesome complications of diabetes and following foot and ankle surgery (FAS) respectively. Both have significant psychosocial and financial burden for both patients and the healthcare system. FAS has been reported to have higher than average post-surgical infections when compared to other orthopaedic subspecialties. Evidence also indicates that patients with diabetes and other co morbidities undergoing FAS are at a much greater risk of developing surgical site infections (SSIs). With the growing challenges of antibiotic resistance and the increasingly high numbers of resilient bacteria to said antibiotics, the need for alternative antimicrobial therapies has become critical.

AIM

The aim of this study was to investigate the use of medical grade honey (MGH) when altered to environments typically present in foot and ankle wounds including DFUs and post-surgical wounds (pH6-8).

METHODS

MGH (Activon) was altered to pH 6, 7 and 8 and experimental inoculums of Pseudomonas aeruginosa (NCTC10782), Escherichia coli, (NCTC10418), Staphylococcus aureus (NCTC10655) and Staphylococcus epidermidis (NCTC 5955) were transferred into each pH adjusted MGH and TSB solution and the positive and negative controls.

RESULTS

MGH adjusted to various pH values had the ability to reduce bacteria cell survival in all pH variations for all bacteria tested, with the most bacterial reduction/elimination noted for Staphylococcus epidermidis. No correlations were noted among the pH environments investigated and the colony counts, for which there were small amounts of bacteria survived.

CONCLUSION

This research would indicate that the antibacterial properties of honey remains the same regardless of the pH environment. MGH could therefore potentially be considered for use on non-infected foot and ankle wounds to reduce the bacterial bioburden, the risk of infections and ultimately to improve healing outcomes.

The Efficacy of Apple Cider Vinegar at Different pH Values as an Antimicrobial Agent: An In Vitro Study

AIMS AND BACKGROUND

This study evaluates the antimicrobial activities of commercially available 5% apple cider vinegar (ACV) against Enterococcus faecalis, Streptococcus mutans, and Lactobacillus casei. Materials and methods: Minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) were conducted using the broth microdilution method. Sodium hypochlorite (NaOCl) of 5.25% was used as a positive control, and comparisons were also made with acetic acid (AA) as the main ingredient in ACV. The three test bacteria treated with the most effective ACV dilution were visualized under a transmission electron microscope (TEM) for structural changes.

RESULTS

Minimal inhibitory concentration was determined at 0.625% of the concentration of ACV against S. mutans and E. faecalis and 1.25% of the concentration of ACV against L. casei with two-fold serial dilutions. A concentration of 5 × 10-1% with 10-fold serial dilutions was found to be the MIC value for all three bacteria. No significant differences were found when compared with the positive control (NaOCl) (p = 0.182, p = 0.171, and p = 0.234), respectively, for two-fold serial dilutions and (p = 1.000, p = 0.658, and p = 0.110), respectively for 10-fold serial dilutions. MBC was observed to be 5% ACV for both E. faecalis and S. mutans. However, positive microbial growth was observed on the agar plate when cultured with L. casei. An independent sample t-test showed no significant differences (p > 0.05) in the antimicrobial activities between 5% ACV and 5% pure AA. TEM revealed cell wall and cytoplasmic membrane disruptions on all three bacteria at MIC value.

CONCLUSION

Apple cider vinegar has antimicrobial activities against Enterococcus faecalis, Streptococcus mutans, and Lactobacillus casei at their respective MIC values.

CLINICAL SIGNIFICANCE

Apple cider vinegar can be an alternative antimicrobial dental pulp disinfectant to sodium hypochlorite. Apple cider vinegar can be used safely, especially in children's dental pulp therapy and deep caries management, when adequate tooth isolation is not readily achievable. Thus, adverse reactions commonly associated with other frequently used chemical disinfectants can be avoided.

Exploring STAT3 stimulatory potential of novel wound healing molecules by virtual screening and molecular dynamics simulations

STAT3 signaling is a major intrinsic pathway for cell proliferation owing to its frequent activation in injured tissues. Various STAT3-regulated genes encode cytokines and growth factors, the receptors of which in turn activate the same STAT3 pathways, thereby regulating cell proliferation. In present study, we aimed to analyze several compounds for their wound healing and tissue repair potential by computer-aided virtual screening and Molecular dynamics (MD) simulation. Based on literature studies, a total of 36 drug molecules were selected having critical functions in wound healing and tissue repair. The pharmacological features (ADME and toxicity) of these molecules were predicted to find lead molecules among them. Further, a comparative study was performed to screen binding efficiency of STAT3 with many conventional wound healers by molecular docking. Among all, W6S, Strychnin, Prednisone and N-(6-(4-(3-(4-((4-Methylpiperazin-1-yl) methyl)-3- (trifluoromethyl)phenyl)ureido)phenoxy)pyrimidin-4-yl)cyclopropanecarboxamide showed best docking with STAT3 protein. The calculated binding energy of these molecules with STAT3 was found to be -8.9 Kca/mol for N-(6-(4-(3-(4-((4-Methylpiperazin-1-yl) methyl)-3-(trifluoromethyl) phenyl)ureido)phenoxy)pyrimidin-4-yl)cyclopropanecarboxamide, -8.7 Kcal/mol for W6S, -8.5 Kcal/mol for Strychnine and -8.4 Kcal/mol for Prednisone . The result was reconsidered for MD simulation. The simulation result showed stable binding of the ligand with STAT3 protein for 100 ns. These compounds showed better interaction potential with STAT3 was compared to known tissue repair molecules. Our data paves way for further exploration of these molecules as novel cell proliferators to be tested in various types of wound and tissue injuries.Communicated by Ramaswamy H. Sarma.

