Evaluation of the anti-biofilm activity of a new poly-absorbent dressing with a silver matrix* using a complex in vitro biofilm model
Bacterial biofilms play a significant role in delaying wound healing and are considered to be one of the major challenges in wound infection management. The presence of non-viable tissue, like slough, is a prominent feature of chronic wounds and is considered as a barrier against successful wound healing. A key component of sloughy tissue, fibrin, may play a role in the adhesion of bacteria and the development of the biofilm structures. Moreover, slough may cover the biofilms and provide an additional protection from antimicrobial agents.
This study was designed to evaluate the anti-biofilm activity of a new poly-absorbent dressing with a silver matrix using a complex in vitro biofilm model including a fibrin mesh.
Biofilms of Staphylococcus aureus (methicillin resistant strain – strain MRSA ATCC 43300) and Pseudomonas aeruginosa (strain MRSA ATCC 9027) were formed in well of a polystyrene 6-well plate coated with a collagen type I during 24 hours at 37°C. After biofilm formation, the components needed for the formation of fibrin mesh (fibrinogen, thrombin, buffer CaCl2/NaCl) were added to mimic slough. Then, the formation of the fibrin layer was performed at 37°C for 4 hours.
After incubation, circular samples (34 mm of diameter) of poly-absorbent silver wound dressing which combines polyacrylate fibres and a silver lipido-colloid matrix were placed in contact of these biofilms. After 24 hours of exposure at 32°C and after 48 hours of exposure (with a dressing change), the dressing samples were removed and the capacity of these dressings to trap the fibrin layer and reduce the biofilm was evaluated.
This study allowed us to confirm the anti-biofilm activity of this new poly-absorbent dressing with a silver matrix in a complex in vitro biofilm model.
The composition of the wound dressing which combines polyacrylate fibres and a silver lipido-colloid matrix exhibits an in vitro anti-biofilm activity even in presence of a fibrin layer.