Comparing methods of debridement for removing biofilm in hard-to-heal wounds

Mechanical properties of Staphylococcus aureus and Pseudomonas aeruginosa dual-species biofilms grown in chronic wound-based models

Wound infections become chronic due to biofilm formation by pathogenic bacteria; two such pathogens are Staphylococcus aureus and Pseudomonas aeruginosa. These bacteria are known to form polymicrobial biofilms in wounds, which exhibit increased colonization rates, enhanced chronicity, and greater resistance to treatment. Previously, the impacts of a wound bed environment on the mechanical properties of P. aeruginosa biofilms have been explored, and in this work the role of a wound bed environment in the viscoelasticity and microstructure of polymicrobial biofilms is characterized. We hypothesize that common wound bed proteins mediate interactions between S. aureus and P. aeruginosa to enable the formation of more elastic and stiff biofilms. Growth media with varying protein content as well as additional collagen, a protein associated with a wound extracellular matrix, were utilized to test our hypothesis. Microrheology indicates that both P. aeruginosa and S. aureus form relatively stiffer single-species biofilms in a wound environment with collagen. S. aureus produced stiffer biofilms in the presence of collagen, regardless of other wound proteins, likely due to its interactions with collagen. When both species were grown together in wound-like media, synergistic effects led to stiffer dual-species biofilms compared to their single-species forms. Under all growth conditions, collagen significantly contributed to stiffening P. aeruginosa/S. aureus dual-species biofilms, suggesting that it mediates complex interspecies interactions. High-resolution imaging and analysis revealed that collagen also influenced the microstructures of P. aeruginosa/S. aureus dual-species biofilms. In media containing wound proteins and collagen, S. aureus clusters were larger and exhibited more complex shapes. These results indicate that the wound bed environment not only provides improved antibacterial resistance due to cooperative interactions, but also improved mechanical protection, which impact common treatment methods like debridement.

Advancement of Nanomaterials- and Biomaterials-Based Technologies for Wound Healing and Tissue Regenerative Applications

Patients and healthcare systems face significant social and financial challenges due to the increasing number of individuals with chronic external and internal wounds that fail to heal. The complexity of the healing process remains a serious health concern, despite the effectiveness of conventional wound dressings in promoting healing. Recent advancements in materials science and fabrication techniques have led to the development of innovative dressings that enhance wound healing. To further expedite the healing process, novel approaches such as nanoparticles, 3D-printed wound dressings, and biomolecule-infused dressings have emerged, along with cell-based methods. Additionally, gene therapy technologies are being harnessed to generate stem cell derivatives that are more functional, selective, and responsive than their natural counterparts. This review highlights the significant potential of biomaterials, nanoparticles, 3D bioprinting, and gene- and cell-based therapies in wound healing. However, it also underscores the necessity for further research to address the existing challenges and integrate these strategies into standard clinical practice.

Biofilm Dispersal and Wound Infection Clearance With Preclinical Debridement Agents

Biofilms complicate wound care by causing recurrent infections that are often resistant to debridement and are highly antibiotic-tolerant. We investigated whether the addition of a biofilm dispersal agent could improve the efficacy of debridement. The previous studies have indicated that a glycoside hydrolase cocktail of alpha-amylase and cellulase can act as a potent biofilm dispersal agent. With in vitro and ex vivo Pseudomonas aeruginosa biofilm models, we compared glycoside hydrolases against other, clinically relevant, enzymatic debridement agents (papain, bromelain, and collagenase). Glycoside hydrolase biofilm dispersal was dose-dependent. However, at doses of 1% or above, glycoside hydrolases outperformed, or were comparable, to other enzymatic debridement agents. With our in vivo surgical wound infection model, we evaluated biofilm dispersal using infection dissemination as a proxy. We found that sharp debridement followed by multiple glycoside hydrolase treatments enhanced biofilm dispersal. Furthermore, a single dose of glycoside hydrolase in combination with debridement decreased infection load in acute wounds. Similarly, when we treated established 5-day-old infections, we saw a decrease in infection load and no infection dissemination. Overall, our data suggest that debridement enhances the efficacy of a topical antibiotic ointment, allowing for greater infection clearance.

Clinical performance and safety of a debridement pad with abrasive and non-abrasive fibres

BACKGROUND

Debridement is key to removing devitalised tissue, debris and biofilm as part of wound-bed preparation. Unlike many other methods of debridement, mechanical debridement with a pad is effective enough to be used independently without an adjunctive method of debridement, while being more accessible than other standalone options.

