Treating diabetic foot ulcers with antimicrobial wound dressing impregnated with dialkylcarbamoyl chloride

OBJECTIVE

Diabetic foot ulcers (DFUs) are at significant risk of becoming infected, with an associated elevated risk of amputation. Choosing an appropriate treatment would help prevent infection, improve healing and patients' quality of life, as well as reduce healthcare costs. The aim of this study was to assess the efficacy of a dialkylcarbamoyl chloride (DACC)-coated wound dressing to reduce bacterial load in the treatment of infected diabetic foot ulcers with signs of biofilm.

METHOD

In this prospective, descriptive observational study, patients with infected DFUs were treated with a DACC-coated wound dressing, and were followed until complete healing was achieved. Levels of bacterial load and the presence of biofilm were also assessed.

RESULTS

The patients consisted of 42 males and 19 females, with a mean age of 54.4 years. All wounds exhibited complete wound closure upon treatment with the DACC-coated wound dressing, with an average time to heal of 71.8 days. A total of 53 patients had received systemic antibiotic treatment prior to study enrolment, and the number of patients requiring antibiotic treatment reduced to 20 during the study. The level of bacterial load (including biofilm) was reduced, leading to wound progression in a proportion of wounds.

CONCLUSION

The findings of this study revealed that treatment with a non-medicated antimicrobial wound dressing was an appropriate dressing choice to reduce microbial load and aid promotion of healing in infected DFUs with the presence of biofilm.

Efficacy of Dialkylcarbamoylchloride (DACC)-Impregnated Dressings in Surgical Wound Management: A Review

Surgical site infections (SSIs) are a significant challenge in postoperative care, leading to increased morbidity, extended hospital stays, and elevated healthcare costs. Traditional antimicrobial dressings, such as those containing silver or iodine, have limitations, including cytotoxicity and the potential for antimicrobial resistance. Dialkylcarbamoyl chloride (DACC)-impregnated dressings offer a novel approach, employing a physical mechanism to bind and remove bacteria without the use of chemical agents, thereby reducing the risk of resistance. This review summarizes current evidence on the efficacy of DACC dressings in preventing SSIs and promoting wound healing. Findings from multiple studies indicate that DACC dressings reduce bacterial burden and SSI rates across various surgical procedures, including cesarean sections and vascular surgeries. Additionally, DACC dressings demonstrate potential in managing hard-to-heal wounds, such as diabetic foot ulcers, by reducing bacterial load and biofilm formation. Furthermore, they present advantages in antimicrobial stewardship and cost-effectiveness by minimizing the need for antibiotics and decreasing overall healthcare expenses. However, the current literature is limited by small sample sizes, methodological weaknesses, heterogeneity in study designs, and a lack of long-term data. Future research should focus on high-quality randomized controlled trials across diverse surgical populations, comprehensive cost-effectiveness analyses, and long-term outcomes to establish the full clinical impact of DACC dressings. With further validation, DACC-impregnated dressings could become a critical tool in sustainable postoperative wound care.

In vitro and in vivo evaluation of the antimicrobial effectiveness of non-medicated hydrophobic wound dressings

