Laboratory Research
Infections occur in approximately 5.6-26% of wounds, often starting with a low number of colonizing bacteria. To control or treat infected wounds, numerous wound dressings have been created (3,4). In recent years, copper dressings have emerged as an attractive alternative for wound infection (10–12). The aim of this study was to evaluate the efficacy of a novel copper-loaded hydrogel dressing in controlling infection and promoting wound healing using a viable human skin, ex vivo.
Methods:
Antimicrobial nonwoven dressings with copper-loaded hydrogel fibers were evaluated at various copper levels using a human skin model involving viable human skin explants with partial thickness burn wounds and a Staphylococcus aureus MRSA USA300 infection. Explants were treated with copper dressings, commercial silver dressings and compared to non-treated controls for 24 h. Explants were then assessed for bioburden (CFU counts), wound healing (i.e., re-epithelialization via histology), and growth factor analysis (cytokines and chemokines via ELISA).
Results:
Histology staining confirmed the presence of second-degree burn wounds and colonization of bacteria in the surface and superficial layers of the tissue explants. The results showed that the copper dressing having the highest copper loading exhibited the highest antibacterial effect, improved epithelium formation, and decreased wound area compared to the other dressings. Infected wounds showed higher levels of interleukins and cytokines related to infection and inflammation. Markers associated with infection control and wound healing increased in both the copper and silver-treated groups, while the expression of CFD, MIP-3α, and µPAR decreased in both groups. The copper-treated group showed higher expression of FGF-19, CD31, TIM-3, and VCAM-1 and lower expression of IL-1β, IL-18BP, MMP-9, and G-CSF compared to the infected control group. The expression of these markers in the silver-treated group was not statistically different than the control group (p < 0.05).
Discussion: Our results confirmed the efficacy of the novel copper-coated hydrogel dressing, particularly the dressing with the highest copper load, in reducing bacteria and promoting wound healing. This copper dressing prototype offers a potentially important alternative as an absorbent dressing with efficient antibacterial and wound-healing properties relative to currently marketed products