Application of Antimicrobial Peptides (AMPs) in Treatment of Osteomyelitis in Human and Veterinary Orthopedics

Abstract

Osteomyelitis, a severe bone infection, poses a significant therapeutic challenge in both human and veterinary medicine, especially due to the increasing prevalence of antibiotic-resistant pathogens like methicillin-resistant Staphylococcus aureus (MRSA). Conventional treatments, including surgical debridement and systemic antibiotics, often prove inadequate due to the ability of bacteria to form biofilms and evade host immune responses. Antimicrobial peptides (AMPs), such as LL-37 and β-defensins, have emerged as a promising alternative therapeutic strategy. AMPs exhibit broad-spectrum antimicrobial activity, including efficacy against resistant strains, and possess immunomodulatory properties that can promote bone regeneration. This article comprehensively reviews AMP applications in treating osteomyelitis across both human and veterinary medicine. We discuss diverse therapeutic approaches, including free AMPs, their conjugation with biomaterials such as collagen and chitosan to enhance delivery and stability, and the development of AMP-based nanoparticles. Furthermore, we analyze preclinical and clinical findings, highlighting the efficacy and safety of AMPs in combating osteomyelitis in both human and animal patients. Finally, we explore future perspectives and challenges, such as optimizing delivery, stability, and efficacy, while minimizing cytotoxicity, and in translating AMP-based therapies into clinical practice to effectively manage this debilitating disease.

Keywords: antimicrobial peptides (AMPs); biomaterials; bone infection; bone regeneration; osteomyelitis.

Figure 1

Radiographs of a 17-year-old patient with chronic osteomyelitis of the femur due to infection of an intramedullary nail. The anteroposterior (A) and lateral (B) projections show the presence of osteolytic changes, periosteal reaction, and periosteal calcifications, suggesting a chronic course of infection. Features of bone destruction and lack of proper bone union are visible, which may indicate infection with antibiotic-resistant microorganisms.

Figure 2

Pathophysiology of osteomyelitis. Bacterial infection, primarily caused by S. aureus, leads to microbial adhesion to the bone matrix, biofilm formation, and bone colonization. This triggers activation of the immune system, including B lymphocytes and T cells, resulting in an enhanced inflammatory response. Pro-inflammatory cytokines such as IL-1β and TNF-α stimulate osteoclastogenesis, increasing bone resorption. Compromised blood supply and complement activation contribute to impaired osteoblast proliferation and increased osteoclast activity, ultimately leading to bone tissue destruction and loss of structural integrity.

Figure 3

Osteomyelitis as a problem in veterinary medicine—susceptible species. Osteomyelitis is a serious condition affecting multiple animal species, including dogs, cats, cattle, horses, alpacas, and foals. This pathology can result from bacterial infections, trauma, or postoperative complications.

Figure 4

Techniques for Immobilizing AMPs.

Figure 5

Diagram illustrating the application of antimicrobial peptides (AMPs) in osteomyelitis treatment and animal models used in translational research. On the left, different strategies for AMP immobilization in biomaterials are shown, while on the right, animal models commonly used for studying osteomyelitis therapies in humans are depicted.