There is an increasing use of non-medicated wound dressing with claims of irreversible bacterial binding. Most of the data are from in vitro models which lack clinical relevance. This study employed a range of in vitro experiments to address this gap and we complemented our experimental designs with in vivo observations using dressings obtained from patients with diabetes-related foot ulcers. A hydrophobic wound dressing was compared with a control silicone dressing in vitro. Test dressings were placed on top of a Pseudomonas aeruginosa challenge suspension with increasing concentrations of suspension inoculum in addition to supplementation with phosphate buffered saline (PBS) or increased protein content (IPC). Next, we used the challenge suspensions obtained at the end of the first experiment, where bacterial loads from the suspensions were enumerated following test dressing exposure. Further, the time-dependent bacterial attachment was investigated over 1 and 24 h. Lastly, test dressings were exposed to a challenge suspension with IPC, with or without the addition of the bacteriostatic agent Deferiprone to assess the impacts of limiting bacterial growth in the experimental design. Lastly, two different wound dressings with claims of bacterial binding were obtained from patients with chronic diabetes-related foot ulcers after 72 h of application and observed using scanning electron microscope (SEM). Bacteria were enumerated from each dressing after a 1-h exposure time. There was no statistical difference in bacterial attachment between both test dressings when using different suspension inoculum concentrations or test mediums. Bacterial attachment to the two test dressings was significantly lower (p < 0.0001) when IPC was used instead of PBS. In the challenge suspension with PBS, only the hydrophobic dressing achieved a statistically significant reduction in bacterial loads (0.5 ± 0.05 log colony forming units; p = 0.001). In the presence of IPC, there was no significant reduction in bacterial loads for either test dressing. When bacterial growth was arrested, attachment to the test dressings did not increase over time, suggesting that the number of bacteria on the test dressings increases over time due to bacterial growth. SEM identified widespread adsorption of host fouling across the test dressings which occurred prior to microbial binding. Therein, microbial attachment occurred predominantly to host fouling and not directly to the dressings. Bacterial binding is not unique to dialkylcarbamoyl chloride (DACC) dressings and under clinically relevant in vitro conditions and in vivo observations, we demonstrate (in addition to previously published work) that the bacterial binding capabilities are not effective at reducing the number of bacteria in laboratory models or human wounds.

Experimental and clinical evidence for DACC-coated dressings: an update

OBJECTIVE

To update the evidence in relation to the use of dialkylcarbamoyl chloride (DACC)-coated wound dressings in the prevention, treatment and management of wounds.

METHOD

PubMed and PubMed Central databases were searched to identify articles published since 2020 describing the experimental and clinical evidence for DACC-coated dressings, and their antimicrobial effect, as well as their impact on the prevention and treatment of infected wounds. The identified articles were then narratively reviewed.

RESULTS

The search yielded 113 articles (plus references from ad hoc sources), of which nine met the inclusion criteria. Of the nine included studies, five related to clinical aspects and four were laboratory studies.

CONCLUSION

A number of new studies have provided further evidence for the mode of action of the antimicrobial effect of DACC-coated dressings and its wide spectrum effect (including World Health Organization-prioritised microorganisms). Additional clinical studies have provided evidence of new applications, such as in treating wounds in paediatric patients, and extended the evidence relating to their use in treating surgical site infections. Evidence also shows that DACC-coated wound dressings can aid in the binding of biofilms, and how this technology can align and support antimicrobial stewardship in the prevention of antimicrobial resistance.

Buruli-RifDACC: Evaluation of the efficacy and cost-effectiveness of high-dose versus standard-dose rifampicin on outcomes in Mycobacteriumulcerans disease, a protocol for a randomised controlled trial in Ghana

Background

Buruli ulcer (BU) can lead to disfiguring ulcers and permanent disability. The 2030 World Health Organization (WHO) road map for Neglected Tropical Diseases (NTDs) calls for major scaling up in diagnosis and management to eliminate disability due to the disease. Current treatment for BU is with daily oral rifampicin (10mg/kg dose) and clarithromycin (15mg/kg dose) for eight weeks, combined with standard gauze wound dressings. Dialkylcarbamoyl chloride (DACC)-coated dressings have been shown to irreversibly bind bacteria on wound surfaces resulting in their removal when dressings are changed. This trial aims to determine whether combining a high-dose oral rifampicin regimen with DACC dressings can improve the rate of wound healing relative to standard-dose oral rifampicin combined with DACC dressings.

Methods

This is an individual, multi-centre Phase 3 randomised controlled trial, which will be conducted in three clinical sites in Ghana. The primary outcome measure will be the mean time to clearance of viable mycobacteria. Cost and health-related quality of life data will be collected, and a cost-effectiveness analysis will be performed.

Discussion

The findings from this trial could lead to a change in how BU is treated. A shorter but more efficacious regimen would lead to improved treatment outcomes and potentially substantial financial and economic savings.

Trial registration

Pan African Clinical Trials Repository (registration number; PACTR202011867644311). Registered on 30 th November 2020.