Effectiveness of 1 and 2 per cent acetic acid solutions in the 2-week treatment of granular myringitis

OBJECTIVE

Granular myringitis is characterised by de-epithelialisation of the tympanic membrane. Patients present with intermittent otorrhoea, otalgia or itching. With improper or inadequate treatment, granular myringitis could cause ear canal fibrosis and stenosis. There are no standard topical ear drops for granular myringitis. Treatments have inconsistent success rates and variable timelines. This study aimed to compare the effectiveness of treating granular myringitis with 1 and 2 per cent acetic acid solutions for two weeks.

METHOD

This double-blind, randomised, controlled trial enrolled and randomly allocated 47 participants to 2 groups between October 2021 and June 2022.

RESULTS

After two weeks, the groups' treatment success rates did not differ significantly. There was a 10 per cent recurrence rate 8 weeks after treatment completion. All patients tolerated the diluted vinegar.

CONCLUSION

There is no difference in the efficacy of 1 and 2 per cent diluted vinegar in treating granular myringitis for two weeks.

Photodynamic Therapy, Probiotics, Acetic Acid, and Essential Oil in the Treatment of Chronic Wounds Infected with Pseudomonas aeruginosa

As a prevalent medical problem that burdens millions of patients across the world, chronic wounds pose a challenge to the healthcare system. These wounds, often existing as a comorbidity, are vulnerable to infections. Consequently, infections hinder the healing process and complicate clinical management and treatment. While antibiotic drugs remain a popular treatment for infected chronic wounds, the recent rise of antibiotic-resistant strains has hastened the need for alternative treatments. Future impacts of chronic wounds are likely to increase with aging populations and growing obesity rates. With the need for more effective novel treatments, promising research into various wound therapies has seen an increased demand. This review summarizes photodynamic therapy, probiotics, acetic acid, and essential oil studies as developing antibiotic-free treatments for chronic wounds infected with Pseudomonas aeruginosa. Clinicians may find this review informative by gaining a better understanding of the state of current research into various antibiotic-free treatments. Furthermore. this review provides clinical significance, as clinicians may seek to implement photodynamic therapy, probiotics, acetic acid, or essential oils into their own practice.

Wound pH and temperature as predictors of healing: an observational study

OBJECTIVE

The aim of this study was to measure wound pH, wound temperature and wound size together to gain further understanding of their impact as predictors of wound healing outcomes.

METHOD

This study employed a quantitative non-comparative, prospective, descriptive observational design. Participants with both acute and hard-to-heal (chronic) wounds were observed weekly for four weeks. Wound pH was measured using pH indicator strips, wound temperature was measured using an infrared camera and wound size was measured using the ruler method.

RESULTS

Most of the 97 participants (65%, n=63) were male; participant's ages ranged between 18 and 77 years (mean: 42±17.10. Most of the wounds observed were surgical 60%, (n=58) and 72% (n=70) of the wounds were classified as acute, with 28% (n=27) classified as hard-to-heal wounds. At baseline, there was no significant difference in pH between acute and hard-to-heal wounds; overall the mean pH was 8.34±0.32, mean temperature was 32.86±1.78°C) and mean wound area was 910.50±1132.30mm2. In week 4, mean pH was 7.71±1.11, mean temperature was 31.90±1.76°C and mean wound area was 339.90±511.70mm2. Over the study follow-up period, wound pH ranged from 5-9, from week 1 to week 4, mean pH reduced by 0.63 units from 8.34 to 7.71. Furthermore, there was a mean 3% reduction in wound temperature and a mean 62% reduction in wound size.

CONCLUSION

The study demonstrated that a reduction in pH and temperature was associated with increased wound healing as evidenced by a corresponding reduction in wound size. Thus, measuring pH and temperature in clinical practice may provide clinically meaningful data pertaining to wound status.

A time-dependent survival analysis for early prognosis of chronic wounds by monitoring wound alkalinity

The objective is to determine whether monitoring wound alkalinity between visits may help prognosticate chronic wound healing. The alkalinity of 167 wounds during the first 3 visits was assessed using disposable DETEC® pH. Wounds grouped by frequency of alkaline results were compared by % wound size reduction during each visit and 120-day healing probability. The Cox proportional hazards model for time-dependent variables was used to generate non-healing probability curves, where variables are binary (alkaline/non-alkaline, infection/no infection), categorical (wound type), and continuous (wound area); the response is time to complete wound healing; and the event of interest is complete wound healing in 120 days. Results show that wounds with frequent alkaline results have significantly smaller % size reduction per visit. Logistic regression shows an increase in 120-day healing probability with fewer alkaline results. Survival analysis shows that the instantaneous healing rate of non-alkaline or non-alkaline transitioning wounds is 1.785, 2.925, and 5.908 times that of alkaline or alkaline-transitioning wounds for 1, 2, and 3 alkalinity measurements, respectively. Furthermore, the concordance statistic of each survival model shows that goodness of fit increases with more alkalinity measurements. Overall, frequent wound alkalinity assessments may serve as a novel way to prognosticate wound healing outcomes.

