Giant cutaneous ulcer in Epstein-Barr virus positive T-cell/NK-cell lymphoproliferative disorder: A case report

BACKGROUND

Epstein-Barr virus (EBV)-positive T-cell/natural killer (NK)-cell lymphoproliferative disorder is a rare but challenging condition that requires multidisciplinary teamwork, including co-management by infection medicine, radiotherapy, rehabilitation, and psychology experts, as well as wound specialist nurses.

CASE SUMMARY

The patient was a 33-year-old female who presented with an erythema-like lesion on the left upper extremity that became desquamated and then blistered and eventually became a giant ulcer with exposed nerves and muscles. The left wrist had a fixed posture, and pathology tests showed cutaneous EBV-positive NK/T-cell proliferative disease. We employed a multidisciplinary collaborative treatment approach, and after 13 wound changes over 45 days, combined with radiation therapy, dietary supplementation, and psychosocial therapy, the left upper extremity wound healed.

CONCLUSION

Giant ulcers caused by cutaneous EBV-positive NK/T-cell proliferative disease can be treated using a multidisciplinary collaborative approach.

Development of a tri-species wound model for studying fungal-bacterial interactions and antimicrobial therapies

Chronic wounds are increasing in numbers and biofilm-producing bacteria are highly prevalent in these wounds and often create resilient polymicrobial infections. Moreover, estimates suggest that up to 23 % of wounds contain fungi, particularly Candida albicans. Currently, inter-kingdom chronic wound models are scarce; thus, this study presents one of the few in vitro models that incorporate both bacterial and fungal species in a wound-relevant environment, addressing a critical gap in current biofilm research. The newly developed model contained the commonly isolated wound bacteria Pseudomonas aeruginosa and Staphylococcus aureus, and the fungus Candida albicans. Inter-species interactions were investigated through selective plate counting and pH and oxygen measurements, as well as confocal microscopy. Investigations were carried out before and after exposure to commonly used clinical antimicrobial treatments, including silver-infused bandages. When grown in a tri-species consortium, P. aeruginosa and S. aureus exhibited a higher tolerance towards silver-infused bandages than when they were grown individually. This suggests that C. albicans plays a protective role for the bacteria. In addition, the treatment also caused a shift in species ratios, moving from a P. aeruginosa-dominated consortium to a S. aureus-dominated consortium. Moreover, confocal microscopy revealed a change in biofilm architecture when comparing single-species models to tri-species models. Finally, we observed that silver-infused bandages increased the pH in the tri-species model as well as partially restoring the oxygenation within the wound model. In conclusion, our novel model exemplifies how inter-kingdom interactions in fungal-bacterial infections can complicate both the microenvironment and treatment efficacy.

Biofilm-mediated infections; novel therapeutic approaches and harnessing artificial intelligence for early detection and treatment of biofilm-associated infections

A biofilm is a group of bacteria that have self-produced a matrix and are grouped together in a dense population. By resisting the host's immune system's phagocytosis process and attacking with anti-microbial chemicals such as reactive oxygen and nitrogen species, a biofilm enables pathogenic bacteria to evade elimination. One of the major problems in managing chronic injuries is treating wounds colonized by biofilms. These days, a major issue is the biofilms, which exacerbate infection pathogenesis and severity. Numerous investigators have already discovered cutting-edge methods for biofilm manipulation. Using phytochemicals is a practical tactic to control and prevent the production of biofilms. Numerous studies conducted in the last few years have demonstrated the antibacterial and antibiofilm qualities of nanoparticles (NPs) against bacteria, fungi, and protozoa. Because hydrogel has antibiofilm properties, it has been employed extensively in wound care recently. It may be removed with ease and without causing trauma. Today, artificial intelligence (AI) is being used to improve these tactics by providing customized treatment alternatives and predictive analytics. Artificial intelligence (AI) algorithms have the capability to examine extensive datasets and detect trends in biofilm formation and resistance mechanisms. This can aid in the creation of more potent antimicrobial drugs. AI models analyze complex datasets, predict biofilm formation, and guide the design of personalized treatment strategies by identifying resistance mechanisms and therapeutic targets with exceptional precision. This review provides an integrative perspective on biofilm formation mechanisms and their role in infections, highlighting the innovative applications of AI in this domain. By integrating data from diverse biological systems, AI accelerates drug discovery, optimizes treatment regimens, and enables real-time monitoring of biofilm dynamics. From predictive analytics to personalized care, we explore how AI enhances biofilm diagnostics and introduces precision medicine in biofilm-associated infections. This approach not only addresses the limitations of traditional methods but also paves the way for revolutionary advancements in infection control, antimicrobial resistance management, and improved patient outcomes.

Zinc Oxide@Tetracycline Spiky Microparticles Design for Persistent Antibacterial Therapy

Antibiotics have revolutionized medical treatment by effectively combating bacterial infections, particularly those associated with chronic wounds and implant complications. Nevertheless, the persistent use of these drugs has resulted in an increase in antibiotic-resistant bacteria and biofilm infections, highlighting the urgent need for alternative therapies. This study presents an approach for combating persistent bacterial and biofilm infections through the integration of biomimetic design and advanced nanotechnology. Inspired by the natural defense mechanisms of pollen grains and lotus leaves, we engineered zinc oxide spiky microparticles combined with tetracycline-loaded beads mimicking the structure of lotus leaf papillae. This biomimetic design exhibits a multifaceted antimicrobial strategy, leveraging hierarchical micro/nanostructures and the inherent antibacterial properties of their natural counterparts. ZnO microparticles, which mimic the morphology of pollen grains, provide topological cues to rupture adhered bacteria, whereas tetracycline beads, inspired by lotus leaf papillae, deliver a controlled release of antibiotics to target persistent bacteria. Using a synergistic multimodal approach, our biomimetic materials demonstrated exceptional efficacy in eradicating persistent methicillin-resistant Staphylococcus aureus and Escherichia coli infections, offering promising prospects for the development of advanced antibacterial therapies. This study not only underscores the importance of biomimicry in material design but also highlights the potential of integrating nature-inspired strategies with nanotechnology for biomedical applications.

Spray-drying-engineered CS/HA-bilayer microneedles enable sequential drug release for wound healing

High incidence and mortality rates of chronic wounds place a heavy burden on global healthcare systems. Achieving phased delivery of antimicrobial and regenerative drugs is crucial for promoting chronic wound healing. Herein, a microneedle (MN) patch with a biphasic release system was developed using a combination of solvent casting and spraying methods. Additionally, a copper/PDMS mold was introduced to address the issue of deformation in the chitosan material during drying on polydimethylsiloxane (PDMS). The MNs have a bilayer structure, with a hyaluronic acid (HA) coating loaded with doxycycline (DOX) for antibacterial action and a chitosan (CS) core loaded with vascular endothelial growth factor (VEGF) for promoting cell migration and proliferation. Notably, in vitro drug release studies showed that the coating drug was released by 98.8% within 10 hours, while the release of the core drug could be sustained for up to 70 hours. In vivo studies showed that chronic wounds on C57 mice treated with CS/HA-bilayer MNs achieved nearly complete healing by day 9. These wounds exhibited reduced inflammatory cell infiltration, increased epithelial tissue regeneration, and enhanced collagen deposition. This work integrates the staged management of bacterial infection and angiogenesis and offers promising prospects for enhancing chronic wound healing.

Investigating the Prevalence of Fungi in Diabetic Ulcers: An Under-Recognised Contributor to Polymicrobial Biofilms

Diabetic foot ulcers (DFUs) are common complications for diabetic patients, often exacerbated by complex polymicrobial biofilm infections. While the majority of DFU studies are bacterial focused, fungi have also been identified. This study aims to investigate the prevalence of fungi in DFUs, as well as their potential role and influence on persistence and wound healing. Consecutive DFU swabs were collected from 128 patients (n = 349). Fungal positivity was assessed using enhanced culture and real-time qPCR. Routine microbiology cultures were carried out as part of standard care in the clinics, and their results were then compared to our laboratory investigation. Routine and enhanced culture resulted in similar rates of fungal detection (~9%), whereas qPCR resulted in a higher rate of detection (31%). Notably, the predominant yeast Candida parapsilosis was present in ischaemic and penetrating bone wounds. These findings support existing evidence of fungal presence in DFUs. We demonstrated that routine diagnostic methods are sufficient for fungal detection, but enhanced culture methods allow for more precise fungal identification. Finally, while fungal presence does not appear to impact patient outcomes in our study, their role within these infections remains poorly understood, and further studies are needed to fully understand their relationship to the microbiome.