In vivo observations of biofilm adhering to a dialkylcarbamoyl chloride-coated mesh dressing when applied to diabetes-related foot ulcers: A proof of concept study

In this proof-of-concept study of twenty participants, we sought to determine if a DACC (Dialkylcarbamoyl chloride)-coated mesh dressing demonstrates an ability to adhere biofilm when placed on Diabetes Related Foot Ulcers (DRFUs) with chronic infection. The study also sought to determine if removal of the DACC-coated mesh dressings contributes to reducing the total number of bacteria in DRFUs, by exploring the total microbial loads, microbial community composition, and diversity. Standard of care was provided in addition to the application of DACC or DACC hydrogel every three days for a total of two weeks. Wound swabs, tissue curettage, and soiled dressings were collected pre and post-treatment. Tissue specimens obtained pre-treatment were analysed with scanning electron microscopy (SEM) and peptide nucleic acid fluorescent in situ hybridisation (PNA-FISH) with confocal laser scanning microscopy and confirmed the presence of biofilm in all DRFUs. SEM confirmed the presence of biofilms readily adhered to soiled DACC-coated mesh dressings pre- and post-treatment in all participants. Real-time quantitative polymerase chain reaction (qPCR) demonstrated the mean total microbial load of DRFUs in 20 participants did not change after two weeks of therapy (pre-treatment = 4.31 Log10 16 S copies (±0.8) versus end of treatment = 4.32 Log10 16 S copies (±0.9), P = .96, 95% CI -0.56 to 0.5). 16 S sequencing has shown the microbial composition of DACC dressings and wound swabs pre- and post-treatment remained similar (DACC; R = -.047, P = .98, Swab; R = -.04, P = .86), indicating the microbial communities originate from the ulcer. Biofilms adhere to DACC-coated mesh dressings; however, this may not reduce the total microbial load present within DRFU tissue. Wound dressings for use in hard-to-heal wounds should be used as an adjunct to a good standard of care which includes debridement and wound bed preparation.

Buruli-RifDACC: Evaluation of the efficacy and cost-effectiveness of high-dose versus standard-dose rifampicin on outcomes in Mycobacterium ulcerans disease, a protocol for a randomised controlled trial in Ghana [version 1; peer review: 2 approved]

Background

Buruli ulcer (BU) can lead to disfiguring ulcers and permanent disability. The 2030 World Health Organization (WHO) road map for Neglected Tropical Diseases (NTDs) calls for major scaling up in diagnosis and management to eliminate disability due to the disease. Current treatment for BU is with daily oral rifampicin (10mg/kg dose) and clarithromycin (15mg/kg dose) for eight weeks, combined with standard gauze wound dressings. Dialkylcarbamoyl chloride (DACC)-coated dressings have been shown to irreversibly bind bacteria on wound surfaces resulting in their removal when dressings are changed.  This trial aims to determine whether combining a high-dose oral rifampicin regimen with DACC dressings can improve the rate of wound healing relative to standard-dose oral rifampicin combined with DACC dressings.

Methods

This is an individual, multi-centre Phase 3 randomised controlled trial, which will be conducted in three clinical sites in Ghana. The primary outcome measure will be the mean time to clearance of viable mycobacteria. Cost and health-related quality of life data will be collected, and a cost-effectiveness analysis will be performed.

Discussion

The findings from this trial could lead to a change in how BU is treated. A shorter but more efficacious regimen would lead to improved treatment outcomes and potentially substantial financial and economic savings.

Modified aluminosilicates display antibacterial activity against nontuberculous mycobacteria and adsorb mycolactone and Mycobacterium ulcerans in vitro

