Antimicrobial Peptides in Wound Care

Peptide-Based Wound Dressings

3,200+ AMPs identified

Over 3,200 antimicrobial peptides have been cataloged from organisms across every branch of life, and a growing number are entering wound care research.

Mangoni et al., Experimental Dermatology, 2016

Mangoni et al., Experimental Dermatology, 2016

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Wound infection remains the single largest barrier to healing. Chronic wounds affect an estimated 2.5% of the U.S. population and cost the healthcare system over $25 billion annually.^[1] Conventional antibiotics are losing ground to resistant pathogens, and the wound environment degrades many drugs before they reach their targets. Antimicrobial peptides (AMPs), molecules that evolved over hundreds of millions of years as the immune system's first responders, represent a fundamentally different approach. For a broader look at how peptides are reshaping wound treatment, see our guide to peptide-based wound dressings.

What makes AMPs unusual in wound care is their dual function: they kill bacteria through membrane disruption while simultaneously signaling the body's own repair machinery to accelerate healing.^[2] This two-pronged mechanism sets them apart from antibiotics, which target infection but do nothing for tissue regeneration.

What Are Antimicrobial Peptides?

Antimicrobial peptides are short chains of amino acids, typically 12 to 50 residues long, that form part of the innate immune system in virtually every multicellular organism. In 1985, Tomas Ganz and colleagues isolated the first human defensins from neutrophils, identifying three small peptides (HNP-1, HNP-2, and HNP-3) that killed Staphylococcus aureus, Pseudomonas aeruginosa, and Escherichia coli in laboratory conditions.^[3] Two years later, Michael Zasloff discovered magainins in the skin of the African clawed frog Xenopus laevis, demonstrating that amphibians produce their own broad-spectrum peptide antibiotics.^[4]

These discoveries revealed a universal defense system. AMPs share several structural features: they are generally cationic (positively charged), amphipathic (containing both hydrophobic and hydrophilic regions), and small enough to interact directly with bacterial cell membranes. Their mechanism of killing differs fundamentally from conventional antibiotics. Rather than targeting a single enzyme or metabolic pathway, most AMPs physically disrupt the bacterial membrane itself, making it far more difficult for bacteria to evolve resistance. For more on how this membrane disruption works at the molecular level, see how antimicrobial peptides kill bacteria.

In the context of wound care, the most studied AMP families include cathelicidins (particularly LL-37 in humans), defensins (both alpha and beta forms), and engineered derivatives of amphibian peptides.

The Dual Role: Infection Control and Wound Healing

The defining characteristic of AMPs in wound care research is that they do two things conventional antibiotics cannot: clear infection and promote tissue repair simultaneously.

Mangoni, McDermott, and Zasloff documented this dual role in their 2016 review, establishing that AMPs serve as "endogenous mediators of wound healing" beyond their antimicrobial function.^[2] The evidence for this comes from multiple lines of research.

Immune modulation. In 2002, Scott and colleagues demonstrated that LL-37 directly upregulated 29 genes and downregulated 20 genes in macrophages. The peptide increased production of chemokines (MCP-1, IL-8) that recruit immune cells to wound sites, while simultaneously suppressing the proinflammatory cytokine TNF-alpha.^[5] This selective modulation means LL-37 brings immune cells to the wound without triggering the excessive inflammation that delays healing.

Cell proliferation and migration. Wang et al. (2022) showed that cathelicidin-DM, an antimicrobial peptide from the toad Duttaphrynus melanostictus, promoted the proliferation of keratinocytes (HaCaT cells), fibroblasts (HSF cells), and endothelial cells (HUVECs) in a concentration-dependent manner. It accelerated fibroblast migration and increased collagen I deposition in mouse wound models, all through activation of the MAPK (ERK, JNK, and P38) signaling pathways.^[6]

Growth factor stimulation. Wu et al. (2018) found that cathelicidin-NV from the plateau frog Nanorana ventripunctata promoted the release of VEGF and TGF-beta1, both critical for angiogenesis and wound contraction. The peptide accelerated re-epithelialization in a murine full-thickness wound model through these growth factor pathways. Cathelicidin-NV showed no cytotoxicity or hemolytic activity at concentrations up to 200 micrograms per milliliter.^[7]

