Evaluation of low-adherent antimicrobial dressings

Aims: To investigate the physical and antimicrobial properties of low-adherent, silver-containing gelling fibre and certain adhesive foam dressings in vitro. Methods: An in vitro model was used to quantitatively measure fibroblast adhesion to dressings in their dry and hydrated states. Microscopy techniques were used to visualise and quantify aspects of dressing composition and structure. Finally, a flat bacteria-seeded-agar in vitro model was used to semi-quantitatively assess the antimicrobial activity of each dressing and to investigate dressing structure related effects. Results: In vitro cell adhesion to the gelling fibre dressings was significantly less than for the adhesive foam dressings tested (p<0.001), particularly when hydrated. The adhesive foam dressings tested did not prevent bacterial proliferation in this model. In the authors’ opinion, this suggests the adhesive layer of the selected dressings may be a physical barrier to the availability of the antimicrobial agent. Conclusions: Dressing technology and construction may be important factors in determining the adherence properties and antimicrobial activity of dressings. The simple addition of silver to a non-antimicrobial dressing may not necessarily be sufficient to ensure antimicrobial activity. Conflict of interest: The authors (with the exception of Christine Cochrane) are employees of ConvaTec Ltd. Abstract