Addressing the Dressings: Wound Care in Hidradenitis Suppurativa

Hidradenitis suppurativa (HS) wounds are complex and have unique characteristics that complicate dressing selection. Proper wound care assists with wound healing and contributes to improved quality of life. Ideal dressings are comfortable while maintaining a wound-healing environment. Antimicrobial dressings should target dysbiosis and biofilms. Absorptive dressings are needed for control of exudate. Pain control is best achieved with nonadhesive dressings and contact layers. Agents targeting anaerobic bacteria are effective at odor reduction. Surgery may be indicated for management of refractory wounds. Overall, there is a need for increased research and education on both routine and postsurgical wound care in HS.

Antimicrobial and anti-inflammatory effects of polyethyleneimine-modified polydopamine nanoparticles on a burn-injured skin model

Chronic infections involving bacterial biofilms pose significant treatment challenges due to the resilience of biofilms against existing antimicrobials. Here, we introduce a nanomaterial-based platform for treating Staphylococcus epidermidis biofilms, both in isolation and within a biofilm-infected burn skin model. Our approach leverages biocompatible and photothermal polydopamine nanoparticles (PDNP), functionalized with branched polyethyleneimine (PEI) and loaded with the antibiotic rifampicin, to target bacteria dwelling within biofilms. A key innovation of our method is its ability to not only target planktonic S. epidermidis but also effectively tackle biofilm-embedded bacteria. We demonstrated that PDNP-PEI interacts effectively with the bacterial surface, facilitating laser-activated photothermal eradication of planktonic S. epidermidis. In a 3D skin burn injury model, PDNP-PEI demonstrates anti-inflammatory and reactive oxygen species (ROS)-scavenging effects, reducing inflammatory cytokine levels and promoting healing. The rifampicin-loaded PDNP-PEI (PDNP-PEI-Rif) platform further shows significant efficacy against bacteria inside biofilms. The PDNP-PEI-Rif retained its immunomodulatory activity and efficiently eradicated biofilms grown on our burn-injured 3D skin model, effectively addressing the challenges of biofilm-related infections. This achievement marks a significant advancement in infection management, with the potential for a transformative impact on clinical practice.

Effectiveness of an enhanced silver-containing dressing in hard-to-heal venous leg ulcers: a randomised controlled trial

OBJECTIVE

To assess the efficacy and safety of a carboxymethylcellulose dressing containing ionic silver, ethylenediaminetetraacetic acid and benzethonium chloride (CISEB) versus a dialkylcarbamoyl chloride-coated dressing (DACC) in hard-to-heal venous leg ulcers (VLUs).

METHOD

In a multinational, multicentre, randomised controlled trial, patients with hard-to-heal VLUs were randomised 1:1 to receive CISEB (n=100) or DACC (n=103) for up to four weeks. VLUs that were not healed by week 4 were managed with standard of care for up to 12 weeks or until healed (whichever was sooner). The primary endpoint was complete wound closure at week 12. Additional endpoints included time to complete wound closure and incidence of adverse events (AEs).

RESULTS

The trial cohort included 203 patients. CISEB achieved a higher rate of complete wound closure by week 12 compared to DACC (74.8% versus 55.6%, respectively; p<0.0031), and was associated with a 35% increased likelihood of healing (risk ratio, 1.35; 95% confidence interval: 1.10-1.65). Median time to complete wound closure was shorter in the CISEB arm (56 days) compared to the DACC arm (70 days; p<0.0272). A smaller proportion of patients experienced an AE with CISEB compared to DACC (5.0% versus 17.6%, respectively).

CONCLUSION

Management of hard-to-heal VLUs with CISEB was associated with improved healing outcomes compared to DACC, without additional safety concerns. CISEB is a gelling fibre dressing with antimicrobial, metal-chelating and surfactant components that may promote an optimal healing environment to address the challenge of hard-to-heal wounds.

Protection with a collagen wound matrix containing polyhexamethylene biguanide supports innate wound healing in biofilm-infected porcine wounds

Over 90% of chronic wounds have biofilm infections, making the need for inhibiting reformation of biofilm post-debridement paramount to support progression through the normal phases of wound healing. Herein, we describe a porcine wound model infected with methicillin-resistant Staphylococcus aureus (MRSA) and examine the ability of an antimicrobial barrier composed of native type I collagen and polyhexamethylene biguanide (PCMP) to serve as a barrier to protect wounds and support progression through the innate wound healing cascade. Wounds were inoculated with MRSA and allowed to form a biofilm for 72 h, subjected to standard of care sharp debridement, then either left untreated or received PCMP for 5, 10, 15 or 20 days. Wounds were assessed for bioburden, wound closure and expression of genes related to wound healing. Wounds treated with PCMP exhibited statistically lower MRSA levels compared to untreated controls and achieved 90% closure by 2 weeks of treatment. Gene expression analysis demonstrated that by reducing bacterial load, wounds progressed through the innate wound healing cascade, while untreated wounds exhibited a dampening of the immune response. Additionally, for randomly assigned wounds, PCMP was not reapplied at dressing changes to assess the impact of inconsistent wound protection. At all timepoints, a resurgence in bioburden was observed following removal of PCMP if the wounds had not fully closed. This study highlights the value of PCMP as an antimicrobial barrier and the importance of protecting wounds through closure and resolution.

The Antifungal Activity of a Polygalacturonic and Caprylic Acid Ointment in an In Vitro, Three-Dimensional Wound Biofilm Model

Candida colonization and biofilms are significant contributors to impaired wound healing. Consequently, improved treatments are needed to eradicate Candida biofilms in wounds. Wounds present complex biofilm extracellular matrix environments, with microbial cells frequently enmeshed in matrices comprising wound exudate macromolecular gels. We evaluated the ability of a polygalacturonic and caprylic acid (PG + CAP) ointment to eradicate Candida albicans, C. parapsilosis, C. glabrata, C. tropicalis, and C. auris biofilms in a fibrin gel wound biofilm model of the complex wound biofilm environment. Hypochlorous acid (HOCl) is a disinfecting antimicrobial agent that is widely used as wound irrigant, and this was used as a comparator. A single treatment with PG + CAP reduced the number of viable organisms in the C. albicans and C. glabrata biofilms by over 5 log10, in the C. parapsilosis and C. auris biofilms by over 4 log10, and in the C. tropicalis biofilm by 3.85 log10. PG + CAP was superior (p < 0.01) to HOCl in eradicating all Candida species biofilms, except for C. auris, for which both treatments fully eradicated all viable organisms. The use of HOCl in Candida-colonized wounds should include consideration of the extracellular matrix load in the wound bed. PG + CAP warrants further study in wounds compromised by Candida biofilms.

Out of this World: Wound Healing on Earth and in Space

Impaired wound healing is a significant concern for humans in space, where the unique microgravity environment poses challenges to the natural healing processes of the body. Similar to chronic wounds on earth, such as diabetic foot ulcers and venous leg ulcers, wounds inflicted in space exhibit delayed or impaired healing responses. These wounds share common features, including dysregulated cellular signaling, altered cytokine profiles, and impaired tissue regeneration. Little is known about the mechanisms underlying wound healing under microgravity. In this review, we focused on exploring the parallels between wound healing in space and chronic wounds on earth as a fundamental approach for developing effective countermeasures to promote healing and mitigate associated health risks during long-space missions.

Silk Composite-Based Multifunctional Pellets for Controlled Release

Chronic wounds present significant clinical challenges due to the high risk of infections and persistent inflammation. While personalized treatments in point-of-care settings are crucial, they are limited by the complex fabrication techniques of the existing products. The calcium sulfate hemihydrate (CSH)-based drug delivery platform enables rapid fabrication but lacks antioxidant and antibacterial properties, essential to promote healing. To develop a multifunctional platform, a tannic acid (TA)-silk fibroin (SF) complex is engineered and incorporated as an additive in CSH cement. This cement is then cast into pellets to create silk/bioceramic-based composite drug delivery systems, designed for point-of-care use. Compared to neat CSH pellets, the composite pellets exhibit a 7.5-fold increase in antioxidant activity and prolonged antibacterial efficacy (up to 13 d). Moreover, the subcutaneous implantation of the pellets shows no hallmarks of local or systemic toxicity in a rodent model. The pellets are optimized in composition and fabrication to ease market translation. Clinically, the pellets have the potential to be further developed into products to place on wound beds or fill into bone cavities that are designed to deliver the intended therapeutic effect. The developed multifunctional system proves to be a promising solution for personalized treatment in point-of-care settings.