The multifunctional peptide AMP-IBP5, described by Abudouwanli et al. (2025), was specifically engineered to combine both functions in a single molecule. Derived from insulin-like growth factor-binding protein 5, it activates Mas-related G protein-coupled receptors and LRP1 in keratinocytes, stimulating IL-8 production and VEGF expression while maintaining antimicrobial activity against drug-resistant bacteria.^[8] This represents an explicit effort to design peptides that unify infection clearance and tissue repair in a single therapeutic agent. For a broader look at how other peptides approach chronic wounds, see peptides for chronic wound healing.

Key AMP Families in Wound Research

LL-37 and Cathelicidins

LL-37 is the only human cathelicidin and the most extensively studied AMP in wound healing. It is expressed in neutrophils, macrophages, and epithelial cells, and its production increases at wound sites during the inflammatory phase. Its activity extends beyond direct bacterial killing: LL-37 promotes keratinocyte migration, stimulates angiogenesis, and modulates the inflammatory response.^[5]

Luckiewicz et al. (2026) reviewed the accumulated evidence on LL-37 in wound healing, noting that the peptide addresses multiple aspects of chronic wound failure simultaneously: antimicrobial activity, biofilm disruption, inflammation modulation, and promotion of cell migration and proliferation.^[1] The connection between LL-37 and vitamin D signaling is also relevant: vitamin D directly regulates cathelicidin gene expression, meaning vitamin D status may influence wound healing capacity through AMP production. For more on this connection, see vitamin D and LL-37.

The first randomized, placebo-controlled human trial of topical LL-37 for chronic wounds found that the lowest dose tested (0.5 mg/mL) enhanced healing of hard-to-heal venous leg ulcers.^[12] This trial by Gronberg et al. (2014) provided early proof-of-concept that laboratory AMP research translates to human wound healing.

Cathelicidins from amphibian species have also shown wound-healing activity. Cathelicidin-DM accelerated skin wound closure in mice and promoted re-epithelialization and granulation tissue formation.^[6] Cathelicidin-NV enhanced keratinocyte and fibroblast proliferation through MAPK signaling without showing any direct antimicrobial activity, distinguishing it as a pure wound-healing peptide rather than an antimicrobial agent.^[7]

Defensins

Human defensins represent the other major AMP family relevant to wound care. Alpha-defensins (HNP-1 through HNP-3), first isolated by Ganz et al. in 1985, are stored in neutrophil granules and released at wound sites during the inflammatory response.^[3] They kill bacteria, fungi, and even enveloped viruses through direct membrane disruption.

Beta-defensins are produced by epithelial cells, including keratinocytes in the skin, and play a particularly relevant role in wound defense. Da Silva et al. (2025) demonstrated that human beta-defensin 2 (hBD-2) loaded into alginate hydrogels significantly accelerated wound closure in a diabetic mouse model. The hBD-2 hydrogels reduced microbial load, decreased the M1/M2 macrophage ratio (shifting toward a reparative phenotype), lowered reactive oxygen species levels, and increased both neovascularization and collagen deposition.^[9] These findings are relevant because diabetic wounds are among the most difficult to heal, and the results suggest AMPs can address the specific pathological features that make these wounds chronic. For more on this application, see diabetic wound healing and peptide research.

Biofilm: The Hidden Barrier AMPs Can Penetrate

One of the most significant challenges in chronic wound care is bacterial biofilm, a protective matrix of polysaccharides and proteins that bacteria form on wound surfaces. Biofilms are estimated to be present in 60-80% of chronic wounds, and bacteria within biofilms can be 100 to 1,000 times more resistant to antibiotics than their planktonic (free-floating) counterparts.

AMPs show a specific advantage against biofilms that conventional antibiotics lack. Su et al. (2019) developed nanofiber dressings loaded with 17BIPHE2, a molecularly engineered derivative of human cathelicidin LL-37, and tested them against MRSA biofilms in a diabetic wound model. The peptide-containing dressings without debridement caused a five-magnitude decrease in MRSA colony-forming units. When combined with debridement, the dressings completely eliminated the biofilms.^[10] The same peptide nanofibers also killed Klebsiella pneumoniae (10^4 to 10^6 CFU) and Acinetobacter baumannii (10^4 to 10^7 CFU) clinical strains without showing evident cytotoxicity to skin cells.