Biofilm and wound healing: from bench to bedside

The bubbling community of microorganisms, consisting of diverse colonies encased in a self-produced protective matrix and playing an essential role in the persistence of infection and antimicrobial resistance, is often referred to as a biofilm. Although apparently indolent, the biofilm involves not only inanimate surfaces but also living tissue, making it truly ubiquitous. The mechanism of biofilm formation, its growth, and the development of resistance are ever-intriguing subjects and are yet to be completely deciphered. Although an abundance of studies in recent years has focused on the various ways to create potential anti-biofilm and antimicrobial therapeutics, a dearth of a clear standard of clinical practice remains, and therefore, there is essentially a need for translating laboratory research to novel bedside anti-biofilm strategies that can provide a better clinical outcome. Of significance, biofilm is responsible for faulty wound healing and wound chronicity. The experimental studies report the prevalence of biofilm in chronic wounds anywhere between 20 and 100%, which makes it a topic of significant concern in wound healing. The ongoing scientific endeavor to comprehensively understand the mechanism of biofilm interaction with wounds and generate standardized anti-biofilm measures which are reproducible in the clinical setting is the challenge of the hour. In this context of "more needs to be done", we aim to explore various effective and clinically meaningful methods currently available for biofilm management and how these tools can be translated into safe clinical practice.

Current scenario of traditional medicines in management of diabetic foot ulcers: A review

Diabetic foot infections and diabetic foot ulcers (DFU) cause significant suffering and are often recurring. DFU have three important pathogenic factors, namely, microangiopathy causing local tissue anoxia, neuropathy making the foot prone to injuries from trivial trauma, and local tissue hyperglycaemia favouring infection and delaying the wound healing. DFU have been the leading cause for non-traumatic amputations of part or whole of the limb. Western medicines focus mainly on euglycaemia, antimicrobials, debridement and wound cover with grafts, and off-loading techniques. Advances in euglycaemic control, foot care and footwear, systemic antimicrobial therapy, and overall health care access and delivery, have resulted in an overall decrease in amputations. However, the process of wound care after adequate debridement remains a major cost burden globally, especially in developing nations. This process revolves around two basic concerns regarding control/eradication of local infection and promotion of faster healing in a chronic DFU without recurrence. Wound modulation with various dressings and techniques are often a costly affair. Some aspects of the topical therapy with modern/Western medicines are frequently not addressed. Cost of and compliance to these therapies are important as both the wounds and their treatment are “chronic.” Naturally occurring agents/medications from traditional medicine systems have been used frequently in different cultures and nations, though without adequate clinical base/relevance. Traditional Chinese medicine involves restoring yin-yang balance, regulating the ‘chi’, and promoting local blood circulation. Traditional medicines from India have been emphasizing on ‘naturally’ available products to control wound infection and promote all the aspects of wound healing. There is one more group of chemicals which are not pharmaceutical agents but can create acidic milieu in the wound to satisfy the above-mentioned basic concerns. Various natural and plant derived products (e.g., honey, aloe vera, oils, and calendula) and maggots are also used for wound healing purposes. We believe that patients with a chronic wound are so tired physically, emotionally, and financially that they usually accept native traditional medicine which has the same cultural base, belief, and faith. Many of these products have never been tested in accordance to “evidence-based medicine.” There are usually case reports and experience-based reports about these products. Recently, there have been some trials (in vitro and in vivo) to verify the claims of usage of traditional medicines in management of DFU. Such studies show that these natural products enhance the healing process by controlling infection, stimulating granulation tissue, antimicrobial action, promoting fibroblastic activity and collagen deposition, etc. In this review, we attempt to study and analyse the available literature on results of topical traditional medicines, which are usually advocated in the management of DFU. An integrated and ‘holistic’ approach of both modern and traditional medicine may be more acceptable to the patient, cost effective, and easy to administer and monitor. This may also nevertheless lead to further improvement in quality of life and decrease in the rates of amputations for DFU.

Microenvironment-Based Diabetic Foot Ulcer Nanomedicine

Diabetic foot ulcers (DFU), one of the most serious complications of diabetes, are essentially chronic, nonhealing wounds caused by diabetic neuropathy, vascular disease, and bacterial infection. Given its pathogenesis, the DFU microenvironment is rather complicated and characterized by hyperglycemia, ischemia, hypoxia, hyperinflammation, and persistent infection. However, the current clinical therapies for DFU are dissatisfactory, which drives researchers to turn attention to advanced nanotechnology to address DFU therapeutic bottlenecks. In the last decade, a large number of multifunctional nanosystems based on the microenvironment of DFU have been developed with positive effects in DFU therapy, forming a novel concept of "DFU nanomedicine". However, a systematic overview of DFU nanomedicine is still unavailable in the literature. This review summarizes the microenvironmental characteristics of DFU, presents the main progress of wound healing, and summaries the state-of-the-art therapeutic strategies for DFU. Furthermore, the main challenges and future perspectives in this field are discussed and prospected, aiming to fuel and foster the development of DFU nanomedicines successfully.

Alginate-Chitosan Hydrogel Formulations Sustain Baculovirus Delivery and VEGFA Expression Which Promotes Angiogenesis for Wound Dressing Applications

Hydrogel wound dressings are effective in their ability to provide a wound-healing environment but are limited by their ability to promote later stages of revascularization. Here, a biosafe recombinant baculovirus expressing VEGFA tagged with EGFP is encapsulated in chitosan-coated alginate hydrogels using ionic cross-linking. The VEGFA, delivered by the baculovirus, significantly improves cell migration and angiogenesis to assist with the wound-healing process and revascularization. Moreover, the hydrogels have an encapsulation efficiency of 99.9%, no cytotoxicity, antimicrobial properties, good blood compatibility, promote hemostasis, and enable sustained delivery of baculoviruses over eight days. These hydrogels sustain baculovirus delivery and may have clinical implications in wound dressings or future gene therapy applications.