Mycobacterium ulcerans (MU) infection of skin and soft tissue leads to chronic skin ulceration known as Buruli ulcer. MU releases a lipid-like toxin, mycolactone, that diffuses into the tissue, effecting disease through localized tissue necrosis and immunosuppression. Cutaneous Buruli ulcer wounds slowly advance from a painless pre-ulcerative stage to an ulcerative lesion, leading to disparities in the timing of medical intervention and treatment outcomes. Novel Buruli ulcer wound management solutions could complement and supplement systemically administered antimicrobials and reduce time to healing. Capitalizing on nanopore structure, adsorption, and exchange capacities, aluminosilicate nanozeolites (nZeos) and geopolymers (GPs) were developed and investigated in the context of therapeutics for mycobacterial disease ulcerative wound care. nZeos were ion exchanged with copper or silver to assess the antimicrobial activity against MU and Mycobacterium marinum, a rapid growing, genetic ancestor of MU that also causes skin and soft tissue infections. Silver- and copper-exchanged nZeos were bactericidal against MU, while only silver-exchanged nZeos killed M. marinum. To mediate adsorption at a biological scale, GPs with different pore sizes and altered surface modifications were generated and assessed for the ability to adsorb MU and mycolactone. Macroporous GPs with and without stearic acid modification equivalently adsorbed MU cells, while mesoporous GPs with stearic acid adsorbed mycolactone toxin significantly better than mesoporous GPs or GPs modified with phenyltriethoxysilane (PTES). In cytotoxicity assays, Cu-nZeos lacked toxicity against Detroit 551, U-937, and WM-115 cells. GPs demonstrated limited cytotoxicity in Detroit 551 and WM-115, but produced time-dependent toxicity in U-937 cells. With their large surface area and adsorptive capacities, aluminosilicates nZeos and GPs may be modified and developed to support conventional BU wound care. Topical application of nZeos and GPs could kill MU within the cutaneous wound environment and physically remove MU and mycolactone with wound dressing changes, thereby improving wound healing and overall patient outcomes.

Estrategias de protección antimicrobiana en el cuidado de heridas: evidencia para el uso de apósitos recubiertos con DACC

BACKGROUND

Antimicrobial resistance (AMR) is one of the most serious health threats globally. The development of new antimicrobials is not keeping pace with the evolution of resistant microorganisms, and novel ways of tackling this problem are required. One of such initiatives has been the development of antimicrobial stewardship programmes (AMS). The use of wound dressings that employ a physical sequestration and retention approach to reduce bacterial burden offers a novel approach to support AMS. Bacterial-binding by dressings and their physical removal can minimise their damage and prevent the release of harmful endotoxins.

OBJECTIVE

To highlight AMS to promote the correct use of antimicrobials and to investigate how dialkylcarbamyl chloride (DACC)-coated dressings can support AMS.

METHOD

MEDLINE, Cochrane Database of Systematic Reviews, and Google Scholar were searched to identify articles relating to AMS, and the use of wound dressings in the prevention and treatment of wound infections. The evidence supporting alternative wound dressings that can reduce bioburden and prevent wound infection in a way that does not kill or damage the microorganisms were reviewed.

RESULTS

The evidence demonstrated that using bacterial-binding wound dressings that act in a physical manner (eg, DACC-coated dressings) to preventing infection in both acute and hard-to-heal wounds does not exacerbate AMR and supports AMS.

CONCLUSION

Some wound dressings work via a mechanism that promotes the binding and physical sequestration and removal of intact microorganisms from the wound bed (eg, a wound dressing that uses DACC technology to prevent/reduce infection). They provide a valuable tool that aligns with the requirements of AMS by effectively reducing wound bioburden without inducing/selecting for resistant bacteria.

Antimicrobial stewardship strategies in wound care: evidence to support the use of dialkylcarbamoyl chloride (DACC)- coated wound dressings

BACKGROUND

Traditionally, infections are treated with antimicrobials (for example, antibiotics, antiseptics, etc), but antimicrobial resistance (AMR) has become one of the most serious health threats of the 21st century (before the emergence of COVID-19). Wounds can be a source of infection by allowing unconstrained entry of microorganisms into the body, including antimicrobial-resistant bacteria. The development of new antimicrobials (particularly antibiotics) is not keeping pace with the evolution of resistant microorganisms and novel ways of addressing this problem are urgently required. One such initiative has been the development of antimicrobial stewardship (AMS) programmes, which educate healthcare workers, and control the prescribing and targeting of antimicrobials to reduce the likelihood of AMR. Of great importance has been the European Wound Management Association (EWMA) in supporting AMS by providing practical recommendations for optimising antimicrobial therapy for the treatment of wound infection. The use of wound dressings that use a physical sequestration and retention approach rather than antimicrobial agents to reduce bacterial burden offers a novel approach that supports AMS. Bacterial-binding by dressings and their physical removal, rather than active killing, minimises their damage and hence prevents the release of damaging endotoxins.

