Antimicrobial Peptides for Diabetic Foot Ulcers and Infections: Current Evidence and Translational Perspectives

Diabetic foot ulcers (DFU) are among the most severe complications of diabetes, resulting from a combination of metabolic dysregulation, vascular insufficiency, neuropathy, chronic inflammation, and impaired tissue repair, whereas diabetic foot infection (DFI) may develop within this compromised wound environment and frequently involves polymicrobial communities and biofilms. This review evaluates the mechanistic and translational basis for the use of antimicrobial peptides (AMP) in DFU and DFI, with emphasis on the diabetic wound microenvironment, polymicrobial ecology, endogenous AMP dysregulation, mechanisms of action, therapeutic development, and barriers to clinical translation. Hyperglycemia, ischemia, oxidative and proteolytic stress, and impaired innate immunity sustain inflammation, delay tissue repair, and promote microbial persistence. These conditions may also complicate antibiotic treatment through impaired tissue exposure and biofilm-associated tolerance. Depending on the peptide and experimental context, AMP may provide direct antimicrobial or antibiofilm activity and may also exert immunomodulatory or pro-reparative effects involving inflammatory signaling, angiogenesis, keratinocyte and fibroblast migration, and re-epithelialization. Approaches under investigation include engineered peptides, combination regimens, and local biomaterial-based platforms, including hydrogels, dressings, scaffolds, and nanoparticle-conjugated systems. Clinical translation remains constrained by proteolytic instability, potential host-tissue toxicity, limited selectivity, limited predictive value of preclinical models, heterogeneous clinical populations, nonstandardized endpoints, and manufacturing and regulatory requirements. Preclinical evidence supports further evaluation of approaches for local delivery of AMP, whereas clinical evidence in DFU and DFI remains limited and heterogeneous, with no AMP-based intervention yet demonstrating sufficiently consistent clinical benefit to support routine use.