Photoimmunologic Therapy of Stubborn Biofilm via Inhibiting Bacteria Revival and Preventing Reinfection

Stubborn biofilm infections pose serious threats to public health. Clinical practices highly rely on mechanical debridement and antibiotics, which often fail and lead to persistent and recurrent infections. The main culprits are 1) persistent bacteria reviving, colonizing, and rejuvenating biofilms, and 2) secondary pathogen exposure, particularly in individuals with chronic diseases. Addressing how to inhibit persistent bacteria revival and prevent reinfection simultaneously is still a major challenge. Herein, an oligo-ethylene glycol-modified lipophilic cationic photosensitizer (PS), TBTCP-PEG7, is developed. It effectively eradicates Methicillin-Resistant Staphylococcus aureus (MRSA) under light irradiation. Furthermore, TBTCP-PEG7-mediated photodynamic therapy (PDT) not only conquers stubborn biofilm infections by downregulating the two-component system (TCS), quorum sensing (QS), and virulence factors, thereby reducing intercellular communication, inhibiting persistent bacterial regrowth and biofilm remodeling but also prevents reinfection by upregulating heat shock protein-related genes to induce immunogenetic cell death (ICD) and establish immune memory. In vivo, TBTCP-PEG7 efficiently eradicates MRSA biofilm adhered to medical catheters, stimulates angiogenesis, reduces inflammatory factor expression, and accelerates wound healing. Furthermore, ICD promotes short-term immune and long-term immunological memory for coping with secondary infections. This two-pronged strategy not only effectively overcomes stubborn, persistent and recurrent biofilm infection, but also provides theoretical guidance for designing the next generation of antibacterial materials.

The Wound Reporting in Animal and Human Preclinical Studies (WRAHPS) Guidelines

Preclinical studies for wound healing disorders are an essential step in translating discoveries into therapies. Also, they are an integral component of initial safety screening and gaining mechanistic insights using an in vivo approach. Given the complexity of the wound healing process, existing guidelines for animal testing do not capture key information due to the inevitable variability in experimental design. Variations in study interpretation are increased by complexities associated with wound aetiology, wounding procedure, multiple treatment conditions, wound assessment, and analysis, as well as lack of acknowledgement of limitation of the model used. Yet, no standards exist to guide reporting crucial experimental information required to interpret results in translational studies of wound healing. Consistency in reporting allows transparency, comparative, and meta-analysis studies and avoids repetition and redundancy. Therefore, there is a critical and unmet need to standardise reporting for preclinical wound studies. To aid in reporting experimental conditions, The Wound Reporting in Animal and Human Preclinical Studies (WRAHPS) Guidelines have now been created by the authors working with the Wound Care Collaborative Community (WCCC) GAPS group to provide a checklist and reporting template for the most frequently used preclinical models in support of development for human clinical trials for wound healing disorders. It is anticipated that the WRAHPS Guidelines will standardise comprehensive methods for reporting in scientific manuscripts and the wound healing field overall. This article is not intended to address regulatory requirements but is intended to provide general guidelines on important scientific considerations for such studies.

Harnessing the Power of Our Immune System: The Antimicrobial and Antibiofilm Properties of Nitric Oxide

Nitric oxide (NO) is a free radical of the human innate immune response to invading pathogens. NO, produced by nitric oxide synthases (NOSs), is used by the immune system to kill microorganisms encapsulated within phagosomes via protein and DNA disruption. Owing to its ability to disperse biofilm-bound microorganisms, penetrate the biofilm matrix, and act as a signal molecule, NO may also be effective as an antibiofilm agent. NO can be considered an underappreciated antimicrobial that could be levied against infected, at-risk, and hard-to-heal wounds due to the inherent lack of bacterial resistance, and tolerance by human tissues. NO produced within a wound dressing may be an effective method of disrupting biofilms and killing microorganisms in hard-to-heal wounds such as diabetic foot ulcers, venous leg ulcers, and pressure injuries. We have conducted a narrative review of the evidence underlying the key antimicrobial and antibiofilm mechanisms of action of NO for it to serve as an exogenously-produced antimicrobial agent in dressings used in the treatment of hard-to-heal wounds.

Smart drug delivery and responsive microneedles for wound healing

Wound healing is an ongoing concern for the medical community. The limitations of traditional dressings are being addressed by materials and manufacturing technology. Microneedles (MNs) are a novel type of drug delivery system that has been widely used in cancer therapy, dermatological treatment, and insulin and vaccine delivery. MNs locally penetrate necrotic tissue, eschar, biofilm and epidermis into deep tissues, avoiding the possibility of drug dilution and degradation and greatly improving administration efficiency with less pain. MNs represent a new direction for wound treatment and transdermal delivery. In this study, we summarise the skin wound healing process and the mechanical stimulation of MNs in the context of the wound healing process. We also introduce the structural design and manufacture of MNs. Subsequently, MNs are categorised according to the loaded drugs, where the design of the MNs according to the traumatic biological/biochemical microenvironment (pH, glucose, and bacteria) and the physical microenvironment (temperature, light, and ultrasound) is emphasised. Finally, the advantages of MNs are compared with traditional drug delivery systems and their prospects are discussed.

Marine polysaccharides for antibiofilm application: A focus on biomedical fields

Microbial pathogens such as bacteria and fungi form biofilms, which represent substantial hurdles in treating human illness owing to their adaptive resistance mechanism to conventional antibiotics. Biofilm may cause persistent infection in a variety of bodily areas, including wounds, oral cavity, and vaginal canal. Using invasive devices such as implants and catheters contributes significantly to developing healthcare-associated infections because they offer an ideal surface for biofilm formation. Marine organisms produce a variety of polysaccharides, which have recently attracted worldwide attention due to their biochemical features, various applications, and advantageous properties such as bioactivity, biodegradability, and biocompatibility. Because of their antimicrobial and antibiofilm features, several polysaccharides such as chitosan, fucoidan, carrageenan, alginate, and hyaluronic acid have been used to treat infected wounds as well as ophthalmic, oral, and vaginal infections. In addition, marine polysaccharides are currently employed as coatings on medical devices and implant materials, alone or in combination with other bioactive substances or nanomaterials, to protect the materials' undertones from microbial contamination. This review discussed the recent advancements in marine polysaccharides and their derivatives as a therapeutic potential against biofilm-associated diseases. The potential obstacles in the scalability of their production, clinical translation, and/or regulatory hurdles have also been discussed.

Essential oils: a potential alternative with promising active ingredients for pharmaceutical formulations in chronic wound management

Chronic wound is a major clinical challenge that complicates wound healing, mainly associated with bacterial biofilms. Bacterial burden damages tissue and persists inflammation, failing to granulate, leading to morbidity and mortality. Various therapeutic strategies and approaches have been developed for chronic wound healing in clinical practice. As treating biofilm infection is crucial in chronic wounds, a potent antibiofilm agent, essential oils have been explored extensively for their therapeutic properties and as a replacement for antibiotic therapy. Currently, several studies on essential oils and their active compounds in therapeutics, such as adjunctive therapies, nanotechnology-based treatment and their drug delivery systems, help heal chronic wounds. The antimicrobial, anti-inflammatory and antioxidant properties of essential oils make them distinct and are renowned as natural remedies to improve the healing of infected chronic wounds. Consequently, it accelerates wound closure by reducing inflammation, increasing angiogenesis and tissue regeneration. This review focuses on different essential oils and their active compounds that are exploited for the treatment of biofilm infection, chronic inflammation and wound healing. Thus, an effective novel treatment can be developed to improve the current treatment strategy to overcome multidrug resistance bacteria or antibiotic resistance in various chronic wound infections that support wound healing.

H2Se-evolving bio-heterojunctions promote cutaneous regeneration in infected wounds by inhibiting excessive cellular senescence

Pathogenic infection leads to excessive senescent cell accumulation and stagnation of wound healing. To address these issues, we devise and develop a hydrogen selenide (H2Se)-evolving bio-heterojunction (bio-HJ) composed of graphene oxide (GO) and FeSe2 to deracinate bacterial infection, suppress cellular senescence and remedy recalcitrant infected wounds. Excited by near-infrared (NIR) laser, the bio-HJ exerts desired photothermal and photodynamic effects, resulting in rapid disinfection. The crafted bio-HJ could also evolve gaseous H2Se to inhibit cellular senescence and dampen inflammation. Mechanism studies reveal the anti-senescence effects of H2Se-evolving bio-HJ are mediated by selenium pathway and glutathione peroxidase 1 (GPX1). More critically, in vivo experiments authenticate that the H2Se-evolving bio-HJ could inhibit cellular senescence and potentiate wound regeneration in rats. As envisioned, our work not only furnishes the novel gasotransmitter-delivering bio-HJ for chronic infected wounds, but also gets insight into the development of anti-senescence biomaterials.