OBJECTIVE

To explore the clinical performance and safety of a debridement pad with both abrasive and non-abrasive surfaces in daily clinical practice.

METHODS

This was a prospective, non-controlled, non-randomised, single-arm, open-label, multicentred observational evaluation. Inclusion criteria were wounds >4 cm2 covered with at least 30% debris, necrotic tissue or slough in patients aged ≥18 years. The treatment protocol comprised a single application of the debridement pad. The primary outcome measure was the amount of necrotic tissue, slough or debris in the wound bed. Secondary outcomes included the appearance of the wound bed, edges and periwound skin; self-reported pain scores; foreseeable negative impacts; and clinician satisfaction.

RESULTS

A total of 62 participants with a variety of wound types were included in the analysis. Most wounds (87%) had been present for over 3 months and had high or moderate exudate levels (90%). A significant reduction was observed in all three parameters: necrotic tissue (p=0.043), slough (p<0.001) and debris (p<0.001). Necrotic tissue, slough and debris showed mean relative reductions of 40%, 72% and 40%, respectively. Of participants, 84% did not experience an increase in pain during the debridement procedure.

CONCLUSION

This clinical real-world data shows the debridement pad to be an effective and well-tolerated device for debridement and wound bed preparation.

Multifunctional antibacterial hydrogels for chronic wound management

Chronic wounds have gradually evolved into a global health challenge, comprising long-term non-healing wounds, local tissue necrosis, and even amputation in severe cases. Accordingly, chronic wounds place a considerable psychological and economic burden on patients and society. Chronic wounds have multifaceted pathogenesis involving excessive inflammation, insufficient angiogenesis, and elevated reactive oxygen species levels, with bacterial infection playing a crucial role. Hydrogels, renowned for their excellent biocompatibility, moisture retention, swelling properties, and oxygen permeability, have emerged as promising wound repair dressings. However, hydrogels with singular functions fall short of addressing the complex requirements associated with chronic wound healing. Hence, current research emphasises the development of multifunctional antibacterial hydrogels. This article reviews chronic wound characteristics and the properties and classification of antibacterial hydrogels, as well as their potential application in chronic wound management.

Topical desiccating agent (DEBRICHEM): an accessible debridement option for removing biofilm in hard-to-heal wounds

It is now assumed that all hard-to-heal wounds contain biofilm. Debridement plays a key role in wound-bed preparation, as it can remove biofilm along with the devitalised tissue, potentially leaving a clean wound bed that is more likely to progress towards healing. The gold standard methods of debridement (surgical and sharp) are the least used, as they require specialist training and are often not readily available at the point of need. Most other methods can be used by generalists but are slower. They all need regular applications. The topical desiccating agent DEBRICHEM is an innovative alternative, as it is fast, effective and can be used in all clinical settings, as well as typically requiring only a single use. This article describes best practice for achieving optimal outcomes with its use.

Strategies for combating antibiotic resistance in bacterial biofilms

Biofilms, which are complexes of microorganisms that adhere to surfaces and secrete protective extracellular matrices, wield substantial influence across diverse domains such as medicine, industry, and environmental science. Despite ongoing challenges posed by biofilms in clinical medicine, research in this field remains dynamic and indeterminate. This article provides a contemporary assessment of biofilms and their treatment, with a focus on recent advances, to chronicle the evolving landscape of biofilm research.

Nanomedicine against biofilm infections: A roadmap of challenges and limitations

Microbial biofilms are complex three-dimensional structures where sessile microbes are embedded in a polymeric extracellular matrix. Their resistance toward the host immune system as well as to a diverse range of antimicrobial treatments poses a serious health and development threat, being in the top 10 global public health threats declared by the World Health Organization. In an effort to combat biofilm-related microbial infections, several strategies have been developed to independently eliminate biofilms or to complement conventional antibiotic therapies. However, their limitations leave room for other treatment alternatives, where the application of nanotechnology to biofilm eradication has gained significant relevance in recent years. Their small size, penetration efficiency, and the design flexibility that they present makes them a promising alternative for biofilm infection treatment, although they also present set-backs. This review aims to describe the main possibilities and limitations of nanomedicine against biofilms, while covering the main aspects of biofilm formation and study, and the current therapies for biofilm treatment. This article is categorized under: Therapeutic Approaches and Drug Discovery > Nanomedicine for Infectious Disease Toxicology and Regulatory Issues in Nanomedicine > Toxicology of Nanomaterials Toxicology and Regulatory Issues in Nanomedicine > Regulatory and Policy Issues in Nanomedicine.