(LR-017) How non-medicated dressings are tested using in vitro and ex vivo test methods
Thursday, May 16, 2024
7:30 PM – 8:30 PM East Coast USA Time
Introduction: Non-medicated wound dressings (NMWD) are a type of dressing that do not contain an active ingredient. NMWD aim to eliminate wound bioburden via mechanisms other than active killing such as debridement and sequestration of microorganisms/toxins. In this study we present a range of in vitro/ ex vivo models aimed to confirm NMWD mode of action.
Methods: Bacterial sequestration was assessed by placing wound dressings inside Pseudomonas aeruginosa and Staphylococcus aureus inoculated trays and incubating for up to 48 hours. After, dressings were transferred onto fresh agar and incubated overnight. The agar under the dressing was observed to demonstrate bacterial retention within the dressing. Sequestration of bacteria was also visualized inside the dressing layers using SEM. Removal of exudate was evaluated using a complex ex vivo mucoid biofilm model. Porcine skin samples, with pre-formed P.aeruginosa 7 days biofilms, were treated with each wound dressing. Remaining viable organisms and total remaining protein were assessed. MMP modulation was assessed by incubating dressings with MMPs for up to 24 hours. After which remaining proteinase concentration was determined.
Results: All three studies showed increased bacterial sequestration, removal of mucoid exudate and MMP modulation of NMWD compared to gauze or other dressing types.
Discussion: In vitro/ex vivo models outlined in this study assess the mode of action of NMWD. Preclinical models are extremely important in predicting clinical performance. In this study, these models can help establish whether NMWD can remove the bioburden at the wound surface without the use of antimicrobial agents.