Enhancing wound healing through sonodynamic silver/barium titanate heterostructures-loading gelatin/PCL nanodressings

Bacterial infections present a formidable challenge in surgical procedures, and are a major threat to wound healing. Sonodynamic therapy (SDT) is a non-invasive approach for fighting pathogens; however, it is hindered by the efficiency of sonosensitizers and effective antibacterial time. In this study, we developed a biocompatible nanodressing to improve the antibacterial efficacy and accelerate wound healing via SDT. Silver nanoparticles (NPs) were synthesized on tetragonal barium titanate (BTO) NPs to create an Ag@BTO heterostructure of sonosensitizers to improve their piezocatalytic activities, which were then incorporated into gelatin/polycaprolactone (PCL) to form Ag@BTO-gelatin/PCL nanofiber (ABT-gP NFs) dressings. The loading of Ag@BTO NPs resulted in ABT-gP NFs with better mechanical properties and excellent piezocatalysis, which produced reactive oxygen species and Ag+ to kill bacteria during ultrasound (US) irradiation. Additionally, nanodressing released moderate amounts of silver ions without US, prolonging the antibacterial time, while promoting fibroblast migration. This approach was effective in killing Gram-positive and Gram-negative bacteria (100 % and 90.8 %, respectively), promoting cell migration in vitro and accelerating wound healing without adverse effects in vivo. This study extends the potential applications of ultrasound-triggered nanodressing to the field of wound healing.

The influence of marine fungal meroterpenoid meroantarctine A toward HaCaT keratinocytes infected with Staphylococcus aureus

A new biological activity was discovered for marine fungal meroterpenoid meroantarctine A with unique 6/5/6/6 polycyclic system. It was found that meroantarctine A can significantly reduce biofilm formation by Staphylococcus aureus with an IC50 of 9.2 µM via inhibition of sortase A activity. Co-cultivation of HaCaT keratinocytes with a S. aureus suspension was used as an in vitro model of skin infection. Treatment of S. aureus-infected HaCaT cells with meroantarctine A at 10 µM caused a reduction in the production of TNF-α, IL-18, NO, and ROS, as well as LDH release and caspase 1 activation in these cells and, finally, recovered the proliferation and migration of HaCaT cells in an in vitro wound healing assay up to the control level. Thus, meroantarctine A is a new promising antibiofilm compound which can effective against S. aureus caused skin infection.

Eradication of Candida auris biofilm in vitro by a polygalacturonic and caprylic acid wound ointment

Candida auris is a rapidly spreading virulent pathogen frequently resistant to multiple antifungal drugs that can form biofilms and infect wounds. Hence, there is a need for C. auris wound treatments not posing risks for developing antifungal resistance. We tested the ability of a polygalacturonic and caprylic acid ointment (PG+CAP) to rapidly eradicate C. auris biofilms within 2-hour exposures in an in vitro model. Medical-grade honey (MediHoney) wound ointment was used as a comparator. Nine different C. auris strains were tested. PG+CAP eradicated biofilms of 8 of the 9 tested strains and produced a > 5-log10 reduction of the ninth. MediHoney produced reductions ranging from 2 to 4 log10 without fully eradicating any strains. The differences between PG+CAP and MediHoney were statistically significant (p < 0.05). These results suggest that PG+CAP is a promising antimicrobial ointment warranting further in vivo study in wounds which may be colonized by C. auris biofilms.

Wound Gel Formulations Containing Poloxamer 407 and Polyhexanide Have In Vitro Antimicrobial and Antibiofilm Activity Against Wound-Associated Microbial Pathogens

Chronic wounds are often caused or exacerbated by microbial biofilms that are highly resistant to antimicrobial treatments and that prevent healing. This study compared the antimicrobial and antibiofilm activity of nine topical wound treatments, comprising gels with different concentrations of poloxamer 407 (20-26%) and different pH levels (4-6) and containing polyhexanide (PHMB) as an antimicrobial agent; the effects of pH on wound gels containing this agent have not been previously reported. The wound gel formulations were tested against six common wound-associated microbial pathogens: Staphylococcus aureus, S. epidermidis, Pseudomonas aeruginosa, Escherichia coli, Acinetobacter baumannii, and Candida albicans. Time-kill assays were used to assess antimicrobial activity against planktonic forms of each species, and a colony biofilm model was used to assess antibiofilm activity against existing biofilms as well as inhibition of new biofilm formation. Biofilm inhibition activity was also assessed in the presence of common wound dressing materials. Wound gels with higher pH levels exhibited stronger antimicrobial activity, while poloxamer 407 concentrations >20% negatively impacted antimicrobial activity. Wound gel formulations were identified that had antimicrobial, antibiofilm, and biofilm inhibition activity against all tested species in vitro. Biofilm inhibition activity was not affected by contact with common wound dressings. Further development of these wound gels may provide a valuable new option for the treatment and prevention of chronic wounds.

Prevalence of Extended-Spectrum Beta-Lactamase Producer Gram-Negative Rods and Associated Factors Among Patients With Wound Infection at University of Gondar Comprehensive Specialized Hospital, Northwest Ethiopia

Background: Multidrug-resistant (MDR) bacteria have significantly affected the management and treatment of wound infections globally. Data on the prevalence of MDR bacterial profiles that cause wound infections in Ethiopia are scarce. Therefore, this study aimed to determine MDR as well as extended-spectrum beta-lactamase production profiles of Gram-negative rods that are difficult to treat with conventional antibiotics and that cause wound infections. Objective: The aim of the study was to determine the prevalence of extended-spectrum beta-lactamase producer Gram-negative rods and associated factors among patients with wound infection at University of Gondar Comprehensive Specialized Hospital, northwest Ethiopia. Materials and Methods: This hospital-based cross-sectional study was conducted at University of Gondar Comprehensive Specialized Hospital between May and July 2022. Convenience sampling was used to recruit 228 participants. Swabs from different wound types were inoculated onto the MacConkey agar and blood agar plates and incubated overnight at 37°C for 24 h. Biochemical tests were performed on isolated colonies for the identification of bacterial species based on their biochemical reaction. Antimicrobial susceptibility tests were performed using the disk diffusion technique as per the standard Kirby-Bauer method by using Muller-Hinton agar, and the zone of inhibition was interpreted as resistant, intermediate, and sensitive as per the recommendation of Clinical Laboratory Standard Institute. Isolates were tested against ceftriaxone, cefotaxime, and ceftazidime for extended-spectrum beta-lactamase screening using the Kirby-Bauer disk diffusion method, and combined disk tests were applied for phenotypic confirmatory test of extended-spectrum beta-lactamase producing isolates. Result: Of 228 study participants, 162 (71.1%) were culture-positive. Among culture-positive patients, 165 Gram-negative bacteria were recovered. The most common Gram-negative isolates were Pseudomonas aeruginosa (47; 28.5%), followed by Escherichia coli (43; 26.1%) and Klebsiella pneumoniae (24; 14.5%). The susceptibility rates of the isolate for imipenem and tobramycin were 97.0% and 73.2%, respectively, and the overall multidrug resistance rate was 80.5%. Extended-spectrum beta-lactamase producer bacteria were also isolated. Besides, all (100%) of extended-spectrum beta-lactamase producer bacteria were MDR. Living in rural areas (AOR 5.8; 95% CI [2.01-16.7]), hospital admission (AOR 3.95; 95% CI [1.13-13.83]), antibiotic use (AOR 2.83; 95% CI [1.03-7.72]), and comorbidity (AOR 0.25; 95% CI [0.07-0.59]) were significantly associated with wound infection. Conclusions and Recommendations: There was a high prevalence of Gram-negative bacterial isolates in this study. Pseudomonas aeruginosa (28.5%) was the predominant isolate. In addition, high rates of multidrug resistance were observed. The high level of multidrug resistance in this study implies that definitive therapy should be based on culture and susceptibility analysis to promote the rational use of antibiotics and to reduce the emergence of bacterial resistance to antimicrobials.

Association of biofilm and microbial metrics with healing rate in older adults with chronic venous leg ulcers

The presence of microbial biofilms in many human chronic wounds led to the hypothesis that biofilms delay healing of these wounds. We tested this hypothesis in a population of 117 older individuals with venous leg ulcers who were receiving standardised therapy, including frequent debridement. Debridement specimens were analysed for the amount of bacterial biomass by two independent methods: a microscopic approach that scored the relative size and number of bacterial aggregates, interpreted as a biofilm metric, and conventional enumeration by agar plating for viable bacteria. The plating protocol yielded three distinct values: the total viable bacterial count, bleach-tolerant bacteria, and the log reduction in viable bacteria upon bleach treatment. Wound healing rates over an 8-week observation period were calculated as the rate of decrease of the equivalent diameter of the wound. There was no statistically significant association between wound healing and the biofilm metric in any of the three analyses performed (p ≥0.15). In all three statistical tests, wound healing was associated with the log reduction caused by bleach treatment (p ≤0.004); wounds that harboured bacteria that were more bleach-susceptible healed more slowly. A refinement of the model of chronic wound infection pathogenesis is proposed in which dormant bacteria constitute a persistent nidus and outgrowth of metabolically active cells impairs healing. This model constitutes a new hypothesis as metabolic activity was not directly measured in this investigation.