A wound alkalinity measurement to predict non-healing wound outcomes

Objective:

As wound pH could influence wound healing rates, this study examined the alkalinity of the entire wound during patients' follow-up visits to predict the final non-healing outcome.

Method:

Wound alkalinity of patients with diabetic foot ulcers (DFUs), venous leg ulcers, and other wounds during three follow-up visits within a four week period was recorded. All wounds were followed until 12 weeks to confirm that healed wounds did not relapse. The alkalinity of various wounds over multiple visits with varying durations was compared with final wound status to assess whether one-time wound alkalinity measurement could predict non-healing wounds. The effect of wound types, infection, age and sex on such determinations was also studied.

Results:

A total of 96 patients were included in this study. Based on probability variations of pre- and post-test non-healing outcomes from multiple visits over 12 weeks, second visit assessment gave the highest increase in risk of non-healing for an alkaline test result (+8.0%) and decrease in risk of non-healing for a non-alkaline test result (–19.7%). Moreover, a second visit (7–21 days from first visit) showed a greater change in risk for non-healing based on alkaline and non-alkaline test results (+15.7% and –38.1% respectively), compared with a visit within seven days (+6.3% and –12.5%, respectively). Wound type, infection, age and sex did not affect the prognostic ability of wound alkalinity.

Conclusion:

The results of this study support that a single wound alkalinity measurement during the second visit (7–21 days from first visit) can be used to predict non-healing wounds. Wound alkalinity may be routinely assessed to predict non-healing wounds and to determine whether the wounds are healing as expected following initial treatment.

Zein-polycaprolactone core-shell nanofibers for wound healing

In a previous study, we developed electrospun antimicrobial microfiber scaffolds for wound healing composed of a core of zein protein and a shell containing polyethylene oxide. While providing a promising platform for composite nanofiber design, the scaffolds showed low tensile strengths, insufficient water stability, as well as burst release of the antimicrobial drug tetracycline hydrochloride, properties which are not ideal for the use of the scaffolds as wound dressings. Therefore, the aim of the present study was to develop fibers with enhanced mechanical strength and water stability, also displaying sustained release of tetracycline hydrochloride. Zein was chosen as core material, while the shell was formed by the hydrophobic polymer polycaprolactone, either alone or in combination with polyethylene oxide. As compared to control fibers of pristine polycaprolactone, the zein-polycaprolactone fibers exhibited a reduced diameter and hydrophobicity, which is beneficial for cell attachment and wound closure. Such fibers also demonstrated sustained release of tetracycline hydrochloride, as well as water stability, ductility, high mechanical strength and fibroblast attachment, hence representing a step towards the development of biodegradable wound dressings with prolonged drug release, which can be left on the wound for a longer time.

Acetic Acid Use in Chronic Wound Healing: A Multiple Case Series

BACKGROUND

Acetic acid is bacteriostatic or bactericidal to many gram-negative and gram-positive microorganisms, especially Pseudomonas. Nevertheless, it has also been found to possess cytotoxic effects in concentrations as low as 0.25% inhibiting the epithelialization process during wound healing.

CASES

In this multiple case series, we present 2 cases of chronic traumatic leg wounds treated with gauze moistened with acetic acid (0.25%), which were covered with a securing dressing and compression stockinet. Both patients were told to apply gauze moistened with acetic acid (0.25%) twice daily. In both cases, the wound progressed to blue-green drainage and wet yellow slough tissue to near-complete beefy granulation tissue. At this point, acetic acid was replaced with collagen or petrolatum dressing until complete wound closure was achieved. The treatment of these wounds illustrated successful use of acetic acid for chronic wound care.

CONCLUSION

Our experience with these cases suggests that appearance of blue-green wound drainage and wet yellow slough tissue is a reasonable indication for the use of gauze moistened with acetic acid (0.25%). Further research is needed to test the efficacy of these principles in guiding acetic acid use in wound care.

Ray Amputation in a Traumatic Diabetic Foot

Diabetic foot is a complex syndrome that is co-morbid with other diabetic complications such as peripheral arterial disease (PAD) and peripheral neuropathy. Patients with the diabetic foot are increasingly prone to diabetic foot ulcers (DFUs) due to a high infection susceptibility and poor wound healing possibly prompting the need for minor or major amputations. We herein highlight the case of a 47-year-old male with a traumatic diabetic foot who necessitated a Ray amputation (RA). The notable aspects of this case are the late presentation of a patient with uncontrolled diabetes who could have avoided this complication if he went to seek help earlier and how diabetic foot is controlled and managed in a low-income resource setting. This case also highlights how physicians can better diagnose and treat diabetic foot complications with a scoring metric.

Prevention and treatment of burn wound infections: the role of topical antimicrobials

INTRODUCTION

Infections related to the skin are the principal drivers of morbidity and mortality following severe burn, therefore a diverse armamentarium of topical antimicrobial agents were developed over the history of burn care. The last 30 years witnessed dramatic changes in the application of surgical intervention and utilization of topical therapies.