This biofilm-penetrating ability is mechanistically different from how antibiotics work. While antibiotics need to cross the biofilm matrix and reach their intracellular targets, AMPs can disrupt the biofilm structure itself through electrostatic interactions with the negatively charged matrix components, then kill the bacteria within. For a deeper look at how AMPs work against drug-resistant Staphylococcus specifically, see AMPs against MRSA.

Delivery: Getting AMPs to the Wound

A critical limitation of natural AMPs is their instability in the wound environment. Chronic wounds are rich in proteases, enzymes that rapidly degrade peptides before they can exert their therapeutic effects. This has driven significant research into delivery systems that protect AMPs and provide sustained release.

Hydrogels. Ba et al. (2026) developed a self-healing chitosan hydrogel loaded with FR-20, a self-assembling derivative of LL-37. The hydrogel used dynamic Schiff base cross-linking to provide sustained peptide release, maintained strong bactericidal activity against both E. coli and MRSA, and promoted wound healing in a murine infection model with no detectable systemic toxicity.^[11] The self-healing property is clinically relevant: the hydrogel repairs itself after injection through a needle, maintaining a continuous protective barrier over the wound.

Da Silva et al. (2025) used alginate-based hydrogels to deliver hBD-2, achieving sustained peptide release for over three days with stability across pH 6 to 8, a range relevant to the varying acidity of wound environments.^[9]

Nanofiber dressings. Su et al. (2019) encapsulated engineered cathelicidin peptides in core-shell nanofibers using pluronic F127 and polycaprolactone, achieving an initial burst release followed by sustained delivery over four weeks. This approach eliminated MRSA biofilms in diabetic wound models.^[10] The nanofiber format offers practical advantages for wound care: the dressing can be applied directly to the wound surface and provides both physical protection and active antimicrobial therapy. For a broader look at how peptide-loaded dressings are developing, see our overview of peptide-based wound dressings.

Ceragenins. A different approach avoids the stability problem entirely. Ceragenins are synthetic non-peptide molecules built on a steroid backbone that mimic the antimicrobial activity of LL-37 but resist enzymatic degradation. Luckiewicz et al. (2026) reviewed their potential in wound care, noting that ceragenins maintain activity in the protease-rich wound environment where natural peptides fail. They retain anti-biofilm activity and stability across varying pH and salt conditions.^[1] As non-peptide molecules, ceragenins are potentially cheaper to manufacture than peptide drugs and could be incorporated into wound dressings, hydrogels, or topical formulations.

AMPs vs. Antibiotics in Wound Infection

The comparison between AMPs and conventional antibiotics for wound infection centers on three key differences.

Resistance development. AMPs kill bacteria primarily through physical membrane disruption rather than by targeting specific enzymes or metabolic pathways. Because bacteria would need to fundamentally restructure their membrane composition to resist this mechanism, resistance development is slower and more difficult. Zasloff's original magainin research noted that the peptides' broad-spectrum activity against bacteria, fungi, and protozoa stemmed from this nonspecific membrane interaction.^[4] For more on whether AMPs could serve as antibiotic alternatives, see antimicrobial peptides as alternatives to antibiotics.

Biofilm activity. Antibiotics lose most of their efficacy against bacteria in biofilms, which is a major reason chronic wounds resist treatment. AMPs retain activity against biofilm-embedded bacteria, as demonstrated by the five-log reduction in MRSA biofilm counts with cathelicidin-loaded nanofibers.^[10]

Healing promotion. Antibiotics clear infection but do not contribute to tissue repair. AMPs actively promote wound healing through immune modulation, growth factor stimulation, and cell migration. This dual function means that a single AMP-based treatment could potentially replace a combination of antibiotics plus wound-healing agents.

These advantages come with context. Most evidence for AMP wound therapy comes from preclinical studies, not controlled human trials. Manufacturing costs remain higher than for small-molecule antibiotics. And the optimal dosing, formulation, and application methods for clinical wound care have not been established for most AMPs.