AIM

Our objective is to highlight AMS for the promotion of the judicious use of antimicrobials and to investigate how dialkylcarbamoyl chloride (DACC)-coated dressings can support AMS goals.

METHOD

MEDLINE, Cochrane Database of Systematic Reviews, and Google Scholar were searched to identify published articles describing data relating to AMS, and the use of a variety of wound dressings in the prevention and/or treatment of wound infections. The evidence supporting alternative wound dressings that can reduce bioburden and prevent and/or treat wound infection in a manner that does not kill or damage the microorganisms (for example, by actively binding and removing intact microorganisms from wounds) were then narratively reviewed.

RESULTS

The evidence reviewed here demonstrates that using bacterial-binding wound dressings that act in a physical manner (for example, DACC-coated dressings) as an alternative approach to preventing and/or treating infection in both acute and hard-to-heal wounds does not exacerbate AMR and supports AMS.

CONCLUSION

Some wound dressings work via a mechanism that promotes the binding and physical uptake, sequestration and removal of intact microorganisms from the wound bed (for example, a wound dressing that uses DACC technology to successfully prevent/reduce infection). They provide a valuable tool that aligns with the requirements of AMS (for example, reducing the use of antimicrobials in wound treatment regimens) by effectively reducing wound bioburden without inducing/selecting for resistant bacteria.

Genetics in the Host-Mycobacterium ulcerans interaction

Buruli ulcer is an emerging infectious disease associated with high morbidity and unpredictable outbreaks. It is caused by Mycobacterium ulcerans, a slow-growing pathogen evolutionarily shaped by the acquisition of a plasmid involved in the production of a potent macrolide-like cytotoxin and by genome rearrangements and downsizing. These events culminated in an uncommon infection pattern, whereby M. ulcerans is both able to induce the initiation of the inflammatory cascade and the cell death of its proponents, as well as to survive within the phagosome and in the extracellular milieu. In such extreme conditions, the host is sentenced to rely on a highly orchestrated genetic landscape to be able to control the infection. We here revisit the dynamics of M. ulcerans infection, drawing parallels from other mycobacterioses and integrating the most recent knowledge on its evolution and pathogenicity in its interaction with the host immune response.

Randomized Controlled Trial Evaluating Dialkylcarbamoyl Chloride Impregnated Dressings for the Prevention of Surgical Site Infections in Adult Women Undergoing Cesarean Section

Background: Surgical site infections (SSI) occur in 1.8%–9.2% of women undergoing cesarean section (CS) and lead to greater morbidity rates and increased treatment costs. The aim of the study was to evaluate the efficacy and cost-effectiveness of dialkylcarbamoyl chloride (DACC) impregnated dressings to prevent SSI in women subject to CS.

Methods: Randomized, controlled trial was conducted at the Mazovian Bródno Hospital, a tertiary care center performing approximately 1300 deliveries per year, between June 2014 and April 2015. Patients were randomly allocated to receive either DACC impregnated dressing or standard surgical dressing (SSD) following skin closure. In order to analyze cost-effectiveness of the selected dressings in the group of patients who developed SSI, the costs of ambulatory visits, additional hospitalization, nursing care, and systemic antibiotic therapy were assessed. Independent risk factors for SSI were determined by multivariable logistic regression.

Results: Five hundred and forty-three women undergoing elective or emergency CS were enrolled. The SSI rates in the DACC and SSD groups were 1.8% and 5.2%, respectively (p = 0.04). The total cost of SSI prophylaxis and treatment was greater in the control group as compared with the study group (5775 EUR vs. 1065 EUR, respectively). Independent risk factors for SSI included higher pre-pregnancy body mass index (adjusted odds ratio [aOR] = 1.08; [95% confidence interval [CI]: 1.0–1.2]; p < 0.05), smoking in pregnancy (aOR = 5.34; [95% CI: 1.6–15.4]; p < 0.01), and SSD application (aOR = 2.94; [95% CI: 1.1–9.3]; p < 0.05).

Conclusion: The study confirmed the efficacy and cost-effectiveness of DACC impregnated dressings in SSI prevention among women undergoing CS.

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.