Abstract
Background Biofilms pose a relevant factor for wound healing impairment in chronic wounds. With 78% of all chronic wounds being affected by biofilms, research in this area is of high priority, especially since data for evidence-based selection of appropriate antimicrobials and antiseptics is scarce. Therefore, the objective of this study was to evaluate the anti-biofilm efficacy of commercially available hypochlorous wound irrigation solutions compared to established antiseptics. Methods Using an innovative complex in-vitro human plasma biofilm model (hpBIOM), quantitative reduction of P. aeruginosa , S. aureus and MRSA biofilms by three hypochlorous irrigation solutions (two <0.08% and one 0.2% NaClO) were compared to 0.1% octenidine-dihydrochloride/phenoxyethanol (OCT/PE) and 0.04% polyhexanide (PHMB). Efficacy was compared to a non-challenged planktonic approach as well as with increased substance volume over the prolonged treatment course (up to 72h). Qualitative visualisation of biofilms was performed by scanning electron microscopy (SEM). Results Both tested antiseptics (OCT/PE and PHMB) induced significant biofilm reductions within 72h, whereby OCT/PE in an increased volume even managed complete eradication of P. aeruginosa and MRSA biofilms after 72h. The tested hypochlorous wound irrigation solutions however achieved no relevant penetration and eradication of biofilms, despite increased volume and exposure. Only 0.2% NaClO managed a low reduction over prolonged treatment time. Conclusion The results in the here used complex human plasma biofilm model closely mimic the clinical situation of a high challenging environment for antimicrobials to perform in. Under these conditions, the low-dosed hypochlorous wound irrigation solutions are significantly less effective than antiseptics and thus unsuitable for biofilm eradication.
Efficacy of antiseptics in a novel 3-dimensional human plasma biofilm model (hpBIOM)