AREAS COVERED

We explore well-known topical antimicrobial products used in burn care. First, we investigate how fundamental changes in the practice of burn surgery influenced the choice of topical therapies used. Then, we examine antimicrobial creams and ointments commonly recognized due to their long record of use in burn care. Next, we dive into antimicrobial solutions commonly used as adjuncts to surgical intervention. Finally, we explore representative antimicrobial dressings, an ever-advancing roster of products opening the door to the next era in burn care. We also describe how these new agents relate to already established tools in present-day burn care.

EXPERT OPINION

In the current day, though the wisdom of early excision and wound closure remains valid, we continue to strive to minimize aggressive wound excision and disfiguring donor tissue collection while securing rapid wound closure. To this end, antimicrobial therapies are titrated to optimize operative outcomes and provide non-operative wound care when appropriate. Antimicrobial agents bridge the gap with the next generation of skin substitute and skin replacement therapies.

The impact of topical agents and dressing on pH and temperature on wound healing: A systematic, narrative review

To assess the impact of topical agents and dressings on surface wound pH, temperature, and subsequent wound healing. This was a systematic, narrative review of the literature, following the PRISMA (2020) guidelines. The databases searched were Medline PubMed, Cumulative Index to Nursing and Allied Health Literature (CINAHL), Cochrane Library, Embase, Web of Science, and Scopus. Data synthesis and analysis were conducted using a structured narrative synthesis. The quality of the included clinical studies was appraised using the Evidence-Based Literature (EBL) Critical Appraisal Tool. A total of six clinical studies were assessed as eligible for inclusion, A total of six dressings/topical agents were assessed and the types of wounds included non-healing chronic wounds. Of the studies, five explored pH and one explored temperature. The EBL validity of the clinical studies was low (mean quality score was 51.3%). The five clinical studies that explored pH investigated different dressings and topical agents reporting an associated reduction in pH and improved wound outcomes. One clinical study investigated the impact of topical sodium nitrite on temperature and found that sodium nitrite increased peri-wound skin temperature and improved wound outcomes with a reduction in leg ulcer size. Given the low certainty of the evidence, we cannot confidently recommend the use of any particular topical agent or dressing to manipulate pH, or temperature to improve wound outcomes. Thus, there is a need for further research to develop a greater understanding of this topic. Irish Research Council, Enterprise Partnership Scheme.

Role of an acidic environment in the treatment of diabetic foot infections: A review

Management of diabetic foot ulcers is the biggest challenge to the clinician, as conventional antibiotic therapies and local wound care have their own limitations. They are not effective for control of infections and promotion of healing because of cytotoxic effects. In view of cytotoxicity of routinely used topical antiseptic agents, this article focuses on the search of an ideal topical antiseptic agent that is safe and effective in controlling infectious agents and also in promoting the healing process. This review focuses on the use of various acids such as citric, acetic, hyaluronic, and hypochlorous acids as topical agents in diabetic foot infections. This article also focuses on the different roles of acids in the treatment of diabetic foot infections.

Acetic acid and the skin: a review of vinegar in dermatology

Vinegar is commonly used as a home remedy for many skin problems. It is important for dermatologists to understand the evidence supporting its use in skin disease, as well as potential adverse effects, so they can properly counsel patients on the safe use of this widely available treatment. Vinegar possesses antimicrobial and antioxidant properties that provide utility in wound care as well as bacterial and fungal infections. There is also evidence to support its use in pruritus, head lice removal, and treatment of striae gravidarum. While generally safe, inappropriate use can result in damage to the skin. In this review, we discuss the evidence supporting vinegar as a treatment for skin disease, as well as adverse events reported from misuse, to provide dermatologists the knowledge to counsel patients on the safe and appropriate use of vinegar.

The role of acetic acid in orthopaedic surgery

Acetic acid has become more commonly used in orthopaedic surgery. The purposed roles include biofilm eradication and surgical debridement, postoperative scar reduction and managing soft tissue injuries. Current research is scarce and does not provide conclusive evidence behind acetic acid’s efficacy in orthopaedic procedures such as biofilm eradication or acetic acid iontophoresis in soft tissue injuries. Current literature on acetic acid’s effects on biofilm eradication is composed of in-vitro studies, which do not demonstrate the potential clinical efficacy of acetic acid. Acetic acid iontophoresis is a novel technique which is now more commonly accepted for soft tissues injuries. Our literature search identified calcifying tendonitis of the shoulder, rotator cuff tendinopathy, heel pain syndrome, plantar fasciitis, achilles tendonitis, calcifying tendonitis of the ankle, myositis ossificans and cervical spondylosis as documented clinical uses. In this narrative review, we present the current uses of acetic acid and acetic acid iontophoresis, while evaluating the evidence revolving around its efficacy, benefits and risks.

A novel method for treatment of pseudomonas pyogenic hepatic abscess complicating an echinococcal cyst by irrigation with acetic acid. A case report and literature review

Hepatic hydatid cysts can be complicated by pyogenic abscesses. We report a case of hepatic hydatid cysts presenting to Sultan Qaboos University Hospital (SQUH) on 29 June 2010 complicated by secondary infection with fully sensitive Pseudomonas aeruginosa. The infection persisted despite standard treatment (drainage and systemic antibiotics) and was eventually cured with a novel method using acetic acid.

Methods

Instillation of acetic acid (in the form of white vinegar) into the hepatic abscess through the pig tail drainage tube.