Current Limitations

Stability. Natural AMPs degrade rapidly in the wound environment due to protease activity, pH fluctuations, and salt concentration changes. Every delivery system described above exists specifically to solve this problem, and the number of approaches being tested suggests none has fully solved it yet.

Clinical evidence. Most wound-healing data for AMPs comes from cell culture experiments and animal models. The Gronberg et al. (2014) trial with LL-37 on venous leg ulcers provided early proof-of-concept,^[12] but large-scale randomized controlled trials in human chronic wounds remain limited. The gap between preclinical promise and clinical validation is substantial.

Manufacturing. Peptide synthesis is more expensive than production of small-molecule antibiotics. Ceragenins, as non-peptide mimics, may offer a manufacturing advantage, but their clinical development for wound care is still early-stage.^[1]

Selectivity. While AMPs preferentially target bacterial membranes over mammalian cells, the therapeutic window varies by peptide. Some AMPs show cytotoxicity to human cells at concentrations near their effective antimicrobial dose, which is why molecular engineering to widen this window (as with FR-20 and AMP-IBP5) is an active area of research.^[8][11]

Copper peptides like GHK-Cu take a different approach to wound repair, focusing on tissue remodeling rather than infection control. See GHK-Cu in wound repair and peptides for burn treatment for how other peptide families approach wound healing.

The Bottom Line

Antimicrobial peptides represent a mechanistically distinct approach to wound infection, combining direct pathogen killing with active promotion of tissue repair. The preclinical evidence is substantial across multiple AMP families and delivery systems, with particular strength in biofilm disruption and immune modulation. The field's primary challenge is translating these laboratory and animal model results into validated clinical therapies, a gap that ongoing work in peptide engineering and advanced delivery systems is actively addressing.

Frequently Asked Questions

What are antimicrobial peptides in wound healing?

Antimicrobial peptides are short, naturally occurring molecules that kill wound pathogens by disrupting their cell membranes while also promoting tissue repair through immune modulation and growth factor stimulation. Over 3,200 AMPs have been identified from organisms ranging from frogs to humans, and the human cathelicidin LL-37 is the most studied in wound contexts.^[2]

Can antimicrobial peptides replace antibiotics for wound infections?

AMPs offer advantages over antibiotics for wound infections, including activity against biofilms, slower resistance development, and direct wound-healing promotion. In preclinical studies, engineered cathelicidin peptides eliminated MRSA biofilms in diabetic wound models.^[10] Larger human trials are needed before AMPs can replace antibiotics in routine clinical wound care.

How do antimicrobial peptides kill bacteria differently than antibiotics?

Antibiotics target specific bacterial enzymes or metabolic pathways, which bacteria can mutate to resist. AMPs kill bacteria by physically disrupting their cell membranes through electrostatic attraction between the positively charged peptide and negatively charged bacterial membrane.^[4] This nonspecific mechanism makes resistance development far more difficult.

What is LL-37 and why does it matter for wounds?

LL-37 is the only cathelicidin antimicrobial peptide produced by the human body. It serves dual functions in wounds: killing a broad spectrum of pathogens and modulating the immune response by upregulating chemokines that recruit repair cells while suppressing inflammatory cytokines like TNF-alpha.^[5] Its expression is regulated by vitamin D, linking sun exposure to wound defense capacity.

Why do chronic wounds resist antibiotic treatment?

Chronic wounds typically contain bacterial biofilms, structured communities encased in a protective matrix that makes bacteria 100 to 1,000 times more resistant to antibiotics. Biofilms are present in an estimated 60-80% of chronic wounds. AMPs can penetrate and disrupt biofilm structures through direct electrostatic interactions, which is why they show activity where antibiotics fail.^[10]

Are antimicrobial peptide wound treatments available now?

Most AMP wound therapies are in preclinical or early clinical development. One human trial of topical LL-37 showed positive results for chronic venous leg ulcers.^[12] Delivery systems like peptide-loaded hydrogels and nanofiber dressings have shown strong results in animal models, but validated commercial products for human wound care remain limited. Ceragenins, synthetic AMP mimics that resist degradation in wounds, are among the most advanced candidates approaching clinical application.