Antifungal Peptide Biofilm Disruption in Chronic Wound Care

Chronic wounds that fail to close within the expected trajectory often harbor biofilms. While bacterial biofilms receive most of the attention in wound care, fungal biofilms are increasingly documented in diabetic foot ulcers, lower-extremity wounds, and moist, macerated tissue. Candida species and other opportunistic fungi can form biofilms that resist conventional antifungals and antibiotics, sustain low-grade inflammation, and delay epithelial advancement. A growing body of research is examining antimicrobial peptides (AMPs) as a mechanistically distinct way to disrupt fungal biofilms rather than merely suppressing planktonic growth.

The Biofilm Problem in Chronic Wounds

Fungal biofilms are structured communities encased in extracellular polymeric substances (EPS). In that state, fungi tolerate concentrations of antifungal agents that would kill free-floating cells. Candida albicans, for example, can transition between yeast and hyphal forms inside a biofilm, and the hyphal phase is associated with tissue invasion and persistent inflammation. Mixed bacterial-fungal biofilms are especially common in chronic wounds, where bacterial species can stabilize the fungal matrix and fungi can increase bacterial tolerance to antibiotics.

The clinical takeaway is familiar to any wound center: a wound that looks clean but refuses to close may be carrying a biofilm burden that standard culture-based therapy does not fully address. Debridement and topical antiseptics remain first-line, but the search for biofilm-active adjuncts has led investigators to antimicrobial peptides.

How Antifungal Peptides Disrupt Biofilms

Antifungal peptides are short, typically cationic, amphipathic molecules that interact directly with microbial membranes. Unlike receptor-targeted drugs, they do not depend on a single fungal enzyme or pathway. This multitarget mode of action is the central reason they attract interest for biofilm disruption: an organism cannot easily counteract simultaneous damage to the membrane, cell wall, and biofilm matrix.

One representative example is P19, a tryptophan center symmetrical short peptide (sequence RRFSFWFSFRR-NH2) evaluated by Chou et al. P19 bound to lipopolysaccharides, lipoteichoic acids, and fungal plasma membrane phospholipids including phosphatidylinositol, phosphatidylserine, cardiolipin, and phosphatidylglycerol. The mechanism was not receptor recognition but competitive interaction with the membrane, and the peptide inhibited Candida albicans biofilm formation while showing lower potential for resistance selection than fluconazole and amphotericin B.

Another example is Glycine max antimicrobial peptide (GmAMP), identified by Cai et al. through AI modeling. Against fluconazole-resistant Candida tropicalis, GmAMP had a minimum inhibitory concentration (MIC) of 25 µM and was fungicidal at 100 µM within 2 hours. It inhibited biofilm formation by 88.32%, eradicated mature biofilm by 58.28%, prevented yeast-to-hypha transition, and caused membrane depolarization, permeabilization, and intracellular reactive oxygen species accumulation. In a Galleria mellonella infection model, GmAMP improved survival to 75% and reduced fungal burden by approximately 1.0 × 10^2 CFU per larva.

These studies illustrate three recurring mechanisms that matter for wound care: direct membrane disruption, inhibition of morphological transition, and physical reduction of established biofilm biomass.

Evidence Across Priority Fungal Pathogens

The peptide approach is not limited to Candida albicans. Several recent studies have examined AMPs against fungi that are difficult to manage in immunocompromised or chronically ill patients:

• CLEC3A-derived peptides showed broad-spectrum activity against Candida auris and other clinically relevant pathogens.
• A urease-derived peptide targeted the fungal cell wall and was evaluated as a potential antifungal agent against Candida species.
• The peptide SP1 damaged the polysaccharide capsule of Cryptococcus neoformans and enhanced macrophage phagocytosis.
• DvAMP was reported as a promising antimicrobial peptide against Cryptococcus neoformans.
• Broader reviews have repositioned AMPs against WHO-priority fungi and outlined design strategies for biofilm disruption.

All of this work remains preclinical or early translational. No peptide described here has an established chronic wound indication, dosing regimen, or CMS reimbursement code. The value for clinicians today is mechanistic: it confirms that biofilm disruption is a realistic therapeutic goal, and that peptides can achieve it through paths that differ from azoles and polyenes.

Protocol Considerations in the Wound Center

Until human wound trials define the role of antifungal peptides, the practical application is to integrate the biofilm concept into existing protocols. That means:

• Sharp debridement first. Peptides and topicals cannot reach a biofilm buried under thick necrotic tissue or hyperkeratotic rim.
• Culture with suspicion of mixed infection. Standard bacterial cultures may miss Candida or other fungi. Request fungal culture when a wound is indolent, malodorous, or macerated.
• Moisture balance. Excess moisture favors yeast proliferation; drying agents may help in intertriginous areas, while maintaining a moist wound bed on the wound bed itself.
• Offloading and glycemic control. Biofilm reformation is driven by pressure, ischemia, and glucose-driven immunosuppression.
• Adjunct selection. Advanced wound biologics such as amniotic membrane allografts are intended to support a physiologic wound environment. They are not antifungal peptides, but they fit into a broader strategy of reducing biofilm-friendly stagnation and promoting organized healing.

Antifungal Peptides vs. Conventional Agents

Key Takeaways