In Vitro Protease Activity of an Activated Carbon Cloth Dressing versus a Standard Knitted Viscose Gauze Dressing

Matrix metalloproteinases (MMPs) play an essential role in normal wound healing. Wounds with highly elevated MMPs are associated with delayed healing. Reducing excessive MMP levels in a non-healing wound may convert the wound to a healing state. A low-adherent, 100% pure activated carbon cloth dressing that highly conforms to body contours and maintains contact with the wound surface has been developed as an antimicrobial dressing over dry or discharing partial and full thickness wounds. The purpose of this in vitro study was to evaluate protease activity following 24-hour incubation with an activated carbon cloth dressing compared to a standard knitted viscose gauze dressing. After 24 hours of incubation, the concentrations of MMP-1, 2, 8, and 9 remaining in the gauze supernatant were 0.42 ± 0.06 ngml-1, 3.02 ± 0.04 ngml-1, 0.25 ± 0.13 ngml-1, and 2.66 ± 0.05 ngml-1, respectively. No levels of MMP-1, 2, 8, and 9 were detected in the supernatant incubated with the activated carbon cloth, which corresponds to 100% reduction in these MMP levels compared to the gauze (p < 0.001, p < 0.001, p < 0.05, and p < 0.001, respectively). This study demonstrates that the activated carbon cloth dressing can sequester and retain MMP-1, 2, 8, and 9 within 24 hours, with no detectable concentrations following the 24-hour incubation period. Wound dressings typically remain in situ between 24 and 72 hours. Therefore, the findings from this study suggest that this particular activated carbon cloth dressing could reduce levels of MMP-1, 2, 8, and 9 within the wound bed, which may have useful clinical implications. Based on these promising in vitro results, a randomized, prospective study currently is underway to evaluate how this activated carbon dressing affects MMP levels and healing of chronic wounds of the lower extremity and foot.