Patients with venous leg ulcers can be managed safely in the community ----results of an observational comparison study in Singapore

AIM

To examine the healing outcomes of patients with venous leg ulcers requiring compression bandaging in community care versus tertiary care.

METHOD

This was an analytical observational cohort study. Venous leg ulcer (VLU) patients who required compression bandaging were recruited from an outpatient vascular clinic between May 2021 and August 2022. Eligible patients received two-or four-layer compression bandaging and followed up with the community care or tertiary care centre nurses. The primary outcome was the difference in the total surface area of the VLU after 12 weeks, and the secondary outcome was the patient's quality of life, as measured by the Cardiff Wound Impact Schedule (CWIS).

RESULTS

Forty-seven VLU patients were recruited; 27 received compression bandaging in the community care and 20 by the tertiary care centre. Mean age 70 years old (SD 11.04). The two most prevalent comorbidities were hypertension (51.06 %) and diabetes mellitus (38.29 %). Among those who completed follow-up (12 weeks), the median difference of the total surface area of the VLU between community-based care (p = 0.02) versus tertiary-based care (0.003) was significant. However, there was no difference in the healing status between community and tertiary-based care (p = 0.68). There was no difference in the quality of life of patients between groups.

CONCLUSION

This first tropical study comparing VLU healing outcomes between community and tertiary care found no significant difference in healing with compression bandaging by nurses in either setting. However, the small sample size and high dropout rate limit the generalizability of the findings, necessitating a larger-scale study with longer follow-up. Despite these limitations, the study is a crucial step toward improving wound care services in Singapore, and highlights the need for further research to guide future community wound care implementation.

Anaerobic bacteria in chronic wounds: Roles in disease, infection and treatment failure

Infection is among the most common factors that impede wound healing, yet standard treatments routinely fail to resolve chronic wound infections. The chronic wound environment is largely hypoxic/anoxic, and wounds are predominantly colonised by facultative and obligate anaerobic bacteria. Oxygen (O2) limitation is an underappreciated driver of microbiota composition and behaviour in chronic wounds. In this perspective article, we examine how anaerobic bacteria and their distinct physiologies support persistent, antibiotic-recalcitrant infections. We describe the anaerobic energy metabolisms bacteria rely on for long-term survival in the wound environment, and why many antibiotics become less effective under hypoxic conditions. We also discuss obligate anaerobes, which are among the most prevalent taxa to colonise chronic wounds, yet their potential roles in influencing the microbial community and wound healing have been overlooked. All of the most common obligate anaerobes found in chronic wounds are opportunistic pathogens. We consider how these organisms persist in the wound environment and interface with host physiology to hinder wound healing processes or promote chronic inflammation. Finally, we apply our understanding of anaerobic physiologies to evaluate current treatment practices and to propose new strategies for treating chronic wound infections.

Biofilm and Its Characteristics in Venous Ulcers

PURPOSE

The aim of the study was to analyze the characteristics of the biofilm of venous ulcers in terms of location and formation and to relate the presence of the biofilm to ulcer characteristics including duration, injured area, and necrotic tissue.

DESIGN

Descriptive clinical study.

MATERIALS AND METHODS

We obtained 2 biopsy fragments (tissue samples) from 44 patients with venous ulcers treated at a public outpatient clinic in a university hospital in Belo Horizonte, Brazil. Ulcers were photographed and classified according to the duration. In addition, the wound size and proportion of wound surface covered by necrotic tissue were measured. One fragment from each ulcer underwent microbiological analysis, while the other was analyzed using transmission electron microscopy. Data analysis was limited to fragments from patients with bacteria in the microbiological analysis.

RESULTS

Data analysis is based on samples obtained from 21 ulcers in 21 patients who had bacteria in their ulcer based on microbiologic analysis of a tissue sample. Most ulcers were open for 2 to 10 years, 57% (n = 12) were 16 cm2 or smaller, and the proportion of the wound bed covered by necrotic tissue coverage varied widely. Of the 21/44 patients (48%) with bacteria in their ulcers, only 3 patients had bacterial biofilm present in the transmission electron microscopy, corresponding to 7% of the 44 patients. Pseudomonas aeruginosa was the most frequent bacterium, identified in 10 fragments. The biofilm was not present on the surface but in a layer slightly below it. The detection of biofilms was not directly related to the duration of the ulcer. It was not possible to establish a correlation between the size of the lesion and the presence of these microorganisms due to the small sample size.

CONCLUSIONS

Our findings indicate that detecting biofilm in venous ulcers is challenging, as it does not uniformly occur throughout the wound bed, can occur at different depths, and is often not present on the wound surface. There is a need to develop studies that can contribute to the detection of biofilm in clinical practice.

Biofilm formation and antibiogram profile of bacteria from infected wounds in a general hospital in southern Ethiopia

Biofilm-producing bacteria associated with wound infections exhibit exceptional drug resistance, leading to an escalation in morbidity, worse clinical outcomes (including delay in the healing process), and an increase in health care cost, burdening the whole system. This study is an attempt to estimate the prevalence and the relationship between the biofilm-forming capacity and multi-drug resistance of wound bacterial isolates. The findings intended to help clinicians, healthcare providers and program planners and to formulate an evidence-based decision-making process, especially in resource-limited healthcare settings. This study was done to assess the prevalence of bacterial infections in wounds and the antibiogram and biofilm-forming capacity of those bacteria in patients with clinical signs and symptoms, attending a General Hospital in southern Ethiopia. A cross-sectional study was performed in Arba Minch General Hospital from June to November 2021. The study participants comprised 201 patients with clinically infected wounds. Demographic and clinical data were gathered via a structured questionnaire. Specimens from wounds were taken from each participant and inoculated onto a series of culture media, namely MacConkey agar, mannitol salt agar, and blood agar, and different species were identified using a number of biochemical tests. Antimicrobial susceptibility tests were performed by means of the Kirby-Bauer disc diffusion technique following the guidelines of the Clinical and Laboratory Standards Institute. A micro-titer plate method was employed to detect the extent of biofilm formation. Bivariable and multivariable logistic regression models were applied to analyse the association between dependent and independent variables, and P values ≤ 0.05 were considered as statistically significant. Data analyses were done with Statistical Package for the Social Sciences version 25. Out of the 201 clinically infected wounds, 165 were found culture-positive with an overall prevalence of 82% (95% CI: 75.9-86.9). In total, 188 bacteria were recovered; 53.1% of them were Gram-positive cocci. The often-isolated bacterial species were Staphylococcus aureus, 38.3% (n = 72), and Pseudomonas aeruginosa, 16.4% (n = 31). The Gram-positive isolates showed considerable resistance against penicillin, 70%, and somewhat strong resistance against tetracycline, 57.7%. Gram-negative isolates showed severe resistance to ampicillin, 80.68%. The overall multi-drug resistance (MDR) among isolates was 48.4%. Extended beta-lactamase (ESBL)-producing Gram-negatives and methicillin-resistant Staphylococcus aureus (MRSA) accounted for 49 and 41.67%, respectively; 62.2% of the isolates were biofilm formers and were correlated statistically with MDR, ESBL producers, and MRSA (P < 0.005). The extent of biofilm formation and the prevalence of MDR bacteria associated with infected wounds hint at a public health threat that needs immediate attention. Thus, a more balanced and comprehensive wound management approach and antimicrobial stewardship program are essential in the study setting.