Results

The administration of acetic acid (6%) in the form of white vinegar was well tolerated and safe to the patient and resulted in complete clinical and radiographic resolution of the hepatic abscess.

Conclusion

Acetic acid (vinegar) irrigation can be used to clear a refractory pyogenic hepatic abscess due toP aeruginosa infection.

Optimization of psoriasis mouse models

INTRODUCTION

Psoriasis, is a common, chronic, autoimmune, inflammatory, relapsing disease, which would benefit from reliable and human-relevant animal models to test drugs pre-clinically and to understand their mechanism of action. Because of its ease of use, convenience and low cost, the imiquimod (IMQ)-induced psoriasis-like model is widely utilized; however, it is not known whether all mouse strains are equivalent and if the hairless mouse is appropriate, so that the imiquimod model can be further optimized.

METHODS

Under similar experimental conditions, common mouse strains (BALB/c, C57BL/6J, and ApoE) and a new hairless strain (ApoE/SKH-hr2) as well as several inducers (IMQ, IMQ + acetic acid (AcOH) topical and IMQ + AcOH systemic) were compared by clinical, histopathological, biophysical and locomotor activity assessments.

RESULTS AND DISCUSSION

The BALB/c mice yielded an optimal psoriasis-like phenotype with IMQ + AcOH topical treatment, and the corresponding phenotypes for the other mouse strains were C57BL/6J moderate and ApoE mild. In contrast, the ApoE/SKH-hr2 mice, as a result of the absence of a Munro abscess in the histopathology analysis, left doubt about the psoriasis-like acquisition. Locomotor activity of BALB/c mice treated with IMQ, IMQ + AcOH topically and IMQ + AcOH systemically showed decreased distance and rearing coverage and increased immobility with all treatments. Hence, the BALB/c mouse strain appears to be an optimal psoriasis-like model when utilizing IMQ + AcOH topical application.

Antibiofilm and antipersister activity of acetic acid against extensively drug resistant Pseudomonas aeruginosa PAW1

Pseudomonas aeruginosa is an ESKAPE pathogen associated with difficult-to-treat burn wound and surgical-site infections. This study aimed to characterise an extensively drug resistant (XDR) P. aeruginosa isolate (designated PAW1) and to investigate the antibiofilm and antipersister effect of acetic acid on PAW1. PAW1 was identified using biotypic (VITEK) and genotypic (16S rDNA) analysis. Minimum inhibitory concentration (MIC) and disc susceptibility testing showed high level resistance against all antibiotics from classes including beta lactams, cephems, carbapenems and fluoroquinolones. It was therefore identified as extensively drug resistant (XDR), showing resistance to all antibiotics except for, aminoglycoside (gentamicin and netilmicin) and lipopeptides (polymyxin B). Time kill assays showed antibiotic tolerant, persister cell formation in presence of 100X MICs of gentamicin and polymyxin B. Other virulence traits such as ability to produce lipase, protease, haemolysin, and siderophores and to form biofilms were additional factors which may contribute to its pathogenicity. PAW1 showed promising susceptibility against acetic acid with MIC and minimum biofilm inhibitory concentration of 0.156% (v/v). Percent viability of PAW1 was dependent on dose and treatment time of acetic acid. 0.625% acetic acid treatment of 5 minutes was effective in killing >90% planktonic cells showing lesser toxicity to L929 cells (IC₅₀ = 0.625%). Biofilm disruption caused due to acetic acid was also dose dependent, showing 40.57% disruption after treatment with 0.625% acetic acid for 5 minutes. FESEM imaging and live dead staining of planktonic and biofilm forms of PAW1 confirmed that acetic acid treatment caused 19.04% of cell shrinkage and disruption of extracellular matrix resulting in killing of cells. Antipersister activity of acetic acid was demonstrated by showing complete killing of PAW1 at 4X MIC. Overall, this study characterised an XDR isolate P. aeruginosa showing resistance and tolerance to various antibiotics. Antipersister and antibiofilm effect of acetic acid demonstrates the importance of forgotten topical agents as an effective strategy to treat XDR pathogens.

Efficacy of diluted vinegar in treating granular myringitis: a randomised controlled trial

OBJECTIVE

This study aimed to evaluate the outcome of granular myringitis treatment of 1 per cent diluted vinegar ear drops or 1 per cent chloramphenicol ear drops and to assess the side effects of 1 per cent diluted vinegar.

METHOD

Twenty-four patients aged over 18 years and diagnosed with granular myringitis grade I or II within 90 days of symptom onset were included. Patients were equally randomised into either the 1 per cent diluted vinegar group or the 1 per cent chloramphenicol group. Outcome of treatment and side effects were compared between groups. The main outcome measure was completely epithelialised tympanic membrane at the eight-week period.

RESULTS

Eleven of 12 patients treated with 1 per cent diluted vinegar had complete recovery. In the 1 per cent chloramphenicol group, 8 of 12 patients recovered. The difference between groups was not statistically significant (p = 0.156). The observed side effects of diluted vinegar included dizziness and mild external auditory canal irritation.

CONCLUSION

One per cent diluted vinegar is an interesting option for granular myringitis. Other comparative advantages of 1 per cent diluted vinegar include its low price and no induction of antimicrobial resistance.

