Chronic wounds are lesions that do not heal for an extended period of time despite standard treatment. A key contributor to this persistent problem is a nefarious substance known as biofilm. Believed to occur in approximately 60% of chronic wounds, biofilm is a literal barrier of microorganisms that makes wound healing all the more difficult.
What Are Biofilms?
Biofilm is a membrane-like tissue with distinct layers and channels created by a pathogen, much like a protective enclosure that can grow and thrive. It is generally made of three components:
- Proteins: Both structural and enzymatic proteins that help form the framework of the biofilm.
- Polysaccharides: Sugars responsible for the biofilm’s sticky, gel-like consistency. They also contribute to its stability and ability to adhere to surfaces.
- Nucleic Acids: DNAs and RNAs that maintain biofilm structure and enable genetic exchange among microorganisms.
While biofilms can form on various living tissues, they most commonly occur in open wound beds, i.e., the exposed tissue service in a chronic wound. Firstly, their embedded nature makes them difficult to detect within the wound’s tissue. Secondly, they are even harder to eradicate as their composition shields the microorganisms within from both the immune system and antimicrobial treatments.
The Formation of Biofilms
In a chronic wound, biofilm forms in several stages:
- Initial Attachment: The pathogen adheres to the wound bed surface using tiny, hair-like projections known as pili or fimbriae.
- Microcolony Formation: They proliferate to form small clusters known as microcolonies. During this stage, they also begin to secrete gel-like substances that form the foundation of the biofilm.
- Mature Biofilm Development: As these microorganisms continue to secrete substances, they form the complex, three-dimensional structure known as the biofilm.
- Dispersion: The final stage sees cells from the mature biofilm spread into the surrounding environment, either as individual cells or as small clusters. Regardless, this spread facilitates further infection, potentially leading to more widespread complications.
Complications Caused by Biofilm
When biofilm forms within a lesion, it drastically impedes healing in a number of ways:
- Blocks Immune Response: The biofilm acts as a shield that is nearly impossible for immune cells to penetrate. Without the ability to reach and effectively destroy the microorganisms making the biofilm, the immune response is severely compromised, allowing the biofilm to persist and thrive.
- Prolonged Inflammation: Despite its ineffectiveness, the immune system continues to react to the biofilm. This leads to chronic inflammation, which damages the surrounding tissues. Not only does it cause more tissue breakdown, but it also impairs normal repair processes.
- Antibiotic Resistance: To complicate matters, biofilms are often highly resistant to antibiotics. This is due to its dense matrix, which prevents antibiotics from penetrating. At the same time, the biofilm secretes enzymes that neutralize antimicrobial agents. Consequently, the infection persists, making conventional treatments ineffective.
The combined effect of all these complications completely disrupts normal wound-healing pathways. As a result, the lesion can no longer progress through the phases of healing. It is now a chronic wound that demands more invasive interventions in order to mend itself.
How to Diagnose Biofilm in Chronic Wounds
Identifying biofilm within a chronic wound can be challenging because it is not always apparent. Traditional wound cultures usually fail to identify biofilm-related infections because these matrices often contain microorganisms in lower concentrations than those found in most acute infections.
The most widespread method is, therefore, a wound biopsy. This procedure takes a sample of the wound tissue for histological examination that uses staining techniques to reveal the presence of biofilms. Other diagnostics tools include polymerase chain reaction (PCR) and sequencing, which can identify specific microbial DNA. This can help detect biofilm-forming microorganisms even when present in low concentrations. Laboratory assays, such as the crystal violet assay, can also help quantify biofilm biomass and determine the extent of its formation.
Treating Biofilm-Related Chronic Wounds
When treating chronic wounds complicated by biofilm, healthcare professionals take a multifaceted approach that includes several interventions. Key strategies are listed below.
Wound Debridement
Wound debridement involves the physical removal of biofilm and necrotic tissue through:
- Sharp Debridement: Surgical instruments, such as scalpels or scissors, precisely remove devitalized tissue and biofilm. This method is highly effective for removing thick, adherent biofilms
- Enzymatic Debridement: Topical agents containing enzymes, such as proteases, dissolve the biofilm matrix. This method is best suited for a more extensive spread or those not amenable to sharp debridement.
- Ultrasound-Assisted Debridement: The least invasive, this technique employs high-frequency sound waves to create micro-cavitation bubbles within the wound bed. The energy from these bubbles helps dislodge and remove biofilm and necrotic tissue. While gentle, ultrasound-assisted debridement is especially effective for delicate or hard-to-reach areas. It also promotes wound healing by enhancing blood flow and tissue regeneration – an added benefit.
Antibiotic Therapy
Although biofilms often resist many antibiotics, these drugs combined with other therapeutic modalities can prove effective. For example, antibiotics may be delivered directly to the wound site after debridement.
It is important to note that the choice of antibiotics is based on the specific pathogens identified in the wound culture. While broad-spectrum antibiotics can be used initially, narrower-spectrum antibiotics are better suited to target those specific bacteria once they are identified.
Advanced Wound Care
Advanced wound care covers every aspect of wound treatment, from initial assessment and debridement to ongoing monitoring. It is a holistic approach that ensures every contributor impeding healing is dealt with.
For biofilm-affected wounds, advanced wound care also uses biofilm-disrupting agents such as enzymes (e.g., DNase) and surfactants to break down its matrix. This exposes the microorganisms inside and makes them more susceptible to treatment.
Wound care also makes use of dressings with antimicrobial properties, which are designed to provide a sustained release of agents that offer continuous protection against biofilm-related infections. Among these are silver-based dressings, which gradually release silver ions to prevent the spread of infections.
Hyperbaric Oxygen Therapy (HBOT)
HBOT is a cutting-edge treatment that lets patients breathe pure oxygen in a pressurized chamber. This technique results in much higher concentrations of oxygen being delivered to the body’s tissues, which in turn supports healthy tissue regeneration and accelerates wound healing.
More importantly, high levels of oxygen can penetrate this matrix, creating an environment that is less conducive to biofilm stability. This disrupts the action of the biofilm-making microorganisms, making them more susceptible to antibiotics and the body’s immune responses.
Elevated oxygen concentrations also have a bactericidal effect, directly killing certain types of bacteria and inhibiting the growth of others. This enhanced antimicrobial environment can significantly reduce the bioburden in chronic wounds, helping to control and prevent infections. Additionally, increased oxygen levels boost the effectiveness of antibiotics, making them more potent against biofilm-protected pathogens.
Experience Advance Wound Care with Vayu
Biofilms represent a significant challenge in the management of chronic wounds. However, through a multifaceted approach that includes debridement, targeted antibiotic therapy, advanced wound care, and HBOT, these persistent infections can be eliminated effectively.
Take the first step towards better wound healing today. Contact Vayu Advanced Wound And Hyperbaric Clinic to learn more about our comprehensive wound care solutions and how we can aid you or your loved ones in achieving optimal healing. Visit our website or call us now to schedule a consultation.