Therapeutic Potential of Insect Defensin DLP4 Against Staphylococcus hyicus-Infected Piglet Exudative Epidermitis

Background/Objectives: The emergence of resistance to Staphylococcus hyicus (S. hyicus), the major cause of exudative epidermatitis (EE) in piglets, has led to the need for new antimicrobial agents. The study aimed to evaluate the potential efficacy of the insect defensin DLP4 against EE in piglets caused by clinically isolated S. hyicus ACCC 61734. Methods and Results: DLP4 showed strong antibacterial activity against S. hyicus ACCC 61734 (minimum inhibitory concentration, MIC: 0.92 μM, median effect concentration, EC50: 3.158 μM). DLP4 could effectively inhibit the formation of S. hyicus early biofilm with an inhibition rate of 95.10-98.34% and eradicate mature biofilm with a clearance rate of 82.09-86.41%, which was significantly superior to that of ceftriaxone sodium (CRO). Meanwhile, DLP4 could efficiently inhibit bacteria in early and mature biofilm, killing up to 95.3% of bacteria in early biofilm and 87.2-90.3% of bacteria in mature biofilm. The results showed that DLP4 could be effective in alleviating the clinical symptoms of EE by down-regulating the nuclear factor κB (NF-κB) signaling pathway, balancing cytokines, inhibiting bacterial proliferation, and reducing organ tissue damage. Conclusions: This study firstly demonstrated the potential efficacy of DLP4 against EE caused by S. hyicus ACCC 61734 infection in piglets, which may be used as an alternative to antibiotics in treating EE.

The chronic wound characterisation study and biobank: a study protocol for a prospective observational cohort investigation of bacterial community composition, inflammatory responses and wound-healing trajectories in non-healing wounds

INTRODUCTION

Chronic wounds affect 1%-2% of the global population, with rising incidence due to ageing and lifestyle-related diseases. Bacterial biofilms, found in 80% of chronic wounds, and scattered single-cell bacteria may hinder healing. Microbes are believed to negatively impact healing by exacerbating inflammation and host immune response.

METHODS AND ANALYSIS

The primary objective of the chronic wound characterisation (CWC) study is to investigate chronic wounds through a prospective observational cohort study exploring bacterial community composition, inflammatory responses and the influence of bacteria on wound-healing trajectories. The CWC study will be investigated through two cohorts: the predictive and in-depth.The predictive cohort includes patients with a chronic wound scheduled for mechanical debridement. The debrided material will be collected for dual RNA sequencing and 16s ribosomal RNA gene sequencing, as well as samples for microbial culturing and a photo to assess the wound. Clinical data is recorded, and healing and/or other clinical endpoints are established through medical records.The in-depth cohort includes and follows patients undergoing split-thickness skin grafting. Extensive sampling (ESwabs, biopsies, tape strips, debrided material and a sample of the skin graft) will be performed on surgery and patients will be seen at two follow-up visits. Samples will be analysed through culturing and next-generation sequencing methods. A biobank will be established comprising longitudinal clinical samples and clinical data.

ETHICS AND DISSEMINATION

The study has been approved by the board of health ethics, Capital Region of Denmark, under protocol number H-20032214. The study findings will be disseminated through peer-reviewed publications and showcased at both national and international conferences and meetings within the domains of microbiology, wound healing and infection.

Ultrasound-Mediated Antibiotic Delivery to In Vivo Biofilm Infections: A Review

Bacterial biofilms are a significant concern in various medical contexts due to their resilience to our immune system as well as antibiotic therapy. Biofilms often require surgical removal and frequently lead to recurrent or chronic infections. Therefore, there is an urgent need for improved strategies to treat biofilm infections. Ultrasound-mediated drug delivery is a technique that combines ultrasound application, often with the administration of acoustically-active agents, to enhance drug delivery to specific target tissues or cells within the body. This method involves using ultrasound waves to assist in the transportation or activation of medications, improving their penetration, distribution, and efficacy at the desired site. The advantages of ultrasound-mediated drug delivery include targeted and localized delivery, reduced systemic side effects, and improved efficacy of the drug at lower doses. This review scrutinizes recent advances in the application of ultrasound-mediated drug delivery for treating biofilm infections, focusing on in vivo studies. We examine the strengths and limitations of this technology in the context of wound infections, device-associated infections, lung infections and abscesses, and discuss current gaps in knowledge and clinical translation considerations.

Advances in ionic liquid-based antimicrobial wound healing platforms

Wound infections, marked by the proliferation of microorganisms at surgical sites, necessitate the development of innovative wound dressings with potent bactericidal properties to curb microbial growth and prevent bacterial infiltration. This study explores the recent strides in utilizing ionic liquid-based polymers as highly promising antimicrobial agents for advanced wound healing applications. Specifically, cationic polymers containing quaternary ammonium, imidazolium, guanidinium, pyridinium, triazolium, or phosphonium groups have emerged as exceptionally effective antimicrobial compounds. Their mechanism of action involves disrupting bacterial membranes, thereby preventing the development of resistance and minimizing toxicity to mammalian cells. This comprehensive review not only elucidates the intricate dynamics of the skin's immune response and the various stages of wound healing but also delves into the synthesis methodologies of ionic liquid-based polymers. By spotlighting the practical applications of antimicrobial wound dressings, particularly those incorporating ionic liquid-based materials, this review aims to lay the groundwork for future research endeavors in this burgeoning field. Through a nuanced examination of these advancements, this article seeks to contribute to the ongoing progress in developing cutting-edge wound healing platforms that can effectively address the challenges posed by microbial infections in surgical wounds.

Clinical efficacy and safety of a silver ion-releasing foam dressing on hard-to-heal wounds: a meta-analysis

OBJECTIVE

Delayed or stalled healing in open wounds can result from persisting chronic inflammation related to infection and/or persistent bacterial colonisation and biofilm. Treatment of hard-to-heal wounds focuses on debridement and exudate management, but also on infection prevention and control. Silver dressings have been evaluated in randomised clinical trials (RCTs); this meta-analysis evaluated the efficacy and safety of a silver ion-releasing foam dressing (Biatain Ag; Coloplast A/S, Denmark) to treat hard-to-heal wounds.

METHOD

Literature databases (PubMed and Cochrane Library) were searched for studies on silver ion-releasing foam dressings in the treatment of hard-to-heal wounds. Individual patient data from four RCTs were obtained and included in the meta-analysis.

RESULTS

Findings showed that treatment with the silver ion-releasing foam dressing was associated with a significantly higher relative reduction in wound area after four (least squares-mean difference (LS-MD): -12.55%, 95% confidence interval (CI): (-15.95, -9.16); p<0.01) and six weeks of treatment (LS-MD: -11.94%, 95%CI: (-17.21, -6.68); p<0.01) compared with controls. Significant benefits were also observed for time to disappearance of odour (hazard ratio: 1.61, 95%CI: (1.31, 1.98); p<0.01), relative reduction of exudate (LS-MD: -5.15, 95%CI: (-7.36, -2.94); p<0.01), proportion of patients with periwound erythema (relative risk (RR): 0.81, 95%CI: (0.69; 0.94); p<0.01), and less pain at dressing removal (LS-MD: -0.35, 95%CI: (-0.63, -0.06); p=0.02). No differences regarding safety outcomes were identified.

CONCLUSION

This meta-analysis has demonstrated beneficial outcomes and a good tolerability profile for silver ion-releasing foam dressings in the treatment of moderate-to-highly exuding wounds with delayed healing compared with control dressings.

Does the use of DACC-coated dressings improve clinical outcomes for hard to heal wounds: A systematic review

Reports of overuse and antimicrobial resistance have fuelled some clinicians to adopt alternative wound dressings termed to be non-medicated or non-antimicrobials, which still claim antimicrobial or antibacterial activity. In this PROSPERO-registered systematic review, we evaluated the in vivo clinical evidence for the effectiveness of DACC-coated dressings in chronic, hard to heal wound-related outcomes. The Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) Framework was adopted as the template in constructing this systematic review. The PICO format (Population [or patients], Intervention, Comparison [control], Outcome/s) was used to identify key clinical questions in determining patient outcomes under two domains (infection control and wound healing). A systematic search was performed in PubMed, OVID, Cochrane Library, clinical trial registries and data sources from independent committees. Abstracts of all studies were screened independently by two reviewers, with six further reviewers independently assessing records proceeding to full review. The authors rated the quality of evidence for each of the outcomes critical to decision making. After excluding duplicates, 748 records were screened from the databases, and 13 records were sought for full review. After full review, we excluded a further three records, leaving ten records for data extraction. Three records were narrative reviews, three systematic reviews, two prospective non-comparative before/after studies, one prospective head-to-head comparator cohort study and one retrospective head-to-head comparator cohort study. No RCTs or case versus control studies were identified. The overall quality of clinical evidence for the use of DACC-coated dressing to improve wound infection and wound healing outcomes was assessed as very low. There is an urgent unmet need to perform appropriately designed RCTs or case-control studies. The extracted data provide no clarity and have limited to no evidence to support that using a DACC-coated dressing improves wound infection or wound healing outcomes. Further, there is no evidence to suggest this therapy is either superior to standard of wound care or equivocal to topical antimicrobial agents in the management of infected hard to heal wounds.