Use of Negative-Pressure Wound Therapy With Instillation and Dwell in Breast Reconstruction

SUMMARY

The use of negative-pressure wound therapy (NPWT) has expanded over the last 3 decades, paralleled and documented by an increase in research. This article discusses the evolution and current applications of NPWT in modern breast reconstruction. Negative-pressure wound therapy with instillation and dwell (NPWTi-d) technology can be used to remove infectious material, facilitate salvaging compromised tissue, and stabilize the soft-tissue environment. Published consensus NPWTi-d guidelines can aid in treatment selection and implementation of this new technology. The therapeutic approach of simultaneously removing infectious material and actively improving mastectomy flap perfusion and thickness is a burgeoning concept, and illustrative cases are presented. NPWTi-d preliminary use has led to reconstruction salvage with reproducible early experience and outcomes, and it is hoped that it will raise interest and awareness of this promising application of the technology to improve breast reconstruction outcomes.

Evolution of surgical modalities in the management of rhinophyma: our experience

Rhinophyma is a progressive disease of the nose, which is characterised by skin thickening and sebaceous hyperplasia. Patients with rhinophyma are often stigmatised due to worsening disfigurement of their nose. This can also result in functional impairment such as reduced nasal patency. Severe cases of rhinophyma are best managed with varied surgical interventions, as there is no clear 'gold standard' treatment that has been described. We present our experiences in the management of rhinophyma and the evolution of treatment modalities that have been employed over a nine-year period.

A Device to Predict Short-Term Healing Outcome of Chronic Wounds

Objective: While myriads of studies have suggested that a survey of wound pH environment could indicate wound healing activities, it is not clear whether wound alkalinity can be used as a prognostic indicator of nonhealing wounds. Currently available systems cannot reliably assess the pH environment across wounds, which is the objective of this study. Approach: A disposable device, DETEC® pH, was developed and characterized on its ability to map wound alkalinity by pressing a freshly recovered wound dressing against its test surface. By comparing the wound's alkalinity and size reduction rates (∼7 days) following pH measurement, we assessed the capability of wound alkalinity to prognosticate subsequent short-term wound size reduction rates. Results: The device had high accuracy and specificity in determining the alkalinity of simulated wound fluids soaked onto wound dressing. The type of wound dressing type had an insignificant effect on its detection sensitivity. Upon testing discarded wound dressings from human patients, the device quickly determined alkaline and acidic wounds. Finally, statistical analyses of wound size reduction rates in wounds with various alkalinities confirmed that wound alkalinity has a strong influence on, at least, short-term wound healing activity. Innovation: Without directly contacting the patient, this device provides a quick assessment of wound alkalinity to prognosticate immediate and short-term wound healing activities. Conclusion: DETEC® pH may serve as a prognosis device for wound care specialists during routine wound assessment to predict wound healing progress. This information can assist the decision-making process in a clinical setting and augur well for chronic wound treatment. DETEC® pH can also be used as an aid for home health care nurses or health care providers to screen nonhealing wounds outside clinics.

N-Acetyl-cysteine and Mechanisms Involved in Resolution of Chronic Wound Biofilm

Chronic wounds are a major global health problem with the presence of biofilm significantly contributing to wound chronicity. Current treatments are ineffective in resolving biofilm and simultaneously killing the bacteria; therefore, effective biofilm-resolving drugs are needed. We have previously shown that, together with α-tocopherol, N-acetyl-cysteine (NAC) significantly improves the healing of biofilm-containing chronic wounds, in a diabetic mouse model we developed, by causing disappearance of the bacteria and breakdown of the extracellular polymeric substance (EPS). We hypothesize that NAC creates a microenvironment that affects bacterial survival and EPS integrity. To test this hypothesis, we developed an in vitro biofilm system using microbiome taken directly from diabetic mouse chronic wounds. For these studies, we chose mice in which chronic wound microbiome was rich in Pseudomonas aeruginosa (97%). We show that NAC at concentrations with pH < pKa causes bacterial cell death and breakdown of EPS. When used before biofilm is formed, NAC leads to bacterial cell death whereas treatment after the biofilm is established NAC causes biofilm dismantling accompanied by bacterial cell death. Mechanistically, we show that NAC can penetrate the bacterial membrane, increase oxidative stress, and halt protein synthesis. We also show that low pH is important for the actions of NAC and that bacterial death occurs independently of the presence of biofilm. In addition, we show that both the acetyl and carboxylic groups play key roles in NAC functions. The results presented here provide insight into the mechanisms by which NAC dismantles biofilm and how it could be used to treat chronic wounds after debridement (NAC applied at the start of culture) or without debridement (NAC applied when biofilm is already formed). This approach can be taken to develop biofilm from microbiome taken directly from human chronic wounds to test molecules that could be effective for the treatment of specific biofilm compositions.

Challenges and opportunities of pH in chronic wounds

Regarded as a silent epidemic, chronic wounds are a global public health issue. Wound healing is a complex, synchronized cascade of physiological processes restoring the anatomic and functional integrity of the skin; however, chronic wounds fail to proceed through the wound healing cascade. Wound pH oscillates during wound healing, usually traversing from a neutral pH to an acidic pH, while chronic wounds perpetuate in an elevated alkaline milieu. Although a neglected clinical parameter, pH has implications for relatively all pathologies of wound healing affecting oxygen release, angiogenesis, protease activity, bacterial toxicity and antimicrobial activity. Despite the array of wound healing products currently marketed, understanding the implications of pH on arresting wound healing can stimulate innovation within this vast market.