Combinatorial Effects of Ursodeoxycholic Acid and Antibiotic in Combating Staphylococcus aureus Biofilm: The Roles of ROS and Virulence Factors

Staphylococcus aureus is a biofilm-forming bacterium responsible for various human infections, one particularly challenging to treat due to its antibiotic resistance. Biofilms can form on both soft tissues and medical devices, leading to persistent and hard-to-treat infections. Combining multiple antimicrobials is a potential approach to overcoming this resistance. This study explored the effects of ursodeoxycholic acid (UDCA) combined with the antibiotic ciprofloxacin against S. aureus biofilms, aiming to evaluate any synergistic effects. Results showed that UDCA and ciprofloxacin co-treatment significantly reduced biofilm formation and disrupted pre-formed biofilms more effectively than either agent alone (p < 0.01). The combination also displayed a slight synergistic effect, with a fractional inhibitory concentration of 0.65. Additionally, the treatment reduced the production of extracellular polymeric substances, increased reactive oxygen species production, decreased metabolic activity, altered cell membrane permeability, and lowered cell surface hydrophobicity in S. aureus. Furthermore, it diminished biofilm-associated pathogenic factors, including proteolytic activity and staphyloxanthin production. Overall, the UDCA-ciprofloxacin combination shows considerable promise as a strategy to combat infections related to staphylococcal biofilms, offering a potential solution to the healthcare challenges posed by antibiotic-resistant S. aureus.

Evaluation and Management of Pelvic Osteomyelitis in Stage IV Pressure Injuries: A Multidisciplinary Collaborative Approach

Managing pelvic osteomyelitis (POM) in the setting of stage IV pressure injuries requires multidisciplinary evaluation as well as patient and caregiver engagement and is complicated by the lack of high-evidence data to guide best practices. In this review, we describe our approach to pressure injury and POM evaluation and management through multidisciplinary collaboration and highlight areas of future research that are necessary to enhance patient outcomes, reduce healthcare costs, and improve the quality of life of those affected by POM.

Assessing Biofilm at the Bedside: Exploring Reliable Accessible Biofilm Detection Methods

INTRODUCTION

Biofilm is linked through a variety of mechanisms to the pathogenesis of chronic wounds. However, accurate biofilm detection is challenging, demanding highly specialized and technically complex methods rendering it unapplicable for most clinical settings. This study evaluated promising methods of bedside biofilm localization, fluorescence imaging of wound bacterial loads, and biofilm blotting by comparing their performance against validation scanning electron microscopy (SEM).

METHODS

In this clinical trial, 40 chronic hard-to-heal wounds underwent the following assessments: (1) clinical signs of biofilm (CSB), (2) biofilm blotting, (3) fluorescence imaging for localizing bacterial loads, wound scraping taken for (4) SEM to confirm matrix encased bacteria (biofilm), and (5) PCR (Polymerase Chain Reaction) and NGS (Next Generation Sequencing) to determine absolute bacterial load and species present. We used a combination of SEM and PCR microbiology to calculate the diagnostic accuracy measures of the CSB, biofilm blotting assay, and fluorescence imaging.

RESULTS

Study data demonstrate that 62.5% of wounds were identified as biofilm-positive based on SEM and microbiological assessment. By employing this method to determine the gold truth, and thus calculate accuracy measures for all methods, fluorescence imaging demonstrated superior sensitivity (84%) and accuracy (63%) compared to CSB (sensitivity 44% and accuracy 43%) and biofilm blotting (sensitivity 24% and accuracy 40%). Biofilm blotting exhibited the highest specificity (64%), albeit with lower sensitivity and accuracy. Using SEM alone as the validation method slightly altered the results, but all trends held constant.

DISCUSSION

This trial provides the first comparative assessment of bedside methods for wound biofilm detection. We report the diagnostic accuracy measures of these more feasibly implementable methods versus laboratory-based SEM. Fluorescence imaging showed the greatest number of true positives (highest sensitivity), which is clinically relevant and provides assurance that no pathogenic bacteria will be missed. It effectively alerted regions of biofilm at the point-of-care with greater accuracy than standard clinical assessment (CSB) or biofilm blotting paper, providing actionable information that will likely translate into enhanced therapeutic approaches and better patient outcomes.

Impact of continuous topical oxygen therapy on biofilm gene expression in a porcine tissue model

OBJECTIVE

The effect of continuous topical oxygen therapy (cTOT) on Pseudomonas aeruginosa biofilm gene transcription profiles following inoculation onto porcine skin, using a customised molecular assay was determined.

METHOD

Sterilised porcine skin explants were inoculated with Pseudomonas aeruginosa in triplicate: 0 hours as negative control; 24 hours cTOT device on; 24 hours cTOT device off. The oxygen delivery system of the cTOT device was applied to the inoculated tissue and covered with a semi-occlusive dressing. All samples were incubated at 37±2°C for 24 hours, with the 0 hours negative control inoculated porcine skin samples recovered immediately. Planktonic suspensions and porcine skin biopsy samples were taken at 0 hours and 24 hours. Samples were processed and quantifiably assessed using gene specific reverse transcription-quantitative polymerase chain reaction assays for a panel of eight Pseudomonas aeruginosa genes (16S, pelA, pslA, rsaL, pcrV, pscQ, acpP, cbrA) associated with biofilm formation, quorum sensing, protein secretion/translocation and metabolism.

RESULTS

Transcriptional upregulation of pelA, pcrV and acpP, responsible for intracellular adhesion, needletip protein production for type-3 secretion systems and fatty acid synthesis during proliferation, respectively, was observed when the cTOT device was switched on compared to when the device was switched off. Data suggest increased metabolic activity within bacterial cells following cTOT treatment.

CONCLUSION

cTOT is an adjunctive therapy that supports faster healing and pain reduction in non-healing hypoxic wounds. Oxygen has previously been shown to increase susceptibility of biofilms to antibiotics through enhancing metabolism. Observed gene expression changes highlighted the impact of cTOT on biofilms, potentially influencing antimicrobial treatment success in wounds. Further in vitro and clinical investigations are warranted.

In vitro models for studying implant-associated biofilms - A review from the perspective of bioengineering 3D microenvironments

Biofilm research has grown exponentially over the last decades, arguably due to their contribution to hospital acquired infections when they form on foreign body surfaces such as catheters and implants. Yet, translation of the knowledge acquired in the laboratory to the clinic has been slow and/or often it is not attempted by research teams to walk the talk of what is defined as 'bench to bedside'. We therefore reviewed the biofilm literature to better understand this gap. Our search revealed substantial development with respect to adapting surfaces and media used in models to mimic the clinical settings, however many of the in vitro models were too simplistic, often discounting the composition and properties of the host microenvironment and overlooking the biofilm-implant-host interactions. Failure to capture the physiological growth conditions of biofilms in vivo results in major differences between lab-grown- and clinically-relevant biofilms, particularly with respect to phenotypic profiles, virulence, and antimicrobial resistance, and they essentially impede bench-to-bedside translatability. In this review, we describe the complexity of the biological processes at the biofilm-implant-host interfaces, discuss the prerequisite for the development and characterization of biofilm models that better mimic the clinical scenario, and propose an interdisciplinary outlook of how to bioengineer biofilms in vitro by converging tissue engineering concepts and tools.

The use of PICO™ single-use negative pressure wound therapy in the community settings

The prevalence and incidence of wounds is predicted to rise due to an ageing population, that is also likely to have an increasing number of comorbidities (Dowsett et al, 2017). This trend will invariably result in increased costs to the NHS. The estimated annual cost of wound management in 2017/2018 was £8.3 billion. The cost of managing 70% of wounds which healed was £2.7 billion while it cost £5.6 billion managing only 30% of unhealed wounds (Guest et al, 2020). In view of these figures, it is important that health professionals (HPs) recognise wounds that are not progressing to healing at an early stage and implement all available treatment modalities to ensure that the wound does not become non-healing or stalled. Therefore, this article defines non-healing wounds, how to identify wounds at risk of becoming non-healing and the timely implementation of advanced treatment modalities, such as single use negative pressure wound therapy (sNPWT).

Escherichia coli exopolysaccharides disrupt Pseudomonas aeruginosa biofilm and increase its antibiotic susceptibility

Pseudomonas aeruginosa (P. aeruginosa) is a major pathogen that causes infectious diseases. It has high tendency to form biofilms, resulting in the failure of traditional antibiotic therapies. Inspired by the phenomenon that co-culture of Escherichia coli (E. coli) and P. aeruginosa leads to a biofilm reduction, we reveal that E. coli exopolysaccharides (EPS) can disrupt P. aeruginosa biofilm and increase its antibiotic susceptibility. The results show that E. coli EPS effectively inhibit biofilm formation and disrupt mature biofilms in P. aeruginosa, Staphylococcus aureus, and E. coli itself. The maximal inhibition and disruption rates against P. aeruginosa biofilm are 40 % and 47 %, respectively. Based on the biofilm-disrupting ability of E. coli EPS, we develop an E. coli EPS/antibiotic combining strategy for the treatment of P. aeruginosa biofilms. The combination with E. coli EPS increases the antibacterial efficiency of tobramycin against P. aeruginosa biofilms in vitro and in vivo. This study provides a promising strategy for treating biofilm infections. STATEMENT OF SIGNIFICANCE: Biofilm formation is a leading cause of chronic infections. It blocks antibiotics, increases antibiotic-tolerance, and aids in immune evasion, thus representing a great challenge in clinic. This study proposes a promising approach to combat pathogenic Pseudomonas aeruginosa (P. aeruginosa) biofilms by combining Escherichia coli exopolysaccharides with antibiotics. This strategy shows high efficiency in different P. aeruginosa stains, including two laboratory strains, PAO1 and ATCC 10145, as well as a clinically acquired carbapenem-resistant strain. In addition, in vivo experiments have shown that this approach is effective against implanted P. aeruginosa biofilms and can prevent systemic inflammation in mice. This strategy offers new possibilities to address the clinical failure of conventional antibiotic therapies for microbial biofilms.

Assessment of the Antibiofilm Performance of Silver-Containing Wound Dressings: A Dual-Species Biofilm Model

Background It is commonly accepted that microorganisms found within hard-to-heal wounds are present in biofilm form. Biofilms are often polymicrobial in nature, which increases their virulence and tolerance to antimicrobial agents. The aim of this study was to compare the antibiofilm activity of silver-containing antimicrobial wound dressings in a dual-species simulated wound biofilm model. Materials and methods Four silver-containing wound dressings were evaluated in vitro: Aquacel® Ag+ Extra™ dressing, KerraContact® Ag dressing, Durafiber* Ag dressing, and UrgoClean Ag dressing. Each dressing was applied to a simulated wound assembly containing biofilm-gauze inoculated with Klebsiella pneumoniae and methicillin-resistant Staphylococcus aureus (MRSA). Each biofilm-inoculated gauze was incubated at 35±3ºC for 6, 24, 48 and 72 hours. Enumeration of surviving biofilm bacteria at each time point was performed in triplicate for each test dressing and its equivalent control. Results Aquacel® Ag+ Extra™ dressing was observed to reduce the biofilm population within 24 hours with a >4 log10 kill observed for K. pneumoniae and >6 log10 for MRSA from an initial biofilm challenge of 4.16×109 CFU/mL. This kill rate was sustained for the duration of the challenge period, with Aquacel® Ag+ Extra™ dressing reducing the biofilm population to non-detectable levels (<30 Colony Forming Units (CFU) per test) by 72 hours for K. pneumoniae and by 48 hours for MRSA. KerraContact® Ag dressing demonstrated an initial reduction at 6 hours of ~2 log10 in both K. pneumoniae and MRSA. Durafiber* Ag dressing exhibited a slight, gradual reduction in biofilm population over the course of the test period, reducing each challenge organism by ~2.5 log10 by 72 hours. UrgoClean Ag was shown to have little to no impact on the dual-species biofilm with levels remaining similar or greater than that recovered prior to dressing application. The no-dressing biofilm-colonised gauze control demonstrated that the biofilm bacteria remained viable throughout the test period and species population proportionality was maintained. Conclusion Using a dual-species simulated wound biofilm model comprising the pathogens K. pneumoniae and MRSA, Aquacel® Ag+ Extra™ dressing demonstrated significantly greater antibiofilm activity than the other silver-containing dressings. The enhanced antibiofilm activity of Aquacel® Ag+ Extra™ dressing in this study may be attributed to the additional antibiofilm agents, ethylenediaminetetraacetic acid and benzethonium chloride, contained within the dressing.

The Profile of Bacterial Infections in a Burn Unit during and after the COVID-19 Pandemic Period

Infections represent a major complication for burn-injured patients. The aim of this study was to highlight the changes in the incidence and antimicrobial resistance of bacterial strains isolated from burn patients, at the end of the COVID-19 pandemic, in relation to the antibiotics used during the pandemic. A comparative analysis of the demographic data and the microorganisms identified in the clinical samples of two groups of burn patients admitted to a university hospital in Romania was carried out. The first group consisted of 48 patients and the second of 69 patients, hospitalized in January-August 2020 and 2023, respectively. The bacterial species with the highest incidence were S. aureus, A. baumannii, Pseudomonas spp. The significant changes between 2023 and 2020 are reflected in the increase in the frequency of non-fermentative Gram-negative bacteria, especially S. maltophilia, and the increase in antimicrobial resistance of Pseudomonas and Klebsiella spp. Klebsiella spp. did not change in frequency (7%), but there was a significant increase in the incidence of K. pneumoniae strains with pan-drug resistant behaviour to antibiotics (40%), including colistin. The phenomenon can be explained by the selection of specimens carrying multiple resistance genes, as a result of antibiotic treatment during the COVID-19 period. The post-pandemic antimicrobial resistance detected in burn patients indicates the need for permanent surveillance of the resistance trends, primarily due to the limited therapeutic options available for these patients.

The rat as an animal model in chronic wound research: An update

The increasing global prevalence of chronic wounds underscores the growing importance of developing effective animal models for their study. This review offers a critical evaluation of the strengths and limitations of rat models frequently employed in chronic wound research and proposes potential improvements. It explores these models in the context of key comorbidities, including diabetes, venous and arterial insufficiency, pressure-induced blood flow obstruction, and infections. Additionally, the review examines important wound factors including age, sex, smoking, and the impact of anesthetic and analgesic drugs, acknowledging their substantial effects on research outcomes. A thorough understanding of these variables is crucial for refining animal models and can provide valuable insights for future research endeavors.

The wound microbiota: microbial mechanisms of impaired wound healing and infection

The skin barrier protects the human body from invasion by exogenous and pathogenic microorganisms. A breach in this barrier exposes the underlying tissue to microbial contamination, which can lead to infection, delayed healing, and further loss of tissue and organ integrity. Delayed wound healing and chronic wounds are associated with comorbidities, including diabetes, advanced age, immunosuppression and autoimmune disease. The wound microbiota can influence each stage of the multi-factorial repair process and influence the likelihood of an infection. Pathogens that commonly infect wounds, such as Staphylococcus aureus and Pseudomonas aeruginosa, express specialized virulence factors that facilitate adherence and invasion. Biofilm formation and other polymicrobial interactions contribute to host immunity evasion and resistance to antimicrobial therapies. Anaerobic organisms, fungal and viral pathogens, and emerging drug-resistant microorganisms present unique challenges for diagnosis and therapy. In this Review, we explore the current understanding of how microorganisms present in wounds impact the process of skin repair and lead to infection through their actions on the host and the other microbial wound inhabitants.

Chia seed-mediated fabrication of ZnO/Ag/Ag2O nanocomposites: structural, antioxidant, anticancer, and wound healing studies

Plant extract-mediated fabrication of metal nanocomposites is used in cell proliferation inhibition and topical wound treatment, demonstrating significant effectiveness. Salvia hispanica L. (chia) seed extract (CE) is used as the reaction medium for the green fabrication of ecofriendly ZnO(CE) nanoparticles (NPs) and Ag/Ag2O(CE) and ZnO/Ag/Ag2O(CE) nanocomposites. The resultant nanoparticles and nanocomposite materials were characterized using UV-visible, Fourier-transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), X-ray diffraction (XRD), and energy-dispersive X-ray (EDX) techniques. In the context of antioxidant studies, ZnO/Ag/Ag2O(CE) exhibited 57% reducing power and 86% 2,2, diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging. All three materials showed strong antibacterial activity against Staphylococcus aureus (S. aureus), Escherichia coli (E.coli), and Bacillus subtilis (B. subtilis) bacterial strains. Additionally, ZnO(CE), Ag/Ag2O(CE), and ZnO/Ag/Ag2O(CE) also revealed 64.47%, 42.56%, and 75.27% in vitro Michigan Cancer Foundation-7 (MCF7) cancer cell line inhibition, respectively, at a concentration of 100 μg/mL. Selectively, the most effective composite material, ZnO/Ag/Ag2O(CE), was used to evaluate in vivo wound healing potential in rat models. The study revealed 96% wound closure in 10 days, which was quite rapid healing compared to wound healing using clinically available ointment. Therefore, in conclusion, the ZnO/Ag/Ag2O(CE) nanocomposite material could be considered for further testing and formulation as a good anticancer and wound healing agent.