A pilot study of the in vitro antimicrobial activity and in vivo residual activity of chlorhexidine and acetic acid/boric acid impregnated cleansing wipes

BACKGROUND

Topical antimicrobials are recommended for first line treatment of surface and superficial infections in dogs. This is especially important given the increasing prevalence of antimicrobial resistant infections. Antimicrobial wipes have become popular, but there are a lack of controlled studies assessing their in vitro antimicrobial and in vivo residual activity. We aimed to assess the antimicrobial efficacy of two commercial antimicrobial wipes against frequently isolated pathogens. Ten clinical and one reference isolate each of meticillin-susceptible Staphylococcus pseudintermedius (MSSP), meticillin-resistant S. pseudintermedius (MRSP), Escherichia coli (EC), extended spectrum beta-lactamase (ESBL) producing E. coli (ESBL-EC), Pseudomonas aeruginosa (PA) and Malassezia pachydermatis (MP) were tested using a modified Kirby-Bauer technique. Each isolate was tested against 6 mm discs of chlorhexidine (CHX) and acetic acid/boric acid (AABA) wipes, and positive and negative controls either overnight (bacteria) or for 3 days (Malassezia). Healthy dogs were treated with the wipes and distilled water on a randomised flank (n = 5 each). Hair samples (1 cm; 0.1 g) taken at days 0, 1 and 3 were inoculated with an isolate of each organism. Zones of inhibition (ZI) were measured.

RESULTS

All isolates produced confluent growth with AABA and control wipes, except for the cleansing wipes and MP (median ZI 12 mm; 95% CI 8.2-15.8). The median (95% CI) CHX wipe ZIs (mm) were: MP 48.0 (47.0-49.0), MSSP 15.6 (14.2-17.0), MRSP 14.0 (13.6-14.4), EC 13.6 (12.0-15.2) and ESBL-EC 10.0 (9.4-10.6). PA showed confluent growth. The differences between the bacterial isolates was significant (Kruskal-Wallis p < 0.0001; post-tests MSSP = MRSP = EC > EBSL-EC > PA). Confluent growth was visible with all the hair samples.

CONCLUSION

CHX but not AABA showed in vitro efficacy against MSSP, MRSP, EC and MP. ESBL-EC were less susceptible and there was no activity against PA. There was no residual activity on hair. Additional studies are required to determine efficacy of these products in clinically affected patients.

Recent Advances in Non-Conventional Antimicrobial Approaches for Chronic Wound Biofilms: Have We Found the 'Chink in the Armor'?

Chronic wounds are a major healthcare burden, with huge public health and economic impact. Microbial infections are the single most important cause of chronic, non-healing wounds. Chronic wound infections typically form biofilms, which are notoriously recalcitrant to conventional antibiotics. This prompts the need for alternative or adjunct ‘anti-biofilm’ approaches, notably those that account for the unique chronic wound biofilm microenvironment. In this review, we discuss the recent advances in non-conventional antimicrobial approaches for chronic wound biofilms, looking beyond standard antibiotic therapies. These non-conventional strategies are discussed under three groups. The first group focuses on treatment approaches that directly kill or inhibit microbes in chronic wound biofilms, using mechanisms or delivery strategies distinct from antibiotics. The second group discusses antimicrobial approaches that modify the biological, chemical or biophysical parameters in the chronic wound microenvironment, which in turn enables the disruption and removal of biofilms. Finally, therapeutic approaches that affect both, biofilm bacteria and microenvironment factors, are discussed. Understanding the advantages and limitations of these recent approaches, their stage of development and role in biofilm management, could lead to new treatment paradigms for chronic wound infections. Towards this end, we discuss the possibility that non-conventional antimicrobial therapeutics and targets could expose the ‘chink in the armor’ of chronic wound biofilms, thereby providing much-needed alternative or adjunct strategies for wound infection management.

Synergistic Impacts of Organic Acids and pH on Growth of Pseudomonas aeruginosa: A Comparison of Parametric and Bayesian Non-parametric Methods to Model Growth

Different weak organic acids have significant potential as topical treatments for wounds infected by opportunistic pathogens that are recalcitrant to standard treatments. These acids have long been used as bacteriostatic compounds in the food industry, and in some cases are already being used in the clinic. The effects of different organic acids vary with pH, concentration, and the specific organic acid used, but no studies to date on any opportunistic pathogens have examined the detailed interactions between these key variables in a controlled and systematic way. We have therefore comprehensively evaluated the effects of several different weak organic acids on growth of the opportunistic pathogen Pseudomonas aeruginosa. We used a semi-automated plate reader to generate growth profiles for two different strains (model laboratory strain PAO1 and clinical isolate PA1054 from a hospital burns unit) in a range of organic acids at different concentrations and pH, with a high level of replication for a total of 162,960 data points. We then compared two different modeling approaches for the interpretation of this time-resolved dataset: parametric logistic regression (with or without a component to include lag phase) vs. non-parametric Gaussian process (GP) regression. Because GP makes no prior assumptions about the nature of the growth, this method proved to be superior in cases where growth did not follow a standard sigmoid functional form, as is common when bacteria grow under stress. Acetic, propionic and butyric acids were all more detrimental to growth than the other acids tested, and although PA1054 grew better than PAO1 under non-stress conditions, this difference largely disappeared as the levels of stress increased. As expected from knowledge of how organic acids behave, their effect was significantly enhanced in combination with low pH, with this interaction being greatest in the case of propionic acid. Our approach lends itself to the characterization of combinatorial interactions between stressors, especially in cases where their impacts on growth render logistic growth models unsuitable.